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1 /* ================================================================= |
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2 * |
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3 * objelf.c |
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4 * |
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5 * Relocation routine for eCos loader. |
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6 * |
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7 * ================================================================= |
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8 * ####ECOSGPLCOPYRIGHTBEGIN#### |
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9 * ------------------------------------------- |
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10 * This file is part of eCos, the Embedded Configurable Operating |
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11 * System. |
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12 * Copyright (C) 2005 eCosCentric Ltd. |
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13 * |
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14 * eCos is free software; you can redistribute it and/or modify it |
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15 * under the terms of the GNU General Public License as published by |
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16 * the Free Software Foundation; either version 2 or (at your option) |
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17 * any later version. |
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18 * |
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19 * eCos is distributed in the hope that it will be useful, but |
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20 * WITHOUT ANY WARRANTY; without even the implied warranty of |
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21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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22 * General Public License for more details. |
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23 * |
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24 * You should have received a copy of the GNU General Public License |
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25 * along with eCos; if not, write to the Free Software Foundation, |
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26 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. |
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27 * |
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28 * As a special exception, if other files instantiate templates or |
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29 * use macros or inline functions from this file, or you compile this |
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30 * file and link it with other works to produce a work based on this |
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31 * file, this file does not by itself cause the resulting work to be |
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32 * covered by the GNU General Public License. However the source code |
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33 * for this file must still be made available in accordance with |
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34 * section (3) of the GNU General Public License. |
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35 * |
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36 * This exception does not invalidate any other reasons why a work |
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37 * based on this file might be covered by the GNU General Public |
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38 * License. |
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39 * |
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40 * ------------------------------------------- |
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41 * ####ECOSGPLCOPYRIGHTEND#### |
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42 * ================================================================= |
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43 * #####DESCRIPTIONBEGIN#### |
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44 * |
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45 * Author(s): atonizzo@lycos.com |
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46 * Contributors: nickg@ecoscentric.com |
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47 * Date: 2005-05-13 |
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48 * Purpose: |
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49 * Description: |
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50 * |
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51 * ####DESCRIPTIONEND#### |
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52 * |
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53 * ================================================================= |
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54 */ |
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55 |
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56 #include <cyg/infra/diag.h> // For diagnostic printing. |
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57 #include <pkgconf/io_fileio.h> |
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58 #include <cyg/hal/hal_tables.h> |
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59 #include <stdio.h> |
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60 |
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61 #include <pkgconf/objloader.h> |
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62 #include <cyg/objloader/elf.h> |
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63 #include <cyg/objloader/objelf.h> |
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64 |
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65 CYG_HAL_TABLE_BEGIN( cyg_ldr_table, ldr_table ); |
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66 CYG_HAL_TABLE_END( cyg_ldr_table_end, ldr_table ); |
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67 |
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68 __externC cyg_ldr_table_entry cyg_ldr_table[]; |
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69 __externC cyg_ldr_table_entry cyg_ldr_table_end[]; |
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70 |
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71 #if CYGPKG_SERVICES_OBJLOADER_DEBUG_LEVEL > 0 |
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72 void |
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73 cyg_ldr_print_section_data( PELF_OBJECT p ) |
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74 { |
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75 cyg_int32 i; |
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76 cyg_uint8 strname[32]; |
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77 cyg_uint8 *p_strtab = (cyg_uint8*)p->sections[p->p_elfhdr->e_shstrndx]; |
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78 |
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79 diag_printf( "\n\nSection Headers:\n" ); |
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80 diag_printf( "[Nr] Name Addr Offset Size Info\n" ); |
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81 for ( i = 0; i < p->p_elfhdr->e_shnum; i++ ) |
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82 { |
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83 sprintf( strname, "%s", p_strtab + p->p_sechdr[i].sh_name ); |
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84 while ( strlen( strname ) < 20 ) |
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85 strcat( strname, " " ); |
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86 diag_printf( "[%02d] %s %08X %08X %08X %08X\n", |
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87 i, |
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88 strname, |
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89 p->p_sechdr[i].sh_addr, |
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90 p->p_sechdr[i].sh_offset, |
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91 p->p_sechdr[i].sh_size, |
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92 p->p_sechdr[i].sh_info ); |
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93 } |
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94 diag_printf( "\n" ); |
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95 } |
