* Mike Sperber <sperber@informatik.uni-tuebingen.de>
*
* Synopsis:
- * unexec (new_name, a_name, data_start, bss_start, entry_address)
- * char *new_name, *a_name;
- * unsigned data_start, bss_start, entry_address;
+ * unexec (const char *new_name, const *old_name);
*
* Takes a snapshot of the program and makes an a.out format file in the
* file named by the string argument new_name.
* If a_name is non-NULL, the symbol table will be taken from the given file.
* On some machines, an existing a_name file is required.
*
- * data_start and entry_address are ignored.
- *
- * bss_start indicates how much of the data segment is to be saved in the
- * a.out file and restored when the program is executed. It gives the lowest
- * unsaved address, and is rounded up to a page boundary. The default when 0
- * is given assumes that the entire data segment is to be stored, including
- * the previous data and bss as well as any additional storage allocated with
- * sbrk(2).
- *
*/
-#ifndef emacs
-#define PERROR(arg) perror (arg); return -1
-#else
#include <config.h>
#define PERROR(file) report_error (file, new)
-#endif
-
#include <a.out.h>
/* Define getpagesize () if the system does not.
Note that this may depend on symbols defined in a.out.h
#include <unistd.h>
#include <fcntl.h>
-extern char *start_of_text (void); /* Start of text */
+char *start_of_text (void); /* Start of text */
extern char *start_of_data (void); /* Start of initialized data */
extern int _data;
static int pagemask;
-#ifdef emacs
#include <setjmp.h>
#include "lisp.h"
close (fd);
report_file_error ("Cannot unexec", Fcons (build_string (file), Qnil));
}
-#endif /* emacs */
#define ERROR0(msg) report_error_1 (new, msg, 0, 0); return -1
#define ERROR1(msg,x) report_error_1 (new, msg, x, 0); return -1
report_error_1 (int fd, char *msg, int a1, int a2)
{
close (fd);
-#ifdef emacs
error (msg, a1, a2);
-#else
- fprintf (stderr, msg, a1, a2);
- fprintf (stderr, "\n");
-#endif
}
static int make_hdr (int, int, unsigned, unsigned, unsigned, char *, char *);
*
* driving logic.
*/
-int unexec (char *new_name, char *a_name,
- unsigned data_start,
- unsigned bss_start,
- unsigned entry_address)
+int unexec (const char *new_name, const char *a_name)
{
int new = -1, a_out = -1;
PERROR (new_name);
}
if (make_hdr (new, a_out,
- data_start, bss_start,
- entry_address,
a_name, new_name) < 0
|| copy_text_and_data (new) < 0
|| copy_sym (new, a_out, a_name, new_name) < 0
*/
static int
make_hdr (int new, int a_out,
- unsigned data_start, unsigned bss_start,
- unsigned entry_address,
char *a_name, char *new_name)
{
int scns;
- unsigned int bss_end;
+ unsigned int bss_start;
+ unsigned int data_start;
struct scnhdr section[MAX_SECTIONS];
struct scnhdr * f_thdr; /* Text section header */
data_start = data_start & ~pagemask; /* (Down) to page boundary. */
- bss_end = ADDR_CORRECT (sbrk (0)) + pagemask;
- bss_end &= ~ pagemask;
- /* Adjust data/bss boundary. */
- if (bss_start != 0)
- {
- bss_start = (ADDR_CORRECT (bss_start) + pagemask);
- /* (Up) to page bdry. */
- bss_start &= ~ pagemask;
- if (bss_start > bss_end)
- {
- ERROR1 ("unexec: Specified bss_start (%u) is past end of program",
- bss_start);
- }
- }
- else
- bss_start = bss_end;
+ bss_start = ADDR_CORRECT (sbrk (0)) + pagemask;
+ bss_start &= ~ pagemask;
if (data_start > bss_start) /* Can't have negative data size. */
{
f_hdr.f_flags |= (F_RELFLG | F_EXEC);
f_ohdr.dsize = bss_start - f_ohdr.data_start;
- f_ohdr.bsize = bss_end - bss_start;
+ f_ohdr.bsize = 0;
f_dhdr->s_size = f_ohdr.dsize;
f_bhdr->s_size = f_ohdr.bsize;
{
int i, nwrite, ret;
char buf[80];
- extern int errno;
char zeros[UnexBlockSz];
for (i = 0; ptr < end;)
return 0;
}
+/*
+ * Return the address of the start of the text segment prior to
+ * doing an unexec. After unexec the return value is undefined.
+ * See crt0.c for further explanation and _start.
+ *
+ */
+
+char *
+start_of_text (void)
+{
+ return ((char *) 0x10000000);
+}
+
/* arch-tag: 0783857a-7c2d-456f-a426-58b722d69fd0
(do not change this comment) */