1 /* Copyright (C) 1985, 1986, 1987, 1988, 1992, 1993, 1994
2 Free Software Foundation, Inc.
4 This file is part of XEmacs.
6 XEmacs is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by the
8 Free Software Foundation; either version 2, or (at your option) any
11 XEmacs is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 You should have received a copy of the GNU General Public License
17 along with XEmacs; see the file COPYING. If not, write to
18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
21 /* Synched up with: FSF 19.31. */
24 * unexec.c - Convert a running program into an a.out file.
26 * Author: Spencer W. Thomas
27 * Computer Science Dept.
29 * Date: Tue Mar 2 1982
30 * Modified heavily since then.
33 * unexec (new_name, a_name, data_start, bss_start, entry_address)
34 * char *new_name, *a_name;
35 * unsigned data_start, bss_start, entry_address;
37 * Takes a snapshot of the program and makes an a.out format file in the
38 * file named by the string argument new_name.
39 * If a_name is non-NULL, the symbol table will be taken from the given file.
40 * On some machines, an existing a_name file is required.
42 * The boundaries within the a.out file may be adjusted with the data_start
43 * and bss_start arguments. Either or both may be given as 0 for defaults.
45 * Data_start gives the boundary between the text segment and the data
46 * segment of the program. The text segment can contain shared, read-only
47 * program code and literal data, while the data segment is always unshared
48 * and unprotected. Data_start gives the lowest unprotected address.
49 * The value you specify may be rounded down to a suitable boundary
50 * as required by the machine you are using.
52 * Specifying zero for data_start means the boundary between text and data
53 * should not be the same as when the program was loaded.
54 * If NO_REMAP is defined, the argument data_start is ignored and the
55 * segment boundaries are never changed.
57 * Bss_start indicates how much of the data segment is to be saved in the
58 * a.out file and restored when the program is executed. It gives the lowest
59 * unsaved address, and is rounded up to a page boundary. The default when 0
60 * is given assumes that the entire data segment is to be stored, including
61 * the previous data and bss as well as any additional storage allocated with
64 * The new file is set up to start at entry_address.
66 * If you make improvements I'd like to get them too.
67 * harpo!utah-cs!thomas, thomas@Utah-20
71 /* Modified to support SysVr3 shared libraries by James Van Artsdalen
72 * of Dell Computer Corporation. james@bigtex.cactus.org.
75 /* There are several compilation parameters affecting unexec:
79 Define this if your system uses COFF for executables.
83 Define this if you are using the GNU coff encapsulated a.out format.
84 This is closer to a.out than COFF. You should *not* define COFF if
85 you define COFF_ENCAPSULATE
87 Otherwise we assume you use Berkeley format.
91 Define this if you do not want to try to save Emacs's pure data areas
92 as part of the text segment.
94 Saving them as text is good because it allows users to share more.
96 However, on machines that locate the text area far from the data area,
97 the boundary cannot feasibly be moved. Such machines require
100 Also, remapping can cause trouble with the built-in startup routine
101 /lib/crt0.o, which defines `environ' as an initialized variable.
102 Dumping `environ' as pure does not work! So, to use remapping,
103 you must write a startup routine for your machine in Emacs's crt0.c.
104 If NO_REMAP is defined, Emacs uses the system's crt0.o.
108 Some machines that use COFF executables require that each section
109 start on a certain boundary *in the COFF file*. Such machines should
110 define SECTION_ALIGNMENT to a mask of the low-order bits that must be
111 zero on such a boundary. This mask is used to control padding between
112 segments in the COFF file.
114 If SECTION_ALIGNMENT is not defined, the segments are written
115 consecutively with no attempt at alignment. This is right for
120 Some machines require that the beginnings and ends of segments
121 *in core* be on certain boundaries. For most machines, a page
122 boundary is sufficient. That is the default. When a larger
123 boundary is needed, define SEGMENT_MASK to a mask of
124 the bits that must be zero on such a boundary.
128 Some machines count the a.out header as part of the size of the text
129 segment (a_text); they may actually load the header into core as the
130 first data in the text segment. Some have additional padding between
131 the header and the real text of the program that is counted in a_text.
133 For these machines, define A_TEXT_OFFSET(HDR) to examine the header
134 structure HDR and return the number of bytes to add to `a_text'
135 before writing it (above and beyond the number of bytes of actual
136 program text). HDR's standard fields are already correct, except that
137 this adjustment to the `a_text' field has not yet been made;
138 thus, the amount of offset can depend on the data in the file.
