/* grub-mkimage.c - make a bootable image */ /* * GRUB -- GRand Unified Bootloader * Copyright (C) 2002,2003,2004,2005,2006,2007,2008,2009,2010 Free Software Foundation, Inc. * * GRUB is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * GRUB is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with GRUB. If not, see . */ #undef ELF_R_SYM #undef ELF_R_TYPE #if defined(MKIMAGE_ELF32) # define SUFFIX(x) x ## 32 # define ELFCLASSXX ELFCLASS32 # define Elf_Ehdr Elf32_Ehdr # define Elf_Phdr Elf32_Phdr # define Elf_Addr Elf32_Addr # define Elf_Sym Elf32_Sym # define Elf_Off Elf32_Off # define Elf_Shdr Elf32_Shdr # define Elf_Rela Elf32_Rela # define Elf_Rel Elf32_Rel # define Elf_Word Elf32_Word # define Elf_Half Elf32_Half # define Elf_Section Elf32_Section # define ELF_R_SYM(val) ELF32_R_SYM(val) # define ELF_R_TYPE(val) ELF32_R_TYPE(val) # define ELF_ST_TYPE(val) ELF32_ST_TYPE(val) #elif defined(MKIMAGE_ELF64) # define SUFFIX(x) x ## 64 # define ELFCLASSXX ELFCLASS64 # define Elf_Ehdr Elf64_Ehdr # define Elf_Phdr Elf64_Phdr # define Elf_Addr Elf64_Addr # define Elf_Sym Elf64_Sym # define Elf_Off Elf64_Off # define Elf_Shdr Elf64_Shdr # define Elf_Rela Elf64_Rela # define Elf_Rel Elf64_Rel # define Elf_Word Elf64_Word # define Elf_Half Elf64_Half # define Elf_Section Elf64_Section # define ELF_R_SYM(val) ELF64_R_SYM(val) # define ELF_R_TYPE(val) ELF64_R_TYPE(val) # define ELF_ST_TYPE(val) ELF64_ST_TYPE(val) #else #error "I'm confused" #endif static Elf_Addr SUFFIX (entry_point); /* Relocate symbols; note that this function overwrites the symbol table. Return the address of a start symbol. */ static Elf_Addr SUFFIX (relocate_symbols) (Elf_Ehdr *e, Elf_Shdr *sections, Elf_Shdr *symtab_section, Elf_Addr *section_addresses, Elf_Half section_entsize, Elf_Half num_sections, void *jumpers, Elf_Addr jumpers_addr, const struct grub_install_image_target_desc *image_target) { Elf_Word symtab_size, sym_size, num_syms; Elf_Off symtab_offset; Elf_Addr start_address = 0; Elf_Sym *sym; Elf_Word i; Elf_Shdr *strtab_section; const char *strtab; grub_uint64_t *jptr = jumpers; strtab_section = (Elf_Shdr *) ((char *) sections + (grub_target_to_host32 (symtab_section->sh_link) * section_entsize)); strtab = (char *) e + grub_target_to_host (strtab_section->sh_offset); symtab_size = grub_target_to_host (symtab_section->sh_size); sym_size = grub_target_to_host (symtab_section->sh_entsize); symtab_offset = grub_target_to_host (symtab_section->sh_offset); num_syms = symtab_size / sym_size; for (i = 0, sym = (Elf_Sym *) ((char *) e + symtab_offset); i < num_syms; i++, sym = (Elf_Sym *) ((char *) sym + sym_size)) { Elf_Section cur_index; const char *name; name = strtab + grub_target_to_host32 (sym->st_name); cur_index = grub_target_to_host16 (sym->st_shndx); if (cur_index == STN_ABS) { continue; } else if (cur_index == STN_UNDEF) { if (sym->st_name) grub_util_error ("undefined symbol %s", name); else continue; } else if (cur_index >= num_sections) grub_util_error ("section %d does not exist", cur_index); sym->st_value = (grub_target_to_host (sym->st_value) + section_addresses[cur_index]); if (image_target->elf_target == EM_IA_64 && ELF_ST_TYPE (sym->st_info) == STT_FUNC) { *jptr = grub_host_to_target64 (sym->st_value); sym->st_value = (char *) jptr - (char *) jumpers + jumpers_addr; jptr++; *jptr = 0; jptr++; } grub_util_info ("locating %s at 0x%llx (0x%llx)", name, (unsigned long long) sym->st_value, (unsigned long long) section_addresses[cur_index]); if (! start_address) if (strcmp (name, "_start") == 0 || strcmp (name, "start") == 0) start_address = sym->st_value; } return start_address; } /* Return the address of a