build.c revision b663a685831905066e3efcb4c173cd8b3f46228b 
1/*
2 *  Copyright (C) 1991, 1992  Linus Torvalds
3 *  Copyright (C) 1997 Martin Mares
4 *  Copyright (C) 2007 H. Peter Anvin
5 */
6
7/*
8 * This file builds a disk-image from three different files:
9 *
10 * - setup: 8086 machine code, sets up system parm
11 * - system: 80386 code for actual system
12 * - zoffset.h: header with ZO_* defines
13 *
14 * It does some checking that all files are of the correct type, and writes
15 * the result to the specified destination, removing headers and padding to
16 * the right amount. It also writes some system data to stdout.
17 */
18
19/*
20 * Changes by tytso to allow root device specification
21 * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
22 * Cross compiling fixes by Gertjan van Wingerde, July 1996
23 * Rewritten by Martin Mares, April 1997
24 * Substantially overhauled by H. Peter Anvin, April 2007
25 */
26
27#include <stdio.h>
28#include <string.h>
29#include <stdlib.h>
30#include <stdarg.h>
31#include <sys/types.h>
32#include <sys/stat.h>
33#include <unistd.h>
34#include <fcntl.h>
35#include <sys/mman.h>
36#include <tools/le_byteshift.h>
37
38typedef unsigned char  u8;
39typedef unsigned short u16;
40typedef unsigned int   u32;
41
42#define DEFAULT_MAJOR_ROOT 0
43#define DEFAULT_MINOR_ROOT 0
44#define DEFAULT_ROOT_DEV (DEFAULT_MAJOR_ROOT << 8 | DEFAULT_MINOR_ROOT)
45
46/* Minimal number of setup sectors */
47#define SETUP_SECT_MIN 5
48#define SETUP_SECT_MAX 64
49
50/* This must be large enough to hold the entire setup */
51u8 buf[SETUP_SECT_MAX*512];
52int is_big_kernel;
53
54#define PECOFF_RELOC_RESERVE 0x20
55
56unsigned long efi32_stub_entry;
57unsigned long efi64_stub_entry;
58unsigned long efi_pe_entry;
59unsigned long startup_64;
60
61/*----------------------------------------------------------------------*/
62
63static 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
118static u32 partial_crc32_one(u8 c, u32 crc)
119{
120	return crctab32[(crc ^ c) & 0xff] ^ (crc >> 8);
121}
122
123static 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
130static void die(const char * str, ...)
131{
132	va_list args;
133	va_start(args, str);
134	vfprintf(stderr, str, args);
135	fputc('\n', stderr);
136	exit(1);
137}
138
139static void usage(void)
140{
141	die("Usage: build setup system zoffset.h image");
142}
143
144#ifdef CONFIG_EFI_STUB
145
146static void update_pecoff_section_header(char *section_name, u32 offset, u32 size)
147{
148	unsigned int pe_header;
149	unsigned short num_sections;
150	u8 *section;
151
152	pe_header = get_unaligned_le32(&buf[0x3c]);
153	num_sections = get_unaligned_le16(&buf[pe_header + 6]);
154
155#ifdef CONFIG_X86_32
156	section = &buf[pe_header + 0xa8];
157#else
158	section = &buf[pe_header + 0xb8];
159#endif
160
161	while (num_sections > 0) {
162		if (strncmp((char*)section, section_name, 8) == 0) {
163			/* section header size field */
164			put_unaligned_le32(size, section + 0x8);
165
166			/* section header vma field */
167			put_unaligned_le32(offset, section + 0xc);
168
169			/* section header 'size of initialised data' field */
170			put_unaligned_le32(size, section + 0x10);
171
172			/* section header 'file offset' field */
173			put_unaligned_le32(offset, section + 0x14);
174
175			break;
176		}
177		section += 0x28;
178		num_sections--;
179	}
180}
181
182static void update_pecoff_setup_and_reloc(unsigned int size)
183{
184	u32 setup_offset = 0x200;
185	u32 reloc_offset = size - PECOFF_RELOC_RESERVE;
186	u32 setup_size = reloc_offset - setup_offset;
187
188	update_pecoff_section_header(".setup", setup_offset, setup_size);
189	update_pecoff_section_header(".reloc", reloc_offset, PECOFF_RELOC_RESERVE);
190
191	/*
192	 * Modify .reloc section contents with a single entry. The
193	 * relocation is applied to offset 10 of the relocation section.
