arch/i386-darwin/bootstrap/octave/parseelf.m

   1 function object=parseelf(path)
   2 fid = fopen(path,'r');
   3 %elf header
   4 object.elf_header=readheader(fid);
   5 %program header
   6 if object.elf_header.e_phoff > 0
   7         fseek(fid,object.elf_header.e_phoff);
   8         object.program_headers = readprogramheaders(fid,object.elf_header.e_phentsize,object.elf_header.e_phnum);
   9 end
  10 %section headers
  11 if object.elf_header.e_shoff > 0
  12         fseek(fid,object.elf_header.e_shoff);
  13         object.section_headers = readsectionheaders(fid,object.elf_header.e_shentsize,object.elf_header.e_shnum);
  14         object.strtabindex=find([object.section_headers.sh_type]==3);
  15         object.symtabindex=find([object.section_headers.sh_type]==2);
  16         %get strtabs
  17         if numel(object.strtabindex)>0
  18                 object.strtabs={object.section_headers(object.strtabindex).strings};
  19                 object.stroffsets={object.section_headers(object.strtabindex).stroffsets};
  20         end
  21         %fill in section names
  22         if object.elf_header.e_shstrndx>0
  23           fprintf('getting section names...\n')
  24                 snamesindex = find(object.strtabindex==(object.elf_header.e_shstrndx+1));
  25                 object.section_names = object.strtabs{snamesindex};
  26                 snameoffsets = object.stroffsets{snamesindex};
  27                 for i=1:numel(object.section_headers)
  28                         object.section_headers(i).name = getname(object,snamesindex,object.section_headers(i).sh_name);
  29                 end
  30                 object.section_headers(1).name = 'UNDEF';
  31         end
  32         %get symbols and fill in names
  33         if numel(object.symtabindex)>0
  34                 object.symtabs={object.section_headers(object.symtabindex).symbols};
  35                 %find .strtab
  36                 strtabindex=find(cellfun(@(c)(numel(c)==1&&c==1),strfind({object.section_headers.name},'.strtab')));
  37                 if numel(strtabindex)==1
  38                   strtabindex = find(object.strtabindex==strtabindex);
  39                   fprintf('getting symbol names...\n')
  40                   for i=1:numel(object.symtabs)
  41                     for j=1:numel(object.symtabs{i})
  42                       object.symtabs{i}(j).name = getname(object,strtabindex,object.symtabs{i}(j).st_name);
  43                       shindex = object.symtabs{i}(j).st_shndx;
  44                       if (shindex > 0)
  45                         object.symtabs{i}(j).abs_offset = object.symtabs{i}(j).st_value + object.section_headers(shindex+1).sh_offset;
  46                         object.symtabs{i}(j).section_name = object.section_headers(shindex+1).name;
  47                       else
  48                         object.symtabs{i}(j).abs_offset = -1;
  49                 end
  50               end
  51             end
  52           end
  53         end
  54 end
  55 fclose(fid);
  56
  57 function name=getname(object,tabindex,sh_name)
  58 if sh_name <=0
  59         name = '';
  60         return;
  61 end
  62 snameoffsets = object.stroffsets{tabindex};
  63 nameindex=max(find(sh_name>=snameoffsets));
  64 nameoffset=sh_name-snameoffsets(nameindex)+1;
  65 str = object.strtabs{tabindex}{nameindex};
  66 name = str(nameoffset:end);
  67
  68 function sheaders = readsectionheaders(fid,s,n)
  69 fprintf('reading sections... ');fflush(stdout);
  70 for i=1:n
  71 fprintf(' %i ',i);fflush(stdout);
  72 pos = ftell(fid);
  73 sheaders(i).sh_name=fread(fid,1,'int32');
  74 sheaders(i).sh_type=fread(fid,1,'int32');
  75 sheaders(i).sh_flags=fread(fid,1,'int32');
  76 sheaders(i).sh_addr=fread(fid,1,'int32');
  77 sheaders(i).sh_offset=fread(fid,1,'int32');
  78 sheaders(i).sh_size=fread(fid,1,'int32');
  79 sheaders(i).sh_link=fread(fid,1,'int32');
  80 sheaders(i).sh_info=fread(fid,1,'int32');
  81 sheaders(i).sh_addralign=fread(fid,1,'int32');
  82 sheaders(i).sh_entsize=fread(fid,1,'int32');
  83 switch(sheaders(i).sh_type)
  84         case 0
  85                 sheaders(i).typestr = 'null';
  86         case 1
  87                 sheaders(i).typestr = 'progbits';
  88         case 2
  89                 sheaders(i).typestr = 'symtab';
  90         case 3
  91                 sheaders(i).typestr = 'strtab';
  92         case 4
  93                 sheaders(i).typestr = 'rela';
  94         case 5
  95                 sheaders(i).typestr = 'hash';
  96         case 6
  97                 sheaders(i).typestr = 'danymic';
  98         case 7
  99                 sheaders(i).typestr = 'note';
 100         case 8
 101                 sheaders(i).typestr = 'nobits';
 102         case 9
 103                 sheaders(i).typestr = 'rel';
 104         case 10
 105                 sheaders(i).typestr = 'shlib';
 106         case 11
 107                 sheaders(i).typestr = 'dynsym';
 108         otherwise
 109                 sheaders(i).typestr = 'unknown';
 110 end
 111 if sheaders(i).sh_type == 3
 112   fprintf('str ');fflush(stdout);
 113         fseek(fid,sheaders(i).sh_offset+1);
 114         [sheaders(i).strings,sheaders(i).stroffsets] = readstrings(fid,sheaders(i).sh_offset+sheaders(i).sh_size);
 115 fseek(fid,pos+s);