142 If defined, this macro specifies the number of bytes to seek into the
143 a.out file before starting to write the text segment.
147 For machines using COFF, this macro, if defined, is a value stored
148 into the magic number field of the output file.
152 This macro can be used to generate statements to adjust or
153 initialize nonstandard fields in the file header
157 Macro to correct an int which is the bit pattern of a pointer to a byte
158 into an int which is the number of a byte.
160 This macro has a default definition which is usually right.
161 This default definition is a no-op on most machines (where a
162 pointer looks like an int) but not on all machines.
167 #define PERROR(arg) perror (arg); return -1
170 #define DONT_ENCAPSULATE /* we include lisp.h so we want to make sure we
171 don't get filename conversion. The caller
172 of unexec() is assumed to have done this
173 already (it's easier to do it this way than
174 to modify all the unexec modules to ensure
175 that all weirdo functions, such as
176 elf_write_modified_data(), have proper
177 filename conversion applied). */
179 #define PERROR(file) report_error (file, new)
182 #if __STDC__ || defined(STDC_HEADERS)
184 /* I don't know how correct this attempt to get more prototypes is... */
185 # if defined(sun) && defined(_POSIX_SOURCE)
186 # undef _POSIX_SOURCE
198 /* I don't understand this, but it's necessary to get some slots in struct exec
199 from /usr/include/sys/exec.h when running LCC in strict ANSI mode. We don't
200 need this in K&R mode...
202 #if defined(__lucid) && defined(__sparc) && !defined(sun)
206 #ifndef CANNOT_DUMP /* all rest of file! */
208 #ifdef COFF_ENCAPSULATE
209 int need_coff_header = 1;
210 #include <coff-encap/a.out.encap.h> /* The location might be a poor assumption */
213 #endif /* not COFF_ENCAPSULATE */
215 /* Define getpagesize if the system does not.
216 Note that this may depend on symbols defined in a.out.h. */
217 #include "getpagesize.h"
219 #ifndef makedev /* Try to detect types.h already loaded */
220 #include <sys/types.h>
223 #include <sys/stat.h>
226 #include <sys/file.h> /* Must be after sys/types.h for USG and BSD4_1*/
240 extern char *start_of_text (); /* Start of text */
242 extern void *start_of_data (); /* Start of initialized data */
245 static long block_copy_start; /* Old executable start point */
246 static struct filehdr f_hdr; /* File header */
247 static struct aouthdr f_ohdr; /* Optional file header (a.out) */
248 long bias; /* Bias to add for growth */
249 long lnnoptr; /* Pointer to line-number info within file */
250 #define SYMS_START block_copy_start
252 static long text_scnptr;
253 static long data_scnptr;
258 #ifndef __sys_stdtypes_h
259 #if !defined(_PTRDIFF_T) && !defined(_BSD_PTRDIFF_T_)
260 typedef long ptrdiff_t;
264 /* not sure where this for NetBSD should really go
265 and it probably applies to other systems */
266 #if !defined(__NetBSD__) && !defined(__bsdi__) && !defined(__OpenBSD__)
267 extern void *sbrk (ptrdiff_t);
269 extern char *sbrk ();
270 #endif /* __NetBSD__ or __OpenBSD__ */
273 extern void *sbrk ();
276 #define SYMS_START ((long) N_SYMOFF (ohdr))
278 /* Some machines override the structure name for an a.out header. */
279 #ifndef EXEC_HDR_TYPE
280 #define EXEC_HDR_TYPE struct exec
285 #define MY_ID HP9000S200_ID
289 #endif /* no HP9000S200_ID */
290 static MAGIC OLDMAGIC = {MY_ID, SHARE_MAGIC};
291 static MAGIC NEWMAGIC = {MY_ID, DEMAND_MAGIC};
292 #define N_TXTOFF(x) TEXT_OFFSET(x)
293 #define N_SYMOFF(x) LESYM_OFFSET(x)
294 static EXEC_HDR_TYPE hdr, ohdr;
298 #if defined (USG) && !defined (IBMAIX) && !defined (IRIS) && !defined (COFF_ENCAPSULATE) && !defined (LINUX)
299 static struct bhdr hdr, ohdr;
300 #define a_magic fmagic
305 #define a_trsize rtsize
306 #define a_drsize rdsize
307 #define a_entry entry
308 #define N_BADMAG(x) \
309 (((x).fmagic)!=OMAGIC && ((x).fmagic)!=NMAGIC &&\
310 ((x).fmagic)!=FMAGIC && ((x).fmagic)!=IMAGIC)
311 #define NEWMAGIC FMAGIC
312 #else /* IRIS or IBMAIX or not USG */
313 static EXEC_HDR_TYPE hdr, ohdr;
314 #define NEWMAGIC ZMAGIC
315 #endif /* IRIS or IBMAIX not USG */
316 #endif /* not HPUX */
318 static int unexec_text_start;
319 static int unexec_data_start;
321 #ifdef COFF_ENCAPSULATE
322 /* coffheader is defined in the GNU a.out.encap.h file. */
323 struct coffheader coffheader;
326 #endif /* not COFF */
330 /* Correct an int which is the bit pattern of a pointer to a byte
331 into an int which is the number of a byte.
