linux/arch/x86/kernel/vmlinux.lds.S
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   1/*
   2 * ld script for the x86 kernel
   3 *
   4 * Historic 32-bit version written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>
   5 *
   6 * Modernisation, unification and other changes and fixes:
   7 *   Copyright (C) 2007-2009  Sam Ravnborg <sam@ravnborg.org>
   8 *
   9 *
  10 * Don't define absolute symbols until and unless you know that symbol
  11 * value is should remain constant even if kernel image is relocated
  12 * at run time. Absolute symbols are not relocated. If symbol value should
  13 * change if kernel is relocated, make the symbol section relative and
  14 * put it inside the section definition.
  15 */
  16
  17#ifdef CONFIG_X86_32
  18#define LOAD_OFFSET __PAGE_OFFSET
  19#else
  20#define LOAD_OFFSET __START_KERNEL_map
  21#endif
  22
  23#include <asm-generic/vmlinux.lds.h>
  24#include <asm/asm-offsets.h>
  25#include <asm/thread_info.h>
  26#include <asm/page_types.h>
  27#include <asm/cache.h>
  28#include <asm/boot.h>
  29
  30#undef i386     /* in case the preprocessor is a 32bit one */
  31
  32OUTPUT_FORMAT(CONFIG_OUTPUT_FORMAT, CONFIG_OUTPUT_FORMAT, CONFIG_OUTPUT_FORMAT)
  33
  34#ifdef CONFIG_X86_32
  35OUTPUT_ARCH(i386)
  36ENTRY(phys_startup_32)
  37jiffies = jiffies_64;
  38#else
  39OUTPUT_ARCH(i386:x86-64)
  40ENTRY(phys_startup_64)
  41jiffies_64 = jiffies;
  42#endif
  43
  44PHDRS {
  45        text PT_LOAD FLAGS(5);          /* R_E */
  46        data PT_LOAD FLAGS(7);          /* RWE */
  47#ifdef CONFIG_X86_64
  48        user PT_LOAD FLAGS(5);          /* R_E */
  49#ifdef CONFIG_SMP
  50        percpu PT_LOAD FLAGS(6);        /* RW_ */
  51#endif
  52        init PT_LOAD FLAGS(7);          /* RWE */
  53#endif
  54        note PT_NOTE FLAGS(0);          /* ___ */
  55}
  56
  57SECTIONS
  58{
  59#ifdef CONFIG_X86_32
  60        . = LOAD_OFFSET + LOAD_PHYSICAL_ADDR;
  61        phys_startup_32 = startup_32 - LOAD_OFFSET;
  62#else
  63        . = __START_KERNEL;
  64        phys_startup_64 = startup_64 - LOAD_OFFSET;
  65#endif
  66
  67        /* Text and read-only data */
  68        .text :  AT(ADDR(.text) - LOAD_OFFSET) {
  69                _text = .;
  70                /* bootstrapping code */
  71                HEAD_TEXT
  72#ifdef CONFIG_X86_32
  73                . = ALIGN(PAGE_SIZE);
  74                *(.text.page_aligned)
  75#endif
  76                . = ALIGN(8);
  77                _stext = .;
  78                TEXT_TEXT
  79                SCHED_TEXT
  80                LOCK_TEXT
  81                KPROBES_TEXT
  82                IRQENTRY_TEXT
  83                *(.fixup)
  84                *(.gnu.warning)
  85                /* End of text section */
  86                _etext = .;
  87        } :text = 0x9090
  88
  89        NOTES :text :note
  90
  91        EXCEPTION_TABLE(16) :text = 0x9090
  92
  93        RO_DATA(PAGE_SIZE)
  94
  95        /* Data */
  96        .data : AT(ADDR(.data) - LOAD_OFFSET) {
  97                /* Start of data section */
  98                _sdata = .;
  99
 100                /* init_task */