symbol at the index I in the section S. */ static Elf_Addr SUFFIX (get_symbol_address) (Elf_Ehdr *e, Elf_Shdr *s, Elf_Word i, const struct grub_install_image_target_desc *image_target) { Elf_Sym *sym; sym = (Elf_Sym *) ((char *) e + grub_target_to_host (s->sh_offset) + i * grub_target_to_host (s->sh_entsize)); return sym->st_value; } /* Return the address of a modified value. */ static Elf_Addr * SUFFIX (get_target_address) (Elf_Ehdr *e, Elf_Shdr *s, Elf_Addr offset, const struct grub_install_image_target_desc *image_target) { return (Elf_Addr *) ((char *) e + grub_target_to_host (s->sh_offset) + offset); } #ifdef MKIMAGE_ELF64 static Elf_Addr SUFFIX (count_funcs) (Elf_Ehdr *e, Elf_Shdr *symtab_section, const struct grub_install_image_target_desc *image_target) { Elf_Word symtab_size, sym_size, num_syms; Elf_Off symtab_offset; Elf_Sym *sym; Elf_Word i; int ret = 0; symtab_size = grub_target_to_host (symtab_section->sh_size); sym_size = grub_target_to_host (symtab_section->sh_entsize); symtab_offset = grub_target_to_host (symtab_section->sh_offset); num_syms = symtab_size / sym_size; for (i = 0, sym = (Elf_Sym *) ((char *) e + symtab_offset); i < num_syms; i++, sym = (Elf_Sym *) ((char *) sym + sym_size)) if (ELF_ST_TYPE (sym->st_info) == STT_FUNC) ret++; return ret; } #endif /* Deal with relocation information. This function relocates addresses within the virtual address space starting from 0. So only relative addresses can be fully resolved. Absolute addresses must be relocated again by a PE32 relocator when loaded. */ static void SUFFIX (relocate_addresses) (Elf_Ehdr *e, Elf_Shdr *sections, Elf_Addr *section_addresses, Elf_Half section_entsize, Elf_Half num_sections, const char *strtab, char *pe_target, Elf_Addr tramp_off, Elf_Addr got_off, const struct grub_install_image_target_desc *image_target) { Elf_Half i; Elf_Shdr *s; #ifdef MKIMAGE_ELF64 struct grub_ia64_trampoline *tr = (void *) (pe_target + tramp_off); grub_uint64_t *gpptr = (void *) (pe_target + got_off); #define MASK19 ((1 << 19) - 1) #endif for (i = 0, s = sections; i < num_sections; i++, s = (Elf_Shdr *) ((char *) s + section_entsize)) if ((s->sh_type == grub_host_to_target32 (SHT_REL)) || (s->sh_type == grub_host_to_target32 (SHT_RELA))) { Elf_Rela *r; Elf_Word rtab_size, r_size, num_rs; Elf_Off rtab_offset; Elf_Shdr *symtab_section; Elf_Word target_section_index; Elf_Addr target_section_addr; Elf_Shdr *target_section; Elf_Word j; symtab_section = (Elf_Shdr *) ((char *) sections + (grub_target_to_host32 (s->sh_link) * section_entsize)); target_section_index = grub_target_to_host32 (s->sh_info); target_section_addr = section_addresses[target_section_index]; target_section = (Elf_Shdr *) ((char *) sections + (target_section_index * section_entsize)); grub_util_info ("dealing with the relocation section %s for %s", strtab + grub_target_to_host32 (s->sh_name), strtab + grub_target_to_host32 (target_section->sh_name)); rtab_size = grub_target_to_host (s->sh_size); r_size = grub_target_to_host (s->sh_entsize); rtab_offset = grub_target_to_host (s->sh_offset); num_rs = rtab_size / r_size; for (j = 0, r = (Elf_Rela *) ((char *) e + rtab_offset); j < num_rs; j++, r = (Elf_Rela *) ((char *) r + r_size)) { Elf_Addr info; Elf_Addr offset; Elf_Addr sym_addr; Elf_Addr *target; Elf_Addr addend; offset = grub_target_to_host (r->r_offset); target = SUFFIX (get_target_address) (e, target_section, offset, image_target); info = grub_target_to_host (r->r_info); sym_addr = SUFFIX (get_symbol_address) (e, symtab_section, ELF_R_SYM (info), image_target); addend = (s->sh_type == grub_target_to_host32 (SHT_RELA)) ? grub_target_to_host (r->r_addend) : 