[bpt/emacs.git] / src / unexapollo.c

/* unexapollo.c -- COFF File UNEXEC for GNU Emacs on Apollo SR10.x
   Copyright (C) 1988, 1994 Free Software Foundation, Inc.

This file is part of GNU Emacs.

GNU Emacs is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Emacs; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* Written by Leonard N. Zubkoff.  */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <fcntl.h>


#include <a.out.h>
#include <sys/file.h>
#include <apollo/base.h>
#include <apollo/ios.h>
#include <apollo/type_uids.h>
#include <apollo/dst.h>


#define DST_RECORD_HDR_SIZE	2
#define LONG_ALIGN(X)		(((X)+3)&(~3))


void
unexec (target_file_name, source_file_name)
     char *target_file_name, *source_file_name;
{
  struct filehdr file_header;
  struct aouthdr domain_header;
  struct scnhdr *section, *sections, *sections_limit;
  struct scnhdr *first_data_section, *last_data_section;
  struct scnhdr *rwdi_section, *blocks_section;
  struct reloc reloc_entry;
  unsigned long data_size, old_data_section_size, source_file_offset_past_rwdi;
  unsigned char buffer[4096];
  long delta_before_rwdi, delta_after_rwdi, byte_count;
  long first_changed_vaddr, old_rwdi_vaddr, i;
  ios_$id_t target_file, source_file;
  status_$t status;
  /* Open the Source File. */
  if ((source_file = open (source_file_name, O_RDONLY)) < 0)
    error ("cannot open source file for input");
  /* Read the File Header. */
  if (read (source_file, &file_header, sizeof (file_header)) != sizeof (file_header))
    error ("cannot read file header");
  \f
  /* Read the Domain Header. */
  if (read (source_file, &domain_header, sizeof (domain_header))
      != sizeof (domain_header))
    error ("cannot read domain header");
  /* Read the Section Headers. */
  sections =
    (struct scnhdr *) malloc (file_header.f_nscns*sizeof (struct scnhdr));
  if (sections == (struct scnhdr *) 0)
    error ("cannot allocate section header storage");
  sections_limit = sections + file_header.f_nscns;
  if (read (source_file, sections, file_header.f_nscns*sizeof (struct scnhdr))
      != file_header.f_nscns*sizeof (struct scnhdr))
    error ("cannot read section headers");
  /* Compute the new Size of the Data Section. */
  data_size = sbrk (0) - domain_header.data_start;
  delta_before_rwdi = delta_after_rwdi = data_size - domain_header.dsize;
  old_rwdi_vaddr = 0;
  /* Find and Deallocate the .rwdi Section Information. */
  for (rwdi_section = sections; rwdi_section != sections_limit; rwdi_section++)
    if (strcmp (rwdi_section->s_name, ".rwdi") == 0)
      {
	/* If there are relocation entries, we cannot "unrelocate" them. */
	if (rwdi_section->s_nreloc > 0)
	  error (".rwdi section needs relocation - cannot dump Emacs");
	delta_after_rwdi = delta_before_rwdi - rwdi_section->s_size;
	old_rwdi_vaddr = rwdi_section->s_vaddr;
	rwdi_section->s_paddr = 0;
	rwdi_section->s_vaddr = 0;
	rwdi_section->s_scnptr = 0;
	rwdi_section->s_size = 0;
	source_file_offset_past_rwdi = (rwdi_section+1)->s_scnptr;
	break;
      }
  /* Skip over the Text Section Headers. */
  for (section = sections; (section->s_flags & STYP_TEXT) != 0; section++) ;
  /*
    Find the First and Last Data Sections and Fixup
    Section Header Relocation Pointers.