332 This is a no-op on ordinary machines, but not on all. */
334 #ifndef ADDR_CORRECT /* Let m-*.h files override this definition */
335 #define ADDR_CORRECT(x) ((char *)(x) - (char*)0)
343 report_error (const char *file, int fd)
347 report_file_error ("Cannot unexec",
348 Fcons (build_ext_string (file, Qfile_name), Qnil));
352 #define ERROR0(msg) report_error_1 (new, msg, 0, 0); return -1
353 #define ERROR1(msg,x) report_error_1 (new, msg, x, 0); return -1
354 #define ERROR2(msg,x,y) report_error_1 (new, msg, x, y); return -1
357 report_error_1 (fd, msg, a1, a2)
366 fprintf (stderr, msg, a1, a2);
367 fprintf (stderr, "\n");
371 static int make_hdr (int new, int a_out, unsigned data_start,
372 unsigned bss_start, unsigned entry_address,
373 char *a_name, char *new_name);
374 static int copy_text_and_data (int new, int a_out);
375 static int copy_sym (int new, int a_out, char *a_name, char *new_name);
376 static void mark_x (char *name);
378 /* ****************************************************************
384 unexec (new_name, a_name, data_start, bss_start, entry_address)
385 char *new_name, *a_name;
386 unsigned data_start, bss_start, entry_address;
390 if (a_name && (a_out = open (a_name, O_RDONLY)) < 0)
394 if ((new = creat (new_name, 0666)) < 0)
399 if (make_hdr (new, a_out, data_start, bss_start, entry_address, a_name, new_name) < 0
400 || copy_text_and_data (new, a_out) < 0
401 || copy_sym (new, a_out, a_name, new_name) < 0
403 #ifndef COFF_BSD_SYMBOLS
404 || adjust_lnnoptrs (new, a_out, new_name) < 0
410 /* unlink (new_name); / * Failed, unlink new a.out */
421 /* ****************************************************************
424 * Make the header in the new a.out from the header in core.
425 * Modify the text and data sizes.
