contrib/rom-scan/rom-scan.c

   1 #include <fcntl.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <errno.h>
   5 #ifndef __TURBOC__
   6 #include <sys/mman.h>
   7 #include <sys/stat.h>
   8 #include <sys/types.h>
   9 #include <unistd.h>
  10 #endif
  11
  12 #ifdef  __TURBOC__
  13 #define HUGE    huge
  14 #else
  15 #define HUGE
  16 #endif
  17
  18 #define ROMSTART     0xC8000
  19 #define ROMEND       0xE8000
  20 #define ROMINCREMENT 0x00800
  21 #define ROMMASK      0x03FFF
  22
  23 #ifndef MAP_FAILED
  24 #define MAP_FAILED ((void *)(long long)-1)
  25 #endif
  26
  27 typedef struct Images {
  28   struct Images *next;
  29   long           start;
  30   long           size;
  31 } Images;
  32
  33 static void rom_scan(const unsigned char HUGE *rom,long offset,long len)
  34 {
  35   static Images *images = NULL;
  36   Images *ptr;
  37 /* The assignments to dummy are to overcome a bug in TurboC */
  38   long dummy, size;
  39   int chksum;
  40   long i;
  41
  42   if (rom[offset] != 0x55 || rom[dummy = offset+1] != 0xAA)
  43     return;
  44   size = (long)rom[dummy = offset+2]*512L;
  45   printf("Found ROM header at %04lX:0000; "
  46          "announces %ldk image (27C%02d EPROM)\n",
  47          offset/16,(size+512)/1024,
  48          size <=  1024 ?   8 :
  49          size <=  2048 ?  16 :
  50          size <=  4096 ?  32 :
  51          size <=  8192 ?  64 :
  52          size <= 16384 ? 128 :
  53          size <= 32768 ? 256 :
  54          size <= 65536 ? 512 : 11);
  55   if (offset & ROMMASK)
  56     printf("  This is a unusual position; not all BIOSs might find it.\n"
  57            "   Try to move to a 16kB boundary.\n");
  58   if (size > len) {
  59     printf("  This image extends beyond %04X:0000. "
  60            "It clashes with the system BIOS\n",
  61            ROMEND/16);
  62     size = len; }
  63   for (chksum=0, i = size; i--; chksum += rom[dummy = offset+i]);
  64   if (chksum % 256)
  65     printf("  Checksum does not match. This image is not active\n");
  66   ptr        = malloc(sizeof(Images));
  67   ptr->next  = images;
  68   ptr->start = offset;
  69   ptr->size  = size;
  70   images     = ptr;
  71   for (ptr = ptr->next; ptr != NULL; ptr = ptr->next) {
  72     for (i = 0; i < size && i < ptr->size; i++)
  73       if (rom[dummy = ptr->start+i] != rom[dummy = offset+i])
  74         break;
  75     if (i > 32) {
  76       printf("   Image is identical with image at %04lX:0000 "
  77              "for the first %ld bytes\n",
  78              ptr->start/16,i);
  79       if (i >= 1024)
  80         if (i == size)
  81           printf("    this means that you misconfigured the EPROM size!\n");
  82         else
  83           printf("    this could suggest that you misconfigured the "
  84                  "EPROM size\n");
  85       else
  86         printf("    this is probably harmless. Just ignore it...\n"); } }
  87   return;
  88 }
  89
  90 int main(void)
  91 {
  92   long  i;
  93   unsigned char HUGE *rom;
  94
  95 #ifndef __TURBOC__
  96   int   fh;
  97   if ((fh = open("/dev/kmem",O_RDONLY|O_SYNC)) < 0) {
  98     fprintf(stderr,"Could not open \"/dev/kmem\": %s\n",0 );//strerror(errno));
  99     return(1); }
 100   if ((rom = mmap(NULL,ROMEND-ROMSTART,PROT_READ,MAP_SHARED,fh,
 101                   ROMSTART)) == MAP_FAILED) {
 102     fprintf(stderr,"Could not mmap \"/dev/kmem\": %s\n",0); //strerror(errno));
 103     close(fh);
 104     return(1); }
 105   close(fh);
 106 #endif
 107   for (i = ROMEND; (i -= ROMINCREMENT) >= ROMSTART; )
 108 #ifdef  __TURBOC__
 109     rom_scan(0,i,ROMEND-i);
 110 #else
 111     rom_scan(rom-ROMSTART,i,ROMEND-i);
 112   munmap(rom,ROMEND-ROMSTART);
 113 #endif
 114   return(0);
 115 }