arch/x86/boot/tools/build.c

   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 #ifdef CONFIG_EFI_MIXED
  57 #define PECOFF_COMPAT_RESERVE 0x20
  58 #else
  59 #define PECOFF_COMPAT_RESERVE 0x0
  60 #endif
  61
  62 static unsigned long efi32_stub_entry;
  63 static unsigned long efi64_stub_entry;
  64 static unsigned long efi_pe_entry;
  65 static unsigned long efi32_pe_entry;
  66 static unsigned long kernel_info;
  67 static unsigned long startup_64;
  68 static unsigned long _ehead;
  69 static unsigned long _end;
  70
  71 /*----------------------------------------------------------------------*/
  72
  73 static 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
 128 static u32 partial_crc32_one(u8 c, u32 crc)
 129 {
 130         return crctab32[(crc ^ c) & 0xff] ^ (crc >> 8);
 131 }
 132
 133 static 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
 140 static 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
 150 static void usage(void)
 151 {
 152         die("Usage: build setup system zoffset.h image");
 153 }
 154
 155 #ifdef CONFIG_EFI_STUB
 156
 157 static 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
 193 static 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
 198 static 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
 232 static 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
 271 static 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
 278 static 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
 289 static 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
 307 static inline void update_pecoff_setup_and_reloc(unsigned int size) {}
 308 static inline void update_pecoff_text(unsigned int text_start,
 309                                       unsigned int file_sz,
 310                                       unsigned int init_sz) {}
 311 static inline void efi_stub_defaults(void) {}
 312 static inline void efi_stub_entry_update(void) {}
 313
 314 static inline int reserve_pecoff_reloc_section(int c)
 315 {
 316         return 0;
 317 }
 318 #endif /* CONFIG_EFI_STUB */
 319
 320 static 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
 337 static 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
 370 int 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 }