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