From 5a11f59a828e3a39d101282d884d188630316ea8 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Wed, 1 Jul 2009 23:11:15 -0700 Subject: [PATCH] Beginnings of a crude utility to dump the contents of an OMF file Beginnings of a crude utility to dump the contents of an OMF (obj) file. At this point all it does it breaks it down into the individual records and dumps those, but it is still easier to read than a pure hexdump. See http://www.azillionmonkeys.com/qed/Omfg.pdf for the format spec. Signed-off-by: H. Peter Anvin --- misc/omfdump.c | 223 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 223 insertions(+) create mode 100644 misc/omfdump.c diff --git a/misc/omfdump.c b/misc/omfdump.c new file mode 100644 index 00000000..322971e9 --- /dev/null +++ b/misc/omfdump.c @@ -0,0 +1,223 @@ +/* + * omfdump.c + * + * Very simple program to dump the contents of an OMF (OBJ) file + * + * This assumes a littleendian, unaligned-load-capable host and a + * C compiler which handles basic C99. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +const char *progname; + +static const char *record_types[256] = +{ + [0x80] = "THEADR", + [0x82] = "LHEADR", + [0x88] = "COMENT", + [0x8a] = "MODEND16", + [0x8b] = "MODEND32", + [0x8c] = "EXTDEF", + [0x90] = "PUBDEF16", + [0x91] = "PUBDEF32", + [0x94] = "LINNUM16", + [0x95] = "LINNUM32", + [0x96] = "LNAMES", + [0x98] = "SEGDEF16", + [0x99] = "SEGDEF32", + [0x9a] = "GRPDEF", + [0x9c] = "FIXUPP16", + [0x9d] = "FIXUPP32", + [0xa0] = "LEDATA16", + [0xa1] = "LEDATA32", + [0xa2] = "LIDATA16", + [0xa3] = "LIDATA32", + [0xb0] = "COMDEF", + [0xb2] = "BAKPAT16", + [0xb3] = "BAKPAT32", + [0xb4] = "LEXTDEF", + [0xb6] = "LPUBDEF16", + [0xb7] = "LPUBDEF32", + [0xb8] = "LCOMDEF", + [0xbc] = "CEXTDEF", + [0xc2] = "COMDAT16", + [0xc3] = "COMDAT32", + [0xc4] = "LINSYM16", + [0xc5] = "LINSYM32", + [0xc6] = "ALIAS", + [0xc8] = "NBKPAT16", + [0xc9] = "NBKPAT32", + [0xca] = "LLNAMES", + [0xcc] = "VERNUM", + [0xce] = "VENDEXT", + [0xf0] = "LIBHDR", + [0xf1] = "LIBEND", +}; + +typedef void (*dump_func)(uint8_t, const uint8_t *, size_t); + +static void hexdump_data(unsigned int offset, const uint8_t *data, size_t n) +{ + unsigned int i, j; + + for (i = 0; i < n; i += 16) { + printf(" %04x: ", i+offset); + for (j = 0; j < 16; j++) { + if (i+j < n) + printf("%02x%c", data[i+j], (j == 7) ? '-' : ' '); + else + printf(" "); + } + printf(" : "); + for (j = 0; j < 16; j++) { + if (i+j < n) + putchar(isprint(data[i+j]) ? data[i+j] : '.'); + } + putchar('\n'); + } +} + +static void dump_unknown(uint8_t type, const uint8_t *data, size_t n) +{ + (void)type; + hexdump_data(0, data, n); +} + +static void dump_coment(uint8_t type, const uint8_t *data, size_t n) +{ + uint8_t class; + static const char *coment_class[256] = { + [0x00] = "Translator", + [0x01] = "Copyright", + [0x81] = "Library specifier", + [0x9c] = "MS-DOS version", + [0x9d] = "Memory model", + [0x9e] = "DOSSEG", + [0x9f] = "Library search", + [0xa0] = "OMF extensions", + [0xa1] = "New OMF extension", + [0xa2] = "Link pass separator", + [0xa3] = "LIBMOD", + [0xa4] = "EXESTR", + [0xa6] = "INCERR", + [0xa7] = "NOPAD", + [0xa8] = "WKEXT", + [0xa9] = "LZEXT", + [0xda] = "Comment", + [0xdb] = "Compiler", + [0xdc] = "Date", + [0xdd] = "Timestamp", + [0xdf] = "User", + [0xe9] = "Dependency file", + [0xff] = "Command line" + }; + + if (n < 2) { + dump_unknown(type, data, n); + return; + } + + type = data[0]; + class = data[1]; + + printf(" [NP=%d NL=%d UD=%02X] %02X %s\n", + (type >> 7) & 1, + (type >> 6) & 1, + type & 0x3f, + class, + coment_class[class] ? coment_class[class] : "???"); + + hexdump_data(2, data+2, n-2); +} + +static const dump_func dump_type[256] = +{ + [0x88] = dump_coment, +}; + +int dump_omf(int fd) +{ + struct stat st; + size_t len, n; + uint8_t type; + const uint8_t *p, *data; + + if (fstat(fd, &st)) + return -1; + + len = st.st_size; + + data = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0); + if (data == MAP_FAILED) + return -1; + + p = data; + while (len >= 3) { + uint8_t csum; + int i; + + type = p[0]; + n = *(uint16_t *)(p+1); + + printf("%02x %-10s %4zd bytes", + type, + record_types[type] ? record_types[type] : "???", + n); + + if (len < n+3) { + printf("\n (truncated, only %zd bytes left)\n", len-3); + break; /* Truncated */ + } + + p += 3; /* Header doesn't count in the length */ + n--; /* Remove checksum byte */ + + csum = 0; + for (i = -3; i < (int)n; i++) + csum -= p[i]; + + printf(", checksum %02X", p[i]); + if (csum == p[i]) + printf(" (valid)\n"); + else + printf(" (actual = %02X)\n", csum); + + if (dump_type[type]) + dump_type[type](type, p, n); + else + dump_unknown(type, p, n); + + p += n+1; + len -= (n+4); + } + + munmap((void *)data, st.st_size); + return 0; +} + +int main(int argc, char *argv[]) +{ + int fd; + int i; + + progname = argv[0]; + + for (i = 1; i < argc; i++) { + fd = open(argv[i], O_RDONLY); + if (fd < 0 || dump_omf(fd)) { + perror(argv[i]); + return 1; + } + close(fd); + } + + return 0; +} -- 2.11.4.GIT