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96 |
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97 void |
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98 cyg_ldr_print_symbol_names( PELF_OBJECT p ) |
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99 { |
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100 cyg_int32 i, symtab_entries; |
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101 Elf32_Sym *p_symtab = (Elf32_Sym*)p->sections[p->hdrndx_symtab]; |
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102 cyg_uint8 *p_strtab = (cyg_uint8*)p->sections[p->hdrndx_strtab]; |
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103 cyg_uint8 strname[32]; |
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104 |
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105 // Total number of entries in the symbol table. |
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106 symtab_entries = p->p_sechdr[p->hdrndx_symtab].sh_size / |
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107 p->p_sechdr[p->hdrndx_symtab].sh_entsize; |
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108 diag_printf( "Num Value Size Ndx Name\n" ); |
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109 for ( i = 1; i < symtab_entries; i++ ) |
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110 { |
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111 sprintf( strname, "%d", i ); |
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112 while ( strlen( strname ) < 5 ) |
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113 strcat( strname, " " ); |
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114 diag_printf( strname ); |
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115 |
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116 sprintf( strname, |
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117 "%08X %d", |
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118 p_symtab[i].st_value, |
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119 p_symtab[i].st_size ); |
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120 while ( strlen( strname ) < 15 ) |
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121 strcat( strname, " " ); |
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122 diag_printf( strname ); |
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123 |
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124 sprintf( strname, "%d", p_symtab[i].st_shndx ); |
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125 while ( strlen( strname ) < 6 ) |
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126 strcat( strname, " " ); |
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127 diag_printf( strname ); |
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128 |
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129 strncpy( strname, |
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130 p_strtab + p_symtab[i].st_name, |
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131 sizeof( strname ) - 1 ); |
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132 strname[strlen( p_strtab + p_symtab[i].st_name )] = '\0'; |
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133 diag_printf( strname ); |
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134 diag_printf( "\n" ); |
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135 } |
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136 } |
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137 |
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138 void |
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139 cyg_ldr_print_rel_names( PELF_OBJECT p ) |
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140 { |
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141 cyg_int32 i, j, r_entries, sym_index; |
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142 Elf32_Sym *p_symtab = (Elf32_Sym*)p->sections[p->hdrndx_symtab]; |
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143 cyg_uint8 *p_strtab = (cyg_uint8*)p->sections[p->hdrndx_strtab]; |
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144 cyg_uint8 *p_shstrtab = (cyg_uint8*)p->sections[p->p_elfhdr->e_shstrndx]; |
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145 #if ELF_ARCH_RELTYPE == Elf_Rela |
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146 Elf32_Rela* p_rela; |
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147 #else |
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148 Elf32_Rel* p_rel; |
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149 #endif |
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150 cyg_uint8 strname[32]; |
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151 |
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152 for ( i = 1; i < p->p_elfhdr->e_shnum; i++ ) |
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153 { |
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154 if ( ( p->p_sechdr[i].sh_type == SHT_REL ) || |
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155 ( p->p_sechdr[i].sh_type == SHT_RELA ) ) |
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156 { |
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157 // Calculate the total number of entries in the .rela section. |
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158 r_entries = p->p_sechdr[i].sh_size / p->p_sechdr[i].sh_entsize; |
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159 |
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160 diag_printf( "\n\nSymbols at: %s\n\n", |
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161 p_shstrtab + p->p_sechdr[i].sh_name ); |
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162 #if ELF_ARCH_RELTYPE == Elf_Rela |
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163 p_rela = (Elf32_Rela*)cyg_ldr_load_elf_section( p, i ); |
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164 printf( "Offset Info Name [+ Addend]\n" ); |
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165 #else |
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166 p_rel = (Elf32_Rel*)cyg_ldr_load_elf_section( p, i ); |
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167 printf( "Offset Info Name\n" ); |
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168 #endif |
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169 |
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170 for ( j = 0; j < r_entries; j++ ) |
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171 { |
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172 sprintf( strname, |
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173 "%08X %08X ", |
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174 p_rela[j].r_offset, |
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175 p_rela[j].r_info ); |
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176 |
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177 diag_printf( strname ); |
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178 |
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179 cyg_uint8 sym_type = ELF32_R_SYM( p_rela[j].r_info ); |
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180 if ( strlen ( p_strtab + p_symtab[sym_type].st_name ) > 0 ) |
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181 diag_printf( p_strtab + p_symtab[sym_type].st_name ); |
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182 else |
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183 { |
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184 // If the symbol name is not available, then print |
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185 // the name of the section. |
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186 sym_index = p_symtab[sym_type].st_shndx; |
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187 diag_printf( p_shstrtab + p->p_sechdr[sym_index].sh_name ); |
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188 } |
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189 #if ELF_ARCH_RELTYPE == Elf_Rela |
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190 if ( p_rela[j].r_addend != 0 ) |
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191 diag_printf( " + %08X", p_rela[j].r_addend ); |
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192 #endif |
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193 diag_printf( "\n" ); |
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194 } |
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195 // After all the printing is done, the relocation table can |
