v4.19.13 snapshot.
diff --git a/arch/openrisc/kernel/.gitignore b/arch/openrisc/kernel/.gitignore
new file mode 100644
index 0000000..c5f676c
--- /dev/null
+++ b/arch/openrisc/kernel/.gitignore
@@ -0,0 +1 @@
+vmlinux.lds
diff --git a/arch/openrisc/kernel/Makefile b/arch/openrisc/kernel/Makefile
new file mode 100644
index 0000000..2d172e7
--- /dev/null
+++ b/arch/openrisc/kernel/Makefile
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the linux kernel.
+#
+
+extra-y	:= head.o vmlinux.lds
+
+obj-y	:= setup.o or32_ksyms.o process.o dma.o \
+	   traps.o time.o irq.o entry.o ptrace.o signal.o \
+	   sys_call_table.o unwinder.o
+
+obj-$(CONFIG_SMP)		+= smp.o sync-timer.o
+obj-$(CONFIG_STACKTRACE)	+= stacktrace.o
+obj-$(CONFIG_MODULES)		+= module.o
+obj-$(CONFIG_OF)		+= prom.o
+
+clean:
diff --git a/arch/openrisc/kernel/asm-offsets.c b/arch/openrisc/kernel/asm-offsets.c
new file mode 100644
index 0000000..ddb7368
--- /dev/null
+++ b/arch/openrisc/kernel/asm-offsets.c
@@ -0,0 +1,66 @@
+/*
+ * OpenRISC asm-offsets.c
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ *
+ * This program is used to generate definitions needed by
+ * assembly language modules.
+ *
+ * We use the technique used in the OSF Mach kernel code:
+ * generate asm statements containing #defines,
+ * compile this file to assembler, and then extract the
+ * #defines from the assembly-language output.
+ */
+
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/io.h>
+#include <linux/thread_info.h>
+#include <linux/kbuild.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/processor.h>
+
+int main(void)
+{
+	/* offsets into the task_struct */
+	DEFINE(TASK_STATE, offsetof(struct task_struct, state));
+	DEFINE(TASK_FLAGS, offsetof(struct task_struct, flags));
+	DEFINE(TASK_PTRACE, offsetof(struct task_struct, ptrace));
+	DEFINE(TASK_THREAD, offsetof(struct task_struct, thread));
+	DEFINE(TASK_MM, offsetof(struct task_struct, mm));
+	DEFINE(TASK_ACTIVE_MM, offsetof(struct task_struct, active_mm));
+
+	/* offsets into thread_info */
+	DEFINE(TI_TASK, offsetof(struct thread_info, task));
+	DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));
+	DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count));
+	DEFINE(TI_KSP, offsetof(struct thread_info, ksp));
+
+	DEFINE(PT_SIZE, sizeof(struct pt_regs));
+
+	/* Interrupt register frame */
+	DEFINE(STACK_FRAME_OVERHEAD, STACK_FRAME_OVERHEAD);
+	DEFINE(INT_FRAME_SIZE, STACK_FRAME_OVERHEAD + sizeof(struct pt_regs));
+
+	DEFINE(NUM_USER_SEGMENTS, TASK_SIZE >> 28);
+	return 0;
+}
diff --git a/arch/openrisc/kernel/dma.c b/arch/openrisc/kernel/dma.c
new file mode 100644
index 0000000..159336a
--- /dev/null
+++ b/arch/openrisc/kernel/dma.c
@@ -0,0 +1,160 @@
+/*
+ * OpenRISC Linux
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ *
+ * DMA mapping callbacks...
+ * As alloc_coherent is the only DMA callback being used currently, that's
+ * the only thing implemented properly.  The rest need looking into...
+ */
+
+#include <linux/dma-noncoherent.h>
+
+#include <asm/cpuinfo.h>
+#include <asm/spr_defs.h>
+#include <asm/tlbflush.h>
+
+static int
+page_set_nocache(pte_t *pte, unsigned long addr,
+		 unsigned long next, struct mm_walk *walk)
+{
+	unsigned long cl;
+	struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[smp_processor_id()];
+
+	pte_val(*pte) |= _PAGE_CI;
+
+	/*
+	 * Flush the page out of the TLB so that the new page flags get
+	 * picked up next time there's an access
+	 */
+	flush_tlb_page(NULL, addr);
+
+	/* Flush page out of dcache */
+	for (cl = __pa(addr); cl < __pa(next); cl += cpuinfo->dcache_block_size)
+		mtspr(SPR_DCBFR, cl);
+
+	return 0;
+}
+
+static int
+page_clear_nocache(pte_t *pte, unsigned long addr,
+		   unsigned long next, struct mm_walk *walk)
+{
+	pte_val(*pte) &= ~_PAGE_CI;
+
+	/*
+	 * Flush the page out of the TLB so that the new page flags get
+	 * picked up next time there's an access
+	 */
+	flush_tlb_page(NULL, addr);
+
+	return 0;
+}
+
+/*
+ * Alloc "coherent" memory, which for OpenRISC means simply uncached.
+ *
+ * This function effectively just calls __get_free_pages, sets the
+ * cache-inhibit bit on those pages, and makes sure that the pages are
+ * flushed out of the cache before they are used.
+ *
+ * If the NON_CONSISTENT attribute is set, then this function just
+ * returns "normal", cachable memory.
+ *
+ * There are additional flags WEAK_ORDERING and WRITE_COMBINE to take
+ * into consideration here, too.  All current known implementations of
+ * the OR1K support only strongly ordered memory accesses, so that flag
+ * is being ignored for now; uncached but write-combined memory is a
+ * missing feature of the OR1K.
+ */
+void *
+arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
+		gfp_t gfp, unsigned long attrs)
+{
+	unsigned long va;
+	void *page;
+	struct mm_walk walk = {
+		.pte_entry = page_set_nocache,
+		.mm = &init_mm
+	};
+
+	page = alloc_pages_exact(size, gfp);
+	if (!page)
+		return NULL;
+
+	/* This gives us the real physical address of the first page. */
+	*dma_handle = __pa(page);
+
+	va = (unsigned long)page;
+
+	if ((attrs & DMA_ATTR_NON_CONSISTENT) == 0) {
+		/*
+		 * We need to iterate through the pages, clearing the dcache for
+		 * them and setting the cache-inhibit bit.
+		 */
+		if (walk_page_range(va, va + size, &walk)) {
+			free_pages_exact(page, size);
+			return NULL;
+		}
+	}
+
+	return (void *)va;
+}
+
+void
+arch_dma_free(struct device *dev, size_t size, void *vaddr,
+		dma_addr_t dma_handle, unsigned long attrs)
+{
+	unsigned long va = (unsigned long)vaddr;
+	struct mm_walk walk = {
+		.pte_entry = page_clear_nocache,
+		.mm = &init_mm
+	};
+
+	if ((attrs & DMA_ATTR_NON_CONSISTENT) == 0) {
+		/* walk_page_range shouldn't be able to fail here */
+		WARN_ON(walk_page_range(va, va + size, &walk));
+	}
+
+	free_pages_exact(vaddr, size);
+}
+
+void arch_sync_dma_for_device(struct device *dev, phys_addr_t addr, size_t size,
+		enum dma_data_direction dir)
+{
+	unsigned long cl;
+	struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[smp_processor_id()];
+
+	switch (dir) {
+	case DMA_TO_DEVICE:
+		/* Flush the dcache for the requested range */
+		for (cl = addr; cl < addr + size;
+		     cl += cpuinfo->dcache_block_size)
+			mtspr(SPR_DCBFR, cl);
+		break;
+	case DMA_FROM_DEVICE:
+		/* Invalidate the dcache for the requested range */
+		for (cl = addr; cl < addr + size;
+		     cl += cpuinfo->dcache_block_size)
+			mtspr(SPR_DCBIR, cl);
+		break;
+	default:
+		/*
+		 * NOTE: If dir == DMA_BIDIRECTIONAL then there's no need to
+		 * flush nor invalidate the cache here as the area will need
+		 * to be manually synced anyway.
+		 */
+		break;
+	}
+}
diff --git a/arch/openrisc/kernel/entry.S b/arch/openrisc/kernel/entry.S
new file mode 100644
index 0000000..0c826ad
--- /dev/null
+++ b/arch/openrisc/kernel/entry.S
@@ -0,0 +1,1218 @@
+/*
+ * OpenRISC entry.S
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2005 Gyorgy Jeney <nog@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/linkage.h>
+
+#include <asm/processor.h>
+#include <asm/unistd.h>
+#include <asm/thread_info.h>
+#include <asm/errno.h>
+#include <asm/spr_defs.h>
+#include <asm/page.h>
+#include <asm/mmu.h>
+#include <asm/pgtable.h>
+#include <asm/asm-offsets.h>
+
+#define DISABLE_INTERRUPTS(t1,t2)			\
+	l.mfspr t2,r0,SPR_SR				;\
+	l.movhi	t1,hi(~(SPR_SR_IEE|SPR_SR_TEE))		;\
+	l.ori	t1,t1,lo(~(SPR_SR_IEE|SPR_SR_TEE))	;\
+	l.and   t2,t2,t1				;\
+	l.mtspr r0,t2,SPR_SR
+
+#define ENABLE_INTERRUPTS(t1)				\
+	l.mfspr	t1,r0,SPR_SR				;\
+	l.ori	t1,t1,lo(SPR_SR_IEE|SPR_SR_TEE)		;\
+	l.mtspr	r0,t1,SPR_SR
+
+/* =========================================================[ macros ]=== */
+
+#ifdef CONFIG_TRACE_IRQFLAGS
+/*
+ * Trace irq on/off creating a stack frame.
+ */
+#define TRACE_IRQS_OP(trace_op)					\
+	l.sw 	-8(r1),r2	/* store frame pointer */		;\
+	l.sw	-4(r1),r9	/* store return address */		;\
+	l.addi	r2,r1,0		/* move sp to fp */			;\
+	l.jal	trace_op						;\
+	 l.addi	r1,r1,-8						;\
+	l.ori	r1,r2,0		/* restore sp */			;\
+	l.lwz	r9,-4(r1)	/* restore return address */		;\
+	l.lwz	r2,-8(r1)	/* restore fp */			;\
+/*
+ * Trace irq on/off and save registers we need that would otherwise be
+ * clobbered.
+ */
+#define TRACE_IRQS_SAVE(t1,trace_op)					\
+	l.sw	-12(r1),t1	/* save extra reg */			;\
+	l.sw 	-8(r1),r2	/* store frame pointer */		;\
+	l.sw	-4(r1),r9	/* store return address */		;\
+	l.addi	r2,r1,0		/* move sp to fp */			;\
+	l.jal	trace_op						;\
+	 l.addi	r1,r1,-12						;\
+	l.ori	r1,r2,0		/* restore sp */			;\
+	l.lwz	r9,-4(r1)	/* restore return address */		;\
+	l.lwz	r2,-8(r1)	/* restore fp */			;\
+	l.lwz	t1,-12(r1)	/* restore extra reg */
+
+#define TRACE_IRQS_OFF	TRACE_IRQS_OP(trace_hardirqs_off)
+#define TRACE_IRQS_ON	TRACE_IRQS_OP(trace_hardirqs_on)
+#define TRACE_IRQS_ON_SYSCALL						\
+	TRACE_IRQS_SAVE(r10,trace_hardirqs_on)				;\
+	l.lwz	r3,PT_GPR3(r1)						;\
+	l.lwz	r4,PT_GPR4(r1)						;\
+	l.lwz	r5,PT_GPR5(r1)						;\
+	l.lwz	r6,PT_GPR6(r1)						;\
+	l.lwz	r7,PT_GPR7(r1)						;\
+	l.lwz	r8,PT_GPR8(r1)						;\
+	l.lwz	r11,PT_GPR11(r1)
+#define TRACE_IRQS_OFF_ENTRY						\
+	l.lwz	r5,PT_SR(r1)						;\
+	l.andi	r3,r5,(SPR_SR_IEE|SPR_SR_TEE)				;\
+	l.sfeq	r5,r0		/* skip trace if irqs were already off */;\
+	l.bf	1f							;\
+	 l.nop								;\
+	TRACE_IRQS_SAVE(r4,trace_hardirqs_off)				;\
+1:
+#else
+#define TRACE_IRQS_OFF
+#define TRACE_IRQS_ON
+#define TRACE_IRQS_OFF_ENTRY
+#define TRACE_IRQS_ON_SYSCALL
+#endif
+
+/*
+ * We need to disable interrupts at beginning of RESTORE_ALL
+ * since interrupt might come in after we've loaded EPC return address
+ * and overwrite EPC with address somewhere in RESTORE_ALL
+ * which is of course wrong!
+ */
+
+#define RESTORE_ALL						\
+	DISABLE_INTERRUPTS(r3,r4)				;\
+	l.lwz   r3,PT_PC(r1)					;\
+	l.mtspr r0,r3,SPR_EPCR_BASE				;\
+	l.lwz   r3,PT_SR(r1)					;\
+	l.mtspr r0,r3,SPR_ESR_BASE				;\
+	l.lwz   r2,PT_GPR2(r1)					;\
+	l.lwz   r3,PT_GPR3(r1)					;\
+	l.lwz   r4,PT_GPR4(r1)					;\
+	l.lwz   r5,PT_GPR5(r1)					;\
+	l.lwz   r6,PT_GPR6(r1)					;\
+	l.lwz   r7,PT_GPR7(r1)					;\
+	l.lwz   r8,PT_GPR8(r1)					;\
+	l.lwz   r9,PT_GPR9(r1)					;\
+	l.lwz   r10,PT_GPR10(r1)					;\
+	l.lwz   r11,PT_GPR11(r1)					;\
+	l.lwz   r12,PT_GPR12(r1)					;\
+	l.lwz   r13,PT_GPR13(r1)					;\
+	l.lwz   r14,PT_GPR14(r1)					;\
+	l.lwz   r15,PT_GPR15(r1)					;\
+	l.lwz   r16,PT_GPR16(r1)					;\
+	l.lwz   r17,PT_GPR17(r1)					;\
+	l.lwz   r18,PT_GPR18(r1)					;\
+	l.lwz   r19,PT_GPR19(r1)					;\
+	l.lwz   r20,PT_GPR20(r1)					;\
+	l.lwz   r21,PT_GPR21(r1)					;\
+	l.lwz   r22,PT_GPR22(r1)					;\
+	l.lwz   r23,PT_GPR23(r1)					;\
+	l.lwz   r24,PT_GPR24(r1)					;\
+	l.lwz   r25,PT_GPR25(r1)					;\
+	l.lwz   r26,PT_GPR26(r1)					;\
+	l.lwz   r27,PT_GPR27(r1)					;\
+	l.lwz   r28,PT_GPR28(r1)					;\
+	l.lwz   r29,PT_GPR29(r1)					;\
+	l.lwz   r30,PT_GPR30(r1)					;\
+	l.lwz   r31,PT_GPR31(r1)					;\
+	l.lwz   r1,PT_SP(r1)					;\
+	l.rfe
+
+
+#define EXCEPTION_ENTRY(handler)				\
+	.global	handler						;\
+handler:							;\
+	/* r1, EPCR, ESR a already saved */			;\
+	l.sw	PT_GPR2(r1),r2					;\
+	l.sw    PT_GPR3(r1),r3					;\
+	/* r4 already save */					;\
+	l.sw    PT_GPR5(r1),r5					;\
+	l.sw    PT_GPR6(r1),r6					;\
+	l.sw    PT_GPR7(r1),r7					;\
+	l.sw    PT_GPR8(r1),r8					;\
+	l.sw    PT_GPR9(r1),r9					;\
+	/* r10 already saved */					;\
+	l.sw    PT_GPR11(r1),r11					;\
+	/* r12 already saved */					;\
+	l.sw    PT_GPR13(r1),r13					;\
+	l.sw    PT_GPR14(r1),r14					;\
+	l.sw    PT_GPR15(r1),r15					;\
+	l.sw    PT_GPR16(r1),r16					;\
+	l.sw    PT_GPR17(r1),r17					;\
+	l.sw    PT_GPR18(r1),r18					;\
+	l.sw    PT_GPR19(r1),r19					;\
+	l.sw    PT_GPR20(r1),r20					;\
+	l.sw    PT_GPR21(r1),r21					;\
+	l.sw    PT_GPR22(r1),r22					;\
+	l.sw    PT_GPR23(r1),r23					;\
+	l.sw    PT_GPR24(r1),r24					;\
+	l.sw    PT_GPR25(r1),r25					;\
+	l.sw    PT_GPR26(r1),r26					;\
+	l.sw    PT_GPR27(r1),r27					;\
+	l.sw    PT_GPR28(r1),r28					;\
+	l.sw    PT_GPR29(r1),r29					;\
+	/* r30 already save */					;\
+/*        l.sw    PT_GPR30(r1),r30*/					;\
+	l.sw    PT_GPR31(r1),r31					;\
+	TRACE_IRQS_OFF_ENTRY						;\
+	/* Store -1 in orig_gpr11 for non-syscall exceptions */	;\
+	l.addi	r30,r0,-1					;\
+	l.sw	PT_ORIG_GPR11(r1),r30
+
+#define UNHANDLED_EXCEPTION(handler,vector)			\
+	.global	handler						;\
+handler:							;\
+	/* r1, EPCR, ESR already saved */			;\
+	l.sw    PT_GPR2(r1),r2					;\
+	l.sw    PT_GPR3(r1),r3					;\
+	l.sw    PT_GPR5(r1),r5					;\
+	l.sw    PT_GPR6(r1),r6					;\
+	l.sw    PT_GPR7(r1),r7					;\
+	l.sw    PT_GPR8(r1),r8					;\
+	l.sw    PT_GPR9(r1),r9					;\
+	/* r10 already saved */					;\
+	l.sw    PT_GPR11(r1),r11					;\
+	/* r12 already saved */					;\
+	l.sw    PT_GPR13(r1),r13					;\
+	l.sw    PT_GPR14(r1),r14					;\
+	l.sw    PT_GPR15(r1),r15					;\
+	l.sw    PT_GPR16(r1),r16					;\
+	l.sw    PT_GPR17(r1),r17					;\
+	l.sw    PT_GPR18(r1),r18					;\
+	l.sw    PT_GPR19(r1),r19					;\
+	l.sw    PT_GPR20(r1),r20					;\
+	l.sw    PT_GPR21(r1),r21					;\
+	l.sw    PT_GPR22(r1),r22					;\
+	l.sw    PT_GPR23(r1),r23					;\
+	l.sw    PT_GPR24(r1),r24					;\
+	l.sw    PT_GPR25(r1),r25					;\
+	l.sw    PT_GPR26(r1),r26					;\
+	l.sw    PT_GPR27(r1),r27					;\
+	l.sw    PT_GPR28(r1),r28					;\
+	l.sw    PT_GPR29(r1),r29					;\
+	/* r31 already saved */					;\
+	l.sw    PT_GPR30(r1),r30					;\
+/*        l.sw    PT_GPR31(r1),r31	*/				;\
+	/* Store -1 in orig_gpr11 for non-syscall exceptions */	;\
+	l.addi	r30,r0,-1					;\
+	l.sw	PT_ORIG_GPR11(r1),r30				;\
+	l.addi	r3,r1,0						;\
+	/* r4 is exception EA */				;\
+	l.addi	r5,r0,vector					;\
+	l.jal	unhandled_exception				;\
+	 l.nop							;\
+	l.j	_ret_from_exception				;\
+	 l.nop
+
+/* clobbers 'reg' */
+#define CLEAR_LWA_FLAG(reg)		\
+	l.movhi	reg,hi(lwa_flag)	;\
+	l.ori	reg,reg,lo(lwa_flag)	;\
+	l.sw	0(reg),r0
+/*
+ * NOTE: one should never assume that SPR_EPC, SPR_ESR, SPR_EEAR
+ *       contain the same values as when exception we're handling
+ *	 occured. in fact they never do. if you need them use
+ *	 values saved on stack (for SPR_EPC, SPR_ESR) or content
+ *       of r4 (for SPR_EEAR). for details look at EXCEPTION_HANDLE()
+ *       in 'arch/or32/kernel/head.S'
+ */
+
+/* =====================================================[ exceptions] === */
+
+/* ---[ 0x100: RESET exception ]----------------------------------------- */
+
+EXCEPTION_ENTRY(_tng_kernel_start)
+	l.jal	_start
+	 l.andi r0,r0,0
+
+/* ---[ 0x200: BUS exception ]------------------------------------------- */
+
+EXCEPTION_ENTRY(_bus_fault_handler)
+	CLEAR_LWA_FLAG(r3)
+	/* r4: EA of fault (set by EXCEPTION_HANDLE) */
+	l.jal   do_bus_fault
+	 l.addi  r3,r1,0 /* pt_regs */
+
+	l.j     _ret_from_exception
+	 l.nop
+
+/* ---[ 0x300: Data Page Fault exception ]------------------------------- */
+EXCEPTION_ENTRY(_dtlb_miss_page_fault_handler)
+	CLEAR_LWA_FLAG(r3)
+	l.and	r5,r5,r0
+	l.j	1f
+	 l.nop
+
+EXCEPTION_ENTRY(_data_page_fault_handler)
+	CLEAR_LWA_FLAG(r3)
+	/* set up parameters for do_page_fault */
+	l.ori	r5,r0,0x300		   // exception vector
+1:
+	l.addi  r3,r1,0                    // pt_regs
+	/* r4 set be EXCEPTION_HANDLE */   // effective address of fault
+
+#ifdef CONFIG_OPENRISC_NO_SPR_SR_DSX
+	l.lwz   r6,PT_PC(r3)               // address of an offending insn
+	l.lwz   r6,0(r6)                   // instruction that caused pf
+
+	l.srli  r6,r6,26                   // check opcode for jump insn
+	l.sfeqi r6,0                       // l.j
+	l.bf    8f
+	l.sfeqi r6,1                       // l.jal
+	l.bf    8f
+	l.sfeqi r6,3                       // l.bnf
+	l.bf    8f
+	l.sfeqi r6,4                       // l.bf
+	l.bf    8f
+	l.sfeqi r6,0x11                    // l.jr
+	l.bf    8f
+	l.sfeqi r6,0x12                    // l.jalr
+	l.bf    8f
+	 l.nop
+
+	l.j     9f
+	 l.nop
+
+8: // offending insn is in delay slot
+	l.lwz   r6,PT_PC(r3)               // address of an offending insn
+	l.addi  r6,r6,4
+	l.lwz   r6,0(r6)                   // instruction that caused pf
+	l.srli  r6,r6,26                   // get opcode
+9: // offending instruction opcode loaded in r6
+
+#else
+
+	l.mfspr r6,r0,SPR_SR               // SR
+	l.andi  r6,r6,SPR_SR_DSX           // check for delay slot exception
+	l.sfne  r6,r0                      // exception happened in delay slot
+	l.bnf   7f
+	 l.lwz  r6,PT_PC(r3)               // address of an offending insn
+
+	l.addi	r6,r6,4                    // offending insn is in delay slot
+7:
+	l.lwz   r6,0(r6)                   // instruction that caused pf
+	l.srli  r6,r6,26                   // check opcode for write access
+#endif
+
+	l.sfgeui r6,0x33                   // check opcode for write access
+	l.bnf   1f
+	l.sfleui r6,0x37
+	l.bnf   1f
+	l.ori   r6,r0,0x1                  // write access
+	l.j     2f
+	 l.nop
+1:	l.ori   r6,r0,0x0                  // !write access
+2:
+
+	/* call fault.c handler in or32/mm/fault.c */
+	l.jal   do_page_fault
+	 l.nop
+	l.j     _ret_from_exception
+	 l.nop
+
+/* ---[ 0x400: Insn Page Fault exception ]------------------------------- */
+EXCEPTION_ENTRY(_itlb_miss_page_fault_handler)
+	CLEAR_LWA_FLAG(r3)
+	l.and	r5,r5,r0
+	l.j	1f
+	 l.nop
+
+EXCEPTION_ENTRY(_insn_page_fault_handler)
+	CLEAR_LWA_FLAG(r3)
+	/* set up parameters for do_page_fault */
+	l.ori	r5,r0,0x400		   // exception vector
+1:
+	l.addi  r3,r1,0                    // pt_regs
+	/* r4 set be EXCEPTION_HANDLE */   // effective address of fault
+	l.ori	r6,r0,0x0		   // !write access
+
+	/* call fault.c handler in or32/mm/fault.c */
+	l.jal   do_page_fault
+	 l.nop
+	l.j     _ret_from_exception
+	 l.nop
+
+
+/* ---[ 0x500: Timer exception ]----------------------------------------- */
+
+EXCEPTION_ENTRY(_timer_handler)
+	CLEAR_LWA_FLAG(r3)
+	l.jal	timer_interrupt
+	 l.addi r3,r1,0 /* pt_regs */
+
+	l.j    _ret_from_intr
+	 l.nop
+
+/* ---[ 0x600: Alignment exception ]-------------------------------------- */
+
+EXCEPTION_ENTRY(_alignment_handler)
+	CLEAR_LWA_FLAG(r3)
+	/* r4: EA of fault (set by EXCEPTION_HANDLE) */
+	l.jal   do_unaligned_access
+	 l.addi  r3,r1,0 /* pt_regs */
+
+	l.j     _ret_from_exception
+	 l.nop
+
+#if 0
+EXCEPTION_ENTRY(_alignment_handler)
+//        l.mfspr r2,r0,SPR_EEAR_BASE     /* Load the effective address */
+	l.addi	r2,r4,0
+//        l.mfspr r5,r0,SPR_EPCR_BASE     /* Load the insn address */
+	l.lwz   r5,PT_PC(r1)
+
+	l.lwz   r3,0(r5)                /* Load insn */
+	l.srli  r4,r3,26                /* Shift left to get the insn opcode */
+
+	l.sfeqi r4,0x00                 /* Check if the load/store insn is in delay slot */
+	l.bf    jmp
+	l.sfeqi r4,0x01
+	l.bf    jmp
+	l.sfeqi r4,0x03
+	l.bf    jmp
+	l.sfeqi r4,0x04
+	l.bf    jmp
+	l.sfeqi r4,0x11
+	l.bf    jr
+	l.sfeqi r4,0x12
+	l.bf    jr
+	l.nop
+	l.j     1f
+	l.addi  r5,r5,4                 /* Increment PC to get return insn address */
+
+jmp:
+	l.slli  r4,r3,6                 /* Get the signed extended jump length */
+	l.srai  r4,r4,4
+
+	l.lwz   r3,4(r5)                /* Load the real load/store insn */
+
+	l.add   r5,r5,r4                /* Calculate jump target address */
+
+	l.j     1f
+	l.srli  r4,r3,26                /* Shift left to get the insn opcode */
+
+jr:
+	l.slli  r4,r3,9                 /* Shift to get the reg nb */
+	l.andi  r4,r4,0x7c
+
+	l.lwz   r3,4(r5)                /* Load the real load/store insn */
+
+	l.add   r4,r4,r1                /* Load the jump register value from the stack */
+	l.lwz   r5,0(r4)
+
+	l.srli  r4,r3,26                /* Shift left to get the insn opcode */
+
+
+1:
+//	  l.mtspr r0,r5,SPR_EPCR_BASE
+	l.sw	PT_PC(r1),r5
+
+	l.sfeqi r4,0x26
+	l.bf    lhs
+	l.sfeqi r4,0x25
+	l.bf    lhz
+	l.sfeqi r4,0x22
+	l.bf    lws
+	l.sfeqi r4,0x21
+	l.bf    lwz
+	l.sfeqi r4,0x37
+	l.bf    sh
+	l.sfeqi r4,0x35
+	l.bf    sw
+	l.nop
+
+1:      l.j     1b                      /* I don't know what to do */
+	l.nop
+
+lhs:    l.lbs   r5,0(r2)
+	l.slli  r5,r5,8
+	l.lbz   r6,1(r2)
+	l.or    r5,r5,r6
+	l.srli  r4,r3,19
+	l.andi  r4,r4,0x7c
+	l.add   r4,r4,r1
+	l.j     align_end
+	l.sw    0(r4),r5
+
+lhz:    l.lbz   r5,0(r2)
+	l.slli  r5,r5,8
+	l.lbz   r6,1(r2)
+	l.or    r5,r5,r6
+	l.srli  r4,r3,19
+	l.andi  r4,r4,0x7c
+	l.add   r4,r4,r1
+	l.j     align_end
+	l.sw    0(r4),r5
+
+lws:    l.lbs   r5,0(r2)
+	l.slli  r5,r5,24
+	l.lbz   r6,1(r2)
+	l.slli  r6,r6,16
+	l.or    r5,r5,r6
+	l.lbz   r6,2(r2)
+	l.slli  r6,r6,8
+	l.or    r5,r5,r6
+	l.lbz   r6,3(r2)
+	l.or    r5,r5,r6
+	l.srli  r4,r3,19
+	l.andi  r4,r4,0x7c
+	l.add   r4,r4,r1
+	l.j     align_end
+	l.sw    0(r4),r5
+
+lwz:    l.lbz   r5,0(r2)
+	l.slli  r5,r5,24
+	l.lbz   r6,1(r2)
+	l.slli  r6,r6,16
+	l.or    r5,r5,r6
+	l.lbz   r6,2(r2)
+	l.slli  r6,r6,8
+	l.or    r5,r5,r6
+	l.lbz   r6,3(r2)
+	l.or    r5,r5,r6
+	l.srli  r4,r3,19
+	l.andi  r4,r4,0x7c
+	l.add   r4,r4,r1
+	l.j     align_end
+	l.sw    0(r4),r5
+
+sh:
+	l.srli  r4,r3,9
+	l.andi  r4,r4,0x7c
+	l.add   r4,r4,r1
+	l.lwz   r5,0(r4)
+	l.sb    1(r2),r5
+	l.srli  r5,r5,8
+	l.j     align_end
+	l.sb    0(r2),r5
+
+sw:
+	l.srli  r4,r3,9
+	l.andi  r4,r4,0x7c
+	l.add   r4,r4,r1
+	l.lwz   r5,0(r4)
+	l.sb    3(r2),r5
+	l.srli  r5,r5,8
+	l.sb    2(r2),r5
+	l.srli  r5,r5,8
+	l.sb    1(r2),r5
+	l.srli  r5,r5,8
+	l.j     align_end
+	l.sb    0(r2),r5
+
+align_end:
+	l.j    _ret_from_intr
+	l.nop
+#endif
+
+/* ---[ 0x700: Illegal insn exception ]---------------------------------- */
+
+EXCEPTION_ENTRY(_illegal_instruction_handler)
+	/* r4: EA of fault (set by EXCEPTION_HANDLE) */
+	l.jal   do_illegal_instruction
+	 l.addi  r3,r1,0 /* pt_regs */
+
+	l.j     _ret_from_exception
+	 l.nop
+
+/* ---[ 0x800: External interrupt exception ]---------------------------- */
+
+EXCEPTION_ENTRY(_external_irq_handler)
+#ifdef CONFIG_OPENRISC_ESR_EXCEPTION_BUG_CHECK
+	l.lwz	r4,PT_SR(r1)		// were interrupts enabled ?
