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 #define DEFAULT_MAJOR_ROOT 0 44 #define DEFAULT_MINOR_ROOT 0 45 #define DEFAULT_ROOT_DEV (DEFAULT_MAJOR_ROOT << 8 | DEFAULT_MINOR_ROOT) 46 47 /* Minimal number of setup sectors */ 48 #define SETUP_SECT_MIN 5 49 #define SETUP_SECT_MAX 64 50 51 /* This must be large enough to hold the entire setup */ 52 u8 buf[SETUP_SECT_MAX*512]; 53 54 #define PECOFF_RELOC_RESERVE 0x20 55 56 unsigned long efi32_stub_entry; 57 unsigned long efi64_stub_entry; 58 unsigned long efi_pe_entry; 59 unsigned long startup_64; 60 61 /*----------------------------------------------------------------------*/ 62 63 static const u32 crctab32[] = { 64 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 65 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 66 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 67 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 68 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 69 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 70 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 71 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 72 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 73 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, 74 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 75 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 76 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 77 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 78 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, 79 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, 80 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 81 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, 82 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 83 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 84 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 85 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 86 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, 87 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, 88 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 89 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 90 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 91 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 92 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, 93 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 94 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 95 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 96 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 97 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, 98 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 99 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 100 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 101 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 102 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, 103 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, 104 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 105 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, 106 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 107 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 108 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, 109 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 110 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 111 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, 112 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 113 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 114 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 115 0x2d02ef8d 116 }; 117 118 static u32 partial_crc32_one(u8 c, u32 crc) 119 { 120 return crctab32[(crc ^ c) & 0xff] ^ (crc >> 8); 121 } 122 123 static u32 partial_crc32(const u8 *s, int len, u32 crc) 124 { 125 while (len--) 126 crc = partial_crc32_one(*s++, crc); 127 return crc; 128 } 129 130 static void die(const char * str, ...) 