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196 // be dumped. |
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197 cyg_ldr_delete_elf_section( p, i ); |
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198 } |
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199 } |
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200 } |
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201 #endif // DEBUG_PRINT |
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202 |
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203 static void |
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204 *cyg_ldr_local_address( PELF_OBJECT p, cyg_uint32 sym_index ) |
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205 { |
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206 cyg_uint32 data_sec, addr; |
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207 Elf32_Sym *p_symtab; |
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208 |
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209 p_symtab = (Elf32_Sym*)cyg_ldr_section_address( p, p->hdrndx_symtab ); |
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210 |
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211 // Find out the section number in which the data for this symbol is |
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212 // located. |
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213 data_sec = p_symtab[sym_index].st_shndx; |
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214 |
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215 // From the section number we get the start of the memory area in |
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216 // memory. |
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217 addr = (cyg_uint32)cyg_ldr_section_address( p, data_sec ); |
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218 |
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219 // And now return the address of the data. |
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220 return (void*)( addr + p_symtab[sym_index].st_value); |
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221 } |
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222 |
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223 static void |
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224 *cyg_ldr_external_address( PELF_OBJECT p, cyg_uint32 sym_index ) |
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225 { |
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226 cyg_uint8* tmp2; |
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227 Elf32_Sym *p_symtab; |
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228 cyg_uint8 *p_strtab; |
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229 cyg_ldr_table_entry *entry = cyg_ldr_table; |
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230 |
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231 |
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232 p_symtab = (Elf32_Sym*)cyg_ldr_section_address( p, p->hdrndx_symtab ); |
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233 p_strtab = (cyg_uint8*)cyg_ldr_section_address( p, p->hdrndx_strtab ); |
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234 |
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235 // This is the name of the external reference to search. |
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236 tmp2 = p_strtab + p_symtab[sym_index].st_name; |
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237 while ( entry != cyg_ldr_table_end ) |
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238 { |
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239 if ( !strcmp( (const char*)tmp2, entry->symbol_name ) ) |
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240 return entry->handler; |
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241 entry++; |
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242 } |
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243 |
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244 // Symbol not found. |
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245 return 0; |
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246 } |
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247 |
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248 // input: |
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249 // p : Pointer to the elf file object |
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250 // sym_index : Index of the symbol to be searched (in the SYMTAB) |
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251 // |
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252 // out: |
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253 // 0 : Symbol not found |
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254 // Other : Address of the symbol in absolute memory. |
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255 void |
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256 *cyg_ldr_symbol_address( PELF_OBJECT p, cyg_uint32 sym_index ) |
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257 { |
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258 cyg_uint32 addr; |
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259 cyg_uint8 sym_info; |
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260 Elf32_Sym *p_symtab; |
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261 |
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262 p_symtab = (Elf32_Sym*)cyg_ldr_section_address( p, p->hdrndx_symtab ); |
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263 sym_info = p_symtab[sym_index].st_info; |
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264 |
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265 switch ( ELF32_ST_TYPE( sym_info ) ) |
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266 { |
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267 case STT_NOTYPE: |
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268 case STT_FUNC: |
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269 case STT_OBJECT: |
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270 switch ( ELF32_ST_BIND( sym_info ) ) |
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271 { |
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272 case STB_LOCAL: |
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273 case STB_GLOBAL: |
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274 if ( p_symtab[sym_index].st_shndx == SHN_UNDEF ) |
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275 return cyg_ldr_external_address( p, sym_index ); |
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276 else |
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277 return cyg_ldr_local_address( p, sym_index ); |
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278 case STB_WEAK: |
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279 addr = (cyg_uint32)cyg_ldr_external_address( p, sym_index ); |
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280 if ( addr != 0 ) |
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281 return (void*)addr; |
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282 else |
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283 return cyg_ldr_local_address( p, sym_index ); |
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284 default: |
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285 return 0; |
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286 } |
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287 break; |
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288 case STT_SECTION: |
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289 // Return the starting address of a section, given its index. |
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290 return (void*)cyg_ldr_section_address( p, |
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291 p_symtab[sym_index].st_shndx ); |
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292 default: |
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293 return 0; |
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294 } |
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295 } |
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296 |
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297 // Loads the relocation information, relocates, and dumps the relocation |
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298 // information once the process is complete. |
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299 cyg_int32 |
