1
2
3
4
5
6
7
8
9
10
11
12
13
14
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#ifdef __ELF__
29# include <linux/elf.h>
30# define elfhdr elf64_hdr
31# define elf_phdr elf64_phdr
32# define elf_check_arch(x) ((x)->e_machine == EM_ALPHA)
33#endif
34
35
36#define BLOCK_SIZE 512
37
38const char * prog_name;
39
40
41static void
42usage (void)
43{
44 fprintf(stderr,
45 "usage: %s [-v] -p file primary\n"
46 " %s [-vb] file [secondary]\n", prog_name, prog_name);
47 exit(1);
48}
49
50
51int
52main (int argc, char *argv[])
53{
54 size_t nwritten, tocopy, n, mem_size, fil_size, pad = 0;
55 int fd, ofd, i, j, verbose = 0, primary = 0;
56 char buf[8192], *inname;
57 struct exec * aout;
58 long offset;
59#ifdef __ELF__
60 struct elfhdr *elf;
61 struct elf_phdr *elf_phdr;
62 unsigned long long e_entry;
63#endif
64
65 prog_name = argv[0];
66
67 for (i = 1; i < argc && argv[i][0] == '-'; ++i) {
68 for (j = 1; argv[i][j]; ++j) {
69 switch (argv[i][j]) {
70 case 'v':
71 verbose = ~verbose;
72 break;
73
74 case 'b':
75 pad = BLOCK_SIZE;
76 break;
77
78 case 'p':
79 primary = 1;
80 break;
81 }
82 }
83 }
84
85 if (i >= argc) {
86 usage();
87 }
88 inname = argv[i++];
89
90 fd = open(inname, O_RDONLY);
91 if (fd == -1) {
92 perror("open");
93 exit(1);
94 }
95
96 ofd = 1;
97 if (i < argc) {
98 ofd = open(argv[i++], O_WRONLY | O_CREAT | O_TRUNC, 0666);
99 if (ofd == -1) {
100 perror("open");
101 exit(1);
102 }
103 }
104
105 if (primary) {
106
107
108 unsigned long bb[64], sum = 0;
109 struct stat st;
110 off_t size;
111 int i;
112
113 if (ofd == 1) {
114 usage();
115 }
116
117 if (fstat(fd, &st) == -1) {
118 perror("fstat");
119 exit(1);
120 }
121
122 size = (st.st_size + BLOCK_SIZE - 1) & ~(BLOCK_SIZE - 1);
123 memset(bb, 0, sizeof(bb));
124 strcpy((char *) bb, "Linux SRM bootblock");
125 bb[60] = size / BLOCK_SIZE;
126 bb[61] = 1;
127 bb[62] = 0;
128 for (i = 0; i < 63; ++i) {
129 sum += bb[i];
130 }
131 bb[63] = sum;
132 if (write(ofd, bb, sizeof(bb)) != sizeof(bb)) {
133 perror("boot-block write");
134 exit(1);
135 }
136 printf("%lu\n", size);
137 return 0;
138 }
139
140
141
142 if (read(fd, buf, sizeof(buf)) < 0) {
143 perror("read");
144 exit(1);
145 }
146
147#ifdef __ELF__
148 elf = (struct elfhdr *) buf;
149
150 if (elf->e_ident[0] == 0x7f && strncmp((char *)elf->e_ident + 1, "ELF", 3) == 0) {
151 if (elf->e_type != ET_EXEC) {
152 fprintf(stderr, "%s: %s is not an ELF executable\n",
153 prog_name, inname);
154 exit(1);
155 }
156 if (!elf_check_arch(elf)) {
157 fprintf(stderr, "%s: is not for this processor (e_machine=%d)\n",
158 prog_name, elf->e_machine);
159 exit(1);
160 }
161 if (elf->e_phnum != 1) {
162 fprintf(stderr,
163 "%s: %d program headers (forgot to link with -N?)\n",