131 { 132 va_list args; 133 va_start(args, str); 134 vfprintf(stderr, str, args); 135 fputc('\n', stderr); 136 exit(1); 137 } 138 139 static void usage(void) 140 { 141 die("Usage: build setup system zoffset.h image"); 142 } 143 144 #ifdef CONFIG_EFI_STUB 145 146 static void update_pecoff_section_header_fields(char *section_name, u32 vma, u32 size, u32 datasz, u32 offset) 147 { 148 unsigned int pe_header; 149 unsigned short num_sections; 150 u8 *section; 151 152 pe_header = get_unaligned_le32(&buf[0x3c]); 153 num_sections = get_unaligned_le16(&buf[pe_header + 6]); 154 155 #ifdef CONFIG_X86_32 156 section = &buf[pe_header + 0xa8]; 157 #else 158 section = &buf[pe_header + 0xb8]; 159 #endif 160 161 while (num_sections > 0) { 162 if (strncmp((char*)section, section_name, 8) == 0) { 163 /* section header size field */ 164 put_unaligned_le32(size, section + 0x8); 165 166 /* section header vma field */ 167 put_unaligned_le32(vma, section + 0xc); 168 169 /* section header 'size of initialised data' field */ 170 put_unaligned_le32(datasz, section + 0x10); 171 172 /* section header 'file offset' field */ 173 put_unaligned_le32(offset, section + 0x14); 174 175 break; 176 } 177 section += 0x28; 178 num_sections--; 179 } 180 } 181 182 static void update_pecoff_section_header(char *section_name, u32 offset, u32 size) 183 { 184 update_pecoff_section_header_fields(section_name, offset, size, size, offset); 185 } 186 187 static void update_pecoff_setup_and_reloc(unsigned int size) 188 { 189 u32 setup_offset = 0x200; 190 u32 reloc_offset = size - PECOFF_RELOC_RESERVE; 191 u32 setup_size = reloc_offset - setup_offset; 192 193 update_pecoff_section_header(".setup", setup_offset, setup_size); 194 update_pecoff_section_header(".reloc", reloc_offset, PECOFF_RELOC_RESERVE); 195 196 /* 197 * Modify .reloc section contents with a single entry. The 198 * relocation is applied to offset 10 of the relocation section. 199 */ 200 put_unaligned_le32(reloc_offset + 10, &buf[reloc_offset]); 201 put_unaligned_le32(10, &buf[reloc_offset + 4]); 202 } 203 204 static void update_pecoff_text(unsigned int text_start, unsigned int file_sz) 205 { 206 unsigned int pe_header; 207 unsigned int text_sz = file_sz - text_start; 208 209 pe_header = get_unaligned_le32(&buf[0x3c]); 210 211 /* 212 * Size of code: Subtract the size of the first sector (512 bytes) 213 * which includes the header. 214 */ 215 put_unaligned_le32(file_sz - 512, &buf[pe_header + 0x1c]); 216 217 /* 218 * Address of entry point for PE/COFF executable 219 */ 220 put_unaligned_le32(text_start + efi_pe_entry, &buf[pe_header + 0x28]); 221 222 update_pecoff_section_header(".text", text_start, text_sz); 223 } 224 225 static void update_pecoff_bss(unsigned int file_sz, unsigned int init_sz) 226 { 227 unsigned int pe_header; 228 unsigned int bss_sz = init_sz - file_sz; 229 230 pe_header = get_unaligned_le32(&buf[0x3c]); 231 232 /* Size of uninitialized data */ 233 put_unaligned_le32(bss_sz, &buf[pe_header + 0x24]); 234 235 /* Size of image */ 236 put_unaligned_le32(init_sz, &buf[pe_header + 0x50]); 237 238 update_pecoff_section_header_fields(".bss", file_sz, bss_sz, 0, 0); 239 } 240 241 static int reserve_pecoff_reloc_section(int c) 242 { 243 /* Reserve 0x20 bytes for .reloc section */ 244 memset(buf+c, 0, PECOFF_RELOC_RESERVE); 245 return PECOFF_RELOC_RESERVE; 246 } 247 248 static void efi_stub_defaults(void) 249 { 250 /* Defaults for old kernel */ 251 #ifdef CONFIG_X86_32 252 efi_pe_entry = 0x10; 253 #else 254 efi_pe_entry = 0x210; 255 startup_64 = 0x200; 256 #endif 257 } 258 259 static void efi_stub_entry_update(void) 260 { 261 unsigned long addr = efi32_stub_entry; 262 263 #ifdef CONFIG_X86_64 264 /* Yes, this is really how we defined it :( */ 265 addr = efi64_stub_entry - 0x200; 266 #endif 267 268 #ifdef CONFIG_EFI_MIXED 269 if (efi32_stub_entry != addr) 270 die("32-bit and 64-bit EFI entry points do not match\n"); 271 #endif 272 put_unaligned_le32(addr, &buf[0x264]); 273 } 274 275 #else 276 277 static inline void update_pecoff_setup_and_reloc(unsigned int size) {} 278 static inline void update_pecoff_text(unsigned int text_start, 279 unsigned int file_sz) {} 280 static inline void update_pecoff_bss(unsigned int file_sz, 281 unsigned int init_sz) {} 282 static inline void efi_stub_defaults(void) {} 283 static inline void