src/libexec/elf.c

   1 /*
   2  * <elf.c>
   3  *
   4  * Open Hack'Ware BIOS ELF executable file loader
   5  *
   6  * Copyright (c) 2004-2005 Jocelyn Mayer
   7  *
   8  *   This program is free software; you can redistribute it and/or
   9  *   modify it under the terms of the GNU General Public License V2
  10  *   as published by the Free Software Foundation
  11  *
  12  *   This program is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with this program; if not, write to the Free Software
  19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include "bios.h"
  25 #include "exec.h"
  26
  27 uint32_t fs_inode_get_size (inode_t *inode);
  28
  29 /* ELF executable loader */
  30 typedef uint16_t Elf32_Half;
  31 typedef uint32_t Elf32_Word;
  32 typedef uint32_t Elf32_Off;
  33 typedef uint32_t Elf32_Addr;
  34
  35 #define EI_NIDENT       16
  36
  37 typedef struct elf32_hdr_t {
  38   unsigned char e_ident[EI_NIDENT];
  39   Elf32_Half    e_type;
  40   Elf32_Half    e_machine;
  41   Elf32_Word    e_version;
  42   Elf32_Addr    e_entry;  /* Entry point */
  43   Elf32_Off     e_phoff;
  44   Elf32_Off     e_shoff;
  45   Elf32_Word    e_flags;
  46   Elf32_Half    e_ehsize;
  47   Elf32_Half    e_phentsize;
  48   Elf32_Half    e_phnum;
  49   Elf32_Half    e_shentsize;
  50   Elf32_Half    e_shnum;
  51   Elf32_Half    e_shstrndx;
  52 } Elf32_Ehdr_t;
  53
  54 typedef struct elf32_phdr_t {
  55   Elf32_Word    p_type;
  56   Elf32_Off     p_offset;
  57   Elf32_Addr    p_vaddr;
  58   Elf32_Addr    p_paddr;
  59   Elf32_Word    p_filesz;
  60   Elf32_Word    p_memsz;
  61   Elf32_Word    p_flags;
  62   Elf32_Word    p_align;
  63 } Elf32_Phdr_t;
  64
  65 #define EI_MAG0         0               /* e_ident[] indexes */
  66 #define EI_MAG1         1
  67 #define EI_MAG2         2
  68 #define EI_MAG3         3
  69 #define EI_CLASS        4
  70 #define EI_DATA         5
  71 #define EI_VERSION      6
  72 #define EI_OSABI        7
  73 #define EI_PAD          8
  74
  75 #define ELFMAG0         0x7f            /* EI_MAG */
  76 #define ELFMAG1         'E'
  77 #define ELFMAG2         'L'
  78 #define ELFMAG3         'F'
  79
  80 #define ELFCLASSNONE    0               /* EI_CLASS */
  81 #define ELFCLASS32      1
  82 #define ELFCLASS64      2
  83 #define ELFCLASSNUM     3
  84
  85 #define ELFDATANONE     0               /* e_ident[EI_DATA] */
  86 #define ELFDATA2LSB     1
  87 #define ELFDATA2MSB     2
  88
  89 #define EV_NONE         0               /* e_version, EI_VERSION */
  90 #define EV_CURRENT      1
  91 #define EV_NUM          2
  92
  93 /* These constants define the different elf file types */
  94 #define ET_NONE   0
  95 #define ET_REL    1
  96 #define ET_EXEC   2
  97 #define ET_DYN    3
  98 #define ET_CORE   4
  99 #define ET_LOPROC 0xff00
 100 #define ET_HIPROC 0xffff
 101
 102 /* These constants define the various ELF target machines */
 103 #define EM_NONE  0
 104 #define EM_M32   1
 105 #define EM_SPARC 2
 106 #define EM_386   3
 107 #define EM_68K   4
 108 #define EM_88K   5
 109 #define EM_486   6   /* Perhaps disused */
 110 #define EM_860   7
 111 #define EM_MIPS         8       /* MIPS R3000 (officially, big-endian only) */
 112 #define EM_MIPS_RS4_BE 10       /* MIPS R4000 big-endian */
 113 #define EM_PARISC      15       /* HPPA */
 114 #define EM_SPARC32PLUS 18       /* Sun's "v8plus" */
 115 #define EM_PPC         20       /* PowerPC */
 116 #define EM_PPC64       21       /* PowerPC64 */
 117 #define EM_SH          42       /* SuperH */
 118 #define EM_SPARCV9     43       /* SPARC v9 64-bit */
 119 #define EM_IA_64        50      /* HP/Intel IA-64 */
 120 #define EM_X86_64       62      /* AMD x86-64 */
 121 #define EM_S390         22      /* IBM S/390 */
 122 #define EM_CRIS         76      /* Axis Communications 32-bit embedded processor */
 123 #define EM_V850         87      /* NEC v850 */
 124 #define EM_H8_300H      47      /* Hitachi H8/300H */
 125 #define EM_H8S          48      /* Hitachi H8S     */
 126 /*
 127  * This is an interim value that we will use until the committee comes
 128  * up with a final number.
