usr/src/grub/grub-0.97/util/mbchk.c

   1 /* mbchk - a simple checker for the format of a Multiboot kernel */
   2 /*
   3  *  Copyright (C) 1999,2001,2002  Free Software Foundation, Inc.
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19
  20 #include <config.h>
  21
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <getopt.h>
  25 #include <multiboot.h>
  26
  27 static int quiet = 0;
  28 static char *optstring = "hvq";
  29 static struct option longopts[] =
  30 {
  31   {"help", no_argument, 0, 'h'},
  32   {"version", no_argument, 0, 'v'},
  33   {"quiet", no_argument, 0, 'q'},
  34   {0}
  35 };
  36
  37 static void
  38 usage (int status)
  39 {
  40   if (status)
  41     fprintf (stderr, "Try ``mbchk --help'' for more information.\n");
  42   else
  43     printf ("Usage: mbchk [OPTION]... [FILE]...\n"
  44             "Check if the format of FILE complies with the Multiboot Specification.\n"
  45             "\n"
  46             "-q, --quiet                suppress all normal output\n"
  47             "-h, --help                 display this help and exit\n"
  48             "-v, --version              output version information and exit.\n"
  49             "\n"
  50             "Report bugs to <bug-grub@gnu.org>.\n");
  51
  52   exit (status);
  53 }
  54
  55 static int
  56 check_multiboot (const char *filename, FILE *fp)
  57 {
  58   multiboot_header_t *mbh = 0;
  59   int i;
  60   char buf[8192];
  61
  62   if (fread (buf, 1, 8192, fp) < 0)
  63     {
  64       fprintf (stderr, "%s: Read error.\n", filename);
  65       return 0;
  66     }
  67
  68   for (i = 0; i < 8192 - sizeof (multiboot_header_t); i++)
  69     {
  70       unsigned long magic = *((unsigned long *) (buf + i));
  71
  72       if (magic == MULTIBOOT_HEADER_MAGIC)
  73         {
  74           mbh = (multiboot_header_t *) (buf + i);
  75           break;
  76         }
  77     }
  78
  79   if (! mbh)
  80     {
  81       fprintf (stderr, "%s: No Multiboot header.\n", filename);
  82       return 0;
  83     }
  84
  85   if (! quiet)
  86     printf ("%s: The Multiboot header is found at the offset %d.\n",
  87             filename, i);
  88
  89   /* Check for the checksum.  */
  90   if (mbh->magic + mbh->flags + mbh->checksum != 0)
  91     {
  92       fprintf (stderr,
  93                "%s: Bad checksum (0x%lx).\n",
  94                filename, mbh->checksum);
  95       return 0;
  96     }
  97
  98   /* Reserved flags must be zero.  */
  99   if (mbh->flags & ~0x00010003)
 100     {
 101       fprintf (stderr,
 102                "%s: Non-zero is found in reserved flags (0x%lx).\n",
 103                filename, mbh->flags);
 104       return 0;
 105     }
 106
 107   if (! quiet)
 108     {
 109       printf ("%s: Page alignment is turned %s.\n",
 110               filename, (mbh->flags & 0x1)? "on" : "off");
 111       printf ("%s: Memory information is turned %s.\n",
 112               filename, (mbh->flags & 0x2)? "on" : "off");
 113       printf ("%s: Address fields is turned %s.\n",
 114               filename, (mbh->flags & 0x10000)? "on" : "off");
 115     }
 116
 117   /* Check for the address fields.  */
 118   if (mbh->flags & 0x10000)
 119     {
 120       if (mbh->header_addr < mbh->load_addr)
 121         {
 122           fprintf (stderr,
 123                    "%s: header_addr is less than "
 124                    "load_addr (0x%lx > 0x%lx).\n",
 125                    filename, mbh->header_addr, mbh->load_addr);
 126           return 0;
 127         }
 128
 129       if (mbh->load_end_addr && mbh->load_addr >= mbh->load_end_addr)
 130         {
 131           fprintf (stderr,
 132                    "%s: load_addr is not less than load_end_addr"
 133                    " (0x%lx >= 0x%lx).\n",
 134                    filename, mbh->load_addr, mbh->load_end_addr);
 135           return 0;
 136         }
 137
 138       if (mbh->bss_end_addr && mbh->load_end_addr > mbh->bss_end_addr)
 139         {
 140           fprintf (stderr,
 141                    "%s: load_end_addr is greater than bss_end_addr"
 142                    " (0x%lx > 0x%lx).\n",
 143                    filename, mbh->load_end_addr, mbh->bss_end_addr);
 144           return 0;
 145         }
 146
 147       if (mbh->load_addr > mbh->entry_addr)
 148         {
 149           fprintf (stderr,
 150                    "%s: load_addr is greater than entry_addr"
 151                    " (0x%lx > 0x%lx).\n",
 152                    filename, mbh->load_addr, mbh->entry_addr);
 153           return 0;
 154         }
 155
 156       /* FIXME: It is better to check if the entry address is within the
 157          file, especially when the load end address is zero.  */
 158       if (mbh->load_end_addr && mbh->load_end_addr <= mbh->entry_addr)
 159         {
 160           fprintf (stderr,
 161                    "%s: load_end_addr is not greater than entry_addr"
 162                    " (0x%lx <= 0x%lx).\n",
 163                    filename, mbh->load_end_addr, mbh->entry_addr);
 164           return 0;
 165         }
 166
 167       /* This is a GRUB-specific limitation.  */
 168       if (mbh->load_addr < 0x100000)
 169         {
 170           fprintf (stderr,
 171                    "%s: Cannot be loaded at less than 1MB by GRUB"
 172                    " (0x%lx).\n",
 173                    filename, mbh->load_addr);
 174           return 0;
 175         }
 176     }
 177
 178   if (! quiet)
 179     printf ("%s: All checks passed.\n", filename);
 180
 181   return 1;
 182 }
 183
 184 int
 185 main (int argc, char *argv[])
 186 {
 187   int c;
 188
 189   do
 190     {
 191       c = getopt_long (argc, argv, optstring, longopts, 0);
 192       switch (c)
 193         {
 194         case EOF:
 195           break;
 196
 197         case 'h':
 198           usage (0);
 199           break;
 200
 201         case 'v':
 202           printf ("mbchk (GNU GRUB " VERSION ")\n");
 203           exit (0);
 204           break;
 205
 206         case 'q':
 207           quiet = 1;
 208           break;
 209
 210         default:
 211           usage (1);
 212           break;
 213         }
 214     }
 215   while (c != EOF);
 216
 217   if (optind < argc)
 218     {
 219       while (optind < argc)
 220         {
 221           FILE *fp;
 222
 223           fp = fopen (argv[optind], "r");
 224           if (! fp)
 225             {
 226               fprintf (stderr, "%s: No such file.\n", argv[optind]);
 227               exit (1);
 228             }
 229
 230           if (! check_multiboot (argv[optind], fp))
 231             exit (1);
 232
 233           fclose (fp);
 234           optind++;
 235         }
 236     }
 237   else
 238     {
 239       if (! check_multiboot ("<stdin>", stdin))
 240         exit (1);
 241     }
 242
 243   return 0;
 244 }