efi_stub_entry_update(void) {} 284 285 static inline int reserve_pecoff_reloc_section(int c) 286 { 287 return 0; 288 } 289 #endif /* CONFIG_EFI_STUB */ 290 291 292 /* 293 * Parse zoffset.h and find the entry points. We could just #include zoffset.h 294 * but that would mean tools/build would have to be rebuilt every time. It's 295 * not as if parsing it is hard... 296 */ 297 #define PARSE_ZOFS(p, sym) do { \ 298 if (!strncmp(p, "#define ZO_" #sym " ", 11+sizeof(#sym))) \ 299 sym = strtoul(p + 11 + sizeof(#sym), NULL, 16); \ 300 } while (0) 301 302 static void parse_zoffset(char *fname) 303 { 304 FILE *file; 305 char *p; 306 int c; 307 308 file = fopen(fname, "r"); 309 if (!file) 310 die("Unable to open `%s': %m", fname); 311 c = fread(buf, 1, sizeof(buf) - 1, file); 312 if (ferror(file)) 313 die("read-error on `zoffset.h'"); 314 fclose(file); 315 buf[c] = 0; 316 317 p = (char *)buf; 318 319 while (p && *p) { 320 PARSE_ZOFS(p, efi32_stub_entry); 321 PARSE_ZOFS(p, efi64_stub_entry); 322 PARSE_ZOFS(p, efi_pe_entry); 323 PARSE_ZOFS(p, startup_64); 324 325 p = strchr(p, '\n'); 326 while (p && (*p == '\r' || *p == '\n')) 327 p++; 328 } 329 } 330 331 int main(int argc, char ** argv) 332 { 333 unsigned int i, sz, setup_sectors, init_sz; 334 int c; 335 u32 sys_size; 336 struct stat sb; 337 FILE *file, *dest; 338 int fd; 339 void *kernel; 340 u32 crc = 0xffffffffUL; 341 342 efi_stub_defaults(); 343 344 if (argc != 5) 345 usage(); 346 parse_zoffset(argv[3]); 347 348 dest = fopen(argv[4], "w"); 349 if (!dest) 350 die("Unable to write `%s': %m", argv[4]); 351 352 /* Copy the setup code */ 353 file = fopen(argv[1], "r"); 354 if (!file) 355 die("Unable to open `%s': %m", argv[1]); 356 c = fread(buf, 1, sizeof(buf), file); 357 if (ferror(file)) 358 die("read-error on `setup'"); 359 if (c < 1024) 360 die("The setup must be at least 1024 bytes"); 361 if (get_unaligned_le16(&buf[510]) != 0xAA55) 362 die("Boot block hasn't got boot flag (0xAA55)"); 363 fclose(file); 364 365 c += reserve_pecoff_reloc_section(c); 366 367 /* Pad unused space with zeros */ 368 setup_sectors = (c + 511) / 512; 369 if (setup_sectors < SETUP_SECT_MIN) 370 setup_sectors = SETUP_SECT_MIN; 371 i = setup_sectors*512; 372 memset(buf+c, 0, i-c); 373 374 update_pecoff_setup_and_reloc(i); 375 376 /* Set the default root device */ 377 put_unaligned_le16(DEFAULT_ROOT_DEV, &buf[508]); 378 379 printf("Setup is %d bytes (padded to %d bytes).\n", c, i); 380 381 /* Open and stat the kernel file */ 382 fd = open(argv[2], O_RDONLY); 383 if (fd < 0) 384 die("Unable to open `%s': %m", argv[2]); 385 if (fstat(fd, &sb)) 386 die("Unable to stat `%s': %m", argv[2]); 387 sz = sb.st_size; 388 printf("System is %d kB\n", (sz+1023)/1024); 389 kernel = mmap(NULL, sz, PROT_READ, MAP_SHARED, fd, 0); 390 if (kernel == MAP_FAILED) 391 die("Unable to mmap '%s': %m", argv[2]); 392 /* Number of 16-byte paragraphs, including space for a 4-byte CRC */ 393 sys_size = (sz + 15 + 4) / 16; 394 395 /* Patch the setup code with the appropriate size parameters */ 396 buf[0x1f1] = setup_sectors-1; 397 put_unaligned_le32(sys_size, &buf[0x1f4]); 398 399 update_pecoff_text(setup_sectors * 512, i + (sys_size * 16)); 400 init_sz = get_unaligned_le32(&buf[0x260]); 401 update_pecoff_bss(i + (sys_size * 16), init_sz); 402 403 efi_stub_entry_update(); 404 405 crc = partial_crc32(buf, i, crc); 406 if (fwrite(buf, 1, i, dest) != i) 407 die("Writing setup failed"); 408 409 /* Copy the kernel code */ 410 crc = partial_crc32(kernel, sz, crc); 411 if (fwrite(kernel, 1, sz, dest) != sz) 412 die("Writing kernel failed"); 413 414 /* Add padding leaving 4 bytes for the checksum */ 415 while (sz++ < (sys_size*16) - 4) { 416 crc = partial_crc32_one('\0', crc); 417 if (fwrite("\0", 1, 1, dest) != 1) 418 die("Writing padding failed"); 419 } 420 421 /* Write the CRC */ 422 printf("CRC %x\n", crc); 423 put_unaligned_le32(crc, buf); 424 if (fwrite(buf, 1, 4, dest) != 4) 425 die("Writing CRC failed"); 426 427 /* Catch any delayed write failures */ 428 if (fclose(dest)) 429 die("Writing image failed"); 430 431 close(fd); 432 433 /* Everything is OK */ 434 return 0; 435 } 436