xref: /openbmc/linux/arch/arm/boot/compressed/head.S (revision d2168146)
1/*
2 *  linux/arch/arm/boot/compressed/head.S
3 *
4 *  Copyright (C) 1996-2002 Russell King
5 *  Copyright (C) 2004 Hyok S. Choi (MPU support)
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11#include <linux/linkage.h>
12#include <asm/assembler.h>
13
14	.arch	armv7-a
15/*
16 * Debugging stuff
17 *
18 * Note that these macros must not contain any code which is not
19 * 100% relocatable.  Any attempt to do so will result in a crash.
20 * Please select one of the following when turning on debugging.
21 */
22#ifdef DEBUG
23
24#if defined(CONFIG_DEBUG_ICEDCC)
25
26#if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K) || defined(CONFIG_CPU_V7)
27		.macro	loadsp, rb, tmp
28		.endm
29		.macro	writeb, ch, rb
30		mcr	p14, 0, \ch, c0, c5, 0
31		.endm
32#elif defined(CONFIG_CPU_XSCALE)
33		.macro	loadsp, rb, tmp
34		.endm
35		.macro	writeb, ch, rb
36		mcr	p14, 0, \ch, c8, c0, 0
37		.endm
38#else
39		.macro	loadsp, rb, tmp
40		.endm
41		.macro	writeb, ch, rb
42		mcr	p14, 0, \ch, c1, c0, 0
43		.endm
44#endif
45
46#else
47
48#include CONFIG_DEBUG_LL_INCLUDE
49
50		.macro	writeb,	ch, rb
51		senduart \ch, \rb
52		.endm
53
54#if defined(CONFIG_ARCH_SA1100)
55		.macro	loadsp, rb, tmp
56		mov	\rb, #0x80000000	@ physical base address
57#ifdef CONFIG_DEBUG_LL_SER3
58		add	\rb, \rb, #0x00050000	@ Ser3
59#else
60		add	\rb, \rb, #0x00010000	@ Ser1
61#endif
62		.endm
63#else
64		.macro	loadsp,	rb, tmp
65		addruart \rb, \tmp
66		.endm
67#endif
68#endif
69#endif
70
71		.macro	kputc,val
72		mov	r0, \val
73		bl	putc
74		.endm
75
76		.macro	kphex,val,len
77		mov	r0, \val
78		mov	r1, #\len
79		bl	phex
80		.endm
81
82		.macro	debug_reloc_start
83#ifdef DEBUG
84		kputc	#'\n'
85		kphex	r6, 8		/* processor id */
86		kputc	#':'
87		kphex	r7, 8		/* architecture id */
88#ifdef CONFIG_CPU_CP15
89		kputc	#':'
90		mrc	p15, 0, r0, c1, c0
91		kphex	r0, 8		/* control reg */
92#endif
93		kputc	#'\n'
94		kphex	r5, 8		/* decompressed kernel start */
95		kputc	#'-'
96		kphex	r9, 8		/* decompressed kernel end  */
97		kputc	#'>'
98		kphex	r4, 8		/* kernel execution address */
99		kputc	#'\n'
100#endif
101		.endm
102
103		.macro	debug_reloc_end
104#ifdef DEBUG
105		kphex	r5, 8		/* end of kernel */
106		kputc	#'\n'
107		mov	r0, r4
108		bl	memdump		/* dump 256 bytes at start of kernel */
109#endif
110		.endm
111
112		.section ".start", #alloc, #execinstr
113/*
114 * sort out different calling conventions
115 */
116		.align
117		.arm				@ Always enter in ARM state
118start:
119		.type	start,#function
120		.rept	7
121		mov	r0, r0
122		.endr
123   ARM(		mov	r0, r0		)
124   ARM(		b	1f		)
125 THUMB(		adr	r12, BSYM(1f)	)
126 THUMB(		bx	r12		)
127
128		.word	0x016f2818		@ Magic numbers to help the loader
129		.word	start			@ absolute load/run zImage address
130		.word	_edata			@ zImage end address
131 THUMB(		.thumb			)
1321:
133 ARM_BE8(	setend	be )			@ go BE8 if compiled for BE8
134		mrs	r9, cpsr
135#ifdef CONFIG_ARM_VIRT_EXT
136		bl	__hyp_stub_install	@ get into SVC mode, reversibly
137#endif
138		mov	r7, r1			@ save architecture ID
139		mov	r8, r2			@ save atags pointer
140
141		/*
142		 * Booting from Angel - need to enter SVC mode and disable
143		 * FIQs/IRQs (numeric definitions from angel arm.h source).
144		 * We only do this if we were in user mode on entry.
145		 */
146		mrs	r2, cpsr		@ get current mode
147		tst	r2, #3			@ not user?
148		bne	not_angel
149		mov	r0, #0x17		@ angel_SWIreason_EnterSVC
150 ARM(		swi	0x123456	)	@ angel_SWI_ARM
151 THUMB(		svc	0xab		)	@ angel_SWI_THUMB
152not_angel:
153		safe_svcmode_maskall r0
154		msr	spsr_cxsf, r9		@ Save the CPU boot mode in
155						@ SPSR
156		/*
157		 * Note that some cache flushing and other stuff may
158		 * be needed here - is there an Angel SWI call for this?
159		 */
160
161		/*
162		 * some architecture specific code can be inserted
163		 * by the linker here, but it should preserve r7, r8, and r9.
164		 */
165
166		.text
167
168#ifdef CONFIG_AUTO_ZRELADDR
169		@ determine final kernel image address
170		mov	r4, pc
171		and	r4, r4, #0xf8000000
172		add	r4, r4, #TEXT_OFFSET
173#else
174		ldr	r4, =zreladdr
175#endif
176
177		/*
178		 * Set up a page table only if it won't overwrite ourself.
179		 * That means r4 < pc && r4 - 16k page directory > &_end.
180		 * Given that r4 > &_end is most unfrequent, we add a rough
181		 * additional 1MB of room for a possible appended DTB.
182		 */
183		mov	r0, pc
184		cmp	r0, r4
185		ldrcc	r0, LC0+32
186		addcc	r0, r0, pc
187		cmpcc	r4, r0
188		orrcc	r4, r4, #1		@ remember we skipped cache_on
189		blcs	cache_on
190
191restart:	adr	r0, LC0
192		ldmia	r0, {r1, r2, r3, r6, r10, r11, r12}
193		ldr	sp, [r0, #28]
194
195		/*
196		 * We might be running at a different address.  We need
197		 * to fix up various pointers.