0; switch (image_target->elf_target) { case EM_386: switch (ELF_R_TYPE (info)) { case R_386_NONE: break; case R_386_32: /* This is absolute. */ *target = grub_host_to_target32 (grub_target_to_host32 (*target) + addend + sym_addr); grub_util_info ("relocating an R_386_32 entry to 0x%llx at the offset 0x%llx", (unsigned long long) *target, (unsigned long long) offset); break; case R_386_PC32: /* This is relative. */ *target = grub_host_to_target32 (grub_target_to_host32 (*target) + addend + sym_addr - target_section_addr - offset - image_target->vaddr_offset); grub_util_info ("relocating an R_386_PC32 entry to 0x%llx at the offset 0x%llx", (unsigned long long) *target, (unsigned long long) offset); break; default: grub_util_error (_("relocation 0x%llx is not implemented yet"), (unsigned long long) ELF_R_TYPE (info)); break; } break; #ifdef MKIMAGE_ELF64 case EM_X86_64: switch (ELF_R_TYPE (info)) { case R_X86_64_NONE: break; case R_X86_64_64: *target = grub_host_to_target64 (grub_target_to_host64 (*target) + addend + sym_addr); grub_util_info ("relocating an R_X86_64_64 entry to 0x%llx at the offset 0x%llx", (unsigned long long) *target, (unsigned long long) offset); break; case R_X86_64_PC32: { grub_uint32_t *t32 = (grub_uint32_t *) target; *t32 = grub_host_to_target64 (grub_target_to_host32 (*t32) + addend + sym_addr - target_section_addr - offset - image_target->vaddr_offset); grub_util_info ("relocating an R_X86_64_PC32 entry to 0x%x at the offset 0x%llx", *t32, (unsigned long long) offset); break; } case R_X86_64_32: case R_X86_64_32S: { grub_uint32_t *t32 = (grub_uint32_t *) target; *t32 = grub_host_to_target64 (grub_target_to_host32 (*t32) + addend + sym_addr); grub_util_info ("relocating an R_X86_64_32(S) entry to 0x%x at the offset 0x%llx", *t32, (unsigned long long) offset); break; } default: grub_util_error (_("relocation 0x%llx is not implemented yet"), (unsigned long long) ELF_R_TYPE (info)); break; } break; case EM_IA_64: switch (ELF_R_TYPE (info)) { case R_IA64_PCREL21B: { grub_uint64_t noff; grub_ia64_make_trampoline (tr, addend + sym_addr); noff = ((char *) tr - (char *) pe_target - target_section_addr - (offset & ~3)) >> 4; tr++; if (noff & ~MASK19) grub_util_error ("trampoline offset too big (%" PRIxGRUB_UINT64_T ")", noff); grub_ia64_add_value_to_slot_20b ((grub_addr_t) target, noff); } break; case R_IA64_LTOFF22X: case R_IA64_LTOFF22: { Elf_Sym *sym; sym = (Elf_Sym *) ((char *) e + grub_target_to_host (symtab_section->sh_offset) + ELF_R_SYM (info) * grub_target_to_host (symtab_section->sh_entsize)); if (ELF_ST_TYPE (sym->st_info) == STT_FUNC) sym_addr = grub_target_to_host64 (*(grub_uint64_t *) (pe_target + sym->st_value - image_target->vaddr_offset)); } case R_IA64_LTOFF_FPTR22: *gpptr = grub_host_to_target64 (addend + sym_addr); grub_ia64_add_value_to_slot_21 ((grub_addr_t) target, (char *) gpptr - (char *) pe_target + image_target->vaddr_offset); gpptr++; break; case R_IA64_GPREL22: grub_ia64_add_value_to_slot_21 ((grub_addr_t) target, addend + sym_addr); break; case R_IA64_PCREL64LSB: *target = grub_host_to_target64 (grub_target_to_host64 (*target) + addend + sym_addr - target_section_addr - offset - image_target->vaddr_offset); break; case R_IA64_SEGREL64LSB: *target = grub_host_to_target64 (grub_target_to_host64 (*target) + addend + sym_addr - target_section_addr); break; case R_IA64_DIR64LSB: case R_IA64_FPTR64LSB: *target = grub_host_to_target64 (grub_target_to_host64 (*target) + addend + sym_addr); grub_util_info ("relocating a direct entry to 0x%" PRIxGRUB_UINT64_T " at the offset 0x%llx", grub_target_to_host64 (*target), (unsigned long long) offset); break; /* We treat