/*
   * ld script for the x86 kernel
   *
   * Historic 32-bit version written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>
   *

   * Modernisation, unification and other changes and fixes:
   *   Copyright (C) 2007-2009  Sam Ravnborg <sam@ravnborg.org>

   *
   *
   * Don't define absolute symbols until and unless you know that symbol
   * value is should remain constant even if kernel image is relocated
   * at run time. Absolute symbols are not relocated. If symbol value should
   * change if kernel is relocated, make the symbol section relative and
   * put it inside the section definition.
   */
  
  #ifdef CONFIG_X86_32
  #define LOAD_OFFSET __PAGE_OFFSET
  #else
  #define LOAD_OFFSET __START_KERNEL_map
  #endif
  
  #include <asm-generic/vmlinux.lds.h>
  #include <asm/asm-offsets.h>
  #include <asm/thread_info.h>
  #include <asm/page_types.h>
  #include <asm/cache.h>
  #include <asm/boot.h>
  
  #undef i386     /* in case the preprocessor is a 32bit one */
  
  OUTPUT_FORMAT(CONFIG_OUTPUT_FORMAT, CONFIG_OUTPUT_FORMAT, CONFIG_OUTPUT_FORMAT)
  
  #ifdef CONFIG_X86_32
  OUTPUT_ARCH(i386)
  ENTRY(phys_startup_32)

  jiffies = jiffies_64;

  #else
  OUTPUT_ARCH(i386:x86-64)
  ENTRY(phys_startup_64)

  jiffies_64 = jiffies;

  #endif

  #if defined(CONFIG_X86_64) && defined(CONFIG_DEBUG_RODATA)

  /*
   * On 64-bit, align RODATA to 2MB so that even with CONFIG_DEBUG_RODATA
   * we retain large page mappings for boundaries spanning kernel text, rodata
   * and data sections.
   *
   * However, kernel identity mappings will have different RWX permissions
   * to the pages mapping to text and to the pages padding (which are freed) the
   * text section. Hence kernel identity mappings will be broken to smaller
   * pages. For 64-bit, kernel text and kernel identity mappings are different,
   * so we can enable protection checks that come with CONFIG_DEBUG_RODATA,
   * as well as retain 2MB large page mappings for kernel text.
   */

  #define X64_ALIGN_DEBUG_RODATA_BEGIN	. = ALIGN(HPAGE_SIZE);
  
  #define X64_ALIGN_DEBUG_RODATA_END				\
  		. = ALIGN(HPAGE_SIZE);				\
  		__end_rodata_hpage_align = .;
  
  #else
  
  #define X64_ALIGN_DEBUG_RODATA_BEGIN
  #define X64_ALIGN_DEBUG_RODATA_END
  
  #endif

  PHDRS {
  	text PT_LOAD FLAGS(5);          /* R_E */

  	data PT_LOAD FLAGS(6);          /* RW_ */

  #ifdef CONFIG_X86_64

  #ifdef CONFIG_SMP

  	percpu PT_LOAD FLAGS(6);        /* RW_ */

  #endif

  	init PT_LOAD FLAGS(7);          /* RWE */

  #endif
  	note PT_NOTE FLAGS(0);          /* ___ */
  }

  SECTIONS
  {
  #ifdef CONFIG_X86_32
          . = LOAD_OFFSET + LOAD_PHYSICAL_ADDR;
          phys_startup_32 = startup_32 - LOAD_OFFSET;
  #else
          . = __START_KERNEL;
          phys_startup_64 = startup_64 - LOAD_OFFSET;
  #endif

  	/* Text and read-only data */

  	.text :  AT(ADDR(.text) - LOAD_OFFSET) {

  		_text = .;
  		/* bootstrapping code */
  		HEAD_TEXT

  #ifdef CONFIG_X86_32

  		. = ALIGN(PAGE_SIZE);

  		*(.text..page_aligned)

  #endif
  		. = ALIGN(8);
  		_stext = .;
  		TEXT_TEXT
  		SCHED_TEXT
  		LOCK_TEXT
  		KPROBES_TEXT

  		ENTRY_TEXT

  		IRQENTRY_TEXT
  		*(.fixup)
  		*(.gnu.warning)
  		/* End of text section */
  		_etext = .;
  	} :text = 0x9090
  
