Linux Audio

Check our new training course

Linux debugging, profiling, tracing and performance analysis training

Mar 24-27, 2025, special US time zones
Register
Loading...
v4.17
  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * ld script for the x86 kernel
  4 *
  5 * Historic 32-bit version written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>
  6 *
  7 * Modernisation, unification and other changes and fixes:
  8 *   Copyright (C) 2007-2009  Sam Ravnborg <sam@ravnborg.org>
  9 *
 10 *
 11 * Don't define absolute symbols until and unless you know that symbol
 12 * value is should remain constant even if kernel image is relocated
 13 * at run time. Absolute symbols are not relocated. If symbol value should
 14 * change if kernel is relocated, make the symbol section relative and
 15 * put it inside the section definition.
 16 */
 17
 18#ifdef CONFIG_X86_32
 19#define LOAD_OFFSET __PAGE_OFFSET
 20#else
 21#define LOAD_OFFSET __START_KERNEL_map
 22#endif
 23
 24#include <asm-generic/vmlinux.lds.h>
 25#include <asm/asm-offsets.h>
 26#include <asm/thread_info.h>
 27#include <asm/page_types.h>
 28#include <asm/orc_lookup.h>
 29#include <asm/cache.h>
 30#include <asm/boot.h>
 31
 32#undef i386     /* in case the preprocessor is a 32bit one */
 33
 34OUTPUT_FORMAT(CONFIG_OUTPUT_FORMAT, CONFIG_OUTPUT_FORMAT, CONFIG_OUTPUT_FORMAT)
 35
 36#ifdef CONFIG_X86_32
 37OUTPUT_ARCH(i386)
 38ENTRY(phys_startup_32)
 39jiffies = jiffies_64;
 40#else
 41OUTPUT_ARCH(i386:x86-64)
 42ENTRY(phys_startup_64)
 43jiffies_64 = jiffies;
 44#endif
 45
 46#if defined(CONFIG_X86_64)
 47/*
 48 * On 64-bit, align RODATA to 2MB so we retain large page mappings for
 49 * boundaries spanning kernel text, rodata and data sections.
 
 50 *
 51 * However, kernel identity mappings will have different RWX permissions
 52 * to the pages mapping to text and to the pages padding (which are freed) the
 53 * text section. Hence kernel identity mappings will be broken to smaller
 54 * pages. For 64-bit, kernel text and kernel identity mappings are different,
 55 * so we can enable protection checks as well as retain 2MB large page
 56 * mappings for kernel text.
 57 */
 58#define X64_ALIGN_RODATA_BEGIN	. = ALIGN(HPAGE_SIZE);
 59
 60#define X64_ALIGN_RODATA_END					\
 61		. = ALIGN(HPAGE_SIZE);				\
 62		__end_rodata_hpage_align = .;
 63
 64#define ALIGN_ENTRY_TEXT_BEGIN	. = ALIGN(PMD_SIZE);
 65#define ALIGN_ENTRY_TEXT_END	. = ALIGN(PMD_SIZE);
 66
 67#else
 68
 69#define X64_ALIGN_RODATA_BEGIN
 70#define X64_ALIGN_RODATA_END
 71
 72#define ALIGN_ENTRY_TEXT_BEGIN
 73#define ALIGN_ENTRY_TEXT_END
 74
 75#endif
 76
 77PHDRS {
 78	text PT_LOAD FLAGS(5);          /* R_E */
 79	data PT_LOAD FLAGS(6);          /* RW_ */
 80#ifdef CONFIG_X86_64
 81#ifdef CONFIG_SMP
 82	percpu PT_LOAD FLAGS(6);        /* RW_ */
 83#endif
 84	init PT_LOAD FLAGS(7);          /* RWE */
 85#endif
 86	note PT_NOTE FLAGS(0);          /* ___ */
 87}
 88
 89SECTIONS
 90{
 91#ifdef CONFIG_X86_32
 92	. = LOAD_OFFSET + LOAD_PHYSICAL_ADDR;
 93	phys_startup_32 = ABSOLUTE(startup_32 - LOAD_OFFSET);
 94#else
 95	. = __START_KERNEL;
 96	phys_startup_64 = ABSOLUTE(startup_64 - LOAD_OFFSET);
 97#endif
 98
 99	/* Text and read-only data */
100	.text :  AT(ADDR(.text) - LOAD_OFFSET) {
101		_text = .;
102		_stext = .;
103		/* bootstrapping code */
104		HEAD_TEXT
 