194	 */
195	put_unaligned_le32(reloc_offset + 10, &buf[reloc_offset]);
196	put_unaligned_le32(10, &buf[reloc_offset + 4]);
197}
198
199static void update_pecoff_text(unsigned int text_start, unsigned int file_sz)
200{
201	unsigned int pe_header;
202	unsigned int text_sz = file_sz - text_start;
203
204	pe_header = get_unaligned_le32(&buf[0x3c]);
205
206	/* Size of image */
207	put_unaligned_le32(file_sz, &buf[pe_header + 0x50]);
208
209	/*
210	 * Size of code: Subtract the size of the first sector (512 bytes)
211	 * which includes the header.
212	 */
213	put_unaligned_le32(file_sz - 512, &buf[pe_header + 0x1c]);
214
215	/*
216	 * Address of entry point for PE/COFF executable
217	 */
218	put_unaligned_le32(text_start + efi_pe_entry, &buf[pe_header + 0x28]);
219
220	update_pecoff_section_header(".text", text_start, text_sz);
221}
222
223static int reserve_pecoff_reloc_section(int c)
224{
225	/* Reserve 0x20 bytes for .reloc section */
226	memset(buf+c, 0, PECOFF_RELOC_RESERVE);
227	return PECOFF_RELOC_RESERVE;
228}
229
230static void efi_stub_defaults(void)
231{
232	/* Defaults for old kernel */
233#ifdef CONFIG_X86_32
234	efi_pe_entry = 0x10;
235#else
236	efi_pe_entry = 0x210;
237	startup_64 = 0x200;
238#endif
239}
240
241static void efi_stub_entry_update(void)
242{
243	unsigned long addr = efi32_stub_entry;
244
245#ifdef CONFIG_X86_64
246	/* Yes, this is really how we defined it :( */
247	addr = efi64_stub_entry - 0x200;
248#endif
249
250#ifdef CONFIG_EFI_MIXED
251	if (efi32_stub_entry != addr)
252		die("32-bit and 64-bit EFI entry points do not match\n");
253#endif
254	put_unaligned_le32(addr, &buf[0x264]);
255}
256
257#else
258
259static inline void update_pecoff_setup_and_reloc(unsigned int size) {}
260static inline void update_pecoff_text(unsigned int text_start,
261				      unsigned int file_sz) {}
262static inline void efi_stub_defaults(void) {}
263static inline void efi_stub_entry_update(void) {}
264
265static inline int reserve_pecoff_reloc_section(int c)
266{
267	return 0;
268}
269#endif /* CONFIG_EFI_STUB */
270
271
272/*
273 * Parse zoffset.h and find the entry points. We could just #include zoffset.h
274 * but that would mean tools/build would have to be rebuilt every time. It's
275 * not as if parsing it is hard...
