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 va_end(args); 136 fputc('\n', stderr); 137 exit(1); 138 } 139 140 static void usage(void) 141 { 142 die("Usage: build setup system zoffset.h image"); 143 } 144 145 #ifdef CONFIG_EFI_STUB 146 147 static void update_pecoff_section_header_fields(char *section_name, u32 vma, u32 size, u32 datasz, u32 offset) 148 { 149 unsigned int pe_header; 150 unsigned short num_sections; 151 u8 *section; 152 153 pe_header = get_unaligned_le32(&buf[0x3c]); 154 num_sections = get_unaligned_le16(&buf[pe_header + 6]); 155 156 #ifdef CONFIG_X86_32 157 section = &buf[pe_header + 0xa8]; 158 #else 159 section = &buf[pe_header + 0xb8]; 160 #endif 161 162 while (num_sections > 0) { 163 if (strncmp((char*)section, section_name, 8) == 0) { 164 /* section header size field */ 165 put_unaligned_le32(size, section + 0x8); 166 167 /* section header vma field */ 168 put_unaligned_le32(vma, section + 0xc); 169 170 /* section header 'size of initialised data' field */ 171 put_unaligned_le32(datasz, section + 0x10); 172 173 /* section header 'file offset' field */ 174 put_unaligned_le32(offset, section + 0x14); 175 176 break; 177 } 178 section += 0x28; 179 num_sections--; 180 } 181 } 182 183 static void update_pecoff_section_header(char *section_name, u32 offset, u32 size) 184 { 185 update_pecoff_section_header_fields(section_name, offset, size, size, offset); 186 } 187 188 static void update_pecoff_setup_and_reloc(unsigned int size) 189 { 190 u32 setup_offset = 0x200; 191 u32 reloc_offset = size - PECOFF_RELOC_RESERVE; 192 u32 setup_size = reloc_offset - setup_offset; 193 194 update_pecoff_section_header(".setup", setup_offset, setup_size); 195 update_pecoff_section_header(".reloc", reloc_offset, PECOFF_RELOC_RESERVE); 196 197 /* 198 * Modify .reloc section contents with a single entry. The 199 * relocation is applied to offset 10 of the relocation section. 200 */ 201 put_unaligned_le32(reloc_offset + 10, &buf[reloc_offset]); 202 put_unaligned_le32(10, &buf[reloc_offset + 4]); 203 } 204 205 static void update_pecoff_text(unsigned int text_start, unsigned int file_sz) 206 { 207 unsigned int pe_header; 208 unsigned int text_sz = file_sz - text_start; 209 210 pe_header = get_unaligned_le32(&buf[0x3c]); 211 212 /* 213 * Size of code: Subtract the size of the first sector (512 bytes) 214 * which includes the header. 215 */ 216 put_unaligned_le32(file_sz - 512, &buf[pe_header + 0x1c]); 217 218 /* 219 * Address of entry point for PE/COFF executable 220 */ 221 put_unaligned_le32(text_start + efi_pe_entry, &buf[pe_header + 0x28]); 222 223 update_pecoff_section_header(".text", text_start, text_sz); 224 } 225 226 static void update_pecoff_bss(unsigned int file_sz, unsigned int init_sz) 227 { 228 unsigned int pe_header; 229 unsigned int bss_sz = init_sz - file_sz; 230 231 pe_header = get_unaligned_le32(&buf[0x3c]); 232 233 /* Size of uninitialized data */ 234 put_unaligned_le32(bss_sz, &buf[pe_header + 0x24]); 235 236 /* Size of image */ 237 put_unaligned_le32(init_sz, &buf[pe_header + 0x50]); 238 239 update_pecoff_section_header_fields(".bss", file_sz, bss_sz, 0, 0); 240 } 241 242 static int reserve_pecoff_reloc_section(int c) 243 { 244 /* Reserve 0x20 bytes for .reloc section */ 245 memset(buf+c, 0, PECOFF_RELOC_RESERVE); 246 return PECOFF_RELOC_RESERVE; 247 } 248 249 static void efi_stub_defaults(void) 250 { 251 /* Defaults for old kernel */ 252 #ifdef CONFIG_X86_32 253 efi_pe_entry = 0x10; 254 #else 255 efi_pe_entry = 0x210; 256 startup_64 = 0x200; 257 #endif 258 } 259 260 static void efi_stub_entry_update(void) 261 { 262 unsigned long addr = efi32_stub_entry; 263 264 #ifdef CONFIG_X86_64 265 /* Yes, this is really how we defined it :( */ 266 addr = efi64_stub_entry - 0x200; 267 #endif 268 269 #ifdef CONFIG_EFI_MIXED 270 if (efi32_stub_entry != addr) 271 die("32-bit and 64-bit EFI entry points do not match\n"); 272 #endif 273 put_unaligned_le32(addr, &buf[0x264]); 274 } 275 276 #else 277 278 static inline void update_pecoff_setup_and_reloc(unsigned int size) {} 279 static inline void update_pecoff_text(unsigned int text_start, 280 unsigned int file_sz) {} 281 static inline void update_pecoff_bss(unsigned int file_sz, 282 unsigned int init_sz) {} 283 static inline void efi_stub_defaults(void) {} 284 static inline void efi_stub_entry_update(void) {} 