 
 
 
 
 
105		TEXT_TEXT
106		SCHED_TEXT
107		CPUIDLE_TEXT
108		LOCK_TEXT
109		KPROBES_TEXT
110		ALIGN_ENTRY_TEXT_BEGIN
111		ENTRY_TEXT
112		IRQENTRY_TEXT
113		ALIGN_ENTRY_TEXT_END
114		SOFTIRQENTRY_TEXT
115		*(.fixup)
116		*(.gnu.warning)
117
118#ifdef CONFIG_X86_64
119		. = ALIGN(PAGE_SIZE);
120		VMLINUX_SYMBOL(__entry_trampoline_start) = .;
121		_entry_trampoline = .;
122		*(.entry_trampoline)
123		. = ALIGN(PAGE_SIZE);
124		VMLINUX_SYMBOL(__entry_trampoline_end) = .;
125		ASSERT(. - _entry_trampoline == PAGE_SIZE, "entry trampoline is too big");
126#endif
127
128#ifdef CONFIG_RETPOLINE
129		__indirect_thunk_start = .;
130		*(.text.__x86.indirect_thunk)
131		__indirect_thunk_end = .;
132#endif
133
134		/* End of text section */
135		_etext = .;
136	} :text = 0x9090
137
138	NOTES :text :note
139
140	EXCEPTION_TABLE(16) :text = 0x9090
141
 
142	/* .text should occupy whole number of pages */
143	. = ALIGN(PAGE_SIZE);
144	X64_ALIGN_RODATA_BEGIN
 
145	RO_DATA(PAGE_SIZE)
146	X64_ALIGN_RODATA_END
147
148	/* Data */
149	.data : AT(ADDR(.data) - LOAD_OFFSET) {
150		/* Start of data section */
151		_sdata = .;
152
153		/* init_task */
154		INIT_TASK_DATA(THREAD_SIZE)
155
156#ifdef CONFIG_X86_32
157		/* 32 bit has nosave before _edata */
158		NOSAVE_DATA
159#endif
160
161		PAGE_ALIGNED_DATA(PAGE_SIZE)
162
163		CACHELINE_ALIGNED_DATA(L1_CACHE_BYTES)
164
165		DATA_DATA
166		CONSTRUCTORS
167
168		/* rarely changed data like cpu maps */
169		READ_MOSTLY_DATA(INTERNODE_CACHE_BYTES)
170
171		/* End of data section */
172		_edata = .;
173	} :data
174
175	BUG_TABLE
176
177	ORC_UNWIND_TABLE
178
179	. = ALIGN(PAGE_SIZE);
180	__vvar_page = .;
181
182	.vvar : AT(ADDR(.vvar) - LOAD_OFFSET) {
183		/* work around gold bug 13023 */
184		__vvar_beginning_hack = .;
185
186		/* Place all vvars at the offsets in asm/vvar.h. */
187#define EMIT_VVAR(name, offset) 			\
188		. = __vvar_beginning_hack + offset;	\
189		*(.vvar_ ## name)
190#define __VVAR_KERNEL_LDS
191#include <asm/vvar.h>
192#undef __VVAR_KERNEL_LDS
193#undef EMIT_VVAR
194
195		/*
196		 * Pad the rest of the page with zeros.  Otherwise the loader
197		 * can leave garbage here.
198		 */
199		. = __vvar_beginning_hack + PAGE_SIZE;
200	} :data
201
202	. = ALIGN(__vvar_page + PAGE_SIZE, PAGE_SIZE);
 