276 */
277#define PARSE_ZOFS(p, sym) do { \
278	if (!strncmp(p, "#define ZO_" #sym " ", 11+sizeof(#sym)))	\
279		sym = strtoul(p + 11 + sizeof(#sym), NULL, 16);		\
280} while (0)
281
282static void parse_zoffset(char *fname)
283{
284	FILE *file;
285	char *p;
286	int c;
287
288	file = fopen(fname, "r");
289	if (!file)
290		die("Unable to open `%s': %m", fname);
291	c = fread(buf, 1, sizeof(buf) - 1, file);
292	if (ferror(file))
293		die("read-error on `zoffset.h'");
294	fclose(file);
295	buf[c] = 0;
296
297	p = (char *)buf;
298
299	while (p && *p) {
300		PARSE_ZOFS(p, efi32_stub_entry);
301		PARSE_ZOFS(p, efi64_stub_entry);
302		PARSE_ZOFS(p, efi_pe_entry);
303		PARSE_ZOFS(p, startup_64);
304
305		p = strchr(p, '\n');
306		while (p && (*p == '\r' || *p == '\n'))
307			p++;
308	}
309}
310
311int main(int argc, char ** argv)
312{
313	unsigned int i, sz, setup_sectors;
314	int c;
315	u32 sys_size;
316	struct stat sb;
317	FILE *file, *dest;
318	int fd;
319	void *kernel;
320	u32 crc = 0xffffffffUL;
321
322	efi_stub_defaults();
323
324	if (argc != 5)
325		usage();
326	parse_zoffset(argv[3]);
327
328	dest = fopen(argv[4], "w");
329	if (!dest)
330		die("Unable to write `%s': %m", argv[4]);
331
332	/* Copy the setup code */
333	file = fopen(argv[1], "r");
334	if (!file)
335		die("Unable to open `%s': %m", argv[1]);
336	c = fread(buf, 1, sizeof(buf), file);
337	if (ferror(file))
338		die("read-error on `setup'");
339	if (c < 1024)
340		die("The setup must be at least 1024 bytes");
341	if (get_unaligned_le16(&buf[510]) != 0xAA55)
342		die("Boot block hasn't got boot flag (0xAA55)");
343	fclose(file);
344
345	c += reserve_pecoff_reloc_section(c);
346
347	/* Pad unused space with zeros */
348	setup_sectors = (c + 511) / 512;
349	if (setup_sectors < SETUP_SECT_MIN)
350		setup_sectors = SETUP_SECT_MIN;
351	i = setup_sectors*512;
352	memset(buf+c, 0, i-c);
353
354	update_pecoff_setup_and_reloc(i);
355
356	/* Set the default root device */
357	put_unaligned_le16(DEFAULT_ROOT_DEV, &buf[508]);
358
359	printf("Setup is %d bytes (padded to %d bytes).\n", c, i);
360
361	/* Open and stat the kernel file */
362	fd = open(argv[2], O_RDONLY);
363	if (fd < 0)
364		die("Unable to open `%s': %m", argv[2]);
365	if (fstat(fd, &sb))
366		die("Unable to stat `%s': %m", argv[2]);
367	sz = sb.st_size;
368	printf("System is %d kB\n", (sz+1023)/1024);
369	kernel = mmap(NULL, sz, PROT_READ, MAP_SHARED, fd, 0);
370	if (kernel == MAP_FAILED)
371		die("Unable to mmap '%s': %m", argv[2]);
372	/* Number of 16-byte paragraphs, including space for a 4-byte CRC */
373	sys_size = (sz + 15 + 4) / 16;
374
375	/* Patch the setup code with the appropriate size parameters */
376	buf[0x1f1] = setup_sectors-1;
377	put_unaligned_le32(sys_size, &buf[0x1f4]);
378
379	update_pecoff_text(setup_sectors * 512, sz + i + ((sys_size * 16) - sz));
380
381	efi_stub_entry_update();
382
383	crc = partial_crc32(buf, i, crc);
384	if (fwrite(buf, 1, i, dest) != i)
385		die("Writing setup failed");
386
387	/* Copy the kernel code */
388	crc = partial_crc32(kernel, sz, crc);
389	if (fwrite(kernel, 1, sz, dest) != sz)
390		die("Writing kernel failed");
391
392	/* Add padding leaving 4 bytes for the checksum */
393	while (sz++ < (sys_size*16) - 4) {
394		crc = partial_crc32_one('\0', crc);
395		if (fwrite("\0", 1, 1, dest) != 1)
396			die("Writing padding failed");
397	}
398
399	/* Write the CRC */
400	printf("CRC %x\n", crc);
401	put_unaligned_le32(crc, buf);
402	if (fwrite(buf, 1, 4, dest) != 4)
403		die("Writing CRC failed");
404
405	/* Catch any delayed write failures */
406	if (fclose(dest))
407		die("Writing image failed");
408
409	close(fd);
410
411	/* Everything is OK */
412	return 0;
413}
414