diff options
author | Ben Stoltz <stoltz@google.com> | 2015-08-04 18:33:46 (GMT) |
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committer | Simon Glass <sjg@chromium.org> | 2015-08-05 14:44:06 (GMT) |
commit | 3dcdd17b43c5cfd3a216169948dfd08d6741c631 (patch) | |
tree | 662ddb941487ea3be651530fc6ad9f74e8f6632d /arch/x86/lib | |
parent | ed3b4d37368694e682c2c24f2fd72414d3f645ae (diff) | |
download | u-boot-3dcdd17b43c5cfd3a216169948dfd08d6741c631.tar.xz |
x86: Add support for U-Boot as an EFI application
Add the required x86 glue code. This includes the initial start-up,
relocation and jumping to efi_main(). We also need to avoid fiddling with
interrupts.
Signed-off-by: Ben Stoltz <stoltz@google.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Diffstat (limited to 'arch/x86/lib')
-rw-r--r-- | arch/x86/lib/efi/crt0-efi-ia32.S | 52 | ||||
-rw-r--r-- | arch/x86/lib/efi/reloc_ia32.c | 72 |
2 files changed, 124 insertions, 0 deletions
diff --git a/arch/x86/lib/efi/crt0-efi-ia32.S b/arch/x86/lib/efi/crt0-efi-ia32.S new file mode 100644 index 0000000..30e5eb0 --- /dev/null +++ b/arch/x86/lib/efi/crt0-efi-ia32.S @@ -0,0 +1,52 @@ +/* + * crt0-efi-ia32.S - x86 EFI startup code. + * + * Copyright (C) 1999 Hewlett-Packard Co. + * Contributed by David Mosberger <davidm@hpl.hp.com>. + * All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + + .text + .align 4 + + .globl _start +_start: + pushl %ebp + movl %esp,%ebp + + pushl 12(%ebp) # copy "image" argument + pushl 8(%ebp) # copy "systab" argument + + call 0f +0: popl %eax + movl %eax,%ebx + + addl $image_base-0b,%eax # %eax = ldbase + addl $_DYNAMIC-0b,%ebx # %ebx = _DYNAMIC + + pushl %ebx # pass _DYNAMIC as second argument + pushl %eax # pass ldbase as first argument + call _relocate + popl %ebx + popl %ebx + testl %eax,%eax + jne .exit + call efi_main # call app with "image" and "systab" argument + +.exit: leave + ret + + /* + * hand-craft a dummy .reloc section so EFI knows it's a relocatable + * executable: + */ + .data +dummy: .long 0 + +#define IMAGE_REL_ABSOLUTE 0 + .section .reloc + .long dummy /* Page RVA */ + .long 10 /* Block Size (2*4+2) */ + .word (IMAGE_REL_ABSOLUTE << 12) + 0 /* reloc for dummy */ diff --git a/arch/x86/lib/efi/reloc_ia32.c b/arch/x86/lib/efi/reloc_ia32.c new file mode 100644 index 0000000..4d68255 --- /dev/null +++ b/arch/x86/lib/efi/reloc_ia32.c @@ -0,0 +1,72 @@ +/* + * reloc_ia32.c - position independent x86 ELF shared object relocator + * Copyright (C) 1999 Hewlett-Packard Co. + * Contributed by David Mosberger <davidm@hpl.hp.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, Elf32_Dyn *dyn, efi_handle_t image, + struct efi_system_table *systab) +{ + long relsz = 0, relent = 0; + Elf32_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_REL: + rel = (Elf32_Rel *)((unsigned long)dyn[i].d_un.d_ptr + + ldbase); + break; + + case DT_RELSZ: + relsz = dyn[i].d_un.d_val; + break; + + case DT_RELENT: + relent = dyn[i].d_un.d_val; + break; + + case DT_RELA: + 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 (ELF32_R_TYPE(rel->r_info)) { + case R_386_NONE: + break; + + case R_386_RELATIVE: + addr = (unsigned long *)(ldbase + rel->r_offset); + *addr += ldbase; + break; + + default: + break; + } + rel = (Elf32_Rel *)((char *)rel + relent); + relsz -= relent; + } + + return EFI_SUCCESS; +} |