release/src-rt-6.x.4708/linux/linux-2.6.36/arch/mn10300/boot/tools/build.c

   1 /*
   2  *  Copyright (C) 1991, 1992  Linus Torvalds
   3  *  Copyright (C) 1997 Martin Mares
   4  */
   5
   6 /*
   7  * This file builds a disk-image from three different files:
   8  *
   9  * - bootsect: exactly 512 bytes of 8086 machine code, loads the rest
  10  * - setup: 8086 machine code, sets up system parm
  11  * - system: 80386 code for actual system
  12  *
  13  * It does some checking that all files are of the correct type, and
  14  * just writes the result to stdout, removing headers and padding to
  15  * the right amount. It also writes some system data to stderr.
  16  */
  17
  18 /*
  19  * Changes by tytso to allow root device specification
  20  * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
  21  * Cross compiling fixes by Gertjan van Wingerde, July 1996
  22  * Rewritten by Martin Mares, April 1997
  23  */
  24
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <stdlib.h>
  28 #include <stdarg.h>
  29 #include <sys/types.h>
  30 #include <sys/stat.h>
  31 #include <sys/sysmacros.h>
  32 #include <unistd.h>
  33 #include <fcntl.h>
  34 #include <asm/boot.h>
  35
  36 #define DEFAULT_MAJOR_ROOT 0
  37 #define DEFAULT_MINOR_ROOT 0
  38
  39 /* Minimal number of setup sectors (see also bootsect.S) */
  40 #define SETUP_SECTS 4
  41
  42 uint8_t buf[1024];
  43 int fd;
  44 int is_big_kernel;
  45
  46 __attribute__((noreturn))
  47 void die(const char *str, ...)
  48 {
  49         va_list args;
  50         va_start(args, str);
  51         vfprintf(stderr, str, args);
  52         fputc('\n', stderr);
  53         exit(1);
  54 }
  55
  56 void file_open(const char *name)
  57 {
  58         fd = open(name, O_RDONLY, 0);
  59         if (fd < 0)
  60                 die("Unable to open `%s': %m", name);
  61 }
  62
  63 __attribute__((noreturn))
  64 void usage(void)
  65 {
  66         die("Usage: build [-b] bootsect setup system [rootdev] [> image]");
  67 }
  68
  69 int main(int argc, char **argv)
  70 {
  71         unsigned int i, c, sz, setup_sectors;
  72         uint32_t sys_size;
  73         uint8_t major_root, minor_root;
  74         struct stat sb;
  75
  76         if (argc > 2 && !strcmp(argv[1], "-b")) {
  77                 is_big_kernel = 1;
  78                 argc--, argv++;
  79         }
  80         if ((argc < 4) || (argc > 5))
  81                 usage();
  82         if (argc > 4) {
  83                 if (!strcmp(argv[4], "CURRENT")) {
  84                         if (stat("/", &sb)) {
  85                                 perror("/");
  86                                 die("Couldn't stat /");
  87                         }
  88                         major_root = major(sb.st_dev);
  89                         minor_root = minor(sb.st_dev);
  90                 } else if (strcmp(argv[4], "FLOPPY")) {
  91                         if (stat(argv[4], &sb)) {
  92                                 perror(argv[4]);
  93                                 die("Couldn't stat root device.");
  94                         }
  95                         major_root = major(sb.st_rdev);
  96                         minor_root = minor(sb.st_rdev);
  97                 } else {
  98                         major_root = 0;
  99                         minor_root = 0;
 100                 }
 101         } else {
 102                 major_root = DEFAULT_MAJOR_ROOT;
 103                 minor_root = DEFAULT_MINOR_ROOT;
 104         }
 105         fprintf(stderr, "Root device is (%d, %d)\n", major_root, minor_root);
 106
 107         file_open(argv[1]);
 108         i = read(fd, buf, sizeof(buf));
 109         fprintf(stderr, "Boot sector %d bytes.\n", i);
 110         if (i != 512)
 111                 die("Boot block must be exactly 512 bytes");
 112         if (buf[510] != 0x55 || buf[511] != 0xaa)
 113                 die("Boot block hasn't got boot flag (0xAA55)");
 114         buf[508] = minor_root;
 115         buf[509] = major_root;
 116         if (write(1, buf, 512) != 512)
 117                 die("Write call failed");
 118         close(fd);
 119
 120         /* Copy the setup code */
 121         file_open(argv[2]);
 122         for (i = 0; (c = read(fd, buf, sizeof(buf))) > 0; i += c)
 123                 if (write(1, buf, c) != c)
 124                         die("Write call failed");
 125         if (c != 0)
 126                 die("read-error on `setup'");
 127         close(fd);
 128
 129         /* Pad unused space with zeros */
 130         setup_sectors = (i + 511) / 512;
 131         /* for compatibility with ancient versions of LILO. */
 132         if (setup_sectors < SETUP_SECTS)
 133                 setup_sectors = SETUP_SECTS;
 134         fprintf(stderr, "Setup is %d bytes.\n", i);
 135         memset(buf, 0, sizeof(buf));
 136         while (i < setup_sectors * 512) {
 137                 c = setup_sectors * 512 - i;
 138                 if (c > sizeof(buf))
 139                         c = sizeof(buf);
 140                 if (write(1, buf, c) != c)
 141                         die("Write call failed");
 142                 i += c;
 143         }
 144
 145         file_open(argv[3]);
 146         if (fstat(fd, &sb))
 147                 die("Unable to stat `%s': %m", argv[3]);
 148         sz = sb.st_size;
 149         fprintf(stderr, "System is %d kB\n", sz / 1024);
 150         sys_size = (sz + 15) / 16;
 151         /* 0x28000*16 = 2.5 MB, conservative estimate for the current maximum */
 152         if (sys_size > (is_big_kernel ? 0x28000 : DEF_SYSSIZE))
 153                 die("System is too big. Try using %smodules.",
 154                         is_big_kernel ? "" : "bzImage or ");
 155         if (sys_size > 0xffff)
 156                 fprintf(stderr,
 157                         "warning: kernel is too big for standalone boot "
 158                         "from floppy\n");
 159         while (sz > 0) {
 160                 int l, n;
 161
 162                 l = (sz > sizeof(buf)) ? sizeof(buf) : sz;
 163                 n = read(fd, buf, l);
 164                 if (n != l) {
 165                         if (n < 0)
 166                                 die("Error reading %s: %m", argv[3]);
 167                         else
 168                                 die("%s: Unexpected EOF", argv[3]);
 169                 }
 170                 if (write(1, buf, l) != l)
 171                         die("Write failed");
 172                 sz -= l;
 173         }
 174         close(fd);
 175
 176         /* Write sizes to the bootsector */
 177         if (lseek(1, 497, SEEK_SET) != 497)
 178                 die("Output: seek failed");
 179         buf[0] = setup_sectors;
 180         if (write(1, buf, 1) != 1)
 181                 die("Write of setup sector count failed");
 182         if (lseek(1, 500, SEEK_SET) != 500)
 183                 die("Output: seek failed");
 184         buf[0] = (sys_size & 0xff);
 185         buf[1] = ((sys_size >> 8) & 0xff);
 186         if (write(1, buf, 2) != 2)
 187                 die("Write of image length failed");
 188
 189         return 0;
 190 }