1/* unexapollo.c -- COFF File UNEXEC for GNU Emacs on Apollo SR10.x
2   Copyright (C) 1988, 1994, 2001, 2002, 2003, 2004,
3                 2005, 2006, 2007  Free Software Foundation, Inc.
4
5This file is part of GNU Emacs.
6
7GNU Emacs is free software; you can redistribute it and/or modify
8it under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 2, or (at your option)
10any later version.
11
12GNU Emacs is distributed in the hope that it will be useful,
13but WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15GNU General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along with GNU Emacs; see the file COPYING.  If not, write to
19the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
20Boston, MA 02110-1301, USA.  */
21
22/* Written by Leonard N. Zubkoff.  */
23
24#ifdef HAVE_CONFIG_H
25#include <config.h>
26#endif
27
28#include <fcntl.h>
29
30
31#include <a.out.h>
32#include <sys/file.h>
33#include <apollo/base.h>
34#include <apollo/ios.h>
35#include <apollo/type_uids.h>
36#include <apollo/dst.h>
37
38
39#define DST_RECORD_HDR_SIZE	2
40#define LONG_ALIGN(X)		(((X)+3)&(~3))
41
42
43void
44unexec (target_file_name, source_file_name)
45     char *target_file_name, *source_file_name;
46{
47  struct filehdr file_header;
48  struct aouthdr domain_header;
49  struct scnhdr *section, *sections, *sections_limit;
50  struct scnhdr *first_data_section, *last_data_section;
51  struct scnhdr *rwdi_section, *blocks_section;
52  struct reloc reloc_entry;
53  unsigned long data_size, old_data_section_size, source_file_offset_past_rwdi;
54  unsigned char buffer[4096];
55  long delta_before_rwdi, delta_after_rwdi, byte_count;
56  long first_changed_vaddr, old_rwdi_vaddr, i;
57  ios_$id_t target_file, source_file;
58  status_$t status;
59  /* Open the Source File. */
60  if ((source_file = open (source_file_name, O_RDONLY)) < 0)
61    error ("cannot open source file for input");
62  /* Read the File Header. */
63  if (read (source_file, &file_header, sizeof (file_header)) != sizeof (file_header))
64    error ("cannot read file header");
65
66  /* Read the Domain Header. */
67  if (read (source_file, &domain_header, sizeof (domain_header))
68      != sizeof (domain_header))
69    error ("cannot read domain header");
70  /* Read the Section Headers. */
71  sections =
72    (struct scnhdr *) malloc (file_header.f_nscns*sizeof (struct scnhdr));
73  if (sections == (struct scnhdr *) 0)
74    error ("cannot allocate section header storage");
75  sections_limit = sections + file_header.f_nscns;
76  if (read (source_file, sections, file_header.f_nscns*sizeof (struct scnhdr))
77      != file_header.f_nscns*sizeof (struct scnhdr))
78    error ("cannot read section headers");
79  /* Compute the new Size of the Data Section. */
80  data_size = sbrk (0) - domain_header.data_start;
81  delta_before_rwdi = delta_after_rwdi = data_size - domain_header.dsize;
82  old_rwdi_vaddr = 0;
83  /* Find and Deallocate the .rwdi Section Information. */
84  for (rwdi_section = sections; rwdi_section != sections_limit; rwdi_section++)
85    if (strcmp (rwdi_section->s_name, ".rwdi") == 0)
86      {
87	/* If there are relocation entries, we cannot "unrelocate" them. */
88	if (rwdi_section->s_nreloc > 0)
89	  error (".rwdi section needs relocation - cannot dump Emacs");
90	delta_after_rwdi = delta_before_rwdi - rwdi_section->s_size;
91	old_rwdi_vaddr = rwdi_section->s_vaddr;
92	rwdi_section->s_paddr = 0;
93	rwdi_section->s_vaddr = 0;
94	rwdi_section->s_scnptr = 0;
95	rwdi_section->s_size = 0;
96	source_file_offset_past_rwdi = (rwdi_section+1)->s_scnptr;
97	break;
98      }
99  /* Skip over the Text Section Headers. */
100  for (section = sections; (section->s_flags & STYP_TEXT) != 0; section++) ;