198		 */
199		sub	r0, r0, r1		@ calculate the delta offset
200		add	r6, r6, r0		@ _edata
201		add	r10, r10, r0		@ inflated kernel size location
202
203		/*
204		 * The kernel build system appends the size of the
205		 * decompressed kernel at the end of the compressed data
206		 * in little-endian form.
207		 */
208		ldrb	r9, [r10, #0]
209		ldrb	lr, [r10, #1]
210		orr	r9, r9, lr, lsl #8
211		ldrb	lr, [r10, #2]
212		ldrb	r10, [r10, #3]
213		orr	r9, r9, lr, lsl #16
214		orr	r9, r9, r10, lsl #24
215
216#ifndef CONFIG_ZBOOT_ROM
217		/* malloc space is above the relocated stack (64k max) */
218		add	sp, sp, r0
219		add	r10, sp, #0x10000
220#else
221		/*
222		 * With ZBOOT_ROM the bss/stack is non relocatable,
223		 * but someone could still run this code from RAM,
224		 * in which case our reference is _edata.
225		 */
226		mov	r10, r6
227#endif
228
229		mov	r5, #0			@ init dtb size to 0
230#ifdef CONFIG_ARM_APPENDED_DTB
231/*
232 *   r0  = delta
233 *   r2  = BSS start
234 *   r3  = BSS end
235 *   r4  = final kernel address (possibly with LSB set)
236 *   r5  = appended dtb size (still unknown)
237 *   r6  = _edata
238 *   r7  = architecture ID
239 *   r8  = atags/device tree pointer
240 *   r9  = size of decompressed image
241 *   r10 = end of this image, including  bss/stack/malloc space if non XIP
242 *   r11 = GOT start
243 *   r12 = GOT end
244 *   sp  = stack pointer
245 *
246 * if there are device trees (dtb) appended to zImage, advance r10 so that the
247 * dtb data will get relocated along with the kernel if necessary.
248 */
249
250		ldr	lr, [r6, #0]
251#ifndef __ARMEB__
252		ldr	r1, =0xedfe0dd0		@ sig is 0xd00dfeed big endian
253#else
254		ldr	r1, =0xd00dfeed
255#endif
256		cmp	lr, r1
257		bne	dtb_check_done		@ not found
258
259#ifdef CONFIG_ARM_ATAG_DTB_COMPAT
260		/*
261		 * OK... Let's do some funky business here.
262		 * If we do have a DTB appended to zImage, and we do have
263		 * an ATAG list around, we want the later to be translated
264		 * and folded into the former here.  To be on the safe side,
265		 * let's temporarily move  the stack away into the malloc
266		 * area.  No GOT fixup has occurred yet, but none of the
267		 * code we're about to call uses any global variable.
268		*/
269		add	sp, sp, #0x10000
270		stmfd	sp!, {r0-r3, ip, lr}
271		mov	r0, r8
272		mov	r1, r6
273		sub	r2, sp, r6
274		bl	atags_to_fdt
275
276		/*
277		 * If returned value is 1, there is no ATAG at the location
278		 * pointed by r8.  Try the typical 0x100 offset from start
279		 * of RAM and hope for the best.
280		 */
281		cmp	r0, #1
282		sub	r0, r4, #TEXT_OFFSET
283		bic	r0, r0, #1
284		add	r0, r0, #0x100
285		mov	r1, r6
286		sub	r2, sp, r6
287		bleq	atags_to_fdt
288
289		ldmfd	sp!, {r0-r3, ip, lr}
290		sub	sp, sp, #0x10000
291#endif
292
293		mov	r8, r6			@ use the appended device tree
294
295		/*
296		 * Make sure that the DTB doesn't end up in the final
297		 * kernel's .bss area. To do so, we adjust the decompressed
298		 * kernel size to compensate if that .bss size is larger
299		 * than the relocated code.
300		 */
301		ldr	r5, =_kernel_bss_size
302		adr	r1, wont_overwrite
303		sub	r1, r6, r1
304		subs	r1, r5, r1
305		addhi	r9, r9, r1
306
307		/* Get the dtb's size */
308		ldr	r5, [r6, #4]
309#ifndef __ARMEB__
310		/* convert r5 (dtb size) to little endian */
311		eor	r1, r5, r5, ror #16
312		bic	r1, r1, #0x00ff0000
313		mov	r5, r5, ror #8
314		eor	r5, r5, r1, lsr #8
315#endif
316
317		/* preserve 64-bit alignment */
318		add	r5, r5, #7
319		bic	r5, r5, #7
320
321		/* relocate some pointers past the appended dtb */
322		add	r6, r6, r5
323		add	r10, r10, r5
324		add	sp, sp, r5
325dtb_check_done:
326#endif
327
328/*
329 * Check to see if we will overwrite ourselves.
330 *   r4  = final kernel address (possibly with LSB set)
331 *   r9  = size of decompressed image
332 *   r10 = end of this image, including  bss/stack/malloc space if non XIP
333 * We basically want:
334 *   r4 - 16k page directory >= r10 -> OK
335 *   r4 + image length <= address of wont_overwrite -> OK
336 * Note: the possible LSB in r4 is harmless here.
337 */
338		add	r10, r10, #16384
339		cmp	r4, r10
340		bhs	wont_overwrite
341		add	r10, r4, r9
342		adr	r9, wont_overwrite
343		cmp	r10, r9
344		bls	wont_overwrite
345
346/*
347 * Relocate ourselves past the end of the decompressed kernel.
348 *   r6  = _edata
349 *   r10 = end of the decompressed kernel
350 * Because we always copy ahead, we need to do it from the end and go
351 * backward in case the source and destination overlap.
352 */
353		/*
354		 * Bump to the next 256-byte boundary with the size of
355		 * the relocation code added. This avoids overwriting
356		 * ourself when the offset is small.
