rework general purpose registers save and restore
The runtime exception handling assembler code used magic numbers for
saving and restoring the general purpose register context on stack
memory. The memory is interpreted as a 'gp_regs' structure and the
magic numbers are offsets to members of this structure. This patch
replaces the magic number offsets with constants. It also adds compile
time assertions to prevent an incorrect assembler view of this
structure.
Change-Id: Ibf125bfdd62ba3a33e58c5f1d71f8c229720781c
diff --git a/lib/arch/aarch64/misc_helpers.S b/lib/arch/aarch64/misc_helpers.S
index 08a568e..c951d0e 100644
--- a/lib/arch/aarch64/misc_helpers.S
+++ b/lib/arch/aarch64/misc_helpers.S
@@ -29,6 +29,10 @@
*/
#include <arch_helpers.h>
+#include <runtime_svc.h>
+
+ .globl save_regs
+ .globl restore_regs
.globl enable_irq
.globl disable_irq
@@ -80,6 +84,51 @@
.section .text, "ax"
+save_regs:; .type save_regs, %function
+ sub sp, sp, #GPREGS_FP_OFF
+ stp x0, x1, [sp, #GPREGS_X0_OFF]
+ stp x2, x3, [sp, #GPREGS_X2_OFF]
+ stp x4, x5, [sp, #GPREGS_X4_OFF]
+ stp x6, x7, [sp, #GPREGS_X6_OFF]
+ stp x8, x9, [sp, #GPREGS_X8_OFF]
+ stp x10, x11, [sp, #GPREGS_X10_OFF]
+ stp x12, x13, [sp, #GPREGS_X12_OFF]
+ stp x14, x15, [sp, #GPREGS_X14_OFF]
+ stp x16, x17, [sp, #GPREGS_X16_OFF]
+ stp x18, x19, [sp, #GPREGS_X18_OFF]
+ stp x20, x21, [sp, #GPREGS_X20_OFF]
+ stp x22, x23, [sp, #GPREGS_X22_OFF]
+ stp x24, x25, [sp, #GPREGS_X24_OFF]
+ stp x26, x27, [sp, #GPREGS_X26_OFF]
+ mrs x0, sp_el0
+ stp x28, x0, [sp, #GPREGS_X28_OFF]
+ mrs x0, spsr_el3
+ str x0, [sp, #GPREGS_SPSR_OFF]
+ ret
+
+
+restore_regs:; .type restore_regs, %function
+ ldr x9, [sp, #GPREGS_SPSR_OFF]
+ msr spsr_el3, x9
+ ldp x28, x9, [sp, #GPREGS_X28_OFF]
+ msr sp_el0, x9
+ ldp x26, x27, [sp, #GPREGS_X26_OFF]
+ ldp x24, x25, [sp, #GPREGS_X24_OFF]
+ ldp x22, x23, [sp, #GPREGS_X22_OFF]
+ ldp x20, x21, [sp, #GPREGS_X20_OFF]
+ ldp x18, x19, [sp, #GPREGS_X18_OFF]
+ ldp x16, x17, [sp, #GPREGS_X16_OFF]
+ ldp x14, x15, [sp, #GPREGS_X14_OFF]
+ ldp x12, x13, [sp, #GPREGS_X12_OFF]
+ ldp x10, x11, [sp, #GPREGS_X10_OFF]
+ ldp x8, x9, [sp, #GPREGS_X8_OFF]
+ ldp x6, x7, [sp, #GPREGS_X6_OFF]
+ ldp x4, x5, [sp, #GPREGS_X4_OFF]
+ ldp x2, x3, [sp, #GPREGS_X2_OFF]
+ ldp x0, x1, [sp, #GPREGS_X0_OFF]
+ add sp, sp, #GPREGS_FP_OFF
+ ret
+
get_afflvl_shift:; .type get_afflvl_shift, %function
cmp x0, #3
cinc x0, x0, eq