 
203
204	/* Init code and data - will be freed after init */
205	. = ALIGN(PAGE_SIZE);
206	.init.begin : AT(ADDR(.init.begin) - LOAD_OFFSET) {
207		__init_begin = .; /* paired with __init_end */
208	}
209
210#if defined(CONFIG_X86_64) && defined(CONFIG_SMP)
211	/*
212	 * percpu offsets are zero-based on SMP.  PERCPU_VADDR() changes the
213	 * output PHDR, so the next output section - .init.text - should
214	 * start another segment - init.
215	 */
216	PERCPU_VADDR(INTERNODE_CACHE_BYTES, 0, :percpu)
217	ASSERT(SIZEOF(.data..percpu) < CONFIG_PHYSICAL_START,
218	       "per-CPU data too large - increase CONFIG_PHYSICAL_START")
219#endif
220
221	INIT_TEXT_SECTION(PAGE_SIZE)
222#ifdef CONFIG_X86_64
223	:init
224#endif
225
 
 
226	/*
227	 * Section for code used exclusively before alternatives are run. All
228	 * references to such code must be patched out by alternatives, normally
229	 * by using X86_FEATURE_ALWAYS CPU feature bit.
230	 *
231	 * See static_cpu_has() for an example.
232	 */
233	.altinstr_aux : AT(ADDR(.altinstr_aux) - LOAD_OFFSET) {
234		*(.altinstr_aux)
 