357		 */
358		add	r10, r10, #((reloc_code_end - restart + 256) & ~255)
359		bic	r10, r10, #255
360
361		/* Get start of code we want to copy and align it down. */
362		adr	r5, restart
363		bic	r5, r5, #31
364
365/* Relocate the hyp vector base if necessary */
366#ifdef CONFIG_ARM_VIRT_EXT
367		mrs	r0, spsr
368		and	r0, r0, #MODE_MASK
369		cmp	r0, #HYP_MODE
370		bne	1f
371
372		bl	__hyp_get_vectors
373		sub	r0, r0, r5
374		add	r0, r0, r10
375		bl	__hyp_set_vectors
3761:
377#endif
378
379		sub	r9, r6, r5		@ size to copy
380		add	r9, r9, #31		@ rounded up to a multiple
381		bic	r9, r9, #31		@ ... of 32 bytes
382		add	r6, r9, r5
383		add	r9, r9, r10
384
3851:		ldmdb	r6!, {r0 - r3, r10 - r12, lr}
386		cmp	r6, r5
387		stmdb	r9!, {r0 - r3, r10 - r12, lr}
388		bhi	1b
389
390		/* Preserve offset to relocated code. */
391		sub	r6, r9, r6
392
393#ifndef CONFIG_ZBOOT_ROM
394		/* cache_clean_flush may use the stack, so relocate it */
395		add	sp, sp, r6
396#endif
397
398		tst	r4, #1
399		bleq	cache_clean_flush
400
401		adr	r0, BSYM(restart)
402		add	r0, r0, r6
403		mov	pc, r0
404
405wont_overwrite:
406/*
407 * If delta is zero, we are running at the address we were linked at.
408 *   r0  = delta
409 *   r2  = BSS start
410 *   r3  = BSS end
411 *   r4  = kernel execution address (possibly with LSB set)
412 *   r5  = appended dtb size (0 if not present)
413 *   r7  = architecture ID
414 *   r8  = atags pointer
415 *   r11 = GOT start
416 *   r12 = GOT end
417 *   sp  = stack pointer
418 */
419		orrs	r1, r0, r5
420		beq	not_relocated
421
422		add	r11, r11, r0
423		add	r12, r12, r0
424
425#ifndef CONFIG_ZBOOT_ROM
426		/*
427		 * If we're running fully PIC === CONFIG_ZBOOT_ROM = n,
428		 * we need to fix up pointers into the BSS region.
429		 * Note that the stack pointer has already been fixed up.
430		 */
431		add	r2, r2, r0
432		add	r3, r3, r0
433
434		/*
435		 * Relocate all entries in the GOT table.
436		 * Bump bss entries to _edata + dtb size
437		 */
4381:		ldr	r1, [r11, #0]		@ relocate entries in the GOT
439		add	r1, r1, r0		@ This fixes up C references
440		cmp	r1, r2			@ if entry >= bss_start &&
441		cmphs	r3, r1			@       bss_end > entry
442		addhi	r1, r1, r5		@    entry += dtb size
443		str	r1, [r11], #4		@ next entry
444		cmp	r11, r12
445		blo	1b
446
447		/* bump our bss pointers too */
448		add	r2, r2, r5
449		add	r3, r3, r5
450
451#else
452
453		/*
454		 * Relocate entries in the GOT table.  We only relocate
455		 * the entries that are outside the (relocated) BSS region.
456		 */
4571:		ldr	r1, [r11, #0]		@ relocate entries in the GOT
458		cmp	r1, r2			@ entry < bss_start ||
459		cmphs	r3, r1			@ _end < entry
460		addlo	r1, r1, r0		@ table.  This fixes up the
461		str	r1, [r11], #4		@ C references.
462		cmp	r11, r12
463		blo	1b
464#endif
465
466not_relocated:	mov	r0, #0
4671:		str	r0, [r2], #4		@ clear bss
468		str	r0, [r2], #4
469		str	r0, [r2], #4
470		str	r0, [r2], #4
471		cmp	r2, r3
472		blo	1b
473
474		/*
475		 * Did we skip the cache setup earlier?
476		 * That is indicated by the LSB in r4.
477		 * Do it now if so.
478		 */
479		tst	r4, #1
480		bic	r4, r4, #1
481		blne	cache_on
482
483/*
484 * The C runtime environment should now be setup sufficiently.
485 * Set up some pointers, and start decompressing.
486 *   r4  = kernel execution address
487 *   r7  = architecture ID
488 *   r8  = atags pointer
489 */
490		mov	r0, r4
491		mov	r1, sp			@ malloc space above stack
492		add	r2, sp, #0x10000	@ 64k max
493		mov	r3, r7
494		bl	decompress_kernel
495		bl	cache_clean_flush
496		bl	cache_off
497		mov	r1, r7			@ restore architecture number
498		mov	r2, r8			@ restore atags pointer
499
500#ifdef CONFIG_ARM_VIRT_EXT
501		mrs	r0, spsr		@ Get saved CPU boot mode
502		and	r0, r0, #MODE_MASK
503		cmp	r0, #HYP_MODE		@ if not booted in HYP mode...
504		bne	__enter_kernel		@ boot kernel directly
505
506		adr	r12, .L__hyp_reentry_vectors_offset
507		ldr	r0, [r12]
508		add	r0, r0, r12
509
510		bl	__hyp_set_vectors
511		__HVC(0)			@ otherwise bounce to hyp mode
512
513		b	.			@ should never be reached
514
515		.align	2
516.L__hyp_reentry_vectors_offset:	.long	__hyp_reentry_vectors - .
517#else
518		b	__enter_kernel
519#endif
520
521		.align	2
522		.type	LC0, #object
523LC0:		.word	LC0			@ r1
524		.word	__bss_start		@ r2
525		.word	_end			@ r3
526		.word	_edata			@ r6
527		.word	input_data_end - 4	@ r10 (inflated size location)
528		.word	_got_start		@ r11
529		.word	_got_end		@ ip
530		.word	.L_user_stack_end	@ sp
531		.word	_end - restart + 16384 + 1024*1024
532		.size	LC0, . - LC0
533
534#ifdef CONFIG_ARCH_RPC
535		.globl	params
536params:		ldr	r0, =0x10000100		@ params_phys for RPC
537		mov	pc, lr
538		.ltorg
539		.align
540#endif
541
542/*
543 * Turn on the cache.  We need to setup some page tables so that we
544 * can have both the I and D caches on.
545 *
546 * We place the page tables 16k down from the kernel execution address,
547 * and we hope that nothing else is using it.  If we're using it, we
548 * will go pop!
549 *
550 * On entry,
551 *  r4 = kernel execution address
552 *  r7 = architecture number
553 *  r8 = atags pointer
554 * On exit,
555 *  r0, r1, r2, r3, r9, r10, r12 corrupted
556 * This routine must preserve:
557 *  r4, r7, r8
558 */
559		.align	5
560cache_on:	mov	r3, #8			@ cache_on function
561		b	call_cache_fn
562
563/*
564 * Initialize the highest priority protection region, PR7
565 * to cover all 32bit address and cacheable and bufferable.