  	NOTES :text :note

  	EXCEPTION_TABLE(16) :text = 0x9090

  #if defined(CONFIG_DEBUG_RODATA)
  	/* .text should occupy whole number of pages */
  	. = ALIGN(PAGE_SIZE);
  #endif

  	X64_ALIGN_DEBUG_RODATA_BEGIN

  	RO_DATA(PAGE_SIZE)

  	X64_ALIGN_DEBUG_RODATA_END

  	/* Data */

  	.data : AT(ADDR(.data) - LOAD_OFFSET) {

  		/* Start of data section */
  		_sdata = .;

  
  		/* init_task */
  		INIT_TASK_DATA(THREAD_SIZE)

  
  #ifdef CONFIG_X86_32

  		/* 32 bit has nosave before _edata */
  		NOSAVE_DATA

  #endif

  		PAGE_ALIGNED_DATA(PAGE_SIZE)

  		CACHELINE_ALIGNED_DATA(L1_CACHE_BYTES)

  		DATA_DATA
  		CONSTRUCTORS
  
  		/* rarely changed data like cpu maps */

  		READ_MOSTLY_DATA(INTERNODE_CACHE_BYTES)

  		/* End of data section */
  		_edata = .;

  	} :data

  #ifdef CONFIG_X86_64

  	. = ALIGN(PAGE_SIZE);
  	__vvar_page = .;
  
  	.vvar : AT(ADDR(.vvar) - LOAD_OFFSET) {

  		/* work around gold bug 13023 */
  		__vvar_beginning_hack = .;

  		/* Place all vvars at the offsets in asm/vvar.h. */
  #define EMIT_VVAR(name, offset) 			\
  		. = __vvar_beginning_hack + offset;	\

  		*(.vvar_ ## name)
  #define __VVAR_KERNEL_LDS
  #include <asm/vvar.h>
  #undef __VVAR_KERNEL_LDS
  #undef EMIT_VVAR
  
  	} :data
  
         . = ALIGN(__vvar_page + PAGE_SIZE, PAGE_SIZE);

  #endif /* CONFIG_X86_64 */

  	/* Init code and data - will be freed after init */
  	. = ALIGN(PAGE_SIZE);
  	.init.begin : AT(ADDR(.init.begin) - LOAD_OFFSET) {
  		__init_begin = .; /* paired with __init_end */

  	}

  #if defined(CONFIG_X86_64) && defined(CONFIG_SMP)

  	/*

  	 * percpu offsets are zero-based on SMP.  PERCPU_VADDR() changes the
  	 * output PHDR, so the next output section - .init.text - should
  	 * start another segment - init.

  	 */

  	PERCPU_VADDR(INTERNODE_CACHE_BYTES, 0, :percpu)

  #endif

  	INIT_TEXT_SECTION(PAGE_SIZE)

  #ifdef CONFIG_X86_64
  	:init
  #endif

  	INIT_DATA_SECTION(16)

  	/*
  	 * Code and data for a variety of lowlevel trampolines, to be
  	 * copied into base memory (< 1 MiB) during initialization.
  	 * Since it is copied early, the main copy can be discarded
  	 * afterwards.
  	 */
  	 .x86_trampoline : AT(ADDR(.x86_trampoline) - LOAD_OFFSET) {
  		x86_trampoline_start = .;
  		*(.x86_trampoline)
  		x86_trampoline_end = .;
  	}

  	.x86_cpu_dev.init : AT(ADDR(.x86_cpu_dev.init) - LOAD_OFFSET) {
  		__x86_cpu_dev_start = .;
  		*(.x86_cpu_dev.init)
  		__x86_cpu_dev_end = .;
  	}

  	/*
  	 * start address and size of operations which during runtime
  	 * can be patched with virtualization friendly instructions or
  	 * baremetal native ones. Think page table operations.
  	 * Details in paravirt_types.h
  	 */

  	. = ALIGN(8);
  	.parainstructions : AT(ADDR(.parainstructions) - LOAD_OFFSET) {
  		__parainstructions = .;
  		*(.parainstructions)
  		__parainstructions_end = .;
  	}

  	/*
  	 * struct alt_inst entries. From the header (alternative.h):
  	 * "Alternative instructions for different CPU types or capabilities"
  	 * Think locking instructions on spinlocks.
  	 */

  	. = ALIGN(8);
  	.altinstructions : AT(ADDR(.altinstructions) - LOAD_OFFSET) {
  		__alt_instructions = .;
  		*(.altinstructions)
  		__alt_instructions_end = .;
  	}

