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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/x86/kernel/vmlinux.lds.S
Initial import
Diffstat (limited to 'arch/x86/kernel/vmlinux.lds.S')
-rw-r--r--arch/x86/kernel/vmlinux.lds.S373
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diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
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+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -0,0 +1,373 @@
+/*
+ * 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
+ . = 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
+
+
+ . = 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
+
+ /*
+ * Pad the rest of the page with zeros. Otherwise the loader
+ * can leave garbage here.
+ */
+ . = __vvar_beginning_hack + PAGE_SIZE;
+ } :data
+
+ . = ALIGN(__vvar_page + PAGE_SIZE, PAGE_SIZE);
+
+ /* 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)
+ ASSERT(SIZEOF(.data..percpu) < CONFIG_PHYSICAL_START,
+ "per-CPU data too large - increase CONFIG_PHYSICAL_START")
+#endif
+
+ INIT_TEXT_SECTION(PAGE_SIZE)
+#ifdef CONFIG_X86_64
+ :init
+#endif
+
+ INIT_DATA_SECTION(16)
+
+ .x86_cpu_dev.init : AT(ADDR(.x86_cpu_dev.init) - LOAD_OFFSET) {
+ __x86_cpu_dev_start = .;
+ *(.x86_cpu_dev.init)
+ __x86_cpu_dev_end = .;
+ }
+
+#ifdef CONFIG_X86_INTEL_MID
+ .x86_intel_mid_dev.init : AT(ADDR(.x86_intel_mid_dev.init) - \
+ LOAD_OFFSET) {
+ __x86_intel_mid_dev_start = .;
+ *(.x86_intel_mid_dev.init)
+ __x86_intel_mid_dev_end = .;
+ }
+#endif
+
+ /*
+ * 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
+