 101                INIT_TASK_DATA(THREAD_SIZE)
 102
 103#ifdef CONFIG_X86_32
 104                /* 32 bit has nosave before _edata */
 105                NOSAVE_DATA
 106#endif
 107
 108                PAGE_ALIGNED_DATA(PAGE_SIZE)
 109
 110                CACHELINE_ALIGNED_DATA(CONFIG_X86_L1_CACHE_BYTES)
 111
 112                DATA_DATA
 113                CONSTRUCTORS
 114
 115                /* rarely changed data like cpu maps */
 116                READ_MOSTLY_DATA(CONFIG_X86_INTERNODE_CACHE_BYTES)
 117
 118                /* End of data section */
 119                _edata = .;
 120        } :data
 121
 122#ifdef CONFIG_X86_64
 123
 124#define VSYSCALL_ADDR (-10*1024*1024)
 125
 126#define VLOAD_OFFSET (VSYSCALL_ADDR - __vsyscall_0 + LOAD_OFFSET)
 127#define VLOAD(x) (ADDR(x) - VLOAD_OFFSET)
 128
 129#define VVIRT_OFFSET (VSYSCALL_ADDR - __vsyscall_0)
 130#define VVIRT(x) (ADDR(x) - VVIRT_OFFSET)
 131
 132        . = ALIGN(4096);
 133        __vsyscall_0 = .;
 134
 135        . = VSYSCALL_ADDR;
 136        .vsyscall_0 : AT(VLOAD(.vsyscall_0)) {
 137                *(.vsyscall_0)
 138        } :user
 139
 140        . = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
 141        .vsyscall_fn : AT(VLOAD(.vsyscall_fn)) {
 142                *(.vsyscall_fn)
 143        }
 144
 145        . = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
 146        .vsyscall_gtod_data : AT(VLOAD(.vsyscall_gtod_data)) {
 147                *(.vsyscall_gtod_data)
 148        }
 149
 150        vsyscall_gtod_data = VVIRT(.vsyscall_gtod_data);
 151        .vsyscall_clock : AT(VLOAD(.vsyscall_clock)) {
 152                *(.vsyscall_clock)
 153        }
 154        vsyscall_clock = VVIRT(.vsyscall_clock);
 155
 156
 157        .vsyscall_1 ADDR(.vsyscall_0) + 1024: AT(VLOAD(.vsyscall_1)) {
 158                *(.vsyscall_1)
 159        }
 160        .vsyscall_2 ADDR(.vsyscall_0) + 2048: AT(VLOAD(.vsyscall_2)) {
 161                *(.vsyscall_2)
 162        }
 163
 164        .vgetcpu_mode : AT(VLOAD(.vgetcpu_mode)) {
 165                *(.vgetcpu_mode)
 166        }
 167        vgetcpu_mode = VVIRT(.vgetcpu_mode);
 168
 169        . = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
 170        .jiffies : AT(VLOAD(.jiffies)) {
 171                *(.jiffies)
 172        }
 173        jiffies = VVIRT(.jiffies);
 174
 175        .vsyscall_3 ADDR(.vsyscall_0) + 3072: AT(VLOAD(.vsyscall_3)) {
 176                *(.vsyscall_3)
 177        }
 178
 179        . = __vsyscall_0 + PAGE_SIZE;
 180
 181#undef VSYSCALL_ADDR
 182#undef VLOAD_OFFSET
 183#undef VLOAD
 184#undef VVIRT_OFFSET
 185#undef VVIRT
 186
 187#endif /* CONFIG_X86_64 */
 188
 189        /* Init code and data - will be freed after init */
 190        . = ALIGN(PAGE_SIZE);
 191        .init.begin : AT(ADDR(.init.begin) - LOAD_OFFSET) {
 192                __init_begin = .; /* paired with __init_end */
 193        }
 194
 195#if defined(CONFIG_X86_64) && defined(CONFIG_SMP)
 196        /*
 197         * percpu offsets are zero-based on SMP.  PERCPU_VADDR() changes the
 198         * output PHDR, so the next output section - .init.text - should
 199         * start another segment - init.