  	/*
  	 * And here are the replacement instructions. The linker sticks
  	 * them as binary blobs. The .altinstructions has enough data to
  	 * get the address and the length of them to patch the kernel safely.
  	 */

  	.altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) {
  		*(.altinstr_replacement)
  	}

  	/*
  	 * struct iommu_table_entry entries are injected in this section.
  	 * It is an array of IOMMUs which during run time gets sorted depending
  	 * on its dependency order. After rootfs_initcall is complete
  	 * this section can be safely removed.
  	 */

  	.iommu_table : AT(ADDR(.iommu_table) - LOAD_OFFSET) {
  		__iommu_table = .;
  		*(.iommu_table)

  		__iommu_table_end = .;
  	}

  	. = ALIGN(8);

  	.apicdrivers : AT(ADDR(.apicdrivers) - LOAD_OFFSET) {
  		__apicdrivers = .;
  		*(.apicdrivers);
  		__apicdrivers_end = .;
  	}
  
  	. = ALIGN(8);

  	/*
  	 * .exit.text is discard at runtime, not link time, to deal with
  	 *  references from .altinstructions and .eh_frame
  	 */
  	.exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) {
  		EXIT_TEXT
  	}
  
  	.exit.data : AT(ADDR(.exit.data) - LOAD_OFFSET) {
  		EXIT_DATA
  	}

  #if !defined(CONFIG_X86_64) || !defined(CONFIG_SMP)

  	PERCPU_SECTION(INTERNODE_CACHE_BYTES)

  #endif
  
  	. = ALIGN(PAGE_SIZE);

  	/* freed after init ends here */

  	.init.end : AT(ADDR(.init.end) - LOAD_OFFSET) {
  		__init_end = .;
  	}

  	/*
  	 * smp_locks might be freed after init
  	 * start/end must be page aligned
  	 */
  	. = ALIGN(PAGE_SIZE);
  	.smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) {
  		__smp_locks = .;
  		*(.smp_locks)

  		. = ALIGN(PAGE_SIZE);

  		__smp_locks_end = .;

  	}

  #ifdef CONFIG_X86_64
  	.data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {

  		NOSAVE_DATA
  	}

  #endif

  	/* BSS */
  	. = ALIGN(PAGE_SIZE);
  	.bss : AT(ADDR(.bss) - LOAD_OFFSET) {
  		__bss_start = .;

  		*(.bss..page_aligned)

  		*(.bss)

  		. = ALIGN(PAGE_SIZE);

  		__bss_stop = .;
  	}

  	. = ALIGN(PAGE_SIZE);
  	.brk : AT(ADDR(.brk) - LOAD_OFFSET) {
  		__brk_base = .;
  		. += 64 * 1024;		/* 64k alignment slop space */
  		*(.brk_reservation)	/* areas brk users have reserved */
  		__brk_limit = .;
  	}

  	_end = .;

          STABS_DEBUG
          DWARF_DEBUG

  
  	/* Sections to be discarded */
  	DISCARDS
  	/DISCARD/ : { *(.eh_frame) }

  }

  
  #ifdef CONFIG_X86_32

  /*
   * The ASSERT() sink to . is intentional, for binutils 2.14 compatibility:
   */

  . = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE),
  	   "kernel image bigger than KERNEL_IMAGE_SIZE");

  #else
  /*
   * Per-cpu symbols which need to be offset from __per_cpu_load
   * for the boot processor.
   */

  #define INIT_PER_CPU(x) init_per_cpu__##x = x + __per_cpu_load

  INIT_PER_CPU(gdt_page);
  INIT_PER_CPU(irq_stack_union);
  
  /*
   * Build-time check on the image size:
   */

  . = ASSERT((_end - _text <= KERNEL_IMAGE_SIZE),
  	   "kernel image bigger than KERNEL_IMAGE_SIZE");

  
  #ifdef CONFIG_SMP

  . = ASSERT((irq_stack_union == 0),

             "irq_stack_union is not at start of per-cpu area");

  #endif
  
  #endif /* CONFIG_X86_32 */
  
  #ifdef CONFIG_KEXEC
  #include <asm/kexec.h>

  . = ASSERT(kexec_control_code_size <= KEXEC_CONTROL_CODE_MAX_SIZE,
             "kexec control code size is too big");

  #endif