+	l.andi	r4,r4,SPR_SR_IEE
+	l.sfeqi	r4,0
+	l.bnf	1f			// ext irq enabled, all ok.
+	l.nop
+
+	l.addi  r1,r1,-0x8
+	l.movhi r3,hi(42f)
+	l.ori	r3,r3,lo(42f)
+	l.sw    0x0(r1),r3
+	l.jal   printk
+	l.sw    0x4(r1),r4
+	l.addi  r1,r1,0x8
+
+	.section .rodata, "a"
+42:
+		.string "\n\rESR interrupt bug: in _external_irq_handler (ESR %x)\n\r"
+		.align 4
+	.previous
+
+	l.ori	r4,r4,SPR_SR_IEE	// fix the bug
+//	l.sw	PT_SR(r1),r4
+1:
+#endif
+	CLEAR_LWA_FLAG(r3)
+	l.addi	r3,r1,0
+	l.movhi	r8,hi(do_IRQ)
+	l.ori	r8,r8,lo(do_IRQ)
+	l.jalr r8
+	l.nop
+	l.j    _ret_from_intr
+	l.nop
+
+/* ---[ 0x900: DTLB miss exception ]------------------------------------- */
+
+
+/* ---[ 0xa00: ITLB miss exception ]------------------------------------- */
+
+
+/* ---[ 0xb00: Range exception ]----------------------------------------- */
+
+UNHANDLED_EXCEPTION(_vector_0xb00,0xb00)
+
+/* ---[ 0xc00: Syscall exception ]--------------------------------------- */
+
+/*
+ * Syscalls are a special type of exception in that they are
+ * _explicitly_ invoked by userspace and can therefore be
+ * held to conform to the same ABI as normal functions with
+ * respect to whether registers are preserved across the call
+ * or not.
+ */
+
+/* Upon syscall entry we just save the callee-saved registers
+ * and not the call-clobbered ones.
+ */
+
+_string_syscall_return:
+	.string "syscall return %ld \n\r\0"
+	.align 4
+
+ENTRY(_sys_call_handler)
+	/* r1, EPCR, ESR a already saved */
+	l.sw	PT_GPR2(r1),r2
+	/* r3-r8 must be saved because syscall restart relies
+	 * on us being able to restart the syscall args... technically
+	 * they should be clobbered, otherwise
+	 */
+	l.sw    PT_GPR3(r1),r3
+	/*
+	 * r4 already saved
+	 * r4 holds the EEAR address of the fault, use it as screatch reg and
+	 * then load the original r4
+	 */
+	CLEAR_LWA_FLAG(r4)
+	l.lwz	r4,PT_GPR4(r1)
+	l.sw    PT_GPR5(r1),r5
+	l.sw    PT_GPR6(r1),r6
+	l.sw    PT_GPR7(r1),r7
+	l.sw    PT_GPR8(r1),r8
+	l.sw    PT_GPR9(r1),r9
+	/* r10 already saved */
+	l.sw    PT_GPR11(r1),r11
+	/* orig_gpr11 must be set for syscalls */
+	l.sw    PT_ORIG_GPR11(r1),r11
+	/* r12,r13 already saved */
+
+	/* r14-r28 (even) aren't touched by the syscall fast path below
+	 * so we don't need to save them.  However, the functions that return
+	 * to userspace via a call to switch() DO need to save these because
+	 * switch() effectively clobbers them... saving these registers for
+	 * such functions is handled in their syscall wrappers (see fork, vfork,
+	 * and clone, below).
+
+	/* r30 is the only register we clobber in the fast path */
+	/* r30 already saved */
+/*	l.sw    PT_GPR30(r1),r30 */
+
+_syscall_check_trace_enter:
+	/* syscalls run with interrupts enabled */
+	TRACE_IRQS_ON_SYSCALL
+	ENABLE_INTERRUPTS(r29)		// enable interrupts, r29 is temp
+
+	/* If TIF_SYSCALL_TRACE is set, then we want to do syscall tracing */
+	l.lwz	r30,TI_FLAGS(r10)
+	l.andi	r30,r30,_TIF_SYSCALL_TRACE
+	l.sfne	r30,r0
+	l.bf	_syscall_trace_enter
+	 l.nop
+
+_syscall_check:
+	/* Ensure that the syscall number is reasonable */
+	l.sfgeui r11,__NR_syscalls
+	l.bf	_syscall_badsys
+	 l.nop
+
+_syscall_call:
+	l.movhi r29,hi(sys_call_table)
+	l.ori   r29,r29,lo(sys_call_table)
+	l.slli  r11,r11,2
+	l.add   r29,r29,r11
+	l.lwz   r29,0(r29)
+
+	l.jalr  r29
+	 l.nop
+
+_syscall_return:
+	/* All syscalls return here... just pay attention to ret_from_fork
+	 * which does it in a round-about way.
+	 */
+	l.sw    PT_GPR11(r1),r11           // save return value
+
+#if 0
+_syscall_debug:
+	l.movhi r3,hi(_string_syscall_return)
+	l.ori   r3,r3,lo(_string_syscall_return)
+	l.ori   r27,r0,1
+	l.sw    -4(r1),r27
+	l.sw    -8(r1),r11
+	l.addi  r1,r1,-8
+	l.movhi r27,hi(printk)
+	l.ori   r27,r27,lo(printk)
+	l.jalr  r27
+	 l.nop
+	l.addi  r1,r1,8
+#endif
+
+_syscall_check_trace_leave:
+	/* r30 is a callee-saved register so this should still hold the
+	 * _TIF_SYSCALL_TRACE flag from _syscall_check_trace_enter above...
+	 * _syscall_trace_leave expects syscall result to be in pt_regs->r11.
+	 */
+	l.sfne	r30,r0
+	l.bf	_syscall_trace_leave
+	 l.nop
+
+/* This is where the exception-return code begins... interrupts need to be
+ * disabled the rest of the way here because we can't afford to miss any
+ * interrupts that set NEED_RESCHED or SIGNALPENDING... really true? */
+
+_syscall_check_work:
+	/* Here we need to disable interrupts */
+	DISABLE_INTERRUPTS(r27,r29)
+	TRACE_IRQS_OFF
+	l.lwz	r30,TI_FLAGS(r10)
+	l.andi	r30,r30,_TIF_WORK_MASK
+	l.sfne	r30,r0
+
+	l.bnf	_syscall_resume_userspace
+	 l.nop
+
+	/* Work pending follows a different return path, so we need to
+	 * make sure that all the call-saved registers get into pt_regs
+	 * before branching...
+	 */
+	l.sw    PT_GPR14(r1),r14
+	l.sw    PT_GPR16(r1),r16
+	l.sw    PT_GPR18(r1),r18
+	l.sw    PT_GPR20(r1),r20
+	l.sw    PT_GPR22(r1),r22
+	l.sw    PT_GPR24(r1),r24
+	l.sw    PT_GPR26(r1),r26
+	l.sw    PT_GPR28(r1),r28
+
+	/* _work_pending needs to be called with interrupts disabled */
+	l.j	_work_pending
+	 l.nop
+
+_syscall_resume_userspace:
+//	ENABLE_INTERRUPTS(r29)
+
+
+/* This is the hot path for returning to userspace from a syscall.  If there's
+ * work to be done and the branch to _work_pending was taken above, then the
+ * return to userspace will be done via the normal exception return path...
+ * that path restores _all_ registers and will overwrite the "clobbered"
+ * registers with whatever garbage is in pt_regs -- that's OK because those
+ * registers are clobbered anyway and because the extra work is insignificant
+ * in the context of the extra work that _work_pending is doing.
+
+/* Once again, syscalls are special and only guarantee to preserve the
+ * same registers as a normal function call */
+
+/* The assumption here is that the registers r14-r28 (even) are untouched and
+ * don't need to be restored... be sure that that's really the case!
+ */
+
+/* This is still too much... we should only be restoring what we actually
+ * clobbered... we should even be using 'scratch' (odd) regs above so that
+ * we don't need to restore anything, hardly...
+ */
+
+	l.lwz	r2,PT_GPR2(r1)
+
+	/* Restore args */
+	/* r3-r8 are technically clobbered, but syscall restart needs these
+	 * to be restored...
+	 */
+	l.lwz	r3,PT_GPR3(r1)
+	l.lwz	r4,PT_GPR4(r1)
+	l.lwz	r5,PT_GPR5(r1)
+	l.lwz	r6,PT_GPR6(r1)
+	l.lwz	r7,PT_GPR7(r1)
+	l.lwz	r8,PT_GPR8(r1)
+
+	l.lwz	r9,PT_GPR9(r1)
+	l.lwz	r10,PT_GPR10(r1)
+	l.lwz	r11,PT_GPR11(r1)
+
+	/* r30 is the only register we clobber in the fast path */
+	l.lwz	r30,PT_GPR30(r1)
+
+	/* Here we use r13-r19 (odd) as scratch regs */
+	l.lwz   r13,PT_PC(r1)
+	l.lwz   r15,PT_SR(r1)
+	l.lwz	r1,PT_SP(r1)
+	/* Interrupts need to be disabled for setting EPCR and ESR
+	 * so that another interrupt doesn't come in here and clobber
+	 * them before we can use them for our l.rfe */
+	DISABLE_INTERRUPTS(r17,r19)
+	l.mtspr r0,r13,SPR_EPCR_BASE
+	l.mtspr r0,r15,SPR_ESR_BASE
+	l.rfe
+
+/* End of hot path!
+ * Keep the below tracing and error handling out of the hot path...
+*/
+
+_syscall_trace_enter:
+	/* Here we pass pt_regs to do_syscall_trace_enter.  Make sure
+	 * that function is really getting all the info it needs as
+	 * pt_regs isn't a complete set of userspace regs, just the
+	 * ones relevant to the syscall...
+	 *
+	 * Note use of delay slot for setting argument.
+	 */
+	l.jal	do_syscall_trace_enter
+	 l.addi	r3,r1,0
+
+	/* Restore arguments (not preserved across do_syscall_trace_enter)
+	 * so that we can do the syscall for real and return to the syscall
+	 * hot path.
+	 */
+	l.lwz	r11,PT_GPR11(r1)
+	l.lwz	r3,PT_GPR3(r1)
+	l.lwz	r4,PT_GPR4(r1)
+	l.lwz	r5,PT_GPR5(r1)
+	l.lwz	r6,PT_GPR6(r1)
+	l.lwz	r7,PT_GPR7(r1)
+
+	l.j	_syscall_check
+	 l.lwz	r8,PT_GPR8(r1)
+
+_syscall_trace_leave:
+	l.jal	do_syscall_trace_leave
+	 l.addi	r3,r1,0
+
+	l.j	_syscall_check_work
+	 l.nop
+
+_syscall_badsys:
+	/* Here we effectively pretend to have executed an imaginary
+	 * syscall that returns -ENOSYS and then return to the regular
+	 * syscall hot path.
+	 * Note that "return value" is set in the delay slot...
+	 */
+	l.j	_syscall_return
+	 l.addi	r11,r0,-ENOSYS
+
+/******* END SYSCALL HANDLING *******/
+
+/* ---[ 0xd00: Trap exception ]------------------------------------------ */
+
+UNHANDLED_EXCEPTION(_vector_0xd00,0xd00)
+
+/* ---[ 0xe00: Trap exception ]------------------------------------------ */
+
+EXCEPTION_ENTRY(_trap_handler)
+	CLEAR_LWA_FLAG(r3)
+	/* r4: EA of fault (set by EXCEPTION_HANDLE) */
+	l.jal   do_trap
+	 l.addi  r3,r1,0 /* pt_regs */
+
+	l.j     _ret_from_exception
+	 l.nop
+
+/* ---[ 0xf00: Reserved exception ]-------------------------------------- */
+
+UNHANDLED_EXCEPTION(_vector_0xf00,0xf00)
+
+/* ---[ 0x1000: Reserved exception ]------------------------------------- */
+
+UNHANDLED_EXCEPTION(_vector_0x1000,0x1000)
+
+/* ---[ 0x1100: Reserved exception ]------------------------------------- */
+
+UNHANDLED_EXCEPTION(_vector_0x1100,0x1100)
+
+/* ---[ 0x1200: Reserved exception ]------------------------------------- */
+
+UNHANDLED_EXCEPTION(_vector_0x1200,0x1200)
+
+/* ---[ 0x1300: Reserved exception ]------------------------------------- */
+
+UNHANDLED_EXCEPTION(_vector_0x1300,0x1300)
+
+/* ---[ 0x1400: Reserved exception ]------------------------------------- */
+
+UNHANDLED_EXCEPTION(_vector_0x1400,0x1400)
+
+/* ---[ 0x1500: Reserved exception ]------------------------------------- */
+
+UNHANDLED_EXCEPTION(_vector_0x1500,0x1500)
+
+/* ---[ 0x1600: Reserved exception ]------------------------------------- */
+
+UNHANDLED_EXCEPTION(_vector_0x1600,0x1600)
+
+/* ---[ 0x1700: Reserved exception ]------------------------------------- */
+
+UNHANDLED_EXCEPTION(_vector_0x1700,0x1700)
+
+/* ---[ 0x1800: Reserved exception ]------------------------------------- */
+
+UNHANDLED_EXCEPTION(_vector_0x1800,0x1800)
+
+/* ---[ 0x1900: Reserved exception ]------------------------------------- */
+
+UNHANDLED_EXCEPTION(_vector_0x1900,0x1900)
+
+/* ---[ 0x1a00: Reserved exception ]------------------------------------- */
+
+UNHANDLED_EXCEPTION(_vector_0x1a00,0x1a00)
+
+/* ---[ 0x1b00: Reserved exception ]------------------------------------- */
+
+UNHANDLED_EXCEPTION(_vector_0x1b00,0x1b00)
+
+/* ---[ 0x1c00: Reserved exception ]------------------------------------- */
+
+UNHANDLED_EXCEPTION(_vector_0x1c00,0x1c00)
+
+/* ---[ 0x1d00: Reserved exception ]------------------------------------- */
+
+UNHANDLED_EXCEPTION(_vector_0x1d00,0x1d00)
+
+/* ---[ 0x1e00: Reserved exception ]------------------------------------- */
+
+UNHANDLED_EXCEPTION(_vector_0x1e00,0x1e00)
+
+/* ---[ 0x1f00: Reserved exception ]------------------------------------- */
+
+UNHANDLED_EXCEPTION(_vector_0x1f00,0x1f00)
+
+/* ========================================================[ return ] === */
+
+_resume_userspace:
+	DISABLE_INTERRUPTS(r3,r4)
+	TRACE_IRQS_OFF
+	l.lwz	r4,TI_FLAGS(r10)
+	l.andi	r13,r4,_TIF_WORK_MASK
+	l.sfeqi	r13,0
+	l.bf	_restore_all
+	 l.nop
+
+_work_pending:
+	l.lwz	r5,PT_ORIG_GPR11(r1)
+	l.sfltsi r5,0
+	l.bnf	1f
+	 l.nop
+	l.andi	r5,r5,0
+1:
+	l.jal	do_work_pending
+	 l.ori	r3,r1,0			/* pt_regs */
+
+	l.sfeqi	r11,0
+	l.bf	_restore_all
+	 l.nop
+	l.sfltsi r11,0
+	l.bnf	1f
+	 l.nop
+	l.and	r11,r11,r0
+	l.ori	r11,r11,__NR_restart_syscall
+	l.j	_syscall_check_trace_enter
+	 l.nop
+1:
+	l.lwz	r11,PT_ORIG_GPR11(r1)
+	/* Restore arg registers */
+	l.lwz	r3,PT_GPR3(r1)
+	l.lwz	r4,PT_GPR4(r1)
+	l.lwz	r5,PT_GPR5(r1)
+	l.lwz	r6,PT_GPR6(r1)
+	l.lwz	r7,PT_GPR7(r1)
+	l.j	_syscall_check_trace_enter
+	 l.lwz	r8,PT_GPR8(r1)
+
+_restore_all:
+#ifdef CONFIG_TRACE_IRQFLAGS
+	l.lwz	r4,PT_SR(r1)
+	l.andi	r3,r4,(SPR_SR_IEE|SPR_SR_TEE)
+	l.sfeq	r3,r0		/* skip trace if irqs were off */
+	l.bf	skip_hardirqs_on
+	 l.nop
+	TRACE_IRQS_ON
+skip_hardirqs_on:
+#endif
+	RESTORE_ALL
+	/* This returns to userspace code */
+
+
+ENTRY(_ret_from_intr)
+ENTRY(_ret_from_exception)
+	l.lwz	r4,PT_SR(r1)
+	l.andi	r3,r4,SPR_SR_SM
+	l.sfeqi	r3,0
+	l.bnf	_restore_all
+	 l.nop
+	l.j	_resume_userspace
+	 l.nop
+
+ENTRY(ret_from_fork)
+	l.jal	schedule_tail
+	 l.nop
+
+	/* Check if we are a kernel thread */
+	l.sfeqi	r20,0
+	l.bf	1f
+	 l.nop
+
+	/* ...we are a kernel thread so invoke the requested callback */
+	l.jalr	r20
+	 l.or	r3,r22,r0
+
+1:
+	/* _syscall_returns expect r11 to contain return value */
+	l.lwz	r11,PT_GPR11(r1)
+
+	/* The syscall fast path return expects call-saved registers
+	 * r12-r28 to be untouched, so we restore them here as they
+	 * will have been effectively clobbered when arriving here
+	 * via the call to switch()
+	 */
+	l.lwz	r12,PT_GPR12(r1)
+	l.lwz	r14,PT_GPR14(r1)
+	l.lwz	r16,PT_GPR16(r1)
+	l.lwz	r18,PT_GPR18(r1)
+	l.lwz	r20,PT_GPR20(r1)
+	l.lwz	r22,PT_GPR22(r1)
+	l.lwz	r24,PT_GPR24(r1)
+	l.lwz	r26,PT_GPR26(r1)
+	l.lwz	r28,PT_GPR28(r1)
+
+	l.j	_syscall_return
+	 l.nop
+
+/* ========================================================[ switch ] === */
+
+/*
+ * This routine switches between two different tasks.  The process
+ * state of one is saved on its kernel stack.  Then the state
+ * of the other is restored from its kernel stack.  The memory
+ * management hardware is updated to the second process's state.
+ * Finally, we can return to the second process, via the 'return'.
+ *
+ * Note: there are two ways to get to the "going out" portion
+ * of this code; either by coming in via the entry (_switch)
+ * or via "fork" which must set up an environment equivalent
+ * to the "_switch" path.  If you change this (or in particular, the
+ * SAVE_REGS macro), you'll have to change the fork code also.
+ */
+
+
+/* _switch MUST never lay on page boundry, cause it runs from
+ * effective addresses and beeing interrupted by iTLB miss would kill it.
+ * dTLB miss seams to never accour in the bad place since data accesses
+ * are from task structures which are always page aligned.
+ *
+ * The problem happens in RESTORE_ALL_NO_R11 where we first set the EPCR
+ * register, then load the previous register values and only at the end call
+ * the l.rfe instruction. If get TLB miss in beetwen the EPCR register gets
+ * garbled and we end up calling l.rfe with the wrong EPCR. (same probably
+ * holds for ESR)
+ *
+ * To avoid this problems it is sufficient to align _switch to
+ * some nice round number smaller than it's size...
+ */
+
+/* ABI rules apply here... we either enter _switch via schedule() or via
+ * an imaginary call to which we shall return at return_from_fork.  Either
+ * way, we are a function call and only need to preserve the callee-saved
+ * registers when we return.  As such, we don't need to save the registers
+ * on the stack that we won't be returning as they were...
+ */
+
+	.align 0x400
+ENTRY(_switch)
+	/* We don't store SR as _switch only gets called in a context where
+	 * the SR will be the same going in and coming out... */
+
+	/* Set up new pt_regs struct for saving task state */
+	l.addi  r1,r1,-(INT_FRAME_SIZE)
+
+	/* No need to store r1/PT_SP as it goes into KSP below */
+	l.sw    PT_GPR2(r1),r2
+	l.sw    PT_GPR9(r1),r9
+	/* This is wrong, r12 shouldn't be here... but GCC is broken for the time being
+	 * and expects r12 to be callee-saved... */
+	l.sw    PT_GPR12(r1),r12
+	l.sw    PT_GPR14(r1),r14
+	l.sw    PT_GPR16(r1),r16
+	l.sw    PT_GPR18(r1),r18
+	l.sw    PT_GPR20(r1),r20
+	l.sw    PT_GPR22(r1),r22
+	l.sw    PT_GPR24(r1),r24
+	l.sw    PT_GPR26(r1),r26
+	l.sw    PT_GPR28(r1),r28
+	l.sw    PT_GPR30(r1),r30
+
+	l.addi	r11,r10,0			/* Save old 'current' to 'last' return value*/
+
+	/* We use thread_info->ksp for storing the address of the above
+	 * structure so that we can get back to it later... we don't want
+	 * to lose the value of thread_info->ksp, though, so store it as
+	 * pt_regs->sp so that we can easily restore it when we are made
+	 * live again...
+	 */
+
+	/* Save the old value of thread_info->ksp as pt_regs->sp */
+	l.lwz	r29,TI_KSP(r10)
+	l.sw	PT_SP(r1),r29
+
+	/* Swap kernel stack pointers */
+	l.sw    TI_KSP(r10),r1			/* Save old stack pointer */
+	l.or	r10,r4,r0			/* Set up new current_thread_info */
+	l.lwz   r1,TI_KSP(r10)			/* Load new stack pointer */
+
+	/* Restore the old value of thread_info->ksp */
+	l.lwz	r29,PT_SP(r1)
+	l.sw	TI_KSP(r10),r29
+
+	/* ...and restore the registers, except r11 because the return value
+	 * has already been set above.