 200         */
 201        PERCPU_VADDR(0, :percpu)
 202#endif
 203
 204        INIT_TEXT_SECTION(PAGE_SIZE)
 205#ifdef CONFIG_X86_64
 206        :init
 207#endif
 208
 209        INIT_DATA_SECTION(16)
 210
 211        .x86_cpu_dev.init : AT(ADDR(.x86_cpu_dev.init) - LOAD_OFFSET) {
 212                __x86_cpu_dev_start = .;
 213                *(.x86_cpu_dev.init)
 214                __x86_cpu_dev_end = .;
 215        }
 216
 217        . = ALIGN(8);
 218        .parainstructions : AT(ADDR(.parainstructions) - LOAD_OFFSET) {
 219                __parainstructions = .;
 220                *(.parainstructions)
 221                __parainstructions_end = .;
 222        }
 223
 224        . = ALIGN(8);
 225        .altinstructions : AT(ADDR(.altinstructions) - LOAD_OFFSET) {
 226                __alt_instructions = .;
 227                *(.altinstructions)
 228                __alt_instructions_end = .;
 229        }
 230
 231        .altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) {
 232                *(.altinstr_replacement)
 233        }
 234
 235        /*
 236         * .exit.text is discard at runtime, not link time, to deal with
 237         *  references from .altinstructions and .eh_frame
 238         */
 239        .exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) {
 240                EXIT_TEXT
 241        }
 242
 243        .exit.data : AT(ADDR(.exit.data) - LOAD_OFFSET) {
 244                EXIT_DATA
 245        }
 246
 247#if !defined(CONFIG_X86_64) || !defined(CONFIG_SMP)
 248        PERCPU(PAGE_SIZE)
 249#endif
 250
 251        . = ALIGN(PAGE_SIZE);
 252
 253        /* freed after init ends here */
 254        .init.end : AT(ADDR(.init.end) - LOAD_OFFSET) {
 255                __init_end = .;
 256        }
 257
 258        /*
 259         * smp_locks might be freed after init
 260         * start/end must be page aligned
 261         */
 262        . = ALIGN(PAGE_SIZE);
 263        .smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) {
 264                __smp_locks = .;
 265                *(.smp_locks)
 266                __smp_locks_end = .;
 267                . = ALIGN(PAGE_SIZE);
 268        }
 269
 270#ifdef CONFIG_X86_64
 271        .data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {
 272                NOSAVE_DATA
 273        }
 274#endif
 275
 276        /* BSS */
 277        . = ALIGN(PAGE_SIZE);
 278        .bss : AT(ADDR(.bss) - LOAD_OFFSET) {
 279                __bss_start = .;
 280                *(.bss.page_aligned)
 281                *(.bss)
 282                . = ALIGN(4);
 283                __bss_stop = .;
 284        }
 285
 286        . = ALIGN(PAGE_SIZE);
 287        .brk : AT(ADDR(.brk) - LOAD_OFFSET) {
 288                __brk_base = .;
 289                . += 64 * 1024;         /* 64k alignment slop space */
 290                *(.brk_reservation)     /* areas brk users have reserved */
 291                __brk_limit = .;
 292        }
 293
 294        .end : AT(ADDR(.end) - LOAD_OFFSET) {
 295                _end = .;
 296        }
 297
 298        STABS_DEBUG
 299        DWARF_DEBUG
 300
 301        /* Sections to be discarded */
 302        DISCARDS
 303        /DISCARD/ : { *(.eh_frame) }
 304}
 305
 306
 307#ifdef CONFIG_X86_32
 308/*
 309 * The ASSERT() sink to . is intentional, for binutils 2.14 compatibility:
 310 */
 311. = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE),
 312           "kernel image bigger than KERNEL_IMAGE_SIZE");
 313#else
 314/*
 315 * Per-cpu symbols which need to be offset from __per_cpu_load
 316 * for the boot processor.
 317 */
 318#define INIT_PER_CPU(x) init_per_cpu__##x = per_cpu__##x + __per_cpu_load
 319INIT_PER_CPU(gdt_page);
 320INIT_PER_CPU(irq_stack_union);
 321
 322/*
 323 * Build-time check on the image size:
 324 */
 325. = ASSERT((_end - _text <= KERNEL_IMAGE_SIZE),
 326           "kernel image bigger than KERNEL_IMAGE_SIZE");
 327
 328#ifdef CONFIG_SMP
 329. = ASSERT((per_cpu__irq_stack_union == 0),
 330           "irq_stack_union is not at start of per-cpu area");
 331#endif
 332
 333#endif /* CONFIG_X86_32 */
 334
 335#ifdef CONFIG_KEXEC
 336#include <asm/kexec.h>
 337
 338. = ASSERT(kexec_control_code_size <= KEXEC_CONTROL_CODE_MAX_SIZE,
 339           "kexec control code size is too big");
 340#endif
 341
 342