x86: Add support for 64-bit relocation

Add a 64-bit relocation function. SPL loads U-Boot into RAM at a fixed
address and runs it. U-Boot then relocates itself to the top of RAM using
this relocation function.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

diff --git a/arch/x86/lib/relocate.c b/arch/x86/lib/relocate.c
index 861e667..d207fdd 100644 (file)
--- a/arch/x86/lib/relocate.c
+++ b/arch/x86/lib/relocate.c
@@ -47,6 +47,46 @@ int clear_bss(void)
        return 0;
 }
 
+#if CONFIG_IS_ENABLED(X86_64)
+static void do_elf_reloc_fixups64(unsigned int text_base, uintptr_t size,
+                                 Elf64_Rela *re_src, Elf64_Rela *re_end)
+{
+       Elf64_Addr *offset_ptr_rom, *last_offset = NULL;
+       Elf64_Addr *offset_ptr_ram;
+
+       do {
+               /* Get the location from the relocation entry */
+               offset_ptr_rom = (Elf64_Addr *)(uintptr_t)re_src->r_offset;
+
+               /* Check that the location of the relocation is in .text */
+               if (offset_ptr_rom >= (Elf64_Addr *)(uintptr_t)text_base &&
+                   offset_ptr_rom > last_offset) {
+                       /* Switch to the in-RAM version */
+                       offset_ptr_ram = (Elf64_Addr *)((ulong)offset_ptr_rom +
+                                                       gd->reloc_off);
+
+                       /* Check that the target points into .text */
+                       if (*offset_ptr_ram >= text_base &&
+                           *offset_ptr_ram <= text_base + size) {
+                               *offset_ptr_ram = gd->reloc_off +
+                                                       re_src->r_addend;
+                       } else {
+                               debug("   %p: %lx: rom reloc %lx, ram %p, value %lx, limit %"
+                                     PRIXPTR "\n",
+                                     re_src, (ulong)re_src->r_info,
+                                     (ulong)re_src->r_offset, offset_ptr_ram,
+                                     (ulong)*offset_ptr_ram, text_base + size);
+                       }
+               } else {
+                       debug("   %p: %lx: rom reloc %lx, last %p\n", re_src,
+                             (ulong)re_src->r_info, (ulong)re_src->r_offset,
+                             last_offset);
+               }
+               last_offset = offset_ptr_rom;
+
+       } while (++re_src < re_end);
+}
+#else
 static void do_elf_reloc_fixups32(unsigned int text_base, uintptr_t size,
                                  Elf32_Rel *re_src, Elf32_Rel *re_end)
 {
@@ -84,6 +124,7 @@ static void do_elf_reloc_fixups32(unsigned int text_base, uintptr_t size,
 
        } while (++re_src < re_end);
 }
+#endif
 
 /*
  * This function has more error checking than you might expect. Please see
@@ -109,7 +150,11 @@ int do_elf_reloc_fixups(void)
 #else
        panic("No CONFIG_SYS_TEXT_BASE");
 #endif
+#if CONFIG_IS_ENABLED(X86_64)
+       do_elf_reloc_fixups64(text_base, size, re_src, re_end);
+#else
        do_elf_reloc_fixups32(text_base, size, re_src, re_end);
+#endif
 
        return 0;
 }