x86: Add relocation and link script for a 64-bit EFI application

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>
This commit is contained in:
Simon Glass 2015-08-04 12:33:51 -06:00
parent cd326a32c9
commit 465a67cf52
2 changed files with 149 additions and 0 deletions

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/*
* 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) }
}

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/*
* 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;
}