 129  */
 130 #define EM_ALPHA        0x9026
 131 /* Bogus old v850 magic number, used by old tools.  */
 132 #define EM_CYGNUS_V850  0x9080
 133 /*
 134  * This is the old interim value for S/390 architecture
 135  */
 136 #define EM_S390_OLD     0xA390
 137
 138 int exec_load_elf (inode_t *file, void **dest, void **entry, void **end,
 139                    uint32_t loffset)
 140 {
 141     Elf32_Ehdr_t ehdr;
 142     Elf32_Phdr_t phdr;
 143     void *address, *first, *last;
 144     uint32_t offset, fsize, msize;
 145     int i;
 146
 147     file_seek(file, loffset);
 148     if (fs_read(file, &ehdr, sizeof(Elf32_Ehdr_t)) < 0) {
 149         ERROR("Cannot load first bloc of file...\n");
 150         return -1;
 151     }
 152     DPRINTF("Check ELF file\n");
 153     /* Check ident */
 154     if (ehdr.e_ident[EI_MAG0] != ELFMAG0 ||
 155         ehdr.e_ident[EI_MAG1] != ELFMAG1 ||
 156         ehdr.e_ident[EI_MAG2] != ELFMAG2 ||
 157         ehdr.e_ident[EI_MAG3] != ELFMAG3) {
 158         DPRINTF("Not an ELF file %0x\n", *(uint32_t *)ehdr.e_ident);
 159         return -2;
 160     }
 161     if (ehdr.e_ident[EI_CLASS] != ELFCLASS32) {
 162         ERROR("Not a 32 bits ELF file\n");
 163         return -2;
 164     }
 165     if (ehdr.e_ident[EI_DATA] != ELFDATA2MSB) {
 166         ERROR("Not a big-endian ELF file\n");
 167         return -2;
 168     }
 169     if (ehdr.e_ident[EI_VERSION] != EV_CURRENT /*||
 170         ehdr->e_version != EV_CURRENT*/) {
 171         ERROR("Invalid ELF executable version %d %08x\n",
 172               ehdr.e_ident[EI_VERSION], ehdr.e_version);
 173         return -2;
 174     }
 175     if (ehdr.e_type != ET_EXEC) {
 176         ERROR("Not an executable ELF file\n");
 177         return -2;
 178     }
 179     if (ehdr.e_machine != EM_PPC) {
 180         ERROR("Not a PPC ELF executable\n");
 181         return -2;
 182     }
 183     /* All right, seems to be a regular ELF program for PPC */
 184     *entry = (void *)ehdr.e_entry;
 185     DPRINTF("ELF file found entry = %p\n", *entry);
 186     last = NULL;
 187     first = last - 4;
 188     fsize = msize = 0;
 189     offset = ehdr.e_phoff;
 190     for (i = 0; i < ehdr.e_phnum; i++) {
 191 #if 0
 192         if (offset > fs_inode_get_size(file)) {
 193             ERROR("ELF program header %d offset > file size %d %d\n", i,
 194                   offset, fs_inode_get_size(file));
 195             return -1;
 196         }
 197 #endif
 198         DPRINTF("Load program header %d from %08x\n", i, offset);
 199         file_seek(file, offset + loffset);
 200         if (fs_read(file, &phdr, sizeof(Elf32_Phdr_t)) < 0) {
 201             ERROR("Cannot load ELF program header %d...\n", i);
 202             return -1;
 203         }
 204         DPRINTF("Load program header %d %08x %08x %08x %08x\n", i,
 205                 phdr.p_offset, phdr.p_vaddr, phdr.p_filesz, phdr.p_memsz);
 206 #if 0
 207         if (phdr.p_offset > fs_inode_get_size(file)) {
 208             ERROR("ELF program %d offset > file size %d %d\n",
 209                   i, phdr.p_offset, fs_inode_get_size(file));
 210             return -1;
 211         }
 212 #endif
 213         /* As we won't remap memory, load it at it's virtual address (!) */
 214         address = (void *)phdr.p_vaddr;
 215         if (address < first)
 216             first = address;
 217         fsize = phdr.p_filesz;
 218         msize = phdr.p_memsz;
 219         if (address + msize > last)
 220             last = address + msize;
 221         file_seek(file, phdr.p_offset + loffset);
 222         set_loadinfo((void *)first, last - first);
 223         if (fs_read(file, address, fsize) < 0) {
 224             ERROR("Cannot load ELF program %d...\n", i);
 225             return -1;
 226         }
 227         if (msize > fsize) {
 228             memset(address + fsize, 0, msize - fsize);
 229         }
 230         offset += ehdr.e_phentsize;
 231     }
 232     *dest = (void *)first;
 233     *end = (void *)last;
 234     DPRINTF("ELF file loaded at %p => %p fsize %08x msize %08x "
 235             "(%08x %08x)\n", *dest, *entry, fsize, msize,
 236             *(uint32_t *)entry, *((uint32_t *)entry + 1));
 237
 238     return 0;
 239 }