566 */
567__armv4_mpu_cache_on:
568		mov	r0, #0x3f		@ 4G, the whole
569		mcr	p15, 0, r0, c6, c7, 0	@ PR7 Area Setting
570		mcr 	p15, 0, r0, c6, c7, 1
571
572		mov	r0, #0x80		@ PR7
573		mcr	p15, 0, r0, c2, c0, 0	@ D-cache on
574		mcr	p15, 0, r0, c2, c0, 1	@ I-cache on
575		mcr	p15, 0, r0, c3, c0, 0	@ write-buffer on
576
577		mov	r0, #0xc000
578		mcr	p15, 0, r0, c5, c0, 1	@ I-access permission
579		mcr	p15, 0, r0, c5, c0, 0	@ D-access permission
580
581		mov	r0, #0
582		mcr	p15, 0, r0, c7, c10, 4	@ drain write buffer
583		mcr	p15, 0, r0, c7, c5, 0	@ flush(inval) I-Cache
584		mcr	p15, 0, r0, c7, c6, 0	@ flush(inval) D-Cache
585		mrc	p15, 0, r0, c1, c0, 0	@ read control reg
586						@ ...I .... ..D. WC.M
587		orr	r0, r0, #0x002d		@ .... .... ..1. 11.1
588		orr	r0, r0, #0x1000		@ ...1 .... .... ....
589
590		mcr	p15, 0, r0, c1, c0, 0	@ write control reg
591
592		mov	r0, #0
593		mcr	p15, 0, r0, c7, c5, 0	@ flush(inval) I-Cache
594		mcr	p15, 0, r0, c7, c6, 0	@ flush(inval) D-Cache
595		mov	pc, lr
596
597__armv3_mpu_cache_on:
598		mov	r0, #0x3f		@ 4G, the whole
599		mcr	p15, 0, r0, c6, c7, 0	@ PR7 Area Setting
600
601		mov	r0, #0x80		@ PR7
602		mcr	p15, 0, r0, c2, c0, 0	@ cache on
603		mcr	p15, 0, r0, c3, c0, 0	@ write-buffer on
604
605		mov	r0, #0xc000
606		mcr	p15, 0, r0, c5, c0, 0	@ access permission
607
608		mov	r0, #0
609		mcr	p15, 0, r0, c7, c0, 0	@ invalidate whole cache v3
610		/*
611		 * ?? ARMv3 MMU does not allow reading the control register,
612		 * does this really work on ARMv3 MPU?
613		 */
614		mrc	p15, 0, r0, c1, c0, 0	@ read control reg
615						@ .... .... .... WC.M
616		orr	r0, r0, #0x000d		@ .... .... .... 11.1
617		/* ?? this overwrites the value constructed above? */
618		mov	r0, #0
619		mcr	p15, 0, r0, c1, c0, 0	@ write control reg
620
621		/* ?? invalidate for the second time? */
622		mcr	p15, 0, r0, c7, c0, 0	@ invalidate whole cache v3
623		mov	pc, lr
624
625#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
626#define CB_BITS 0x08
627#else
628#define CB_BITS 0x0c
629#endif
630
631__setup_mmu:	sub	r3, r4, #16384		@ Page directory size
632		bic	r3, r3, #0xff		@ Align the pointer
633		bic	r3, r3, #0x3f00
634/*
635 * Initialise the page tables, turning on the cacheable and bufferable
636 * bits for the RAM area only.
637 */
638		mov	r0, r3
639		mov	r9, r0, lsr #18
640		mov	r9, r9, lsl #18		@ start of RAM
641		add	r10, r9, #0x10000000	@ a reasonable RAM size
642		mov	r1, #0x12		@ XN|U + section mapping
643		orr	r1, r1, #3 << 10	@ AP=11
644		add	r2, r3, #16384
6451:		cmp	r1, r9			@ if virt > start of RAM
646		cmphs	r10, r1			@   && end of RAM > virt
647		bic	r1, r1, #0x1c		@ clear XN|U + C + B
648		orrlo	r1, r1, #0x10		@ Set XN|U for non-RAM
649		orrhs	r1, r1, r6		@ set RAM section settings
650		str	r1, [r0], #4		@ 1:1 mapping
651		add	r1, r1, #1048576
652		teq	r0, r2
653		bne	1b
654/*
655 * If ever we are running from Flash, then we surely want the cache
656 * to be enabled also for our execution instance...  We map 2MB of it
657 * so there is no map overlap problem for up to 1 MB compressed kernel.
658 * If the execution is in RAM then we would only be duplicating the above.
