Initial revision
[emacs.git] / src / unexencap.c
blob4ffc41145a92ed845f87b0e2968cdc560f9a761b
1 /* Waiting for papers! */
3 /*
4 * Do an unexec() for coff encapsulation. Uses the approach I took
5 * for AKCL, so don't be surprised if it doesn't look too much like
6 * the other unexec() routines. Assumes NO_REMAP. Should be easy to
7 * adapt to the emacs style unexec() if that is desired, but this works
8 * just fine for me with GCC/GAS/GLD under System V. - Jordan
9 */
11 #include <sys/types.h>
12 #include <sys/fcntl.h>
13 #include <sys/file.h>
14 #include <stdio.h>
15 #include "/usr/gnu/lib/gcc/gcc-include/a.out.h"
17 filecpy(to, from, n)
18 FILE *to, *from;
19 register int n;
21 char buffer[BUFSIZ];
23 for (;;)
24 if (n > BUFSIZ) {
25 fread(buffer, BUFSIZ, 1, from);
26 fwrite(buffer, BUFSIZ, 1, to);
27 n -= BUFSIZ;
28 } else if (n > 0) {
29 fread(buffer, 1, n, from);
30 fwrite(buffer, 1, n, to);
31 break;
32 } else
33 break;
35 /* ****************************************************************
36 * unexec
38 * driving logic.
39 * ****************************************************************/
40 unexec (new_name, a_name, data_start, bss_start, entry_address)
41 char *new_name, *a_name;
42 unsigned data_start, bss_start, entry_address;
44 struct coffheader header1;
45 struct coffscn *tp, *dp, *bp;
46 struct exec header;
47 int stsize;
48 char *original_file = a_name;
49 char *save_file = new_name;
51 char *data_begin, *data_end;
52 int original_data;
53 FILE *original, *save;
54 register int n;
55 register char *p;
56 extern char *sbrk();
57 char stdin_buf[BUFSIZ], stdout_buf[BUFSIZ];
60 fclose(stdin);
61 original = fopen(original_file, "r");
62 if (stdin != original || original->_file != 0) {
63 fprintf(stderr, "unexec: Can't open the original file.\n");
64 exit(1);
66 setbuf(original, stdin_buf);
67 fclose(stdout);
68 unlink(save_file);
69 n = open(save_file, O_CREAT|O_WRONLY, 0777);
70 if (n != 1 || (save = fdopen(n, "w")) != stdout) {
71 fprintf(stderr, "unexec: Can't open the save file.\n");
72 exit(1);
74 setbuf(save, stdout_buf);
76 fread(&header1, sizeof(header1), 1, original);
77 tp = &header1.scns[0];
78 dp = &header1.scns[1];
79 bp = &header1.scns[2];
80 fread(&header, sizeof(header), 1, original);
81 data_begin=(char *)N_DATADDR(header);
82 data_end = sbrk(0);
83 original_data = header.a_data;
84 header.a_data = data_end - data_begin;
85 header.a_bss = 0;
86 dp->s_size = header.a_data;
87 bp->s_paddr = dp->s_vaddr + dp->s_size;
88 bp->s_vaddr = bp->s_paddr;
89 bp->s_size = 0;
90 header1.tsize = tp->s_size;
91 header1.dsize = dp->s_size;
92 header1.bsize = bp->s_size;
93 fwrite(&header1, sizeof(header1), 1, save);
94 fwrite(&header, sizeof(header), 1, save);
96 filecpy(save, original, header.a_text);
98 for (n = header.a_data, p = data_begin; ; n -= BUFSIZ, p += BUFSIZ)
99 if (n > BUFSIZ)
100 fwrite(p, BUFSIZ, 1, save);
101 else if (n > 0) {
102 fwrite(p, 1, n, save);
103 break;
104 } else
105 break;
107 fseek(original, original_data, 1);
109 filecpy(save, original, header.a_syms+header.a_trsize+header.a_drsize);
110 fread(&stsize, sizeof(stsize), 1, original);
111 fwrite(&stsize, sizeof(stsize), 1, save);
112 filecpy(save, original, stsize - sizeof(stsize));
114 fclose(original);
115 fclose(save);