428 make_hdr (int new, int a_out, unsigned data_start, unsigned bss_start,
429 unsigned entry_address, char *a_name, char *new_name)
432 auto struct scnhdr f_thdr; /* Text section header */
433 auto struct scnhdr f_dhdr; /* Data section header */
434 auto struct scnhdr f_bhdr; /* Bss section header */
435 auto struct scnhdr scntemp; /* Temporary section header */
438 #ifdef USG_SHARED_LIBRARIES
439 extern unsigned int bss_end;
441 unsigned int bss_end;
444 pagemask = getpagesize () - 1;
446 /* Adjust text/data boundary. */
448 data_start = (int) start_of_data ();
449 #else /* not NO_REMAP */
451 data_start = (int) start_of_data ();
452 #endif /* not NO_REMAP */
453 data_start = ADDR_CORRECT (data_start);
456 data_start = data_start & ~SEGMENT_MASK; /* (Down) to segment boundary. */
458 data_start = data_start & ~pagemask; /* (Down) to page boundary. */
461 bss_end = ADDR_CORRECT (sbrk (0)) + pagemask;
462 bss_end &= ~ pagemask;
464 /* Adjust data/bss boundary. */
467 bss_start = (ADDR_CORRECT (bss_start) + pagemask);
468 /* (Up) to page bdry. */
469 bss_start &= ~ pagemask;
470 if (bss_start > bss_end)
472 ERROR1 ("unexec: Specified bss_start (%u) is past end of program",
479 if (data_start > bss_start) /* Can't have negative data size. */
481 ERROR2 ("unexec: data_start (%u) can't be greater than bss_start (%u)",
482 data_start, bss_start);
486 /* Salvage as much info from the existing file as possible */
489 if (read (a_out, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr))
493 block_copy_start += sizeof (f_hdr);
494 if (f_hdr.f_opthdr > 0)
496 if (read (a_out, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr))
500 block_copy_start += sizeof (f_ohdr);
502 /* Loop through section headers, copying them in */
503 lseek (a_out, sizeof (f_hdr) + f_hdr.f_opthdr, 0);
504 for (scns = f_hdr.f_nscns; scns > 0; scns--) {
505 if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp))
509 if (scntemp.s_scnptr > 0L)
511 if (block_copy_start < scntemp.s_scnptr + scntemp.s_size)
512 block_copy_start = scntemp.s_scnptr + scntemp.s_size;
514 if (strcmp (scntemp.s_name, ".text") == 0)
518 else if (strcmp (scntemp.s_name, ".data") == 0)
522 else if (strcmp (scntemp.s_name, ".bss") == 0)
530 ERROR0 ("can't build a COFF file from scratch yet");
533 /* Now we alter the contents of all the f_*hdr variables
534 to correspond to what we want to dump. */
536 #ifdef USG_SHARED_LIBRARIES
538 /* The amount of data we're adding to the file is distance from the
539 * end of the original .data space to the current end of the .data
543 bias = bss_start - (f_ohdr.data_start + f_dhdr.s_size);
547 f_hdr.f_flags |= (F_RELFLG | F_EXEC);
552 f_ohdr.magic = EXEC_MAGIC;
555 f_ohdr.text_start = (long) start_of_text ();
556 f_ohdr.tsize = data_start - f_ohdr.text_start;
557 f_ohdr.data_start = data_start;
558 #endif /* NO_REMAP */
559 f_ohdr.dsize = bss_start - f_ohdr.data_start;
560 f_ohdr.bsize = bss_end - bss_start;
561 #ifndef KEEP_OLD_TEXT_SCNPTR
562 /* On some machines, the old values are right.
563 ??? Maybe on all machines with NO_REMAP. */
564 f_thdr.s_size = f_ohdr.tsize;
565 f_thdr.s_scnptr = sizeof (f_hdr) + sizeof (f_ohdr);
566 f_thdr.s_scnptr += (f_hdr.f_nscns) * (sizeof (f_thdr));
567 #endif /* KEEP_OLD_TEXT_SCNPTR */
568 #ifdef ADJUST_TEXT_SCNHDR_SIZE
569 /* On some machines, `text size' includes all headers. */
570 f_thdr.s_size -= f_thdr.s_scnptr;
571 #endif /* ADJUST_TEST_SCNHDR_SIZE */
572 lnnoptr = f_thdr.s_lnnoptr;
573 #ifdef SECTION_ALIGNMENT
574 /* Some systems require special alignment
575 of the sections in the file itself. */
577 = (f_thdr.s_scnptr + SECTION_ALIGNMENT) & ~SECTION_ALIGNMENT;
578 #endif /* SECTION_ALIGNMENT */
580 f_thdr.s_scnptr = 0xd0;
