arch/m68k-amiga/boot/floppy/install.c

   1 /*
   2     Copyright © 1995-2010, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include <errno.h>
   7 #include <string.h>
   8 #include <stdint.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <unistd.h>
  12 #include <fcntl.h>
  13
  14 #include <sys/stat.h>
  15
  16 typedef uint8_t  UBYTE;
  17 typedef uint32_t ULONG;
  18
  19 struct BootBlock {
  20     UBYTE       DiskType[4];
  21     ULONG       Chksum;
  22     ULONG       RootBlock;
  23     UBYTE       BootBlockCode[0];
  24 } __attribute__((packed));
  25
  26 const UBYTE m68k_boot[] = {
  27     0x43, 0xfa, 0x00, 0x18,   0x4e, 0xae, 0xff, 0xa0,
  28     0x4a, 0x80, 0x67, 0x0a,   0x20, 0x40, 0x20, 0x68,
  29     0x00, 0x16, 0x70, 0x00,   0x4e, 0x75, 0x70, 0xff,
  30     0x60, 0xfa, 0x64, 0x6f,   0x73, 0x2e, 0x6c, 0x69,
  31     0x62, 0x72, 0x61, 0x72,   0x79, 0x00 };
  32
  33 #define BOOTBLOCKSIZE   1024
  34
  35 /* Adapted from rom/boot/strap.c */
  36 static void BootBlockChecksum(UBYTE *bootblock, size_t size)
  37 {
  38        ULONG crc = 0;
  39        int i;
  40
  41        memset(bootblock+4, 0, 4);
  42
  43        for (i = 0; i < size; i += 4) {
  44            ULONG v = (bootblock[i] << 24) | (bootblock[i + 1] << 16) |
  45 (bootblock[i + 2] << 8) | bootblock[i + 3];
  46            if (crc + v < crc)
  47                crc++;
  48            crc += v;
  49        }
  50        crc ^= 0xffffffff;
  51
  52        bootblock[4+0] = (crc >> 24) & 0xff;
  53        bootblock[4+1] = (crc >> 16) & 0xff;
  54        bootblock[4+2] = (crc >>  8) & 0xff;
  55        bootblock[4+3] = (crc >>  0) & 0xff;
  56 }
  57
  58
  59 int main(int argc, char **argv)
  60 {
  61     int fd, err, i;
  62     const char *image = argv[1];
  63     UBYTE buff[BOOTBLOCKSIZE];
  64     struct BootBlock *bootblock = (void *)&buff[0];
  65     ULONG csum, psum;
  66
  67     fd = open(image, O_RDWR);
  68     if (fd < 0) {
  69         perror(image);
  70         return EXIT_FAILURE;
  71     }
  72
  73     err = read(fd, buff, sizeof(buff));
  74     if (err < 0) {
  75         perror(image);
  76         close(fd);
  77     }
  78
  79     lseek(fd, 0, SEEK_SET);
  80
  81     if (memcmp(bootblock->DiskType, "DOS", 3) != 0) {
  82         fprintf(stderr, "%s: Not a DOS (OFS or FFS) disk\n", image);
  83         close(fd);
  84         return EXIT_FAILURE;
  85     }
  86
  87     memset(bootblock->BootBlockCode, 0, sizeof(buff)-sizeof(struct BootBlock));
  88
  89     memcpy(bootblock->BootBlockCode, m68k_boot, sizeof(m68k_boot));
  90
  91     BootBlockChecksum(buff, sizeof(buff));
  92
  93     err = write(fd, buff, 1024);
  94     if (err < 0) {
  95         perror(image);
  96         close(fd);
  97         return EXIT_FAILURE;
  98     }
  99
 100     close(fd);
 101     return EXIT_SUCCESS;
 102 }