1 /* unexec for GNU Emacs on Cygwin32.
2 Copyright (C) 1994, 1998 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 the Free
18 Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
23 /* This is a complete rewrite, some code snarfed from unexnt.c and
24 unexec.c, Andy Piper (andy@xemacs.org) 13-1-98 */
35 #define DONT_ENCAPSULATE /* filenames are external in unex*.c */
38 #define PERROR(arg) perror(arg);exit(-1)
41 unexec (char *, char *, void *, void *, void *)
43 PERROR("cannot unexec() a.out.h not installed");
52 #define ALLOC_UNIT 0xFFFF
53 #define ALLOC_MASK ~((unsigned long)(ALLOC_UNIT))
54 #define ALIGN_ALLOC(addr) \
55 ((((unsigned long)addr) + ALLOC_UNIT) & ALLOC_MASK)
56 /* Note that all sections must be aligned on a 0x1000 boundary so
57 this is the minimum size that our dummy bss can be. */
59 #define BSS_PAD_SIZE 0x1000
61 #define BSS_PAD_SIZE 0
64 /* To prevent zero-initialized variables from being placed into the bss
65 section, use non-zero values to represent an uninitialized state. */
66 #define UNINIT_PTR ((void *) 0xF0A0F0A0)
67 #define UNINIT_LONG (0xF0A0F0A0L)
69 static void get_section_info (int a_out, char* a_name);
70 static void copy_executable_and_dump_data_section (int a_out, int a_new);
71 static void dup_file_area(int a_out, int a_new, long size);
73 static void write_int_to_bss(int a_out, int a_new, void* va, void* newval);
76 /* Cached info about the .data section in the executable. */
77 void* data_start_va = UNINIT_PTR;
78 unsigned long data_size = UNINIT_LONG;
80 /* Cached info about the .bss section in the executable. */
81 void* bss_start = UNINIT_PTR;
82 unsigned long bss_size = UNINIT_LONG;
83 int sections_reversed = 0;
86 SCNHDR f_data, f_bss, f_text, f_nextdata;
88 #define PERROR(arg) perror(arg);exit(-1)
89 #define CHECK_AOUT_POS(a) \
90 if (lseek(a_out, 0, SEEK_CUR) != a) \
92 printf("we are at %lx, should be at %lx\n", \
93 lseek(a_out, 0, SEEK_CUR), a); \
97 /* Dump out .data and .bss sections into a new executable. */
99 unexec (char *out_name, char *in_name, uintptr_t start_data,
100 uintptr_t d1, uintptr_t d2)
102 /* ugly nt hack - should be in lisp */
103 int a_new, a_out = -1;
104 char new_name[MAX_PATH], a_name[MAX_PATH];
107 /* Make sure that the input and output filenames have the
108 ".exe" extension...patch them up if they don't. */
109 strcpy (a_name, in_name);
110 ptr = a_name + strlen (a_name) - 4;
111 if (strcmp (ptr, ".exe"))
112 strcat (a_name, ".exe");
114 strcpy (new_name, out_name);
115 ptr = new_name + strlen (new_name) - 4;
116 if (strcmp (ptr, ".exe"))
117 strcat (new_name, ".exe");
119 /* We need to round off our heap to NT's allocation unit (64KB). */
120 /* round_heap (get_allocation_unit ()); */
122 if (a_name && (a_out = open (a_name, O_RDONLY | OPEN_BINARY)) < 0)
127 if ((a_new = open (new_name, O_WRONLY | O_TRUNC | O_CREAT | OPEN_BINARY,
133 /* Get the interesting section info, like start and size of .bss... */
134 get_section_info (a_out, a_name);
136 copy_executable_and_dump_data_section (a_out, a_new);
143 /* Flip through the executable and cache the info necessary for dumping. */
144 static void get_section_info (int a_out, char* a_name)
146 extern char my_ebss[];
147 /* From lastfile.c */
148 extern char my_edata[];
150 if (read (a_out, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr))
155 if (f_hdr.e_magic != DOSMAGIC)
157 PERROR("unknown exe header");
160 /* Check the NT header signature ... */
161 if (f_hdr.nt_signature != NT_SIGNATURE)
163 PERROR("invalid nt header");
166 /* Flip through the sections for .data and .bss ... */
167 if (f_hdr.f_opthdr > 0)
169 if (read (a_out, &f_ohdr, AOUTSZ) != AOUTSZ)
174 /* Loop through .data & .bss section headers, copying them in.