582 text_scnptr = f_thdr.s_scnptr;
583 #ifdef ADJUST_TEXTBASE
584 text_scnptr = sizeof (f_hdr) + sizeof (f_ohdr) + (f_hdr.f_nscns) * (sizeof (f_thdr));
586 #ifndef KEEP_OLD_PADDR
587 f_dhdr.s_paddr = f_ohdr.data_start;
588 #endif /* KEEP_OLD_PADDR */
589 f_dhdr.s_vaddr = f_ohdr.data_start;
590 f_dhdr.s_size = f_ohdr.dsize;
591 f_dhdr.s_scnptr = f_thdr.s_scnptr + f_thdr.s_size;
592 #ifdef SECTION_ALIGNMENT
593 /* Some systems require special alignment
594 of the sections in the file itself. */
596 = (f_dhdr.s_scnptr + SECTION_ALIGNMENT) & ~SECTION_ALIGNMENT;
597 #endif /* SECTION_ALIGNMENT */
598 #ifdef DATA_SECTION_ALIGNMENT
599 /* Some systems require special alignment
600 of the data section only. */
602 = (f_dhdr.s_scnptr + DATA_SECTION_ALIGNMENT) & ~DATA_SECTION_ALIGNMENT;
603 #endif /* DATA_SECTION_ALIGNMENT */
604 data_scnptr = f_dhdr.s_scnptr;
605 #ifndef KEEP_OLD_PADDR
606 f_bhdr.s_paddr = f_ohdr.data_start + f_ohdr.dsize;
607 #endif /* KEEP_OLD_PADDR */
608 f_bhdr.s_vaddr = f_ohdr.data_start + f_ohdr.dsize;
609 f_bhdr.s_size = f_ohdr.bsize;
610 f_bhdr.s_scnptr = 0L;
611 #ifndef USG_SHARED_LIBRARIES
612 bias = f_dhdr.s_scnptr + f_dhdr.s_size - block_copy_start;
615 if (f_hdr.f_symptr > 0L)
617 f_hdr.f_symptr += bias;
620 if (f_thdr.s_lnnoptr > 0L)
622 f_thdr.s_lnnoptr += bias;
625 #ifdef ADJUST_EXEC_HEADER
627 #endif /* ADJUST_EXEC_HEADER */
629 if (write (new, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr))
634 if (write (new, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr))
639 #ifndef USG_SHARED_LIBRARIES
641 if (write (new, &f_thdr, sizeof (f_thdr)) != sizeof (f_thdr))
646 if (write (new, &f_dhdr, sizeof (f_dhdr)) != sizeof (f_dhdr))
651 if (write (new, &f_bhdr, sizeof (f_bhdr)) != sizeof (f_bhdr))
656 #else /* USG_SHARED_LIBRARIES */
658 /* The purpose of this code is to write out the new file's section
661 * Scan through the original file's sections. If the encountered
662 * section is one we know (.text, .data or .bss), write out the
663 * correct header. If it is a section we do not know (such as
664 * .lib), adjust the address of where the section data is in the
665 * file, and write out the header.
667 * If any section precedes .text or .data in the file, this code
668 * will not adjust the file pointer for that section correctly.
671 /* This used to use sizeof (f_ohdr) instead of .f_opthdr.
672 .f_opthdr is said to be right when there is no optional header. */
673 lseek (a_out, sizeof (f_hdr) + f_hdr.f_opthdr, 0);
675 for (scns = f_hdr.f_nscns; scns > 0; scns--)
677 if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp))
680 if (!strcmp (scntemp.s_name, f_thdr.s_name)) /* .text */
682 if (write (new, &f_thdr, sizeof (f_thdr)) != sizeof (f_thdr))
685 else if (!strcmp (scntemp.s_name, f_dhdr.s_name)) /* .data */
687 if (write (new, &f_dhdr, sizeof (f_dhdr)) != sizeof (f_dhdr))
690 else if (!strcmp (scntemp.s_name, f_bhdr.s_name)) /* .bss */
692 if (write (new, &f_bhdr, sizeof (f_bhdr)) != sizeof (f_bhdr))
697 if (scntemp.s_scnptr)
698 scntemp.s_scnptr += bias;
699 if (write (new, &scntemp, sizeof (scntemp)) != sizeof (scntemp))
703 #endif /* USG_SHARED_LIBRARIES */
707 #else /* if not COFF */
709 /* Get symbol table info from header of a.out file if given one. */
712 #ifdef COFF_ENCAPSULATE
713 if (read (a_out, &coffheader, sizeof coffheader) != sizeof coffheader)
717 if (coffheader.f_magic != COFF_MAGIC)
719 ERROR1("%s doesn't have legal coff magic number\n", a_name);
722 if (read (a_out, (char *) &ohdr, sizeof hdr) != sizeof hdr)
729 ERROR1 ("invalid magic number in %s", a_name);
735 #ifdef COFF_ENCAPSULATE
736 /* We probably could without too much trouble. The code is in gld
737 * but I don't have that much time or incentive.