+	 */
+	l.lwz   r2,PT_GPR2(r1)
+	l.lwz   r9,PT_GPR9(r1)
+	/* No need to restore r10 */
+	/* ...and do not restore r11 */
+
+	/* This is wrong, r12 shouldn't be here... but GCC is broken for the time being
+	 * and expects r12 to be callee-saved... */
+	l.lwz   r12,PT_GPR12(r1)
+	l.lwz   r14,PT_GPR14(r1)
+	l.lwz   r16,PT_GPR16(r1)
+	l.lwz   r18,PT_GPR18(r1)
+	l.lwz   r20,PT_GPR20(r1)
+	l.lwz   r22,PT_GPR22(r1)
+	l.lwz   r24,PT_GPR24(r1)
+	l.lwz   r26,PT_GPR26(r1)
+	l.lwz   r28,PT_GPR28(r1)
+	l.lwz   r30,PT_GPR30(r1)
+
+	/* Unwind stack to pre-switch state */
+	l.addi  r1,r1,(INT_FRAME_SIZE)
+
+	/* Return via the link-register back to where we 'came from', where
+	 * that may be either schedule(), ret_from_fork(), or
+	 * ret_from_kernel_thread().  If we are returning to a new thread,
+	 * we are expected to have set up the arg to schedule_tail already,
+	 * hence we do so here unconditionally:
+	 */
+	l.lwz   r3,TI_TASK(r3)		/* Load 'prev' as schedule_tail arg */
+	l.jr	r9
+	 l.nop
+
+/* ==================================================================== */
+
+/* These all use the delay slot for setting the argument register, so the
+ * jump is always happening after the l.addi instruction.
+ *
+ * These are all just wrappers that don't touch the link-register r9, so the
+ * return from the "real" syscall function will return back to the syscall
+ * code that did the l.jal that brought us here.
+ */
+
+/* fork requires that we save all the callee-saved registers because they
+ * are all effectively clobbered by the call to _switch.  Here we store
+ * all the registers that aren't touched by the syscall fast path and thus
+ * weren't saved there.
+ */
+
+_fork_save_extra_regs_and_call:
+	l.sw    PT_GPR14(r1),r14
+	l.sw    PT_GPR16(r1),r16
+	l.sw    PT_GPR18(r1),r18
+	l.sw    PT_GPR20(r1),r20
+	l.sw    PT_GPR22(r1),r22
+	l.sw    PT_GPR24(r1),r24
+	l.sw    PT_GPR26(r1),r26
+	l.jr	r29
+	 l.sw    PT_GPR28(r1),r28
+
+ENTRY(__sys_clone)
+	l.movhi	r29,hi(sys_clone)
+	l.ori	r29,r29,lo(sys_clone)
+	l.j	_fork_save_extra_regs_and_call
+	 l.addi	r7,r1,0
+
+ENTRY(__sys_fork)
+	l.movhi	r29,hi(sys_fork)
+	l.ori	r29,r29,lo(sys_fork)
+	l.j	_fork_save_extra_regs_and_call
+	 l.addi	r3,r1,0
+
+ENTRY(sys_rt_sigreturn)
+	l.jal	_sys_rt_sigreturn
+	 l.addi	r3,r1,0
+	l.sfne	r30,r0
+	l.bnf	_no_syscall_trace
+	 l.nop
+	l.jal	do_syscall_trace_leave
+	 l.addi	r3,r1,0
+_no_syscall_trace:
+	l.j	_resume_userspace
+	 l.nop
+
+/* This is a catch-all syscall for atomic instructions for the OpenRISC 1000.
+ * The functions takes a variable number of parameters depending on which
+ * particular flavour of atomic you want... parameter 1 is a flag identifying
+ * the atomic in question.  Currently, this function implements the
+ * following variants:
+ *
+ * XCHG:
+ *  @flag: 1
+ *  @ptr1:
+ *  @ptr2:
+ * Atomically exchange the values in pointers 1 and 2.
+ *
+ */
+
+ENTRY(sys_or1k_atomic)
+	/* FIXME: This ignores r3 and always does an XCHG */
+	DISABLE_INTERRUPTS(r17,r19)
+	l.lwz	r29,0(r4)
+	l.lwz	r27,0(r5)
+	l.sw	0(r4),r27
+	l.sw	0(r5),r29
+	ENABLE_INTERRUPTS(r17)
+	l.jr	r9
+	 l.or	r11,r0,r0
+
+/* ============================================================[ EOF ]=== */
diff --git a/arch/openrisc/kernel/head.S b/arch/openrisc/kernel/head.S
new file mode 100644
index 0000000..9fc6b60
--- /dev/null
+++ b/arch/openrisc/kernel/head.S
@@ -0,0 +1,1748 @@
+/*
+ * OpenRISC head.S
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/linkage.h>
+#include <linux/threads.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/serial_reg.h>
+#include <asm/processor.h>
+#include <asm/page.h>
+#include <asm/mmu.h>
+#include <asm/pgtable.h>
+#include <asm/thread_info.h>
+#include <asm/cache.h>
+#include <asm/spr_defs.h>
+#include <asm/asm-offsets.h>
+#include <linux/of_fdt.h>
+
+#define tophys(rd,rs)				\
+	l.movhi	rd,hi(-KERNELBASE)		;\
+	l.add	rd,rd,rs
+
+#define CLEAR_GPR(gpr)				\
+	l.movhi	gpr,0x0
+
+#define LOAD_SYMBOL_2_GPR(gpr,symbol)		\
+	l.movhi gpr,hi(symbol)			;\
+	l.ori   gpr,gpr,lo(symbol)
+
+
+#define UART_BASE_ADD      0x90000000
+
+#define EXCEPTION_SR  (SPR_SR_DME | SPR_SR_IME | SPR_SR_DCE | SPR_SR_ICE | SPR_SR_SM)
+#define SYSCALL_SR  (SPR_SR_DME | SPR_SR_IME | SPR_SR_DCE | SPR_SR_ICE | SPR_SR_IEE | SPR_SR_TEE | SPR_SR_SM)
+
+/* ============================================[ tmp store locations ]=== */
+
+#define SPR_SHADOW_GPR(x)	((x) + SPR_GPR_BASE + 32)
+
+/*
+ * emergency_print temporary stores
+ */
+#ifdef CONFIG_OPENRISC_HAVE_SHADOW_GPRS
+#define EMERGENCY_PRINT_STORE_GPR4	l.mtspr r0,r4,SPR_SHADOW_GPR(14)
+#define EMERGENCY_PRINT_LOAD_GPR4	l.mfspr r4,r0,SPR_SHADOW_GPR(14)
+
+#define EMERGENCY_PRINT_STORE_GPR5	l.mtspr r0,r5,SPR_SHADOW_GPR(15)
+#define EMERGENCY_PRINT_LOAD_GPR5	l.mfspr r5,r0,SPR_SHADOW_GPR(15)
+
+#define EMERGENCY_PRINT_STORE_GPR6	l.mtspr r0,r6,SPR_SHADOW_GPR(16)
+#define EMERGENCY_PRINT_LOAD_GPR6	l.mfspr r6,r0,SPR_SHADOW_GPR(16)
+
+#define EMERGENCY_PRINT_STORE_GPR7	l.mtspr r0,r7,SPR_SHADOW_GPR(7)
+#define EMERGENCY_PRINT_LOAD_GPR7	l.mfspr r7,r0,SPR_SHADOW_GPR(7)
+
+#define EMERGENCY_PRINT_STORE_GPR8	l.mtspr r0,r8,SPR_SHADOW_GPR(8)
+#define EMERGENCY_PRINT_LOAD_GPR8	l.mfspr r8,r0,SPR_SHADOW_GPR(8)
+
+#define EMERGENCY_PRINT_STORE_GPR9	l.mtspr r0,r9,SPR_SHADOW_GPR(9)
+#define EMERGENCY_PRINT_LOAD_GPR9	l.mfspr r9,r0,SPR_SHADOW_GPR(9)
+
+#else /* !CONFIG_OPENRISC_HAVE_SHADOW_GPRS */
+#define EMERGENCY_PRINT_STORE_GPR4	l.sw    0x20(r0),r4
+#define EMERGENCY_PRINT_LOAD_GPR4	l.lwz   r4,0x20(r0)
+
+#define EMERGENCY_PRINT_STORE_GPR5	l.sw    0x24(r0),r5
+#define EMERGENCY_PRINT_LOAD_GPR5	l.lwz   r5,0x24(r0)
+
+#define EMERGENCY_PRINT_STORE_GPR6	l.sw    0x28(r0),r6
+#define EMERGENCY_PRINT_LOAD_GPR6	l.lwz   r6,0x28(r0)
+
+#define EMERGENCY_PRINT_STORE_GPR7	l.sw    0x2c(r0),r7
+#define EMERGENCY_PRINT_LOAD_GPR7	l.lwz   r7,0x2c(r0)
+
+#define EMERGENCY_PRINT_STORE_GPR8	l.sw    0x30(r0),r8
+#define EMERGENCY_PRINT_LOAD_GPR8	l.lwz   r8,0x30(r0)
+
+#define EMERGENCY_PRINT_STORE_GPR9	l.sw    0x34(r0),r9
+#define EMERGENCY_PRINT_LOAD_GPR9	l.lwz   r9,0x34(r0)
+
+#endif
+
+/*
+ * TLB miss handlers temorary stores
+ */
+#ifdef CONFIG_OPENRISC_HAVE_SHADOW_GPRS
+#define EXCEPTION_STORE_GPR2		l.mtspr r0,r2,SPR_SHADOW_GPR(2)
+#define EXCEPTION_LOAD_GPR2		l.mfspr r2,r0,SPR_SHADOW_GPR(2)
+
+#define EXCEPTION_STORE_GPR3		l.mtspr r0,r3,SPR_SHADOW_GPR(3)
+#define EXCEPTION_LOAD_GPR3		l.mfspr r3,r0,SPR_SHADOW_GPR(3)
+
+#define EXCEPTION_STORE_GPR4		l.mtspr r0,r4,SPR_SHADOW_GPR(4)
+#define EXCEPTION_LOAD_GPR4		l.mfspr r4,r0,SPR_SHADOW_GPR(4)
+
+#define EXCEPTION_STORE_GPR5		l.mtspr r0,r5,SPR_SHADOW_GPR(5)
+#define EXCEPTION_LOAD_GPR5		l.mfspr r5,r0,SPR_SHADOW_GPR(5)
+
+#define EXCEPTION_STORE_GPR6		l.mtspr r0,r6,SPR_SHADOW_GPR(6)
+#define EXCEPTION_LOAD_GPR6		l.mfspr r6,r0,SPR_SHADOW_GPR(6)
+
+#else /* !CONFIG_OPENRISC_HAVE_SHADOW_GPRS */
+#define EXCEPTION_STORE_GPR2		l.sw    0x64(r0),r2
+#define EXCEPTION_LOAD_GPR2		l.lwz   r2,0x64(r0)
+
+#define EXCEPTION_STORE_GPR3		l.sw    0x68(r0),r3
+#define EXCEPTION_LOAD_GPR3		l.lwz   r3,0x68(r0)
+
+#define EXCEPTION_STORE_GPR4		l.sw    0x6c(r0),r4
+#define EXCEPTION_LOAD_GPR4		l.lwz   r4,0x6c(r0)
+
+#define EXCEPTION_STORE_GPR5		l.sw    0x70(r0),r5
+#define EXCEPTION_LOAD_GPR5		l.lwz   r5,0x70(r0)
+
+#define EXCEPTION_STORE_GPR6		l.sw    0x74(r0),r6
+#define EXCEPTION_LOAD_GPR6		l.lwz   r6,0x74(r0)
+
+#endif
+
+/*
+ * EXCEPTION_HANDLE temporary stores
+ */
+
+#ifdef CONFIG_OPENRISC_HAVE_SHADOW_GPRS
+#define EXCEPTION_T_STORE_GPR30		l.mtspr r0,r30,SPR_SHADOW_GPR(30)
+#define EXCEPTION_T_LOAD_GPR30(reg)	l.mfspr reg,r0,SPR_SHADOW_GPR(30)
+
+#define EXCEPTION_T_STORE_GPR10		l.mtspr r0,r10,SPR_SHADOW_GPR(10)
+#define EXCEPTION_T_LOAD_GPR10(reg)	l.mfspr reg,r0,SPR_SHADOW_GPR(10)
+
+#define EXCEPTION_T_STORE_SP		l.mtspr r0,r1,SPR_SHADOW_GPR(1)
+#define EXCEPTION_T_LOAD_SP(reg)	l.mfspr reg,r0,SPR_SHADOW_GPR(1)
+
+#else /* !CONFIG_OPENRISC_HAVE_SHADOW_GPRS */
+#define EXCEPTION_T_STORE_GPR30		l.sw    0x78(r0),r30
+#define EXCEPTION_T_LOAD_GPR30(reg)	l.lwz   reg,0x78(r0)
+
+#define EXCEPTION_T_STORE_GPR10		l.sw    0x7c(r0),r10
+#define EXCEPTION_T_LOAD_GPR10(reg)	l.lwz   reg,0x7c(r0)
+
+#define EXCEPTION_T_STORE_SP		l.sw    0x80(r0),r1
+#define EXCEPTION_T_LOAD_SP(reg)	l.lwz   reg,0x80(r0)
+#endif
+
+/* =========================================================[ macros ]=== */
+
+#ifdef CONFIG_SMP
+#define GET_CURRENT_PGD(reg,t1)					\
+	LOAD_SYMBOL_2_GPR(reg,current_pgd)			;\
+	l.mfspr	t1,r0,SPR_COREID				;\
+	l.slli	t1,t1,2						;\
+	l.add	reg,reg,t1					;\
+	tophys  (t1,reg)					;\
+	l.lwz   reg,0(t1)
+#else
+#define GET_CURRENT_PGD(reg,t1)					\
+	LOAD_SYMBOL_2_GPR(reg,current_pgd)			;\
+	tophys  (t1,reg)					;\
+	l.lwz   reg,0(t1)
+#endif
+
+/* Load r10 from current_thread_info_set - clobbers r1 and r30 */
+#ifdef CONFIG_SMP
+#define GET_CURRENT_THREAD_INFO					\
+	LOAD_SYMBOL_2_GPR(r1,current_thread_info_set)		;\
+	tophys  (r30,r1)					;\
+	l.mfspr	r10,r0,SPR_COREID				;\
+	l.slli	r10,r10,2					;\
+	l.add	r30,r30,r10					;\
+	/* r10: current_thread_info  */				;\
+	l.lwz   r10,0(r30)
+#else
+#define GET_CURRENT_THREAD_INFO					\
+	LOAD_SYMBOL_2_GPR(r1,current_thread_info_set)		;\
+	tophys  (r30,r1)					;\
+	/* r10: current_thread_info  */				;\
+	l.lwz   r10,0(r30)
+#endif
+
+/*
+ * DSCR: this is a common hook for handling exceptions. it will save
+ *       the needed registers, set up stack and pointer to current
+ *	 then jump to the handler while enabling MMU
+ *
+ * PRMS: handler	- a function to jump to. it has to save the
+ *			remaining registers to kernel stack, call
+ *			appropriate arch-independant exception handler
+ *			and finaly jump to ret_from_except
+ *
+ * PREQ: unchanged state from the time exception happened
+ *
+ * POST: SAVED the following registers original value
+ *	       to the new created exception frame pointed to by r1
+ *
+ *	 r1  - ksp	pointing to the new (exception) frame
+ *	 r4  - EEAR     exception EA
+ *	 r10 - current	pointing to current_thread_info struct
+ *	 r12 - syscall  0, since we didn't come from syscall
+ *	 r30 - handler	address of the handler we'll jump to
+ *
+ *	 handler has to save remaining registers to the exception
+ *	 ksp frame *before* tainting them!
+ *
+ * NOTE: this function is not reentrant per se. reentrancy is guaranteed
+ *       by processor disabling all exceptions/interrupts when exception
+ *	 accours.
+ *
+ * OPTM: no need to make it so wasteful to extract ksp when in user mode
+ */
+
+#define EXCEPTION_HANDLE(handler)				\
+	EXCEPTION_T_STORE_GPR30					;\
+	l.mfspr r30,r0,SPR_ESR_BASE				;\
+	l.andi  r30,r30,SPR_SR_SM				;\
+	l.sfeqi r30,0						;\
+	EXCEPTION_T_STORE_GPR10					;\
+	l.bnf   2f                            /* kernel_mode */	;\
+	 EXCEPTION_T_STORE_SP                 /* delay slot */	;\
+1: /* user_mode:   */						;\
+	GET_CURRENT_THREAD_INFO	 				;\
+	tophys  (r30,r10)					;\
+	l.lwz   r1,(TI_KSP)(r30)				;\
+	/* fall through */					;\
+2: /* kernel_mode: */						;\
+	/* create new stack frame, save only needed gprs */	;\
+	/* r1: KSP, r10: current, r4: EEAR, r31: __pa(KSP) */	;\
+	/* r12:	temp, syscall indicator */			;\
+	l.addi  r1,r1,-(INT_FRAME_SIZE)				;\
+	/* r1 is KSP, r30 is __pa(KSP) */			;\
+	tophys  (r30,r1)					;\
+	l.sw    PT_GPR12(r30),r12				;\
+	/* r4 use for tmp before EA */				;\
+	l.mfspr r12,r0,SPR_EPCR_BASE				;\
+	l.sw    PT_PC(r30),r12					;\
+	l.mfspr r12,r0,SPR_ESR_BASE				;\
+	l.sw    PT_SR(r30),r12					;\
+	/* save r30 */						;\
+	EXCEPTION_T_LOAD_GPR30(r12)				;\
+	l.sw	PT_GPR30(r30),r12				;\
+	/* save r10 as was prior to exception */		;\
+	EXCEPTION_T_LOAD_GPR10(r12)				;\
+	l.sw	PT_GPR10(r30),r12				;\
+	/* save PT_SP as was prior to exception */		;\
+	EXCEPTION_T_LOAD_SP(r12)				;\
+	l.sw	PT_SP(r30),r12					;\
+	/* save exception r4, set r4 = EA */			;\
+	l.sw	PT_GPR4(r30),r4					;\
+	l.mfspr r4,r0,SPR_EEAR_BASE				;\
+	/* r12 == 1 if we come from syscall */			;\
+	CLEAR_GPR(r12)						;\
+	/* ----- turn on MMU ----- */				;\
+	/* Carry DSX into exception SR */			;\
+	l.mfspr r30,r0,SPR_SR					;\
+	l.andi	r30,r30,SPR_SR_DSX				;\
+	l.ori	r30,r30,(EXCEPTION_SR)				;\
+	l.mtspr	r0,r30,SPR_ESR_BASE				;\
+	/* r30:	EA address of handler */			;\
+	LOAD_SYMBOL_2_GPR(r30,handler)				;\
+	l.mtspr r0,r30,SPR_EPCR_BASE				;\
+	l.rfe
+
+/*
+ * this doesn't work
+ *
+ *
+ * #ifdef CONFIG_JUMP_UPON_UNHANDLED_EXCEPTION
+ * #define UNHANDLED_EXCEPTION(handler)				\
+ *	l.ori   r3,r0,0x1					;\
+ *	l.mtspr r0,r3,SPR_SR					;\
+ *      l.movhi r3,hi(0xf0000100)				;\
+ *      l.ori   r3,r3,lo(0xf0000100)				;\
+ *	l.jr	r3						;\
+ *	l.nop	1
+ *
+ * #endif
+ */
+
+/* DSCR: this is the same as EXCEPTION_HANDLE(), we are just
+ *       a bit more carefull (if we have a PT_SP or current pointer
+ *       corruption) and set them up from 'current_set'
+ *
+ */
+#define UNHANDLED_EXCEPTION(handler)				\
+	EXCEPTION_T_STORE_GPR30					;\
+	EXCEPTION_T_STORE_GPR10					;\
+	EXCEPTION_T_STORE_SP					;\
+	/* temporary store r3, r9 into r1, r10 */		;\
+	l.addi	r1,r3,0x0					;\
+	l.addi	r10,r9,0x0					;\
+	/* the string referenced by r3 must be low enough */	;\
+	l.jal	_emergency_print				;\
+	l.ori	r3,r0,lo(_string_unhandled_exception)		;\
+	l.mfspr	r3,r0,SPR_NPC					;\
+	l.jal	_emergency_print_nr				;\
+	l.andi	r3,r3,0x1f00					;\
+	/* the string referenced by r3 must be low enough */	;\
+	l.jal	_emergency_print				;\
+	l.ori	r3,r0,lo(_string_epc_prefix)			;\
+	l.jal	_emergency_print_nr				;\
+	l.mfspr	r3,r0,SPR_EPCR_BASE				;\
+	l.jal	_emergency_print				;\
+	l.ori	r3,r0,lo(_string_nl)				;\
+	/* end of printing */					;\
+	l.addi	r3,r1,0x0					;\
+	l.addi	r9,r10,0x0					;\
+	/* extract current, ksp from current_set */		;\
+	LOAD_SYMBOL_2_GPR(r1,_unhandled_stack_top)		;\
+	LOAD_SYMBOL_2_GPR(r10,init_thread_union)		;\
+	/* create new stack frame, save only needed gprs */	;\
+	/* r1: KSP, r10: current, r31: __pa(KSP) */		;\
+	/* r12:	temp, syscall indicator, r13 temp */		;\
+	l.addi  r1,r1,-(INT_FRAME_SIZE)				;\
+	/* r1 is KSP, r30 is __pa(KSP) */			;\
+	tophys  (r30,r1)					;\
+	l.sw    PT_GPR12(r30),r12					;\
+	l.mfspr r12,r0,SPR_EPCR_BASE				;\
+	l.sw    PT_PC(r30),r12					;\
+	l.mfspr r12,r0,SPR_ESR_BASE				;\
+	l.sw    PT_SR(r30),r12					;\
+	/* save r31 */						;\
+	EXCEPTION_T_LOAD_GPR30(r12)				;\
+	l.sw	PT_GPR30(r30),r12					;\
+	/* save r10 as was prior to exception */		;\
+	EXCEPTION_T_LOAD_GPR10(r12)				;\
+	l.sw	PT_GPR10(r30),r12					;\
+	/* save PT_SP as was prior to exception */			;\
+	EXCEPTION_T_LOAD_SP(r12)				;\
+	l.sw	PT_SP(r30),r12					;\
+	l.sw    PT_GPR13(r30),r13					;\
+	/* --> */						;\
+	/* save exception r4, set r4 = EA */			;\
+	l.sw	PT_GPR4(r30),r4					;\
+	l.mfspr r4,r0,SPR_EEAR_BASE				;\
+	/* r12 == 1 if we come from syscall */			;\
+	CLEAR_GPR(r12)						;\
+	/* ----- play a MMU trick ----- */			;\
+	l.ori	r30,r0,(EXCEPTION_SR)				;\
+	l.mtspr	r0,r30,SPR_ESR_BASE				;\
+	/* r31:	EA address of handler */			;\
+	LOAD_SYMBOL_2_GPR(r30,handler)				;\
+	l.mtspr r0,r30,SPR_EPCR_BASE				;\
+	l.rfe
+
+/* =====================================================[ exceptions] === */
+
+/* ---[ 0x100: RESET exception ]----------------------------------------- */
+    .org 0x100
+	/* Jump to .init code at _start which lives in the .head section
+	 * and will be discarded after boot.