    */
  first_data_section = last_data_section = (struct scnhdr *) 0;
  for (; section != sections_limit; section++)
    {
      if ((section->s_flags & STYP_DATA) != 0)
	{
	  if (first_data_section == (struct scnhdr *) 0)
	    first_data_section = section;
	  last_data_section = section;
	}
      if (section->s_relptr != 0)
	section->s_relptr += delta_after_rwdi;
    }
  /* Increment the Size of the Last Data Section. */
  old_data_section_size = last_data_section->s_size;
  last_data_section->s_size += delta_before_rwdi;
  \f
  /* Update the File Header and Domain Header. */
  file_header.f_symptr += delta_after_rwdi;
  domain_header.dsize = data_size;
  domain_header.bsize = 0;
  /* Skip over subsequent Bss Section Headers. */
  for (section = last_data_section+1;
       (section->s_flags & STYP_BSS) != 0; section++) ;
  /* Update the remaining Section Headers. */
  blocks_section = (struct scnhdr *) 0;
  first_changed_vaddr = 0;
  for (; section != sections_limit; section++)
    {
      long delta = (section < rwdi_section ? delta_before_rwdi : delta_after_rwdi);
      if (section->s_paddr != 0)
	section->s_paddr += delta;
      if (section->s_vaddr != 0)
	{
	  if (first_changed_vaddr == 0)
	    first_changed_vaddr = section->s_vaddr;
	  section->s_vaddr += delta;
	}
      if (section->s_scnptr != 0)
	section->s_scnptr += delta;
      if (strcmp (section->s_name, ".blocks") == 0)
	blocks_section = section;
      else if (strcmp (section->s_name, ".sri") == 0 &&
	       domain_header.o_sri != 0)
	domain_header.o_sri += delta;
      else if (strcmp (section->s_name, ".inlib") == 0 &&
	       domain_header.o_inlib != 0)
	domain_header.o_inlib += delta;
    }
  /* Open the Target File. */
  ios_$create (target_file_name, strlen (target_file_name), coff_$uid,
	       ios_$recreate_mode, ios_$write_opt, &target_file, &status);
  if (status.all != status_$ok)
    error ("cannot open target file for output");
  /* Write the File Header. */
  if (write (target_file, &file_header, sizeof (file_header)) != sizeof (file_header))
    error ("cannot write file header");
  /* Write the Domain Header. */
  if (write (target_file, &domain_header, sizeof (domain_header))
      != sizeof (domain_header))
    error ("cannot write domain header");
  /* Write the Section Headers. */
  if (write (target_file, sections, file_header.f_nscns*sizeof (struct scnhdr))
      != file_header.f_nscns*sizeof (struct scnhdr))
    error ("cannot write section headers");
  /* Copy the Allocated Sections. */
  for (section = sections; section != first_data_section; section++)
    if (section->s_scnptr != 0)
      CopyData (target_file, source_file, LONG_ALIGN(section->s_size));
  /* Write the Expanded Data Segment. */
  if (write (target_file, first_data_section->s_vaddr, data_size) != data_size)
    error ("cannot write new data section");
  \f
  /* Skip over the Last Data Section and Copy until the .rwdi Section. */
  if (lseek (source_file, last_data_section->s_scnptr
	     +old_data_section_size, L_SET) == -1)
    error ("cannot seek past data section");
  for (section = last_data_section+1; section != rwdi_section; section++)
    if (section->s_scnptr != 0)
      CopyData (target_file, source_file, LONG_ALIGN(section->s_size));
  /* Skip over the .rwdi Section and Copy Remainder of Source File. */
  if (lseek (source_file, source_file_offset_past_rwdi, L_SET) == -1)
    error ("cannot seek past .rwdi section");
  while ((byte_count = read (source_file, buffer, sizeof (buffer))) > 0)
    if (write (target_file, buffer, byte_count) != byte_count)
      error ("cannot write data");
  /* Unrelocate .data references to Global Symbols. */
  for (section = first_data_section; section <= last_data_section; section++)
    for (i = 0; i < section->s_nreloc; i++)
      {
	if  (lseek (source_file, section->s_relptr
		    +i*sizeof (struct reloc)-delta_after_rwdi, L_SET) == -1)
	  error ("cannot seek to relocation info");
	if (read (source_file, &reloc_entry, sizeof (reloc_entry))
	    != sizeof (reloc_entry))
	  error ("cannot read reloc entry");
	if (lseek (source_file, reloc_entry.r_vaddr-section->s_vaddr