164 prog_name, elf->e_phnum);
165 }
166
167 e_entry = elf->e_entry;
168
169 lseek(fd, elf->e_phoff, SEEK_SET);
170 if (read(fd, buf, sizeof(*elf_phdr)) != sizeof(*elf_phdr)) {
171 perror("read");
172 exit(1);
173 }
174
175 elf_phdr = (struct elf_phdr *) buf;
176 offset = elf_phdr->p_offset;
177 mem_size = elf_phdr->p_memsz;
178 fil_size = elf_phdr->p_filesz;
179
180
181 if (elf_phdr->p_vaddr < e_entry) {
182 unsigned long delta = e_entry - elf_phdr->p_vaddr;
183 offset += delta;
184 mem_size -= delta;
185 fil_size -= delta;
186 elf_phdr->p_vaddr += delta;
187 }
188
189 if (verbose) {
190 fprintf(stderr, "%s: extracting %#016lx-%#016lx (at %lx)\n",
191 prog_name, (long) elf_phdr->p_vaddr,
192 elf_phdr->p_vaddr + fil_size, offset);
193 }
194 } else
195#endif
196 {
197 aout = (struct exec *) buf;
198
199 if (!(aout->fh.f_flags & COFF_F_EXEC)) {
200 fprintf(stderr, "%s: %s is not in executable format\n",
201 prog_name, inname);
202 exit(1);
203 }
204
205 if (aout->fh.f_opthdr != sizeof(aout->ah)) {
206 fprintf(stderr, "%s: %s has unexpected optional header size\n",
207 prog_name, inname);
208 exit(1);
209 }
210
211 if (N_MAGIC(*aout) != OMAGIC) {
212 fprintf(stderr, "%s: %s is not an OMAGIC file\n",
213 prog_name, inname);
214 exit(1);
215 }
216 offset = N_TXTOFF(*aout);
217 fil_size = aout->ah.tsize + aout->ah.dsize;
218 mem_size = fil_size + aout->ah.bsize;
219
220 if (verbose) {
221 fprintf(stderr, "%s: extracting %#016lx-%#016lx (at %lx)\n",
222 prog_name, aout->ah.text_start,
223 aout->ah.text_start + fil_size, offset);
224 }
225 }
226
227 if (lseek(fd, offset, SEEK_SET) != offset) {
228 perror("lseek");
229 exit(1);
230 }
231
232 if (verbose) {
233 fprintf(stderr, "%s: copying %lu byte from %s\n",
234 prog_name, (unsigned long) fil_size, inname);
235 }
236
237 tocopy = fil_size;
238 while (tocopy > 0) {
239 n = tocopy;
240 if (n > sizeof(buf)) {
241 n = sizeof(buf);
242 }
243 tocopy -= n;
244 if ((size_t) read(fd, buf, n) != n) {
245 perror("read");
246 exit(1);
247 }
248 do {
249 nwritten = write(ofd, buf, n);
250 if ((ssize_t) nwritten == -1) {
251 perror("write");
252 exit(1);
253 }
254 n -= nwritten;
255 } while (n > 0);
256 }
257
258 if (pad) {
259 mem_size = ((mem_size + pad - 1) / pad) * pad;
260 }
261
262 tocopy = mem_size - fil_size;
263 if (tocopy > 0) {
264 fprintf(stderr,
265 "%s: zero-filling bss and aligning to %lu with %lu bytes\n",
266 prog_name, pad, (unsigned long) tocopy);
267
268 memset(buf, 0x00, sizeof(buf));
269 do {
270 n = tocopy;
271 if (n > sizeof(buf)) {
272 n = sizeof(buf);
273 }
274 nwritten = write(ofd, buf, n);
275 if ((ssize_t) nwritten == -1) {
276 perror("write");
277 exit(1);
278 }
279 tocopy -= nwritten;
280 } while (tocopy > 0);
281 }
282 return 0;
283}
284