101  /*
102    Find the First and Last Data Sections and Fixup
103    Section Header Relocation Pointers.
104    */
105  first_data_section = last_data_section = (struct scnhdr *) 0;
106  for (; section != sections_limit; section++)
107    {
108      if ((section->s_flags & STYP_DATA) != 0)
109	{
110	  if (first_data_section == (struct scnhdr *) 0)
111	    first_data_section = section;
112	  last_data_section = section;
113	}
114      if (section->s_relptr != 0)
115	section->s_relptr += delta_after_rwdi;
116    }
117  /* Increment the Size of the Last Data Section. */
118  old_data_section_size = last_data_section->s_size;
119  last_data_section->s_size += delta_before_rwdi;
120
121  /* Update the File Header and Domain Header. */
122  file_header.f_symptr += delta_after_rwdi;
123  domain_header.dsize = data_size;
124  domain_header.bsize = 0;
125  /* Skip over subsequent Bss Section Headers. */
126  for (section = last_data_section+1;
127       (section->s_flags & STYP_BSS) != 0; section++) ;
128  /* Update the remaining Section Headers. */
129  blocks_section = (struct scnhdr *) 0;
130  first_changed_vaddr = 0;
131  for (; section != sections_limit; section++)
132    {
133      long delta = (section < rwdi_section ? delta_before_rwdi : delta_after_rwdi);
134      if (section->s_paddr != 0)
135	section->s_paddr += delta;
136      if (section->s_vaddr != 0)
137	{
138	  if (first_changed_vaddr == 0)
139	    first_changed_vaddr = section->s_vaddr;
140	  section->s_vaddr += delta;
141	}
142      if (section->s_scnptr != 0)
143	section->s_scnptr += delta;
144      if (strcmp (section->s_name, ".blocks") == 0)
145	blocks_section = section;
146      else if (strcmp (section->s_name, ".sri") == 0 &&
147	       domain_header.o_sri != 0)
148	domain_header.o_sri += delta;
149      else if (strcmp (section->s_name, ".inlib") == 0 &&
150	       domain_header.o_inlib != 0)
151	domain_header.o_inlib += delta;
152    }
153  /* Open the Target File. */
154  ios_$create (target_file_name, strlen (target_file_name), coff_$uid,
155	       ios_$recreate_mode, ios_$write_opt, &target_file, &status);
156  if (status.all != status_$ok)
157    error ("cannot open target file for output");
158  /* Write the File Header. */
159  if (write (target_file, &file_header, sizeof (file_header)) != sizeof (file_header))
160    error ("cannot write file header");
161  /* Write the Domain Header. */
162  if (write (target_file, &domain_header, sizeof (domain_header))
163      != sizeof (domain_header))
164    error ("cannot write domain header");
165  /* Write the Section Headers. */
166  if (write (target_file, sections, file_header.f_nscns*sizeof (struct scnhdr))
167      != file_header.f_nscns*sizeof (struct scnhdr))
168    error ("cannot write section headers");
169  /* Copy the Allocated Sections. */
170  for (section = sections; section != first_data_section; section++)
171    if (section->s_scnptr != 0)
172      CopyData (target_file, source_file, LONG_ALIGN(section->s_size));
173  /* Write the Expanded Data Segment. */
174  if (write (target_file, first_data_section->s_vaddr, data_size) != data_size)
175    error ("cannot write new data section");
176
177  /* Skip over the Last Data Section and Copy until the .rwdi Section. */
178  if (lseek (source_file, last_data_section->s_scnptr
179	     +old_data_section_size, L_SET) == -1)
180    error ("cannot seek past data section");
181  for (section = last_data_section+1; section != rwdi_section; section++)
182    if (section->s_scnptr != 0)
183      CopyData (target_file, source_file, LONG_ALIGN(section->s_size));
184  /* Skip over the .rwdi Section and Copy Remainder of Source File. */
185  if (lseek (source_file, source_file_offset_past_rwdi, L_SET) == -1)
186    error ("cannot seek past .rwdi section");
187  while ((byte_count = read (source_file, buffer, sizeof (buffer))) > 0)
188    if (write (target_file, buffer, byte_count) != byte_count)
189      error ("cannot write data");
190  /* Unrelocate .data references to Global Symbols. */
191  for (section = first_data_section; section <= last_data_section; section++)
192    for (i = 0; i < section->s_nreloc; i++)
