arch/x86/boot/tools/build.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Copyright (C) 1991, 1992  Linus Torvalds
   4  *  Copyright (C) 1997 Martin Mares
   5  *  Copyright (C) 2007 H. Peter Anvin
   6  */
   7
   8 /*
   9  * This file builds a disk-image from three different files:
  10  *
  11  * - setup: 8086 machine code, sets up system parm
  12  * - system: 80386 code for actual system
  13  * - zoffset.h: header with ZO_* defines
  14  *
  15  * It does some checking that all files are of the correct type, and writes
  16  * the result to the specified destination, removing headers and padding to
  17  * the right amount. It also writes some system data to stdout.
  18  */
  19
  20 /*
  21  * Changes by tytso to allow root device specification
  22  * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
  23  * Cross compiling fixes by Gertjan van Wingerde, July 1996
  24  * Rewritten by Martin Mares, April 1997
  25  * Substantially overhauled by H. Peter Anvin, April 2007
  26  */
  27
  28 #include <stdio.h>
  29 #include <string.h>
  30 #include <stdlib.h>
  31 #include <stdarg.h>
  32 #include <sys/types.h>
  33 #include <sys/stat.h>
  34 #include <unistd.h>
  35 #include <fcntl.h>
  36 #include <sys/mman.h>
  37 #include <tools/le_byteshift.h>
  38
  39 typedef unsigned char  u8;
  40 typedef unsigned short u16;
  41 typedef unsigned int   u32;
  42
  43 /* Minimal number of setup sectors */
  44 #define SETUP_SECT_MIN 5
  45 #define SETUP_SECT_MAX 64
  46
  47 /* This must be large enough to hold the entire setup */
  48 u8 buf[SETUP_SECT_MAX*512];
  49
  50 static unsigned long _edata;
  51
  52 /*----------------------------------------------------------------------*/
  53
  54 static const u32 crctab32[] = {
  55         0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419,
  56         0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,
  57         0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07,
  58         0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
  59         0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856,
  60         0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
  61         0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,
  62         0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
  63         0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3,
  64         0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a,
  65         0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599,
  66         0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
  67         0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190,
  68         0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,
  69         0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e,
  70         0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
  71         0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed,
  72         0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
  73         0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3,
  74         0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
  75         0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a,
  76         0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5,
  77         0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010,
  78         0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
  79         0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17,
  80         0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6,
  81         0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615,
  82         0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
  83         0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344,
  84         0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
  85         0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a,
  86         0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
  87         0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1,
  88         0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c,
  89         0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef,
  90         0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
  91         0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe,
  92         0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31,
  93         0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c,
  94         0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
  95         0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b,
  96         0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
  97         0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1,
  98         0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
  99         0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278,
 100         0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7,
 101         0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66,
 102         0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
 103         0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605,
 104         0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8,
 105         0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b,
 106         0x2d02ef8d
 107 };
 108
 109 static u32 partial_crc32_one(u8 c, u32 crc)
 110 {
 111         return crctab32[(crc ^ c) & 0xff] ^ (crc >> 8);
 112 }
 113
 114 static u32 partial_crc32(const u8 *s, int len, u32 crc)
 115 {
 116         while (len--)
 117                 crc = partial_crc32_one(*s++, crc);
 118         return crc;
 119 }
 120
 121 static void die(const char * str, ...)
 122 {
 123         va_list args;
 124         va_start(args, str);
 125         vfprintf(stderr, str, args);
 126         va_end(args);
 127         fputc('\n', stderr);
 128         exit(1);
 129 }
 130
 131 static void usage(void)
 132 {
 133         die("Usage: build setup system zoffset.h image");
 134 }
 135
 136 /*
 137  * Parse zoffset.h and find the entry points. We could just #include zoffset.h
 138  * but that would mean tools/build would have to be rebuilt every time. It's
 139  * not as if parsing it is hard...