LTOFF22X as LTOFF22, so we can ignore LDXMOV. */ case R_IA64_LDXMOV: break; default: grub_util_error (_("relocation 0x%llx is not implemented yet"), (unsigned long long) ELF_R_TYPE (info)); break; } break; #endif #if defined(MKIMAGE_ELF32) case EM_ARM: { sym_addr += addend; sym_addr -= SUFFIX (entry_point); switch (ELF_R_TYPE (info)) { case R_ARM_ABS32: { grub_util_info (" ABS32:\toffset=%d\t(0x%08x)", (int) sym_addr, (int) sym_addr); /* Data will be naturally aligned */ sym_addr += 0x400; *target = grub_host_to_target32 (grub_target_to_host32 (*target) + sym_addr); } break; case R_ARM_THM_CALL: case R_ARM_THM_JUMP24: { grub_err_t err; grub_util_info (" THM_JUMP24:\ttarget=0x%08lx\toffset=(0x%08x)", (unsigned long) target, sym_addr); sym_addr -= offset; /* Thumb instructions can be 16-bit aligned */ err = grub_arm_reloc_thm_call ((grub_uint16_t *) target, sym_addr); if (err) grub_util_error ("%s", grub_errmsg); } break; case R_ARM_THM_JUMP19: { grub_err_t err; grub_util_info (" THM_JUMP19:\toffset=%d\t(0x%08x)", sym_addr, sym_addr); sym_addr -= offset; /* Thumb instructions can be 16-bit aligned */ err = grub_arm_reloc_thm_jump19 ((grub_uint16_t *) target, sym_addr); if (err) grub_util_error ("%s", grub_errmsg); } break; default: grub_util_error (_("relocation 0x%x is not implemented yet!"), ELF_R_TYPE (info)); break; } break; } #endif /* MKIMAGE_ELF32 */ default: grub_util_error ("unknown architecture type %d", image_target->elf_target); } } } } /* Add a PE32's fixup entry for a relocation. Return the resulting address after having written to the file OUT. */ static Elf_Addr SUFFIX (add_fixup_entry) (struct fixup_block_list **cblock, grub_uint16_t type, Elf_Addr addr, int flush, Elf_Addr current_address, const struct grub_install_image_target_desc *image_target) { struct grub_pe32_fixup_block *b; b = &((*cblock)->b); /* First, check if it is necessary to write out the current block. */ if ((*cblock)->state) { if (flush || addr < b->page_rva || b->page_rva + 0x1000 <= addr) { grub_uint32_t size; if (flush) { /* Add as much padding as necessary to align the address with a section boundary. */ Elf_Addr next_address; unsigned padding_size; size_t cur_index; next_address = current_address + b->block_size; padding_size = ((ALIGN_UP (next_address, image_target->section_align) - next_address) >> 1); cur_index = ((b->block_size - sizeof (*b)) >> 1); grub_util_info ("adding %d padding fixup entries", padding_size); while (padding_size--) { b->entries[cur_index++] = 0; b->block_size += 2; } } else while (b->block_size & (8 - 1)) { /* If not aligned with a 32-bit boundary, add a padding entry. */ size_t cur_index; grub_util_info ("adding a padding fixup entry"); cur_index = ((b->block_size - sizeof (*b)) >> 1); b->entries[cur_index] = 0; b->block_size += 2; } /* Flush it. */ grub_util_info ("writing %d bytes of a fixup block starting at 0x%x", b->block_size, b->page_rva); size = b->block_size; current_address += size; b->page_rva = grub_host_to_target32 (b->page_rva); b->block_size = grub_host_to_target32 (b->block_size); (*cblock)->next = xmalloc (sizeof (**cblock) + 2 * 0x1000); memset ((*cblock)->next, 0, sizeof (**cblock) + 2 * 0x1000); *cblock = (*cblock)->next; } } b = &((*cblock)->b); if (! flush) { grub_uint16_t entry; size_t cur_index; /* If not allocated yet, allocate a block with enough entries. */ if (! (*cblock)->state) { (*cblock)->state = 1; /* The spec does not mention the requirement of a Page RVA. Here, align the address with a 4K boundary for safety. */ b->page_rva = (addr & ~(0x1000 - 1)); b->block_size = sizeof (*b); } /* Sanity check. */ if (b->block_size >= sizeof (*b) + 2 * 