659 */
660		orr	r1, r6, #0x04		@ ensure B is set for this
661		orr	r1, r1, #3 << 10
662		mov	r2, pc
663		mov	r2, r2, lsr #20
664		orr	r1, r1, r2, lsl #20
665		add	r0, r3, r2, lsl #2
666		str	r1, [r0], #4
667		add	r1, r1, #1048576
668		str	r1, [r0]
669		mov	pc, lr
670ENDPROC(__setup_mmu)
671
672@ Enable unaligned access on v6, to allow better code generation
673@ for the decompressor C code:
674__armv6_mmu_cache_on:
675		mrc	p15, 0, r0, c1, c0, 0	@ read SCTLR
676		bic	r0, r0, #2		@ A (no unaligned access fault)
677		orr	r0, r0, #1 << 22	@ U (v6 unaligned access model)
678		mcr	p15, 0, r0, c1, c0, 0	@ write SCTLR
679		b	__armv4_mmu_cache_on
680
681__arm926ejs_mmu_cache_on:
682#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
683		mov	r0, #4			@ put dcache in WT mode
684		mcr	p15, 7, r0, c15, c0, 0
685#endif
686
687__armv4_mmu_cache_on:
688		mov	r12, lr
689#ifdef CONFIG_MMU
690		mov	r6, #CB_BITS | 0x12	@ U
691		bl	__setup_mmu
692		mov	r0, #0
693		mcr	p15, 0, r0, c7, c10, 4	@ drain write buffer
694		mcr	p15, 0, r0, c8, c7, 0	@ flush I,D TLBs
695		mrc	p15, 0, r0, c1, c0, 0	@ read control reg
696		orr	r0, r0, #0x5000		@ I-cache enable, RR cache replacement
697		orr	r0, r0, #0x0030
698 ARM_BE8(	orr	r0, r0, #1 << 25 )	@ big-endian page tables
699		bl	__common_mmu_cache_on
700		mov	r0, #0
701		mcr	p15, 0, r0, c8, c7, 0	@ flush I,D TLBs
702#endif
703		mov	pc, r12
704
705__armv7_mmu_cache_on:
706		mov	r12, lr
707#ifdef CONFIG_MMU
708		mrc	p15, 0, r11, c0, c1, 4	@ read ID_MMFR0
709		tst	r11, #0xf		@ VMSA
710		movne	r6, #CB_BITS | 0x02	@ !XN
711		blne	__setup_mmu
712		mov	r0, #0
713		mcr	p15, 0, r0, c7, c10, 4	@ drain write buffer
714		tst	r11, #0xf		@ VMSA
715		mcrne	p15, 0, r0, c8, c7, 0	@ flush I,D TLBs
716#endif
717		mrc	p15, 0, r0, c1, c0, 0	@ read control reg
718		bic	r0, r0, #1 << 28	@ clear SCTLR.TRE
719		orr	r0, r0, #0x5000		@ I-cache enable, RR cache replacement
720		orr	r0, r0, #0x003c		@ write buffer
721		bic	r0, r0, #2		@ A (no unaligned access fault)
722		orr	r0, r0, #1 << 22	@ U (v6 unaligned access model)
723						@ (needed for ARM1176)
724#ifdef CONFIG_MMU
725 ARM_BE8(	orr	r0, r0, #1 << 25 )	@ big-endian page tables
726		mrcne   p15, 0, r6, c2, c0, 2   @ read ttb control reg
727		orrne	r0, r0, #1		@ MMU enabled
728		movne	r1, #0xfffffffd		@ domain 0 = client
729		bic     r6, r6, #1 << 31        @ 32-bit translation system
730		bic     r6, r6, #3 << 0         @ use only ttbr0
731		mcrne	p15, 0, r3, c2, c0, 0	@ load page table pointer
732		mcrne	p15, 0, r1, c3, c0, 0	@ load domain access control
733		mcrne   p15, 0, r6, c2, c0, 2   @ load ttb control
734#endif
735		mcr	p15, 0, r0, c7, c5, 4	@ ISB
736		mcr	p15, 0, r0, c1, c0, 0	@ load control register
737		mrc	p15, 0, r0, c1, c0, 0	@ and read it back
738		mov	r0, #0
739		mcr	p15, 0, r0, c7, c5, 4	@ ISB
740		mov	pc, r12
741
742__fa526_cache_on:
743		mov	r12, lr
744		mov	r6, #CB_BITS | 0x12	@ U
745		bl	__setup_mmu
746		mov	r0, #0
747		mcr	p15, 0, r0, c7, c7, 0	@ Invalidate whole cache
748		mcr	p15, 0, r0, c7, c10, 4	@ drain write buffer
749		mcr	p15, 0, r0, c8, c7, 0	@ flush UTLB
750		mrc	p15, 0, r0, c1, c0, 0	@ read control reg
751		orr	r0, r0, #0x1000		@ I-cache enable
752		bl	__common_mmu_cache_on
753		mov	r0, #0
754		mcr	p15, 0, r0, c8, c7, 0	@ flush UTLB
755		mov	pc, r12
756
757__common_mmu_cache_on:
758#ifndef CONFIG_THUMB2_KERNEL
759#ifndef DEBUG
760		orr	r0, r0, #0x000d		@ Write buffer, mmu
761#endif
762		mov	r1, #-1
763		mcr	p15, 0, r3, c2, c0, 0	@ load page table pointer
764		mcr	p15, 0, r1, c3, c0, 0	@ load domain access control
765		b	1f
766		.align	5			@ cache line aligned
7671:		mcr	p15, 0, r0, c1, c0, 0	@ load control register
768		mrc	p15, 0, r0, c1, c0, 0	@ and read it back to
769		sub	pc, lr, r0, lsr #32	@ properly flush pipeline
770#endif
771
772#define PROC_ENTRY_SIZE (4*5)
773
774/*
775 * Here follow the relocatable cache support functions for the
776 * various processors.  This is a generic hook for locating an
777 * entry and jumping to an instruction at the specified offset
778 * from the start of the block.  Please note this is all position
779 * independent code.
780 *
781 *  r1  = corrupted
782 *  r2  = corrupted
783 *  r3  = block offset
784 *  r9  = corrupted
785 *  r12 = corrupted
786 */
787
788call_cache_fn:	adr	r12, proc_types
789#ifdef CONFIG_CPU_CP15
790		mrc	p15, 0, r9, c0, c0	@ get processor ID
791#else
792		ldr	r9, =CONFIG_PROCESSOR_ID
793#endif
7941:		ldr	r1, [r12, #0]		@ get value
795		ldr	r2, [r12, #4]		@ get mask
796		eor	r1, r1, r9		@ (real ^ match)
797		tst	r1, r2			@       & mask
798 ARM(		addeq	pc, r12, r3		) @ call cache function
799 THUMB(		addeq	r12, r3			)
800 THUMB(		moveq	pc, r12			) @ call cache function
801		add	r12, r12, #PROC_ENTRY_SIZE
802		b	1b
803
804/*
805 * Table for cache operations.  This is basically:
806 *   - CPU ID match
807 *   - CPU ID mask
808 *   - 'cache on' method instruction
809 *   - 'cache off' method instruction
810 *   - 'cache flush' method instruction
811 *
812 * We match an entry using: ((real_id ^ match) & mask) == 0
813 *
814 * Writethrough caches generally only need 'on' and 'off'
815 * methods.  Writeback caches _must_ have the flush method
816 * defined.
