src/unexapollo.c

   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
  23 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26
  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_nscns*sizeof (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 }