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 immediately
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#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/* bootfile size must be multiple of BLOCK_SIZE: */
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;		/* includes file & aout header */
58    long offset;
59#ifdef __ELF__
60    struct elfhdr *elf;
61    struct elf_phdr *elf_phdr;	/* program header */
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;		/* make primary bootblock */
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	/* generate bootblock for primary loader */
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;	/* count */
126	bb[61] = 1;			/* starting sector # */
127	bb[62] = 0;			/* flags---must be 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    /* read and inspect exec header: */
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	/* work around ELF bug: */
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