817 */
818		.align	2
819		.type	proc_types,#object
820proc_types:
821		.word	0x41000000		@ old ARM ID
822		.word	0xff00f000
823		mov	pc, lr
824 THUMB(		nop				)
825		mov	pc, lr
826 THUMB(		nop				)
827		mov	pc, lr
828 THUMB(		nop				)
829
830		.word	0x41007000		@ ARM7/710
831		.word	0xfff8fe00
832		mov	pc, lr
833 THUMB(		nop				)
834		mov	pc, lr
835 THUMB(		nop				)
836		mov	pc, lr
837 THUMB(		nop				)
838
839		.word	0x41807200		@ ARM720T (writethrough)
840		.word	0xffffff00
841		W(b)	__armv4_mmu_cache_on
842		W(b)	__armv4_mmu_cache_off
843		mov	pc, lr
844 THUMB(		nop				)
845
846		.word	0x41007400		@ ARM74x
847		.word	0xff00ff00
848		W(b)	__armv3_mpu_cache_on
849		W(b)	__armv3_mpu_cache_off
850		W(b)	__armv3_mpu_cache_flush
851
852		.word	0x41009400		@ ARM94x
853		.word	0xff00ff00
854		W(b)	__armv4_mpu_cache_on
855		W(b)	__armv4_mpu_cache_off
856		W(b)	__armv4_mpu_cache_flush
857
858		.word	0x41069260		@ ARM926EJ-S (v5TEJ)
859		.word	0xff0ffff0
860		W(b)	__arm926ejs_mmu_cache_on
861		W(b)	__armv4_mmu_cache_off
862		W(b)	__armv5tej_mmu_cache_flush
863
864		.word	0x00007000		@ ARM7 IDs
865		.word	0x0000f000
866		mov	pc, lr
867 THUMB(		nop				)
868		mov	pc, lr
869 THUMB(		nop				)
870		mov	pc, lr
871 THUMB(		nop				)
872
873		@ Everything from here on will be the new ID system.
874
875		.word	0x4401a100		@ sa110 / sa1100
876		.word	0xffffffe0
877		W(b)	__armv4_mmu_cache_on
878		W(b)	__armv4_mmu_cache_off
879		W(b)	__armv4_mmu_cache_flush
880
881		.word	0x6901b110		@ sa1110
882		.word	0xfffffff0
883		W(b)	__armv4_mmu_cache_on
884		W(b)	__armv4_mmu_cache_off
885		W(b)	__armv4_mmu_cache_flush
886
887		.word	0x56056900
888		.word	0xffffff00		@ PXA9xx
889		W(b)	__armv4_mmu_cache_on
890		W(b)	__armv4_mmu_cache_off
891		W(b)	__armv4_mmu_cache_flush
892
893		.word	0x56158000		@ PXA168
894		.word	0xfffff000
895		W(b)	__armv4_mmu_cache_on
896		W(b)	__armv4_mmu_cache_off
897		W(b)	__armv5tej_mmu_cache_flush
898
899		.word	0x56050000		@ Feroceon
900		.word	0xff0f0000
901		W(b)	__armv4_mmu_cache_on
902		W(b)	__armv4_mmu_cache_off
903		W(b)	__armv5tej_mmu_cache_flush
904
905#ifdef CONFIG_CPU_FEROCEON_OLD_ID
906		/* this conflicts with the standard ARMv5TE entry */
907		.long	0x41009260		@ Old Feroceon
908		.long	0xff00fff0
909		b	__armv4_mmu_cache_on
910		b	__armv4_mmu_cache_off
911		b	__armv5tej_mmu_cache_flush
912#endif
913
914		.word	0x66015261		@ FA526
915		.word	0xff01fff1
916		W(b)	__fa526_cache_on
917		W(b)	__armv4_mmu_cache_off
918		W(b)	__fa526_cache_flush
919
920		@ These match on the architecture ID
921
922		.word	0x00020000		@ ARMv4T
923		.word	0x000f0000
924		W(b)	__armv4_mmu_cache_on
925		W(b)	__armv4_mmu_cache_off
926		W(b)	__armv4_mmu_cache_flush
927
928		.word	0x00050000		@ ARMv5TE
929		.word	0x000f0000
930		W(b)	__armv4_mmu_cache_on
931		W(b)	__armv4_mmu_cache_off
932		W(b)	__armv4_mmu_cache_flush
933
934		.word	0x00060000		@ ARMv5TEJ
935		.word	0x000f0000
936		W(b)	__armv4_mmu_cache_on
937		W(b)	__armv4_mmu_cache_off
938		W(b)	__armv5tej_mmu_cache_flush
939
940		.word	0x0007b000		@ ARMv6
941		.word	0x000ff000
942		W(b)	__armv6_mmu_cache_on
943		W(b)	__armv4_mmu_cache_off
944		W(b)	__armv6_mmu_cache_flush
945
946		.word	0x000f0000		@ new CPU Id
947		.word	0x000f0000
948		W(b)	__armv7_mmu_cache_on
949		W(b)	__armv7_mmu_cache_off
950		W(b)	__armv7_mmu_cache_flush
951
952		.word	0			@ unrecognised type
953		.word	0
954		mov	pc, lr
955 THUMB(		nop				)
956		mov	pc, lr
957 THUMB(		nop				)
958		mov	pc, lr
959 THUMB(		nop				)
960
961		.size	proc_types, . - proc_types
962
963		/*
964		 * If you get a "non-constant expression in ".if" statement"
965		 * error from the assembler on this line, check that you have
966		 * not accidentally written a "b" instruction where you should
967		 * have written W(b).
968		 */
969		.if (. - proc_types) % PROC_ENTRY_SIZE != 0
970		.error "The size of one or more proc_types entries is wrong."
971		.endif
972
973/*
974 * Turn off the Cache and MMU.  ARMv3 does not support
975 * reading the control register, but ARMv4 does.