+	 */
+	LOAD_SYMBOL_2_GPR(r15, _start)
+	tophys	(r13,r15)			/* MMU disabled */
+	l.jr	r13
+	 l.nop
+
+/* ---[ 0x200: BUS exception ]------------------------------------------- */
+    .org 0x200
+_dispatch_bus_fault:
+	EXCEPTION_HANDLE(_bus_fault_handler)
+
+/* ---[ 0x300: Data Page Fault exception ]------------------------------- */
+    .org 0x300
+_dispatch_do_dpage_fault:
+//      totaly disable timer interrupt
+// 	l.mtspr	r0,r0,SPR_TTMR
+//	DEBUG_TLB_PROBE(0x300)
+//	EXCEPTION_DEBUG_VALUE_ER_ENABLED(0x300)
+	EXCEPTION_HANDLE(_data_page_fault_handler)
+
+/* ---[ 0x400: Insn Page Fault exception ]------------------------------- */
+    .org 0x400
+_dispatch_do_ipage_fault:
+//      totaly disable timer interrupt
+//	l.mtspr	r0,r0,SPR_TTMR
+//	DEBUG_TLB_PROBE(0x400)
+//	EXCEPTION_DEBUG_VALUE_ER_ENABLED(0x400)
+	EXCEPTION_HANDLE(_insn_page_fault_handler)
+
+/* ---[ 0x500: Timer exception ]----------------------------------------- */
+    .org 0x500
+	EXCEPTION_HANDLE(_timer_handler)
+
+/* ---[ 0x600: Alignment exception ]-------------------------------------- */
+    .org 0x600
+	EXCEPTION_HANDLE(_alignment_handler)
+
+/* ---[ 0x700: Illegal insn exception ]---------------------------------- */
+    .org 0x700
+	EXCEPTION_HANDLE(_illegal_instruction_handler)
+
+/* ---[ 0x800: External interrupt exception ]---------------------------- */
+    .org 0x800
+	EXCEPTION_HANDLE(_external_irq_handler)
+
+/* ---[ 0x900: DTLB miss exception ]------------------------------------- */
+    .org 0x900
+	l.j	boot_dtlb_miss_handler
+	l.nop
+
+/* ---[ 0xa00: ITLB miss exception ]------------------------------------- */
+    .org 0xa00
+	l.j	boot_itlb_miss_handler
+	l.nop
+
+/* ---[ 0xb00: Range exception ]----------------------------------------- */
+    .org 0xb00
+	UNHANDLED_EXCEPTION(_vector_0xb00)
+
+/* ---[ 0xc00: Syscall exception ]--------------------------------------- */
+    .org 0xc00
+	EXCEPTION_HANDLE(_sys_call_handler)
+
+/* ---[ 0xd00: Trap exception ]------------------------------------------ */
+    .org 0xd00
+	UNHANDLED_EXCEPTION(_vector_0xd00)
+
+/* ---[ 0xe00: Trap exception ]------------------------------------------ */
+    .org 0xe00
+//	UNHANDLED_EXCEPTION(_vector_0xe00)
+	EXCEPTION_HANDLE(_trap_handler)
+
+/* ---[ 0xf00: Reserved exception ]-------------------------------------- */
+    .org 0xf00
+	UNHANDLED_EXCEPTION(_vector_0xf00)
+
+/* ---[ 0x1000: Reserved exception ]------------------------------------- */
+    .org 0x1000
+	UNHANDLED_EXCEPTION(_vector_0x1000)
+
+/* ---[ 0x1100: Reserved exception ]------------------------------------- */
+    .org 0x1100
+	UNHANDLED_EXCEPTION(_vector_0x1100)
+
+/* ---[ 0x1200: Reserved exception ]------------------------------------- */
+    .org 0x1200
+	UNHANDLED_EXCEPTION(_vector_0x1200)
+
+/* ---[ 0x1300: Reserved exception ]------------------------------------- */
+    .org 0x1300
+	UNHANDLED_EXCEPTION(_vector_0x1300)
+
+/* ---[ 0x1400: Reserved exception ]------------------------------------- */
+    .org 0x1400
+	UNHANDLED_EXCEPTION(_vector_0x1400)
+
+/* ---[ 0x1500: Reserved exception ]------------------------------------- */
+    .org 0x1500
+	UNHANDLED_EXCEPTION(_vector_0x1500)
+
+/* ---[ 0x1600: Reserved exception ]------------------------------------- */
+    .org 0x1600
+	UNHANDLED_EXCEPTION(_vector_0x1600)
+
+/* ---[ 0x1700: Reserved exception ]------------------------------------- */
+    .org 0x1700
+	UNHANDLED_EXCEPTION(_vector_0x1700)
+
+/* ---[ 0x1800: Reserved exception ]------------------------------------- */
+    .org 0x1800
+	UNHANDLED_EXCEPTION(_vector_0x1800)
+
+/* ---[ 0x1900: Reserved exception ]------------------------------------- */
+    .org 0x1900
+	UNHANDLED_EXCEPTION(_vector_0x1900)
+
+/* ---[ 0x1a00: Reserved exception ]------------------------------------- */
+    .org 0x1a00
+	UNHANDLED_EXCEPTION(_vector_0x1a00)
+
+/* ---[ 0x1b00: Reserved exception ]------------------------------------- */
+    .org 0x1b00
+	UNHANDLED_EXCEPTION(_vector_0x1b00)
+
+/* ---[ 0x1c00: Reserved exception ]------------------------------------- */
+    .org 0x1c00
+	UNHANDLED_EXCEPTION(_vector_0x1c00)
+
+/* ---[ 0x1d00: Reserved exception ]------------------------------------- */
+    .org 0x1d00
+	UNHANDLED_EXCEPTION(_vector_0x1d00)
+
+/* ---[ 0x1e00: Reserved exception ]------------------------------------- */
+    .org 0x1e00
+	UNHANDLED_EXCEPTION(_vector_0x1e00)
+
+/* ---[ 0x1f00: Reserved exception ]------------------------------------- */
+    .org 0x1f00
+	UNHANDLED_EXCEPTION(_vector_0x1f00)
+
+    .org 0x2000
+/* ===================================================[ kernel start ]=== */
+
+/*    .text*/
+
+/* This early stuff belongs in HEAD, but some of the functions below definitely
+ * don't... */
+
+	__HEAD
+	.global _start
+_start:
+	/* Init r0 to zero as per spec */
+	CLEAR_GPR(r0)
+
+	/* save kernel parameters */
+	l.or	r25,r0,r3	/* pointer to fdt */
+
+	/*
+	 * ensure a deterministic start
+	 */
+
+	l.ori	r3,r0,0x1
+	l.mtspr	r0,r3,SPR_SR
+
+	CLEAR_GPR(r1)
+	CLEAR_GPR(r2)
+	CLEAR_GPR(r3)
+	CLEAR_GPR(r4)
+	CLEAR_GPR(r5)
+	CLEAR_GPR(r6)
+	CLEAR_GPR(r7)
+	CLEAR_GPR(r8)
+	CLEAR_GPR(r9)
+	CLEAR_GPR(r10)
+	CLEAR_GPR(r11)
+	CLEAR_GPR(r12)
+	CLEAR_GPR(r13)
+	CLEAR_GPR(r14)
+	CLEAR_GPR(r15)
+	CLEAR_GPR(r16)
+	CLEAR_GPR(r17)
+	CLEAR_GPR(r18)
+	CLEAR_GPR(r19)
+	CLEAR_GPR(r20)
+	CLEAR_GPR(r21)
+	CLEAR_GPR(r22)
+	CLEAR_GPR(r23)
+	CLEAR_GPR(r24)
+	CLEAR_GPR(r26)
+	CLEAR_GPR(r27)
+	CLEAR_GPR(r28)
+	CLEAR_GPR(r29)
+	CLEAR_GPR(r30)
+	CLEAR_GPR(r31)
+
+#ifdef CONFIG_SMP
+	l.mfspr	r26,r0,SPR_COREID
+	l.sfeq	r26,r0
+	l.bnf	secondary_wait
+	 l.nop
+#endif
+	/*
+	 * set up initial ksp and current
+	 */
+	/* setup kernel stack */
+	LOAD_SYMBOL_2_GPR(r1,init_thread_union + THREAD_SIZE)
+	LOAD_SYMBOL_2_GPR(r10,init_thread_union)	// setup current
+	tophys	(r31,r10)
+	l.sw	TI_KSP(r31), r1
+
+	l.ori	r4,r0,0x0
+
+
+	/*
+	 * .data contains initialized data,
+	 * .bss contains uninitialized data - clear it up
+	 */
+clear_bss:
+	LOAD_SYMBOL_2_GPR(r24, __bss_start)
+	LOAD_SYMBOL_2_GPR(r26, _end)
+	tophys(r28,r24)
+	tophys(r30,r26)
+	CLEAR_GPR(r24)
+	CLEAR_GPR(r26)
+1:
+	l.sw    (0)(r28),r0
+	l.sfltu r28,r30
+	l.bf    1b
+	l.addi  r28,r28,4
+
+enable_ic:
+	l.jal	_ic_enable
+	 l.nop
+
+enable_dc:
+	l.jal	_dc_enable
+	 l.nop
+
+flush_tlb:
+	l.jal	_flush_tlb
+	 l.nop
+
+/* The MMU needs to be enabled before or32_early_setup is called */
+
+enable_mmu:
+	/*
+	 * enable dmmu & immu
+	 * SR[5] = 0, SR[6] = 0, 6th and 7th bit of SR set to 0
+	 */
+	l.mfspr	r30,r0,SPR_SR
+	l.movhi	r28,hi(SPR_SR_DME | SPR_SR_IME)
+	l.ori	r28,r28,lo(SPR_SR_DME | SPR_SR_IME)
+	l.or	r30,r30,r28
+	l.mtspr	r0,r30,SPR_SR
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+
+	// reset the simulation counters
+	l.nop 5
+
+	/* check fdt header magic word */
+	l.lwz	r3,0(r25)	/* load magic from fdt into r3 */
+	l.movhi	r4,hi(OF_DT_HEADER)
+	l.ori	r4,r4,lo(OF_DT_HEADER)
+	l.sfeq	r3,r4
+	l.bf	_fdt_found
+	 l.nop
+	/* magic number mismatch, set fdt pointer to null */
+	l.or	r25,r0,r0
+_fdt_found:
+	/* pass fdt pointer to or32_early_setup in r3 */
+	l.or	r3,r0,r25
+	LOAD_SYMBOL_2_GPR(r24, or32_early_setup)
+	l.jalr r24
+	 l.nop
+
+clear_regs:
+	/*
+	 * clear all GPRS to increase determinism
+	 */
+	CLEAR_GPR(r2)
+	CLEAR_GPR(r3)
+	CLEAR_GPR(r4)
+	CLEAR_GPR(r5)
+	CLEAR_GPR(r6)
+	CLEAR_GPR(r7)
+	CLEAR_GPR(r8)
+	CLEAR_GPR(r9)
+	CLEAR_GPR(r11)
+	CLEAR_GPR(r12)
+	CLEAR_GPR(r13)
+	CLEAR_GPR(r14)
+	CLEAR_GPR(r15)
+	CLEAR_GPR(r16)
+	CLEAR_GPR(r17)
+	CLEAR_GPR(r18)
+	CLEAR_GPR(r19)
+	CLEAR_GPR(r20)
+	CLEAR_GPR(r21)
+	CLEAR_GPR(r22)
+	CLEAR_GPR(r23)
+	CLEAR_GPR(r24)
+	CLEAR_GPR(r25)
+	CLEAR_GPR(r26)
+	CLEAR_GPR(r27)
+	CLEAR_GPR(r28)
+	CLEAR_GPR(r29)
+	CLEAR_GPR(r30)
+	CLEAR_GPR(r31)
+
+jump_start_kernel:
+	/*
+	 * jump to kernel entry (start_kernel)
+	 */
+	LOAD_SYMBOL_2_GPR(r30, start_kernel)
+	l.jr    r30
+	 l.nop
+
+_flush_tlb:
+	/*
+	 *  I N V A L I D A T E   T L B   e n t r i e s
+	 */
+	LOAD_SYMBOL_2_GPR(r5,SPR_DTLBMR_BASE(0))
+	LOAD_SYMBOL_2_GPR(r6,SPR_ITLBMR_BASE(0))
+	l.addi	r7,r0,128 /* Maximum number of sets */
+1:
+	l.mtspr	r5,r0,0x0
+	l.mtspr	r6,r0,0x0
+
+	l.addi	r5,r5,1
+	l.addi	r6,r6,1
+	l.sfeq	r7,r0
+	l.bnf	1b
+	 l.addi	r7,r7,-1
+
+	l.jr	r9
+	 l.nop
+
+#ifdef CONFIG_SMP
+secondary_wait:
+	/* Doze the cpu until we are asked to run */
+	/* If we dont have power management skip doze */
+	l.mfspr r25,r0,SPR_UPR
+	l.andi  r25,r25,SPR_UPR_PMP
+	l.sfeq  r25,r0
+	l.bf	secondary_check_release
+	 l.nop
+
+	/* Setup special secondary exception handler */
+	LOAD_SYMBOL_2_GPR(r3, _secondary_evbar)
+	tophys(r25,r3)
+	l.mtspr	r0,r25,SPR_EVBAR
+
+	/* Enable Interrupts */
+	l.mfspr	r25,r0,SPR_SR
+	l.ori	r25,r25,SPR_SR_IEE
+	l.mtspr	r0,r25,SPR_SR
+
+	/* Unmask interrupts interrupts */
+	l.mfspr r25,r0,SPR_PICMR
+	l.ori   r25,r25,0xffff
+	l.mtspr	r0,r25,SPR_PICMR
+
+	/* Doze */
+	l.mfspr r25,r0,SPR_PMR
+	LOAD_SYMBOL_2_GPR(r3, SPR_PMR_DME)
+	l.or    r25,r25,r3
+	l.mtspr r0,r25,SPR_PMR
+
+	/* Wakeup - Restore exception handler */
+	l.mtspr	r0,r0,SPR_EVBAR
+
+secondary_check_release:
+	/*
+	 * Check if we actually got the release signal, if not go-back to
+	 * sleep.
+	 */
+	l.mfspr	r25,r0,SPR_COREID
+	LOAD_SYMBOL_2_GPR(r3, secondary_release)
+	tophys(r4, r3)
+	l.lwz	r3,0(r4)
+	l.sfeq	r25,r3
+	l.bnf	secondary_wait
+	 l.nop
+	/* fall through to secondary_init */
+
+secondary_init:
+	/*
+	 * set up initial ksp and current
+	 */
+	LOAD_SYMBOL_2_GPR(r10, secondary_thread_info)
+	tophys	(r30,r10)
+	l.lwz	r10,0(r30)
+	l.addi	r1,r10,THREAD_SIZE
+	tophys	(r30,r10)
+	l.sw	TI_KSP(r30),r1
+
+	l.jal	_ic_enable
+	 l.nop
+
+	l.jal	_dc_enable
+	 l.nop
+
+	l.jal	_flush_tlb
+	 l.nop
+
+	/*
+	 * enable dmmu & immu
+	 */
+	l.mfspr	r30,r0,SPR_SR
+	l.movhi	r28,hi(SPR_SR_DME | SPR_SR_IME)
+	l.ori	r28,r28,lo(SPR_SR_DME | SPR_SR_IME)
+	l.or	r30,r30,r28
+	/*
+	 * This is a bit tricky, we need to switch over from physical addresses
+	 * to virtual addresses on the fly.
+	 * To do that, we first set up ESR with the IME and DME bits set.
+	 * Then EPCR is set to secondary_start and then a l.rfe is issued to
+	 * "jump" to that.
+	 */
+	l.mtspr	r0,r30,SPR_ESR_BASE
+	LOAD_SYMBOL_2_GPR(r30, secondary_start)
+	l.mtspr	r0,r30,SPR_EPCR_BASE
+	l.rfe
+
+secondary_start:
+	LOAD_SYMBOL_2_GPR(r30, secondary_start_kernel)
+	l.jr    r30
+	 l.nop
+
+#endif
+
+/* ========================================[ cache ]=== */
+
+	/* alignment here so we don't change memory offsets with
+	 * memory controller defined
+	 */
+	.align 0x2000
+
+_ic_enable:
+	/* Check if IC present and skip enabling otherwise */
+	l.mfspr r24,r0,SPR_UPR
+	l.andi  r26,r24,SPR_UPR_ICP
+	l.sfeq  r26,r0
+	l.bf	9f
+	l.nop
+
+	/* Disable IC */
+	l.mfspr r6,r0,SPR_SR
+	l.addi  r5,r0,-1
+	l.xori  r5,r5,SPR_SR_ICE
+	l.and   r5,r6,r5
+	l.mtspr r0,r5,SPR_SR
+
+	/* Establish cache block size
+	   If BS=0, 16;
+	   If BS=1, 32;
+	   r14 contain block size
+	*/
+	l.mfspr r24,r0,SPR_ICCFGR
+	l.andi	r26,r24,SPR_ICCFGR_CBS
+	l.srli	r28,r26,7
+	l.ori	r30,r0,16
+	l.sll	r14,r30,r28
+
+	/* Establish number of cache sets
+	   r16 contains number of cache sets
+	   r28 contains log(# of cache sets)
+	*/
+	l.andi  r26,r24,SPR_ICCFGR_NCS
+	l.srli 	r28,r26,3
+	l.ori   r30,r0,1
+	l.sll   r16,r30,r28
+
+	/* Invalidate IC */
+	l.addi  r6,r0,0
+	l.sll   r5,r14,r28
+//        l.mul   r5,r14,r16
+//	l.trap  1
+//	l.addi  r5,r0,IC_SIZE
+1:
+	l.mtspr r0,r6,SPR_ICBIR
+	l.sfne  r6,r5
+	l.bf    1b
+	l.add   r6,r6,r14
+ //       l.addi   r6,r6,IC_LINE
+
+	/* Enable IC */
+	l.mfspr r6,r0,SPR_SR
+	l.ori   r6,r6,SPR_SR_ICE
+	l.mtspr r0,r6,SPR_SR
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+	l.nop
+9:
+	l.jr    r9
+	l.nop
+
+_dc_enable:
+	/* Check if DC present and skip enabling otherwise */
+	l.mfspr r24,r0,SPR_UPR
+	l.andi  r26,r24,SPR_UPR_DCP
+	l.sfeq  r26,r0
+	l.bf	9f
+	l.nop
+
+	/* Disable DC */
+	l.mfspr r6,r0,SPR_SR
+	l.addi  r5,r0,-1
+	l.xori  r5,r5,SPR_SR_DCE
+	l.and   r5,r6,r5
+	l.mtspr r0,r5,SPR_SR
+
+	/* Establish cache block size
+	   If BS=0, 16;
+	   If BS=1, 32;
+	   r14 contain block size
+	*/
+	l.mfspr r24,r0,SPR_DCCFGR
+	l.andi	r26,r24,SPR_DCCFGR_CBS
+	l.srli	r28,r26,7
+	l.ori	r30,r0,16
+	l.sll	r14,r30,r28
+
+	/* Establish number of cache sets
+	   r16 contains number of cache sets
+	   r28 contains log(# of cache sets)
+	*/
+	l.andi  r26,r24,SPR_DCCFGR_NCS
+	l.srli 	r28,r26,3
+	l.ori   r30,r0,1
+	l.sll   r16,r30,r28
+
+	/* Invalidate DC */
+	l.addi  r6,r0,0
+	l.sll   r5,r14,r28
+1:
+	l.mtspr r0,r6,SPR_DCBIR
+	l.sfne  r6,r5
+	l.bf    1b
+	l.add   r6,r6,r14
+
+	/* Enable DC */
+	l.mfspr r6,r0,SPR_SR
+	l.ori   r6,r6,SPR_SR_DCE
+	l.mtspr r0,r6,SPR_SR
+9:
+	l.jr    r9
+	l.nop
+
+/* ===============================================[ page table masks ]=== */
+
+#define DTLB_UP_CONVERT_MASK  0x3fa
+#define ITLB_UP_CONVERT_MASK  0x3a
+
+/* for SMP we'd have (this is a bit subtle, CC must be always set
+ * for SMP, but since we have _PAGE_PRESENT bit always defined
+ * we can just modify the mask)
+ */
+#define DTLB_SMP_CONVERT_MASK  0x3fb
+#define ITLB_SMP_CONVERT_MASK  0x3b
+
+/* ---[ boot dtlb miss handler ]----------------------------------------- */
+
+boot_dtlb_miss_handler:
+
+/* mask for DTLB_MR register: - (0) sets V (valid) bit,
+ *                            - (31-12) sets bits belonging to VPN (31-12)
+ */
+#define DTLB_MR_MASK 0xfffff001
+
+/* mask for DTLB_TR register: - (2) sets CI (cache inhibit) bit,
+ *			      - (4) sets A (access) bit,
+ *                            - (5) sets D (dirty) bit,
+ *                            - (8) sets SRE (superuser read) bit
+ *                            - (9) sets SWE (superuser write) bit
+ *                            - (31-12) sets bits belonging to VPN (31-12)
+ */
+#define DTLB_TR_MASK 0xfffff332
+
+/* These are for masking out the VPN/PPN value from the MR/TR registers...
+ * it's not the same as the PFN */
+#define VPN_MASK 0xfffff000
+#define PPN_MASK 0xfffff000
+
+
+	EXCEPTION_STORE_GPR6
+
+#if 0
+	l.mfspr r6,r0,SPR_ESR_BASE	   //
+	l.andi  r6,r6,SPR_SR_SM            // are we in kernel mode ?
+	l.sfeqi r6,0                       // r6 == 0x1 --> SM
+	l.bf    exit_with_no_dtranslation  //
+	l.nop
+#endif
+
+	/* this could be optimized by moving storing of
+	 * non r6 registers here, and jumping r6 restore
+	 * if not in supervisor mode
+	 */
+
+	EXCEPTION_STORE_GPR2
+	EXCEPTION_STORE_GPR3
+	EXCEPTION_STORE_GPR4
+	EXCEPTION_STORE_GPR5
+
+	l.mfspr r4,r0,SPR_EEAR_BASE        // get the offending EA
+
+immediate_translation:
+	CLEAR_GPR(r6)
+
+	l.srli	r3,r4,0xd                  // r3 <- r4 / 8192 (sets are relative to page size (8Kb) NOT VPN size (4Kb)
+
+	l.mfspr r6, r0, SPR_DMMUCFGR
+	l.andi	r6, r6, SPR_DMMUCFGR_NTS
+	l.srli	r6, r6, SPR_DMMUCFGR_NTS_OFF
+	l.ori	r5, r0, 0x1
+	l.sll	r5, r5, r6 	// r5 = number DMMU sets
+	l.addi	r6, r5, -1  	// r6 = nsets mask
+	l.and	r2, r3, r6	// r2 <- r3 % NSETS_MASK
+
+	l.or    r6,r6,r4                   // r6 <- r4
+	l.ori   r6,r6,~(VPN_MASK)          // r6 <- VPN :VPN .xfff - clear up lo(r6) to 0x**** *fff
+	l.movhi r5,hi(DTLB_MR_MASK)        // r5 <- ffff:0000.x000
+	l.ori   r5,r5,lo(DTLB_MR_MASK)     // r5 <- ffff:1111.x001 - apply DTLB_MR_MASK
+	l.and   r5,r5,r6                   // r5 <- VPN :VPN .x001 - we have DTLBMR entry
+	l.mtspr r2,r5,SPR_DTLBMR_BASE(0)   // set DTLBMR
+
+	/* set up DTLB with no translation for EA <= 0xbfffffff */
+	LOAD_SYMBOL_2_GPR(r6,0xbfffffff)
+	l.sfgeu  r6,r4                     // flag if r6 >= r4 (if 0xbfffffff >= EA)
+	l.bf     1f                        // goto out
+	l.and    r3,r4,r4                  // delay slot :: 24 <- r4 (if flag==1)
+
+	tophys(r3,r4)                      // r3 <- PA
+1:
+	l.ori   r3,r3,~(PPN_MASK)          // r3 <- PPN :PPN .xfff - clear up lo(r6) to 0x**** *fff
+	l.movhi r5,hi(DTLB_TR_MASK)        // r5 <- ffff:0000.x000
+	l.ori   r5,r5,lo(DTLB_TR_MASK)     // r5 <- ffff:1111.x330 - apply DTLB_MR_MASK
+	l.and   r5,r5,r3                   // r5 <- PPN :PPN .x330 - we have DTLBTR entry
+	l.mtspr r2,r5,SPR_DTLBTR_BASE(0)   // set DTLBTR
+
+	EXCEPTION_LOAD_GPR6
+	EXCEPTION_LOAD_GPR5
+	EXCEPTION_LOAD_GPR4
+	EXCEPTION_LOAD_GPR3
+	EXCEPTION_LOAD_GPR2
+
+	l.rfe                              // SR <- ESR, PC <- EPC
+
+exit_with_no_dtranslation:
+	/* EA out of memory or not in supervisor mode */
+	EXCEPTION_LOAD_GPR6
+	EXCEPTION_LOAD_GPR4
+	l.j	_dispatch_bus_fault
+
+/* ---[ boot itlb miss handler ]----------------------------------------- */
+
+boot_itlb_miss_handler:
+
+/* mask for ITLB_MR register: - sets V (valid) bit,
+ *                            - sets bits belonging to VPN (15-12)
+ */
+#define ITLB_MR_MASK 0xfffff001
+
+/* mask for ITLB_TR register: - sets A (access) bit,
+ *                            - sets SXE (superuser execute) bit
+ *                            - sets bits belonging to VPN (15-12)
+ */
+#define ITLB_TR_MASK 0xfffff050
+
+/*
+#define VPN_MASK 0xffffe000
+#define PPN_MASK 0xffffe000
+*/
+
+
+
+	EXCEPTION_STORE_GPR2
+	EXCEPTION_STORE_GPR3
+	EXCEPTION_STORE_GPR4
+	EXCEPTION_STORE_GPR5
+	EXCEPTION_STORE_GPR6
+
+#if 0
+	l.mfspr r6,r0,SPR_ESR_BASE         //
+	l.andi  r6,r6,SPR_SR_SM            // are we in kernel mode ?
+	l.sfeqi r6,0                       // r6 == 0x1 --> SM
+	l.bf    exit_with_no_itranslation
+	l.nop
+#endif
+
+
+	l.mfspr r4,r0,SPR_EEAR_BASE        // get the offending EA
+
+earlyearly:
+	CLEAR_GPR(r6)
+
+	l.srli  r3,r4,0xd                  // r3 <- r4 / 8192 (sets are relative to page size (8Kb) NOT VPN size (4Kb)
+
+	l.mfspr r6, r0, SPR_IMMUCFGR
+	l.andi	r6, r6, SPR_IMMUCFGR_NTS
+	l.srli	r6, r6, SPR_IMMUCFGR_NTS_OFF
+	l.ori	r5, r0, 0x1
+	l.sll	r5, r5, r6 	// r5 = number IMMU sets from IMMUCFGR
+	l.addi	r6, r5, -1  	// r6 = nsets mask
+	l.and	r2, r3, r6	// r2 <- r3 % NSETS_MASK
+
+	l.or    r6,r6,r4                   // r6 <- r4
+	l.ori   r6,r6,~(VPN_MASK)          // r6 <- VPN :VPN .xfff - clear up lo(r6) to 0x**** *fff
+	l.movhi r5,hi(ITLB_MR_MASK)        // r5 <- ffff:0000.x000
+	l.ori   r5,r5,lo(ITLB_MR_MASK)     // r5 <- ffff:1111.x001 - apply ITLB_MR_MASK
+	l.and   r5,r5,r6                   // r5 <- VPN :VPN .x001 - we have ITLBMR entry
+	l.mtspr r2,r5,SPR_ITLBMR_BASE(0)   // set ITLBMR
+
+	/*
+	 * set up ITLB with no translation for EA <= 0x0fffffff
+	 *
+	 * we need this for head.S mapping (EA = PA). if we move all functions
+	 * which run with mmu enabled into entry.S, we might be able to eliminate this.
+	 *
+	 */
+	LOAD_SYMBOL_2_GPR(r6,0x0fffffff)
+	l.sfgeu  r6,r4                     // flag if r6 >= r4 (if 0xb0ffffff >= EA)
+	l.bf     1f                        // goto out
+	l.and    r3,r4,r4                  // delay slot :: 24 <- r4 (if flag==1)
+
+	tophys(r3,r4)                      // r3 <- PA
+1:
+	l.ori   r3,r3,~(PPN_MASK)          // r3 <- PPN :PPN .xfff - clear up lo(r6) to 0x**** *fff
+	l.movhi r5,hi(ITLB_TR_MASK)        // r5 <- ffff:0000.x000
+	l.ori   r5,r5,lo(ITLB_TR_MASK)     // r5 <- ffff:1111.x050 - apply ITLB_MR_MASK
+	l.and   r5,r5,r3                   // r5 <- PPN :PPN .x050 - we have ITLBTR entry
+	l.mtspr r2,r5,SPR_ITLBTR_BASE(0)   // set ITLBTR
+
+	EXCEPTION_LOAD_GPR6
+	EXCEPTION_LOAD_GPR5
+	EXCEPTION_LOAD_GPR4
+	EXCEPTION_LOAD_GPR3
+	EXCEPTION_LOAD_GPR2
+
+	l.rfe                              // SR <- ESR, PC <- EPC
+
+exit_with_no_itranslation:
+	EXCEPTION_LOAD_GPR4
+	EXCEPTION_LOAD_GPR6
+	l.j    _dispatch_bus_fault
+	l.nop
+
+/* ====================================================================== */
+/*
+ * Stuff below here shouldn't go into .head section... maybe this stuff
+ * can be moved to entry.S ???
