xref: /openbmc/linux/arch/arm/boot/compressed/head.S (revision ced2a3b8)
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#elif defined(CONFIG_ARCH_S3C24XX)
64		.macro loadsp, rb, tmp
65		mov	\rb, #0x50000000
66		add	\rb, \rb, #0x4000 * CONFIG_S3C_LOWLEVEL_UART_PORT
67		.endm
68#else
69		.macro	loadsp,	rb, tmp
70		addruart \rb, \tmp
71		.endm
72#endif
73#endif
74#endif
75
76		.macro	kputc,val
77		mov	r0, \val
78		bl	putc
79		.endm
80
81		.macro	kphex,val,len
82		mov	r0, \val
83		mov	r1, #\len
84		bl	phex
85		.endm
86
87		.macro	debug_reloc_start
88#ifdef DEBUG
89		kputc	#'\n'
90		kphex	r6, 8		/* processor id */
91		kputc	#':'
92		kphex	r7, 8		/* architecture id */
93#ifdef CONFIG_CPU_CP15
94		kputc	#':'
95		mrc	p15, 0, r0, c1, c0
96		kphex	r0, 8		/* control reg */
97#endif
98		kputc	#'\n'
99		kphex	r5, 8		/* decompressed kernel start */
100		kputc	#'-'
101		kphex	r9, 8		/* decompressed kernel end  */
102		kputc	#'>'
103		kphex	r4, 8		/* kernel execution address */
104		kputc	#'\n'
105#endif
106		.endm
107
108		.macro	debug_reloc_end
109#ifdef DEBUG
110		kphex	r5, 8		/* end of kernel */
111		kputc	#'\n'
112		mov	r0, r4
113		bl	memdump		/* dump 256 bytes at start of kernel */
114#endif
115		.endm
116
117		.section ".start", #alloc, #execinstr
118/*
119 * sort out different calling conventions
120 */
121		.align
122		.arm				@ Always enter in ARM state
123start:
124		.type	start,#function
125		.rept	7
126		mov	r0, r0
127		.endr
128   ARM(		mov	r0, r0		)
129   ARM(		b	1f		)
130 THUMB(		adr	r12, BSYM(1f)	)
131 THUMB(		bx	r12		)
132
133		.word	0x016f2818		@ Magic numbers to help the loader
134		.word	start			@ absolute load/run zImage address
135		.word	_edata			@ zImage end address
136 THUMB(		.thumb			)
1371:
138		mrs	r9, cpsr
139#ifdef CONFIG_ARM_VIRT_EXT
140		bl	__hyp_stub_install	@ get into SVC mode, reversibly
141#endif
142		mov	r7, r1			@ save architecture ID
143		mov	r8, r2			@ save atags pointer
144
145#ifndef __ARM_ARCH_2__
146		/*
147		 * Booting from Angel - need to enter SVC mode and disable
148		 * FIQs/IRQs (numeric definitions from angel arm.h source).
149		 * We only do this if we were in user mode on entry.
150		 */
151		mrs	r2, cpsr		@ get current mode
152		tst	r2, #3			@ not user?
153		bne	not_angel
154		mov	r0, #0x17		@ angel_SWIreason_EnterSVC
155 ARM(		swi	0x123456	)	@ angel_SWI_ARM
156 THUMB(		svc	0xab		)	@ angel_SWI_THUMB
157not_angel:
158		safe_svcmode_maskall r0
159		msr	spsr_cxsf, r9		@ Save the CPU boot mode in
160						@ SPSR
161#else
162		teqp	pc, #0x0c000003		@ turn off interrupts
163#endif
164
165		/*
166		 * Note that some cache flushing and other stuff may
167		 * be needed here - is there an Angel SWI call for this?
168		 */
169
170		/*
171		 * some architecture specific code can be inserted
172		 * by the linker here, but it should preserve r7, r8, and r9.
173		 */
174
175		.text
176
177#ifdef CONFIG_AUTO_ZRELADDR
178		@ determine final kernel image address
179		mov	r4, pc
180		and	r4, r4, #0xf8000000
181		add	r4, r4, #TEXT_OFFSET
182#else
183		ldr	r4, =zreladdr
184#endif
185
186		bl	cache_on
187
188restart:	adr	r0, LC0
189		ldmia	r0, {r1, r2, r3, r6, r10, r11, r12}
190		ldr	sp, [r0, #28]
191
192		/*
193		 * We might be running at a different address.  We need
194		 * to fix up various pointers.
195		 */
196		sub	r0, r0, r1		@ calculate the delta offset
197		add	r6, r6, r0		@ _edata
198		add	r10, r10, r0		@ inflated kernel size location
199
200		/*
201		 * The kernel build system appends the size of the
202		 * decompressed kernel at the end of the compressed data
203		 * in little-endian form.