976 *
977 * On exit,
978 *  r0, r1, r2, r3, r9, r12 corrupted
979 * This routine must preserve:
980 *  r4, r7, r8
981 */
982		.align	5
983cache_off:	mov	r3, #12			@ cache_off function
984		b	call_cache_fn
985
986__armv4_mpu_cache_off:
987		mrc	p15, 0, r0, c1, c0
988		bic	r0, r0, #0x000d
989		mcr	p15, 0, r0, c1, c0	@ turn MPU and cache off
990		mov	r0, #0
991		mcr	p15, 0, r0, c7, c10, 4	@ drain write buffer
992		mcr	p15, 0, r0, c7, c6, 0	@ flush D-Cache
993		mcr	p15, 0, r0, c7, c5, 0	@ flush I-Cache
994		mov	pc, lr
995
996__armv3_mpu_cache_off:
997		mrc	p15, 0, r0, c1, c0
998		bic	r0, r0, #0x000d
999		mcr	p15, 0, r0, c1, c0, 0	@ turn MPU and cache off
1000		mov	r0, #0
1001		mcr	p15, 0, r0, c7, c0, 0	@ invalidate whole cache v3
1002		mov	pc, lr
1003
1004__armv4_mmu_cache_off:
1005#ifdef CONFIG_MMU
1006		mrc	p15, 0, r0, c1, c0
1007		bic	r0, r0, #0x000d
1008		mcr	p15, 0, r0, c1, c0	@ turn MMU and cache off
1009		mov	r0, #0
1010		mcr	p15, 0, r0, c7, c7	@ invalidate whole cache v4
1011		mcr	p15, 0, r0, c8, c7	@ invalidate whole TLB v4
1012#endif
1013		mov	pc, lr
1014
1015__armv7_mmu_cache_off:
1016		mrc	p15, 0, r0, c1, c0
1017#ifdef CONFIG_MMU
1018		bic	r0, r0, #0x000d
1019#else
1020		bic	r0, r0, #0x000c
1021#endif
1022		mcr	p15, 0, r0, c1, c0	@ turn MMU and cache off
1023		mov	r12, lr
1024		bl	__armv7_mmu_cache_flush
1025		mov	r0, #0
1026#ifdef CONFIG_MMU
1027		mcr	p15, 0, r0, c8, c7, 0	@ invalidate whole TLB
1028#endif
1029		mcr	p15, 0, r0, c7, c5, 6	@ invalidate BTC
1030		mcr	p15, 0, r0, c7, c10, 4	@ DSB
1031		mcr	p15, 0, r0, c7, c5, 4	@ ISB
1032		mov	pc, r12
1033
1034/*
1035 * Clean and flush the cache to maintain consistency.
1036 *
1037 * On exit,
1038 *  r1, r2, r3, r9, r10, r11, r12 corrupted
1039 * This routine must preserve:
1040 *  r4, r6, r7, r8
1041 */
1042		.align	5
1043cache_clean_flush:
1044		mov	r3, #16
1045		b	call_cache_fn
1046
1047__armv4_mpu_cache_flush:
1048		mov	r2, #1
1049		mov	r3, #0
1050		mcr	p15, 0, ip, c7, c6, 0	@ invalidate D cache
1051		mov	r1, #7 << 5		@ 8 segments
10521:		orr	r3, r1, #63 << 26	@ 64 entries
10532:		mcr	p15, 0, r3, c7, c14, 2	@ clean & invalidate D index
1054		subs	r3, r3, #1 << 26
1055		bcs	2b			@ entries 63 to 0
1056		subs 	r1, r1, #1 << 5
1057		bcs	1b			@ segments 7 to 0
1058
1059		teq	r2, #0
1060		mcrne	p15, 0, ip, c7, c5, 0	@ invalidate I cache
1061		mcr	p15, 0, ip, c7, c10, 4	@ drain WB
1062		mov	pc, lr
1063
1064__fa526_cache_flush:
1065		mov	r1, #0
1066		mcr	p15, 0, r1, c7, c14, 0	@ clean and invalidate D cache
1067		mcr	p15, 0, r1, c7, c5, 0	@ flush I cache
1068		mcr	p15, 0, r1, c7, c10, 4	@ drain WB
1069		mov	pc, lr
1070
1071__armv6_mmu_cache_flush:
1072		mov	r1, #0
1073		mcr	p15, 0, r1, c7, c14, 0	@ clean+invalidate D
1074		mcr	p15, 0, r1, c7, c5, 0	@ invalidate I+BTB
1075		mcr	p15, 0, r1, c7, c15, 0	@ clean+invalidate unified
1076		mcr	p15, 0, r1, c7, c10, 4	@ drain WB
1077		mov	pc, lr
1078
1079__armv7_mmu_cache_flush:
1080		mrc	p15, 0, r10, c0, c1, 5	@ read ID_MMFR1
1081		tst	r10, #0xf << 16		@ hierarchical cache (ARMv7)
1082		mov	r10, #0
1083		beq	hierarchical
1084		mcr	p15, 0, r10, c7, c14, 0	@ clean+invalidate D
1085		b	iflush
1086hierarchical:
1087		mcr	p15, 0, r10, c7, c10, 5	@ DMB
1088		stmfd	sp!, {r0-r7, r9-r11}
1089		mrc	p15, 1, r0, c0, c0, 1	@ read clidr
1090		ands	r3, r0, #0x7000000	@ extract loc from clidr
1091		mov	r3, r3, lsr #23		@ left align loc bit field
1092		beq	finished		@ if loc is 0, then no need to clean
1093		mov	r10, #0			@ start clean at cache level 0
1094loop1:
1095		add	r2, r10, r10, lsr #1	@ work out 3x current cache level
1096		mov	r1, r0, lsr r2		@ extract cache type bits from clidr
1097		and	r1, r1, #7		@ mask of the bits for current cache only
1098		cmp	r1, #2			@ see what cache we have at this level
1099		blt	skip			@ skip if no cache, or just i-cache
1100		mcr	p15, 2, r10, c0, c0, 0	@ select current cache level in cssr
1101		mcr	p15, 0, r10, c7, c5, 4	@ isb to sych the new cssr&csidr
1102		mrc	p15, 1, r1, c0, c0, 0	@ read the new csidr
1103		and	r2, r1, #7		@ extract the length of the cache lines
1104		add	r2, r2, #4		@ add 4 (line length offset)
1105		ldr	r4, =0x3ff
1106		ands	r4, r4, r1, lsr #3	@ find maximum number on the way size
1107		clz	r5, r4			@ find bit position of way size increment
1108		ldr	r7, =0x7fff
1109		ands	r7, r7, r1, lsr #13	@ extract max number of the index size
1110loop2:
1111		mov	r9, r4			@ create working copy of max way size
1112loop3:
1113 ARM(		orr	r11, r10, r9, lsl r5	) @ factor way and cache number into r11
1114 ARM(		orr	r11, r11, r7, lsl r2	) @ factor index number into r11
1115 THUMB(		lsl	r6, r9, r5		)
1116 THUMB(		orr	r11, r10, r6		) @ factor way and cache number into r11
1117 THUMB(		lsl	r6, r7, r2		)
1118 THUMB(		orr	r11, r11, r6		) @ factor index number into r11
1119		mcr	p15, 0, r11, c7, c14, 2	@ clean & invalidate by set/way
1120		subs	r9, r9, #1		@ decrement the way
1121		bge	loop3
1122		subs	r7, r7, #1		@ decrement the index
1123		bge	loop2
1124skip:
1125		add	r10, r10, #2		@ increment cache number
1126		cmp	r3, r10
1127		bgt	loop1
1128finished:
1129		ldmfd	sp!, {r0-r7, r9-r11}
1130		mov	r10, #0			@ swith back to cache level 0
1131		mcr	p15, 2, r10, c0, c0, 0	@ select current cache level in cssr
1132iflush:
1133		mcr	p15, 0, r10, c7, c10, 4	@ DSB
1134		mcr	p15, 0, r10, c7, c5, 0	@ invalidate I+BTB
1135		mcr	p15, 0, r10, c7, c10, 4	@ DSB
1136		mcr	p15, 0, r10, c7, c5, 4	@ ISB
1137		mov	pc, lr
1138
1139__armv5tej_mmu_cache_flush:
11401:		mrc	p15, 0, r15, c7, c14, 3	@ test,clean,invalidate D cache
1141		bne	1b
1142		mcr	p15, 0, r0, c7, c5, 0	@ flush I cache
1143		mcr	p15, 0, r0, c7, c10, 4	@ drain WB
1144		mov	pc, lr
1145
1146__armv4_mmu_cache_flush:
1147		mov	r2, #64*1024		@ default: 32K dcache size (*2)
1148		mov	r11, #32		@ default: 32 byte line size
1149		mrc	p15, 0, r3, c0, c0, 1	@ read cache type
1150		teq	r3, r9			@ cache ID register present?