+ */
+
+/* ==============================================[ DTLB miss handler ]=== */
+
+/*
+ * Comments:
+ *   Exception handlers are entered with MMU off so the following handler
+ *   needs to use physical addressing
+ *
+ */
+
+	.text
+ENTRY(dtlb_miss_handler)
+	EXCEPTION_STORE_GPR2
+	EXCEPTION_STORE_GPR3
+	EXCEPTION_STORE_GPR4
+	/*
+	 * get EA of the miss
+	 */
+	l.mfspr	r2,r0,SPR_EEAR_BASE
+	/*
+	 * pmd = (pmd_t *)(current_pgd + pgd_index(daddr));
+	 */
+	GET_CURRENT_PGD(r3,r4)		// r3 is current_pgd, r4 is temp
+	l.srli	r4,r2,0x18		// >> PAGE_SHIFT + (PAGE_SHIFT - 2)
+	l.slli	r4,r4,0x2		// to get address << 2
+	l.add	r3,r4,r3		// r4 is pgd_index(daddr)
+	/*
+	 * if (pmd_none(*pmd))
+	 *   goto pmd_none:
+	 */
+	tophys	(r4,r3)
+	l.lwz	r3,0x0(r4)		// get *pmd value
+	l.sfne	r3,r0
+	l.bnf	d_pmd_none
+	 l.addi	r3,r0,0xffffe000	// PAGE_MASK
+
+d_pmd_good:
+	/*
+	 * pte = *pte_offset(pmd, daddr);
+	 */
+	l.lwz	r4,0x0(r4)		// get **pmd value
+	l.and	r4,r4,r3		// & PAGE_MASK
+	l.srli	r2,r2,0xd		// >> PAGE_SHIFT, r2 == EEAR
+	l.andi	r3,r2,0x7ff		// (1UL << PAGE_SHIFT - 2) - 1
+	l.slli	r3,r3,0x2		// to get address << 2
+	l.add	r3,r3,r4
+	l.lwz	r3,0x0(r3)		// this is pte at last
+	/*
+	 * if (!pte_present(pte))
+	 */
+	l.andi	r4,r3,0x1
+	l.sfne	r4,r0			// is pte present
+	l.bnf	d_pte_not_present
+	l.addi	r4,r0,0xffffe3fa	// PAGE_MASK | DTLB_UP_CONVERT_MASK
+	/*
+	 * fill DTLB TR register
+	 */
+	l.and	r4,r3,r4		// apply the mask
+	// Determine number of DMMU sets
+	l.mfspr r2, r0, SPR_DMMUCFGR
+	l.andi	r2, r2, SPR_DMMUCFGR_NTS
+	l.srli	r2, r2, SPR_DMMUCFGR_NTS_OFF
+	l.ori	r3, r0, 0x1
+	l.sll	r3, r3, r2 	// r3 = number DMMU sets DMMUCFGR
+	l.addi	r2, r3, -1  	// r2 = nsets mask
+	l.mfspr	r3, r0, SPR_EEAR_BASE
+	l.srli	r3, r3, 0xd	// >> PAGE_SHIFT
+	l.and	r2, r3, r2	// calc offset:	 & (NUM_TLB_ENTRIES-1)
+	                                                   //NUM_TLB_ENTRIES
+	l.mtspr	r2,r4,SPR_DTLBTR_BASE(0)
+	/*
+	 * fill DTLB MR register
+	 */
+	l.slli	r3, r3, 0xd		/* << PAGE_SHIFT => EA & PAGE_MASK */
+	l.ori	r4,r3,0x1		// set hardware valid bit: DTBL_MR entry
+	l.mtspr	r2,r4,SPR_DTLBMR_BASE(0)
+
+	EXCEPTION_LOAD_GPR2
+	EXCEPTION_LOAD_GPR3
+	EXCEPTION_LOAD_GPR4
+	l.rfe
+d_pmd_none:
+d_pte_not_present:
+	EXCEPTION_LOAD_GPR2
+	EXCEPTION_LOAD_GPR3
+	EXCEPTION_LOAD_GPR4
+	EXCEPTION_HANDLE(_dtlb_miss_page_fault_handler)
+
+/* ==============================================[ ITLB miss handler ]=== */
+ENTRY(itlb_miss_handler)
+	EXCEPTION_STORE_GPR2
+	EXCEPTION_STORE_GPR3
+	EXCEPTION_STORE_GPR4
+	/*
+	 * get EA of the miss
+	 */
+	l.mfspr	r2,r0,SPR_EEAR_BASE
+
+	/*
+	 * pmd = (pmd_t *)(current_pgd + pgd_index(daddr));
+	 *
+	 */
+	GET_CURRENT_PGD(r3,r4)		// r3 is current_pgd, r5 is temp
+	l.srli	r4,r2,0x18		// >> PAGE_SHIFT + (PAGE_SHIFT - 2)
+	l.slli	r4,r4,0x2		// to get address << 2
+	l.add	r3,r4,r3		// r4 is pgd_index(daddr)
+	/*
+	 * if (pmd_none(*pmd))
+	 *   goto pmd_none:
+	 */
+	tophys	(r4,r3)
+	l.lwz	r3,0x0(r4)		// get *pmd value
+	l.sfne	r3,r0
+	l.bnf	i_pmd_none
+	 l.addi	r3,r0,0xffffe000	// PAGE_MASK
+
+i_pmd_good:
+	/*
+	 * pte = *pte_offset(pmd, iaddr);
+	 *
+	 */
+	l.lwz	r4,0x0(r4)		// get **pmd value
+	l.and	r4,r4,r3		// & PAGE_MASK
+	l.srli	r2,r2,0xd		// >> PAGE_SHIFT, r2 == EEAR
+	l.andi	r3,r2,0x7ff		// (1UL << PAGE_SHIFT - 2) - 1
+	l.slli	r3,r3,0x2		// to get address << 2
+	l.add	r3,r3,r4
+	l.lwz	r3,0x0(r3)		// this is pte at last
+	/*
+	 * if (!pte_present(pte))
+	 *
+	 */
+	l.andi	r4,r3,0x1
+	l.sfne	r4,r0			// is pte present
+	l.bnf	i_pte_not_present
+	 l.addi	r4,r0,0xffffe03a	// PAGE_MASK | ITLB_UP_CONVERT_MASK
+	/*
+	 * fill ITLB TR register
+	 */
+	l.and	r4,r3,r4		// apply the mask
+	l.andi	r3,r3,0x7c0		// _PAGE_EXEC | _PAGE_SRE | _PAGE_SWE |  _PAGE_URE | _PAGE_UWE
+	l.sfeq	r3,r0
+	l.bf	itlb_tr_fill //_workaround
+	// Determine number of IMMU sets
+	l.mfspr r2, r0, SPR_IMMUCFGR
+	l.andi	r2, r2, SPR_IMMUCFGR_NTS
+	l.srli	r2, r2, SPR_IMMUCFGR_NTS_OFF
+	l.ori	r3, r0, 0x1
+	l.sll	r3, r3, r2 	// r3 = number IMMU sets IMMUCFGR
+	l.addi	r2, r3, -1  	// r2 = nsets mask
+	l.mfspr	r3, r0, SPR_EEAR_BASE
+	l.srli	r3, r3, 0xd	// >> PAGE_SHIFT
+	l.and	r2, r3, r2	// calc offset:	 & (NUM_TLB_ENTRIES-1)
+
+/*
+ * __PHX__ :: fixme
+ * we should not just blindly set executable flags,
+ * but it does help with ping. the clean way would be to find out
+ * (and fix it) why stack doesn't have execution permissions
+ */
+
+itlb_tr_fill_workaround:
+	l.ori	r4,r4,0xc0		// | (SPR_ITLBTR_UXE | ITLBTR_SXE)
+itlb_tr_fill:
+	l.mtspr	r2,r4,SPR_ITLBTR_BASE(0)
+	/*
+	 * fill DTLB MR register
+	 */
+	l.slli	r3, r3, 0xd		/* << PAGE_SHIFT => EA & PAGE_MASK */
+	l.ori	r4,r3,0x1		// set hardware valid bit: ITBL_MR entry
+	l.mtspr	r2,r4,SPR_ITLBMR_BASE(0)
+
+	EXCEPTION_LOAD_GPR2
+	EXCEPTION_LOAD_GPR3
+	EXCEPTION_LOAD_GPR4
+	l.rfe
+
+i_pmd_none:
+i_pte_not_present:
+	EXCEPTION_LOAD_GPR2
+	EXCEPTION_LOAD_GPR3
+	EXCEPTION_LOAD_GPR4
+	EXCEPTION_HANDLE(_itlb_miss_page_fault_handler)
+
+/* ==============================================[ boot tlb handlers ]=== */
+
+
+/* =================================================[ debugging aids ]=== */
+
+	.align 64
+_immu_trampoline:
+	.space 64
+_immu_trampoline_top:
+
+#define TRAMP_SLOT_0		(0x0)
+#define TRAMP_SLOT_1		(0x4)
+#define TRAMP_SLOT_2		(0x8)
+#define TRAMP_SLOT_3		(0xc)
+#define TRAMP_SLOT_4		(0x10)
+#define TRAMP_SLOT_5		(0x14)
+#define TRAMP_FRAME_SIZE	(0x18)
+
+ENTRY(_immu_trampoline_workaround)
+	// r2 EEA
+	// r6 is physical EEA
+	tophys(r6,r2)
+
+	LOAD_SYMBOL_2_GPR(r5,_immu_trampoline)
+	tophys	(r3,r5)			// r3 is trampoline (physical)
+
+	LOAD_SYMBOL_2_GPR(r4,0x15000000)
+	l.sw	TRAMP_SLOT_0(r3),r4
+	l.sw	TRAMP_SLOT_1(r3),r4
+	l.sw	TRAMP_SLOT_4(r3),r4
+	l.sw	TRAMP_SLOT_5(r3),r4
+
+					// EPC = EEA - 0x4
+	l.lwz	r4,0x0(r6)		// load op @ EEA + 0x0 (fc address)
+	l.sw	TRAMP_SLOT_3(r3),r4	// store it to _immu_trampoline_data
+	l.lwz	r4,-0x4(r6)		// load op @ EEA - 0x4 (f8 address)
+	l.sw	TRAMP_SLOT_2(r3),r4	// store it to _immu_trampoline_data
+
+	l.srli  r5,r4,26                // check opcode for write access
+	l.sfeqi r5,0                    // l.j
+	l.bf    0f
+	l.sfeqi r5,0x11                 // l.jr
+	l.bf    1f
+	l.sfeqi r5,1                    // l.jal
+	l.bf    2f
+	l.sfeqi r5,0x12                 // l.jalr
+	l.bf    3f
+	l.sfeqi r5,3                    // l.bnf
+	l.bf    4f
+	l.sfeqi r5,4                    // l.bf
+	l.bf    5f
+99:
+	l.nop
+	l.j	99b			// should never happen
+	l.nop	1
+
+	// r2 is EEA
+	// r3 is trampoline address (physical)
+	// r4 is instruction
+	// r6 is physical(EEA)
+	//
+	// r5
+
+2:	// l.jal
+
+	/* 19 20 aa aa	l.movhi r9,0xaaaa
+	 * a9 29 bb bb  l.ori	r9,0xbbbb
+	 *
+	 * where 0xaaaabbbb is EEA + 0x4 shifted right 2
+	 */
+
+	l.addi	r6,r2,0x4		// this is 0xaaaabbbb
+
+					// l.movhi r9,0xaaaa
+	l.ori	r5,r0,0x1920		// 0x1920 == l.movhi r9
+	l.sh	(TRAMP_SLOT_0+0x0)(r3),r5
+	l.srli	r5,r6,16
+	l.sh	(TRAMP_SLOT_0+0x2)(r3),r5
+
+					// l.ori   r9,0xbbbb
+	l.ori	r5,r0,0xa929		// 0xa929 == l.ori r9
+	l.sh	(TRAMP_SLOT_1+0x0)(r3),r5
+	l.andi	r5,r6,0xffff
+	l.sh	(TRAMP_SLOT_1+0x2)(r3),r5
+
+	/* falthrough, need to set up new jump offset */
+
+
+0:	// l.j
+	l.slli	r6,r4,6			// original offset shifted left 6 - 2
+//	l.srli	r6,r6,6			// original offset shifted right 2
+
+	l.slli	r4,r2,4			// old jump position: EEA shifted left 4
+//	l.srli	r4,r4,6			// old jump position: shifted right 2
+
+	l.addi	r5,r3,0xc		// new jump position (physical)
+	l.slli	r5,r5,4			// new jump position: shifted left 4
+
+	// calculate new jump offset
+	// new_off = old_off + (old_jump - new_jump)
+
+	l.sub	r5,r4,r5		// old_jump - new_jump
+	l.add	r5,r6,r5		// orig_off + (old_jump - new_jump)
+	l.srli	r5,r5,6			// new offset shifted right 2
+
+	// r5 is new jump offset
+					// l.j has opcode 0x0...
+	l.sw	TRAMP_SLOT_2(r3),r5	// write it back
+
+	l.j	trampoline_out
+	l.nop
+
+/* ----------------------------- */
+
+3:	// l.jalr
+
+	/* 19 20 aa aa	l.movhi r9,0xaaaa
+	 * a9 29 bb bb  l.ori	r9,0xbbbb
+	 *
+	 * where 0xaaaabbbb is EEA + 0x4 shifted right 2
+	 */
+
+	l.addi	r6,r2,0x4		// this is 0xaaaabbbb
+
+					// l.movhi r9,0xaaaa
+	l.ori	r5,r0,0x1920		// 0x1920 == l.movhi r9
+	l.sh	(TRAMP_SLOT_0+0x0)(r3),r5
+	l.srli	r5,r6,16
+	l.sh	(TRAMP_SLOT_0+0x2)(r3),r5
+
+					// l.ori   r9,0xbbbb
+	l.ori	r5,r0,0xa929		// 0xa929 == l.ori r9
+	l.sh	(TRAMP_SLOT_1+0x0)(r3),r5
+	l.andi	r5,r6,0xffff
+	l.sh	(TRAMP_SLOT_1+0x2)(r3),r5
+
+	l.lhz	r5,(TRAMP_SLOT_2+0x0)(r3)	// load hi part of jump instruction
+	l.andi	r5,r5,0x3ff		// clear out opcode part
+	l.ori	r5,r5,0x4400		// opcode changed from l.jalr -> l.jr
+	l.sh	(TRAMP_SLOT_2+0x0)(r3),r5 // write it back
+
+	/* falthrough */
+
+1:	// l.jr
+	l.j	trampoline_out
+	l.nop
+
+/* ----------------------------- */
+
+4:	// l.bnf
+5:	// l.bf
+	l.slli	r6,r4,6			// original offset shifted left 6 - 2
+//	l.srli	r6,r6,6			// original offset shifted right 2
+
+	l.slli	r4,r2,4			// old jump position: EEA shifted left 4
+//	l.srli	r4,r4,6			// old jump position: shifted right 2
+
+	l.addi	r5,r3,0xc		// new jump position (physical)
+	l.slli	r5,r5,4			// new jump position: shifted left 4
+
+	// calculate new jump offset
+	// new_off = old_off + (old_jump - new_jump)
+
+	l.add	r6,r6,r4		// (orig_off + old_jump)
+	l.sub	r6,r6,r5		// (orig_off + old_jump) - new_jump
+	l.srli	r6,r6,6			// new offset shifted right 2
+
+	// r6 is new jump offset
+	l.lwz	r4,(TRAMP_SLOT_2+0x0)(r3)	// load jump instruction
+	l.srli	r4,r4,16
+	l.andi	r4,r4,0xfc00		// get opcode part
+	l.slli	r4,r4,16
+	l.or	r6,r4,r6		// l.b(n)f new offset
+	l.sw	TRAMP_SLOT_2(r3),r6	// write it back
+
+	/* we need to add l.j to EEA + 0x8 */
+	tophys	(r4,r2)			// may not be needed (due to shifts down_
+	l.addi	r4,r4,(0x8 - 0x8)	// jump target = r2 + 0x8 (compensate for 0x8)
+					// jump position = r5 + 0x8 (0x8 compensated)
+	l.sub	r4,r4,r5		// jump offset = target - new_position + 0x8
+
+	l.slli	r4,r4,4			// the amount of info in imediate of jump
+	l.srli	r4,r4,6			// jump instruction with offset
+	l.sw	TRAMP_SLOT_4(r3),r4	// write it to 4th slot
+
+	/* fallthrough */
+
+trampoline_out:
+	// set up new EPC to point to our trampoline code
+	LOAD_SYMBOL_2_GPR(r5,_immu_trampoline)
+	l.mtspr	r0,r5,SPR_EPCR_BASE
+
+	// immu_trampoline is (4x) CACHE_LINE aligned
+	// and only 6 instructions long,
+	// so we need to invalidate only 2 lines
+
+	/* Establish cache block size
+	   If BS=0, 16;
+	   If BS=1, 32;
+	   r14 contain block size
+	*/
+	l.mfspr r21,r0,SPR_ICCFGR
+	l.andi	r21,r21,SPR_ICCFGR_CBS
+	l.srli	r21,r21,7
+	l.ori	r23,r0,16
+	l.sll	r14,r23,r21
+
+	l.mtspr	r0,r5,SPR_ICBIR
+	l.add	r5,r5,r14
+	l.mtspr	r0,r5,SPR_ICBIR
+
+	l.jr	r9
+	l.nop
+
+
+/*
+ * DSCR: prints a string referenced by r3.
+ *
+ * PRMS: r3     	- address of the first character of null
+ *			terminated string to be printed
+ *
+ * PREQ: UART at UART_BASE_ADD has to be initialized
+ *
+ * POST: caller should be aware that r3, r9 are changed
+ */
+ENTRY(_emergency_print)
+	EMERGENCY_PRINT_STORE_GPR4
+	EMERGENCY_PRINT_STORE_GPR5
+	EMERGENCY_PRINT_STORE_GPR6
+	EMERGENCY_PRINT_STORE_GPR7
+2:
+	l.lbz	r7,0(r3)
+	l.sfeq	r7,r0
+	l.bf	9f
+	l.nop
+
+// putc:
+	l.movhi r4,hi(UART_BASE_ADD)
+
+	l.addi  r6,r0,0x20
+1:      l.lbz   r5,5(r4)
+	l.andi  r5,r5,0x20
+	l.sfeq  r5,r6
+	l.bnf   1b
+	l.nop
+
+	l.sb    0(r4),r7
+
+	l.addi  r6,r0,0x60
+1:      l.lbz   r5,5(r4)
+	l.andi  r5,r5,0x60
+	l.sfeq  r5,r6
+	l.bnf   1b
+	l.nop
+
+	/* next character */
+	l.j	2b
+	l.addi	r3,r3,0x1
+
+9:
+	EMERGENCY_PRINT_LOAD_GPR7
+	EMERGENCY_PRINT_LOAD_GPR6
+	EMERGENCY_PRINT_LOAD_GPR5
+	EMERGENCY_PRINT_LOAD_GPR4
+	l.jr	r9
+	l.nop
+
+ENTRY(_emergency_print_nr)
+	EMERGENCY_PRINT_STORE_GPR4
+	EMERGENCY_PRINT_STORE_GPR5
+	EMERGENCY_PRINT_STORE_GPR6
+	EMERGENCY_PRINT_STORE_GPR7
+	EMERGENCY_PRINT_STORE_GPR8
+
+	l.addi	r8,r0,32		// shift register
+
+1:	/* remove leading zeros */
+	l.addi	r8,r8,-0x4
+	l.srl	r7,r3,r8
+	l.andi	r7,r7,0xf
+
+	/* don't skip the last zero if number == 0x0 */
+	l.sfeqi	r8,0x4
+	l.bf	2f
+	l.nop
+
+	l.sfeq	r7,r0
+	l.bf	1b
+	l.nop
+
+2:
+	l.srl	r7,r3,r8
+
+	l.andi	r7,r7,0xf
+	l.sflts	r8,r0
+	l.bf	9f
+
+	l.sfgtui r7,0x9
+	l.bnf	8f
+	l.nop
+	l.addi	r7,r7,0x27
+
+8:
+	l.addi	r7,r7,0x30
+// putc:
+	l.movhi r4,hi(UART_BASE_ADD)
+
+	l.addi  r6,r0,0x20
+1:      l.lbz   r5,5(r4)
+	l.andi  r5,r5,0x20
+	l.sfeq  r5,r6
+	l.bnf   1b
+	l.nop
+
+	l.sb    0(r4),r7
+
+	l.addi  r6,r0,0x60
+1:      l.lbz   r5,5(r4)
+	l.andi  r5,r5,0x60
+	l.sfeq  r5,r6
+	l.bnf   1b
+	l.nop
+
+	/* next character */
+	l.j	2b
+	l.addi	r8,r8,-0x4
+
+9:
+	EMERGENCY_PRINT_LOAD_GPR8
+	EMERGENCY_PRINT_LOAD_GPR7
+	EMERGENCY_PRINT_LOAD_GPR6
+	EMERGENCY_PRINT_LOAD_GPR5
+	EMERGENCY_PRINT_LOAD_GPR4
+	l.jr	r9
+	l.nop
+
+
+/*
+ * This should be used for debugging only.
+ * It messes up the Linux early serial output
+ * somehow, so use it sparingly and essentially
+ * only if you need to debug something that goes wrong
+ * before Linux gets the early serial going.
+ *
+ * Furthermore, you'll have to make sure you set the
+ * UART_DEVISOR correctly according to the system
+ * clock rate.
+ *
+ *
+ */
+
+
+
+#define SYS_CLK            20000000
+//#define SYS_CLK            1843200
+#define OR32_CONSOLE_BAUD  115200
+#define UART_DIVISOR       SYS_CLK/(16*OR32_CONSOLE_BAUD)
+
+ENTRY(_early_uart_init)
+	l.movhi	r3,hi(UART_BASE_ADD)
+
+	l.addi	r4,r0,0x7
+	l.sb	0x2(r3),r4
+
+	l.addi	r4,r0,0x0
+	l.sb	0x1(r3),r4
+
+	l.addi	r4,r0,0x3
+	l.sb	0x3(r3),r4
+
+	l.lbz	r5,3(r3)
+	l.ori	r4,r5,0x80
+	l.sb	0x3(r3),r4
+	l.addi	r4,r0,((UART_DIVISOR>>8) & 0x000000ff)
+	l.sb	UART_DLM(r3),r4
+	l.addi  r4,r0,((UART_DIVISOR) & 0x000000ff)
+	l.sb	UART_DLL(r3),r4
+	l.sb	0x3(r3),r5
+
+	l.jr	r9
+	l.nop
+
+	.align	0x1000
+	.global _secondary_evbar
+_secondary_evbar:
+
+	.space 0x800
+	/* Just disable interrupts and Return */
+	l.ori	r3,r0,SPR_SR_SM
+	l.mtspr	r0,r3,SPR_ESR_BASE
+	l.rfe
+
+
+	.section .rodata
+_string_unhandled_exception:
+	.string "\n\rRunarunaround: Unhandled exception 0x\0"
+
+_string_epc_prefix:
+	.string ": EPC=0x\0"
+
+_string_nl:
+	.string "\n\r\0"
+
+
+/* ========================================[ page aligned structures ]=== */
+
+/*
+ * .data section should be page aligned
+ *	(look into arch/or32/kernel/vmlinux.lds)
+ */
+	.section .data,"aw"
+	.align	8192
+	.global  empty_zero_page
+empty_zero_page:
+	.space  8192
+
+	.global  swapper_pg_dir
+swapper_pg_dir:
+	.space  8192
+
+	.global	_unhandled_stack
+_unhandled_stack:
+	.space	8192
+_unhandled_stack_top:
+
+/* ============================================================[ EOF ]=== */
diff --git a/arch/openrisc/kernel/irq.c b/arch/openrisc/kernel/irq.c
new file mode 100644
index 0000000..5f9445e
--- /dev/null
+++ b/arch/openrisc/kernel/irq.c
@@ -0,0 +1,47 @@
+/*
+ * OpenRISC irq.c
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/ftrace.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/export.h>
+#include <linux/irqflags.h>
+
+/* read interrupt enabled status */
+unsigned long arch_local_save_flags(void)
+{
+	return mfspr(SPR_SR) & (SPR_SR_IEE|SPR_SR_TEE);
+}
+EXPORT_SYMBOL(arch_local_save_flags);
+
+/* set interrupt enabled status */
+void arch_local_irq_restore(unsigned long flags)
+{
+	mtspr(SPR_SR, ((mfspr(SPR_SR) & ~(SPR_SR_IEE|SPR_SR_TEE)) | flags));
+}
+EXPORT_SYMBOL(arch_local_irq_restore);
+
+void __init init_IRQ(void)
+{
+	irqchip_init();
+}
+
+void __irq_entry do_IRQ(struct pt_regs *regs)
+{
+	handle_arch_irq(regs);
+}
diff --git a/arch/openrisc/kernel/module.c b/arch/openrisc/kernel/module.c
new file mode 100644
index 0000000..ef872ae
--- /dev/null
+++ b/arch/openrisc/kernel/module.c
@@ -0,0 +1,70 @@
+/*
+ * OpenRISC module.c
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/moduleloader.h>
+#include <linux/elf.h>
+
+int apply_relocate_add(Elf32_Shdr *sechdrs,
+		       const char *strtab,
+		       unsigned int symindex,
+		       unsigned int relsec,
+		       struct module *me)
+{
+	unsigned int i;
+	Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
+	Elf32_Sym *sym;
+	uint32_t *location;
+	uint32_t value;
+
+	pr_debug("Applying relocate section %u to %u\n", relsec,
+		 sechdrs[relsec].sh_info);
+	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
+		/* This is where to make the change */
+		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+			+ rel[i].r_offset;
+
+		/* This is the symbol it is referring to.  Note that all
+		   undefined symbols have been resolved.  */
+		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
+			+ ELF32_R_SYM(rel[i].r_info);
+		value = sym->st_value + rel[i].r_addend;
+
+		switch (ELF32_R_TYPE(rel[i].r_info)) {
+		case R_OR32_32:
+			*location = value;
+			break;
+		case R_OR32_CONST:
+			*((uint16_t *)location + 1) = value;
+			break;
+		case R_OR32_CONSTH:
+			*((uint16_t *)location + 1) = value >> 16;
+			break;
+		case R_OR32_JUMPTARG:
+			value -= (uint32_t)location;
+			value >>= 2;
+			value &= 0x03ffffff;
+			value |= *location & 0xfc000000;
+			*location = value;
+			break;
+		default:
+			pr_err("module %s: Unknown relocation: %u\n",
+			       me->name, ELF32_R_TYPE(rel[i].r_info));
+			break;
+		}
+	}
+
+	return 0;
+}
diff --git a/arch/openrisc/kernel/or32_ksyms.c b/arch/openrisc/kernel/or32_ksyms.c
new file mode 100644
index 0000000..d7260fd
--- /dev/null
+++ b/arch/openrisc/kernel/or32_ksyms.c
@@ -0,0 +1,51 @@
+/*
+ * OpenRISC or32_ksyms.c
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/export.h>
+#include <linux/elfcore.h>
+#include <linux/sched.h>
+#include <linux/in6.h>
+#include <linux/interrupt.h>
+#include <linux/vmalloc.h>
+#include <linux/semaphore.h>
+
+#include <asm/processor.h>
+#include <linux/uaccess.h>
+#include <asm/checksum.h>
+#include <asm/io.h>
+#include <asm/hardirq.h>
+#include <asm/delay.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+
+#define DECLARE_EXPORT(name) extern void name(void); EXPORT_SYMBOL(name)
+
+/* compiler generated symbols */
+DECLARE_EXPORT(__udivsi3);
+DECLARE_EXPORT(__divsi3);
+DECLARE_EXPORT(__umodsi3);
+DECLARE_EXPORT(__modsi3);
+DECLARE_EXPORT(__muldi3);
+DECLARE_EXPORT(__ashrdi3);
+DECLARE_EXPORT(__ashldi3);
+DECLARE_EXPORT(__lshrdi3);
+DECLARE_EXPORT(__ucmpdi2);
+
+EXPORT_SYMBOL(empty_zero_page);
+EXPORT_SYMBOL(__copy_tofrom_user);
+EXPORT_SYMBOL(__clear_user);
+EXPORT_SYMBOL(memset);
diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c
new file mode 100644
index 0000000..8739b6d
--- /dev/null
+++ b/arch/openrisc/kernel/process.c
@@ -0,0 +1,284 @@
+/*
+ * OpenRISC process.c
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ *
+ * This file handles the architecture-dependent parts of process handling...