204		 */
205		ldrb	r9, [r10, #0]
206		ldrb	lr, [r10, #1]
207		orr	r9, r9, lr, lsl #8
208		ldrb	lr, [r10, #2]
209		ldrb	r10, [r10, #3]
210		orr	r9, r9, lr, lsl #16
211		orr	r9, r9, r10, lsl #24
212
213#ifndef CONFIG_ZBOOT_ROM
214		/* malloc space is above the relocated stack (64k max) */
215		add	sp, sp, r0
216		add	r10, sp, #0x10000
217#else
218		/*
219		 * With ZBOOT_ROM the bss/stack is non relocatable,
220		 * but someone could still run this code from RAM,
221		 * in which case our reference is _edata.
222		 */
223		mov	r10, r6
224#endif
225
226		mov	r5, #0			@ init dtb size to 0
227#ifdef CONFIG_ARM_APPENDED_DTB
228/*
229 *   r0  = delta
230 *   r2  = BSS start
231 *   r3  = BSS end
232 *   r4  = final kernel address
233 *   r5  = appended dtb size (still unknown)
234 *   r6  = _edata
235 *   r7  = architecture ID
236 *   r8  = atags/device tree pointer
237 *   r9  = size of decompressed image
238 *   r10 = end of this image, including  bss/stack/malloc space if non XIP
239 *   r11 = GOT start
240 *   r12 = GOT end
241 *   sp  = stack pointer
242 *
243 * if there are device trees (dtb) appended to zImage, advance r10 so that the
244 * dtb data will get relocated along with the kernel if necessary.
245 */
246
247		ldr	lr, [r6, #0]
248#ifndef __ARMEB__
249		ldr	r1, =0xedfe0dd0		@ sig is 0xd00dfeed big endian
250#else
251		ldr	r1, =0xd00dfeed
252#endif
253		cmp	lr, r1
254		bne	dtb_check_done		@ not found
255
256#ifdef CONFIG_ARM_ATAG_DTB_COMPAT
257		/*
258		 * OK... Let's do some funky business here.
259		 * If we do have a DTB appended to zImage, and we do have
260		 * an ATAG list around, we want the later to be translated
261		 * and folded into the former here.  To be on the safe side,
262		 * let's temporarily move  the stack away into the malloc
263		 * area.  No GOT fixup has occurred yet, but none of the
264		 * code we're about to call uses any global variable.
265		*/
266		add	sp, sp, #0x10000
267		stmfd	sp!, {r0-r3, ip, lr}
268		mov	r0, r8
269		mov	r1, r6
270		sub	r2, sp, r6
271		bl	atags_to_fdt
272
273		/*
274		 * If returned value is 1, there is no ATAG at the location
275		 * pointed by r8.  Try the typical 0x100 offset from start
276		 * of RAM and hope for the best.
277		 */
278		cmp	r0, #1
279		sub	r0, r4, #TEXT_OFFSET
280		add	r0, r0, #0x100
281		mov	r1, r6
282		sub	r2, sp, r6
283		bleq	atags_to_fdt
284
285		ldmfd	sp!, {r0-r3, ip, lr}
286		sub	sp, sp, #0x10000
287#endif
288
289		mov	r8, r6			@ use the appended device tree
290
291		/*
292		 * Make sure that the DTB doesn't end up in the final
293		 * kernel's .bss area. To do so, we adjust the decompressed
294		 * kernel size to compensate if that .bss size is larger
295		 * than the relocated code.
296		 */
297		ldr	r5, =_kernel_bss_size
298		adr	r1, wont_overwrite
299		sub	r1, r6, r1
300		subs	r1, r5, r1
301		addhi	r9, r9, r1
302
303		/* Get the dtb's size */
304		ldr	r5, [r6, #4]
305#ifndef __ARMEB__
306		/* convert r5 (dtb size) to little endian */
307		eor	r1, r5, r5, ror #16
308		bic	r1, r1, #0x00ff0000
309		mov	r5, r5, ror #8
310		eor	r5, r5, r1, lsr #8
311#endif
312
313		/* preserve 64-bit alignment */
314		add	r5, r5, #7
315		bic	r5, r5, #7
316
317		/* relocate some pointers past the appended dtb */
318		add	r6, r6, r5
319		add	r10, r10, r5
320		add	sp, sp, r5
321dtb_check_done:
322#endif
323
324/*
325 * Check to see if we will overwrite ourselves.
