980771f616
The practice of using __pure getter functions to access global variables in the EFI stub dates back to the time when we had to carefully prevent GOT entries from being emitted, because we could not rely on the toolchain to do this for us. Today, we use the hidden visibility pragma for all EFI stub source files, which now all live in the same subdirectory, and we apply a sanity check on the objects, so we can get rid of these getter functions and simply refer to global data objects directly. So switch over the remaining boolean variables carrying options set on the kernel command line. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
116 lines
3.2 KiB
C
116 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2013, 2014 Linaro Ltd; <roy.franz@linaro.org>
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*
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* This file implements the EFI boot stub for the arm64 kernel.
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* Adapted from ARM version by Mark Salter <msalter@redhat.com>
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*/
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#include <linux/efi.h>
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#include <asm/efi.h>
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#include <asm/memory.h>
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#include <asm/sections.h>
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#include <asm/sysreg.h>
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#include "efistub.h"
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efi_status_t check_platform_features(void)
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{
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u64 tg;
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/* UEFI mandates support for 4 KB granularity, no need to check */
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if (IS_ENABLED(CONFIG_ARM64_4K_PAGES))
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return EFI_SUCCESS;
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tg = (read_cpuid(ID_AA64MMFR0_EL1) >> ID_AA64MMFR0_TGRAN_SHIFT) & 0xf;
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if (tg != ID_AA64MMFR0_TGRAN_SUPPORTED) {
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if (IS_ENABLED(CONFIG_ARM64_64K_PAGES))
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pr_efi_err("This 64 KB granular kernel is not supported by your CPU\n");
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else
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pr_efi_err("This 16 KB granular kernel is not supported by your CPU\n");
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return EFI_UNSUPPORTED;
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}
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return EFI_SUCCESS;
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}
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/*
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* Relocatable kernels can fix up the misalignment with respect to
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* MIN_KIMG_ALIGN, so they only require a minimum alignment of EFI_KIMG_ALIGN
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* (which accounts for the alignment of statically allocated objects such as
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* the swapper stack.)
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*/
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static const u64 min_kimg_align = IS_ENABLED(CONFIG_RELOCATABLE) ? EFI_KIMG_ALIGN
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: MIN_KIMG_ALIGN;
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efi_status_t handle_kernel_image(unsigned long *image_addr,
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unsigned long *image_size,
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unsigned long *reserve_addr,
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unsigned long *reserve_size,
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unsigned long dram_base,
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efi_loaded_image_t *image)
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{
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efi_status_t status;
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unsigned long kernel_size, kernel_memsize = 0;
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u32 phys_seed = 0;
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if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
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if (!efi_nokaslr) {
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status = efi_get_random_bytes(sizeof(phys_seed),
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(u8 *)&phys_seed);
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if (status == EFI_NOT_FOUND) {
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pr_efi("EFI_RNG_PROTOCOL unavailable, no randomness supplied\n");
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} else if (status != EFI_SUCCESS) {
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pr_efi_err("efi_get_random_bytes() failed\n");
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return status;
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}
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} else {
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pr_efi("KASLR disabled on kernel command line\n");
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}
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}
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if (image->image_base != _text)
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pr_efi_err("FIRMWARE BUG: efi_loaded_image_t::image_base has bogus value\n");
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kernel_size = _edata - _text;
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kernel_memsize = kernel_size + (_end - _edata);
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*reserve_size = kernel_memsize + TEXT_OFFSET % min_kimg_align;
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if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) {
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/*
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* If KASLR is enabled, and we have some randomness available,
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* locate the kernel at a randomized offset in physical memory.
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*/
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status = efi_random_alloc(*reserve_size, min_kimg_align,
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reserve_addr, phys_seed);
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} else {
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status = EFI_OUT_OF_RESOURCES;
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}
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if (status != EFI_SUCCESS) {
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if (IS_ALIGNED((u64)_text - TEXT_OFFSET, min_kimg_align)) {
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/*
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* Just execute from wherever we were loaded by the
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* UEFI PE/COFF loader if the alignment is suitable.
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*/
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*image_addr = (u64)_text;
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*reserve_size = 0;
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return EFI_SUCCESS;
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}
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status = efi_allocate_pages_aligned(*reserve_size, reserve_addr,
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ULONG_MAX, min_kimg_align);
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if (status != EFI_SUCCESS) {
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pr_efi_err("Failed to relocate kernel\n");
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*reserve_size = 0;
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return status;
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}
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}
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*image_addr = *reserve_addr + TEXT_OFFSET % min_kimg_align;
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memcpy((void *)*image_addr, _text, kernel_size);
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return EFI_SUCCESS;
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}
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