loader/macho.c

   1 /* macho.c - load Mach-O files. */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2009  Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 /* This Mach-O loader is incomplete and can load only non-relocatable segments.
  21    This is however enough to boot xnu (otool -l and Mach-O specs for more info).
  22 */
  23
  24 #include <grub/err.h>
  25 #include <grub/macho.h>
  26 #include <grub/cpu/macho.h>
  27 #include <grub/machoload.h>
  28 #include <grub/file.h>
  29 #include <grub/gzio.h>
  30 #include <grub/misc.h>
  31 #include <grub/mm.h>
  32
  33 grub_err_t
  34 grub_macho_close (grub_macho_t macho)
  35 {
  36   grub_file_t file = macho->file;
  37
  38   grub_free (macho->cmds32);
  39   grub_free (macho->cmds64);
  40
  41   grub_free (macho);
  42
  43   if (file)
  44     grub_file_close (file);
  45
  46   return grub_errno;
  47 }
  48
  49 grub_macho_t
  50 grub_macho_file (grub_file_t file)
  51 {
  52   grub_macho_t macho;
  53   union grub_macho_filestart filestart;
  54
  55   macho = grub_malloc (sizeof (*macho));
  56   if (! macho)
  57     return 0;
  58
  59   macho->file = file;
  60   macho->offset32 = -1;
  61   macho->offset64 = -1;
  62   macho->end32 = -1;
  63   macho->end64 = -1;
  64   macho->cmds32 = 0;
  65   macho->cmds64 = 0;
  66
  67   if (grub_file_seek (macho->file, 0) == (grub_off_t) -1)
  68     goto fail;
  69
  70   if (grub_file_read (macho->file, &filestart, sizeof (filestart))
  71       != sizeof (filestart))
  72     {
  73       grub_error_push ();
  74       grub_error (GRUB_ERR_READ_ERROR, "cannot read Mach-O header");
  75       goto fail;
  76     }
  77
  78   /* Is it a fat file? */
  79   if (filestart.fat.magic == grub_be_to_cpu32 (GRUB_MACHO_FAT_MAGIC))
  80     {
  81       struct grub_macho_fat_arch *archs;
  82       int i, narchs;
  83
  84       /* Load architecture description. */
  85       narchs = grub_be_to_cpu32 (filestart.fat.nfat_arch);
  86       if (grub_file_seek (macho->file, sizeof (struct grub_macho_fat_header))
  87           == (grub_off_t) -1)
  88         goto fail;
  89       archs = grub_malloc (sizeof (struct grub_macho_fat_arch) * narchs);
  90       if (!archs)
  91         goto fail;
  92       if (grub_file_read (macho->file, archs,
  93                           sizeof (struct grub_macho_fat_arch) * narchs)
  94           != (grub_ssize_t)sizeof(struct grub_macho_fat_arch) * narchs)
  95         {
  96           grub_free (archs);
  97           grub_error_push ();
  98           grub_error (GRUB_ERR_READ_ERROR, "cannot read Mach-O header");
  99           goto fail;
 100         }
 101
 102       for (i = 0; i < narchs; i++)
 103         {
 104           if (GRUB_MACHO_CPUTYPE_IS_HOST32
 105               (grub_be_to_cpu32 (archs[i].cputype)))
 106             {
 107               macho->offset32 = grub_be_to_cpu32 (archs[i].offset);
 108               macho->end32 = grub_be_to_cpu32 (archs[i].offset)
 109                 + grub_be_to_cpu32 (archs[i].size);
 110             }
 111           if (GRUB_MACHO_CPUTYPE_IS_HOST64
 112               (grub_be_to_cpu32 (archs[i].cputype)))
 113             {
 114               macho->offset64 = grub_be_to_cpu32 (archs[i].offset);
 115               macho->end64 = grub_be_to_cpu32 (archs[i].offset)
 116                 + grub_be_to_cpu32 (archs[i].size);
 117             }
 118         }
 119       grub_free (archs);
 120     }
 121
 122   /* Is it a thin 32-bit file? */
 123   if (filestart.thin32.magic == GRUB_MACHO_MAGIC32)
 124     {
 125       macho->offset32 = 0;
 126       macho->end32 = grub_file_size (file);
 127     }
 128
 129   /* Is it a thin 64-bit file? */
 130   if (filestart.thin64.magic == GRUB_MACHO_MAGIC64)
 131     {
 132       macho->offset64 = 0;
 133       macho->end64 = grub_file_size (file);
 134     }
 135
 136   grub_macho_parse32 (macho);
 137   grub_macho_parse64 (macho);
 138
 139   return macho;
 140
 141 fail:
 142   grub_macho_close (macho);
 143   return 0;
 144 }
 145
 146 grub_macho_t
 147 grub_macho_open (const char *name)
 148 {
 149   grub_file_t file;
 150   grub_macho_t macho;
 151
 152   file = grub_gzfile_open (name, 1);
 153   if (! file)
 154     return 0;
 155
 156   macho = grub_macho_file (file);
 157   if (! macho)
 158     grub_file_close (file);
 159
 160   return macho;
 161 }