Add a linker script and relocation code for building 64-bit EFI applications. This can be used for the EFI stub.
Signed-off-by: Simon Glass sjg@chromium.org Improvements to how the payload is built: Signed-off-by: Bin Meng bmeng.cn@gmail.com Reviewed-by: Bin Meng bmeng.cn@gmail.com ---
Changes in v3: - Use "BSD-2-Clause" for the SPDX license
Changes in v2: - Add a comment as to why .hash has to be first in the linker script - Change 'link script' to 'linker script' - Drop . = 0x0; - Fix reference to elf_ia32_efi instead of elf_x86_64_efi - Merge in Bin's implementation of adding a U-Boot payload with objcopy - Remove KEEP in the EFI linker script since garbage collection is not enabled - Rename ImageBase to image_base - Update based on the elf.h changes
arch/x86/cpu/efi/elf_x86_64_efi.lds | 83 +++++++++++++++++++++++++++++++++++++ arch/x86/lib/efi/reloc_x86_64.c | 66 +++++++++++++++++++++++++++++ 2 files changed, 149 insertions(+) create mode 100644 arch/x86/cpu/efi/elf_x86_64_efi.lds create mode 100644 arch/x86/lib/efi/reloc_x86_64.c
diff --git a/arch/x86/cpu/efi/elf_x86_64_efi.lds b/arch/x86/cpu/efi/elf_x86_64_efi.lds new file mode 100644 index 0000000..9d9f057 --- /dev/null +++ b/arch/x86/cpu/efi/elf_x86_64_efi.lds @@ -0,0 +1,83 @@ +/* + * U-Boot EFI linker script + * + * SPDX-License-Identifier: BSD-2-Clause + * + * Modified from usr/lib32/elf_x86_64_efi.lds in gnu-efi + */ + +#include <config.h> + +OUTPUT_FORMAT("elf64-x86-64", "elf64-x86-64", "elf64-x86-64") +OUTPUT_ARCH(i386:x86-64) +ENTRY(_start) +SECTIONS +{ + image_base = .; + .hash : { *(.hash) } /* this MUST come first, EFI expects it */ + . = ALIGN(4096); + .eh_frame : { + *(.eh_frame) + } + + . = ALIGN(4096); + + .text : { + *(.text) + *(.text.*) + *(.gnu.linkonce.t.*) + } + + . = ALIGN(4096); + + .reloc : { + *(.reloc) + } + + . = ALIGN(4096); + + .data : { + *(.rodata*) + *(.got.plt) + *(.got) + *(.data*) + *(.sdata) + /* the EFI loader doesn't seem to like a .bss section, so we stick + * it all into .data: */ + *(.sbss) + *(.scommon) + *(.dynbss) + *(.bss) + *(COMMON) + *(.rel.local) + + /* U-Boot lists and device tree */ + . = ALIGN(8); + *(SORT(.u_boot_list*)); + . = ALIGN(8); + *(.dtb*); + } + + . = ALIGN(4096); + .dynamic : { *(.dynamic) } + . = ALIGN(4096); + + .rela : { + *(.rela.data*) + *(.rela.got) + *(.rela.stab) + } + + . = ALIGN(4096); + .dynsym : { *(.dynsym) } + . = ALIGN(4096); + .dynstr : { *(.dynstr) } + . = ALIGN(4096); + .ignored.reloc : { + *(.rela.reloc) + *(.eh_frame) + *(.note.GNU-stack) + } + + .comment 0 : { *(.comment) } +} diff --git a/arch/x86/lib/efi/reloc_x86_64.c b/arch/x86/lib/efi/reloc_x86_64.c new file mode 100644 index 0000000..5f71f2a --- /dev/null +++ b/arch/x86/lib/efi/reloc_x86_64.c @@ -0,0 +1,66 @@ +/* + * reloc_x86_64.c - position independent x86_64 ELF shared object relocator + * Copyright (C) 1999 Hewlett-Packard Co. + * Contributed by David Mosberger davidm@hpl.hp.com. + * Copyright (C) 2005 Intel Co. + * Contributed by Fenghua Yu fenghua.yu@intel.com. + * + * All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <common.h> +#include <efi.h> +#include <elf.h> +#include <asm/elf.h> + +efi_status_t _relocate(long ldbase, Elf64_Dyn *dyn, efi_handle_t image, + struct efi_system_table *systab) +{ + long relsz = 0, relent = 0; + Elf64_Rel *rel = 0; + unsigned long *addr; + int i; + + for (i = 0; dyn[i].d_tag != DT_NULL; ++i) { + switch (dyn[i].d_tag) { + case DT_RELA: + rel = (Elf64_Rel *) + ((unsigned long)dyn[i].d_un.d_ptr + ldbase); + break; + case DT_RELASZ: + relsz = dyn[i].d_un.d_val; + break; + case DT_RELAENT: + relent = dyn[i].d_un.d_val; + break; + default: + break; + } + } + + if (!rel && relent == 0) + return EFI_SUCCESS; + + if (!rel || relent == 0) + return EFI_LOAD_ERROR; + + while (relsz > 0) { + /* apply the relocs */ + switch (ELF64_R_TYPE(rel->r_info)) { + case R_X86_64_NONE: + break; + case R_X86_64_RELATIVE: + addr = (unsigned long *)(ldbase + rel->r_offset); + *addr += ldbase; + break; + default: + break; + } + rel = (Elf64_Rel *)((char *)rel + relent); + relsz -= relent; + } + + return EFI_SUCCESS; +}