		   +section->s_scnptr, L_SET) == -1)
	  error ("cannot seek to data element");
	if (lseek (target_file, reloc_entry.r_vaddr-section->s_vaddr
		   +section->s_scnptr, L_SET) == -1)
	  error ("cannot seek to data element");
	if (read (source_file, buffer, 4) != 4)
	  error ("cannot read data element");
	if (write (target_file, buffer, 4) != 4)
	  error ("cannot write data element");
      }
  \f
  /* Correct virtual addresses in .blocks section. */
  if (blocks_section != (struct scnhdr *) 0)
    {
      dst_rec_t dst_record;
      dst_rec_comp_unit_t *comp_unit;
      unsigned short number_of_sections;
      unsigned long section_base;
      unsigned long section_offset = 0;
      /* Find section tables and update section base addresses. */
      while (section_offset < blocks_section->s_size)
	{
	  if (lseek (target_file,
		     blocks_section->s_scnptr+section_offset, L_SET) == -1)
	    error ("cannot seek to comp unit record");
	  /* Handle pad records before the comp unit record. */
	  if (read (target_file, &dst_record, DST_RECORD_HDR_SIZE)
	      != DST_RECORD_HDR_SIZE)
	    error ("cannot read dst record tag");
	  if (dst_record.rec_type == dst_typ_pad)
	    section_offset += DST_RECORD_HDR_SIZE;
	  else if (dst_record.rec_type == dst_typ_comp_unit)
	    {
	      comp_unit = &dst_record.rec_data.comp_unit_;
	      if  (read (target_file, comp_unit, sizeof (*comp_unit))
		   != sizeof (*comp_unit))
		error ("cannot read comp unit record");
	      if (lseek (target_file, blocks_section->s_scnptr
			 +section_offset
#if dst_version_major == 1 && dst_version_minor < 4
			 +comp_unit->section_table
#else
			 +comp_unit->section_table.rel_offset
#endif
			 +DST_RECORD_HDR_SIZE,
			 L_SET) == -1)
		error ("cannot seek to section table");
	      if (read (target_file, &number_of_sections, sizeof (number_of_sections))
		  != sizeof (number_of_sections))
		error ("cannot read section table size");
	      for (i = 0; i < number_of_sections; i++)
		{
		  if (read (target_file, &section_base, sizeof (section_base))
		      != sizeof (section_base))
		    error ("cannot read section base value");
		  if (section_base < first_changed_vaddr)
		    continue;
		  else if (section_base < old_rwdi_vaddr)
		    section_base += delta_before_rwdi;
		  else section_base += delta_after_rwdi;
		  if (lseek (target_file, -sizeof (section_base), L_INCR) == -1)
		    error ("cannot seek to section base value");
		  if (write (target_file, &section_base, sizeof (section_base))
		      != sizeof (section_base))
		    error ("cannot write section base");
		}
	      section_offset += comp_unit->data_size;
	    }
	  else error ("unexpected dst record type");
	}
    }
  \f
  if (close (source_file) == -1)
    error("cannot close source file");
  if (close (target_file) == -1)
    error ("cannot close target file");
}


static
CopyData (target_file, source_file, total_byte_count)
     int target_file, source_file;
     long total_byte_count;
{
  unsigned char buffer[4096];
  long byte_count;
  while (total_byte_count > 0)
    {
      if (total_byte_count > sizeof (buffer))
	byte_count = sizeof (buffer);
      else byte_count = total_byte_count;
      if (read (source_file, buffer, byte_count) != byte_count)
	error ("cannot read data");
      if (write (target_file, buffer, byte_count) != byte_count)
	error ("cannot write data");
      total_byte_count -= byte_count;
    }
}

/* arch-tag: 783ebbdf-7d26-4df8-9469-17a1747dce96
   (do not change this comment) */
Commit	Line	Data
5303ab61 RS	1	/* unexapollo.c -- COFF File UNEXEC for GNU Emacs on Apollo SR10.x
	2	Copyright (C) 1988, 1994 Free Software Foundation, Inc.
	3
	4	This file is part of GNU Emacs.
	5
	6	GNU Emacs is free software; you can redistribute it and/or modify
	7	it under the terms of the GNU General Public License as published by
	8	the Free Software Foundation; either version 2, or (at your option)
	9	any later version.
	10
	11	GNU Emacs is distributed in the hope that it will be useful,
	12	but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	GNU General Public License for more details.