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300 cyg_ldr_relocate_section( PELF_OBJECT p, cyg_uint32 r_shndx ) |
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301 { |
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302 cyg_int32 i, rc; |
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303 cyg_uint32 r_entries, r_target_shndx, r_target_addr; |
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304 cyg_uint32 sym_value, sym_index; |
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305 Elf32_Addr r_offset; |
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306 Elf32_Word r_type; |
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307 Elf32_Sword r_addend; |
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308 #if ELF_ARCH_RELTYPE == Elf_Rela |
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309 Elf32_Rela* p_rela = (Elf32_Rela*)cyg_ldr_load_elf_section( p, r_shndx ); |
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310 #else |
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311 Elf32_Rel* p_rel = (Elf32_Rel*)cyg_ldr_load_elf_section( p, r_shndx ); |
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312 #endif |
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313 |
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314 #if CYGPKG_SERVICES_OBJLOADER_DEBUG_LEVEL > 0 |
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315 Elf32_Sym *p_symtab = (Elf32_Sym*)cyg_ldr_section_address( p, |
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316 p->hdrndx_symtab ); |
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317 cyg_uint8 *p_strtab = (cyg_uint8*)cyg_ldr_section_address( p, |
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318 p->hdrndx_strtab ); |
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319 cyg_uint8 *p_shstrtab = (cyg_uint8*)cyg_ldr_section_address( p, |
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320 p->p_elfhdr->e_shstrndx ); |
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321 #endif |
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322 |
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323 // Now we can get the address of the contents of the section to modify. |
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324 r_target_shndx = p->p_sechdr[r_shndx].sh_info; |
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325 r_target_addr = (cyg_uint32)cyg_ldr_section_address( p, r_target_shndx ); |
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326 |
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327 #if CYGPKG_SERVICES_OBJLOADER_DEBUG_LEVEL > 0 |
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328 diag_printf( "Relocating section \"%s\"\n", |
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329 p_shstrtab + p->p_sechdr[r_target_shndx].sh_name ); |
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330 #if CYGPKG_SERVICES_OBJLOADER_DEBUG_LEVEL > 1 |
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331 diag_printf( "Ndx Type Offset Name\"\n" ); |
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332 #endif |
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333 #endif |
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334 |
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335 // Perform relocatation for each of the members of this table. |
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336 r_entries = p->p_sechdr[r_shndx].sh_size / p->p_sechdr[r_shndx].sh_entsize; |
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337 for ( i = 0; i < r_entries; i++ ) |
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338 { |
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339 #if ELF_ARCH_RELTYPE == Elf_Rela |
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340 r_offset = p_rela[i].r_offset; |
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341 r_type = ELF32_R_TYPE( p_rela[i].r_info ); |
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342 sym_index = ELF32_R_SYM( p_rela[i].r_info ); |
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343 r_addend = p_rela[i].r_addend; |
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344 #else |
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345 r_offset = p_rel[i].r_offset; |
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346 r_type = ELF32_R_TYPE( p_rel[i].r_info ); |
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347 sym_index = ELF32_R_SYM( p_rel[i].r_info ); |
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348 r_addend = 0; |
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349 #endif |
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350 |
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351 sym_value = (cyg_uint32)cyg_ldr_symbol_address( p, sym_index ); |
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352 if ( sym_value == 0 ) |
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353 { |
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354 #if CYGPKG_SERVICES_OBJLOADER_DEBUG_LEVEL > 0 |
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355 diag_printf( "Unknown symbol value: %s Index: %d\n", |
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356 p_strtab + p_symtab[sym_index].st_name, |
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357 sym_index ); |
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358 #endif |
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359 return -1; |
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360 } |
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361 |
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362 // This is architecture dependent, and deals with whether we have |
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363 // '.rel' or '.rela' sections. |
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364 #if CYGPKG_SERVICES_OBJLOADER_DEBUG_LEVEL > 1 |
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365 diag_printf( "%04X %04X %08X ", |
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366 sym_index, |
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367 r_type, |
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368 r_offset ); |
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369 if ( strlen ( p_strtab + p_symtab[sym_index].st_name ) > 0 ) |
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370 diag_printf( p_strtab + p_symtab[sym_index].st_name ); |
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371 else |
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372 { |
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373 // If the symbol name is not available, then print |
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374 // the name of the section. |
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375 cyg_uint32 sec_ndx = p_symtab[sym_index].st_shndx; |
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376 diag_printf( p_shstrtab + p->p_sechdr[sec_ndx].sh_name ); |
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377 } |
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378 diag_printf( "\n" ); |
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379 #endif |
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380 rc = cyg_ldr_relocate( r_type, |
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381 r_target_addr + r_offset, |
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382 sym_value + r_addend ); |
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383 if ( rc != 0 ) |
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384 { |
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385 #if CYGPKG_SERVICES_OBJLOADER_DEBUG_LEVEL > 0 |
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386 diag_printf( "Relocation error: Cannot find symbol: %s\n", |
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387 p_strtab + p_symtab[sym_index].st_name ); |
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388 #endif |
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389 return -1; |
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390 } |
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391 } |
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392 |
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393 // After the relocation is done, the relocation table can be dumped. |
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394 cyg_ldr_delete_elf_section( p, r_shndx ); |
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395 return 0; |
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396 } |
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397 |
