sys/arch/i386/stand/genprom/genprom.c

   1 /*      $NetBSD: genprom.c,v 1.7 2007/12/25 18:33:33 perry Exp $         */
   2
   3 /*
   4  * mainly from netbsd:sys/arch/i386/netboot/genprom.c
   5  */
   6
   7 /*
   8  * Read a binary image of a bios extension, generate the
   9  * appropriate block count and checksum and write them
  10  * into the rom image (replacing 2nd and 5th bytes)
  11  * The binary image should be sized before being filtered
  12  * through this routine.
  13  */
  14
  15 #include <stdio.h>
  16 #include <string.h>
  17 #include <stdlib.h>
  18
  19 #define PROM_SIZE 0x10000       /* max */
  20
  21 static char *progname;
  22
  23 static void bail(const char *);
  24 int main(int, char **);
  25
  26 static void
  27 bail(const char *msg)
  28 {
  29         (void)fprintf(stderr, "%s: %s\n", progname, msg);
  30         exit(1);
  31 }
  32
  33 int
  34 main(int argc, char **argv)
  35 {
  36         char            w[PROM_SIZE];
  37         int             i, sum;
  38         int             romsize;
  39         unsigned short  ck16;
  40
  41         if ((progname = strrchr(argv[0], '/')) != NULL)
  42                 progname++;
  43         else
  44                 progname = argv[0];
  45
  46         if (argc > 1) {
  47                 if (sscanf(argv[1], "%d", &romsize) != 1)
  48                         bail("bad arg");
  49         } else {
  50                 bail("arg: romsize / bytes");
  51         }
  52
  53         (void)memset(w, 0x0, PROM_SIZE);
  54         i = fread(w, 1, PROM_SIZE, stdin);
  55
  56         (void)fprintf(stderr, "bios extension size: %d (0x%x), read %d bytes\n",
  57             romsize, romsize, i);
  58
  59         if (i > romsize)
  60                 bail("read longer than expected");
  61
  62         w[2] = romsize / 512;   /* BIOS extension size */
  63
  64         i = w[0x18] + (w[0x19] << 8);   /* if this is a PCI ROM, this is the
  65                                          * offset to the "PCI data structure" */
  66         if ((i < romsize - 0x18) && (w[i] == 'P') && (w[i + 1] == 'C')
  67             && (w[i + 2] == 'I') && (w[i + 3] == 'R')) {
  68                 fprintf(stderr, "PCI Data Structure found\n");
  69                 w[i + 0x10] = romsize / 512;    /* BIOS extension size again */
  70         }
  71         for (sum = 0, i = 0; i < romsize; i++)
  72                 sum += w[i];
  73
  74         w[5] = -sum;            /* left free for checksum adjustment */
  75
  76         /* calculate CRC as used by PROM programmers */
  77         for (ck16 = 0, i = 0; i < romsize; i++)
  78                 ck16 += (unsigned char) w[i];
  79         (void)fprintf(stderr, "ROM CRC: 0x%04x\n", ck16);
  80
  81         (void)fwrite(w, 1, romsize, stdout);
  82         return (0);
  83 }