arch/x86/kernel/vmlinux_32.lds.S

   1 /* ld script to make i386 Linux kernel
   2  * Written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>;
   3  *
   4  * Don't define absolute symbols until and unless you know that symbol
   5  * value is should remain constant even if kernel image is relocated
   6  * at run time. Absolute symbols are not relocated. If symbol value should
   7  * change if kernel is relocated, make the symbol section relative and
   8  * put it inside the section definition.
   9  */
  10
  11 #define LOAD_OFFSET __PAGE_OFFSET
  12
  13 #include <asm-generic/vmlinux.lds.h>
  14 #include <asm/thread_info.h>
  15 #include <asm/page_types.h>
  16 #include <asm/cache.h>
  17 #include <asm/boot.h>
  18
  19 OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386")
  20 OUTPUT_ARCH(i386)
  21 ENTRY(phys_startup_32)
  22 jiffies = jiffies_64;
  23
  24 PHDRS {
  25         text PT_LOAD FLAGS(5);  /* R_E */
  26         data PT_LOAD FLAGS(7);  /* RWE */
  27         note PT_NOTE FLAGS(0);  /* ___ */
  28 }
  29 SECTIONS
  30 {
  31   . = LOAD_OFFSET + LOAD_PHYSICAL_ADDR;
  32   phys_startup_32 = startup_32 - LOAD_OFFSET;
  33
  34   .text.head : AT(ADDR(.text.head) - LOAD_OFFSET) {
  35         _text = .;                      /* Text and read-only data */
  36         *(.text.head)
  37   } :text = 0x9090
  38
  39   /* read-only */
  40   .text : AT(ADDR(.text) - LOAD_OFFSET) {
  41         . = ALIGN(PAGE_SIZE); /* not really needed, already page aligned */
  42         *(.text.page_aligned)
  43         TEXT_TEXT
  44         SCHED_TEXT
  45         LOCK_TEXT
  46         KPROBES_TEXT
  47         IRQENTRY_TEXT
  48         *(.fixup)
  49         *(.gnu.warning)
  50         _etext = .;                     /* End of text section */
  51   } :text = 0x9090
  52
  53   NOTES :text :note
  54
  55   . = ALIGN(16);                /* Exception table */
  56   __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
  57         __start___ex_table = .;
  58          *(__ex_table)
  59         __stop___ex_table = .;
  60   } :text = 0x9090
  61
  62   RODATA
  63
  64   /* writeable */
  65   . = ALIGN(PAGE_SIZE);
  66   .data : AT(ADDR(.data) - LOAD_OFFSET) {       /* Data */
  67         DATA_DATA
  68         CONSTRUCTORS
  69         } :data
  70
  71   . = ALIGN(PAGE_SIZE);
  72   .data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {
  73         __nosave_begin = .;
  74         *(.data.nosave)
  75         . = ALIGN(PAGE_SIZE);
  76         __nosave_end = .;
  77   }
  78
  79   . = ALIGN(PAGE_SIZE);
  80   .data.page_aligned : AT(ADDR(.data.page_aligned) - LOAD_OFFSET) {
  81         *(.data.page_aligned)
  82         *(.data.idt)
  83   }
  84
  85   . = ALIGN(32);
  86   .data.cacheline_aligned : AT(ADDR(.data.cacheline_aligned) - LOAD_OFFSET) {
  87         *(.data.cacheline_aligned)
  88   }
  89
  90   /* rarely changed data like cpu maps */
  91   . = ALIGN(32);
  92   .data.read_mostly : AT(ADDR(.data.read_mostly) - LOAD_OFFSET) {
  93         *(.data.read_mostly)
  94         _edata = .;             /* End of data section */
  95   }
  96
  97   . = ALIGN(THREAD_SIZE);       /* init_task */
  98   .data.init_task : AT(ADDR(.data.init_task) - LOAD_OFFSET) {
  99         *(.data.init_task)
 100   }
 101
 102   /* might get freed after init */
 103   . = ALIGN(PAGE_SIZE);
 104   .smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) {
 105         __smp_locks = .;
 106         *(.smp_locks)
 107         __smp_locks_end = .;
 108   }
 109   /* will be freed after init
 110    * Following ALIGN() is required to make sure no other data falls on the
 111    * same page where __smp_alt_end is pointing as that page might be freed
 112    * after boot. Always make sure that ALIGN() directive is present after
 113    * the section which contains __smp_alt_end.
