[U-Boot] [PATCH 33/48] x86: Add relocation and link script for a 64-bit EFI application
Bin Meng
bmeng.cn at gmail.com
Thu Jul 23 14:35:45 CEST 2015
Hi Simon,
On Wed, Jul 22, 2015 at 11:49 PM, Simon Glass <sjg at chromium.org> wrote:
> Add a link script and relocation code for building 64-bit EFI applications.
Nits: linker script
> This can be used for the EFI stub.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
>
> arch/x86/cpu/efi/elf_x86_64_efi.lds | 87 +++++++++++++++++++++++++++++++++++
> arch/x86/lib/reloc_x86_64.c | 90 +++++++++++++++++++++++++++++++++++++
> 2 files changed, 177 insertions(+)
> create mode 100644 arch/x86/cpu/efi/elf_x86_64_efi.lds
> create mode 100644 arch/x86/lib/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..369f146
> --- /dev/null
> +++ b/arch/x86/cpu/efi/elf_x86_64_efi.lds
> @@ -0,0 +1,87 @@
> +/*
> + * U-Boot EFI link script
> + *
Ditto.
> + * SPDX-License-Identifier: bsd-2-clause
> + *
> + * Modified from usr/lib32/elf_ia32_efi.lds in gnu-efi
I guess you want to say: usr/lib32/elf_x86_64_efi.lds
> + */
> +
> +#include <config.h>
> +
> +OUTPUT_FORMAT("elf64-x86-64", "elf64-x86-64", "elf64-x86-64")
> +OUTPUT_ARCH(i386:x86-64)
> +ENTRY(_start)
> +SECTIONS
> +{
> + . = 0x0;
We don't have this line in the elf_ia32_efi.lds. Can this be removed.
Or we need add the same in the 32-bit lds.
(BTW: I checked gnu-efi, it has this line)
> + ImageBase = .;
CamelCase
> + .hash : { *(.hash) } /* this MUST come first! */
> + . = 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);
> + KEEP(*(SORT(.u_boot_list*)));
> + . = ALIGN(8);
> + KEEP(*(.dtb*));
> + /* Keep U-Boot payload */
> + . = ALIGN(8);
> + KEEP(*(.u_boot_bin.*));
> + }
> +
> + . = 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/reloc_x86_64.c b/arch/x86/lib/reloc_x86_64.c
> new file mode 100644
> index 0000000..70a2b2a
> --- /dev/null
> +++ b/arch/x86/lib/reloc_x86_64.c
> @@ -0,0 +1,90 @@
> +/* reloc_x86_64.c - position independent x86_64 ELF shared object relocator
> + Copyright (C) 1999 Hewlett-Packard Co.
> + Contributed by David Mosberger <davidm at hpl.hp.com>.
> + Copyright (C) 2005 Intel Co.
> + Contributed by Fenghua Yu <fenghua.yu at intel.com>.
> +
> + All rights reserved.
> +
> + Redistribution and use in source and binary forms, with or without
> + modification, are permitted provided that the following conditions
> + are met:
> +
> + * Redistributions of source code must retain the above copyright
> + notice, this list of conditions and the following disclaimer.
> + * Redistributions in binary form must reproduce the above
> + copyright notice, this list of conditions and the following
> + disclaimer in the documentation and/or other materials
> + provided with the distribution.
> + * Neither the name of Hewlett-Packard Co. nor the names of its
> + contributors may be used to endorse or promote products derived
> + from this software without specific prior written permission.
> +
> + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
> + CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
> + INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
> + MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
> + DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
> + BE LIABLE FOR ANYDIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
> + OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
> + PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
> + PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
> + THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
> + TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
> + THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + SUCH DAMAGE.
Please replace this with SPDX version.
> +*/
> +
> +#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;
> + struct 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 = (struct 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 = (struct elf64_rel *)((char *)rel + relent);
> + relsz -= relent;
> + }
Nits: blank line
> + return EFI_SUCCESS;
> +}
> --
Regards,
Bin
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