1 /* 2 * Copyright (C) 1991, 1992 Linus Torvalds 3 * Copyright (C) 1997 Martin Mares 4 * Copyright (C) 2007 H. Peter Anvin 5 */ 6 7 /* 8 * This file builds a disk-image from two different files: 9 * 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 * Substantially overhauled by H. Peter Anvin, April 2007 24 */ 25 26 #include <stdio.h> 27 #include <string.h> 28 #include <stdlib.h> 29 #include <stdarg.h> 30 #include <sys/types.h> 31 #include <sys/stat.h> 32 #include <sys/sysmacros.h> 33 #include <unistd.h> 34 #include <fcntl.h> 35 #include <sys/mman.h> 36 #include <asm/boot.h> 37 38 typedef unsigned char u8; 39 typedef unsigned short u16; 40 typedef unsigned long u32; 41 42 #define DEFAULT_MAJOR_ROOT 0 43 #define DEFAULT_MINOR_ROOT 0 44 45 /* Minimal number of setup sectors */ 46 #define SETUP_SECT_MIN 5 47 #define SETUP_SECT_MAX 64 48 49 /* This must be large enough to hold the entire setup */ 50 u8 buf[SETUP_SECT_MAX*512]; 51 int is_big_kernel; 52 53 /*----------------------------------------------------------------------*/ 54 55 static const u32 crctab32[] = { 56 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 57 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 58 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 59 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 60 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 61 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 62 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 63 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 64 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 65 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, 66 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 67 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 68 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 69 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 70 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, 71 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, 72 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 73 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, 74 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 75 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 76 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 77 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 78 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, 79 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, 80 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 81 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 82 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 83 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 84 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, 85 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 86 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 87 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 88 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 89 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, 90 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 91 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 92 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 93 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 94 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, 95 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, 96 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 97 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, 98 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 99 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 100 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, 101 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 102 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 103 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, 104 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 105 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 106 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 107 0x2d02ef8d 108 }; 109 110 static u32 partial_crc32_one(u8 c, u32 crc) 111 { 112 return crctab32[(crc ^ c) & 0xff] ^ (crc >> 8); 113 } 114 115 static u32 partial_crc32(const u8 *s, int len, u32 crc) 116 { 117 while (len--) 118 crc = partial_crc32_one(*s++, crc); 119 return crc; 120 } 121 122 static void die(const char * str, ...) 123 { 124 va_list args; 125 va_start(args, str); 126 vfprintf(stderr, str, args); 127 fputc('\n', stderr); 128 exit(1); 129 } 130 131 static void usage(void) 132 { 133 die("Usage: build [-b] setup system [rootdev] [> image]"); 134 } 135 136 int main(int argc, char ** argv) 137 { 138 unsigned int i, sz, setup_sectors; 139 int c; 140 u32 sys_size; 141 u8 major_root, minor_root; 142 struct stat sb; 143 FILE *file; 144 int fd; 145 void *kernel; 146 u32 crc = 0xffffffffUL; 147 148 if (argc > 2 && !strcmp(argv[1], "-b")) 149 { 150 is_big_kernel = 1; 151 argc--, argv++; 152 } 153 if ((argc < 3) || (argc > 4)) 154 usage(); 155 if (argc > 3) { 156 if (!strcmp(argv[3], "CURRENT")) { 157 if (stat("/", &sb)) { 158 perror("/"); 159 die("Couldn't stat /"); 160 } 161 major_root = major(sb.st_dev); 162 minor_root = minor(sb.st_dev); 163 } else if (strcmp(argv[3], "FLOPPY")) { 164 if (stat(argv[3], &sb)) { 165 perror(argv[3]); 166 die("Couldn't stat root device."); 167 } 168 major_root = major(sb.st_rdev); 169 minor_root = minor(sb.st_rdev); 170 } else { 171 major_root = 0; 172 minor_root = 0; 173 } 174 } else { 175 major_root = DEFAULT_MAJOR_ROOT; 176 minor_root = DEFAULT_MINOR_ROOT; 177 } 178 fprintf(stderr, "Root device is (%d, %d)\n", major_root, minor_root); 179 180 /* Copy the setup code */ 181 file = fopen(argv[1], "r"); 182 if (!file) 183 die("Unable to open `%s': %m", argv[1]); 184 c = fread(buf, 1, sizeof(buf), file); 185 if (ferror(file)) 186 die("read-error on `setup'"); 187 if (c < 1024) 188 die("The setup must be at least 1024 bytes"); 189 if (buf[510] != 0x55 || buf[511] != 0xaa) 190 die("Boot block hasn't got boot flag (0xAA55)"); 191 fclose(file); 192 193 /* Pad unused space with zeros */ 194 setup_sectors = (c + 511) / 512; 195 if (setup_sectors < SETUP_SECT_MIN) 196 setup_sectors = SETUP_SECT_MIN; 197 i = setup_sectors*512; 198 memset(buf+c, 0, i-c); 199 200 /* Set the default root device */ 201 buf[508] = minor_root; 202 buf[509] = major_root; 203 204 fprintf(stderr, "Setup is %d bytes (padded to %d bytes).\n", c, i); 205 206 /* Open and stat the kernel file */ 207 fd = open(argv[2], O_RDONLY); 208 if (fd < 0) 209 die("Unable to open `%s': %m", argv[2]); 210 if (fstat(fd, &sb)) 211 die("Unable to stat `%s': %m", argv[2]); 212 sz = sb.st_size; 213 fprintf (stderr, "System is %d kB\n", (sz+1023)/1024); 214 kernel = mmap(NULL, sz, PROT_READ, MAP_SHARED, fd, 0); 215 if (kernel == MAP_FAILED) 216 die("Unable to mmap '%s': %m", argv[2]); 217 /* Number of 16-byte paragraphs, including space for a 4-byte CRC */ 218 sys_size = (sz + 15 + 4) / 16; 219 if (!is_big_kernel && sys_size > DEF_SYSSIZE) 220 die("System is too big. Try using bzImage or modules."); 221 222 /* Patch the setup code with the appropriate size parameters */ 223 buf[0x1f1] = setup_sectors-1; 224 buf[0x1f4] = sys_size; 225 buf[0x1f5] = sys_size >> 8; 226 buf[0x1f6] = sys_size >> 16; 227 buf[0x1f7] = sys_size >> 24; 228 229 crc = partial_crc32(buf, i, crc); 230 if (fwrite(buf, 1, i, stdout) != i) 231 die("Writing setup failed"); 232 233 /* Copy the kernel code */ 234 crc = partial_crc32(kernel, sz, crc); 235 if (fwrite(kernel, 1, sz, stdout) != sz) 236 die("Writing kernel failed"); 237 238 /* Add padding leaving 4 bytes for the checksum */ 239 while (sz++ < (sys_size*16) - 4) { 240 crc = partial_crc32_one('\0', crc); 241 if (fwrite("\0", 1, 1, stdout) != 1) 242 die("Writing padding failed"); 243 } 244 245 /* Write the CRC */ 246 fprintf(stderr, "CRC %lx\n", crc); 247 if (fwrite(&crc, 1, 4, stdout) != 4) 248 die("Writing CRC failed"); 249 250 close(fd); 251 252 /* Everything is OK */ 253 return 0; 254 } 255