diff options
Diffstat (limited to 'util/grub-pe2elf.c')
| -rw-r--r-- | util/grub-pe2elf.c | 537 |
1 files changed, 537 insertions, 0 deletions
diff --git a/util/grub-pe2elf.c b/util/grub-pe2elf.c new file mode 100644 index 0000000..4b93faa --- /dev/null +++ b/util/grub-pe2elf.c @@ -0,0 +1,537 @@ +/* grub-pe2elf.c - tool to convert pe image to elf. */ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2008,2009 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 <http://www.gnu.org/licenses/>. + */ + +#include <config.h> +#include <grub/types.h> +#include <grub/util/misc.h> +#include <grub/elf.h> +#include <grub/efi/pe32.h> + +#include <stdio.h> +#include <unistd.h> +#include <string.h> +#include <stdlib.h> +#include <getopt.h> + +#include "progname.h" + +static struct option options[] = { + {"help", no_argument, 0, 'h'}, + {"version", no_argument, 0, 'V'}, + {"verbose", no_argument, 0, 'v'}, + {0, 0, 0, 0} +}; + +static void +usage (int status) +{ + if (status) + fprintf (stderr, "Try `%s --help' for more information.\n", program_name); + else + printf ("\ +Usage: %s [OPTIONS] input [output]\n\ +\n\ +Tool to convert pe image to elf.\n\ +\nOptions:\n\ + -h, --help display this message and exit\n\ + -V, --version print version information and exit\n\ + -v, --verbose print verbose messages\n\ +\n\ +Report bugs to <%s>.\n", program_name, PACKAGE_BUGREPORT); + + exit (status); +} + +/* + * Section layout + * + * null + * .text + * .rdata + * .data + * .bss + * .modname + * .moddeps + * .symtab + * .strtab + * relocation sections + */ + +#define TEXT_SECTION 1 +#define RDATA_SECTION 2 +#define DATA_SECTION 3 +#define BSS_SECTION 4 +#define MODNAME_SECTION 5 +#define MODDEPS_SECTION 6 +#define MODLICENSE_SECTION 7 +#define SYMTAB_SECTION 8 +#define STRTAB_SECTION 9 + +#define REL_SECTION 10 +#define MAX_SECTIONS 16 + +#define STRTAB_BLOCK 256 + +static char *strtab; +static int strtab_max, strtab_len; + +Elf32_Ehdr ehdr; +Elf32_Shdr shdr[MAX_SECTIONS]; +int num_sections; +grub_uint32_t offset; + +static int +insert_string (const char *name) +{ + int len, result; + + if (*name == '_') + name++; + + len = strlen (name); + if (strtab_len + len >= strtab_max) + { + strtab_max += STRTAB_BLOCK; + strtab = xrealloc (strtab, strtab_max); + } + + strcpy (strtab + strtab_len, name); + result = strtab_len; + strtab_len += len + 1; + + return result; +} + +static int * +write_section_data (FILE* fp, char *image, + struct grub_pe32_coff_header *pe_chdr, + struct grub_pe32_section_table *pe_shdr) +{ + int *section_map; + int i; + char *pe_strtab = (image + pe_chdr->symtab_offset + + pe_chdr->num_symbols * sizeof (struct grub_pe32_symbol)); + + section_map = xmalloc ((pe_chdr->num_sections + 1) * sizeof (int)); + section_map[0] = 0; + + for (i = 0; i < pe_chdr->num_sections; i++, pe_shdr++) + { + grub_uint32_t idx; + const char *name = pe_shdr->name; + + if (name[0] == '/' && isdigit (name[1])) + { + char t[sizeof (pe_shdr->name) + 1]; + memcpy (t, name, sizeof (pe_shdr->name)); + t[sizeof (pe_shdr->name)] = 0; + name = pe_strtab + atoi (t + 1); + } + + if (! strcmp (name, ".text")) + { + idx = TEXT_SECTION; + shdr[idx].sh_flags = SHF_ALLOC | SHF_EXECINSTR; + } + else if (! strcmp (name, ".rdata")) + { + idx = RDATA_SECTION; + shdr[idx].sh_flags = SHF_ALLOC; + } + else if (! strcmp (name, ".data")) + { + idx = DATA_SECTION; + shdr[idx].sh_flags = SHF_ALLOC | SHF_WRITE; + } + else if (! strcmp (name, ".bss")) + { + idx = BSS_SECTION; + shdr[idx].sh_flags = SHF_ALLOC | SHF_WRITE; + } + else if (! strcmp (name, ".modname")) + idx = MODNAME_SECTION; + else if (! strcmp (name, ".moddeps")) + idx = MODDEPS_SECTION; + else if (strcmp (name, ".module_license") == 0) + idx = MODLICENSE_SECTION; + else + { + section_map[i + 1] = -1; + continue; + } + + section_map[i + 1] = idx; + + shdr[idx].sh_type = (idx == BSS_SECTION) ? SHT_NOBITS : SHT_PROGBITS; + shdr[idx].sh_size = pe_shdr->raw_data_size; + shdr[idx].sh_addralign = 1 << (((pe_shdr->characteristics >> + GRUB_PE32_SCN_ALIGN_SHIFT) & + GRUB_PE32_SCN_ALIGN_MASK) - 1); + + if (idx != BSS_SECTION) + { + shdr[idx].sh_offset = offset; + grub_util_write_image_at (image + pe_shdr->raw_data_offset, + pe_shdr->raw_data_size, offset, fp); + + offset += pe_shdr->raw_data_size; + } + + if (pe_shdr->relocations_offset) + { + char relname[5 + strlen (name)]; + + if (num_sections >= MAX_SECTIONS) + grub_util_error ("too many sections"); + + sprintf (relname, ".rel%s", name); + + shdr[num_sections].sh_name = insert_string (relname); + shdr[num_sections].sh_link = i; + shdr[num_sections].sh_info = idx; + + shdr[idx].sh_name = shdr[num_sections].sh_name + 4; + + num_sections++; + } + else + shdr[idx].sh_name = insert_string (name); + } + + return section_map; +} + +static void +write_reloc_section (FILE* fp, char *image, + struct grub_pe32_coff_header *pe_chdr, + struct grub_pe32_section_table *pe_shdr, + Elf32_Sym *symtab, + int *symtab_map) +{ + int i; + + for (i = REL_SECTION; i < num_sections; i++) + { + struct grub_pe32_section_table *pe_sec; + struct grub_pe32_reloc *pe_rel; + Elf32_Rel *rel; + int num_rels, j, modified; + + pe_sec = pe_shdr + shdr[i].sh_link; + pe_rel = (struct grub_pe32_reloc *) (image + pe_sec->relocations_offset); + rel = (Elf32_Rel *) xmalloc (pe_sec->num_relocations * sizeof (Elf32_Rel)); + num_rels = 0; + modified = 0; + + for (j = 0; j < pe_sec->num_relocations; j++, pe_rel++) + { + int type; + grub_uint32_t ofs, *addr; + + if ((pe_rel->symtab_index >= pe_chdr->num_symbols) || + (symtab_map[pe_rel->symtab_index] == -1)) + grub_util_error ("invalid symbol"); + + if (pe_rel->type == GRUB_PE32_REL_I386_DIR32) + type = R_386_32; + else if (pe_rel->type == GRUB_PE32_REL_I386_REL32) + type = R_386_PC32; + else + grub_util_error ("unknown pe relocation type %d\n", pe_rel->type); + + ofs = pe_rel->offset - pe_sec->virtual_address; + addr = (grub_uint32_t *)(image + pe_sec->raw_data_offset + ofs); + if (type == R_386_PC32) + { + unsigned char code; + + code = image[pe_sec->raw_data_offset + ofs - 1]; + + if (((code != 0xe8) && (code != 0xe9)) || (*addr)) + grub_util_error ("invalid relocation (%x %x)", code, *addr); + + modified = 1; + if (symtab[symtab_map[pe_rel->symtab_index]].st_shndx) + { + if (symtab[symtab_map[pe_rel->symtab_index]].st_shndx + != shdr[i].sh_info) + grub_util_error ("cross section call is not allowed"); + + *addr = (symtab[symtab_map[pe_rel->symtab_index]].st_value + - ofs - 4); + + continue; + } + else + *addr = -4; + } + + rel[num_rels].r_offset = ofs; + rel[num_rels].r_info = ELF32_R_INFO (symtab_map[pe_rel->symtab_index], + type); + num_rels++; + } + + if (modified) + grub_util_write_image_at (image + pe_sec->raw_data_offset, + shdr[shdr[i].sh_info].sh_size, + shdr[shdr[i].sh_info].sh_offset, + fp); + + shdr[i].sh_type = SHT_REL; + shdr[i].sh_offset = offset; + shdr[i].sh_link = SYMTAB_SECTION; + shdr[i].sh_addralign = 4; + shdr[i].sh_entsize = sizeof (Elf32_Rel); + shdr[i].sh_size = num_rels * sizeof (Elf32_Rel); + + grub_util_write_image_at (rel, shdr[i].sh_size, offset, fp); + offset += shdr[i].sh_size; + free (rel); + } +} + +static void +write_symbol_table (FILE* fp, char *image, + struct grub_pe32_coff_header *pe_chdr, + struct grub_pe32_section_table *pe_shdr, + int *section_map) +{ + struct grub_pe32_symbol *pe_symtab; + char *pe_strtab; + Elf32_Sym *symtab; + int *symtab_map, num_syms; + int i; + + pe_symtab = (struct grub_pe32_symbol *) (image + pe_chdr->symtab_offset); + pe_strtab = (char *) (pe_symtab + pe_chdr->num_symbols); + + symtab = (Elf32_Sym *) xmalloc ((pe_chdr->num_symbols + 1) * + sizeof (Elf32_Sym)); + memset (symtab, 0, (pe_chdr->num_symbols + 1) * sizeof (Elf32_Sym)); + num_syms = 1; + + symtab_map = (int *) xmalloc (pe_chdr->num_symbols * sizeof (int)); + + for (i = 0; i < (int) pe_chdr->num_symbols; + i += pe_symtab->num_aux + 1, pe_symtab += pe_symtab->num_aux + 1) + { + int bind, type; + + symtab_map[i] = -1; + if ((pe_symtab->section > pe_chdr->num_sections) || + (section_map[pe_symtab->section] == -1)) + continue; + + if (! pe_symtab->section) + type = STT_NOTYPE; + else if (pe_symtab->type == GRUB_PE32_DT_FUNCTION) + type = STT_FUNC; + else + type = STT_OBJECT; + + if (pe_symtab->storage_class == GRUB_PE32_SYM_CLASS_EXTERNAL) + bind = STB_GLOBAL; + else + bind = STB_LOCAL; + + if ((pe_symtab->type != GRUB_PE32_DT_FUNCTION) && (pe_symtab->num_aux)) + { + if (! pe_symtab->value) + type = STT_SECTION; + + symtab[num_syms].st_name = shdr[section_map[pe_symtab->section]].sh_name; + } + else + { + char short_name[9]; + char *name; + + if (pe_symtab->long_name[0]) + { + strncpy (short_name, pe_symtab->short_name, 8); + short_name[8] = 0; + name = short_name; + } + else + name = pe_strtab + pe_symtab->long_name[1]; + + if ((strcmp (name, "_grub_mod_init")) && + (strcmp (name, "_grub_mod_fini")) && + (bind == STB_LOCAL)) + continue; + + symtab[num_syms].st_name = insert_string (name); + } + + symtab[num_syms].st_shndx = section_map[pe_symtab->section]; + symtab[num_syms].st_value = pe_symtab->value; + symtab[num_syms].st_info = ELF32_ST_INFO (bind, type); + + symtab_map[i] = num_syms; + num_syms++; + } + + write_reloc_section (fp, image, pe_chdr, pe_shdr, symtab, symtab_map); + + shdr[SYMTAB_SECTION].sh_name = insert_string (".symtab"); + shdr[SYMTAB_SECTION].sh_type = SHT_SYMTAB; + shdr[SYMTAB_SECTION].sh_offset = offset; + shdr[SYMTAB_SECTION].sh_size = num_syms * sizeof (Elf32_Sym); + shdr[SYMTAB_SECTION].sh_entsize = sizeof (Elf32_Sym); + shdr[SYMTAB_SECTION].sh_link = STRTAB_SECTION; + shdr[SYMTAB_SECTION].sh_addralign = 4; + + grub_util_write_image_at (symtab, shdr[SYMTAB_SECTION].sh_size, + offset, fp); + offset += shdr[SYMTAB_SECTION].sh_size; + + free (symtab); + free (symtab_map); +} + +static void +write_string_table (FILE* fp) +{ + shdr[STRTAB_SECTION].sh_name = insert_string (".strtab"); + shdr[STRTAB_SECTION].sh_type = SHT_STRTAB; + shdr[STRTAB_SECTION].sh_offset = offset; + shdr[STRTAB_SECTION].sh_size = strtab_len; + shdr[STRTAB_SECTION].sh_addralign = 1; + grub_util_write_image_at (strtab, strtab_len, offset, fp); + offset += strtab_len; + + free (strtab); +} + +static void +write_section_header (FILE* fp) +{ + ehdr.e_ident[EI_MAG0] = ELFMAG0; + ehdr.e_ident[EI_MAG1] = ELFMAG1; + ehdr.e_ident[EI_MAG2] = ELFMAG2; + ehdr.e_ident[EI_MAG3] = ELFMAG3; + ehdr.e_ident[EI_VERSION] = EV_CURRENT; + ehdr.e_version = EV_CURRENT; + ehdr.e_type = ET_REL; + + ehdr.e_ident[EI_CLASS] = ELFCLASS32; + ehdr.e_ident[EI_DATA] = ELFDATA2LSB; + ehdr.e_machine = EM_386; + + ehdr.e_ehsize = sizeof (ehdr); + ehdr.e_shentsize = sizeof (Elf32_Shdr); + ehdr.e_shstrndx = STRTAB_SECTION; + + ehdr.e_shoff = offset; + ehdr.e_shnum = num_sections; + grub_util_write_image_at (&shdr, sizeof (Elf32_Shdr) * num_sections, + offset, fp); + + grub_util_write_image_at (&ehdr, sizeof (Elf32_Ehdr), 0, fp); +} + +static void +convert_pe (FILE* fp, char *image) +{ + struct grub_pe32_coff_header *pe_chdr; + struct grub_pe32_section_table *pe_shdr; + int *section_map; + + pe_chdr = (struct grub_pe32_coff_header *) image; + if (grub_le_to_cpu16 (pe_chdr->machine) != GRUB_PE32_MACHINE_I386) + grub_util_error ("invalid coff image"); + + strtab = xmalloc (STRTAB_BLOCK); + strtab_max = STRTAB_BLOCK; + strtab[0] = 0; + strtab_len = 1; + + offset = sizeof (ehdr); + pe_shdr = (struct grub_pe32_section_table *) (pe_chdr + 1); + num_sections = REL_SECTION; + + section_map = write_section_data (fp, image, pe_chdr, pe_shdr); + + write_symbol_table (fp, image, pe_chdr, pe_shdr, section_map); + free (section_map); + + write_string_table (fp); + + write_section_header (fp); +} + +int +main (int argc, char *argv[]) +{ + char *image; + FILE* fp; + + set_program_name (argv[0]); + + /* Check for options. */ + while (1) + { + int c = getopt_long (argc, argv, "hVv", options, 0); + + if (c == -1) + break; + else + switch (c) + { + case 'h': + usage (0); + break; + + case 'V': + printf ("%s (%s) %s\n", program_name, PACKAGE_NAME, PACKAGE_VERSION); + return 0; + + case 'v': + verbosity++; + break; + + default: + usage (1); + break; + } + } + + /* Obtain PATH. */ + if (optind >= argc) + { + fprintf (stderr, "Filename not specified.\n"); + usage (1); + } + + image = grub_util_read_image (argv[optind]); + + if (optind + 1 < argc) + optind++; + + fp = fopen (argv[optind], "wb"); + if (! fp) + grub_util_error ("cannot open %s", argv[optind]); + + convert_pe (fp, image); + + fclose (fp); + + return 0; +} |