739 ERROR0 ("can't build a COFF file from scratch yet");
741 memset ((void *)&hdr, 0, sizeof hdr);
745 unexec_text_start = (long) start_of_text ();
746 unexec_data_start = data_start;
748 /* Machine-dependent fixup for header, or maybe for unexec_text_start */
749 #ifdef ADJUST_EXEC_HEADER
751 #endif /* ADJUST_EXEC_HEADER */
755 if (entry_address != 0)
756 hdr.a_entry = entry_address;
758 hdr.a_bss = bss_end - bss_start;
759 hdr.a_data = bss_start - data_start;
761 hdr.a_text = ohdr.a_text;
762 #else /* not NO_REMAP */
763 hdr.a_text = data_start - unexec_text_start;
766 hdr.a_text += A_TEXT_OFFSET (ohdr);
769 #endif /* not NO_REMAP */
771 #ifdef COFF_ENCAPSULATE
772 /* We are encapsulating BSD format within COFF format. */
774 struct coffscn *tp, *dp, *bp;
775 tp = &coffheader.scns[0];
776 dp = &coffheader.scns[1];
777 bp = &coffheader.scns[2];
778 tp->s_size = hdr.a_text + sizeof(struct exec);
779 dp->s_paddr = data_start;
780 dp->s_vaddr = data_start;
781 dp->s_size = hdr.a_data;
782 bp->s_paddr = dp->s_vaddr + dp->s_size;
783 bp->s_vaddr = bp->s_paddr;
784 bp->s_size = hdr.a_bss;
785 coffheader.tsize = tp->s_size;
786 coffheader.dsize = dp->s_size;
787 coffheader.bsize = bp->s_size;
788 coffheader.text_start = tp->s_vaddr;
789 coffheader.data_start = dp->s_vaddr;
791 if (write (new, &coffheader, sizeof coffheader) != sizeof coffheader)
795 #endif /* COFF_ENCAPSULATE */
797 if (write (new, (char *) &hdr, sizeof hdr) != sizeof hdr)
802 #if 0 /* This #ifndef caused a bug on Linux when using QMAGIC. */
803 /* This adjustment was done above only #ifndef NO_REMAP,
804 so only undo it now #ifndef NO_REMAP. */
805 /* #ifndef NO_REMAP */
808 hdr.a_text -= A_TEXT_OFFSET (ohdr);
813 #endif /* not COFF */
816 static void write_segment (int, char *, char *);
818 /* ****************************************************************
821 * Copy the text and data segments from memory to the new a.out
824 copy_text_and_data (int new, int a_out)
831 #ifdef USG_SHARED_LIBRARIES
834 struct scnhdr scntemp; /* Temporary section header */
836 /* The purpose of this code is to write out the new file's section
839 * Step through the section table. If we know the section (.text,
840 * .data) do the appropriate thing. Otherwise, if the section has
841 * no allocated space in the file (.bss), do nothing. Otherwise,
842 * the section has space allocated in the file, and is not a section
843 * we know. So just copy it.
846 lseek (a_out, sizeof (struct filehdr) + sizeof (struct aouthdr), 0);
848 for (scns = f_hdr.f_nscns; scns > 0; scns--)
850 if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp))
853 if (!strcmp (scntemp.s_name, ".text"))
855 lseek (new, (long) text_scnptr, 0);
856 ptr = (char *) f_ohdr.text_start;
857 end = ptr + f_ohdr.tsize;
858 write_segment (new, ptr, end);
860 else if (!strcmp (scntemp.s_name, ".data"))
862 lseek (new, (long) data_scnptr, 0);
863 ptr = (char *) f_ohdr.data_start;
864 end = ptr + f_ohdr.dsize;
865 write_segment (new, ptr, end);
867 else if (!scntemp.s_scnptr)
868 ; /* do nothing - no data for this section */
873 long old_a_out_ptr = lseek (a_out, 0, 1);
875 lseek (a_out, scntemp.s_scnptr, 0);
876 for (size = scntemp.s_size; size > 0; size -= sizeof (page))
878 n = size > sizeof (page) ? sizeof (page) : size;
879 if (read (a_out, page, n) != n || write (new, page, n) != n)
882 lseek (a_out, old_a_out_ptr, 0);
886 #else /* COFF, but not USG_SHARED_LIBRARIES */
888 lseek (new, (long) text_scnptr, 0);
889 ptr = (char *) f_ohdr.text_start;
890 #ifdef HEADER_INCL_IN_TEXT
891 /* For Gould UTX/32, text starts after headers */
892 ptr = (char *) (ptr + text_scnptr);
893 #endif /* HEADER_INCL_IN_TEXT */
894 end = ptr + f_ohdr.tsize;
895 write_segment (new, ptr, end);
897 lseek (new, (long) data_scnptr, 0);
898 ptr = (char *) f_ohdr.data_start;
899 end = ptr + f_ohdr.dsize;
900 write_segment (new, ptr, end);
902 #endif /* USG_SHARED_LIBRARIES */
904 #else /* if not COFF */
906 /* Some machines count the header as part of the text segment.