1151		beq	no_cache_id
1152		mov	r1, r3, lsr #18
1153		and	r1, r1, #7
1154		mov	r2, #1024
1155		mov	r2, r2, lsl r1		@ base dcache size *2
1156		tst	r3, #1 << 14		@ test M bit
1157		addne	r2, r2, r2, lsr #1	@ +1/2 size if M == 1
1158		mov	r3, r3, lsr #12
1159		and	r3, r3, #3
1160		mov	r11, #8
1161		mov	r11, r11, lsl r3	@ cache line size in bytes
1162no_cache_id:
1163		mov	r1, pc
1164		bic	r1, r1, #63		@ align to longest cache line
1165		add	r2, r1, r2
11661:
1167 ARM(		ldr	r3, [r1], r11		) @ s/w flush D cache
1168 THUMB(		ldr     r3, [r1]		) @ s/w flush D cache
1169 THUMB(		add     r1, r1, r11		)
1170		teq	r1, r2
1171		bne	1b
1172
1173		mcr	p15, 0, r1, c7, c5, 0	@ flush I cache
1174		mcr	p15, 0, r1, c7, c6, 0	@ flush D cache
1175		mcr	p15, 0, r1, c7, c10, 4	@ drain WB
1176		mov	pc, lr
1177
1178__armv3_mmu_cache_flush:
1179__armv3_mpu_cache_flush:
1180		mov	r1, #0
1181		mcr	p15, 0, r1, c7, c0, 0	@ invalidate whole cache v3
1182		mov	pc, lr
1183
1184/*
1185 * Various debugging routines for printing hex characters and
1186 * memory, which again must be relocatable.
1187 */
1188#ifdef DEBUG
1189		.align	2
1190		.type	phexbuf,#object
1191phexbuf:	.space	12
1192		.size	phexbuf, . - phexbuf
1193
1194@ phex corrupts {r0, r1, r2, r3}
1195phex:		adr	r3, phexbuf
1196		mov	r2, #0
1197		strb	r2, [r3, r1]
11981:		subs	r1, r1, #1
1199		movmi	r0, r3
1200		bmi	puts
1201		and	r2, r0, #15
1202		mov	r0, r0, lsr #4
1203		cmp	r2, #10
1204		addge	r2, r2, #7
1205		add	r2, r2, #'0'
1206		strb	r2, [r3, r1]
1207		b	1b
1208
1209@ puts corrupts {r0, r1, r2, r3}
1210puts:		loadsp	r3, r1
12111:		ldrb	r2, [r0], #1
1212		teq	r2, #0
1213		moveq	pc, lr
12142:		writeb	r2, r3
1215		mov	r1, #0x00020000
12163:		subs	r1, r1, #1
1217		bne	3b
1218		teq	r2, #'\n'
1219		moveq	r2, #'\r'
1220		beq	2b
1221		teq	r0, #0
1222		bne	1b
1223		mov	pc, lr
1224@ putc corrupts {r0, r1, r2, r3}
1225putc:
1226		mov	r2, r0
1227		mov	r0, #0
1228		loadsp	r3, r1
1229		b	2b
1230
1231@ memdump corrupts {r0, r1, r2, r3, r10, r11, r12, lr}
1232memdump:	mov	r12, r0
1233		mov	r10, lr
1234		mov	r11, #0
12352:		mov	r0, r11, lsl #2
1236		add	r0, r0, r12
1237		mov	r1, #8
1238		bl	phex
1239		mov	r0, #':'
1240		bl	putc
12411:		mov	r0, #' '
1242		bl	putc
1243		ldr	r0, [r12, r11, lsl #2]
1244		mov	r1, #8
1245		bl	phex
1246		and	r0, r11, #7
1247		teq	r0, #3
1248		moveq	r0, #' '
1249		bleq	putc
1250		and	r0, r11, #7
1251		add	r11, r11, #1
1252		teq	r0, #7
1253		bne	1b
1254		mov	r0, #'\n'
1255		bl	putc
1256		cmp	r11, #64
1257		blt	2b
1258		mov	pc, r10
1259#endif
1260
1261		.ltorg
1262
1263#ifdef CONFIG_ARM_VIRT_EXT
1264.align 5
1265__hyp_reentry_vectors:
1266		W(b)	.			@ reset
1267		W(b)	.			@ undef
1268		W(b)	.			@ svc
1269		W(b)	.			@ pabort
1270		W(b)	.			@ dabort
1271		W(b)	__enter_kernel		@ hyp
1272		W(b)	.			@ irq
1273		W(b)	.			@ fiq
1274#endif /* CONFIG_ARM_VIRT_EXT */
1275
1276__enter_kernel:
1277		mov	r0, #0			@ must be 0
1278 ARM(		mov	pc, r4	)		@ call kernel
1279 THUMB(		bx	r4	)		@ entry point is always ARM
1280
1281reloc_code_end:
1282
1283		.align
1284		.section ".stack", "aw", %nobits
1285.L_user_stack:	.space	4096
1286.L_user_stack_end:
1287