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
partial_crc32_one(u8 c,u32 crc)128 static u32 partial_crc32_one(u8 c, u32 crc)
129 {
130 return crctab32[(crc ^ c) & 0xff] ^ (crc >> 8);
131 }
132
partial_crc32(const u8 * s,int len,u32 crc)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
die(const char * str,...)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
usage(void)150 static void usage(void)
151 {
152 die("Usage: build setup system zoffset.h image");
153 }
154
155 #ifdef CONFIG_EFI_STUB
156
update_pecoff_section_header_fields(char * section_name,u32 vma,u32 size,u32 datasz,u32 offset)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
update_pecoff_section_header(char * section_name,u32 offset,u32 size)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
update_pecoff_setup_and_reloc(unsigned int size)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
update_pecoff_text(unsigned int text_start,unsigned int file_sz,unsigned int init_sz)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
reserve_pecoff_reloc_section(int c)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
efi_stub_defaults(void)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
efi_stub_entry_update(void)289 static void efi_stub_entry_update(void)
290 {
291 unsigned long addr = efi32_stub_entry;
292
293 #ifdef CONFIG_EFI_HANDOVER_PROTOCOL
294 #ifdef CONFIG_X86_64
295 /* Yes, this is really how we defined it :( */
296 addr = efi64_stub_entry - 0x200;
297 #endif
298
299 #ifdef CONFIG_EFI_MIXED
300 if (efi32_stub_entry != addr)
301 die("32-bit and 64-bit EFI entry points do not match\n");
302 #endif
303 #endif
304 put_unaligned_le32(addr, &buf[0x264]);
305 }
306
307 #else
308
update_pecoff_setup_and_reloc(unsigned int size)309 static inline void update_pecoff_setup_and_reloc(unsigned int size) {}
update_pecoff_text(unsigned int text_start,unsigned int file_sz,unsigned int init_sz)310 static inline void update_pecoff_text(unsigned int text_start,
311 unsigned int file_sz,
312 unsigned int init_sz) {}
efi_stub_defaults(void)313 static inline void efi_stub_defaults(void) {}
efi_stub_entry_update(void)314 static inline void efi_stub_entry_update(void) {}
315
reserve_pecoff_reloc_section(int c)316 static inline int reserve_pecoff_reloc_section(int c)
317 {
318 return 0;
319 }
320 #endif /* CONFIG_EFI_STUB */
321
reserve_pecoff_compat_section(int c)322 static int reserve_pecoff_compat_section(int c)
323 {
324 /* Reserve 0x20 bytes for .compat section */
325 memset(buf+c, 0, PECOFF_COMPAT_RESERVE);
326 return PECOFF_COMPAT_RESERVE;
327 }
328
329 /*
330 * Parse zoffset.h and find the entry points. We could just #include zoffset.h
331 * but that would mean tools/build would have to be rebuilt every time. It's
332 * not as if parsing it is hard...
333 */
334 #define PARSE_ZOFS(p, sym) do { \
335 if (!strncmp(p, "#define ZO_" #sym " ", 11+sizeof(#sym))) \
336 sym = strtoul(p + 11 + sizeof(#sym), NULL, 16); \
337 } while (0)
338
parse_zoffset(char * fname)339 static void parse_zoffset(char *fname)
340 {
341 FILE *file;
342 char *p;
343 int c;
344
345 file = fopen(fname, "r");
346 if (!file)
347 die("Unable to open `%s': %m", fname);
348 c = fread(buf, 1, sizeof(buf) - 1, file);
349 if (ferror(file))
350 die("read-error on `zoffset.h'");
351 fclose(file);
352 buf[c] = 0;
353
354 p = (char *)buf;
355
356 while (p && *p) {
357 PARSE_ZOFS(p, efi32_stub_entry);
358 PARSE_ZOFS(p, efi64_stub_entry);
359 PARSE_ZOFS(p, efi_pe_entry);
360 PARSE_ZOFS(p, efi32_pe_entry);
361 PARSE_ZOFS(p, kernel_info);
362 PARSE_ZOFS(p, startup_64);
363 PARSE_ZOFS(p, _ehead);
364 PARSE_ZOFS(p, _end);
365
366 p = strchr(p, '\n');
367 while (p && (*p == '\r' || *p == '\n'))
368 p++;
369 }
370 }
371
main(int argc,char ** argv)372 int main(int argc, char ** argv)
373 {
374 unsigned int i, sz, setup_sectors, init_sz;