+ */
+
+#define __KERNEL_SYSCALLS__
+#include <stdarg.h>
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/task.h>
+#include <linux/sched/task_stack.h>
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
+#include <linux/ptrace.h>
+#include <linux/slab.h>
+#include <linux/elfcore.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/init_task.h>
+#include <linux/mqueue.h>
+#include <linux/fs.h>
+
+#include <linux/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+#include <asm/spr_defs.h>
+
+#include <linux/smp.h>
+
+/*
+ * Pointer to Current thread info structure.
+ *
+ * Used at user space -> kernel transitions.
+ */
+struct thread_info *current_thread_info_set[NR_CPUS] = { &init_thread_info, };
+
+void machine_restart(void)
+{
+	printk(KERN_INFO "*** MACHINE RESTART ***\n");
+	__asm__("l.nop 1");
+}
+
+/*
+ * Similar to machine_power_off, but don't shut off power.  Add code
+ * here to freeze the system for e.g. post-mortem debug purpose when
+ * possible.  This halt has nothing to do with the idle halt.
+ */
+void machine_halt(void)
+{
+	printk(KERN_INFO "*** MACHINE HALT ***\n");
+	__asm__("l.nop 1");
+}
+
+/* If or when software power-off is implemented, add code here.  */
+void machine_power_off(void)
+{
+	printk(KERN_INFO "*** MACHINE POWER OFF ***\n");
+	__asm__("l.nop 1");
+}
+
+/*
+ * Send the doze signal to the cpu if available.
+ * Make sure, that all interrupts are enabled
+ */
+void arch_cpu_idle(void)
+{
+	local_irq_enable();
+	if (mfspr(SPR_UPR) & SPR_UPR_PMP)
+		mtspr(SPR_PMR, mfspr(SPR_PMR) | SPR_PMR_DME);
+}
+
+void (*pm_power_off) (void) = machine_power_off;
+EXPORT_SYMBOL(pm_power_off);
+
+/*
+ * When a process does an "exec", machine state like FPU and debug
+ * registers need to be reset.  This is a hook function for that.
+ * Currently we don't have any such state to reset, so this is empty.
+ */
+void flush_thread(void)
+{
+}
+
+void show_regs(struct pt_regs *regs)
+{
+	extern void show_registers(struct pt_regs *regs);
+
+	show_regs_print_info(KERN_DEFAULT);
+	/* __PHX__ cleanup this mess */
+	show_registers(regs);
+}
+
+void release_thread(struct task_struct *dead_task)
+{
+}
+
+/*
+ * Copy the thread-specific (arch specific) info from the current
+ * process to the new one p
+ */
+extern asmlinkage void ret_from_fork(void);
+
+/*
+ * copy_thread
+ * @clone_flags: flags
+ * @usp: user stack pointer or fn for kernel thread
+ * @arg: arg to fn for kernel thread; always NULL for userspace thread
+ * @p: the newly created task
+ * @regs: CPU context to copy for userspace thread; always NULL for kthread
+ *
+ * At the top of a newly initialized kernel stack are two stacked pt_reg
+ * structures.  The first (topmost) is the userspace context of the thread.
+ * The second is the kernelspace context of the thread.
+ *
+ * A kernel thread will not be returning to userspace, so the topmost pt_regs
+ * struct can be uninitialized; it _does_ need to exist, though, because
+ * a kernel thread can become a userspace thread by doing a kernel_execve, in
+ * which case the topmost context will be initialized and used for 'returning'
+ * to userspace.
+ *
+ * The second pt_reg struct needs to be initialized to 'return' to
+ * ret_from_fork.  A kernel thread will need to set r20 to the address of
+ * a function to call into (with arg in r22); userspace threads need to set
+ * r20 to NULL in which case ret_from_fork will just continue a return to
+ * userspace.
+ *
+ * A kernel thread 'fn' may return; this is effectively what happens when
+ * kernel_execve is called.  In that case, the userspace pt_regs must have
+ * been initialized (which kernel_execve takes care of, see start_thread
+ * below); ret_from_fork will then continue its execution causing the
+ * 'kernel thread' to return to userspace as a userspace thread.
+ */
+
+int
+copy_thread(unsigned long clone_flags, unsigned long usp,
+	    unsigned long arg, struct task_struct *p)
+{
+	struct pt_regs *userregs;
+	struct pt_regs *kregs;
+	unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
+	unsigned long top_of_kernel_stack;
+
+	top_of_kernel_stack = sp;
+
+	/* Locate userspace context on stack... */
+	sp -= STACK_FRAME_OVERHEAD;	/* redzone */
+	sp -= sizeof(struct pt_regs);
+	userregs = (struct pt_regs *) sp;
+
+	/* ...and kernel context */
+	sp -= STACK_FRAME_OVERHEAD;	/* redzone */
+	sp -= sizeof(struct pt_regs);
+	kregs = (struct pt_regs *)sp;
+
+	if (unlikely(p->flags & PF_KTHREAD)) {
+		memset(kregs, 0, sizeof(struct pt_regs));
+		kregs->gpr[20] = usp; /* fn, kernel thread */
+		kregs->gpr[22] = arg;
+	} else {
+		*userregs = *current_pt_regs();
+
+		if (usp)
+			userregs->sp = usp;
+
+		/*
+		 * For CLONE_SETTLS set "tp" (r10) to the TLS pointer passed to sys_clone.
+		 *
+		 * The kernel entry is:
+		 *	int clone (long flags, void *child_stack, int *parent_tid,
+		 *		int *child_tid, struct void *tls)
+		 *
+		 * This makes the source r7 in the kernel registers.
+		 */
+		if (clone_flags & CLONE_SETTLS)
+			userregs->gpr[10] = userregs->gpr[7];
+
+		userregs->gpr[11] = 0;	/* Result from fork() */
+
+		kregs->gpr[20] = 0;	/* Userspace thread */
+	}
+
+	/*
+	 * _switch wants the kernel stack page in pt_regs->sp so that it
+	 * can restore it to thread_info->ksp... see _switch for details.
+	 */
+	kregs->sp = top_of_kernel_stack;
+	kregs->gpr[9] = (unsigned long)ret_from_fork;
+
+	task_thread_info(p)->ksp = (unsigned long)kregs;
+
+	return 0;
+}
+
+/*
+ * Set up a thread for executing a new program
+ */
+void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
+{
+	unsigned long sr = mfspr(SPR_SR) & ~SPR_SR_SM;
+
+	memset(regs, 0, sizeof(struct pt_regs));
+
+	regs->pc = pc;
+	regs->sr = sr;
+	regs->sp = sp;
+}
+
+/* Fill in the fpu structure for a core dump.  */
+int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpu)
+{
+	/* TODO */
+	return 0;
+}
+
+extern struct thread_info *_switch(struct thread_info *old_ti,
+				   struct thread_info *new_ti);
+extern int lwa_flag;
+
+struct task_struct *__switch_to(struct task_struct *old,
+				struct task_struct *new)
+{
+	struct task_struct *last;
+	struct thread_info *new_ti, *old_ti;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	/* current_set is an array of saved current pointers
+	 * (one for each cpu). we need them at user->kernel transition,
+	 * while we save them at kernel->user transition
+	 */
+	new_ti = new->stack;
+	old_ti = old->stack;
+
+	lwa_flag = 0;
+
+	current_thread_info_set[smp_processor_id()] = new_ti;
+	last = (_switch(old_ti, new_ti))->task;
+
+	local_irq_restore(flags);
+
+	return last;
+}
+
+/*
+ * Write out registers in core dump format, as defined by the
+ * struct user_regs_struct
+ */
+void dump_elf_thread(elf_greg_t *dest, struct pt_regs* regs)
+{
+	dest[0] = 0; /* r0 */
+	memcpy(dest+1, regs->gpr+1, 31*sizeof(unsigned long));
+	dest[32] = regs->pc;
+	dest[33] = regs->sr;
+	dest[34] = 0;
+	dest[35] = 0;
+}
+
+unsigned long get_wchan(struct task_struct *p)
+{
+	/* TODO */
+
+	return 0;
+}
diff --git a/arch/openrisc/kernel/prom.c b/arch/openrisc/kernel/prom.c
new file mode 100644
index 0000000..6a44340
--- /dev/null
+++ b/arch/openrisc/kernel/prom.c
@@ -0,0 +1,32 @@
+/*
+ * OpenRISC prom.c
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ *
+ * Architecture specific procedures for creating, accessing and
+ * interpreting the device tree.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/memblock.h>
+#include <linux/of_fdt.h>
+
+#include <asm/page.h>
+
+void __init early_init_devtree(void *params)
+{
+	early_init_dt_scan(params);
+	memblock_allow_resize();
+}
diff --git a/arch/openrisc/kernel/ptrace.c b/arch/openrisc/kernel/ptrace.c
new file mode 100644
index 0000000..eb97a8e
--- /dev/null
+++ b/arch/openrisc/kernel/ptrace.c
@@ -0,0 +1,205 @@
+/*
+ * OpenRISC ptrace.c
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2005 Gyorgy Jeney <nog@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+#include <linux/string.h>
+
+#include <linux/mm.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/audit.h>
+#include <linux/regset.h>
+#include <linux/tracehook.h>
+#include <linux/elf.h>
+
+#include <asm/thread_info.h>
+#include <asm/segment.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+
+/*
+ * Copy the thread state to a regset that can be interpreted by userspace.
+ *
+ * It doesn't matter what our internal pt_regs structure looks like.  The
+ * important thing is that we export a consistent view of the thread state
+ * to userspace.  As such, we need to make sure that the regset remains
+ * ABI compatible as defined by the struct user_regs_struct:
+ *
+ * (Each item is a 32-bit word)
+ * r0 = 0 (exported for clarity)
+ * 31 GPRS r1-r31
+ * PC (Program counter)
+ * SR (Supervision register)
+ */
+static int genregs_get(struct task_struct *target,
+		       const struct user_regset *regset,
+		       unsigned int pos, unsigned int count,
+		       void *kbuf, void __user * ubuf)
+{
+	const struct pt_regs *regs = task_pt_regs(target);
+	int ret;
+
+	/* r0 */
+	ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 0, 4);
+
+	if (!ret)
+		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+					  regs->gpr+1, 4, 4*32);
+	if (!ret)
+		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+				  &regs->pc, 4*32, 4*33);
+	if (!ret)
+		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+					  &regs->sr, 4*33, 4*34);
+	if (!ret)
+		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
+					       4*34, -1);
+
+	return ret;
+}
+
+/*
+ * Set the thread state from a regset passed in via ptrace
+ */
+static int genregs_set(struct task_struct *target,
+		       const struct user_regset *regset,
+		       unsigned int pos, unsigned int count,
+		       const void *kbuf, const void __user * ubuf)
+{
+	struct pt_regs *regs = task_pt_regs(target);
+	int ret;
+
+	/* ignore r0 */
+	ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, 4);
+	/* r1 - r31 */
+	if (!ret)
+		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+					 regs->gpr+1, 4, 4*32);
+	/* PC */
+	if (!ret)
+		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 &regs->pc, 4*32, 4*33);
+	/*
+	 * Skip SR and padding... userspace isn't allowed to changes bits in
+	 * the Supervision register
+	 */
+	if (!ret)
+		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
+						4*33, -1);
+
+	return ret;
+}
+
+/*
+ * Define the register sets available on OpenRISC under Linux
+ */
+enum or1k_regset {
+	REGSET_GENERAL,
+};
+
+static const struct user_regset or1k_regsets[] = {
+	[REGSET_GENERAL] = {
+			    .core_note_type = NT_PRSTATUS,
+			    .n = ELF_NGREG,
+			    .size = sizeof(long),
+			    .align = sizeof(long),
+			    .get = genregs_get,
+			    .set = genregs_set,
+			    },
+};
+
+static const struct user_regset_view user_or1k_native_view = {
+	.name = "or1k",
+	.e_machine = EM_OPENRISC,
+	.regsets = or1k_regsets,
+	.n = ARRAY_SIZE(or1k_regsets),
+};
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+	return &user_or1k_native_view;
+}
+
+/*
+ * does not yet catch signals sent when the child dies.
+ * in exit.c or in signal.c.
+ */
+
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ *
+ * Make sure the single step bit is not set.
+ */
+void ptrace_disable(struct task_struct *child)
+{
+	pr_debug("ptrace_disable(): TODO\n");
+
+	user_disable_single_step(child);
+	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+}
+
+long arch_ptrace(struct task_struct *child, long request, unsigned long addr,
+		 unsigned long data)
+{
+	int ret;
+
+	switch (request) {
+	default:
+		ret = ptrace_request(child, request, addr, data);
+		break;
+	}
+
+	return ret;
+}
+
+/*
+ * Notification of system call entry/exit
+ * - triggered by current->work.syscall_trace
+ */
+asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
+{
+	long ret = 0;
+
+	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
+	    tracehook_report_syscall_entry(regs))
+		/*
+		 * Tracing decided this syscall should not happen.
+		 * We'll return a bogus call number to get an ENOSYS
+		 * error, but leave the original number in <something>.
+		 */
+		ret = -1L;
+
+	audit_syscall_entry(regs->gpr[11], regs->gpr[3], regs->gpr[4],
+			    regs->gpr[5], regs->gpr[6]);
+
+	return ret ? : regs->gpr[11];
+}
+
+asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
+{
+	int step;
+
+	audit_syscall_exit(regs);
+
+	step = test_thread_flag(TIF_SINGLESTEP);
+	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
+		tracehook_report_syscall_exit(regs, step);
+}
diff --git a/arch/openrisc/kernel/setup.c b/arch/openrisc/kernel/setup.c
new file mode 100644
index 0000000..9d28ab1
--- /dev/null
+++ b/arch/openrisc/kernel/setup.c
@@ -0,0 +1,413 @@
+/*
+ * OpenRISC setup.c
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ *
+ * This file handles the architecture-dependent parts of initialization
+ */
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
+#include <linux/ptrace.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/ioport.h>
+#include <linux/delay.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/seq_file.h>
+#include <linux/serial.h>
+#include <linux/initrd.h>
+#include <linux/of_fdt.h>
+#include <linux/of.h>
+#include <linux/memblock.h>
+#include <linux/device.h>
+
+#include <asm/sections.h>
+#include <asm/segment.h>
+#include <asm/pgtable.h>
+#include <asm/types.h>
+#include <asm/setup.h>
+#include <asm/io.h>
+#include <asm/cpuinfo.h>
+#include <asm/delay.h>
+
+#include "vmlinux.h"
+
+static void __init setup_memory(void)
+{
+	unsigned long ram_start_pfn;
+	unsigned long ram_end_pfn;
+	phys_addr_t memory_start, memory_end;
+	struct memblock_region *region;
+
+	memory_end = memory_start = 0;
+
+	/* Find main memory where is the kernel, we assume its the only one */
+	for_each_memblock(memory, region) {
+		memory_start = region->base;
+		memory_end = region->base + region->size;
+		printk(KERN_INFO "%s: Memory: 0x%x-0x%x\n", __func__,
+		       memory_start, memory_end);
+	}
+
+	if (!memory_end) {
+		panic("No memory!");
+	}
+
+	ram_start_pfn = PFN_UP(memory_start);
+	ram_end_pfn = PFN_DOWN(memblock_end_of_DRAM());
+
+	/* setup bootmem globals (we use no_bootmem, but mm still depends on this) */
+	min_low_pfn = ram_start_pfn;
+	max_low_pfn = ram_end_pfn;
+	max_pfn = ram_end_pfn;
+
+	/*
+	 * initialize the boot-time allocator (with low memory only).
+	 *
+	 * This makes the memory from the end of the kernel to the end of
+	 * RAM usable.
+	 */
+	memblock_reserve(__pa(_stext), _end - _stext);
+
+	early_init_fdt_reserve_self();
+	early_init_fdt_scan_reserved_mem();
+
+	memblock_dump_all();
+}
+
+struct cpuinfo_or1k cpuinfo_or1k[NR_CPUS];
+
+static void print_cpuinfo(void)
+{
+	unsigned long upr = mfspr(SPR_UPR);
+	unsigned long vr = mfspr(SPR_VR);
+	unsigned int version;
+	unsigned int revision;
+	struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[smp_processor_id()];
+
+	version = (vr & SPR_VR_VER) >> 24;
+	revision = (vr & SPR_VR_REV);
+
+	printk(KERN_INFO "CPU: OpenRISC-%x (revision %d) @%d MHz\n",
+	       version, revision, cpuinfo->clock_frequency / 1000000);
+
+	if (!(upr & SPR_UPR_UP)) {
+		printk(KERN_INFO
+		       "-- no UPR register... unable to detect configuration\n");
+		return;
+	}
+
+	if (upr & SPR_UPR_DCP)
+		printk(KERN_INFO
+		       "-- dcache: %4d bytes total, %2d bytes/line, %d way(s)\n",
+		       cpuinfo->dcache_size, cpuinfo->dcache_block_size,
+		       cpuinfo->dcache_ways);
+	else
+		printk(KERN_INFO "-- dcache disabled\n");
+	if (upr & SPR_UPR_ICP)
+		printk(KERN_INFO
+		       "-- icache: %4d bytes total, %2d bytes/line, %d way(s)\n",
+		       cpuinfo->icache_size, cpuinfo->icache_block_size,
+		       cpuinfo->icache_ways);
+	else
+		printk(KERN_INFO "-- icache disabled\n");
+
+	if (upr & SPR_UPR_DMP)
+		printk(KERN_INFO "-- dmmu: %4d entries, %lu way(s)\n",
+		       1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),
+		       1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW));
+	if (upr & SPR_UPR_IMP)
+		printk(KERN_INFO "-- immu: %4d entries, %lu way(s)\n",
+		       1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),
+		       1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW));
+
+	printk(KERN_INFO "-- additional features:\n");
+	if (upr & SPR_UPR_DUP)
+		printk(KERN_INFO "-- debug unit\n");
+	if (upr & SPR_UPR_PCUP)
+		printk(KERN_INFO "-- performance counters\n");
+	if (upr & SPR_UPR_PMP)
+		printk(KERN_INFO "-- power management\n");
+	if (upr & SPR_UPR_PICP)
+		printk(KERN_INFO "-- PIC\n");
+	if (upr & SPR_UPR_TTP)
+		printk(KERN_INFO "-- timer\n");
+	if (upr & SPR_UPR_CUP)
+		printk(KERN_INFO "-- custom unit(s)\n");
+}
+
+static struct device_node *setup_find_cpu_node(int cpu)
+{
+	u32 hwid;
+	struct device_node *cpun;
+	struct device_node *cpus = of_find_node_by_path("/cpus");
+
+	for_each_available_child_of_node(cpus, cpun) {
+		if (of_property_read_u32(cpun, "reg", &hwid))
+			continue;
+		if (hwid == cpu)
+			return cpun;
+	}
+
+	return NULL;
+}
+
+void __init setup_cpuinfo(void)
+{
+	struct device_node *cpu;
+	unsigned long iccfgr, dccfgr;
+	unsigned long cache_set_size;
+	int cpu_id = smp_processor_id();
+	struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[cpu_id];
+
+	cpu = setup_find_cpu_node(cpu_id);
+	if (!cpu)
+		panic("Couldn't find CPU%d in device tree...\n", cpu_id);
+
+	iccfgr = mfspr(SPR_ICCFGR);
+	cpuinfo->icache_ways = 1 << (iccfgr & SPR_ICCFGR_NCW);
+	cache_set_size = 1 << ((iccfgr & SPR_ICCFGR_NCS) >> 3);
+	cpuinfo->icache_block_size = 16 << ((iccfgr & SPR_ICCFGR_CBS) >> 7);
+	cpuinfo->icache_size =
+	    cache_set_size * cpuinfo->icache_ways * cpuinfo->icache_block_size;
+
+	dccfgr = mfspr(SPR_DCCFGR);
+	cpuinfo->dcache_ways = 1 << (dccfgr & SPR_DCCFGR_NCW);
+	cache_set_size = 1 << ((dccfgr & SPR_DCCFGR_NCS) >> 3);
+	cpuinfo->dcache_block_size = 16 << ((dccfgr & SPR_DCCFGR_CBS) >> 7);
+	cpuinfo->dcache_size =
+	    cache_set_size * cpuinfo->dcache_ways * cpuinfo->dcache_block_size;
+
+	if (of_property_read_u32(cpu, "clock-frequency",
+				 &cpuinfo->clock_frequency)) {
+		printk(KERN_WARNING
+		       "Device tree missing CPU 'clock-frequency' parameter."
+		       "Assuming frequency 25MHZ"
+		       "This is probably not what you want.");
+	}
+
+	cpuinfo->coreid = mfspr(SPR_COREID);
+
+	of_node_put(cpu);
+
+	print_cpuinfo();
+}
+
+/**
+ * or32_early_setup
+ *
+ * Handles the pointer to the device tree that this kernel is to use
+ * for establishing the available platform devices.
+ *
+ * Falls back on built-in device tree in case null pointer is passed.