175 With newer lds these are reversed so we have to cope with both */
176 lseek (a_out, sizeof (f_hdr) + f_hdr.f_opthdr, 0);
178 if (read (a_out, &f_text, sizeof (f_text)) != sizeof (f_text)
180 strcmp (f_text.s_name, ".text"))
182 PERROR ("no .text section");
185 /* The .bss section. */
186 if (read (a_out, &f_bss, sizeof (f_bss)) != sizeof (f_bss)
188 (strcmp (f_bss.s_name, ".bss") && strcmp (f_bss.s_name, ".data")))
190 PERROR ("no .bss / .data section");
193 /* check for reversed .bss and .data */
194 if (!strcmp(f_bss.s_name, ".data"))
196 printf(".data and .bss reversed\n");
197 sections_reversed = 1;
198 memcpy(&f_data, &f_bss, sizeof(f_bss));
201 /* The .data section. */
202 if (!sections_reversed)
204 if (read (a_out, &f_data, sizeof (f_data)) != sizeof (f_data)
206 strcmp (f_data.s_name, ".data"))
208 PERROR ("no .data section");
213 if (read (a_out, &f_bss, sizeof (f_bss)) != sizeof (f_bss)
215 strcmp (f_bss.s_name, ".bss"))
217 PERROR ("no .bss section");
221 bss_start = (void *) ((char*)f_ohdr.ImageBase + f_bss.s_vaddr);
222 bss_size = (unsigned long)((char*)&my_ebss-(char*)bss_start);
224 /* must keep bss data that we want to be blank as blank */
225 printf("found bss - keeping %lx of %lx bytes\n", bss_size, f_ohdr.bsize);
227 /* The .data section. */
228 data_start_va = (void *) ((char*)f_ohdr.ImageBase + f_data.s_vaddr);
230 /* We want to only write Emacs data back to the executable,
231 not any of the library data (if library data is included,
232 then a dumped Emacs won't run on system versions other
233 than the one Emacs was dumped on). */
234 data_size = (unsigned long)my_edata - (unsigned long)data_start_va;
235 printf("found data - keeping %lx of %lx bytes\n", data_size, f_ohdr.dsize);
237 /* The following data section - often .idata */
238 if (read (a_out, &f_nextdata, sizeof (f_nextdata)) != sizeof (f_nextdata)
240 strcmp (&f_nextdata.s_name[2], "data"))
242 PERROR ("no other data section");
246 /* The dump routines. */
249 copy_executable_and_dump_data_section (int a_out, int a_new)
252 unsigned long new_data_size, new_bss_size,
253 bss_padding, file_sz_change, data_padding=0,
254 f_data_s_vaddr = f_data.s_vaddr,
255 f_data_s_scnptr = f_data.s_scnptr,
256 f_bss_s_vaddr = f_bss.s_vaddr,
257 f_nextdata_s_scnptr = f_nextdata.s_scnptr;
261 extern int static_heap_dumped;
263 /* calculate new sizes:
265 f_ohdr.dsize is the total initialized data size on disk which is
266 f_data.s_size + f_idata.s_size.
268 f_ohdr.data_start is the base addres of all data and so should
271 *.s_vaddr is the virtual address of the start of the section
272 *normalized from f_ohdr.ImageBase.
274 *.s_paddr appears to be the number of bytes in the section
275 *actually used (whereas *.s_size is aligned).
277 bsize is now 0 since subsumed into .data
278 dsize is dsize + (f_data.s_vaddr - f_bss.s_vaddr)
279 f_data.s_vaddr is f_bss.s_vaddr
280 f_data.s_size is new dsize maybe.
