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 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 < 3) || (argc > 4)) 149 usage(); 150 if (argc > 3) { 151 if (!strcmp(argv[3], "CURRENT")) { 152 if (stat("/", &sb)) { 153 perror("/"); 154 die("Couldn't stat /"); 155 } 156 major_root = major(sb.st_dev); 157 minor_root = minor(sb.st_dev); 158 } else if (strcmp(argv[3], "FLOPPY")) { 159 if (stat(argv[3], &sb)) { 160 perror(argv[3]); 161 die("Couldn't stat root device."); 162 } 163 major_root = major(sb.st_rdev); 164 minor_root = minor(sb.st_rdev); 165 } else { 166 major_root = 0; 167 minor_root = 0; 168 } 169 } else { 170 major_root = DEFAULT_MAJOR_ROOT; 171 minor_root = DEFAULT_MINOR_ROOT; 172 } 173 fprintf(stderr, "Root device is (%d, %d)\n", major_root, minor_root); 174 175 /* Copy the setup code */ 176 file = fopen(argv[1], "r"); 177 if (!file) 178 die("Unable to open `%s': %m", argv[1]); 179 c = fread(buf, 1, sizeof(buf), file); 180 if (ferror(file)) 181 die("read-error on `setup'"); 182 if (c < 1024) 183 die("The setup must be at least 1024 bytes"); 184 if (buf[510] != 0x55 || buf[511] != 0xaa) 185 die("Boot block hasn't got boot flag (0xAA55)"); 186 fclose(file); 187 188 /* Pad unused space with zeros */ 189 setup_sectors = (c + 511) / 512; 190 if (setup_sectors < SETUP_SECT_MIN) 191 setup_sectors = SETUP_SECT_MIN; 192 i = setup_sectors*512; 193 memset(buf+c, 0, i-c); 194 195 /* Set the default root device */ 196 buf[508] = minor_root; 197 buf[509] = major_root; 198 199 fprintf(stderr, "Setup is %d bytes (padded to %d bytes).\n", c, i); 200 201 /* Open and stat the kernel file */ 202 fd = open(argv[2], O_RDONLY); 203 if (fd < 0) 204 die("Unable to open `%s': %m", argv[2]); 205 if (fstat(fd, &sb)) 206 die("Unable to stat `%s': %m", argv[2]); 207 sz = sb.st_size; 208 fprintf (stderr, "System is %d kB\n", (sz+1023)/1024); 209 kernel = mmap(NULL, sz, PROT_READ, MAP_SHARED, fd, 0); 210 if (kernel == MAP_FAILED) 211 die("Unable to mmap '%s': %m", argv[2]); 212 /* Number of 16-byte paragraphs, including space for a 4-byte CRC */ 213 sys_size = (sz + 15 + 4) / 16; 214 215 /* Patch the setup code with the appropriate size parameters */ 216 buf[0x1f1] = setup_sectors-1; 217 buf[0x1f4] = sys_size; 218 buf[0x1f5] = sys_size >> 8; 219 buf[0x1f6] = sys_size >> 16; 220 buf[0x1f7] = sys_size >> 24; 221 222 crc = partial_crc32(buf, i, crc); 223 if (fwrite(buf, 1, i, stdout) != i) 224 die("Writing setup failed"); 225 226 /* Copy the kernel code */ 227 crc = partial_crc32(kernel, sz, crc); 228 if (fwrite(kernel, 1, sz, stdout) != sz) 229 die("Writing kernel failed"); 230 231 /* Add padding leaving 4 bytes for the checksum */ 232 while (sz++ < (sys_size*16) - 4) { 233 crc = partial_crc32_one('\0', crc); 234 if (fwrite("\0", 1, 1, stdout) != 1) 235 die("Writing padding failed"); 236 } 237 238 /* Write the CRC */ 239 fprintf(stderr, "CRC %lx\n", crc); 240 if (fwrite(&crc, 1, 4, stdout) != 4) 241 die("Writing CRC failed"); 242 243 close(fd); 244 245 /* Everything is OK */ 246 return 0; 247 } 248