0x1000) grub_util_error ("too many fixup entries"); /* Add a new entry. */ cur_index = ((b->block_size - sizeof (*b)) >> 1); entry = GRUB_PE32_FIXUP_ENTRY (type, addr - b->page_rva); b->entries[cur_index] = grub_host_to_target16 (entry); b->block_size += 2; } return current_address; } /* Make a .reloc section. */ static Elf_Addr SUFFIX (make_reloc_section) (Elf_Ehdr *e, void **out, Elf_Addr *section_addresses, Elf_Shdr *sections, Elf_Half section_entsize, Elf_Half num_sections, const char *strtab, Elf_Addr jumpers, grub_size_t njumpers, const struct grub_install_image_target_desc *image_target) { unsigned i; Elf_Shdr *s; struct fixup_block_list *lst, *lst0; Elf_Addr current_address = 0; lst = lst0 = xmalloc (sizeof (*lst) + 2 * 0x1000); memset (lst, 0, sizeof (*lst) + 2 * 0x1000); for (i = 0, s = sections; i < num_sections; i++, s = (Elf_Shdr *) ((char *) s + section_entsize)) if ((grub_target_to_host32 (s->sh_type) == SHT_REL) || (grub_target_to_host32 (s->sh_type) == SHT_RELA)) { Elf_Rel *r; Elf_Word rtab_size, r_size, num_rs; Elf_Off rtab_offset; Elf_Addr section_address; Elf_Word j; grub_util_info ("translating the relocation section %s", strtab + grub_le_to_cpu32 (s->sh_name)); rtab_size = grub_target_to_host (s->sh_size); r_size = grub_target_to_host (s->sh_entsize); rtab_offset = grub_target_to_host (s->sh_offset); num_rs = rtab_size / r_size; section_address = section_addresses[grub_le_to_cpu32 (s->sh_info)]; for (j = 0, r = (Elf_Rel *) ((char *) e + rtab_offset); j < num_rs; j++, r = (Elf_Rel *) ((char *) r + r_size)) { Elf_Addr info; Elf_Addr offset; offset = grub_target_to_host (r->r_offset); info = grub_target_to_host (r->r_info); /* Necessary to relocate only absolute addresses. */ switch (image_target->elf_target) { case EM_386: if (ELF_R_TYPE (info) == R_386_32) { Elf_Addr addr; addr = section_address + offset; grub_util_info ("adding a relocation entry for 0x%llx", (unsigned long long) addr); current_address = SUFFIX (add_fixup_entry) (&lst, GRUB_PE32_REL_BASED_HIGHLOW, addr, 0, current_address, image_target); } break; case EM_X86_64: if ((ELF_R_TYPE (info) == R_X86_64_32) || (ELF_R_TYPE (info) == R_X86_64_32S)) { grub_util_error ("can\'t add fixup entry for R_X86_64_32(S)"); } else if (ELF_R_TYPE (info) == R_X86_64_64) { Elf_Addr addr; addr = section_address + offset; grub_util_info ("adding a relocation entry for 0x%llx", (unsigned long long) addr); current_address = SUFFIX (add_fixup_entry) (&lst, GRUB_PE32_REL_BASED_DIR64, addr, 0, current_address, image_target); } break; case EM_IA_64: switch (ELF_R_TYPE (info)) { case R_IA64_PCREL64LSB: case R_IA64_LDXMOV: case R_IA64_PCREL21B: case R_IA64_LTOFF_FPTR22: case R_IA64_LTOFF22X: case R_IA64_LTOFF22: case R_IA64_GPREL22: case R_IA64_SEGREL64LSB: break; case R_IA64_FPTR64LSB: case R_IA64_DIR64LSB: #if 1 { Elf_Addr addr; addr = section_address + offset; grub_util_info ("adding a relocation entry for 0x%llx", (unsigned long long) addr); current_address = SUFFIX (add_fixup_entry) (&lst, GRUB_PE32_REL_BASED_DIR64, addr, 0, current_address, image_target); } #endif break; default: grub_util_error (_("relocation 0x%llx is not implemented yet"), (unsigned long long) ELF_R_TYPE (info)); break; } break; #if defined(MKIMAGE_ELF32) case EM_ARM: switch (ELF_R_TYPE (info)) { /* Relative relocations do not require fixup entries. */ case R_ARM_JUMP24: case R_ARM_THM_CALL: case R_ARM_THM_JUMP19: case R_ARM_THM_JUMP24: { Elf_Addr addr; addr = section_address + offset; grub_util_info (" %s: not adding fixup: 0x%08x : 0x%08x", __FUNCTION__, (unsigned int) addr, (unsigned int) current_address); } break; /* Create fixup entry for PE/COFF loader */ case