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_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
update_pecoff_setup_and_reloc(unsigned int size)307 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)308 static inline void update_pecoff_text(unsigned int text_start,
309 unsigned int file_sz,
310 unsigned int init_sz) {}
efi_stub_defaults(void)311 static inline void efi_stub_defaults(void) {}
efi_stub_entry_update(void)312 static inline void efi_stub_entry_update(void) {}
313
reserve_pecoff_reloc_section(int c)314 static inline int reserve_pecoff_reloc_section(int c)
315 {
316 return 0;
317 }
318 #endif /* CONFIG_EFI_STUB */
319
reserve_pecoff_compat_section(int c)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
parse_zoffset(char * fname)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
main(int argc,char ** argv)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 }
501