diff options
Diffstat (limited to 'drivers/firmware/efi/libstub')
| -rw-r--r-- | drivers/firmware/efi/libstub/Makefile | 42 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/arm64-stub.c | 78 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/fdt.c | 9 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/string.c | 57 |
4 files changed, 171 insertions, 15 deletions
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 816dbe9f4b82..3c0467d3688c 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -14,6 +14,8 @@ cflags-$(CONFIG_ARM64) := $(subst -pg,,$(KBUILD_CFLAGS)) cflags-$(CONFIG_ARM) := $(subst -pg,,$(KBUILD_CFLAGS)) \ -fno-builtin -fpic -mno-single-pic-base +cflags-$(CONFIG_EFI_ARMSTUB) += -I$(srctree)/scripts/dtc/libfdt + KBUILD_CFLAGS := $(cflags-y) \ $(call cc-option,-ffreestanding) \ $(call cc-option,-fno-stack-protector) @@ -22,7 +24,18 @@ GCOV_PROFILE := n KASAN_SANITIZE := n lib-y := efi-stub-helper.o -lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o + +# include the stub's generic dependencies from lib/ when building for ARM/arm64 +arm-deps := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c sort.c + +$(obj)/lib-%.o: $(srctree)/lib/%.c FORCE + $(call if_changed_rule,cc_o_c) + +lib-$(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 @@ -30,10 +43,27 @@ lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o # So let's apply the __init annotations at the section level, by prefixing # the section names directly. This will ensure that even all the inline string # literals are covered. +# The fact that the stub and the kernel proper are essentially the same binary +# also means that we need to be extra careful to make sure that the stub does +# not rely on any absolute symbol references, considering that the virtual +# kernel mapping that the linker uses is not active yet when the stub is +# executing. So build all C dependencies of the EFI stub into libstub, and do +# a verification pass to see if any absolute relocations exist in any of the +# object files. # -extra-$(CONFIG_ARM64) := $(lib-y) -lib-$(CONFIG_ARM64) := $(patsubst %.o,%.init.o,$(lib-y)) +extra-$(CONFIG_EFI_ARMSTUB) := $(lib-y) +lib-$(CONFIG_EFI_ARMSTUB) := $(patsubst %.o,%.stub.o,$(lib-y)) + +STUBCOPY_FLAGS-y := -R .debug* -R *ksymtab* -R *kcrctab* +STUBCOPY_FLAGS-$(CONFIG_ARM64) += --prefix-alloc-sections=.init \ + --prefix-symbols=__efistub_ +STUBCOPY_RELOC-$(CONFIG_ARM64) := R_AARCH64_ABS + +$(obj)/%.stub.o: $(obj)/%.o FORCE + $(call if_changed,stubcopy) -OBJCOPYFLAGS := --prefix-alloc-sections=.init -$(obj)/%.init.o: $(obj)/%.o FORCE - $(call if_changed,objcopy) +quiet_cmd_stubcopy = STUBCPY $@ + cmd_stubcopy = if $(OBJCOPY) $(STUBCOPY_FLAGS-y) $< $@; then \ + $(OBJDUMP) -r $@ | grep $(STUBCOPY_RELOC-y) \ + && (echo >&2 "$@: absolute symbol references not allowed in the EFI stub"; \ + rm -f $@; /bin/false); else /bin/false; fi diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c new file mode 100644 index 000000000000..78dfbd34b6bf --- /dev/null +++ b/drivers/firmware/efi/libstub/arm64-stub.c @@ -0,0 +1,78 @@ +/* + * 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; + unsigned long preferred_offset; + + /* + * The preferred offset of the kernel Image is TEXT_OFFSET bytes beyond + * a 2 MB aligned base, which itself may be lower than dram_base, as + * long as the resulting offset equals or exceeds it. + */ + preferred_offset = round_down(dram_base, SZ_2M) + TEXT_OFFSET; + if (preferred_offset < dram_base) + preferred_offset += SZ_2M; + + /* Relocate the image, if required. */ + kernel_size = _edata - _text; + if (*image_addr != preferred_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 = preferred_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; +} diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c index ef5d764e2a27..b62e2f5dcab3 100644 --- a/drivers/firmware/efi/libstub/fdt.c +++ b/drivers/firmware/efi/libstub/fdt.c @@ -147,15 +147,6 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, if (status) goto fdt_set_fail; - /* - * Add kernel version banner so stub/kernel match can be - * verified. - */ - status = fdt_setprop_string(fdt, node, "linux,uefi-stub-kern-ver", - linux_banner); - if (status) - goto fdt_set_fail; - return EFI_SUCCESS; fdt_set_fail: diff --git a/drivers/firmware/efi/libstub/string.c b/drivers/firmware/efi/libstub/string.c new file mode 100644 index 000000000000..09d5a0894343 --- /dev/null +++ b/drivers/firmware/efi/libstub/string.c @@ -0,0 +1,57 @@ +/* + * Taken from: + * linux/lib/string.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + */ + +#include <linux/types.h> +#include <linux/string.h> + +#ifndef __HAVE_ARCH_STRSTR +/** + * strstr - Find the first substring in a %NUL terminated string + * @s1: The string to be searched + * @s2: The string to search for + */ +char *strstr(const char *s1, const char *s2) +{ + size_t l1, l2; + + l2 = strlen(s2); + if (!l2) + return (char *)s1; + l1 = strlen(s1); + while (l1 >= l2) { + l1--; + if (!memcmp(s1, s2, l2)) + return (char *)s1; + s1++; + } + return NULL; +} +#endif + +#ifndef __HAVE_ARCH_STRNCMP +/** + * strncmp - Compare two length-limited strings + * @cs: One string + * @ct: Another string + * @count: The maximum number of bytes to compare + */ +int strncmp(const char *cs, const char *ct, size_t count) +{ + unsigned char c1, c2; + + while (count) { + c1 = *cs++; + c2 = *ct++; + if (c1 != c2) + return c1 < c2 ? -1 : 1; + if (!c1) + break; + count--; + } + return 0; +} +#endif |