 
235	}
236
237	INIT_DATA_SECTION(16)
238
239	.x86_cpu_dev.init : AT(ADDR(.x86_cpu_dev.init) - LOAD_OFFSET) {
240		__x86_cpu_dev_start = .;
241		*(.x86_cpu_dev.init)
242		__x86_cpu_dev_end = .;
243	}
244
245#ifdef CONFIG_X86_INTEL_MID
246	.x86_intel_mid_dev.init : AT(ADDR(.x86_intel_mid_dev.init) - \
247								LOAD_OFFSET) {
248		__x86_intel_mid_dev_start = .;
249		*(.x86_intel_mid_dev.init)
250		__x86_intel_mid_dev_end = .;
251	}
252#endif
253
254	/*
255	 * start address and size of operations which during runtime
256	 * can be patched with virtualization friendly instructions or
257	 * baremetal native ones. Think page table operations.
258	 * Details in paravirt_types.h
259	 */
260	. = ALIGN(8);
261	.parainstructions : AT(ADDR(.parainstructions) - LOAD_OFFSET) {
262		__parainstructions = .;
263		*(.parainstructions)
264		__parainstructions_end = .;
265	}
266
267	/*
268	 * struct alt_inst entries. From the header (alternative.h):
269	 * "Alternative instructions for different CPU types or capabilities"
270	 * Think locking instructions on spinlocks.
271	 */
272	. = ALIGN(8);
273	.altinstructions : AT(ADDR(.altinstructions) - LOAD_OFFSET) {
274		__alt_instructions = .;
275		*(.altinstructions)
276		__alt_instructions_end = .;
277	}
278
279	/*
280	 * And here are the replacement instructions. The linker sticks
281	 * them as binary blobs. The .altinstructions has enough data to
282	 * get the address and the length of them to patch the kernel safely.
283	 */
284	.altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) {
285		*(.altinstr_replacement)
286	}
287
288	/*
289	 * struct iommu_table_entry entries are injected in this section.
290	 * It is an array of IOMMUs which during run time gets sorted depending
291	 * on its dependency order. After rootfs_initcall is complete
292	 * this section can be safely removed.
293	 */
294	.iommu_table : AT(ADDR(.iommu_table) - LOAD_OFFSET) {
295		__iommu_table = .;
296		*(.iommu_table)
297		__iommu_table_end = .;
298	}
299
300	. = ALIGN(8);
301	.apicdrivers : AT(ADDR(.apicdrivers) - LOAD_OFFSET) {
302		__apicdrivers = .;
303		*(.apicdrivers);
304		__apicdrivers_end = .;
305	}
306
307	. = ALIGN(8);
308	/*
309	 * .exit.text is discard at runtime, not link time, to deal with
310	 *  references from .altinstructions and .eh_frame
311	 */
312	.exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) {
313		EXIT_TEXT
314	}
315
316	.exit.data : AT(ADDR(.exit.data) - LOAD_OFFSET) {
317		EXIT_DATA
318	}
319
320#if !defined(CONFIG_X86_64) || !defined(CONFIG_SMP)
321	PERCPU_SECTION(INTERNODE_CACHE_BYTES)
322#endif
323
324	. = ALIGN(PAGE_SIZE);
325
326	/* freed after init ends here */
327	.init.end : AT(ADDR(.init.end) - LOAD_OFFSET) {
328		__init_end = .;
329	}
330
331	/*
332	 * smp_locks might be freed after init
333	 * start/end must be page aligned
334	 */
335	. = ALIGN(PAGE_SIZE);
336	.smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) {
337		__smp_locks = .;
338		*(.smp_locks)
339		. = ALIGN(PAGE_SIZE);
340		__smp_locks_end = .;
341	}
342
343#ifdef CONFIG_X86_64
344	.data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {
345		NOSAVE_DATA
346	}
347#endif
348
349	/* BSS */
350	. = ALIGN(PAGE_SIZE);
351	.bss : AT(ADDR(.bss) - LOAD_OFFSET) {
352		__bss_start = .;
353		*(.bss..page_aligned)
354		*(.bss)
355		. = ALIGN(PAGE_SIZE);
356		__bss_stop = .;
357	}
358
359	. = ALIGN(PAGE_SIZE);
360	.brk : AT(ADDR(.brk) - LOAD_OFFSET) {
361		__brk_base = .;
362		. += 64 * 1024;		/* 64k alignment slop space */
363		*(.brk_reservation)	/* areas brk users have reserved */
364		__brk_limit = .;
365	}
366
367	. = ALIGN(PAGE_SIZE);		/* keep VO_INIT_SIZE page aligned */
368	_end = .;
369
370	STABS_DEBUG
371	DWARF_DEBUG
372
373	/* Sections to be discarded */
374	DISCARDS
375	/DISCARD/ : {
376		*(.eh_frame)
377	}
378}
379
380
381#ifdef CONFIG_X86_32
382/*
383 * The ASSERT() sink to . is intentional, for binutils 2.14 compatibility:
384 */
385. = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE),
386	   "kernel image bigger than KERNEL_IMAGE_SIZE");
387#else
388/*
389 * Per-cpu symbols which need to be offset from __per_cpu_load
390 * for the boot processor.
391 */
392#define INIT_PER_CPU(x) init_per_cpu__##x = x + __per_cpu_load
393INIT_PER_CPU(gdt_page);
394INIT_PER_CPU(irq_stack_union);
395
396/*
397 * Build-time check on the image size:
398 */
399. = ASSERT((_end - _text <= KERNEL_IMAGE_SIZE),
400	   "kernel image bigger than KERNEL_IMAGE_SIZE");
401
402#ifdef CONFIG_SMP
403. = ASSERT((irq_stack_union == 0),
404           "irq_stack_union is not at start of per-cpu area");
405#endif
406
407#endif /* CONFIG_X86_32 */
408
409#ifdef CONFIG_KEXEC_CORE
410#include <asm/kexec.h>
411
412. = ASSERT(kexec_control_code_size <= KEXEC_CONTROL_CODE_MAX_SIZE,
413           "kexec control code size is too big");
414#endif
415
v3.1
 
