misc/omfdump.c

   1 /*
   2  * omfdump.c
   3  *
   4  * Very simple program to dump the contents of an OMF (OBJ) file
   5  *
   6  * This assumes a littleendian, unaligned-load-capable host and a
   7  * C compiler which handles basic C99.
   8  */
   9
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <inttypes.h>
  13 #include <ctype.h>
  14 #include <fcntl.h>
  15 #include <unistd.h>
  16 #include <sys/mman.h>
  17 #include <sys/stat.h>
  18
  19 const char *progname;
  20
  21 static const char *record_types[256] =
  22 {
  23     [0x80] = "THEADR",
  24     [0x82] = "LHEADR",
  25     [0x88] = "COMENT",
  26     [0x8a] = "MODEND16",
  27     [0x8b] = "MODEND32",
  28     [0x8c] = "EXTDEF",
  29     [0x90] = "PUBDEF16",
  30     [0x91] = "PUBDEF32",
  31     [0x94] = "LINNUM16",
  32     [0x95] = "LINNUM32",
  33     [0x96] = "LNAMES",
  34     [0x98] = "SEGDEF16",
  35     [0x99] = "SEGDEF32",
  36     [0x9a] = "GRPDEF",
  37     [0x9c] = "FIXUPP16",
  38     [0x9d] = "FIXUPP32",
  39     [0xa0] = "LEDATA16",
  40     [0xa1] = "LEDATA32",
  41     [0xa2] = "LIDATA16",
  42     [0xa3] = "LIDATA32",
  43     [0xb0] = "COMDEF",
  44     [0xb2] = "BAKPAT16",
  45     [0xb3] = "BAKPAT32",
  46     [0xb4] = "LEXTDEF",
  47     [0xb6] = "LPUBDEF16",
  48     [0xb7] = "LPUBDEF32",
  49     [0xb8] = "LCOMDEF",
  50     [0xbc] = "CEXTDEF",
  51     [0xc2] = "COMDAT16",
  52     [0xc3] = "COMDAT32",
  53     [0xc4] = "LINSYM16",
  54     [0xc5] = "LINSYM32",
  55     [0xc6] = "ALIAS",
  56     [0xc8] = "NBKPAT16",
  57     [0xc9] = "NBKPAT32",
  58     [0xca] = "LLNAMES",
  59     [0xcc] = "VERNUM",
  60     [0xce] = "VENDEXT",
  61     [0xf0] = "LIBHDR",
  62     [0xf1] = "LIBEND",
  63 };
  64
  65 typedef void (*dump_func)(uint8_t, const uint8_t *, size_t);
  66
  67 static void hexdump_data(unsigned int offset, const uint8_t *data, size_t n)
  68 {
  69     unsigned int i, j;
  70
  71     for (i = 0; i < n; i += 16) {
  72         printf("  %04x: ", i+offset);
  73         for (j = 0; j < 16; j++) {
  74             if (i+j < n)
  75                 printf("%02x%c", data[i+j], (j == 7) ? '-' : ' ');
  76             else
  77                 printf("   ");
  78         }
  79         printf(" :  ");
  80         for (j = 0; j < 16; j++) {
  81             if (i+j < n)
  82                 putchar(isprint(data[i+j]) ? data[i+j] : '.');
  83         }
  84         putchar('\n');
  85     }
  86 }
  87
  88 static void dump_unknown(uint8_t type, const uint8_t *data, size_t n)
  89 {
  90     (void)type;
  91     hexdump_data(0, data, n);
  92 }
  93
  94 static void dump_coment(uint8_t type, const uint8_t *data, size_t n)
  95 {
  96     uint8_t class;
  97     static const char *coment_class[256] = {
  98         [0x00] = "Translator",
  99         [0x01] = "Copyright",
 100         [0x81] = "Library specifier",
 101         [0x9c] = "MS-DOS version",
 102         [0x9d] = "Memory model",
 103         [0x9e] = "DOSSEG",
 104         [0x9f] = "Library search",
 105         [0xa0] = "OMF extensions",
 106         [0xa1] = "New OMF extension",
 107         [0xa2] = "Link pass separator",
 108         [0xa3] = "LIBMOD",
 109         [0xa4] = "EXESTR",
 110         [0xa6] = "INCERR",
 111         [0xa7] = "NOPAD",
 112         [0xa8] = "WKEXT",
 113         [0xa9] = "LZEXT",
 114         [0xda] = "Comment",
 115         [0xdb] = "Compiler",
 116         [0xdc] = "Date",
 117         [0xdd] = "Timestamp",
 118         [0xdf] = "User",
 119         [0xe9] = "Dependency file",
 120         [0xff] = "Command line"
 121     };
 122
 123     if (n < 2) {
 124         dump_unknown(type, data, n);
 125         return;
 126     }
 127
 128     type  = data[0];
 129     class = data[1];
 130
 131     printf("  [NP=%d NL=%d UD=%02X] %02X %s\n",
 132            (type >> 7) & 1,
 133            (type >> 6) & 1,
 134            type & 0x3f,
 135            class,
 136            coment_class[class] ? coment_class[class] : "???");
 137
 138     hexdump_data(2, data+2, n-2);
 139 }
 140
 141 static const dump_func dump_type[256] =
 142 {
 143     [0x88] = dump_coment,
 144 };
 145
 146 int dump_omf(int fd)
 147 {
 148     struct stat st;
 149     size_t len, n;
 150     uint8_t type;
 151     const uint8_t *p, *data;
 152
 153     if (fstat(fd, &st))
 154         return -1;
 155
 156     len = st.st_size;
 157
 158     data = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0);
 159     if (data == MAP_FAILED)
 160         return -1;
 161
 162     p = data;
 163     while (len >= 3) {
 164         uint8_t csum;
 165         int i;
 166
 167         type = p[0];
 168         n = *(uint16_t *)(p+1);
 169
 170         printf("%02x %-10s %4zd bytes",
 171                type,
 172                record_types[type] ? record_types[type] : "???",
 173                n);
 174
 175         if (len < n+3) {
 176             printf("\n  (truncated, only %zd bytes left)\n", len-3);
 177             break;              /* Truncated */
 178         }
 179
 180         p += 3;       /* Header doesn't count in the length */
 181         n--;          /* Remove checksum byte */
 182
 183         csum = 0;
 184         for (i = -3; i < (int)n; i++)
 185             csum -= p[i];
 186
 187         printf(", checksum %02X", p[i]);
 188         if (csum == p[i])
 189             printf(" (valid)\n");
 190         else
 191             printf(" (actual = %02X)\n", csum);
 192
 193         if (dump_type[type])
 194             dump_type[type](type, p, n);
 195         else
 196             dump_unknown(type, p, n);
 197
 198         p   += n+1;
 199         len -= (n+4);
 200     }
 201
 202     munmap((void *)data, st.st_size);
 203     return 0;
 204 }
 205
 206 int main(int argc, char *argv[])
 207 {
 208     int fd;
 209     int i;
 210
 211     progname = argv[0];
 212
 213     for (i = 1; i < argc; i++) {
 214         fd = open(argv[i], O_RDONLY);
 215         if (fd < 0 || dump_omf(fd)) {
 216             perror(argv[i]);
 217             return 1;
 218         }
 219         close(fd);
 220     }
 221
 222     return 0;
 223 }