 116 elseif sheaders(i).sh_type == 2
 117   fprintf('sym ');fflush(stdout);
 118         fseek(fid,sheaders(i).sh_offset);
 119         sheaders(i).symbols = readsymbols(fid,sheaders(i).sh_offset+sheaders(i).sh_size);
 120 end
 121 fseek(fid,pos+s);
 122 end
 123 fprintf('done\n');fflush(stdout);
 124
 125 function symbols = readsymbols(fid,end_offset)
 126         symbols = [];
 127         do
 128                 symbol.st_name = fread(fid,1,'int32');
 129                 symbol.st_value = fread(fid,1,'int32');
 130                 symbol.st_size = fread(fid,1,'int32');
 131                 symbol.st_info = fread(fid,1,'uchar');
 132                 symbol.st_other = fread(fid,1,'uchar');
 133                 symbol.st_shndx = fread(fid,1,'int16');
 134                 if isempty(symbols)
 135                         symbols = symbol;
 136                 else
 137                         symbols(end+1) = symbol;
 138                 end
 139         until ftell(fid)>=end_offset
 140
 141 function [strings,offsets] = readstrings(fid,end_offset)
 142         strings = {};
 143         offsets = [];
 144         offset=1;
 145         do
 146                 str = '';
 147                 offsets(end+1) = offset;
 148                 %TODO: use fscanf('%s',1);
 149                 while   (c = char(fread(fid,1,'uchar'))) != 0
 150                         str(end+1) = c;
 151                         offset = offset + 1;
 152                 end
 153                 offset = offset + 1;
 154                 strings{end+1} = str;
 155         until ftell(fid)>=end_offset
 156
 157 function pheaders = readprogramheaders(fid,s,n)
 158 fprintf('reading program headers... ');fflush(stdout);
 159 for i=1:n
 160 fprintf('%i, ',i);fflush(stdout);
 161 pos = ftell(fid);
 162 pheaders(i).p_type=fread(fid,1,'int32');
 163 pheaders(i).p_offsset=fread(fid,1,'int32');
 164 pheaders(i).p_vaddr=fread(fid,1,'int32');
 165 pheaders(i).p_paddr=fread(fid,1,'int32');
 166 pheaders(i).p_filesz=fread(fid,1,'int32');
 167 pheaders(i).p_memsz=fread(fid,1,'int32');
 168 pheaders(i).p_flags=fread(fid,1,'int32');
 169 pheaders(i).p_align=fread(fid,1,'int32');
 170 fseek(fid,pos+s)
 171 end
 172 fprintf('done\n');fflush(stdout);
 173
 174 function header=readheader(fid)
 175 fprintf('reading elf-header...\n');fflush(stdout);
 176 header.e_ident=fread(fid,16,'uchar');
 177 header.e_type=fread(fid,1,'int16');
 178 header.e_machine=fread(fid,1,'int16');
 179 header.e_version=fread(fid,1,'int32');
 180 header.e_entry=fread(fid,1,'int32');
 181 header.e_phoff=fread(fid,1,'int32');
 182 header.e_shoff=fread(fid,1,'int32');
 183 header.e_flags=fread(fid,1,'int32');
 184 header.e_ehsize=fread(fid,1,'int16');
 185 header.e_phentsize=fread(fid,1,'int16');
 186 header.e_phnum=fread(fid,1,'int16');
 187 header.e_shentsize=fread(fid,1,'int16');
 188 header.e_shnum=fread(fid,1,'int16');
 189 header.e_shstrndx=fread(fid,1,'int16');
 190 switch header.e_type
 191         case 0
 192                 header.typestr = 'none';
 193         case 1
 194                 header.typestr = 'relocatable';
 195         case 2
 196                 header.typestr = 'executable';
 197         case 3
 198                 header.typestr = 'shared object-file';
 199         case 4
 200                 header.typestr = 'core dump';
 201         otherwise
 202                 header.typestr = 'unknown';
 203 end
 204 switch header.e_machine
 205         case 0
 206                 header.machinestr = 'none';
 207         case 1
 208                 header.machinestr = 'at&t we 32100';
 209         case 2
 210                 header.machinestr = 'SPARC';
 211         case 3
 212                 header.machinestr = 'Intel';
 213         case 4
 214                 header.machinestr = 'M68000';
 215         case 5
 216                 header.machinestr = 'M88000';
 217         case 7
 218                 header.machinestr = 'i80860';
 219         case 8
 220                 header.machinestr = 'MIPS RS3000 Big-Endian';
 221         case 10
 222                 header.machinestr = 'MIPS RS4000 Little-Endian';
 223         case {11,12,13,14,15,16}
 224                 header.machinestr = 'reserved';
 225         otherwise
 226                 header.machinestr = 'unknown';
 227 end
 228 switch header.e_version
 229         case 0
 230                 header.versionstr = 'invalid';
 231         case 1
 232                 header.versionstr = 'current';
 233         otherwise
 234                 header.versionstr = 'unknown';
 235 end
 236 if all(header.e_ident(1:4)==[0x7f 'ELF']')
 237         header.magicstate = 'ok';
 238 else
 239         header.magicstate = 'invalid';
 240 end
 241 switch header.e_ident(5)
 242         case 0
 243                 header.classstr = 'invalid';
 244         case 1
 245                 header.classstr = '32bit';
 246         case 2
 247                 header.classstr = '64bit';
 248         otherwise
 249                 header.versionstr = 'unknown';
 250 end
 251 switch header.e_ident(6)
 252         case 0
 253                 header.datastr = 'invalid';
 254         case 1
 255                 header.datastr = 'lsb';
 256         case 2
 257                 header.datastr = 'msb';
 258         otherwise
 259                 header.versionstr = 'unknown';
 260 end