+ */
+
+void __init or32_early_setup(void *fdt)
+{
+	if (fdt)
+		pr_info("FDT at %p\n", fdt);
+	else {
+		fdt = __dtb_start;
+		pr_info("Compiled-in FDT at %p\n", fdt);
+	}
+	early_init_devtree(fdt);
+}
+
+static inline unsigned long extract_value_bits(unsigned long reg,
+					       short bit_nr, short width)
+{
+	return (reg >> bit_nr) & (0 << width);
+}
+
+static inline unsigned long extract_value(unsigned long reg, unsigned long mask)
+{
+	while (!(mask & 0x1)) {
+		reg = reg >> 1;
+		mask = mask >> 1;
+	}
+	return mask & reg;
+}
+
+void __init detect_unit_config(unsigned long upr, unsigned long mask,
+			       char *text, void (*func) (void))
+{
+	if (text != NULL)
+		printk("%s", text);
+
+	if (upr & mask) {
+		if (func != NULL)
+			func();
+		else
+			printk("present\n");
+	} else
+		printk("not present\n");
+}
+
+/*
+ * calibrate_delay
+ *
+ * Lightweight calibrate_delay implementation that calculates loops_per_jiffy
+ * from the clock frequency passed in via the device tree
+ *
+ */
+
+void calibrate_delay(void)
+{
+	const int *val;
+	struct device_node *cpu = setup_find_cpu_node(smp_processor_id());
+
+	val = of_get_property(cpu, "clock-frequency", NULL);
+	if (!val)
+		panic("no cpu 'clock-frequency' parameter in device tree");
+	loops_per_jiffy = *val / HZ;
+	pr_cont("%lu.%02lu BogoMIPS (lpj=%lu)\n",
+		loops_per_jiffy / (500000 / HZ),
+		(loops_per_jiffy / (5000 / HZ)) % 100, loops_per_jiffy);
+}
+
+void __init setup_arch(char **cmdline_p)
+{
+	unflatten_and_copy_device_tree();
+
+	setup_cpuinfo();
+
+#ifdef CONFIG_SMP
+	smp_init_cpus();
+#endif
+
+	/* process 1's initial memory region is the kernel code/data */
+	init_mm.start_code = (unsigned long)_stext;
+	init_mm.end_code = (unsigned long)_etext;
+	init_mm.end_data = (unsigned long)_edata;
+	init_mm.brk = (unsigned long)_end;
+
+#ifdef CONFIG_BLK_DEV_INITRD
+	initrd_start = (unsigned long)&__initrd_start;
+	initrd_end = (unsigned long)&__initrd_end;
+	if (initrd_start == initrd_end) {
+		initrd_start = 0;
+		initrd_end = 0;
+	}
+	initrd_below_start_ok = 1;
+#endif
+
+	/* setup memblock allocator */
+	setup_memory();
+
+	/* paging_init() sets up the MMU and marks all pages as reserved */
+	paging_init();
+
+#if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
+	if (!conswitchp)
+		conswitchp = &dummy_con;
+#endif
+
+	*cmdline_p = boot_command_line;
+
+	printk(KERN_INFO "OpenRISC Linux -- http://openrisc.io\n");
+}
+
+static int show_cpuinfo(struct seq_file *m, void *v)
+{
+	unsigned int vr, cpucfgr;
+	unsigned int avr;
+	unsigned int version;
+	struct cpuinfo_or1k *cpuinfo = v;
+
+	vr = mfspr(SPR_VR);
+	cpucfgr = mfspr(SPR_CPUCFGR);
+
+#ifdef CONFIG_SMP
+	seq_printf(m, "processor\t\t: %d\n", cpuinfo->coreid);
+#endif
+	if (vr & SPR_VR_UVRP) {
+		vr = mfspr(SPR_VR2);
+		version = vr & SPR_VR2_VER;
+		avr = mfspr(SPR_AVR);
+		seq_printf(m, "cpu architecture\t: "
+			   "OpenRISC 1000 (%d.%d-rev%d)\n",
+			   (avr >> 24) & 0xff,
+			   (avr >> 16) & 0xff,
+			   (avr >> 8) & 0xff);
+		seq_printf(m, "cpu implementation id\t: 0x%x\n",
+			   (vr & SPR_VR2_CPUID) >> 24);
+		seq_printf(m, "cpu version\t\t: 0x%x\n", version);
+	} else {
+		version = (vr & SPR_VR_VER) >> 24;
+		seq_printf(m, "cpu\t\t\t: OpenRISC-%x\n", version);
+		seq_printf(m, "revision\t\t: %d\n", vr & SPR_VR_REV);
+	}
+	seq_printf(m, "frequency\t\t: %ld\n", loops_per_jiffy * HZ);
+	seq_printf(m, "dcache size\t\t: %d bytes\n", cpuinfo->dcache_size);
+	seq_printf(m, "dcache block size\t: %d bytes\n",
+		   cpuinfo->dcache_block_size);
+	seq_printf(m, "dcache ways\t\t: %d\n", cpuinfo->dcache_ways);
+	seq_printf(m, "icache size\t\t: %d bytes\n", cpuinfo->icache_size);
+	seq_printf(m, "icache block size\t: %d bytes\n",
+		   cpuinfo->icache_block_size);
+	seq_printf(m, "icache ways\t\t: %d\n", cpuinfo->icache_ways);
+	seq_printf(m, "immu\t\t\t: %d entries, %lu ways\n",
+		   1 << ((mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTS) >> 2),
+		   1 + (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_NTW));
+	seq_printf(m, "dmmu\t\t\t: %d entries, %lu ways\n",
+		   1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> 2),
+		   1 + (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTW));
+	seq_printf(m, "bogomips\t\t: %lu.%02lu\n",
+		   (loops_per_jiffy * HZ) / 500000,
+		   ((loops_per_jiffy * HZ) / 5000) % 100);
+
+	seq_puts(m, "features\t\t: ");
+	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OB32S ? "orbis32" : "");
+	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OB64S ? "orbis64" : "");
+	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OF32S ? "orfpx32" : "");
+	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OF64S ? "orfpx64" : "");
+	seq_printf(m, "%s ", cpucfgr & SPR_CPUCFGR_OV64S ? "orvdx64" : "");
+	seq_puts(m, "\n");
+
+	seq_puts(m, "\n");
+
+	return 0;
+}
+
+static void *c_start(struct seq_file *m, loff_t *pos)
+{
+	*pos = cpumask_next(*pos - 1, cpu_online_mask);
+	if ((*pos) < nr_cpu_ids)
+		return &cpuinfo_or1k[*pos];
+	return NULL;
+}
+
+static void *c_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	(*pos)++;
+	return c_start(m, pos);
+}
+
+static void c_stop(struct seq_file *m, void *v)
+{
+}
+
+const struct seq_operations cpuinfo_op = {
+	.start = c_start,
+	.next = c_next,
+	.stop = c_stop,
+	.show = show_cpuinfo,
+};
diff --git a/arch/openrisc/kernel/signal.c b/arch/openrisc/kernel/signal.c
new file mode 100644
index 0000000..265f10f
--- /dev/null
+++ b/arch/openrisc/kernel/signal.c
@@ -0,0 +1,326 @@
+/*
+ * OpenRISC signal.c
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/tracehook.h>
+
+#include <asm/processor.h>
+#include <asm/syscall.h>
+#include <asm/ucontext.h>
+#include <linux/uaccess.h>
+
+#define DEBUG_SIG 0
+
+struct rt_sigframe {
+	struct siginfo info;
+	struct ucontext uc;
+	unsigned char retcode[16];	/* trampoline code */
+};
+
+static int restore_sigcontext(struct pt_regs *regs,
+			      struct sigcontext __user *sc)
+{
+	int err = 0;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	/*
+	 * Restore the regs from &sc->regs.
+	 * (sc is already checked for VERIFY_READ since the sigframe was
+	 *  checked in sys_sigreturn previously)
+	 */
+	err |= __copy_from_user(regs, sc->regs.gpr, 32 * sizeof(unsigned long));
+	err |= __copy_from_user(&regs->pc, &sc->regs.pc, sizeof(unsigned long));
+	err |= __copy_from_user(&regs->sr, &sc->regs.sr, sizeof(unsigned long));
+
+	/* make sure the SM-bit is cleared so user-mode cannot fool us */
+	regs->sr &= ~SPR_SR_SM;
+
+	regs->orig_gpr11 = -1;	/* Avoid syscall restart checks */
+
+	/* TODO: the other ports use regs->orig_XX to disable syscall checks
+	 * after this completes, but we don't use that mechanism. maybe we can
+	 * use it now ?
+	 */
+
+	return err;
+}
+
+asmlinkage long _sys_rt_sigreturn(struct pt_regs *regs)
+{
+	struct rt_sigframe *frame = (struct rt_sigframe __user *)regs->sp;
+	sigset_t set;
+
+	/*
+	 * Since we stacked the signal on a dword boundary,
+	 * then frame should be dword aligned here.  If it's
+	 * not, then the user is trying to mess with us.
+	 */
+	if (((long)frame) & 3)
+		goto badframe;
+
+	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+		goto badframe;
+	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+		goto badframe;
+
+	set_current_blocked(&set);
+
+	if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
+		goto badframe;
+
+	if (restore_altstack(&frame->uc.uc_stack))
+		goto badframe;
+
+	return regs->gpr[11];
+
+badframe:
+	force_sig(SIGSEGV, current);
+	return 0;
+}
+
+/*
+ * Set up a signal frame.
+ */
+
+static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+	int err = 0;
+
+	/* copy the regs */
+	/* There should be no need to save callee-saved registers here...
+	 * ...but we save them anyway.  Revisit this
+	 */
+	err |= __copy_to_user(sc->regs.gpr, regs, 32 * sizeof(unsigned long));
+	err |= __copy_to_user(&sc->regs.pc, &regs->pc, sizeof(unsigned long));
+	err |= __copy_to_user(&sc->regs.sr, &regs->sr, sizeof(unsigned long));
+
+	return err;
+}
+
+static inline unsigned long align_sigframe(unsigned long sp)
+{
+	return sp & ~3UL;
+}
+
+/*
+ * Work out where the signal frame should go.  It's either on the user stack
+ * or the alternate stack.
+ */
+
+static inline void __user *get_sigframe(struct ksignal *ksig,
+					struct pt_regs *regs, size_t frame_size)
+{
+	unsigned long sp = regs->sp;
+
+	/* redzone */
+	sp -= STACK_FRAME_OVERHEAD;
+	sp = sigsp(sp, ksig);
+	sp = align_sigframe(sp - frame_size);
+
+	return (void __user *)sp;
+}
+
+/* grab and setup a signal frame.
+ *
+ * basically we stack a lot of state info, and arrange for the
+ * user-mode program to return to the kernel using either a
+ * trampoline which performs the syscall sigreturn, or a provided
+ * user-mode trampoline.
+ */
+static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
+			  struct pt_regs *regs)
+{
+	struct rt_sigframe *frame;
+	unsigned long return_ip;
+	int err = 0;
+
+	frame = get_sigframe(ksig, regs, sizeof(*frame));
+
+	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+		return -EFAULT;
+
+	/* Create siginfo.  */
+	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
+		err |= copy_siginfo_to_user(&frame->info, &ksig->info);
+
+	/* Create the ucontext.  */
+	err |= __put_user(0, &frame->uc.uc_flags);
+	err |= __put_user(NULL, &frame->uc.uc_link);
+	err |= __save_altstack(&frame->uc.uc_stack, regs->sp);
+	err |= setup_sigcontext(regs, &frame->uc.uc_mcontext);
+
+	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
+	if (err)
+		return -EFAULT;
+
+	/* trampoline - the desired return ip is the retcode itself */
+	return_ip = (unsigned long)&frame->retcode;
+	/* This is:
+		l.ori r11,r0,__NR_sigreturn
+		l.sys 1
+	 */
+	err |= __put_user(0xa960,             (short *)(frame->retcode + 0));
+	err |= __put_user(__NR_rt_sigreturn,  (short *)(frame->retcode + 2));
+	err |= __put_user(0x20000001, (unsigned long *)(frame->retcode + 4));
+	err |= __put_user(0x15000000, (unsigned long *)(frame->retcode + 8));
+
+	if (err)
+		return -EFAULT;
+
+	/* Set up registers for signal handler */
+	regs->pc = (unsigned long)ksig->ka.sa.sa_handler; /* what we enter NOW */
+	regs->gpr[9] = (unsigned long)return_ip;     /* what we enter LATER */
+	regs->gpr[3] = (unsigned long)ksig->sig;           /* arg 1: signo */
+	regs->gpr[4] = (unsigned long)&frame->info;  /* arg 2: (siginfo_t*) */
+	regs->gpr[5] = (unsigned long)&frame->uc;    /* arg 3: ucontext */
+
+	/* actually move the usp to reflect the stacked frame */
+	regs->sp = (unsigned long)frame;
+
+	return 0;
+}
+
+static inline void
+handle_signal(struct ksignal *ksig, struct pt_regs *regs)
+{
+	int ret;
+
+	ret = setup_rt_frame(ksig, sigmask_to_save(), regs);
+
+	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
+}
+
+/*
+ * Note that 'init' is a special process: it doesn't get signals it doesn't
+ * want to handle. Thus you cannot kill init even with a SIGKILL even by
+ * mistake.
+ *
+ * Also note that the regs structure given here as an argument, is the latest
+ * pushed pt_regs. It may or may not be the same as the first pushed registers
+ * when the initial usermode->kernelmode transition took place. Therefore
+ * we can use user_mode(regs) to see if we came directly from kernel or user
+ * mode below.
+ */
+
+int do_signal(struct pt_regs *regs, int syscall)
+{
+	struct ksignal ksig;
+	unsigned long continue_addr = 0;
+	unsigned long restart_addr = 0;
+	unsigned long retval = 0;
+	int restart = 0;
+
+	if (syscall) {
+		continue_addr = regs->pc;
+		restart_addr = continue_addr - 4;
+		retval = regs->gpr[11];
+
+		/*
+		 * Setup syscall restart here so that a debugger will
+		 * see the already changed PC.
+		 */
+		switch (retval) {
+		case -ERESTART_RESTARTBLOCK:
+			restart = -2;
+			/* Fall through */
+		case -ERESTARTNOHAND:
+		case -ERESTARTSYS:
+		case -ERESTARTNOINTR:
+			restart++;
+			regs->gpr[11] = regs->orig_gpr11;
+			regs->pc = restart_addr;
+			break;
+		}
+	}
+
+	/*
+	 * Get the signal to deliver.  During the call to get_signal the
+	 * debugger may change all our registers so we may need to revert
+	 * the decision to restart the syscall; specifically, if the PC is
+	 * changed, don't restart the syscall.
+	 */
+	if (get_signal(&ksig)) {
+		if (unlikely(restart) && regs->pc == restart_addr) {
+			if (retval == -ERESTARTNOHAND ||
+			    retval == -ERESTART_RESTARTBLOCK
+			    || (retval == -ERESTARTSYS
+			        && !(ksig.ka.sa.sa_flags & SA_RESTART))) {
+				/* No automatic restart */
+				regs->gpr[11] = -EINTR;
+				regs->pc = continue_addr;
+			}
+		}
+		handle_signal(&ksig, regs);
+	} else {
+		/* no handler */
+		restore_saved_sigmask();
+		/*
+		 * Restore pt_regs PC as syscall restart will be handled by
+		 * kernel without return to userspace
+		 */
+		if (unlikely(restart) && regs->pc == restart_addr) {
+			regs->pc = continue_addr;
+			return restart;
+		}
+	}
+
+	return 0;
+}
+
+asmlinkage int
+do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
+{
+	do {
+		if (likely(thread_flags & _TIF_NEED_RESCHED)) {
+			schedule();
+		} else {
+			if (unlikely(!user_mode(regs)))
+				return 0;
+			local_irq_enable();
+			if (thread_flags & _TIF_SIGPENDING) {
+				int restart = do_signal(regs, syscall);
+				if (unlikely(restart)) {
+					/*
+					 * Restart without handlers.
+					 * Deal with it without leaving
+					 * the kernel space.
+					 */
+					return restart;
+				}
+				syscall = 0;
+			} else {
+				clear_thread_flag(TIF_NOTIFY_RESUME);
+				tracehook_notify_resume(regs);
+			}
+		}
+		local_irq_disable();
+		thread_flags = current_thread_info()->flags;
+	} while (thread_flags & _TIF_WORK_MASK);
+	return 0;
+}
diff --git a/arch/openrisc/kernel/smp.c b/arch/openrisc/kernel/smp.c
new file mode 100644
index 0000000..7d518ee
--- /dev/null
+++ b/arch/openrisc/kernel/smp.c
@@ -0,0 +1,259 @@
+/*
+ * Copyright (C) 2014 Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
+ * Copyright (C) 2017 Stafford Horne <shorne@gmail.com>
+ *
+ * Based on arm64 and arc implementations
+ * Copyright (C) 2013 ARM Ltd.
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2.  This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/smp.h>
+#include <linux/cpu.h>
+#include <linux/sched.h>
+#include <linux/irq.h>
+#include <asm/cpuinfo.h>
+#include <asm/mmu_context.h>
+#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
+#include <asm/time.h>
+
+static void (*smp_cross_call)(const struct cpumask *, unsigned int);
+
+unsigned long secondary_release = -1;
+struct thread_info *secondary_thread_info;
+
+enum ipi_msg_type {
+	IPI_WAKEUP,
+	IPI_RESCHEDULE,
+	IPI_CALL_FUNC,
+	IPI_CALL_FUNC_SINGLE,
+};
+
+static DEFINE_SPINLOCK(boot_lock);
+
+static void boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+	/*
+	 * set synchronisation state between this boot processor
+	 * and the secondary one
+	 */
+	spin_lock(&boot_lock);
+
+	secondary_release = cpu;
+	smp_cross_call(cpumask_of(cpu), IPI_WAKEUP);
+
+	/*
+	 * now the secondary core is starting up let it run its
+	 * calibrations, then wait for it to finish
+	 */
+	spin_unlock(&boot_lock);
+}
+
+void __init smp_prepare_boot_cpu(void)
+{
+}
+
+void __init smp_init_cpus(void)
+{
+	int i;
+
+	for (i = 0; i < NR_CPUS; i++)
+		set_cpu_possible(i, true);
+}
+
+void __init smp_prepare_cpus(unsigned int max_cpus)
+{
+	int i;
+
+	/*
+	 * Initialise the present map, which describes the set of CPUs
+	 * actually populated at the present time.
+	 */
+	for (i = 0; i < max_cpus; i++)
+		set_cpu_present(i, true);
+}
+
+void __init smp_cpus_done(unsigned int max_cpus)
+{
+}
+
+static DECLARE_COMPLETION(cpu_running);
+
+int __cpu_up(unsigned int cpu, struct task_struct *idle)
+{
+	if (smp_cross_call == NULL) {
+		pr_warn("CPU%u: failed to start, IPI controller missing",
+			cpu);
+		return -EIO;
+	}
+
+	secondary_thread_info = task_thread_info(idle);
+	current_pgd[cpu] = init_mm.pgd;
+
+	boot_secondary(cpu, idle);
+	if (!wait_for_completion_timeout(&cpu_running,
+					msecs_to_jiffies(1000))) {
+		pr_crit("CPU%u: failed to start\n", cpu);
+		return -EIO;
+	}
+	synchronise_count_master(cpu);
+
+	return 0;
+}
+
+asmlinkage __init void secondary_start_kernel(void)
+{
+	struct mm_struct *mm = &init_mm;
+	unsigned int cpu = smp_processor_id();
+	/*
+	 * All kernel threads share the same mm context; grab a
+	 * reference and switch to it.
+	 */
+	atomic_inc(&mm->mm_count);
+	current->active_mm = mm;
+	cpumask_set_cpu(cpu, mm_cpumask(mm));
+
+	pr_info("CPU%u: Booted secondary processor\n", cpu);
+
+	setup_cpuinfo();
+	openrisc_clockevent_init();
+
+	notify_cpu_starting(cpu);
+
+	/*
+	 * OK, now it's safe to let the boot CPU continue
+	 */
+	complete(&cpu_running);
+
+	synchronise_count_slave(cpu);
+	set_cpu_online(cpu, true);
+
+	local_irq_enable();
+
+	preempt_disable();
+	/*
+	 * OK, it's off to the idle thread for us
+	 */
+	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
+}
+
+void handle_IPI(unsigned int ipi_msg)
+{
+	unsigned int cpu = smp_processor_id();
+
+	switch (ipi_msg) {
+	case IPI_WAKEUP:
+		break;
+
+	case IPI_RESCHEDULE:
+		scheduler_ipi();
+		break;
+
+	case IPI_CALL_FUNC:
+		generic_smp_call_function_interrupt();
+		break;
+
+	case IPI_CALL_FUNC_SINGLE:
+		generic_smp_call_function_single_interrupt();
+		break;
+
+	default:
+		WARN(1, "CPU%u: Unknown IPI message 0x%x\n", cpu, ipi_msg);
+		break;
+	}
+}
+
+void smp_send_reschedule(int cpu)
+{
+	smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
+}
+
+static void stop_this_cpu(void *dummy)
+{
+	/* Remove this CPU */
+	set_cpu_online(smp_processor_id(), false);
+
+	local_irq_disable();
+	/* CPU Doze */
+	if (mfspr(SPR_UPR) & SPR_UPR_PMP)
+		mtspr(SPR_PMR, mfspr(SPR_PMR) | SPR_PMR_DME);
+	/* If that didn't work, infinite loop */
+	while (1)
+		;
+}
+
+void smp_send_stop(void)
+{
+	smp_call_function(stop_this_cpu, NULL, 0);
+}
+
+/* not supported, yet */
+int setup_profiling_timer(unsigned int multiplier)
+{
+	return -EINVAL;
+}
+
+void __init set_smp_cross_call(void (*fn)(const struct cpumask *, unsigned int))
+{
+	smp_cross_call = fn;
+}
+
+void arch_send_call_function_single_ipi(int cpu)
+{
+	smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
+}
+
+void arch_send_call_function_ipi_mask(const struct cpumask *mask)
+{
+	smp_cross_call(mask, IPI_CALL_FUNC);
+}
+
+/* TLB flush operations - Performed on each CPU*/
+static inline void ipi_flush_tlb_all(void *ignored)
+{
+	local_flush_tlb_all();
+}
+
+void flush_tlb_all(void)
+{
+	on_each_cpu(ipi_flush_tlb_all, NULL, 1);
+}
+
+/*
+ * FIXME: implement proper functionality instead of flush_tlb_all.
+ * *But*, as things currently stands, the local_tlb_flush_* functions will
+ * all boil down to local_tlb_flush_all anyway.
+ */
+void flush_tlb_mm(struct mm_struct *mm)
+{
+	on_each_cpu(ipi_flush_tlb_all, NULL, 1);
+}
+
+void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
+{
+	on_each_cpu(ipi_flush_tlb_all, NULL, 1);
+}
+
+void flush_tlb_range(struct vm_area_struct *vma,
+		     unsigned long start, unsigned long end)
+{
+	on_each_cpu(ipi_flush_tlb_all, NULL, 1);
+}
+
+/* Instruction cache invalidate - performed on each cpu */
+static void ipi_icache_page_inv(void *arg)
+{
+	struct page *page = arg;
+
+	local_icache_page_inv(page);
+}
+
+void smp_icache_page_inv(struct page *page)
+{
+	on_each_cpu(ipi_icache_page_inv, page, 1);
+}
+EXPORT_SYMBOL(smp_icache_page_inv);
diff --git a/arch/openrisc/kernel/stacktrace.c b/arch/openrisc/kernel/stacktrace.c
new file mode 100644
index 0000000..43f140a
--- /dev/null
+++ b/arch/openrisc/kernel/stacktrace.c
@@ -0,0 +1,86 @@
+/*
+ * Stack trace utility for OpenRISC
+ *
+ * Copyright (C) 2017 Stafford Horne <shorne@gmail.com>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2.  This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ *
+ * Losely based on work from sh and powerpc.
+ */
+
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/stacktrace.h>
+
+#include <asm/processor.h>
+#include <asm/unwinder.h>
+
+/*
+ * Save stack-backtrace addresses into a stack_trace buffer.
+ */
+static void
+save_stack_address(void *data, unsigned long addr, int reliable)
+{
+	struct stack_trace *trace = data;
+
+	if (!reliable)
+		return;
+
+	if (trace->skip > 0) {
+		trace->skip--;
+		return;
+	}
+
+	if (trace->nr_entries < trace->max_entries)
+		trace->entries[trace->nr_entries++] = addr;
+}
+
+void save_stack_trace(struct stack_trace *trace)
+{
+	unwind_stack(trace, (unsigned long *) &trace, save_stack_address);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);
+
+static void
+save_stack_address_nosched(void *data, unsigned long addr, int reliable)
+{
+	struct stack_trace *trace = (struct stack_trace *)data;
+
+	if (!reliable)
+		return;
+
+	if (in_sched_functions(addr))
+		return;
+
+	if (trace->skip > 0) {
+		trace->skip--;
+		return;
+	}
+
+	if (trace->nr_entries < trace->max_entries)
+		trace->entries[trace->nr_entries++] = addr;
+}
+
+void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+	unsigned long *sp = NULL;
+
+	if (tsk == current)
+		sp = (unsigned long *) &sp;
+	else
+		sp = (unsigned long *) KSTK_ESP(tsk);
+
+	unwind_stack(trace, sp, save_stack_address_nosched);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
+
+void
+save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
+{
+	unwind_stack(trace, (unsigned long *) regs->sp,
+		     save_stack_address_nosched);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_regs);
diff --git a/arch/openrisc/kernel/sync-timer.c b/arch/openrisc/kernel/sync-timer.c
new file mode 100644
index 0000000..ed8d835
--- /dev/null
+++ b/arch/openrisc/kernel/sync-timer.c
@@ -0,0 +1,120 @@
+/*
+ * OR1K timer synchronisation
+ *
+ * Based on work from MIPS implementation.
+ *
+ * All CPUs will have their count registers synchronised to the CPU0 next time
+ * value. This can cause a small timewarp for CPU0. All other CPU's should
+ * not have done anything significant (but they may have had interrupts
+ * enabled briefly - prom_smp_finish() should not be responsible for enabling
+ * interrupts...)
+ */
+
+#include <linux/kernel.h>
+#include <linux/irqflags.h>
+#include <linux/cpumask.h>
+
+#include <asm/time.h>
+#include <asm/timex.h>
+#include <linux/atomic.h>
+#include <asm/barrier.h>
+
+#include <asm/spr.h>
+
+static unsigned int initcount;
+static atomic_t count_count_start = ATOMIC_INIT(0);
+static atomic_t count_count_stop = ATOMIC_INIT(0);
+
+#define COUNTON 100
+#define NR_LOOPS 3
+
+void synchronise_count_master(int cpu)
+{
+	int i;
+	unsigned long flags;
+
+	pr_info("Synchronize counters for CPU %u: ", cpu);
+
+	local_irq_save(flags);
+
+	/*
+	 * We loop a few times to get a primed instruction cache,
+	 * then the last pass is more or less synchronised and
+	 * the master and slaves each set their cycle counters to a known
+	 * value all at once. This reduces the chance of having random offsets
+	 * between the processors, and guarantees that the maximum
+	 * delay between the cycle counters is never bigger than
+	 * the latency of information-passing (cachelines) between
+	 * two CPUs.
+	 */
+
+	for (i = 0; i < NR_LOOPS; i++) {
+		/* slaves loop on '!= 2' */
+		while (atomic_read(&count_count_start) != 1)
+			mb();
+		atomic_set(&count_count_stop, 0);
+		smp_wmb();
+
+		/* Let the slave writes its count register */
+		atomic_inc(&count_count_start);
+
+		/* Count will be initialised to current timer */
+		if (i == 1)
+			initcount = get_cycles();
+
+		/*
+		 * Everyone initialises count in the last loop:
+		 */
+		if (i == NR_LOOPS-1)
+			openrisc_timer_set(initcount);
+
+		/*
+		 * Wait for slave to leave the synchronization point:
+		 */
+		while (atomic_read(&count_count_stop) != 1)
+			mb();
+		atomic_set(&count_count_start, 0);
+		smp_wmb();
+		atomic_inc(&count_count_stop);
+	}
+	/* Arrange for an interrupt in a short while */
+	openrisc_timer_set_next(COUNTON);
+
+	local_irq_restore(flags);
+
+	/*
+	 * i386 code reported the skew here, but the
+	 * count registers were almost certainly out of sync
+	 * so no point in alarming people
+	 */
+	pr_cont("done.\n");
+}
+
+void synchronise_count_slave(int cpu)
+{
+	int i;
+
+	/*
+	 * Not every cpu is online at the time this gets called,
+	 * so we first wait for the master to say everyone is ready
+	 */
+
+	for (i = 0; i < NR_LOOPS; i++) {
+		atomic_inc(&count_count_start);
+		while (atomic_read(&count_count_start) != 2)
+			mb();
+
+		/*
+		 * Everyone initialises count in the last loop:
+		 */
+		if (i == NR_LOOPS-1)
+			openrisc_timer_set(initcount);
+
+		atomic_inc(&count_count_stop);
+		while (atomic_read(&count_count_stop) != 2)
+			mb();
+	}
+	/* Arrange for an interrupt in a short while */
+	openrisc_timer_set_next(COUNTON);
+}
+#undef NR_LOOPS
diff --git a/arch/openrisc/kernel/sys_call_table.c b/arch/openrisc/kernel/sys_call_table.c
new file mode 100644
index 0000000..e1f8ce8
--- /dev/null
+++ b/arch/openrisc/kernel/sys_call_table.c
@@ -0,0 +1,28 @@
+/*
+ * OpenRISC sys_call_table.c
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/syscalls.h>
+#include <linux/signal.h>
+#include <linux/unistd.h>
+
+#include <asm/syscalls.h>
+
+#undef __SYSCALL
+#define __SYSCALL(nr, call) [nr] = (call),
+
+void *sys_call_table[__NR_syscalls] = {
+#include <asm/unistd.h>
+};
diff --git a/arch/openrisc/kernel/time.c b/arch/openrisc/kernel/time.c
new file mode 100644
index 0000000..6baecea
--- /dev/null
+++ b/arch/openrisc/kernel/time.c
@@ -0,0 +1,176 @@
+/*
+ * OpenRISC time.c
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <linux/interrupt.h>
+#include <linux/ftrace.h>
+
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+
+#include <asm/cpuinfo.h>
+
+/* Test the timer ticks to count, used in sync routine */
+inline void openrisc_timer_set(unsigned long count)
+{
+	mtspr(SPR_TTCR, count);
+}
+
+/* Set the timer to trigger in delta cycles */
+inline void openrisc_timer_set_next(unsigned long delta)
+{
+	u32 c;
+
+	/* Read 32-bit counter value, add delta, mask off the low 28 bits.