281 what about s_paddr & s_scnptr? */
283 /* this is the amount the file increases in size */
284 if (!sections_reversed)
286 new_bss_size = f_data.s_vaddr - f_bss.s_vaddr;
291 new_bss_size = f_nextdata.s_vaddr - f_bss.s_vaddr;
292 data_padding = (f_bss.s_vaddr - f_data.s_vaddr) - f_data.s_size;
295 if ((new_bss_size - bss_size) < BSS_PAD_SIZE)
297 PERROR (".bss free space too small");
300 file_sz_change=(new_bss_size + data_padding) - BSS_PAD_SIZE;
301 new_data_size=f_ohdr.dsize + file_sz_change;
303 if (!sections_reversed)
305 f_data.s_vaddr = f_bss.s_vaddr;
307 f_data.s_paddr += file_sz_change;
309 if (f_data.s_size + f_nextdata.s_size != f_ohdr.dsize)
311 printf("section size doesn't tally with dsize %lx != %lx\n",
312 f_data.s_size + f_nextdata.s_size, f_ohdr.dsize);
315 f_data.s_size += file_sz_change;
316 lseek (a_new, 0, SEEK_SET);
317 /* write file header */
318 f_hdr.f_symptr += file_sz_change;
323 printf("writing file header\n");
324 if (write(a_new, &f_hdr, sizeof(f_hdr)) != sizeof(f_hdr))
326 PERROR("failed to write file header");
328 /* write optional header fixing dsize & bsize*/
329 printf("writing optional header\n");
330 printf("new data size is %lx, >= %lx\n", new_data_size,
331 f_ohdr.dsize + f_ohdr.bsize);
332 if (new_data_size < f_ohdr.dsize + f_ohdr.bsize )
334 PERROR("new data size is < approx");
336 f_ohdr.dsize=new_data_size;
337 f_ohdr.bsize=BSS_PAD_SIZE;
338 if (write(a_new, &f_ohdr, sizeof(f_ohdr)) != sizeof(f_ohdr))
340 PERROR("failed to write optional header");
342 /* write text as is */
343 printf("writing text header (unchanged)\n");
345 if (write(a_new, &f_text, sizeof(f_text)) != sizeof(f_text))
347 PERROR("failed to write text header");
350 /* Write small bss section. */
351 if (!sections_reversed)
353 f_bss.s_size = BSS_PAD_SIZE;
354 f_bss.s_paddr = BSS_PAD_SIZE;
355 f_bss.s_vaddr = f_data.s_vaddr - BSS_PAD_SIZE;
356 if (write(a_new, &f_bss, sizeof(f_bss)) != sizeof(f_bss))
358 PERROR("failed to write bss header");
362 /* write new data header */
363 printf("writing .data header\n");
365 if (write(a_new, &f_data, sizeof(f_data)) != sizeof(f_data))
367 PERROR("failed to write data header");
370 /* Write small bss section. */
371 if (sections_reversed)
373 f_bss.s_size = BSS_PAD_SIZE;
374 f_bss.s_paddr = BSS_PAD_SIZE;
375 f_bss.s_vaddr = f_nextdata.s_vaddr - BSS_PAD_SIZE;
376 if (write(a_new, &f_bss, sizeof(f_bss)) != sizeof(f_bss))
378 PERROR("failed to write bss header");
382 printf("writing following data header\n");
383 f_nextdata.s_scnptr += file_sz_change;
384 if (f_nextdata.s_lnnoptr != 0) f_nextdata.s_lnnoptr += file_sz_change;
385 if (f_nextdata.s_relptr != 0) f_nextdata.s_relptr += file_sz_change;
386 if (write(a_new, &f_nextdata, sizeof(f_nextdata)) != sizeof(f_nextdata))
388 PERROR("failed to write nextdata header");
391 /* copy other section headers adjusting the file offset */
392 for (i=0; i<(f_hdr.f_nscns-3); i++)
394 if (read (a_out, §ion, sizeof (section)) != sizeof (section))
396 PERROR ("no .data section");
399 section.s_scnptr += file_sz_change;
400 if (section.s_lnnoptr != 0) section.s_lnnoptr += file_sz_change;
401 if (section.s_relptr != 0) section.s_relptr += file_sz_change;
403 if (write(a_new, §ion, sizeof(section)) != sizeof(section))
405 PERROR("failed to write data header");
409 /* dump bss to maintain offsets */
410 memset(&f_bss, 0, sizeof(f_bss));
411 if (write(a_new, &f_bss, sizeof(f_bss)) != sizeof(f_bss))
413 PERROR("failed to write bss header");
416 size=lseek(a_new, 0, SEEK_CUR);
417 CHECK_AOUT_POS(size);
419 /* copy eveything else until start of data */
420 size = f_data_s_scnptr - lseek (a_out, 0, SEEK_CUR);