	15
	16	You should have received a copy of the GNU General Public License
	17	along with GNU Emacs; 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. */
	20
	21	/* Written by Leonard N. Zubkoff. */
	22
4838e624 PJ	23	#ifdef HAVE_CONFIG_H
	24	#include <config.h>
	25	#endif
	26
5303ab61 RS	27	#include <fcntl.h>
	28
	29
	30	#include <a.out.h>
	31	#include <sys/file.h>
	32	#include <apollo/base.h>
	33	#include <apollo/ios.h>
	34	#include <apollo/type_uids.h>
	35	#include <apollo/dst.h>
	36
	37
	38	#define DST_RECORD_HDR_SIZE 2
	39	#define LONG_ALIGN(X) (((X)+3)&(~3))
	40
	41
	42	void
	43	unexec (target_file_name, source_file_name)
	44	char target_file_name, source_file_name;
	45	{
	46	struct filehdr file_header;
	47	struct aouthdr domain_header;
	48	struct scnhdr section, sections, *sections_limit;
	49	struct scnhdr first_data_section, last_data_section;
	50	struct scnhdr rwdi_section, blocks_section;
	51	struct reloc reloc_entry;
	52	unsigned long data_size, old_data_section_size, source_file_offset_past_rwdi;
	53	unsigned char buffer[4096];
	54	long delta_before_rwdi, delta_after_rwdi, byte_count;
	55	long first_changed_vaddr, old_rwdi_vaddr, i;
	56	ios_$id_t target_file, source_file;
	57	status_$t status;
	58	/* Open the Source File. */
	59	if ((source_file = open (source_file_name, O_RDONLY)) < 0)
	60	error ("cannot open source file for input");
	61	/* Read the File Header. */
	62	if (read (source_file, &file_header, sizeof (file_header)) != sizeof (file_header))
	63	error ("cannot read file header");
	64	\f
	65	/* Read the Domain Header. */
	66	if (read (source_file, &domain_header, sizeof (domain_header))
	67	!= sizeof (domain_header))
	68	error ("cannot read domain header");
	69	/* Read the Section Headers. */
	70	sections =
	71	(struct scnhdr ) malloc (file_header.f_nscnssizeof (struct scnhdr));
	72	if (sections == (struct scnhdr *) 0)
	73	error ("cannot allocate section header storage");
	74	sections_limit = sections + file_header.f_nscns;
	75	if (read (source_file, sections, file_header.f_nscns*sizeof (struct scnhdr))
	76	!= file_header.f_nscns*sizeof (struct scnhdr))
	77	error ("cannot read section headers");
	78	/* Compute the new Size of the Data Section. */
	79	data_size = sbrk (0) - domain_header.data_start;
	80	delta_before_rwdi = delta_after_rwdi = data_size - domain_header.dsize;
	81	old_rwdi_vaddr = 0;
	82	/* Find and Deallocate the .rwdi Section Information. */
	83	for (rwdi_section = sections; rwdi_section != sections_limit; rwdi_section++)
	84	if (strcmp (rwdi_section->s_name, ".rwdi") == 0)
	85	{
	86	/* If there are relocation entries, we cannot "unrelocate" them. */
	87	if (rwdi_section->s_nreloc > 0)
	88	error (".rwdi section needs relocation - cannot dump Emacs");
	89	delta_after_rwdi = delta_before_rwdi - rwdi_section->s_size;
	90	old_rwdi_vaddr = rwdi_section->s_vaddr;
91	rwdi_section->s_paddr = 0;
92	rwdi_section->s_vaddr = 0;
93	rwdi_section->s_scnptr = 0;
94	rwdi_section->s_size = 0;
95	source_file_offset_past_rwdi = (rwdi_section+1)->s_scnptr;
96	break;
97	}
98	/* Skip over the Text Section Headers. */
99	for (section = sections; (section->s_flags & STYP_TEXT) != 0; section++) ;
