linux/arch/arm/kernel/vmlinux-xip.lds.S
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2/* ld script to make ARM Linux kernel
   3 * taken from the i386 version by Russell King
   4 * Written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>
   5 */
   6
   7/* No __ro_after_init data in the .rodata section - which will always be ro */
   8#define RO_AFTER_INIT_DATA
   9
  10#include <linux/sizes.h>
  11
  12#include <asm/vmlinux.lds.h>
  13#include <asm/cache.h>
  14#include <asm/thread_info.h>
  15#include <asm/memory.h>
  16#include <asm/mpu.h>
  17#include <asm/page.h>
  18
  19OUTPUT_ARCH(arm)
  20ENTRY(stext)
  21
  22#ifndef __ARMEB__
  23jiffies = jiffies_64;
  24#else
  25jiffies = jiffies_64 + 4;
  26#endif
  27
  28SECTIONS
  29{
  30        /*
  31         * XXX: The linker does not define how output sections are
  32         * assigned to input sections when there are multiple statements
  33         * matching the same input section name.  There is no documented
  34         * order of matching.
  35         *
  36         * unwind exit sections must be discarded before the rest of the
  37         * unwind sections get included.
  38         */
  39        /DISCARD/ : {
  40                ARM_DISCARD
  41                *(.alt.smp.init)
  42                *(.pv_table)
  43#ifndef CONFIG_ARM_UNWIND
  44                *(.ARM.exidx) *(.ARM.exidx.*)
  45                *(.ARM.extab) *(.ARM.extab.*)
  46#endif
  47        }
  48
  49        . = XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR);
  50        _xiprom = .;                    /* XIP ROM area to be mapped */
  51
  52        .head.text : {
  53                _text = .;
  54                HEAD_TEXT
  55        }
  56
  57        .text : {                       /* Real text segment            */
  58                _stext = .;             /* Text and read-only data      */
  59                ARM_TEXT
  60        }
  61
  62        RO_DATA(PAGE_SIZE)
  63
  64        . = ALIGN(4);
  65        __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
  66                __start___ex_table = .;
  67                ARM_MMU_KEEP(*(__ex_table))
  68                __stop___ex_table = .;
  69        }
  70
  71#ifdef CONFIG_ARM_UNWIND
  72        ARM_UNWIND_SECTIONS
  73#endif
  74
  75        _etext = .;                     /* End of text and rodata section */
  76
  77        ARM_VECTORS
  78        INIT_TEXT_SECTION(8)
  79        .exit.text : {
  80                ARM_EXIT_KEEP(EXIT_TEXT)
  81        }
  82        .init.proc.info : {
  83                ARM_CPU_DISCARD(PROC_INFO)
  84        }
  85        .init.arch.info : {
  86                __arch_info_begin = .;
  87                *(.arch.info.init)
  88                __arch_info_end = .;
  89        }
  90        .init.tagtable : {
  91                __tagtable_begin = .;
  92                *(.taglist.init)
  93                __tagtable_end = .;
  94        }
  95        .init.rodata : {
  96                INIT_SETUP(16)
  97                INIT_CALLS
  98                CON_INITCALL
  99                INIT_RAM_FS
 100        }
 101
 102#ifdef CONFIG_ARM_MPU
 103        . = ALIGN(SZ_128K);
 104#endif
 105        _exiprom = .;                   /* End of XIP ROM area */
 106
 107/*
 108 * From this point, stuff is considered writable and will be copied to RAM
 109 */
 110        __data_loc = ALIGN(4);          /* location in file */
 111        . = PAGE_OFFSET + TEXT_OFFSET;  /* location in memory */
 112#undef LOAD_OFFSET
 113#define LOAD_OFFSET (PAGE_OFFSET + TEXT_OFFSET - __data_loc)
 114
 115        . = ALIGN(THREAD_SIZE);
 116        _sdata = .;
 117        RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
 118        .data.ro_after_init : AT(ADDR(.data.ro_after_init) - LOAD_OFFSET) {
 119                *(.data..ro_after_init)
 120        }
 121        _edata = .;
 122
 123        . = ALIGN(PAGE_SIZE);
 124        __init_begin = .;
 125        .init.data : AT(ADDR(.init.data) - LOAD_OFFSET) {
 126                INIT_DATA
 127        }
 128        .exit.data : AT(ADDR(.exit.data) - LOAD_OFFSET) {
 129                ARM_EXIT_KEEP(EXIT_DATA)
 130        }
 131#ifdef CONFIG_SMP
 132        PERCPU_SECTION(L1_CACHE_BYTES)
 133#endif
 134
 135#ifdef CONFIG_HAVE_TCM
 136        ARM_TCM
 137#endif
 138
 139        /*
 140         * End of copied data. We need a dummy section to get its LMA.
 141         * Also located before final ALIGN() as trailing padding is not stored
 142         * in the resulting binary file and useless to copy.
 143         */
 144        .data.endmark : AT(ADDR(.data.endmark) - LOAD_OFFSET) { }
 145        _edata_loc = LOADADDR(.data.endmark);
 146
 147        . = ALIGN(PAGE_SIZE);
 148        __init_end = .;
 149
 150        BSS_SECTION(0, 0, 8)
 151#ifdef CONFIG_ARM_MPU
 152        . = ALIGN(PMSAv8_MINALIGN);
 153#endif
 154        _end = .;
 155
 156        STABS_DEBUG
 157        DWARF_DEBUG
 158        ARM_DETAILS
 159
 160        ARM_ASSERTS
 161}
 162
 163/*
 164 * These must never be empty
 165 * If you have to comment these two assert statements out, your
 166 * binutils is too old (for other reasons as well)
 167 */
 168ASSERT((__proc_info_end - __proc_info_begin), "missing CPU support")
 169#ifndef CONFIG_COMPILE_TEST
 170ASSERT((__arch_info_end - __arch_info_begin), "no machine record defined")
 171#endif
 172
 173#ifdef CONFIG_XIP_DEFLATED_DATA
 174/*
 175 * The .bss is used as a stack area for __inflate_kernel_data() whose stack
 176 * frame is 9568 bytes. Make sure it has extra room left.
 177 */
 178ASSERT((_end - __bss_start) >= 12288, ".bss too small for CONFIG_XIP_DEFLATED_DATA")
 179#endif
 180
 181#if defined(CONFIG_ARM_MPU) && !defined(CONFIG_COMPILE_TEST)
 182/*
 183 * Due to PMSAv7 restriction on base address and size we have to
 184 * enforce minimal alignment restrictions. It was seen that weaker
 185 * alignment restriction on _xiprom will likely force XIP address
 186 * space spawns multiple MPU regions thus it is likely we run in
 187 * situation when we are reprogramming MPU region we run on with
 188 * something which doesn't cover reprogramming code itself, so as soon
 189 * as we update MPU settings we'd immediately try to execute straight
 190 * from background region which is XN.
 191 * It seem that alignment in 1M should suit most users.
 192 * _exiprom is aligned as 1/8 of 1M so can be covered by subregion
 193 * disable
 194 */
 195ASSERT(!(_xiprom & (SZ_1M - 1)), "XIP start address may cause MPU programming issues")
 196ASSERT(!(_exiprom & (SZ_128K - 1)), "XIP end address may cause MPU programming issues")
 197#endif
 198