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 39typedef unsigned char u8; 40typedef unsigned short u16; 41typedef 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 */ 52u8 buf[SETUP_SECT_MAX*512]; 53 54#define PECOFF_RELOC_RESERVE 0x20 55 56#ifdef CONFIG_EFI_MIXED 57#define PECOFF_COMPAT_RESERVE 0x20 58#else 59#define PECOFF_COMPAT_RESERVE 0x0 60#endif 61 62static unsigned long efi32_stub_entry; 63static unsigned long efi64_stub_entry; 64static unsigned long efi_pe_entry; 65static unsigned long efi32_pe_entry; 66static unsigned long kernel_info; 67static unsigned long startup_64; 68static unsigned long _ehead; 69static unsigned long _end; 70 71/*----------------------------------------------------------------------*/ 72 73static const u32 crctab32[] = { 74 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 75 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 76 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 77 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 78 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 79 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 80 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 81 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 82 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 83 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, 84 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 85 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 86 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 87 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 88 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, 89 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, 90 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 91 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, 92 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 93 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 94 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 95 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 96 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, 97 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, 98 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 99 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 100 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 101 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 102 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, 103 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 104 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 105 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 106 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 107 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, 108 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 109 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 110 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 111 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 112 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, 113 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, 114 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 115 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, 116 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 117 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 118 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, 119 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 120 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 121 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, 122 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 123 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 124 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 125 0x2d02ef8d 126}; 127 128static u32 partial_crc32_one(u8 c, u32 crc) 129{ 130 return crctab32[(crc ^ c) & 0xff] ^ (crc >> 8); 131} 132 133static u32 partial_crc32(const u8 *s, int len, u32 crc) 134{ 135 while (len--) 136 crc = partial_crc32_one(*s++, crc); 137 return crc; 138} 139 140static void die(const char * str, ...) 141{ 142 va_list args; 143 va_start(args, str); 144 vfprintf(stderr, str, args); 145 va_end(args); 146 fputc('\n', stderr); 147 exit(1); 148} 149 150static void usage(void) 151{ 152 die("Usage: build setup system zoffset.h image"); 153} 154 155#ifdef CONFIG_EFI_STUB 156 157static void update_pecoff_section_header_fields(char *section_name, u32 vma, u32 size, u32 datasz, u32 offset) 158{ 159 unsigned int pe_header; 160 unsigned short num_sections; 161 u8 *section; 162 163 pe_header = get_unaligned_le32(&buf[0x3c]); 164 num_sections = get_unaligned_le16(&buf[pe_header + 6]); 165 166#ifdef CONFIG_X86_32 167 section = &buf[pe_header + 0xa8]; 168#else 169 section = &buf[pe_header + 0xb8]; 170#endif 171 172 while (num_sections > 0) { 173 if (strncmp((char*)section, section_name, 