Re: [U-Boot] [PATCH 33/48] x86: Add relocation and link script for a 64-bit EFI application

Hi Simon,

On Wed, Jul 22, 2015 at 11:49 PM, Simon Glass sjg@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@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@hpl.hp.com>.
  

• Copyright (C) 2005 Intel Co.

•   Contributed by Fenghua Yu <fenghua.yu@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