|  | /* | 
|  | *  Copyright (C) 1991, 1992  Linus Torvalds | 
|  | *  Copyright (C) 1997 Martin Mares | 
|  | *  Copyright (C) 2007 H. Peter Anvin | 
|  | */ | 
|  |  | 
|  | /* | 
|  | * This file builds a disk-image from two different files: | 
|  | * | 
|  | * - setup: 8086 machine code, sets up system parm | 
|  | * - system: 80386 code for actual system | 
|  | * | 
|  | * It does some checking that all files are of the correct type, and | 
|  | * just writes the result to stdout, removing headers and padding to | 
|  | * the right amount. It also writes some system data to stderr. | 
|  | */ | 
|  |  | 
|  | /* | 
|  | * Changes by tytso to allow root device specification | 
|  | * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996 | 
|  | * Cross compiling fixes by Gertjan van Wingerde, July 1996 | 
|  | * Rewritten by Martin Mares, April 1997 | 
|  | * Substantially overhauled by H. Peter Anvin, April 2007 | 
|  | */ | 
|  |  | 
|  | #include <stdio.h> | 
|  | #include <string.h> | 
|  | #include <stdlib.h> | 
|  | #include <stdarg.h> | 
|  | #include <sys/types.h> | 
|  | #include <sys/stat.h> | 
|  | #include <sys/sysmacros.h> | 
|  | #include <unistd.h> | 
|  | #include <fcntl.h> | 
|  | #include <sys/mman.h> | 
|  | #include <asm/boot.h> | 
|  |  | 
|  | typedef unsigned char  u8; | 
|  | typedef unsigned short u16; | 
|  | typedef unsigned long  u32; | 
|  |  | 
|  | #define DEFAULT_MAJOR_ROOT 0 | 
|  | #define DEFAULT_MINOR_ROOT 0 | 
|  |  | 
|  | /* Minimal number of setup sectors */ | 
|  | #define SETUP_SECT_MIN 5 | 
|  | #define SETUP_SECT_MAX 64 | 
|  |  | 
|  | /* This must be large enough to hold the entire setup */ | 
|  | u8 buf[SETUP_SECT_MAX*512]; | 
|  | int is_big_kernel; | 
|  |  | 
|  | /*----------------------------------------------------------------------*/ | 
|  |  | 
|  | static const u32 crctab32[] = { | 
|  | 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, | 
|  | 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, | 
|  | 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, | 
|  | 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, | 
|  | 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, | 
|  | 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, | 
|  | 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, | 
|  | 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, | 
|  | 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, | 
|  | 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, | 
|  | 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, | 
|  | 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, | 
|  | 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, | 
|  | 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, | 
|  | 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, | 
|  | 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, | 
|  | 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, | 
|  | 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, | 
|  | 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, | 
|  | 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, | 
|  | 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, | 
|  | 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, | 
|  | 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, | 
|  | 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, | 
|  | 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, | 
|  | 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, | 
|  | 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, | 
|  | 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, | 
|  | 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, | 
|  | 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, | 
|  | 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, | 
|  | 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, | 
|  | 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, | 
|  | 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, | 
|  | 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, | 
|  | 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, | 
|  | 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, | 
|  | 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, | 
|  | 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, | 
|  | 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, | 
|  | 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, | 
|  | 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, | 
|  | 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, | 
|  | 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, | 
|  | 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, | 
|  | 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, | 
|  | 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, | 
