summaryrefslogtreecommitdiff
path: root/package/aboot/src/tools/objstrip.c
blob: 19612644bb3b172677fbfe3f4784b8cf0823978e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
/*
 * arch/alpha/boot/tools/objstrip.c
 *
 * Strip the object file headers/trailers from an executable (ELF).
 *
 * Copyright (C) 1996 David Mosberger-Tang.
 */
/*
 * Converts an ELF object file into a bootable file.  The
 * object file must be a OMAGIC file (i.e., data and bss follow immediatly
 * behind the text).  See DEC "Assembly Language Programmer's Guide"
 * documentation for details.  The SRM boot process is documented in
 * the Alpha AXP Architecture Reference Manual, Second Edition by
 * Richard L. Sites and Richard T. Witek.
 */
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>

#include <sys/fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>

#include <a.out.h>
#include <linux/coff.h>
#include <linux/param.h>
#include <string.h>

#ifdef __ELF__
# include <linux/elf.h>
# include <linux/version.h>
# if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
#  define elf_check_arch(x) ((x)->e_machine == EM_ALPHA)
# endif
# if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
#  define aboot_elf_check_arch(e)        elf_check_arch(e)
# else
#  define aboot_elf_check_arch(e)        elf_check_arch(e->e_machine)
# endif
#endif

/* bootfile size must be multiple of BLOCK_SIZE: */
#define BLOCK_SIZE	512

const char * prog_name;


void
usage (void)
{
    fprintf(stderr,
	    "usage: %s [-v] -p file primary\n"
	    "       %s [-vb] file [secondary]\n", prog_name, prog_name);
    exit(1);
}


int
main (int argc, char *argv[])
{
    size_t nwritten, tocopy, n, mem_size, fil_size, pad = 0;
    int fd, ofd, i, j, verbose = 0, primary = 0;
    char buf[8192], *inname;
    struct exec * aout;		/* includes file & aout header */
    long offset;
#ifdef __ELF__
    struct elf64_hdr *elf;
    struct elf64_phdr *elf_phdr;	/* program header */
    unsigned long long e_entry;
#endif

    prog_name = argv[0];

    for (i = 1; i < argc && argv[i][0] == '-'; ++i) {
	for (j = 1; argv[i][j]; ++j) {
	    switch (argv[i][j]) {
	      case 'v':
		  verbose = ~verbose;
		  break;

	      case 'b':
		  pad = BLOCK_SIZE;
		  break;

	      case 'p':
		  primary = 1;		/* make primary bootblock */
		  break;
	    }
	}
    }

    if (i >= argc) {
	usage();
    }
    inname = argv[i++];

    fd = open(inname, O_RDONLY);
    if (fd == -1) {
	perror("open");
	exit(1);
    }

    ofd = 1;
    if (i < argc) {
	ofd = open(argv[i++], O_WRONLY | O_CREAT | O_TRUNC, 0666);
	if (fd == -1) {
	    perror("open");
	    exit(1);
	}
    }

    if (primary) {
	/* generate bootblock for primary loader */
	
	unsigned long bb[64], sum = 0;
	struct stat st;
	off_t size;
	int i;

	if (ofd == 1) {
	    usage();
	}

	if (fstat(fd, &st) == -1) {
	    perror("fstat");
	    exit(1);
	}

	size = (st.st_size + BLOCK_SIZE - 1) & ~(BLOCK_SIZE - 1);
	memset(bb, 0, sizeof(bb));
	strcpy((char *) bb, "Linux SRM bootblock");
	bb[60] = size / BLOCK_SIZE;	/* count */
	bb[61] = 1;			/* starting sector # */
	bb[62] = 0;			/* flags---must be 0 */
	for (i = 0; i < 63; ++i) {
	    sum += bb[i];
	}
	bb[63] = sum;
	if (write(ofd, bb, sizeof(bb)) != sizeof(bb)) {
	    perror("boot-block write");
	    exit(1);
	}
	printf("%lu\n", size);
	return 0;
    }

    /* read and inspect exec header: */

    if (read(fd, buf, sizeof(buf)) < 0) {
	perror("read");
	exit(1);
    }

#ifdef __ELF__
    elf = (struct elf64_hdr *) buf;

    if (elf->e_ident[0] == 0x7f && strncmp(elf->e_ident + 1, "ELF", 3) == 0) {
	if (elf->e_type != ET_EXEC) {
	    fprintf(stderr, "%s: %s is not an ELF executable\n",
		    prog_name, inname);
	    exit(1);
	}
	if (!aboot_elf_check_arch(elf)) {
	    fprintf(stderr, "%s: is not for this processor (e_machine=%d)\n",
		    prog_name, elf->e_machine);
	    exit(1);
	}
	if (elf->e_phnum != 1) {
	    fprintf(stderr,
		    "%s: %d program headers (forgot to link with -N?)\n",
		    prog_name, elf->e_phnum);
	}

	e_entry = elf->e_entry;

	lseek(fd, elf->e_phoff, SEEK_SET);
	if (read(fd, buf, sizeof(*elf_phdr)) != sizeof(*elf_phdr)) {
	    perror("read");
	    exit(1);
	}

	elf_phdr = (struct elf64_phdr *) buf;
	offset	 = elf_phdr->p_offset;
	mem_size = elf_phdr->p_memsz;
	fil_size = elf_phdr->p_filesz;

	/* work around ELF bug: */
	if (elf_phdr->p_vaddr < e_entry) {
	    unsigned long delta = e_entry - elf_phdr->p_vaddr;
	    offset   += delta;
	    mem_size -= delta;
	    fil_size -= delta;
	    elf_phdr->p_vaddr += delta;
	}

	if (verbose) {
	    fprintf(stderr, "%s: extracting %#016lx-%#016lx (at %lx)\n",
		    prog_name, (long) elf_phdr->p_vaddr,
		    elf_phdr->p_vaddr + fil_size, offset);
	}
    }
#endif

    if (lseek(fd, offset, SEEK_SET) != offset) {
	perror("lseek");
	exit(1);
    }

    if (verbose) {
	fprintf(stderr, "%s: copying %lu byte from %s\n",
		prog_name, (unsigned long) fil_size, inname);
    }

    tocopy = fil_size;
    while (tocopy > 0) {
	n = tocopy;
	if (n > sizeof(buf)) {
	    n = sizeof(buf);
	}
	tocopy -= n;
	if ((size_t) read(fd, buf, n) != n) {
	    perror("read");
	    exit(1);
	}
	do {
	    nwritten = write(ofd, buf, n);
	    if ((ssize_t) nwritten == -1) {
		perror("write");
		exit(1);
	    }
	    n -= nwritten;
	} while (n > 0);
    }

    if (pad) {
	mem_size = ((mem_size + pad - 1) / pad) * pad;
    }

    tocopy = mem_size - fil_size;
    if (tocopy > 0) {
	fprintf(stderr,
		"%s: zero-filling bss and aligning to %lu with %lu bytes\n",
		prog_name, pad, (unsigned long) tocopy);

	memset(buf, 0x00, sizeof(buf));
	do {
	    n = tocopy;
	    if (n > sizeof(buf)) {
		n = sizeof(buf);
	    }
	    nwritten = write(ofd, buf, n);
	    if ((ssize_t) nwritten == -1) {
		perror("write");
		exit(1);
	    }
	    tocopy -= nwritten;
	} while (tocopy > 0);
    }
    return 0;
}