1 /*
2 * arch/alpha/boot/tools/objstrip.c
3 *
4 * Strip the object file headers/trailers from an executable (ELF or ECOFF).
5 *
6 * Copyright (C) 1996 David Mosberger-Tang.
7 */
8 /*
9 * Converts an ECOFF or ELF object file into a bootable file. The
10 * object file must be a OMAGIC file (i.e., data and bss follow immediatly
11 * behind the text). See DEC "Assembly Language Programmer's Guide"
12 * documentation for details. The SRM boot process is documented in
13 * the Alpha AXP Architecture Reference Manual, Second Edition by
14 * Richard L. Sites and Richard T. Witek.
15 */
16 #include <stdio.h>
17 #include <string.h>
18 #include <stdlib.h>
19 #include <unistd.h>
20
21 #include <sys/fcntl.h>
22 #include <sys/stat.h>
23 #include <sys/types.h>
24
25 #include <linux/a.out.h>
26 #include <linux/coff.h>
27 #include <linux/param.h>
28 #include <linux/string.h>
29 #ifdef __ELF__
30 # include <linux/elf.h>
31 #endif
32
33 /* bootfile size must be multiple of BLOCK_SIZE: */
34 #define BLOCK_SIZE 512
35
36 const char * prog_name;
37
38
39 void
usage(void)40 usage (void)
41 {
42 fprintf(stderr,
43 "usage: %s [-v] -p file primary\n"
44 " %s [-vb] file [secondary]\n", prog_name, prog_name);
45 exit(1);
46 }
47
48
49 int
main(int argc,char * argv[])50 main (int argc, char *argv[])
51 {
52 size_t nwritten, tocopy, n, mem_size, fil_size, pad = 0;
53 int fd, ofd, i, j, verbose = 0, primary = 0;
54 char buf[8192], *inname;
55 struct exec * aout; /* includes file & aout header */
56 long offset;
57 #ifdef __ELF__
58 struct elfhdr *elf;
59 struct elf_phdr *elf_phdr; /* program header */
60 unsigned long long e_entry;
61 #endif
62
63 prog_name = argv[0];
64
65 for (i = 1; i < argc && argv[i][0] == '-'; ++i) {
66 for (j = 1; argv[i][j]; ++j) {
67 switch (argv[i][j]) {
68 case 'v':
69 verbose = ~verbose;
70 break;
71
72 case 'b':
73 pad = BLOCK_SIZE;
74 break;
75
76 case 'p':
77 primary = 1; /* make primary bootblock */
78 break;
79 }
80 }
81 }
82
83 if (i >= argc) {
84 usage();
85 }
86 inname = argv[i++];
87
88 fd = open(inname, O_RDONLY);
89 if (fd == -1) {
90 perror("open");
91 exit(1);
92 }
93
94 ofd = 1;
95 if (i < argc) {
96 ofd = open(argv[i++], O_WRONLY | O_CREAT | O_TRUNC, 0666);
97 if (fd == -1) {
98 perror("open");
99 exit(1);
100 }
101 }
102
103 if (primary) {
104 /* generate bootblock for primary loader */
105
106 unsigned long bb[64], sum = 0;
107 struct stat st;
108 off_t size;
109 int i;
110
111 if (ofd == 1) {
112 usage();
113 }
114
115 if (fstat(fd, &st) == -1) {
116 perror("fstat");
117 exit(1);
118 }
119
120 size = (st.st_size + BLOCK_SIZE - 1) & ~(BLOCK_SIZE - 1);
121 memset(bb, 0, sizeof(bb));
122 strcpy((char *) bb, "Linux SRM bootblock");
123 bb[60] = size / BLOCK_SIZE; /* count */
124 bb[61] = 1; /* starting sector # */
125 bb[62] = 0; /* flags---must be 0 */
126 for (i = 0; i < 63; ++i) {
127 sum += bb[i];
128 }
129 bb[63] = sum;
130 if (write(ofd, bb, sizeof(bb)) != sizeof(bb)) {
131 perror("boot-block write");
132 exit(1);
133 }
134 printf("%lu\n", size);
135 return 0;
136 }
137
138 /* read and inspect exec header: */
139
140 if (read(fd, buf, sizeof(buf)) < 0) {
141 perror("read");
142 exit(1);
143 }
144
145 #ifdef __ELF__
146 elf = (struct elfhdr *) buf;
147
