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>

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 (file)
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 (file)
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;
+}