8) == 0) { 174 /* section header size field */ 175 put_unaligned_le32(size, section + 0x8); 176 177 /* section header vma field */ 178 put_unaligned_le32(vma, section + 0xc); 179 180 /* section header 'size of initialised data' field */ 181 put_unaligned_le32(datasz, section + 0x10); 182 183 /* section header 'file offset' field */ 184 put_unaligned_le32(offset, section + 0x14); 185 186 break; 187 } 188 section += 0x28; 189 num_sections--; 190 } 191} 192 193static void update_pecoff_section_header(char *section_name, u32 offset, u32 size) 194{ 195 update_pecoff_section_header_fields(section_name, offset, size, size, offset); 196} 197 198static void update_pecoff_setup_and_reloc(unsigned int size) 199{ 200 u32 setup_offset = 0x200; 201 u32 reloc_offset = size - PECOFF_RELOC_RESERVE - PECOFF_COMPAT_RESERVE; 202#ifdef CONFIG_EFI_MIXED 203 u32 compat_offset = reloc_offset + PECOFF_RELOC_RESERVE; 204#endif 205 u32 setup_size = reloc_offset - setup_offset; 206 207 update_pecoff_section_header(".setup", setup_offset, setup_size); 208 update_pecoff_section_header(".reloc", reloc_offset, PECOFF_RELOC_RESERVE); 209 210 /* 211 * Modify .reloc section contents with a single entry. The 212 * relocation is applied to offset 10 of the relocation section. 213 */ 214 put_unaligned_le32(reloc_offset + 10, &buf[reloc_offset]); 215 put_unaligned_le32(10, &buf[reloc_offset + 4]); 216 217#ifdef CONFIG_EFI_MIXED 218 update_pecoff_section_header(".compat", compat_offset, PECOFF_COMPAT_RESERVE); 219 220 /* 221 * Put the IA-32 machine type (0x14c) and the associated entry point 222 * address in the .compat section, so loaders can figure out which other 223 * execution modes this image supports. 224 */ 225 buf[compat_offset] = 0x1; 226 buf[compat_offset + 1] = 0x8; 227 put_unaligned_le16(0x14c, &buf[compat_offset + 2]); 228 put_unaligned_le32(efi32_pe_entry + size, &buf[compat_offset + 4]); 229#endif 230} 231 232static void update_pecoff_text(unsigned int text_start, unsigned int file_sz, 233 unsigned int init_sz) 234{ 235 unsigned int pe_header; 236 unsigned int text_sz = file_sz - text_start; 237 unsigned int bss_sz = init_sz - file_sz; 238 239 pe_header = get_unaligned_le32(&buf[0x3c]); 240 241 /* 242 * The PE/COFF loader may load the image at an address which is 243 * misaligned with respect to the kernel_alignment field in the setup 244 * header. 245 * 246 * In order to avoid relocating the kernel to correct the misalignment, 247 * add slack to allow the buffer to be aligned within the declared size 248 * of the image. 249 */ 250 bss_sz += CONFIG_PHYSICAL_ALIGN; 251 init_sz += CONFIG_PHYSICAL_ALIGN; 252 253 /* 254 * Size of code: Subtract the size of the first sector (512 bytes) 255 * which includes the header. 256 */ 257 put_unaligned_le32(file_sz - 512 + bss_sz, &buf[pe_header + 0x1c]); 258 259 /* Size of image */ 260 put_unaligned_le32(init_sz, &buf[pe_header + 0x50]); 261 262 /* 263 * Address of entry point for PE/COFF executable 264 */ 265 put_unaligned_le32(text_start + efi_pe_entry, &buf[pe_header + 0x28]); 266 267 update_pecoff_section_header_fields(".text", text_start, text_sz + bss_sz, 268 text_sz, text_start); 269} 270 271static int reserve_pecoff_reloc_section(int c) 272{ 273 /* Reserve 0x20 bytes for .reloc section */ 274 memset(buf+c, 0, PECOFF_RELOC_RESERVE); 275 return PECOFF_RELOC_RESERVE; 276} 277 278static void efi_stub_defaults(void) 279{ 280 /* Defaults for old kernel */ 281#ifdef CONFIG_X86_32 282 efi_pe_entry = 0x10; 283#else 284 efi_pe_entry = 0x210; 285 startup_64 = 0x200; 286#endif 287} 288 289static void efi_stub_entry_update(void) 290{ 291 unsigned long addr = efi32_stub_entry; 292 293#ifdef CONFIG_X86_64 294 /* Yes, this is really how we defined it :( */ 295 addr = efi64_stub_entry - 0x200; 296#endif 297 298#ifdef CONFIG_EFI_MIXED 299 if (efi32_stub_entry != addr) 300 die("32-bit and 64-bit EFI entry points do not match\n"); 301#endif 302 put_unaligned_le32(addr, &buf[0x264]); 303} 304 305#else 306 307static inline void update_pecoff_setup_and_reloc(unsigned int size) {} 308static inline void update_pecoff_text(unsigned int text_start, 309 unsigned int file_sz, 310 unsigned int init_sz) {} 311static inline void efi_stub_defaults(void) {} 312static inline void efi_stub_entry_update(void) {} 313 314static inline int reserve_pecoff_reloc_section(int c) 315{ 316 return 0; 317} 318#endif /* CONFIG_EFI_STUB */ 319 320static int reserve_pecoff_compat_section(int c) 321{ 322 /* Reserve 0x20 bytes for .compat section */ 323 memset(buf+c, 0, PECOFF_COMPAT_RESERVE); 324 return PECOFF_COMPAT_RESERVE; 325} 326 327/* 328 * Parse zoffset.h and find the entry points. We could just #include zoffset.h 329 * but that would mean tools/build would have to be rebuilt every time. It's 330 * not as if parsing it is hard... 331 */ 