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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2015-10-23 17:48:14 +0300
committerCatalin Marinas <catalin.marinas@arm.com>2015-10-30 19:02:52 +0300
commitbf457786f569cc480629d7855cac1fd1173ac009 (patch)
treef4f2eea9505db363050ae55eb80b2317b2446eb9 /drivers/firmware
parentcb083816ab5ac3d10a9417527f07fc5962cc3808 (diff)
downloadlinux-bf457786f569cc480629d7855cac1fd1173ac009.tar.xz
arm64/efi: move arm64 specific stub C code to libstub
Now that we added special handling to the C files in libstub, move the one remaining arm64 specific EFI stub C file to libstub as well, so that it gets the same treatment. This should prevent future changes from resulting in binaries that may execute incorrectly in UEFI context. With efi-entry.S the only remaining EFI stub source file under arch/arm64, we can also simplify the Makefile logic somewhat. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'drivers/firmware')
-rw-r--r--drivers/firmware/efi/libstub/Makefile3
-rw-r--r--drivers/firmware/efi/libstub/arm64-stub.c68
2 files changed, 71 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index bca9a76cbd33..92ae557abbbc 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -34,6 +34,9 @@ $(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o string.o \
$(patsubst %.c,lib-%.o,$(arm-deps))
+lib-$(CONFIG_ARM64) += arm64-stub.o
+CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
+
#
# arm64 puts the stub in the kernel proper, which will unnecessarily retain all
# code indefinitely unless it is annotated as __init/__initdata/__initconst etc.
diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c
new file mode 100644
index 000000000000..816120ece6bc
--- /dev/null
+++ b/drivers/firmware/efi/libstub/arm64-stub.c
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2013, 2014 Linaro Ltd; <roy.franz@linaro.org>
+ *
+ * This file implements the EFI boot stub for the arm64 kernel.
+ * Adapted from ARM version by Mark Salter <msalter@redhat.com>
+ *
+ * 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>
+#include <asm/sections.h>
+
+efi_status_t __init handle_kernel_image(efi_system_table_t *sys_table_arg,
+ unsigned long *image_addr,
+ unsigned long *image_size,
+ unsigned long *reserve_addr,
+ unsigned long *reserve_size,
+ unsigned long dram_base,
+ efi_loaded_image_t *image)
+{
+ efi_status_t status;
+ unsigned long kernel_size, kernel_memsize = 0;
+ unsigned long nr_pages;
+ void *old_image_addr = (void *)*image_addr;
+
+ /* Relocate the image, if required. */
+ kernel_size = _edata - _text;
+ if (*image_addr != (dram_base + TEXT_OFFSET)) {
+ kernel_memsize = kernel_size + (_end - _edata);
+
+ /*
+ * First, try a straight allocation at the preferred offset.
+ * This will work around the issue where, if dram_base == 0x0,
+ * efi_low_alloc() refuses to allocate at 0x0 (to prevent the
+ * address of the allocation to be mistaken for a FAIL return
+ * value or a NULL pointer). It will also ensure that, on
+ * platforms where the [dram_base, dram_base + TEXT_OFFSET)
+ * interval is partially occupied by the firmware (like on APM
+ * Mustang), we can still place the kernel at the address
+ * 'dram_base + TEXT_OFFSET'.
+ */
+ *image_addr = *reserve_addr = dram_base + TEXT_OFFSET;
+ nr_pages = round_up(kernel_memsize, EFI_ALLOC_ALIGN) /
+ EFI_PAGE_SIZE;
+ status = efi_call_early(allocate_pages, EFI_ALLOCATE_ADDRESS,
+ EFI_LOADER_DATA, nr_pages,
+ (efi_physical_addr_t *)reserve_addr);
+ if (status != EFI_SUCCESS) {
+ kernel_memsize += TEXT_OFFSET;
+ status = efi_low_alloc(sys_table_arg, kernel_memsize,
+ SZ_2M, reserve_addr);
+
+ if (status != EFI_SUCCESS) {
+ pr_efi_err(sys_table_arg, "Failed to relocate kernel\n");
+ return status;
+ }
+ *image_addr = *reserve_addr + TEXT_OFFSET;
+ }
+ memcpy((void *)*image_addr, old_image_addr, kernel_size);
+ *reserve_size = kernel_memsize;
+ }
+
+
+ return EFI_SUCCESS;
+}