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authorJim Blandy <jimb@redhat.com>1992-01-13 22:04:23 +0000
committerJim Blandy <jimb@redhat.com>1992-01-13 22:04:23 +0000
commit31fe8ae4d9ac80da34cf2d714ec5f6626c25ee9a (patch)
treef8f2127ad6d231db883844bf36b1fed70f78f271 /src/unexencap.c
parentbd5cd35fd8b585ad3d87f8be98b45a415fea22c0 (diff)
downloademacs-31fe8ae4d9ac80da34cf2d714ec5f6626c25ee9a.tar.gz
Initial revision
Diffstat (limited to 'src/unexencap.c')
-rw-r--r--src/unexencap.c116
1 files changed, 116 insertions, 0 deletions
diff --git a/src/unexencap.c b/src/unexencap.c
new file mode 100644
index 00000000000..4ffc41145a9
--- /dev/null
+++ b/src/unexencap.c
@@ -0,0 +1,116 @@
+/* Waiting for papers! */
+
+/*
+ * Do an unexec() for coff encapsulation. Uses the approach I took
+ * for AKCL, so don't be surprised if it doesn't look too much like
+ * the other unexec() routines. Assumes NO_REMAP. Should be easy to
+ * adapt to the emacs style unexec() if that is desired, but this works
+ * just fine for me with GCC/GAS/GLD under System V. - Jordan
+ */
+
+#include <sys/types.h>
+#include <sys/fcntl.h>
+#include <sys/file.h>
+#include <stdio.h>
+#include "/usr/gnu/lib/gcc/gcc-include/a.out.h"
+
+filecpy(to, from, n)
+FILE *to, *from;
+register int n;
+{
+ char buffer[BUFSIZ];
+
+ for (;;)
+ if (n > BUFSIZ) {
+ fread(buffer, BUFSIZ, 1, from);
+ fwrite(buffer, BUFSIZ, 1, to);
+ n -= BUFSIZ;
+ } else if (n > 0) {
+ fread(buffer, 1, n, from);
+ fwrite(buffer, 1, n, to);
+ break;
+ } else
+ break;
+}
+/* ****************************************************************
+ * unexec
+ *
+ * driving logic.
+ * ****************************************************************/
+unexec (new_name, a_name, data_start, bss_start, entry_address)
+char *new_name, *a_name;
+unsigned data_start, bss_start, entry_address;
+{
+ struct coffheader header1;
+ struct coffscn *tp, *dp, *bp;
+ struct exec header;
+ int stsize;
+ char *original_file = a_name;
+ char *save_file = new_name;
+
+ char *data_begin, *data_end;
+ int original_data;
+ FILE *original, *save;
+ register int n;
+ register char *p;
+ extern char *sbrk();
+ char stdin_buf[BUFSIZ], stdout_buf[BUFSIZ];
+
+
+ fclose(stdin);
+ original = fopen(original_file, "r");
+ if (stdin != original || original->_file != 0) {
+ fprintf(stderr, "unexec: Can't open the original file.\n");
+ exit(1);
+ }
+ setbuf(original, stdin_buf);
+ fclose(stdout);
+ unlink(save_file);
+ n = open(save_file, O_CREAT|O_WRONLY, 0777);
+ if (n != 1 || (save = fdopen(n, "w")) != stdout) {
+ fprintf(stderr, "unexec: Can't open the save file.\n");
+ exit(1);
+ }
+ setbuf(save, stdout_buf);
+
+ fread(&header1, sizeof(header1), 1, original);
+ tp = &header1.scns[0];
+ dp = &header1.scns[1];
+ bp = &header1.scns[2];
+ fread(&header, sizeof(header), 1, original);
+ data_begin=(char *)N_DATADDR(header);
+ data_end = sbrk(0);
+ original_data = header.a_data;
+ header.a_data = data_end - data_begin;
+ header.a_bss = 0;
+ dp->s_size = header.a_data;
+ bp->s_paddr = dp->s_vaddr + dp->s_size;
+ bp->s_vaddr = bp->s_paddr;
+ bp->s_size = 0;
+ header1.tsize = tp->s_size;
+ header1.dsize = dp->s_size;
+ header1.bsize = bp->s_size;
+ fwrite(&header1, sizeof(header1), 1, save);
+ fwrite(&header, sizeof(header), 1, save);
+
+ filecpy(save, original, header.a_text);
+
+ for (n = header.a_data, p = data_begin; ; n -= BUFSIZ, p += BUFSIZ)
+ if (n > BUFSIZ)
+ fwrite(p, BUFSIZ, 1, save);
+ else if (n > 0) {
+ fwrite(p, 1, n, save);
+ break;
+ } else
+ break;
+
+ fseek(original, original_data, 1);
+
+ filecpy(save, original, header.a_syms+header.a_trsize+header.a_drsize);
+ fread(&stsize, sizeof(stsize), 1, original);
+ fwrite(&stsize, sizeof(stsize), 1, save);
+ filecpy(save, original, stsize - sizeof(stsize));
+
+ fclose(original);
+ fclose(save);
+}