|  | 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, | 
|  | 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, | 
|  | 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, | 
|  | 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, | 
|  | 0x2d02ef8d | 
|  | }; | 
|  |  | 
|  | static u32 partial_crc32_one(u8 c, u32 crc) | 
|  | { | 
|  | return crctab32[(crc ^ c) & 0xff] ^ (crc >> 8); | 
|  | } | 
|  |  | 
|  | static u32 partial_crc32(const u8 *s, int len, u32 crc) | 
|  | { | 
|  | while (len--) | 
|  | crc = partial_crc32_one(*s++, crc); | 
|  | return crc; | 
|  | } | 
|  |  | 
|  | static void die(const char * str, ...) | 
|  | { | 
|  | va_list args; | 
|  | va_start(args, str); | 
|  | vfprintf(stderr, str, args); | 
|  | fputc('\n', stderr); | 
|  | exit(1); | 
|  | } | 
|  |  | 
|  | static void usage(void) | 
|  | { | 
|  | die("Usage: build [-b] setup system [rootdev] [> image]"); | 
|  | } | 
|  |  | 
|  | int main(int argc, char ** argv) | 
|  | { | 
|  | unsigned int i, sz, setup_sectors; | 
|  | int c; | 
|  | u32 sys_size; | 
|  | u8 major_root, minor_root; | 
|  | struct stat sb; | 
|  | FILE *file; | 
|  | int fd; | 
|  | void *kernel; | 
|  | u32 crc = 0xffffffffUL; | 
|  |  | 
|  | if (argc > 2 && !strcmp(argv[1], "-b")) | 
|  | { | 
|  | is_big_kernel = 1; | 
|  | argc--, argv++; | 
|  | } | 
|  | if ((argc < 3) || (argc > 4)) | 
|  | usage(); | 
|  | if (argc > 3) { | 
|  | if (!strcmp(argv[3], "CURRENT")) { | 
|  | if (stat("/", &sb)) { | 
|  | perror("/"); | 
|  | die("Couldn't stat /"); | 
|  | } | 
|  | major_root = major(sb.st_dev); | 
|  | minor_root = minor(sb.st_dev); | 
|  | } else if (strcmp(argv[3], "FLOPPY")) { | 
|  | if (stat(argv[3], &sb)) { | 
|  | perror(argv[3]); | 
|  | die("Couldn't stat root device."); | 
|  | } | 
|  | major_root = major(sb.st_rdev); | 
|  | minor_root = minor(sb.st_rdev); | 
|  | } else { | 
|  | major_root = 0; | 
|  | minor_root = 0; | 
|  | } | 
|  | } else { | 
|  | major_root = DEFAULT_MAJOR_ROOT; | 
|  | minor_root = DEFAULT_MINOR_ROOT; | 
|  | } | 
|  | fprintf(stderr, "Root device is (%d, %d)\n", major_root, minor_root); | 
|  |  | 
|  | /* Copy the setup code */ | 
|  | file = fopen(argv[1], "r"); | 
|  | if (!file) | 
|  | die("Unable to open `%s': %m", argv[1]); | 
|  | c = fread(buf, 1, sizeof(buf), file); | 
|  | if (ferror(file)) | 
|  | die("read-error on `setup'"); | 
|  | if (c < 1024) | 
|  | die("The setup must be at least 1024 bytes"); | 
|  | if (buf[510] != 0x55 || buf[511] != 0xaa) | 
|  | die("Boot block hasn't got boot flag (0xAA55)"); | 
|  | fclose(file); | 
|  |  | 
|  | /* Pad unused space with zeros */ | 
|  | setup_sectors = (c + 511) / 512; | 
|  | if (setup_sectors < SETUP_SECT_MIN) | 
|  | setup_sectors = SETUP_SECT_MIN; | 
|  | i = setup_sectors*512; | 
|  | memset(buf+c, 0, i-c); | 
|  |  | 
|  | /* Set the default root device */ | 
|  | buf[508] = minor_root; | 
|  | buf[509] = major_root; | 
|  |  | 
|  | fprintf(stderr, "Setup is %d bytes (padded to %d bytes).\n", c, i); | 
|  |  | 
|  | /* Open and stat the kernel file */ | 
|  | fd = open(argv[2], O_RDONLY); | 
|  | if (fd < 0) | 
|  | die("Unable to open `%s': %m", argv[2]); | 
|  | if (fstat(fd, &sb)) | 
|  | die("Unable to stat `%s': %m", argv[2]); | 
|  | sz = sb.st_size; | 
|  | fprintf (stderr, "System is %d kB\n", (sz+1023)/1024); | 
|  | kernel = mmap(NULL, sz, PROT_READ, MAP_SHARED, fd, 0); | 
|  | if (kernel == MAP_FAILED) | 
|  | die("Unable to mmap '%s': %m", argv[2]); | 
|  | /* Number of 16-byte paragraphs, including space for a 4-byte CRC */ | 
|  | sys_size = (sz + 15 + 4) / 16; | 
|  | if (!is_big_kernel && sys_size > DEF_SYSSIZE) | 
|  | die("System is too big. Try using bzImage or modules."); | 
|  |  | 
|  | /* Patch the setup code with the appropriate size parameters */ | 
|  | buf[0x1f1] = setup_sectors-1; | 
|  | buf[0x1f4] = sys_size; | 
|  | buf[0x1f5] = sys_size >> 8; | 
|  | buf[0x1f6] = sys_size >> 16; | 
|  | buf[0x1f7] = sys_size >> 24; | 
|  |  | 
|  | crc = partial_crc32(buf, i, crc); | 
|  | if (fwrite(buf, 1, i, stdout) != i) | 
|  | die("Writing setup failed"); | 
|  |  | 
|  | /* Copy the kernel code */ | 
|  | crc = partial_crc32(kernel, sz, crc); | 
|  | if (fwrite(kernel, 1, sz, stdout) != sz) | 
|  | die("Writing kernel failed"); | 
|  |  | 
|  | /* Add padding leaving 4 bytes for the checksum */ | 
|  | while (sz++ < (sys_size*16) - 4) { | 
|  | crc = partial_crc32_one('\0', crc); | 
|  | if (fwrite("\0", 1, 1, stdout) != 1) | 
|  | die("Writing padding failed"); | 
|  | } | 
|  |  | 
|  | /* Write the CRC */ | 
|  | fprintf(stderr, "CRC %lx\n", crc); | 
|  | if (fwrite(&crc, 1, 4, stdout) != 4) | 
|  | die("Writing CRC failed"); | 
|  |  | 
|  | close(fd); | 
|  |  | 
|  | /* Everything is OK */ | 
|  | return 0; | 
|  | } |