907 That is to say, the header appears in core
908 just before the address that start_of_text returns.
909 For them, N_TXTOFF is the place where the header goes.
910 We must adjust the seek to the place after the header.
911 Note that at this point hdr.a_text does *not* count
912 the extra A_TEXT_OFFSET bytes, only the actual bytes of code. */
915 lseek (new, (long) A_TEXT_SEEK (hdr), 0);
917 lseek (new, (long) N_TXTOFF (hdr), 0);
918 #endif /* no A_TEXT_SEEK */
922 /* Acorn's RISC-iX has a wacky way of initializing the position of the heap.
923 * There is a little table in crt0.o that is filled at link time with
924 * the min and current brk positions, among other things. When start
925 * runs, it copies the table to where these parameters live during
926 * execution. This data is in text space, so it cannot be modified here
927 * before saving the executable, so the data is written manually. In
928 * addition, the table does not have a label, and the nearest accessible
929 * label (mcount) is not prefixed with a '_', thus making it inaccessible
930 * from within C programs. To overcome this, emacs's executable is passed
931 * through the command 'nm %s | fgrep mcount' into a pipe, and the
932 * resultant output is then used to find the address of 'mcount'. As far as
933 * is possible to determine, in RISC-iX releases prior to 1.2, the negative
934 * offset of the table from mcount is 0x2c, whereas from 1.2 onwards it is
935 * 0x30. bss_end has been rounded up to page boundary. This solution is
936 * based on suggestions made by Kevin Welton and Steve Hunt of Acorn, and
937 * avoids the need for a custom version of crt0.o for emacs which has its
938 * table in data space.
944 char address_text[32];
949 int mcount_address, mcount_offset, count;
950 extern char *_execname;
953 /* The use of _execname is incompatible with RISCiX 1.1 */
954 sprintf (command, "nm %s | fgrep mcount", _execname);
956 if ( (pfile = popen(command, "r")) == NULL)
958 sprintf (errbuf, "Could not open pipe");
963 while ( ((c=getc(pfile)) != EOF) && (c != ' ') && (count < 31))
964 address_text[count++]=c;
965 address_text[count]=0;
967 if ((count == 0) || pclose(pfile) != NULL)
969 sprintf (errbuf, "Failed to execute the command '%s'\n", command);
973 sscanf(address_text, "%x", &mcount_address);
974 ptr = (char *) unexec_text_start;
975 mcount_offset = (char *)mcount_address - ptr;
978 #define EDATA_OFFSET 0x2c
980 #define EDATA_OFFSET 0x30
983 end = ptr + mcount_offset - EDATA_OFFSET;
985 write_segment (new, ptr, end);
987 proforma[0] = bss_end; /* becomes _edata */
988 proforma[1] = bss_end; /* becomes _end */
989 proforma[2] = bss_end; /* becomes _minbrk */
990 proforma[3] = bss_end; /* becomes _curbrk */
992 write (new, proforma, 16);
996 end = temp_ptr + hdr.a_text;
998 write_segment (new, ptr, end);
1002 ptr = (char *) unexec_text_start;
1003 end = ptr + hdr.a_text;
1004 write_segment (new, ptr, end);
1007 ptr = (char *) unexec_data_start;
1008 end = ptr + hdr.a_data;
1009 /* This lseek is certainly incorrect when A_TEXT_OFFSET
1010 and I believe it is a no-op otherwise.
1011 Let's see if its absence ever fails. */
1012 /* lseek (new, (long) N_TXTOFF (hdr) + hdr.a_text, 0); */
1013 write_segment (new, ptr, end);
1015 #endif /* not COFF */
1021 write_segment (new, ptr, end)
1029 /* This is the normal amount to write at once.