422 printf ("copying executable up to data section ... %lx bytes\n",
424 dup_file_area(a_out, a_new, size);
426 CHECK_AOUT_POS(f_data_s_scnptr);
428 if (!sections_reversed)
430 /* dump bss + padding between sections, sans small bss pad */
431 printf ("dumping .bss into executable... %lx bytes\n", bss_size);
432 if (write(a_new, bss_start, bss_size) != (int)bss_size)
434 PERROR("failed to write bss section");
437 /* pad, needs to be zero */
438 bss_padding = (new_bss_size - bss_size) - BSS_PAD_SIZE;
441 PERROR("padded .bss too small");
443 printf ("padding .bss ... %lx bytes\n", bss_padding);
444 empty_space = malloc(bss_padding);
445 memset(empty_space, 0, bss_padding);
446 if (write(a_new, empty_space, bss_padding) != (int)bss_padding)
448 PERROR("failed to write bss section");
453 /* tell dumped version not to free pure heap */
454 static_heap_dumped = 1;
455 /* Get a pointer to the raw data in our address space. */
456 printf ("dumping .data section... %lx bytes\n", data_size);
457 if (write(a_new, data_start_va, data_size) != (int)data_size)
459 PERROR("failed to write data section");
461 /* were going to use free again ... */
462 static_heap_dumped = 0;
464 size = lseek(a_out, f_data_s_scnptr + data_size, SEEK_SET);
466 if (!sections_reversed)
468 size = f_nextdata_s_scnptr - size;
469 dup_file_area(a_out, a_new, size);
473 /* need to pad to bss with data in file */
474 printf ("padding .data ... %lx bytes\n", data_padding);
475 size = (f_bss_s_vaddr - f_data_s_vaddr) - data_size;
476 dup_file_area(a_out, a_new, size);
478 /* dump bss + padding between sections */
479 printf ("dumping .bss into executable... %lx bytes\n", bss_size);
480 if (write(a_new, bss_start, bss_size) != (int)bss_size)
482 PERROR("failed to write bss section");
485 /* pad, needs to be zero */
486 bss_padding = (new_bss_size - bss_size) - BSS_PAD_SIZE;
489 PERROR("padded .bss too small");
491 printf ("padding .bss ... %lx bytes\n", bss_padding);
492 empty_space = malloc(bss_padding);
493 memset(empty_space, 0, bss_padding);
494 if (write(a_new, empty_space, bss_padding) != (int)bss_padding)
496 PERROR("failed to write bss section");
499 if (lseek(a_new, 0, SEEK_CUR) != f_nextdata.s_scnptr)
501 printf("at %lx should be at %lx\n",
502 lseek(a_new, 0, SEEK_CUR),
503 f_nextdata.s_scnptr);
504 PERROR("file positioning error\n");
506 lseek(a_out, f_nextdata_s_scnptr, SEEK_SET);
509 CHECK_AOUT_POS(f_nextdata_s_scnptr);
511 /* now dump - nextdata don't need to do this cygwin ds is in .data! */
512 printf ("dumping following data section... %lx bytes\n", f_nextdata.s_size);
514 dup_file_area(a_out,a_new,f_nextdata.s_size);
516 /* write rest of file */
517 printf ("writing rest of file\n");
518 size = lseek(a_out, 0, SEEK_END);
519 size = size - (f_nextdata_s_scnptr + f_nextdata.s_size); /* length remaining in a_out */
520 lseek(a_out, f_nextdata_s_scnptr + f_nextdata.s_size, SEEK_SET);
522 dup_file_area(a_out, a_new, size);
526 * copy from aout to anew
528 static void dup_file_area(int a_out, int a_new, long size)
532 for (; size > 0; size -= sizeof (page))
534 n = size > sizeof (page) ? sizeof (page) : size;
535 if (read (a_out, page, n) != n || write (a_new, page, n) != n)
537 PERROR ("dump_out()");
543 static void write_int_to_bss(int a_out, int a_new, void* va, void* newval)
547 cpos = lseek(a_new, 0, SEEK_CUR);
548 if (va < bss_start || va > bss_start + f_data.s_size)
550 PERROR("address not in data space\n");
552 lseek(a_new, f_data.s_scnptr + ((unsigned long)va -
553 (unsigned long)bss_start), SEEK_SET);
554 if (write(a_new, newval, sizeof(int)) != (int)sizeof(int))
556 PERROR("failed to write int value");
558 lseek(a_new, cpos, SEEK_SET);
562 #endif /* HAVE_A_OUT_H */