148 if (elf->e_ident[0] == 0x7f && strncmp(elf->e_ident + 1, "ELF", 3) == 0) {
149 if (elf->e_type != ET_EXEC) {
150 fprintf(stderr, "%s: %s is not an ELF executable\n",
151 prog_name, inname);
152 exit(1);
153 }
154 if (!elf_check_arch(elf)) {
155 fprintf(stderr, "%s: is not for this processor (e_machine=%d)\n",
156 prog_name, elf->e_machine);
157 exit(1);
158 }
159 if (elf->e_phnum != 1) {
160 fprintf(stderr,
161 "%s: %d program headers (forgot to link with -N?)\n",
162 prog_name, elf->e_phnum);
163 }
164
165 e_entry = elf->e_entry;
166
167 lseek(fd, elf->e_phoff, SEEK_SET);
168 if (read(fd, buf, sizeof(*elf_phdr)) != sizeof(*elf_phdr)) {
169 perror("read");
170 exit(1);
171 }
172
173 elf_phdr = (struct elf_phdr *) buf;
174 offset = elf_phdr->p_offset;
175 mem_size = elf_phdr->p_memsz;
176 fil_size = elf_phdr->p_filesz;
177
178 /* work around ELF bug: */
179 if (elf_phdr->p_vaddr < e_entry) {
180 unsigned long delta = e_entry - elf_phdr->p_vaddr;
181 offset += delta;
182 mem_size -= delta;
183 fil_size -= delta;
184 elf_phdr->p_vaddr += delta;
185 }
186
187 if (verbose) {
188 fprintf(stderr, "%s: extracting %#016lx-%#016lx (at %lx)\n",
189 prog_name, (long) elf_phdr->p_vaddr,
190 elf_phdr->p_vaddr + fil_size, offset);
191 }
192 } else
193 #endif
194 {
195 aout = (struct exec *) buf;
196
197 if (!(aout->fh.f_flags & COFF_F_EXEC)) {
198 fprintf(stderr, "%s: %s is not in executable format\n",
199 prog_name, inname);
200 exit(1);
201 }
202
203 if (aout->fh.f_opthdr != sizeof(aout->ah)) {
204 fprintf(stderr, "%s: %s has unexpected optional header size\n",
205 prog_name, inname);
206 exit(1);
207 }
208
209 if (N_MAGIC(*aout) != OMAGIC) {
210 fprintf(stderr, "%s: %s is not an OMAGIC file\n",
211 prog_name, inname);
212 exit(1);
213 }
214 offset = N_TXTOFF(*aout);
215 fil_size = aout->ah.tsize + aout->ah.dsize;
216 mem_size = fil_size + aout->ah.bsize;
217
218 if (verbose) {
219 fprintf(stderr, "%s: extracting %#016lx-%#016lx (at %lx)\n",
220 prog_name, aout->ah.text_start,
221 aout->ah.text_start + fil_size, offset);
222 }
223 }
224
225 if (lseek(fd, offset, SEEK_SET) != offset) {
226 perror("lseek");
227 exit(1);
228 }
229
230 if (verbose) {
231 fprintf(stderr, "%s: copying %lu byte from %s\n",
232 prog_name, (unsigned long) fil_size, inname);
233 }
234
235 tocopy = fil_size;
236 while (tocopy > 0) {
237 n = tocopy;
238 if (n > sizeof(buf)) {
239 n = sizeof(buf);
240 }
241 tocopy -= n;
242 if ((size_t) read(fd, buf, n) != n) {
243 perror("read");
244 exit(1);
245 }
246 do {
247 nwritten = write(ofd, buf, n);
248 if ((ssize_t) nwritten == -1) {
249 perror("write");
250 exit(1);
251 }
252 n -= nwritten;
253 } while (n > 0);
254 }
255
256 if (pad) {
257 mem_size = ((mem_size + pad - 1) / pad) * pad;
258 }
259
260 tocopy = mem_size - fil_size;
261 if (tocopy > 0) {
262 fprintf(stderr,
263 "%s: zero-filling bss and aligning to %lu with %lu bytes\n",
264 prog_name, pad, (unsigned long) tocopy);
265
266 memset(buf, 0x00, sizeof(buf));
267 do {
268 n = tocopy;
269 if (n > sizeof(buf)) {
270 n = sizeof(buf);
271 }
272 nwritten = write(ofd, buf, n);
273 if ((ssize_t) nwritten == -1) {
274 perror("write");
275 exit(1);
276 }
277 tocopy -= nwritten;
278 } while (tocopy > 0);
279 }
280 return 0;
281 }
282