Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/firmware/efi/libstub/arm32-stub.c b/drivers/firmware/efi/libstub/arm32-stub.c
index becbda4..41213bf 100644
--- a/drivers/firmware/efi/libstub/arm32-stub.c
+++ b/drivers/firmware/efi/libstub/arm32-stub.c
@@ -1,10 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2013 Linaro Ltd;  <roy.franz@linaro.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
  */
 #include <linux/efi.h>
 #include <asm/efi.h>
@@ -199,6 +195,7 @@
 				 unsigned long dram_base,
 				 efi_loaded_image_t *image)
 {
+	unsigned long kernel_base;
 	efi_status_t status;
 
 	/*
@@ -208,9 +205,18 @@
 	 * loaded. These assumptions are made by the decompressor,
 	 * before any memory map is available.
 	 */
-	dram_base = round_up(dram_base, SZ_128M);
+	kernel_base = round_up(dram_base, SZ_128M);
 
-	status = reserve_kernel_base(sys_table, dram_base, reserve_addr,
+	/*
+	 * Note that some platforms (notably, the Raspberry Pi 2) put
+	 * spin-tables and other pieces of firmware at the base of RAM,
+	 * abusing the fact that the window of TEXT_OFFSET bytes at the
+	 * base of the kernel image is only partially used at the moment.
+	 * (Up to 5 pages are used for the swapper page tables)
+	 */
+	kernel_base += TEXT_OFFSET - 5 * PAGE_SIZE;
+
+	status = reserve_kernel_base(sys_table, kernel_base, reserve_addr,
 				     reserve_size);
 	if (status != EFI_SUCCESS) {
 		pr_efi_err(sys_table, "Unable to allocate memory for uncompressed kernel.\n");
@@ -224,7 +230,7 @@
 	*image_size = image->image_size;
 	status = efi_relocate_kernel(sys_table, image_addr, *image_size,
 				     *image_size,
-				     dram_base + MAX_UNCOMP_KERNEL_SIZE, 0);
+				     kernel_base + MAX_UNCOMP_KERNEL_SIZE, 0, 0);
 	if (status != EFI_SUCCESS) {
 		pr_efi_err(sys_table, "Failed to relocate kernel.\n");
 		efi_free(sys_table, *reserve_size, *reserve_addr);