R_ARM_ABS32: { Elf_Addr addr; addr = section_address + offset; current_address = SUFFIX (add_fixup_entry) (&lst, GRUB_PE32_REL_BASED_HIGHLOW, addr, 0, current_address, image_target); } break; default: grub_util_error (_("fixup for relocation 0x%x not implemented"), ELF_R_TYPE (info)); break; } break; #endif /* defined(MKIMAGE_ELF32) */ default: grub_util_error ("unknown machine type 0x%x", image_target->elf_target); } } } if (image_target->elf_target == EM_IA_64) for (i = 0; i < njumpers; i++) current_address = SUFFIX (add_fixup_entry) (&lst, GRUB_PE32_REL_BASED_DIR64, jumpers + 8 * i, 0, current_address, image_target); current_address = SUFFIX (add_fixup_entry) (&lst, 0, 0, 1, current_address, image_target); { grub_uint8_t *ptr; ptr = *out = xmalloc (current_address); for (lst = lst0; lst; lst = lst->next) if (lst->state) { memcpy (ptr, &lst->b, grub_target_to_host32 (lst->b.block_size)); ptr += grub_target_to_host32 (lst->b.block_size); } assert ((current_address + (grub_uint8_t *) *out) == ptr); } for (lst = lst0; lst; ) { struct fixup_block_list *next; next = lst->next; free (lst); lst = next; } return current_address; } /* Determine if this section is a text section. Return false if this section is not allocated. */ static int SUFFIX (is_text_section) (Elf_Shdr *s, const struct grub_install_image_target_desc *image_target) { if (image_target->id != IMAGE_EFI && grub_target_to_host32 (s->sh_type) != SHT_PROGBITS) return 0; return ((grub_target_to_host (s->sh_flags) & (SHF_EXECINSTR | SHF_ALLOC)) == (SHF_EXECINSTR | SHF_ALLOC)); } /* Determine if this section is a data section. This assumes that BSS is also a data section, since the converter initializes BSS when producing PE32 to avoid a bug in EFI implementations. */ static int SUFFIX (is_data_section) (Elf_Shdr *s, const struct grub_install_image_target_desc *image_target) { if (image_target->id != IMAGE_EFI && grub_target_to_host32 (s->sh_type) != SHT_PROGBITS) return 0; return ((grub_target_to_host (s->sh_flags) & (SHF_EXECINSTR | SHF_ALLOC)) == SHF_ALLOC); } /* Return if the ELF header is valid. */ static int SUFFIX (check_elf_header) (Elf_Ehdr *e, size_t size, const struct grub_install_image_target_desc *image_target) { if (size < sizeof (*e) || e->e_ident[EI_MAG0] != ELFMAG0 || e->e_ident[EI_MAG1] != ELFMAG1 || e->e_ident[EI_MAG2] != ELFMAG2 || e->e_ident[EI_MAG3] != ELFMAG3 || e->e_ident[EI_VERSION] != EV_CURRENT || e->e_ident[EI_CLASS] != ELFCLASSXX || e->e_version != grub_host_to_target32 (EV_CURRENT)) return 0; return 1; } /* Locate section addresses by merging code sections and data sections into .text and .data, respectively. Return the array of section addresses. */ static Elf_Addr * SUFFIX (locate_sections) (const char *kernel_path, Elf_Shdr *sections, Elf_Half section_entsize, Elf_Half num_sections, const char *strtab, size_t *exec_size, size_t *kernel_sz, size_t *all_align, const struct grub_install_image_target_desc *image_target) { int i; Elf_Addr current_address; Elf_Addr *section_addresses; Elf_Shdr *s; *all_align = 1; section_addresses = xmalloc (sizeof (*section_addresses) * num_sections); memset (section_addresses, 0, sizeof (*section_addresses) * num_sections); current_address = 0; for (i = 0, s = sections; i < num_sections; i++, s = (Elf_Shdr *) ((char *) s + section_entsize)) if ((grub_target_to_host (s->sh_flags) & SHF_ALLOC) && grub_host_to_target32 (s->sh_addralign) > *all_align) *all_align = grub_host_to_target32 (s->sh_addralign); /* .text */ for (i = 0, s = sections; i < num_sections; i++, s = (Elf_Shdr *) ((char *) s + section_entsize)) if (SUFFIX (is_text_section) (s, image_target)) { Elf_Word align = grub_host_to_target_addr (s->sh_addralign); const char *name = strtab + grub_host_to_target32 (s->sh_name); if (align) current_address = ALIGN_UP (current_address + image_target->vaddr_offset, align) - image_target->vaddr_offset; grub_util_info ("locating the section %s at 0x%llx", name, (unsigned long long) current_address); if (image_target->id != IMAGE_EFI) { current_address = grub_host_to_target_addr (s->sh_addr) - image_target->link_addr; if (grub_host_to_target_addr (s->sh_addr) != image_target->link_addr) grub_util_error ("`%s' is miscompiled: it's start address is 0x%llx" " instead of 0x%llx: ld.gold bug?", kernel_path, (unsigned long long) grub_host_to_target_addr (s->sh_addr), (unsigned long long) image_target->link_addr); } section_addresses[i] = current_address; current_address += grub_host_to_target_addr (s->sh_size); } current_address = ALIGN_UP (current_address + image_target->vaddr_offset, image_target->section_align) - image_target->vaddr_offset; *exec_size = current_address; /* .data */ for (i = 0, s = sections; i < num_sections; i++, s = (Elf_Shdr *) ((char *) s + section_entsize)) if (SUFFIX (is_data_section) (s, image_target)) { Elf_Word align = grub_host_to_target_addr (s->sh_addralign); const char *name = strtab + grub_host_to_target32 (s->sh_name); if (align) current_address = ALIGN_UP (current_address + image_target->vaddr_offset, align) - image_target->vaddr_offset; grub_util_info ("locating the section %s at 0x%llx", name, (unsigned long long) current_address); if (image_target->id != IMAGE_EFI) current_address = grub_host_to_target_addr (s->sh_addr) - image_target->link_addr; section_addresses[i] = current_address; current_address += grub_host_to_target_addr (s->sh_size); } current_address = ALIGN_UP (current_address + image_target->vaddr_offset, image_target->section_align) - image_target->vaddr_offset; *kernel_sz = current_address; return section_addresses; } static char * SUFFIX (load_image) (const char *kernel_path, size_t *exec_size, size_t *kernel_sz, size_t *bss_size, size_t total_module_size, grub_uint64_t *start, void **reloc_section, size_t *reloc_size, size_t *align, const struct grub_install_image_target_desc *image_target) { char *kernel_img, *out_img; const char *strtab; Elf_Ehdr *e; Elf_Shdr *sections; Elf_Addr *section_addresses; Elf_Addr *section_vaddresses; int i; Elf_Shdr *s; Elf_Half num_sections; Elf_Off section_offset; Elf_Half section_entsize; grub_size_t kernel_size; grub_size_t ia64jmp_off = 0, ia64_toff = 0, ia64_got_off = 0; unsigned ia64jmpnum = 0; Elf_Shdr *symtab_section = 0; grub_size_t got = 0; *start = 0; kernel_size = grub_util_get_image_size (kernel_path); kernel_img = xmalloc (kernel_size); grub_util_load_image (kernel_path, kernel_img); e = (Elf_Ehdr *) kernel_img; if (! SUFFIX (check_elf_header) (e, kernel_size, image_target)) grub_util_error ("invalid ELF header"); section_offset = grub_target_to_host (e->e_shoff); section_entsize = grub_target_to_host16 (e->e_shentsize); num_sections = grub_target_to_host16 (e->e_shnum); if (kernel_size < section_offset + section_entsize * num_sections) grub_util_error (_("premature end of file %s"), kernel_path); sections = (Elf_Shdr *) (kernel_img + section_offset); /* Relocate sections then symbols in the virtual address space. */ s = (Elf_Shdr *) ((char *) sections + grub_host_to_target16 (e->e_shstrndx) * section_entsize); strtab = (char *) e + grub_host_to_target_addr (s->sh_offset); section_addresses = SUFFIX (locate_sections) (kernel_path, sections, section_entsize, num_sections, strtab, exec_size, kernel_sz, align, image_target); section_vaddresses = xmalloc (sizeof (*section_addresses) * num_sections); for (i = 0; i < num_sections; i++) section_vaddresses[i] = section_addresses[i] + image_target->vaddr_offset; if (image_target->id != IMAGE_EFI) { Elf_Addr current_address = *kernel_sz; for (i = 0, s = sections; i < num_sections; i++, s = (Elf_Shdr *) ((char *) s + section_entsize)) if (grub_target_to_host32 (s->sh_type) == SHT_NOBITS) { Elf_Word sec_align = grub_host_to_target_addr (s->sh_addralign); const char *name = strtab + grub_host_to_target32 (s->sh_name); if (sec_align) current_address = ALIGN_UP (current_address + image_target->vaddr_offset, sec_align) - image_target->vaddr_offset; grub_util_info ("locating the section %s at 0x%llx", name, (unsigned long long) current_address); if (image_target->id != IMAGE_EFI) current_address = grub_host_to_target_addr (s->sh_addr) - image_target->link_addr; section_vaddresses[i] = current_address + image_target->vaddr_offset; current_address += grub_host_to_target_addr (s->sh_size); } current_address = ALIGN_UP (current_address + image_target->vaddr_offset, image_target->section_align) - image_target->vaddr_offset; *bss_size = current_address - *kernel_sz; } else *bss_size = 0; if (image_target->id == IMAGE_EFI) { symtab_section = NULL; for (i = 0, s = sections; i < num_sections; i++, s = (Elf_Shdr *) ((char *) s + section_entsize)) if (s->sh_type == grub_host_to_target32 (SHT_SYMTAB)) { symtab_section = s; break; } #ifdef MKIMAGE_ELF64 if (image_target->elf_target == EM_IA_64) { grub_size_t tramp; *kernel_sz = ALIGN_UP (*kernel_sz, 16); grub_ia64_dl_get_tramp_got_size (e, &tramp, &got); tramp *= sizeof (struct grub_ia64_trampoline); ia64_toff = *kernel_sz; *kernel_sz += ALIGN_UP (tramp, 16); ia64jmp_off = *kernel_sz; ia64jmpnum = SUFFIX (count_funcs) (e, symtab_section, image_target); *kernel_sz += 16 * ia64jmpnum; ia64_got_off = *kernel_sz; *kernel_sz += ALIGN_UP (got * sizeof (grub_uint64_t), 16); } #endif if (! symtab_section) grub_util_error ("%s", _("no symbol table")); } else { *reloc_size = 0; *reloc_section = NULL; } out_img = xmalloc (*kernel_sz + total_module_size); if (image_target->id == IMAGE_EFI) { *start = SUFFIX (relocate_symbols) (e, sections, symtab_section, section_vaddresses, section_entsize, num_sections, (char *) out_img + ia64jmp_off, ia64jmp_off + image_target->vaddr_offset, image_target); if (*start == 0) grub_util_error ("start symbol is not defined"); SUFFIX (entry_point) = (Elf_Addr) *start; /* Resolve addresses in the virtual address space. */ SUFFIX (relocate_addresses) (e, sections, section_addresses, section_entsize, num_sections, strtab, out_img, ia64_toff, ia64_got_off, image_target); *reloc_size = SUFFIX (make_reloc_section) (e, reloc_section, section_vaddresses, sections, section_entsize, num_sections, strtab, ia64jmp_off + image_target->vaddr_offset, 2 * ia64jmpnum + got, image_target); } for (i = 0, s = sections; i < num_sections; i++, s = (Elf_Shdr *) ((char *) s + section_entsize)) if (SUFFIX (is_data_section) (s, image_target) || SUFFIX (is_text_section) (s, image_target)) { if (grub_target_to_host32 (s->sh_type) == SHT_NOBITS) memset (out_img + section_addresses[i], 0, grub_host_to_target_addr (s->sh_size)); else memcpy (out_img + section_addresses[i], kernel_img + grub_host_to_target_addr (s->sh_offset), grub_host_to_target_addr (s->sh_size)); } free (kernel_img); free (section_vaddresses); free (section_addresses); return out_img; } #undef SUFFIX #undef ELFCLASSXX #undef Elf_Ehdr #undef Elf_Phdr #undef Elf_Shdr #undef Elf_Addr #undef Elf_Sym #undef Elf_Off #undef Elf_Rela #undef Elf_Rel #undef ELF_R_TYPE #undef ELF_R_SYM #undef Elf_Word #undef Elf_Half #undef Elf_Section #undef ELF_ST_TYPE