70 lines
1.7 KiB
C
70 lines
1.7 KiB
C
/* $NetBSD: genprom.c,v 1.3 1997/03/22 09:07:19 thorpej Exp $ */
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/*
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* mainly from netbsd:sys/arch/i386/netboot/genprom.c
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*/
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/*
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* Read a binary image of a bios extension, generate the
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* appropriate block count and checksum and write them
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* into the rom image (replacing 2nd and 5th bytes)
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* The binary image should be sized before being filtered
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* through this routine.
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*/
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#include <stdio.h>
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#include <err.h>
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#include <string.h>
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#define PROM_SIZE 0x10000 /* max */
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int
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main(argc, argv)
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int argc;
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char **argv;
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{
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char w[PROM_SIZE];
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int i, sum;
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int romsize;
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unsigned short ck16;
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if (argc > 1) {
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if (sscanf(argv[1], "%d", &romsize) != 1) {
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errx(1, "bad arg");
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}
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} else {
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errx(1, "arg: romsize / bytes\n");
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}
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memset(w, 0x0, PROM_SIZE);
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i = fread(w, 1, PROM_SIZE, stdin);
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fprintf(stderr, "bios extension size: %d (0x%x), read %d bytes\n",
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romsize, romsize, i);
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if (i > romsize)
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errx(1, "read longer than expected");
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w[2] = romsize / 512; /* BIOS extension size */
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i = w[0x18] + (w[0x19] << 8); /* if this is a PCI ROM, this is the
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* offset to the "PCI data structure" */
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if ((i < romsize - 0x18) && (w[i] == 'P') && (w[i + 1] == 'C')
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&& (w[i + 2] == 'I') && (w[i + 3] == 'R')) {
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fprintf(stderr, "PCI Data Structure found\n");
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w[i + 0x10] = romsize / 512; /* BIOS extension size again */
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}
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for (sum = 0, i = 0; i < romsize; i++) {
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sum += w[i];
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}
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w[5] = -sum; /* left free for checksum adjustment */
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/* calculate CRC as used by PROM programmers */
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for (ck16 = 0, i = 0; i < romsize; i++)
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ck16 += (unsigned char) w[i];
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fprintf(stderr, "ROM CRC: 0x%04x\n", ck16);
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fwrite(w, 1, romsize, stdout);
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return (0);
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}
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