375 int c;
376 u32 sys_size;
377 struct stat sb;
378 FILE *file, *dest;
379 int fd;
380 void *kernel;
381 u32 crc = 0xffffffffUL;
382
383 efi_stub_defaults();
384
385 if (argc != 5)
386 usage();
387 parse_zoffset(argv[3]);
388
389 dest = fopen(argv[4], "w");
390 if (!dest)
391 die("Unable to write `%s': %m", argv[4]);
392
393 /* Copy the setup code */
394 file = fopen(argv[1], "r");
395 if (!file)
396 die("Unable to open `%s': %m", argv[1]);
397 c = fread(buf, 1, sizeof(buf), file);
398 if (ferror(file))
399 die("read-error on `setup'");
400 if (c < 1024)
401 die("The setup must be at least 1024 bytes");
402 if (get_unaligned_le16(&buf[510]) != 0xAA55)
403 die("Boot block hasn't got boot flag (0xAA55)");
404 fclose(file);
405
406 c += reserve_pecoff_compat_section(c);
407 c += reserve_pecoff_reloc_section(c);
408
409 /* Pad unused space with zeros */
410 setup_sectors = (c + 511) / 512;
411 if (setup_sectors < SETUP_SECT_MIN)
412 setup_sectors = SETUP_SECT_MIN;
413 i = setup_sectors*512;
414 memset(buf+c, 0, i-c);
415
416 update_pecoff_setup_and_reloc(i);
417
418 /* Set the default root device */
419 put_unaligned_le16(DEFAULT_ROOT_DEV, &buf[508]);
420
421 /* Open and stat the kernel file */
422 fd = open(argv[2], O_RDONLY);
423 if (fd < 0)
424 die("Unable to open `%s': %m", argv[2]);
425 if (fstat(fd, &sb))
426 die("Unable to stat `%s': %m", argv[2]);
427 sz = sb.st_size;
428 kernel = mmap(NULL, sz, PROT_READ, MAP_SHARED, fd, 0);
429 if (kernel == MAP_FAILED)
430 die("Unable to mmap '%s': %m", argv[2]);
431 /* Number of 16-byte paragraphs, including space for a 4-byte CRC */
432 sys_size = (sz + 15 + 4) / 16;
433 #ifdef CONFIG_EFI_STUB
434 /*
435 * COFF requires minimum 32-byte alignment of sections, and
436 * adding a signature is problematic without that alignment.
437 */
438 sys_size = (sys_size + 1) & ~1;
439 #endif
440
441 /* Patch the setup code with the appropriate size parameters */
442 buf[0x1f1] = setup_sectors-1;
443 put_unaligned_le32(sys_size, &buf[0x1f4]);
444
445 init_sz = get_unaligned_le32(&buf[0x260]);
446 #ifdef CONFIG_EFI_STUB
447 /*
448 * The decompression buffer will start at ImageBase. When relocating
449 * the compressed kernel to its end, we must ensure that the head
450 * section does not get overwritten. The head section occupies
451 * [i, i + _ehead), and the destination is [init_sz - _end, init_sz).
452 *
453 * At present these should never overlap, because 'i' is at most 32k
454 * because of SETUP_SECT_MAX, '_ehead' is less than 1k, and the
455 * calculation of INIT_SIZE in boot/header.S ensures that
456 * 'init_sz - _end' is at least 64k.
457 *
458 * For future-proofing, increase init_sz if necessary.
459 */
460
461 if (init_sz - _end < i + _ehead) {
462 init_sz = (i + _ehead + _end + 4095) & ~4095;
463 put_unaligned_le32(init_sz, &buf[0x260]);
464 }
465 #endif
466 update_pecoff_text(setup_sectors * 512, i + (sys_size * 16), init_sz);
467
468 efi_stub_entry_update();
469
470 /* Update kernel_info offset. */
471 put_unaligned_le32(kernel_info, &buf[0x268]);
472
473 crc = partial_crc32(buf, i, crc);
474 if (fwrite(buf, 1, i, dest) != i)
475 die("Writing setup failed");
476
477 /* Copy the kernel code */
478 crc = partial_crc32(kernel, sz, crc);
479 if (fwrite(kernel, 1, sz, dest) != sz)
480 die("Writing kernel failed");
481
482 /* Add padding leaving 4 bytes for the checksum */
483 while (sz++ < (sys_size*16) - 4) {
484 crc = partial_crc32_one('\0', crc);
485 if (fwrite("\0", 1, 1, dest) != 1)
486 die("Writing padding failed");
487 }
488
489 /* Write the CRC */
490 put_unaligned_le32(crc, buf);
491 if (fwrite(buf, 1, 4, dest) != 4)
492 die("Writing CRC failed");
493
494 /* Catch any delayed write failures */
495 if (fclose(dest))
496 die("Writing image failed");
497
498 close(fd);
499
500 /* Everything is OK */
501 return 0;
502 }
503