100	/*
101	Find the First and Last Data Sections and Fixup
102	Section Header Relocation Pointers.
103	*/
104	first_data_section = last_data_section = (struct scnhdr *) 0;
105	for (; section != sections_limit; section++)
106	{
107	if ((section->s_flags & STYP_DATA) != 0)
108	{
109	if (first_data_section == (struct scnhdr *) 0)
110	first_data_section = section;
111	last_data_section = section;
112	}
113	if (section->s_relptr != 0)
114	section->s_relptr += delta_after_rwdi;
115	}
116	/* Increment the Size of the Last Data Section. */
117	old_data_section_size = last_data_section->s_size;
118	last_data_section->s_size += delta_before_rwdi;
119	\f
120	/* Update the File Header and Domain Header. */
121	file_header.f_symptr += delta_after_rwdi;
122	domain_header.dsize = data_size;
123	domain_header.bsize = 0;
124	/* Skip over subsequent Bss Section Headers. */
125	for (section = last_data_section+1;
126	(section->s_flags & STYP_BSS) != 0; section++) ;
127	/* Update the remaining Section Headers. */
128	blocks_section = (struct scnhdr *) 0;
129	first_changed_vaddr = 0;
130	for (; section != sections_limit; section++)
131	{
132	long delta = (section < rwdi_section ? delta_before_rwdi : delta_after_rwdi);
133	if (section->s_paddr != 0)
134	section->s_paddr += delta;
135	if (section->s_vaddr != 0)
136	{
137	if (first_changed_vaddr == 0)
138	first_changed_vaddr = section->s_vaddr;
139	section->s_vaddr += delta;
140	}
141	if (section->s_scnptr != 0)
142	section->s_scnptr += delta;
143	if (strcmp (section->s_name, ".blocks") == 0)
144	blocks_section = section;
145	else if (strcmp (section->s_name, ".sri") == 0 &&
146	domain_header.o_sri != 0)
147	domain_header.o_sri += delta;
148	else if (strcmp (section->s_name, ".inlib") == 0 &&
149	domain_header.o_inlib != 0)
150	domain_header.o_inlib += delta;
151	}
152	/* Open the Target File. */
153	ios_$create (target_file_name, strlen (target_file_name), coff_$uid,
154	ios_$recreate_mode, ios_$write_opt, &target_file, &status);
155	if (status.all != status_$ok)
156	error ("cannot open target file for output");
157	/* Write the File Header. */
158	if (write (target_file, &file_header, sizeof (file_header)) != sizeof (file_header))
159	error ("cannot write file header");
160	/* Write the Domain Header. */
161	if (write (target_file, &domain_header, sizeof (domain_header))
162	!= sizeof (domain_header))
163	error ("cannot write domain header");
164	/* Write the Section Headers. */
165	if (write (target_file, sections, file_header.f_nscns*sizeof (struct scnhdr))
166	!= file_header.f_nscns*sizeof (struct scnhdr))
167	error ("cannot write section headers");
168	/* Copy the Allocated Sections. */
169	for (section = sections; section != first_data_section; section++)
170	if (section->s_scnptr != 0)
171	CopyData (target_file, source_file, LONG_ALIGN(section->s_size));
172	/* Write the Expanded Data Segment. */
173	if (write (target_file, first_data_section->s_vaddr, data_size) != data_size)
174	error ("cannot write new data section");
175	\f
176	/* Skip over the Last Data Section and Copy until the .rwdi Section. */
177	if (lseek (source_file, last_data_section->s_scnptr
178	+old_data_section_size, L_SET) == -1)
179	error ("cannot seek past data section");
180	for (section = last_data_section+1; section != rwdi_section; section++)
181	if (section->s_scnptr != 0)
182	CopyData (target_file, source_file, LONG_ALIGN(section->s_size));
183	/* Skip over the .rwdi Section and Copy Remainder of Source File. */
184	if (lseek (source_file, source_file_offset_past_rwdi, L_SET) == -1)
185	error ("cannot seek past .rwdi section");
186	while ((byte_count = read (source_file, buffer, sizeof (buffer))) > 0)
187	if (write (target_file, buffer, byte_count) != byte_count)
188	error ("cannot write data");
189	/* Unrelocate .data references to Global Symbols. */
190	for (section = first_data_section; section <= last_data_section; section++)