285 286 static inline int reserve_pecoff_reloc_section(int c) 287 { 288 return 0; 289 } 290 #endif /* CONFIG_EFI_STUB */ 291 292 293 /* 294 * Parse zoffset.h and find the entry points. We could just #include zoffset.h 295 * but that would mean tools/build would have to be rebuilt every time. It's 296 * not as if parsing it is hard... 297 */ 298 #define PARSE_ZOFS(p, sym) do { \ 299 if (!strncmp(p, "#define ZO_" #sym " ", 11+sizeof(#sym))) \ 300 sym = strtoul(p + 11 + sizeof(#sym), NULL, 16); \ 301 } while (0) 302 303 static void parse_zoffset(char *fname) 304 { 305 FILE *file; 306 char *p; 307 int c; 308 309 file = fopen(fname, "r"); 310 if (!file) 311 die("Unable to open `%s': %m", fname); 312 c = fread(buf, 1, sizeof(buf) - 1, file); 313 if (ferror(file)) 314 die("read-error on `zoffset.h'"); 315 fclose(file); 316 buf[c] = 0; 317 318 p = (char *)buf; 319 320 while (p && *p) { 321 PARSE_ZOFS(p, efi32_stub_entry); 322 PARSE_ZOFS(p, efi64_stub_entry); 323 PARSE_ZOFS(p, efi_pe_entry); 324 PARSE_ZOFS(p, startup_64); 325 326 p = strchr(p, '\n'); 327 while (p && (*p == '\r' || *p == '\n')) 328 p++; 329 } 330 } 331 332 int main(int argc, char ** argv) 333 { 334 unsigned int i, sz, setup_sectors, init_sz; 335 int c; 336 u32 sys_size; 337 struct stat sb; 338 FILE *file, *dest; 339 int fd; 340 void *kernel; 341 u32 crc = 0xffffffffUL; 342 343 efi_stub_defaults(); 344 345 if (argc != 5) 346 usage(); 347 parse_zoffset(argv[3]); 348 349 dest = fopen(argv[4], "w"); 350 if (!dest) 351 die("Unable to write `%s': %m", argv[4]); 352 353 /* Copy the setup code */ 354 file = fopen(argv[1], "r"); 355 if (!file) 356 die("Unable to open `%s': %m", argv[1]); 357 c = fread(buf, 1, sizeof(buf), file); 358 if (ferror(file)) 359 die("read-error on `setup'"); 360 if (c < 1024) 361 die("The setup must be at least 1024 bytes"); 362 if (get_unaligned_le16(&buf[510]) != 0xAA55) 363 die("Boot block hasn't got boot flag (0xAA55)"); 364 fclose(file); 365 366 c += reserve_pecoff_reloc_section(c); 367 368 /* Pad unused space with zeros */ 369 setup_sectors = (c + 511) / 512; 370 if (setup_sectors < SETUP_SECT_MIN) 371 setup_sectors = SETUP_SECT_MIN; 372 i = setup_sectors*512; 373 memset(buf+c, 0, i-c); 374 375 update_pecoff_setup_and_reloc(i); 376 377 /* Set the default root device */ 378 put_unaligned_le16(DEFAULT_ROOT_DEV, &buf[508]); 379 380 printf("Setup is %d bytes (padded to %d bytes).\n", c, i); 381 382 /* Open and stat the kernel file */ 383 fd = open(argv[2], O_RDONLY); 384 if (fd < 0) 385 die("Unable to open `%s': %m", argv[2]); 386 if (fstat(fd, &sb)) 387 die("Unable to stat `%s': %m", argv[2]); 388 sz = sb.st_size; 389 printf("System is %d kB\n", (sz+1023)/1024); 390 kernel = mmap(NULL, sz, PROT_READ, MAP_SHARED, fd, 0); 391 if (kernel == MAP_FAILED) 392 die("Unable to mmap '%s': %m", argv[2]); 393 /* Number of 16-byte paragraphs, including space for a 4-byte CRC */ 394 sys_size = (sz + 15 + 4) / 16; 395 #ifdef CONFIG_EFI_STUB 396 /* 397 * COFF requires minimum 32-byte alignment of sections, and 398 * adding a signature is problematic without that alignment. 399 */ 400 sys_size = (sys_size + 1) & ~1; 401 #endif 402 403 /* Patch the setup code with the appropriate size parameters */ 404 buf[0x1f1] = setup_sectors-1; 405 put_unaligned_le32(sys_size, &buf[0x1f4]); 406 407 update_pecoff_text(setup_sectors * 512, i + (sys_size * 16)); 408 init_sz = get_unaligned_le32(&buf[0x260]); 409 update_pecoff_bss(i + (sys_size * 16), init_sz); 410 411 efi_stub_entry_update(); 412 413 crc = partial_crc32(buf, i, crc); 414 if (fwrite(buf, 1, i, dest) != i) 415 die("Writing setup failed"); 416 417 /* Copy the kernel code */ 418 crc = partial_crc32(kernel, sz, crc); 419 if (fwrite(kernel, 1, sz, dest) != sz) 420 die("Writing kernel failed"); 421 422 /* Add padding leaving 4 bytes for the checksum */ 423 while (sz++ < (sys_size*16) - 4) { 424 crc = partial_crc32_one('\0', crc); 425 if (fwrite("\0", 1, 1, dest) != 1) 426 die("Writing padding failed"); 427 } 428 429 /* Write the CRC */ 430 printf("CRC %x\n", crc); 431 put_unaligned_le32(crc, buf); 432 if (fwrite(buf, 1, 4, dest) != 4) 433 die("Writing CRC failed"); 434 435 /* Catch any delayed write failures */ 436 if (fclose(dest)) 437 die("Writing image failed"); 438 439 close(fd); 440 441 /* Everything is OK */ 442 return 0; 443 } 444