+	 * We're guaranteed delta won't be bigger than 28 bits because the
+	 * generic timekeeping code ensures that for us.
+	 */
+	c = mfspr(SPR_TTCR);
+	c += delta;
+	c &= SPR_TTMR_TP;
+
+	/* Set counter and enable interrupt.
+	 * Keep timer in continuous mode always.
+	 */
+	mtspr(SPR_TTMR, SPR_TTMR_CR | SPR_TTMR_IE | c);
+}
+
+static int openrisc_timer_set_next_event(unsigned long delta,
+					 struct clock_event_device *dev)
+{
+	openrisc_timer_set_next(delta);
+	return 0;
+}
+
+/* This is the clock event device based on the OR1K tick timer.
+ * As the timer is being used as a continuous clock-source (required for HR
+ * timers) we cannot enable the PERIODIC feature.  The tick timer can run using
+ * one-shot events, so no problem.
+ */
+DEFINE_PER_CPU(struct clock_event_device, clockevent_openrisc_timer);
+
+void openrisc_clockevent_init(void)
+{
+	unsigned int cpu = smp_processor_id();
+	struct clock_event_device *evt =
+		&per_cpu(clockevent_openrisc_timer, cpu);
+	struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[cpu];
+
+	mtspr(SPR_TTMR, SPR_TTMR_CR);
+
+#ifdef CONFIG_SMP
+	evt->broadcast = tick_broadcast;
+#endif
+	evt->name = "openrisc_timer_clockevent",
+	evt->features = CLOCK_EVT_FEAT_ONESHOT,
+	evt->rating = 300,
+	evt->set_next_event = openrisc_timer_set_next_event,
+
+	evt->cpumask = cpumask_of(cpu);
+
+	/* We only have 28 bits */
+	clockevents_config_and_register(evt, cpuinfo->clock_frequency,
+					100, 0x0fffffff);
+
+}
+
+static inline void timer_ack(void)
+{
+	/* Clear the IP bit and disable further interrupts */
+	/* This can be done very simply... we just need to keep the timer
+	   running, so just maintain the CR bits while clearing the rest
+	   of the register
+	 */
+	mtspr(SPR_TTMR, SPR_TTMR_CR);
+}
+
+/*
+ * The timer interrupt is mostly handled in generic code nowadays... this
+ * function just acknowledges the interrupt and fires the event handler that
+ * has been set on the clockevent device by the generic time management code.
+ *
+ * This function needs to be called by the timer exception handler and that's
+ * all the exception handler needs to do.
+ */
+
+irqreturn_t __irq_entry timer_interrupt(struct pt_regs *regs)
+{
+	struct pt_regs *old_regs = set_irq_regs(regs);
+	unsigned int cpu = smp_processor_id();
+	struct clock_event_device *evt =
+		&per_cpu(clockevent_openrisc_timer, cpu);
+
+	timer_ack();
+
+	/*
+	 * update_process_times() expects us to have called irq_enter().
+	 */
+	irq_enter();
+	evt->event_handler(evt);
+	irq_exit();
+
+	set_irq_regs(old_regs);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * Clocksource: Based on OpenRISC timer/counter
+ *
+ * This sets up the OpenRISC Tick Timer as a clock source.  The tick timer
+ * is 32 bits wide and runs at the CPU clock frequency.
+ */
+static u64 openrisc_timer_read(struct clocksource *cs)
+{
+	return (u64) mfspr(SPR_TTCR);
+}
+
+static struct clocksource openrisc_timer = {
+	.name = "openrisc_timer",
+	.rating = 200,
+	.read = openrisc_timer_read,
+	.mask = CLOCKSOURCE_MASK(32),
+	.flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int __init openrisc_timer_init(void)
+{
+	struct cpuinfo_or1k *cpuinfo = &cpuinfo_or1k[smp_processor_id()];
+
+	if (clocksource_register_hz(&openrisc_timer, cpuinfo->clock_frequency))
+		panic("failed to register clocksource");
+
+	/* Enable the incrementer: 'continuous' mode with interrupt disabled */
+	mtspr(SPR_TTMR, SPR_TTMR_CR);
+
+	return 0;
+}
+
+void __init time_init(void)
+{
+	u32 upr;
+
+	upr = mfspr(SPR_UPR);
+	if (!(upr & SPR_UPR_TTP))
+		panic("Linux not supported on devices without tick timer");
+
+	openrisc_timer_init();
+	openrisc_clockevent_init();
+}
diff --git a/arch/openrisc/kernel/traps.c b/arch/openrisc/kernel/traps.c
new file mode 100644
index 0000000..d8981cb
--- /dev/null
+++ b/arch/openrisc/kernel/traps.c
@@ -0,0 +1,477 @@
+/*
+ * OpenRISC traps.c
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ *
+ *  Here we handle the break vectors not used by the system call
+ *  mechanism, as well as some general stack/register dumping
+ *  things.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/task_stack.h>
+#include <linux/kernel.h>
+#include <linux/extable.h>
+#include <linux/kmod.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/timer.h>
+#include <linux/mm.h>
+#include <linux/kallsyms.h>
+#include <linux/uaccess.h>
+
+#include <asm/segment.h>
+#include <asm/io.h>
+#include <asm/pgtable.h>
+#include <asm/unwinder.h>
+#include <asm/sections.h>
+
+int kstack_depth_to_print = 0x180;
+int lwa_flag;
+unsigned long __user *lwa_addr;
+
+void print_trace(void *data, unsigned long addr, int reliable)
+{
+	pr_emerg("[<%p>] %s%pS\n", (void *) addr, reliable ? "" : "? ",
+	       (void *) addr);
+}
+
+/* displays a short stack trace */
+void show_stack(struct task_struct *task, unsigned long *esp)
+{
+	if (esp == NULL)
+		esp = (unsigned long *)&esp;
+
+	pr_emerg("Call trace:\n");
+	unwind_stack(NULL, esp, print_trace);
+}
+
+void show_trace_task(struct task_struct *tsk)
+{
+	/*
+	 * TODO: SysRq-T trace dump...
+	 */
+}
+
+void show_registers(struct pt_regs *regs)
+{
+	int i;
+	int in_kernel = 1;
+	unsigned long esp;
+
+	esp = (unsigned long)(regs->sp);
+	if (user_mode(regs))
+		in_kernel = 0;
+
+	printk("CPU #: %d\n"
+	       "   PC: %08lx    SR: %08lx    SP: %08lx\n",
+	       smp_processor_id(), regs->pc, regs->sr, regs->sp);
+	printk("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n",
+	       0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]);
+	printk("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n",
+	       regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]);
+	printk("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n",
+	       regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]);
+	printk("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n",
+	       regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]);
+	printk("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n",
+	       regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]);
+	printk("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n",
+	       regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]);
+	printk("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n",
+	       regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]);
+	printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n",
+	       regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]);
+	printk("  RES: %08lx oGPR11: %08lx\n",
+	       regs->gpr[11], regs->orig_gpr11);
+
+	printk("Process %s (pid: %d, stackpage=%08lx)\n",
+	       current->comm, current->pid, (unsigned long)current);
+	/*
+	 * When in-kernel, we also print out the stack and code at the
+	 * time of the fault..
+	 */
+	if (in_kernel) {
+
+		printk("\nStack: ");
+		show_stack(NULL, (unsigned long *)esp);
+
+		printk("\nCode: ");
+		if (regs->pc < PAGE_OFFSET)
+			goto bad;
+
+		for (i = -24; i < 24; i++) {
+			unsigned char c;
+			if (__get_user(c, &((unsigned char *)regs->pc)[i])) {
+bad:
+				printk(" Bad PC value.");
+				break;
+			}
+
+			if (i == 0)
+				printk("(%02x) ", c);
+			else
+				printk("%02x ", c);
+		}
+	}
+	printk("\n");
+}
+
+void nommu_dump_state(struct pt_regs *regs,
+		      unsigned long ea, unsigned long vector)
+{
+	int i;
+	unsigned long addr, stack = regs->sp;
+
+	printk("\n\r[nommu_dump_state] :: ea %lx, vector %lx\n\r", ea, vector);
+
+	printk("CPU #: %d\n"
+	       "   PC: %08lx    SR: %08lx    SP: %08lx\n",
+	       0, regs->pc, regs->sr, regs->sp);
+	printk("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n",
+	       0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]);
+	printk("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n",
+	       regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]);
+	printk("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n",
+	       regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]);
+	printk("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n",
+	       regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]);
+	printk("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n",
+	       regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]);
+	printk("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n",
+	       regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]);
+	printk("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n",
+	       regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]);
+	printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n",
+	       regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]);
+	printk("  RES: %08lx oGPR11: %08lx\n",
+	       regs->gpr[11], regs->orig_gpr11);
+
+	printk("Process %s (pid: %d, stackpage=%08lx)\n",
+	       ((struct task_struct *)(__pa(current)))->comm,
+	       ((struct task_struct *)(__pa(current)))->pid,
+	       (unsigned long)current);
+
+	printk("\nStack: ");
+	printk("Stack dump [0x%08lx]:\n", (unsigned long)stack);
+	for (i = 0; i < kstack_depth_to_print; i++) {
+		if (((long)stack & (THREAD_SIZE - 1)) == 0)
+			break;
+		stack++;
+
+		printk("%lx :: sp + %02d: 0x%08lx\n", stack, i * 4,
+		       *((unsigned long *)(__pa(stack))));
+	}
+	printk("\n");
+
+	printk("Call Trace:   ");
+	i = 1;
+	while (((long)stack & (THREAD_SIZE - 1)) != 0) {
+		addr = *((unsigned long *)__pa(stack));
+		stack++;
+
+		if (kernel_text_address(addr)) {
+			if (i && ((i % 6) == 0))
+				printk("\n ");
+			printk(" [<%08lx>]", addr);
+			i++;
+		}
+	}
+	printk("\n");
+
+	printk("\nCode: ");
+
+	for (i = -24; i < 24; i++) {
+		unsigned char c;
+		c = ((unsigned char *)(__pa(regs->pc)))[i];
+
+		if (i == 0)
+			printk("(%02x) ", c);
+		else
+			printk("%02x ", c);
+	}
+	printk("\n");
+}
+
+/* This is normally the 'Oops' routine */
+void die(const char *str, struct pt_regs *regs, long err)
+{
+
+	console_verbose();
+	printk("\n%s#: %04lx\n", str, err & 0xffff);
+	show_registers(regs);
+#ifdef CONFIG_JUMP_UPON_UNHANDLED_EXCEPTION
+	printk("\n\nUNHANDLED_EXCEPTION: entering infinite loop\n");
+
+	/* shut down interrupts */
+	local_irq_disable();
+
+	__asm__ __volatile__("l.nop   1");
+	do {} while (1);
+#endif
+	do_exit(SIGSEGV);
+}
+
+/* This is normally the 'Oops' routine */
+void die_if_kernel(const char *str, struct pt_regs *regs, long err)
+{
+	if (user_mode(regs))
+		return;
+
+	die(str, regs, err);
+}
+
+void unhandled_exception(struct pt_regs *regs, int ea, int vector)
+{
+	printk("Unable to handle exception at EA =0x%x, vector 0x%x",
+	       ea, vector);
+	die("Oops", regs, 9);
+}
+
+void __init trap_init(void)
+{
+	/* Nothing needs to be done */
+}
+
+asmlinkage void do_trap(struct pt_regs *regs, unsigned long address)
+{
+	force_sig_fault(SIGTRAP, TRAP_TRACE, (void __user *)address, current);
+
+	regs->pc += 4;
+}
+
+asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address)
+{
+	if (user_mode(regs)) {
+		/* Send a SIGBUS */
+		force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)address, current);
+	} else {
+		printk("KERNEL: Unaligned Access 0x%.8lx\n", address);
+		show_registers(regs);
+		die("Die:", regs, address);
+	}
+
+}
+
+asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address)
+{
+	if (user_mode(regs)) {
+		/* Send a SIGBUS */
+		force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address, current);
+	} else {		/* Kernel mode */
+		printk("KERNEL: Bus error (SIGBUS) 0x%.8lx\n", address);
+		show_registers(regs);
+		die("Die:", regs, address);
+	}
+}
+
+static inline int in_delay_slot(struct pt_regs *regs)
+{
+#ifdef CONFIG_OPENRISC_NO_SPR_SR_DSX
+	/* No delay slot flag, do the old way */
+	unsigned int op, insn;
+
+	insn = *((unsigned int *)regs->pc);
+	op = insn >> 26;
+	switch (op) {
+	case 0x00: /* l.j */
+	case 0x01: /* l.jal */
+	case 0x03: /* l.bnf */
+	case 0x04: /* l.bf */
+	case 0x11: /* l.jr */
+	case 0x12: /* l.jalr */
+		return 1;
+	default:
+		return 0;
+	}
+#else
+	return mfspr(SPR_SR) & SPR_SR_DSX;
+#endif
+}
+
+static inline void adjust_pc(struct pt_regs *regs, unsigned long address)
+{
+	int displacement;
+	unsigned int rb, op, jmp;
+
+	if (unlikely(in_delay_slot(regs))) {
+		/* In delay slot, instruction at pc is a branch, simulate it */
+		jmp = *((unsigned int *)regs->pc);
+
+		displacement = sign_extend32(((jmp) & 0x3ffffff) << 2, 27);
+		rb = (jmp & 0x0000ffff) >> 11;
+		op = jmp >> 26;
+
+		switch (op) {
+		case 0x00: /* l.j */
+			regs->pc += displacement;
+			return;
+		case 0x01: /* l.jal */
+			regs->pc += displacement;
+			regs->gpr[9] = regs->pc + 8;
+			return;
+		case 0x03: /* l.bnf */
+			if (regs->sr & SPR_SR_F)
+				regs->pc += 8;
+			else
+				regs->pc += displacement;
+			return;
+		case 0x04: /* l.bf */
+			if (regs->sr & SPR_SR_F)
+				regs->pc += displacement;
+			else
+				regs->pc += 8;
+			return;
+		case 0x11: /* l.jr */
+			regs->pc = regs->gpr[rb];
+			return;
+		case 0x12: /* l.jalr */
+			regs->pc = regs->gpr[rb];
+			regs->gpr[9] = regs->pc + 8;
+			return;
+		default:
+			break;
+		}
+	} else {
+		regs->pc += 4;
+	}
+}
+
+static inline void simulate_lwa(struct pt_regs *regs, unsigned long address,
+				unsigned int insn)
+{
+	unsigned int ra, rd;
+	unsigned long value;
+	unsigned long orig_pc;
+	long imm;
+
+	const struct exception_table_entry *entry;
+
+	orig_pc = regs->pc;
+	adjust_pc(regs, address);
+
+	ra = (insn >> 16) & 0x1f;
+	rd = (insn >> 21) & 0x1f;
+	imm = (short)insn;
+	lwa_addr = (unsigned long __user *)(regs->gpr[ra] + imm);
+
+	if ((unsigned long)lwa_addr & 0x3) {
+		do_unaligned_access(regs, address);
+		return;
+	}
+
+	if (get_user(value, lwa_addr)) {
+		if (user_mode(regs)) {
+			force_sig(SIGSEGV, current);
+			return;
+		}
+
+		if ((entry = search_exception_tables(orig_pc))) {
+			regs->pc = entry->fixup;
+			return;
+		}
+
+		/* kernel access in kernel space, load it directly */
+		value = *((unsigned long *)lwa_addr);
+	}
+
+	lwa_flag = 1;
+	regs->gpr[rd] = value;
+}
+
+static inline void simulate_swa(struct pt_regs *regs, unsigned long address,
+				unsigned int insn)
+{
+	unsigned long __user *vaddr;
+	unsigned long orig_pc;
+	unsigned int ra, rb;
+	long imm;
+
+	const struct exception_table_entry *entry;
+
+	orig_pc = regs->pc;
+	adjust_pc(regs, address);
+
+	ra = (insn >> 16) & 0x1f;
+	rb = (insn >> 11) & 0x1f;
+	imm = (short)(((insn & 0x2200000) >> 10) | (insn & 0x7ff));
+	vaddr = (unsigned long __user *)(regs->gpr[ra] + imm);
+
+	if (!lwa_flag || vaddr != lwa_addr) {
+		regs->sr &= ~SPR_SR_F;
+		return;
+	}
+
+	if ((unsigned long)vaddr & 0x3) {
+		do_unaligned_access(regs, address);
+		return;
+	}
+
+	if (put_user(regs->gpr[rb], vaddr)) {
+		if (user_mode(regs)) {
+			force_sig(SIGSEGV, current);
+			return;
+		}
+
+		if ((entry = search_exception_tables(orig_pc))) {
+			regs->pc = entry->fixup;
+			return;
+		}
+
+		/* kernel access in kernel space, store it directly */
+		*((unsigned long *)vaddr) = regs->gpr[rb];
+	}
+
+	lwa_flag = 0;
+	regs->sr |= SPR_SR_F;
+}
+
+#define INSN_LWA	0x1b
+#define INSN_SWA	0x33
+
+asmlinkage void do_illegal_instruction(struct pt_regs *regs,
+				       unsigned long address)
+{
+	unsigned int op;
+	unsigned int insn = *((unsigned int *)address);
+
+	op = insn >> 26;
+
+	switch (op) {
+	case INSN_LWA:
+		simulate_lwa(regs, address, insn);
+		return;
+
+	case INSN_SWA:
+		simulate_swa(regs, address, insn);
+		return;
+
+	default:
+		break;
+	}
+
+	if (user_mode(regs)) {
+		/* Send a SIGILL */
+		force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)address, current);
+	} else {		/* Kernel mode */
+		printk("KERNEL: Illegal instruction (SIGILL) 0x%.8lx\n",
+		       address);
+		show_registers(regs);
+		die("Die:", regs, address);
+	}
+}
diff --git a/arch/openrisc/kernel/unwinder.c b/arch/openrisc/kernel/unwinder.c
new file mode 100644
index 0000000..8ae15c2
--- /dev/null
+++ b/arch/openrisc/kernel/unwinder.c
@@ -0,0 +1,105 @@
+/*
+ * OpenRISC unwinder.c
+ *
+ * Reusable arch specific api for unwinding stacks.
+ *
+ * Copyright (C) 2017 Stafford Horne <shorne@gmail.com>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2.  This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/sched/task_stack.h>
+#include <linux/kernel.h>
+
+#include <asm/unwinder.h>
+
+#ifdef CONFIG_FRAME_POINTER
+struct or1k_frameinfo {
+	unsigned long *fp;
+	unsigned long ra;
+	unsigned long top;
+};
+
+/*
+ * Verify a frameinfo structure.  The return address should be a valid text
+ * address.  The frame pointer may be null if its the last frame, otherwise
+ * the frame pointer should point to a location in the stack after the the
+ * top of the next frame up.
+ */
+static inline int or1k_frameinfo_valid(struct or1k_frameinfo *frameinfo)
+{
+	return (frameinfo->fp == NULL ||
+		(!kstack_end(frameinfo->fp) &&
+		 frameinfo->fp > &frameinfo->top)) &&
+	       __kernel_text_address(frameinfo->ra);
+}
+
+/*
+ * Create a stack trace doing scanning which is frame pointer aware. We can
+ * get reliable stack traces by matching the previously found frame
+ * pointer with the top of the stack address every time we find a valid
+ * or1k_frameinfo.
+ *
+ * Ideally the stack parameter will be passed as FP, but it can not be
+ * guaranteed.  Therefore we scan each address looking for the first sign
+ * of a return address.
+ *
+ * The OpenRISC stack frame looks something like the following.  The
+ * location SP is held in r1 and location FP is held in r2 when frame pointers
+ * enabled.
+ *
+ * SP   -> (top of stack)
+ *      -  (callee saved registers)
+ *      -  (local variables)
+ * FP-8 -> previous FP             \
+ * FP-4 -> return address          |- or1k_frameinfo
+ * FP   -> (previous top of stack) /
+ */
+void unwind_stack(void *data, unsigned long *stack,
+		  void (*trace)(void *data, unsigned long addr, int reliable))
+{
+	unsigned long *next_fp = NULL;
+	struct or1k_frameinfo *frameinfo = NULL;
+	int reliable = 0;
+
+	while (!kstack_end(stack)) {
+		frameinfo = container_of(stack,
+					 struct or1k_frameinfo,
+					 top);
+
+		if (__kernel_text_address(frameinfo->ra)) {
+			if (or1k_frameinfo_valid(frameinfo) &&
+			    (next_fp == NULL ||
+			     next_fp == &frameinfo->top)) {
+				reliable = 1;
+				next_fp = frameinfo->fp;
+			} else
+				reliable = 0;
+
+			trace(data, frameinfo->ra, reliable);
+		}
+		stack++;
+	}
+}
+
+#else /* CONFIG_FRAME_POINTER */
+
+/*
+ * Create a stack trace by doing a simple scan treating all text addresses
+ * as return addresses.
+ */
+void unwind_stack(void *data, unsigned long *stack,
+		   void (*trace)(void *data, unsigned long addr, int reliable))
+{
+	unsigned long addr;
+
+	while (!kstack_end(stack)) {
+		addr = *stack++;
+		if (__kernel_text_address(addr))
+			trace(data, addr, 0);
+	}
+}
+#endif /* CONFIG_FRAME_POINTER */
+
diff --git a/arch/openrisc/kernel/vmlinux.h b/arch/openrisc/kernel/vmlinux.h
new file mode 100644
index 0000000..bdea46c
--- /dev/null
+++ b/arch/openrisc/kernel/vmlinux.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __OPENRISC_VMLINUX_H_
+#define __OPENRISC_VMLINUX_H_
+
+#ifdef CONFIG_BLK_DEV_INITRD
+extern char __initrd_start, __initrd_end;
+#endif
+
+#endif
diff --git a/arch/openrisc/kernel/vmlinux.lds.S b/arch/openrisc/kernel/vmlinux.lds.S
new file mode 100644
index 0000000..953bdcd
--- /dev/null
+++ b/arch/openrisc/kernel/vmlinux.lds.S
@@ -0,0 +1,126 @@
+/*
+ * OpenRISC vmlinux.lds.S
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ *
+ * ld script for OpenRISC architecture
+ */
+
+/* TODO
+ *		- clean up __offset & stuff
+ *		- change all 8192 alignment to PAGE !!!
+ *		- recheck if all alignments are really needed
+ */
+
+#  define LOAD_OFFSET  PAGE_OFFSET
+#  define LOAD_BASE    PAGE_OFFSET
+
+#include <asm/page.h>
+#include <asm/cache.h>
+#include <asm/thread_info.h>
+#include <asm-generic/vmlinux.lds.h>
+
+#ifdef __OR1K__
+#define __OUTPUT_FORMAT        "elf32-or1k"
+#else
+#define __OUTPUT_FORMAT        "elf32-or32"
+#endif
+
+OUTPUT_FORMAT(__OUTPUT_FORMAT, __OUTPUT_FORMAT, __OUTPUT_FORMAT)
+jiffies = jiffies_64 + 4;
+
+SECTIONS
+{
+        /* Read-only sections, merged into text segment: */
+        . = LOAD_BASE ;
+
+	_text = .;
+
+	/* _s_kernel_ro must be page aligned */
+	. = ALIGN(PAGE_SIZE);
+	_s_kernel_ro = .;
+
+        .text                   : AT(ADDR(.text) - LOAD_OFFSET)
+	{
+          _stext = .;
+	  TEXT_TEXT
+	  SCHED_TEXT
+	  CPUIDLE_TEXT
+	  LOCK_TEXT
+	  KPROBES_TEXT
+	  IRQENTRY_TEXT
+	  SOFTIRQENTRY_TEXT
+	  *(.fixup)
+	  *(.text.__*)
+	  _etext = .;
+	}
+	/* TODO: Check if fixup and text.__* are really necessary
+	 * fixup is definitely necessary
+	 */
+
+	_sdata = .;
+
+	/* Page alignment required for RO_DATA_SECTION */
+	RO_DATA_SECTION(PAGE_SIZE)
+	_e_kernel_ro = .;
+
+	/* Whatever comes after _e_kernel_ro had better be page-aligend, too */
+
+	/* 32 here is cacheline size... recheck this */
+	RW_DATA_SECTION(32, PAGE_SIZE, PAGE_SIZE)
+
+        _edata  =  .;
+
+	EXCEPTION_TABLE(4)
+	NOTES
+
+	/* Init code and data */
+	. = ALIGN(PAGE_SIZE);
+	__init_begin = .;
+
+	HEAD_TEXT_SECTION
+
+	/* Page aligned */
+	INIT_TEXT_SECTION(PAGE_SIZE)
+
+	/* Align __setup_start on 16 byte boundary */
+	INIT_DATA_SECTION(16)
+
+	PERCPU_SECTION(L1_CACHE_BYTES)
+
+        __init_end = .;
+
+	. = ALIGN(PAGE_SIZE);
+	.initrd			: AT(ADDR(.initrd) - LOAD_OFFSET)
+	{
+		__initrd_start = .;
+		*(.initrd)
+		__initrd_end = .;
+		FILL (0);
+                . = ALIGN (PAGE_SIZE);
+	}
+
+        __vmlinux_end = .;            /* last address of the physical file */
+
+	BSS_SECTION(0, 0, 0x20)
+
+        _end = .;
+
+	/* Throw in the debugging sections */
+	STABS_DEBUG
+	DWARF_DEBUG
+
+        /* Sections to be discarded -- must be last */
+	DISCARDS
+}