 140  */
 141 #define PARSE_ZOFS(p, sym) do { \
 142         if (!strncmp(p, "#define ZO_" #sym " ", 11+sizeof(#sym)))       \
 143                 sym = strtoul(p + 11 + sizeof(#sym), NULL, 16);         \
 144 } while (0)
 145
 146 static void parse_zoffset(char *fname)
 147 {
 148         FILE *file;
 149         char *p;
 150         int c;
 151
 152         file = fopen(fname, "r");
 153         if (!file)
 154                 die("Unable to open `%s': %m", fname);
 155         c = fread(buf, 1, sizeof(buf) - 1, file);
 156         if (ferror(file))
 157                 die("read-error on `zoffset.h'");
 158         fclose(file);
 159         buf[c] = 0;
 160
 161         p = (char *)buf;
 162
 163         while (p && *p) {
 164                 PARSE_ZOFS(p, _edata);
 165
 166                 p = strchr(p, '\n');
 167                 while (p && (*p == '\r' || *p == '\n'))
 168                         p++;
 169         }
 170 }
 171
 172 int main(int argc, char ** argv)
 173 {
 174         unsigned int i, sz, setup_sectors;
 175         int c;
 176         struct stat sb;
 177         FILE *file, *dest;
 178         int fd;
 179         void *kernel;
 180         u32 crc = 0xffffffffUL;
 181
 182         if (argc != 5)
 183                 usage();
 184         parse_zoffset(argv[3]);
 185
 186         dest = fopen(argv[4], "w");
 187         if (!dest)
 188                 die("Unable to write `%s': %m", argv[4]);
 189
 190         /* Copy the setup code */
 191         file = fopen(argv[1], "r");
 192         if (!file)
 193                 die("Unable to open `%s': %m", argv[1]);
 194         c = fread(buf, 1, sizeof(buf), file);
 195         if (ferror(file))
 196                 die("read-error on `setup'");
 197         if (c < 1024)
 198                 die("The setup must be at least 1024 bytes");
 199         if (get_unaligned_le16(&buf[510]) != 0xAA55)
 200                 die("Boot block hasn't got boot flag (0xAA55)");
 201         fclose(file);
 202
 203         /* Pad unused space with zeros */
 204         setup_sectors = (c + 4095) / 4096;
 205         setup_sectors *= 8;
 206         if (setup_sectors < SETUP_SECT_MIN)
 207                 setup_sectors = SETUP_SECT_MIN;
 208         i = setup_sectors*512;
 209         memset(buf+c, 0, i-c);
 210
 211         /* Open and stat the kernel file */
 212         fd = open(argv[2], O_RDONLY);
 213         if (fd < 0)
 214                 die("Unable to open `%s': %m", argv[2]);
 215         if (fstat(fd, &sb))
 216                 die("Unable to stat `%s': %m", argv[2]);
 217         if (_edata != sb.st_size)
 218                 die("Unexpected file size `%s': %u != %u", argv[2], _edata,
 219                     sb.st_size);
 220         sz = _edata - 4;
 221         kernel = mmap(NULL, sz, PROT_READ, MAP_SHARED, fd, 0);
 222         if (kernel == MAP_FAILED)
 223                 die("Unable to mmap '%s': %m", argv[2]);
 224
 225         crc = partial_crc32(buf, i, crc);
 226         if (fwrite(buf, 1, i, dest) != i)
 227                 die("Writing setup failed");
 228
 229         /* Copy the kernel code */
 230         crc = partial_crc32(kernel, sz, crc);
 231         if (fwrite(kernel, 1, sz, dest) != sz)
 232                 die("Writing kernel failed");
 233
 234         /* Write the CRC */
 235         put_unaligned_le32(crc, buf);
 236         if (fwrite(buf, 1, 4, dest) != 4)
 237                 die("Writing CRC failed");
 238
 239         /* Catch any delayed write failures */
 240         if (fclose(dest))
 241                 die("Writing image failed");
 242
 243         close(fd);
 244
 245         /* Everything is OK */
 246         return 0;
 247 }