1 /* -*- sh -*- */ 2 3 /* 4 * Linker script for i386 images 5 * 6 */ 7 8 OUTPUT_FORMAT ( "elf32-i386", "elf32-i386", "elf32-i386" ) 9 OUTPUT_ARCH ( i386 ) 10 ENTRY ( _entry ) 11 12 SECTIONS { 13 14 /* All sections in the resulting file have consecutive load 15 * addresses, but may have individual link addresses depending on 16 * the memory model being used. 17 * 18 * The linker symbols _prefix_link_addr, load_addr, and 19 * _max_align may be specified explicitly. If not specified, they 20 * will default to: 21 * 22 * _prefix_link_addr = 0 23 * _load_addr = 0 24 * _max_align = 16 25 * 26 * We guarantee alignment of virtual addresses to any alignment 27 * specified by the constituent object files (e.g. via 28 * __attribute__((aligned(x)))). Load addresses are guaranteed 29 * only up to _max_align. Provided that all loader and relocation 30 * code honours _max_align, this means that physical addresses are 31 * also guaranteed up to _max_align. 32 * 33 * Note that when using -DKEEP_IT_REAL, the UNDI segments are only 34 * guaranteed to be loaded on a paragraph boundary (i.e. 16-byte 35 * alignment). Using _max_align>16 will therefore not guarantee 36 * >16-byte alignment of physical addresses when -DKEEP_IT_REAL is 37 * used (though virtual addresses will still be fully aligned). 38 * 39 */ 40 41 /* 42 * The prefix 43 */ 44 45 _prefix_link_addr = DEFINED ( _prefix_link_addr ) ? _prefix_link_addr : 0; 46 . = _prefix_link_addr; 47 _prefix = .; 48 49 .prefix : AT ( _prefix_load_offset + __prefix ) { 50 __prefix = .; 51 _entry = .; 52 *(.prefix) 53 *(.prefix.*) 54 _eprefix_progbits = .; 55 } 56 57 _eprefix = .; 58 59 /* 60 * The 16-bit sections 61 */ 62 63 _text16_link_addr = 0; 64 . = _text16_link_addr; 65 _text16 = .; 66 67 . += 1; /* Prevent NULL being valid */ 68 69 .text16 : AT ( _text16_load_offset + __text16 ) { 70 __text16 = .; 71 *(.text.null_trap) 72 *(.text16) 73 *(.text16.*) 74 *(.text) 75 *(.text.*) 76 _etext16_progbits = .; 77 } = 0x9090 78 79 _etext16 = .; 80 81 _data16_link_addr = 0; 82 . = _data16_link_addr; 83 _data16 = .; 84 85 . += 1; /* Prevent NULL being valid */ 86 87 .rodata16 : AT ( _data16_load_offset + __rodata16 ) { 88 __rodata16 = .; 89 *(.rodata16) 90 *(.rodata16.*) 91 *(.rodata) 92 *(.rodata.*) 93 } 94 .data16 : AT ( _data16_load_offset + __data16 ) { 95 __data16 = .; 96 *(.data16) 97 *(.data16.*) 98 *(.data) 99 *(.data.*) 100 *(SORT(.tbl.*)) /* Various tables. See include/tables.h */ 101 _edata16_progbits = .; 102 } 103 .bss16 : AT ( _data16_load_offset + __bss16 ) { 104 __bss16 = .; 105 _bss16 = .; 106 *(.bss16) 107 *(.bss16.*) 108 *(.bss) 109 *(.bss.*) 110 *(COMMON) 111 _ebss16 = .; 112 } 113 .stack16 : AT ( _data16_load_offset + __stack16 ) { 114 __stack16 = .; 115 *(.stack16) 116 *(.stack16.*) 117 *(.stack) 118 *(.stack.*) 119 } 120 121 _edata16 = .; 122 123 _end = .; 124 125 /* 126 * Dispose of the comment and note sections to make the link map 127 * easier to read 128 */ 129 130 /DISCARD/ : { 131 *(.comment) 132 *(.note) 133 *(.discard) 134 } 135 136 /* 137 * Load address calculations. The slightly obscure nature of the 138 * calculations is because ALIGN(x) can only operate on the 139 * location counter. 140 */ 141 142 _max_align = DEFINED ( _max_align ) ? _max_align : 16; 143 _load_addr = DEFINED ( _load_addr ) ? _load_addr : 0; 144 145 . = _load_addr; 146 147 . -= _prefix_link_addr; 148 _prefix_load_offset = ALIGN ( _max_align ); 149 _prefix_load_addr = _prefix_link_addr + _prefix_load_offset; 150 _prefix_size = _eprefix - _prefix; 151 _prefix_progbits_size = _eprefix_progbits - _prefix; 152 . = _prefix_load_addr + _prefix_progbits_size; 153 154 . -= _text16_link_addr; 155 _text16_load_offset = ALIGN ( _max_align ); 156 _text16_load_addr = _text16_link_addr + _text16_load_offset; 157 _text16_size = _etext16 - _text16; 158 _text16_progbits_size = _etext16_progbits - _text16; 159 . = _text16_load_addr + _text16_progbits_size; 160 161 . -= _data16_link_addr; 162 _data16_load_offset = ALIGN ( _max_align ); 163 _data16_load_addr = _data16_link_addr + _data16_load_offset; 164 _data16_size = _edata16 - _data16; 165 _data16_progbits_size = _edata16_progbits - _data16; 166 . = _data16_load_addr + _data16_progbits_size; 167 168 . = ALIGN ( _max_align ); 169 170 _load_size = . - _load_addr; 171 172 /* 173 * Alignment checks. ALIGN() can only operate on the location 174 * counter, so we set the location counter to each value we want 175 * to check. 176 */ 177 178 . = _prefix_load_addr - _prefix_link_addr; 179 _assert = ASSERT ( ( . == ALIGN ( _max_align ) ), 180 "_prefix is badly aligned" ); 181 182 . = _text16_load_addr - _text16_link_addr; 183 _assert = ASSERT ( ( . == ALIGN ( _max_align ) ), 184 "_text16 is badly aligned" ); 185 186 . = _data16_load_addr - _data16_link_addr; 187 _assert = ASSERT ( ( . == ALIGN ( _max_align ) ), 188 "_data16 is badly aligned" ); 189 190 /* 191 * Values calculated to save code from doing it 192 */ 193 _text16_size_pgh = ( ( _text16_size + 15 ) / 16 ); 194 _data16_size_pgh = ( ( _data16_size + 15 ) / 16 ); 195 _load_size_pgh = ( ( _load_size + 15 ) / 16 ); 196 _load_size_sect = ( ( _load_size + 511 ) / 512 ); 197 } 198