332#define PARSE_ZOFS(p, sym) do { \ 333 if (!strncmp(p, "#define ZO_" #sym " ", 11+sizeof(#sym))) \ 334 sym = strtoul(p + 11 + sizeof(#sym), NULL, 16); \ 335} while (0) 336 337static void parse_zoffset(char *fname) 338{ 339 FILE *file; 340 char *p; 341 int c; 342 343 file = fopen(fname, "r"); 344 if (!file) 345 die("Unable to open `%s': %m", fname); 346 c = fread(buf, 1, sizeof(buf) - 1, file); 347 if (ferror(file)) 348 die("read-error on `zoffset.h'"); 349 fclose(file); 350 buf[c] = 0; 351 352 p = (char *)buf; 353 354 while (p && *p) { 355 PARSE_ZOFS(p, efi32_stub_entry); 356 PARSE_ZOFS(p, efi64_stub_entry); 357 PARSE_ZOFS(p, efi_pe_entry); 358 PARSE_ZOFS(p, efi32_pe_entry); 359 PARSE_ZOFS(p, kernel_info); 360 PARSE_ZOFS(p, startup_64); 361 PARSE_ZOFS(p, _ehead); 362 PARSE_ZOFS(p, _end); 363 364 p = strchr(p, '\n'); 365 while (p && (*p == '\r' || *p == '\n')) 366 p++; 367 } 368} 369 370int main(int argc, char ** argv) 371{ 372 unsigned int i, sz, setup_sectors, init_sz; 373 int c; 374 u32 sys_size; 375 struct stat sb; 376 FILE *file, *dest; 377 int fd; 378 void *kernel; 379 u32 crc = 0xffffffffUL; 380 381 efi_stub_defaults(); 382 383 if (argc != 5) 384 usage(); 385 parse_zoffset(argv[3]); 386 387 dest = fopen(argv[4], "w"); 388 if (!dest) 389 die("Unable to write `%s': %m", argv[4]); 390 391 /* Copy the setup code */ 392 file = fopen(argv[1], "r"); 393 if (!file) 394 die("Unable to open `%s': %m", argv[1]); 395 c = fread(buf, 1, sizeof(buf), file); 396 if (ferror(file)) 397 die("read-error on `setup'"); 398 if (c < 1024) 399 die("The setup must be at least 1024 bytes"); 400 if (get_unaligned_le16(&buf[510]) != 0xAA55) 401 die("Boot block hasn't got boot flag (0xAA55)"); 402 fclose(file); 403 404 c += reserve_pecoff_compat_section(c); 405 c += reserve_pecoff_reloc_section(c); 406 407 /* Pad unused space with zeros */ 408 setup_sectors = (c + 511) / 512; 409 if (setup_sectors < SETUP_SECT_MIN) 410 setup_sectors = SETUP_SECT_MIN; 411 i = setup_sectors*512; 412 memset(buf+c, 0, i-c); 413 414 update_pecoff_setup_and_reloc(i); 415 416 /* Set the default root device */ 417 put_unaligned_le16(DEFAULT_ROOT_DEV, &buf[508]); 418 419 /* Open and stat the kernel file */ 420 fd = open(argv[2], O_RDONLY); 421 if (fd < 0) 422 die("Unable to open `%s': %m", argv[2]); 423 if (fstat(fd, &sb)) 424 die("Unable to stat `%s': %m", argv[2]); 425 sz = sb.st_size; 426 kernel = mmap(NULL, sz, PROT_READ, MAP_SHARED, fd, 0); 427 if (kernel == MAP_FAILED) 428 die("Unable to mmap '%s': %m", argv[2]); 429 /* Number of 16-byte paragraphs, including space for a 4-byte CRC */ 430 sys_size = (sz + 15 + 4) / 16; 431#ifdef CONFIG_EFI_STUB 432 /* 433 * COFF requires minimum 32-byte alignment of sections, and 434 * adding a signature is problematic without that alignment. 435 */ 436 sys_size = (sys_size + 1) & ~1; 437#endif 438 439 /* Patch the setup code with the appropriate size parameters */ 440 buf[0x1f1] = setup_sectors-1; 441 put_unaligned_le32(sys_size, &buf[0x1f4]); 442 443 init_sz = get_unaligned_le32(&buf[0x260]); 444#ifdef CONFIG_EFI_STUB 445 /* 446 * The decompression buffer will start at ImageBase. When relocating 447 * the compressed kernel to its end, we must ensure that the head 448 * section does not get overwritten. The head section occupies 449 * [i, i + _ehead), and the destination is [init_sz - _end, init_sz). 450 * 451 * At present these should never overlap, because 'i' is at most 32k 452 * because of SETUP_SECT_MAX, '_ehead' is less than 1k, and the 453 * calculation of INIT_SIZE in boot/header.S ensures that 454 * 'init_sz - _end' is at least 64k. 455 * 456 * For future-proofing, increase init_sz if necessary. 457 */ 458 459 if (init_sz - _end < i + _ehead) { 460 init_sz = (i + _ehead + _end + 4095) & ~4095; 461 put_unaligned_le32(init_sz, &buf[0x260]); 462 } 463#endif 464 update_pecoff_text(setup_sectors * 512, i + (sys_size * 16), init_sz); 465 466 efi_stub_entry_update(); 467 468 /* Update kernel_info offset. */ 469 put_unaligned_le32(kernel_info, &buf[0x268]); 470 471 crc = partial_crc32(buf, i, crc); 472 if (fwrite(buf, 1, i, dest) != i) 473 die("Writing setup failed"); 474 475 /* Copy the kernel code */ 476 crc = partial_crc32(kernel, sz, crc); 477 if (fwrite(kernel, 1, sz, dest) != sz) 478 die("Writing kernel failed"); 479 480 /* Add padding leaving 4 bytes for the checksum */ 481 while (sz++ < (sys_size*16) - 4) { 482 crc = partial_crc32_one('\0', crc); 483 if (fwrite("\0", 1, 1, dest) != 1) 484 die("Writing padding failed"); 485 } 486 487 /* Write the CRC */ 488 put_unaligned_le32(crc, buf); 489 if (fwrite(buf, 1, 4, dest) != 4) 490 die("Writing CRC failed"); 491 492 /* Catch any delayed write failures */ 493 if (fclose(dest)) 494 die("Writing image failed"); 495 496 close(fd); 497 498 /* Everything is OK */ 499 return 0; 500} 501