  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
 44#if defined(CONFIG_X86_64) && defined(CONFIG_DEBUG_RODATA)
 45/*
 46 * On 64-bit, align RODATA to 2MB so that even with CONFIG_DEBUG_RODATA
 47 * we retain large page mappings for boundaries spanning kernel text, rodata
 48 * and data sections.
 49 *
 50 * However, kernel identity mappings will have different RWX permissions
 51 * to the pages mapping to text and to the pages padding (which are freed) the
 52 * text section. Hence kernel identity mappings will be broken to smaller
 53 * pages. For 64-bit, kernel text and kernel identity mappings are different,
 54 * so we can enable protection checks that come with CONFIG_DEBUG_RODATA,
 55 * as well as retain 2MB large page mappings for kernel text.
 56 */
 57#define X64_ALIGN_DEBUG_RODATA_BEGIN	. = ALIGN(HPAGE_SIZE);
 58
 59#define X64_ALIGN_DEBUG_RODATA_END				\
 60		. = ALIGN(HPAGE_SIZE);				\
 61		__end_rodata_hpage_align = .;
 62
 
 
 
 63#else
 64
 65#define X64_ALIGN_DEBUG_RODATA_BEGIN
 66#define X64_ALIGN_DEBUG_RODATA_END
 
 
 
 67
 68#endif
 69
 70PHDRS {
 71	text PT_LOAD FLAGS(5);          /* R_E */
 72	data PT_LOAD FLAGS(6);          /* RW_ */
 73#ifdef CONFIG_X86_64
 74#ifdef CONFIG_SMP
 75	percpu PT_LOAD FLAGS(6);        /* RW_ */
 76#endif
 77	init PT_LOAD FLAGS(7);          /* RWE */
 78#endif
 79	note PT_NOTE FLAGS(0);          /* ___ */
 80}
 81
 82SECTIONS
 83{
 84#ifdef CONFIG_X86_32
 85        . = LOAD_OFFSET + LOAD_PHYSICAL_ADDR;
 86        phys_startup_32 = startup_32 - LOAD_OFFSET;
 87#else
 88        . = __START_KERNEL;
 89        phys_startup_64 = startup_64 - LOAD_OFFSET;
 90#endif
 91
 92	/* Text and read-only data */
 93	.text :  AT(ADDR(.text) - LOAD_OFFSET) {
 94		_text = .;
 
 95		/* bootstrapping code */
 96		HEAD_TEXT
 97#ifdef CONFIG_X86_32
 98		. = ALIGN(PAGE_SIZE);
 99		*(.text..page_aligned)
100#endif
101		. = ALIGN(8);
102		_stext = .;
103		TEXT_TEXT
104		SCHED_TEXT
 
105		LOCK_TEXT
106		KPROBES_TEXT
 
107		ENTRY_TEXT
108		IRQENTRY_TEXT
 
 
109		*(.fixup)
110		*(.gnu.warning)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
111		/* End of text section */
112		_etext = .;
113	} :text = 0x9090
114
115	NOTES :text :note
116
117	EXCEPTION_TABLE(16) :text = 0x9090
118
119#if defined(CONFIG_DEBUG_RODATA)
120	/* .text should occupy whole number of pages */
121	. = ALIGN(PAGE_SIZE);
122#endif
123	X64_ALIGN_DEBUG_RODATA_BEGIN
124	RO_DATA(PAGE_SIZE)
125	X64_ALIGN_DEBUG_RODATA_END
126
127	/* Data */
128	.data : AT(ADDR(.data) - LOAD_OFFSET) {
129		/* Start of data section */
130		_sdata = .;
131
132		/* init_task */
133		INIT_TASK_DATA(THREAD_SIZE)
134
135#ifdef CONFIG_X86_32
136		/* 32 bit has nosave before _edata */
137		NOSAVE_DATA
138#endif
139
140		PAGE_ALIGNED_DATA(PAGE_SIZE)
141
142		CACHELINE_ALIGNED_DATA(L1_CACHE_BYTES)
143
144		DATA_DATA
145		CONSTRUCTORS
146
147		/* rarely changed data like cpu maps */
148		READ_MOSTLY_DATA(INTERNODE_CACHE_BYTES)
149
150		/* End of data section */
151		_edata = .;
152	} :data
153
154#ifdef CONFIG_X86_64
 