193      {
194	if  (lseek (source_file, section->s_relptr
195		    +i*sizeof (struct reloc)-delta_after_rwdi, L_SET) == -1)
196	  error ("cannot seek to relocation info");
197	if (read (source_file, &reloc_entry, sizeof (reloc_entry))
198	    != sizeof (reloc_entry))
199	  error ("cannot read reloc entry");
200	if (lseek (source_file, reloc_entry.r_vaddr-section->s_vaddr
201		   +section->s_scnptr, L_SET) == -1)
202	  error ("cannot seek to data element");
203	if (lseek (target_file, reloc_entry.r_vaddr-section->s_vaddr
204		   +section->s_scnptr, L_SET) == -1)
205	  error ("cannot seek to data element");
206	if (read (source_file, buffer, 4) != 4)
207	  error ("cannot read data element");
208	if (write (target_file, buffer, 4) != 4)
209	  error ("cannot write data element");
210      }
211
212  /* Correct virtual addresses in .blocks section. */
213  if (blocks_section != (struct scnhdr *) 0)
214    {
215      dst_rec_t dst_record;
216      dst_rec_comp_unit_t *comp_unit;
217      unsigned short number_of_sections;
218      unsigned long section_base;
219      unsigned long section_offset = 0;
220      /* Find section tables and update section base addresses. */
221      while (section_offset < blocks_section->s_size)
222	{
223	  if (lseek (target_file,
224		     blocks_section->s_scnptr+section_offset, L_SET) == -1)
225	    error ("cannot seek to comp unit record");
226	  /* Handle pad records before the comp unit record. */
227	  if (read (target_file, &dst_record, DST_RECORD_HDR_SIZE)
228	      != DST_RECORD_HDR_SIZE)
229	    error ("cannot read dst record tag");
230	  if (dst_record.rec_type == dst_typ_pad)
231	    section_offset += DST_RECORD_HDR_SIZE;
232	  else if (dst_record.rec_type == dst_typ_comp_unit)
233	    {
234	      comp_unit = &dst_record.rec_data.comp_unit_;
235	      if  (read (target_file, comp_unit, sizeof (*comp_unit))
236		   != sizeof (*comp_unit))
237		error ("cannot read comp unit record");
238	      if (lseek (target_file, blocks_section->s_scnptr
239			 +section_offset
240#if dst_version_major == 1 && dst_version_minor < 4
241			 +comp_unit->section_table
242#else
243			 +comp_unit->section_table.rel_offset
244#endif
245			 +DST_RECORD_HDR_SIZE,
246			 L_SET) == -1)
247		error ("cannot seek to section table");
248	      if (read (target_file, &number_of_sections, sizeof (number_of_sections))
249		  != sizeof (number_of_sections))
250		error ("cannot read section table size");
251	      for (i = 0; i < number_of_sections; i++)
252		{
253		  if (read (target_file, &section_base, sizeof (section_base))
254		      != sizeof (section_base))
255		    error ("cannot read section base value");
256		  if (section_base < first_changed_vaddr)
257		    continue;
258		  else if (section_base < old_rwdi_vaddr)
259		    section_base += delta_before_rwdi;
260		  else section_base += delta_after_rwdi;
261		  if (lseek (target_file, -sizeof (section_base), L_INCR) == -1)
262		    error ("cannot seek to section base value");
263		  if (write (target_file, &section_base, sizeof (section_base))
264		      != sizeof (section_base))
265		    error ("cannot write section base");
266		}
267	      section_offset += comp_unit->data_size;
268	    }
269	  else error ("unexpected dst record type");
270	}
271    }
272
273  if (close (source_file) == -1)
274    error("cannot close source file");
275  if (close (target_file) == -1)
276    error ("cannot close target file");
277}
278
279
280static
281CopyData (target_file, source_file, total_byte_count)
282     int target_file, source_file;
283     long total_byte_count;
284{
285  unsigned char buffer[4096];
286  long byte_count;
287  while (total_byte_count > 0)
288    {
289      if (total_byte_count > sizeof (buffer))
290	byte_count = sizeof (buffer);
291      else byte_count = total_byte_count;
292      if (read (source_file, buffer, byte_count) != byte_count)
293	error ("cannot read data");
294      if (write (target_file, buffer, byte_count) != byte_count)
295	error ("cannot write data");
296      total_byte_count -= byte_count;
297    }
298}
299
300/* arch-tag: 783ebbdf-7d26-4df8-9469-17a1747dce96
301   (do not change this comment) */
302