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 [> 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 struct stat sb; 142 FILE *file; 143 int fd; 144 void *kernel; 145 u32 crc = 0xffffffffUL; 146 147 if (argc != 3) 148 usage(); 149 150 /* Copy the setup code */ 151 file = fopen(argv[1], "r"); 152 if (!file) 153 die("Unable to open `%s': %m", argv[1]); 154 c = fread(buf, 1, sizeof(buf), file); 155 if (ferror(file)) 156 die("read-error on `setup'"); 157 if (c < 1024) 158 die("The setup must be at least 1024 bytes"); 159 if (buf[510] != 0x55 || buf[511] != 0xaa) 160 die("Boot block hasn't got boot flag (0xAA55)"); 161 fclose(file); 162 163 /* Pad unused space with zeros */ 164 setup_sectors = (c + 511) / 512; 165 if (setup_sectors < SETUP_SECT_MIN) 166 setup_sectors = SETUP_SECT_MIN; 167 i = setup_sectors*512; 168 memset(buf+c, 0, i-c); 169 170 /* Set the default root device */ 171 buf[508] = DEFAULT_MINOR_ROOT; 172 buf[509] = DEFAULT_MAJOR_ROOT; 173 174 fprintf(stderr, "Setup is %d bytes (padded to %d bytes).\n", c, i); 175 176 /* Open and stat the kernel file */ 177 fd = open(argv[2], O_RDONLY); 178 if (fd < 0) 179 die("Unable to open `%s': %m", argv[2]); 180 if (fstat(fd, &sb)) 181 die("Unable to stat `%s': %m", argv[2]); 182 sz = sb.st_size; 183 fprintf (stderr, "System is %d kB\n", (sz+1023)/1024); 184 kernel = mmap(NULL, sz, PROT_READ, MAP_SHARED, fd, 0); 185 if (kernel == MAP_FAILED) 186 die("Unable to mmap '%s': %m", argv[2]); 187 /* Number of 16-byte paragraphs, including space for a 4-byte CRC */ 188 sys_size = (sz + 15 + 4) / 16; 189 190 /* Patch the setup code with the appropriate size parameters */ 191 buf[0x1f1] = setup_sectors-1; 192 buf[0x1f4] = sys_size; 193 buf[0x1f5] = sys_size >> 8; 194 buf[0x1f6] = sys_size >> 16; 195 buf[0x1f7] = sys_size >> 24; 196 197 crc = partial_crc32(buf, i, crc); 198 if (fwrite(buf, 1, i, stdout) != i) 199 die("Writing setup failed"); 200 201 /* Copy the kernel code */ 202 crc = partial_crc32(kernel, sz, crc); 203 if (fwrite(kernel, 1, sz, stdout) != sz) 204 die("Writing kernel failed"); 205 206 /* Add padding leaving 4 bytes for the checksum */ 207 while (sz++ < (sys_size*16) - 4) { 208 crc = partial_crc32_one('\0', crc); 209 if (fwrite("\0", 1, 1, stdout) != 1) 210 die("Writing padding failed"); 211 } 212 213 /* Write the CRC */ 214 fprintf(stderr, "CRC %lx\n", crc); 215 if (fwrite(&crc, 1, 4, stdout) != 4) 216 die("Writing CRC failed"); 217 218 close(fd); 219 220 /* Everything is OK */ 221 return 0; 222 } 223