 
155
156	. = ALIGN(PAGE_SIZE);
157	__vvar_page = .;
158
159	.vvar : AT(ADDR(.vvar) - LOAD_OFFSET) {
160		/* work around gold bug 13023 */
161		__vvar_beginning_hack = .;
162
163		/* Place all vvars at the offsets in asm/vvar.h. */
164#define EMIT_VVAR(name, offset) 			\
165		. = __vvar_beginning_hack + offset;	\
166		*(.vvar_ ## name)
167#define __VVAR_KERNEL_LDS
168#include <asm/vvar.h>
169#undef __VVAR_KERNEL_LDS
170#undef EMIT_VVAR
171
 
 
 
 
 
172	} :data
173
174       . = ALIGN(__vvar_page + PAGE_SIZE, PAGE_SIZE);
175
176#endif /* CONFIG_X86_64 */
177
178	/* Init code and data - will be freed after init */
179	. = ALIGN(PAGE_SIZE);
180	.init.begin : AT(ADDR(.init.begin) - LOAD_OFFSET) {
181		__init_begin = .; /* paired with __init_end */
182	}
183
184#if defined(CONFIG_X86_64) && defined(CONFIG_SMP)
185	/*
186	 * percpu offsets are zero-based on SMP.  PERCPU_VADDR() changes the
187	 * output PHDR, so the next output section - .init.text - should
188	 * start another segment - init.
189	 */
190	PERCPU_VADDR(INTERNODE_CACHE_BYTES, 0, :percpu)
 
 
191#endif
192
193	INIT_TEXT_SECTION(PAGE_SIZE)
194#ifdef CONFIG_X86_64
195	:init
196#endif
197
198	INIT_DATA_SECTION(16)
199
200	/*
201	 * Code and data for a variety of lowlevel trampolines, to be
202	 * copied into base memory (< 1 MiB) during initialization.
203	 * Since it is copied early, the main copy can be discarded
204	 * afterwards.
 
205	 */
206	 .x86_trampoline : AT(ADDR(.x86_trampoline) - LOAD_OFFSET) {
207		x86_trampoline_start = .;
208		*(.x86_trampoline)
209		x86_trampoline_end = .;
210	}
211
 
 
212	.x86_cpu_dev.init : AT(ADDR(.x86_cpu_dev.init) - LOAD_OFFSET) {
213		__x86_cpu_dev_start = .;
214		*(.x86_cpu_dev.init)
215		__x86_cpu_dev_end = .;
216	}
217
 
 
 
 
 
 
 
 
 