1030 It is the size of block that NFS uses. */
1031 int writesize = 1 << 13;
1032 int pagesize = getpagesize ();
1033 char zeros[1 << 13];
1035 memset (zeros, 0, sizeof (zeros));
1037 for (i = 0; ptr < end;)
1039 /* Distance to next multiple of writesize. */
1040 nwrite = (((int) ptr + writesize) & -writesize) - (int) ptr;
1041 /* But not beyond specified end. */
1042 if (nwrite > end - ptr) nwrite = end - ptr;
1043 ret = write (new, ptr, nwrite);
1044 /* If write gets a page fault, it means we reached
1045 a gap between the old text segment and the old data segment.
1046 This gap has probably been remapped into part of the text segment.
1047 So write zeros for it. */
1054 /* Write only a page of zeros at once,
1055 so that we don't overshoot the start
1056 of the valid memory in the old data segment. */
1057 if (nwrite > pagesize)
1059 write (new, zeros, nwrite);
1061 #if 0 /* Now that we have can ask `write' to write more than a page,
1062 it is legit for write do less than the whole amount specified. */
1063 else if (nwrite != ret)
1066 "unexec write failure: addr 0x%lx, fileno %d, size 0x%x, wrote 0x%x, errno %d",
1067 (unsigned long) ptr, new, nwrite, ret, errno);
1076 /* ****************************************************************
1079 * Copy the relocation information and symbol table from the a.out to the new
1082 copy_sym (int new, int a_out, char *a_name, char *new_name)
1091 if (SYMS_START == 0L)
1096 if (lnnoptr) /* if there is line number info */
1097 lseek (a_out, lnnoptr, 0); /* start copying from there */
1100 lseek (a_out, SYMS_START, 0); /* Position a.out to symtab. */
1102 while ((n = read (a_out, page, sizeof page)) > 0)
1104 if (write (new, page, n) != n)
1116 /* ****************************************************************
1119 * After successfully building the new a.out, mark it executable
1126 int new = 0; /* for PERROR */
1130 if (stat (name, &sbuf) == -1)
1134 sbuf.st_mode |= 0111 & ~um;
1135 if (chmod (name, sbuf.st_mode) == -1)
1140 #ifndef COFF_BSD_SYMBOLS
1143 * If the COFF file contains a symbol table and a line number section,
1144 * then any auxiliary entries that have values for x_lnnoptr must
1145 * be adjusted by the amount that the line number section has moved
1146 * in the file (bias computed in make_hdr). The #@$%&* designers of
1147 * the auxiliary entry structures used the absolute file offsets for
1148 * the line number entry rather than an offset from the start of the
1149 * line number section!
1151 * When I figure out how to scan through the symbol table and pick out
1152 * the auxiliary entries that need adjustment, this routine will
1153 * be fixed. As it is now, all such entries are wrong and sdb
1154 * will complain. Fred Fish, UniSoft Systems Inc.
1157 /* This function is probably very slow. Instead of reopening the new
1158 file for input and output it should copy from the old to the new
1159 using the two descriptors already open (WRITEDESC and READDESC).
1160 Instead of reading one small structure at a time it should use
1161 a reasonable size buffer. But I don't have time to work on such
1162 things, so I am installing it as submitted to me. -- RMS. */
1165 adjust_lnnoptrs (writedesc, readdesc, new_name)
1172 #if defined (amdahl_uts) || defined (pfa)
1176 struct syment symentry;
1177 union auxent auxentry;
1180 if (!lnnoptr || !f_hdr.f_symptr)
1183 if ((new = open (new_name, O_RDWR)) < 0)
1189 lseek (new, f_hdr.f_symptr, 0);
1190 for (nsyms = 0; nsyms < f_hdr.f_nsyms; nsyms++)
1192 read (new, &symentry, SYMESZ);
1193 if (symentry.n_numaux)
1195 read (new, &auxentry, AUXESZ);
1197 if (ISFCN (symentry.n_type) || symentry.n_type == 0x2400)
1199 auxentry.x_sym.x_fcnary.x_fcn.x_lnnoptr += bias;
1200 lseek (new, -AUXESZ, 1);
1201 write (new, &auxentry, AUXESZ);
1209 #endif /* COFF_BSD_SYMBOLS */
1213 #endif /* not CANNOT_DUMP */