 114    */
 115   . = ALIGN(PAGE_SIZE);
 116
 117   /* will be freed after init */
 118   . = ALIGN(PAGE_SIZE);         /* Init code and data */
 119   .init.text : AT(ADDR(.init.text) - LOAD_OFFSET) {
 120         __init_begin = .;
 121         _sinittext = .;
 122         INIT_TEXT
 123         _einittext = .;
 124   }
 125   .init.data : AT(ADDR(.init.data) - LOAD_OFFSET) {
 126         INIT_DATA
 127   }
 128   . = ALIGN(16);
 129   .init.setup : AT(ADDR(.init.setup) - LOAD_OFFSET) {
 130         __setup_start = .;
 131         *(.init.setup)
 132         __setup_end = .;
 133    }
 134   .initcall.init : AT(ADDR(.initcall.init) - LOAD_OFFSET) {
 135         __initcall_start = .;
 136         INITCALLS
 137         __initcall_end = .;
 138   }
 139   .con_initcall.init : AT(ADDR(.con_initcall.init) - LOAD_OFFSET) {
 140         __con_initcall_start = .;
 141         *(.con_initcall.init)
 142         __con_initcall_end = .;
 143   }
 144   .x86_cpu_dev.init : AT(ADDR(.x86_cpu_dev.init) - LOAD_OFFSET) {
 145         __x86_cpu_dev_start = .;
 146         *(.x86_cpu_dev.init)
 147         __x86_cpu_dev_end = .;
 148   }
 149   SECURITY_INIT
 150   . = ALIGN(4);
 151   .altinstructions : AT(ADDR(.altinstructions) - LOAD_OFFSET) {
 152         __alt_instructions = .;
 153         *(.altinstructions)
 154         __alt_instructions_end = .;
 155   }
 156   .altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) {
 157         *(.altinstr_replacement)
 158   }
 159   . = ALIGN(4);
 160   .parainstructions : AT(ADDR(.parainstructions) - LOAD_OFFSET) {
 161         __parainstructions = .;
 162         *(.parainstructions)
 163         __parainstructions_end = .;
 164   }
 165   /* .exit.text is discard at runtime, not link time, to deal with references
 166      from .altinstructions and .eh_frame */
 167   .exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) {
 168         EXIT_TEXT
 169   }
 170   .exit.data : AT(ADDR(.exit.data) - LOAD_OFFSET) {
 171         EXIT_DATA
 172   }
 173 #if defined(CONFIG_BLK_DEV_INITRD)
 174   . = ALIGN(PAGE_SIZE);
 175   .init.ramfs : AT(ADDR(.init.ramfs) - LOAD_OFFSET) {
 176         __initramfs_start = .;
 177         *(.init.ramfs)
 178         __initramfs_end = .;
 179   }
 180 #endif
 181   PERCPU(PAGE_SIZE)
 182   . = ALIGN(PAGE_SIZE);
 183   /* freed after init ends here */
 184
 185   .bss : AT(ADDR(.bss) - LOAD_OFFSET) {
 186         __init_end = .;
 187         __bss_start = .;                /* BSS */
 188         *(.bss.page_aligned)
 189         *(.bss)
 190         . = ALIGN(4);
 191         __bss_stop = .;
 192
 193         . = ALIGN(PAGE_SIZE);
 194         __brk_base = . ;
 195         . += 64 * 1024 ;        /* 64k slop space */
 196         *(.brk_reservation)     /* areas brk users have reserved */
 197         __brk_limit = . ;
 198
 199         _end = . ;
 200   }
 201
 202   /* Sections to be discarded */
 203   /DISCARD/ : {
 204         *(.exitcall.exit)
 205         *(.discard)
 206         }
 207
 208   STABS_DEBUG
 209
 210   DWARF_DEBUG
 211 }
 212
 213 /*
 214  * Build-time check on the image size:
 215  */
 216 ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE),
 217         "kernel image bigger than KERNEL_IMAGE_SIZE")
 218
 219 #ifdef CONFIG_KEXEC
 220 /* Link time checks */
 221 #include <asm/kexec.h>
 222
 223 ASSERT(kexec_control_code_size <= KEXEC_CONTROL_CODE_MAX_SIZE,
 224        "kexec control code size is too big")
 225 #endif