218	/*
219	 * start address and size of operations which during runtime
220	 * can be patched with virtualization friendly instructions or
221	 * baremetal native ones. Think page table operations.
222	 * Details in paravirt_types.h
223	 */
224	. = ALIGN(8);
225	.parainstructions : AT(ADDR(.parainstructions) - LOAD_OFFSET) {
226		__parainstructions = .;
227		*(.parainstructions)
228		__parainstructions_end = .;
229	}
230
231	/*
232	 * struct alt_inst entries. From the header (alternative.h):
233	 * "Alternative instructions for different CPU types or capabilities"
234	 * Think locking instructions on spinlocks.
235	 */
236	. = ALIGN(8);
237	.altinstructions : AT(ADDR(.altinstructions) - LOAD_OFFSET) {
238		__alt_instructions = .;
239		*(.altinstructions)
240		__alt_instructions_end = .;
241	}
242
243	/*
244	 * And here are the replacement instructions. The linker sticks
245	 * them as binary blobs. The .altinstructions has enough data to
246	 * get the address and the length of them to patch the kernel safely.
247	 */
248	.altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) {
249		*(.altinstr_replacement)
250	}
251
252	/*
253	 * struct iommu_table_entry entries are injected in this section.
254	 * It is an array of IOMMUs which during run time gets sorted depending
255	 * on its dependency order. After rootfs_initcall is complete
256	 * this section can be safely removed.
257	 */
258	.iommu_table : AT(ADDR(.iommu_table) - LOAD_OFFSET) {
259		__iommu_table = .;
260		*(.iommu_table)
261		__iommu_table_end = .;
262	}
263
264	. = ALIGN(8);
265	.apicdrivers : AT(ADDR(.apicdrivers) - LOAD_OFFSET) {
266		__apicdrivers = .;
267		*(.apicdrivers);
268		__apicdrivers_end = .;
269	}
270
271	. = ALIGN(8);
272	/*
273	 * .exit.text is discard at runtime, not link time, to deal with
274	 *  references from .altinstructions and .eh_frame
275	 */
276	.exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) {
277		EXIT_TEXT
278	}
279
280	.exit.data : AT(ADDR(.exit.data) - LOAD_OFFSET) {
281		EXIT_DATA
282	}
283
284#if !defined(CONFIG_X86_64) || !defined(CONFIG_SMP)
285	PERCPU_SECTION(INTERNODE_CACHE_BYTES)
286#endif
287
288	. = ALIGN(PAGE_SIZE);
289
290	/* freed after init ends here */
291	.init.end : AT(ADDR(.init.end) - LOAD_OFFSET) {
292		__init_end = .;
293	}
294
295	/*
296	 * smp_locks might be freed after init
297	 * start/end must be page aligned
298	 */
299	. = ALIGN(PAGE_SIZE);
300	.smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) {
301		__smp_locks = .;
302		*(.smp_locks)
303		. = ALIGN(PAGE_SIZE);
304		__smp_locks_end = .;
305	}
306
307#ifdef CONFIG_X86_64
308	.data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {
309		NOSAVE_DATA
310	}
311#endif
312
313	/* BSS */
314	. = ALIGN(PAGE_SIZE);
315	.bss : AT(ADDR(.bss) - LOAD_OFFSET) {
316		__bss_start = .;
317		*(.bss..page_aligned)
318		*(.bss)
319		. = ALIGN(PAGE_SIZE);
320		__bss_stop = .;
321	}
322
323	. = ALIGN(PAGE_SIZE);
324	.brk : AT(ADDR(.brk) - LOAD_OFFSET) {
325		__brk_base = .;
326		. += 64 * 1024;		/* 64k alignment slop space */
327		*(.brk_reservation)	/* areas brk users have reserved */
328		__brk_limit = .;
329	}
330
 
331	_end = .;
332
333        STABS_DEBUG
334        DWARF_DEBUG
335
336	/* Sections to be discarded */
337	DISCARDS
338	/DISCARD/ : { *(.eh_frame) }
 
 
339}
340
341
342#ifdef CONFIG_X86_32
343/*
344 * The ASSERT() sink to . is intentional, for binutils 2.14 compatibility:
345 */
346. = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE),
347	   "kernel image bigger than KERNEL_IMAGE_SIZE");
348#else
349/*
350 * Per-cpu symbols which need to be offset from __per_cpu_load
351 * for the boot processor.
352 */
353#define INIT_PER_CPU(x) init_per_cpu__##x = x + __per_cpu_load
354INIT_PER_CPU(gdt_page);
355INIT_PER_CPU(irq_stack_union);
356
357/*
358 * Build-time check on the image size:
359 */
360. = ASSERT((_end - _text <= KERNEL_IMAGE_SIZE),
361	   "kernel image bigger than KERNEL_IMAGE_SIZE");
362
363#ifdef CONFIG_SMP
364. = ASSERT((irq_stack_union == 0),
365           "irq_stack_union is not at start of per-cpu area");
366#endif
367
368#endif /* CONFIG_X86_32 */
369
370#ifdef CONFIG_KEXEC
371#include <asm/kexec.h>
372
373. = ASSERT(kexec_control_code_size <= KEXEC_CONTROL_CODE_MAX_SIZE,
374           "kexec control code size is too big");
375#endif
376