191	for (i = 0; i < section->s_nreloc; i++)
192	{
193	if (lseek (source_file, section->s_relptr
194	+i*sizeof (struct reloc)-delta_after_rwdi, L_SET) == -1)
195	error ("cannot seek to relocation info");
196	if (read (source_file, &reloc_entry, sizeof (reloc_entry))
197	!= sizeof (reloc_entry))
198	error ("cannot read reloc entry");
199	if (lseek (source_file, reloc_entry.r_vaddr-section->s_vaddr
200	+section->s_scnptr, L_SET) == -1)
201	error ("cannot seek to data element");
202	if (lseek (target_file, reloc_entry.r_vaddr-section->s_vaddr
203	+section->s_scnptr, L_SET) == -1)
204	error ("cannot seek to data element");
205	if (read (source_file, buffer, 4) != 4)
206	error ("cannot read data element");
207	if (write (target_file, buffer, 4) != 4)
208	error ("cannot write data element");
209	}
210	\f
211	/* Correct virtual addresses in .blocks section. */
212	if (blocks_section != (struct scnhdr *) 0)
213	{
214	dst_rec_t dst_record;
215	dst_rec_comp_unit_t *comp_unit;
216	unsigned short number_of_sections;
217	unsigned long section_base;
218	unsigned long section_offset = 0;
219	/* Find section tables and update section base addresses. */
220	while (section_offset < blocks_section->s_size)
221	{
222	if (lseek (target_file,
223	blocks_section->s_scnptr+section_offset, L_SET) == -1)
224	error ("cannot seek to comp unit record");
225	/* Handle pad records before the comp unit record. */
226	if (read (target_file, &dst_record, DST_RECORD_HDR_SIZE)
227	!= DST_RECORD_HDR_SIZE)
228	error ("cannot read dst record tag");
229	if (dst_record.rec_type == dst_typ_pad)
230	section_offset += DST_RECORD_HDR_SIZE;
231	else if (dst_record.rec_type == dst_typ_comp_unit)
232	{
233	comp_unit = &dst_record.rec_data.comp_unit_;
234	if (read (target_file, comp_unit, sizeof (*comp_unit))
235	!= sizeof (*comp_unit))
236	error ("cannot read comp unit record");
237	if (lseek (target_file, blocks_section->s_scnptr
238	+section_offset
239	#if dst_version_major == 1 && dst_version_minor < 4
240	+comp_unit->section_table
241	#else
242	+comp_unit->section_table.rel_offset
243	#endif
244	+DST_RECORD_HDR_SIZE,
245	L_SET) == -1)
246	error ("cannot seek to section table");
247	if (read (target_file, &number_of_sections, sizeof (number_of_sections))
248	!= sizeof (number_of_sections))
249	error ("cannot read section table size");
250	for (i = 0; i < number_of_sections; i++)
251	{
252	if (read (target_file, &section_base, sizeof (section_base))
253	!= sizeof (section_base))
254	error ("cannot read section base value");
255	if (section_base < first_changed_vaddr)
256	continue;
257	else if (section_base < old_rwdi_vaddr)
258	section_base += delta_before_rwdi;
259	else section_base += delta_after_rwdi;
260	if (lseek (target_file, -sizeof (section_base), L_INCR) == -1)
261	error ("cannot seek to section base value");
262	if (write (target_file, &section_base, sizeof (section_base))
263	!= sizeof (section_base))
264	error ("cannot write section base");
265	}
266	section_offset += comp_unit->data_size;
267	}
268	else error ("unexpected dst record type");
269	}
270	}
271	\f
272	if (close (source_file) == -1)
273	error("cannot close source file");
274	if (close (target_file) == -1)
275	error ("cannot close target file");
276	}
277
278
279	static
280	CopyData (target_file, source_file, total_byte_count)
281	int target_file, source_file;
282	long total_byte_count;
283	{
284	unsigned char buffer[4096];
285	long byte_count;
286	while (total_byte_count > 0)
287	{
288	if (total_byte_count > sizeof (buffer))
289	byte_count = sizeof (buffer);
290	else byte_count = total_byte_count;
291	if (read (source_file, buffer, byte_count) != byte_count)
292	error ("cannot read data");
293	if (write (target_file, buffer, byte_count) != byte_count)
294	error ("cannot write data");
295	total_byte_count -= byte_count;
296	}
297	}
ab5796a9 MB	298
	299	/* arch-tag: 783ebbdf-7d26-4df8-9469-17a1747dce96
	300	(do not change this comment) */