326 *   r4  = final kernel address
327 *   r9  = size of decompressed image
328 *   r10 = end of this image, including  bss/stack/malloc space if non XIP
329 * We basically want:
330 *   r4 - 16k page directory >= r10 -> OK
331 *   r4 + image length <= address of wont_overwrite -> OK
332 */
333		add	r10, r10, #16384
334		cmp	r4, r10
335		bhs	wont_overwrite
336		add	r10, r4, r9
337		adr	r9, wont_overwrite
338		cmp	r10, r9
339		bls	wont_overwrite
340
341/*
342 * Relocate ourselves past the end of the decompressed kernel.
343 *   r6  = _edata
344 *   r10 = end of the decompressed kernel
345 * Because we always copy ahead, we need to do it from the end and go
346 * backward in case the source and destination overlap.
347 */
348		/*
349		 * Bump to the next 256-byte boundary with the size of
350		 * the relocation code added. This avoids overwriting
351		 * ourself when the offset is small.
352		 */
353		add	r10, r10, #((reloc_code_end - restart + 256) & ~255)
354		bic	r10, r10, #255
355
356		/* Get start of code we want to copy and align it down. */
357		adr	r5, restart
358		bic	r5, r5, #31
359
360/* Relocate the hyp vector base if necessary */
361#ifdef CONFIG_ARM_VIRT_EXT
362		mrs	r0, spsr
363		and	r0, r0, #MODE_MASK
364		cmp	r0, #HYP_MODE
365		bne	1f
366
367		bl	__hyp_get_vectors
368		sub	r0, r0, r5
369		add	r0, r0, r10
370		bl	__hyp_set_vectors
3711:
372#endif
373
374		sub	r9, r6, r5		@ size to copy
375		add	r9, r9, #31		@ rounded up to a multiple
376		bic	r9, r9, #31		@ ... of 32 bytes
377		add	r6, r9, r5
378		add	r9, r9, r10
379
3801:		ldmdb	r6!, {r0 - r3, r10 - r12, lr}
381		cmp	r6, r5
382		stmdb	r9!, {r0 - r3, r10 - r12, lr}
383		bhi	1b
384
385		/* Preserve offset to relocated code. */
386		sub	r6, r9, r6
387
388#ifndef CONFIG_ZBOOT_ROM
389		/* cache_clean_flush may use the stack, so relocate it */
390		add	sp, sp, r6
391#endif
392
393		bl	cache_clean_flush
394
395		adr	r0, BSYM(restart)
396		add	r0, r0, r6
397		mov	pc, r0
398
399wont_overwrite:
400/*
401 * If delta is zero, we are running at the address we were linked at.
402 *   r0  = delta
403 *   r2  = BSS start
404 *   r3  = BSS end
405 *   r4  = kernel execution address
406 *   r5  = appended dtb size (0 if not present)
407 *   r7  = architecture ID
408 *   r8  = atags pointer
409 *   r11 = GOT start
410 *   r12 = GOT end
411 *   sp  = stack pointer
412 */
413		orrs	r1, r0, r5
414		beq	not_relocated
415
416		add	r11, r11, r0
417		add	r12, r12, r0
418
419#ifndef CONFIG_ZBOOT_ROM
420		/*
421		 * If we're running fully PIC === CONFIG_ZBOOT_ROM = n,
422		 * we need to fix up pointers into the BSS region.
423		 * Note that the stack pointer has already been fixed up.
424		 */
425		add	r2, r2, r0
426		add	r3, r3, r0
427
428		/*
429		 * Relocate all entries in the GOT table.
430		 * Bump bss entries to _edata + dtb size
431		 */
4321:		ldr	r1, [r11, #0]		@ relocate entries in the GOT
433		add	r1, r1, r0		@ This fixes up C references
434		cmp	r1, r2			@ if entry >= bss_start &&
435		cmphs	r3, r1			@       bss_end > entry
436		addhi	r1, r1, r5		@    entry += dtb size
437		str	r1, [r11], #4		@ next entry
438		cmp	r11, r12
439		blo	1b
440
441		/* bump our bss pointers too */
442		add	r2, r2, r5
443		add	r3, r3, r5
444
445#else
446
447		/*
448		 * Relocate entries in the GOT table.  We only relocate
449		 * the entries that are outside the (relocated) BSS region.
450		 */
4511:		ldr	r1, [r11, #0]		@ relocate entries in the GOT
452		cmp	r1, r2			@ entry < bss_start ||
453		cmphs	r3, r1			@ _end < entry
454		addlo	r1, r1, r0		@ table.  This fixes up the
455		str	r1, [r11], #4		@ C references.
456		cmp	r11, r12
457		blo	1b
458#endif
459
460not_relocated:	mov	r0, #0
4611:		str	r0, [r2], #4		@ clear bss
462		str	r0, [r2], #4
463		str	r0, [r2], #4
464		str	r0, [r2], #4
465		cmp	r2, r3
466		blo	1b
467
468/*
469 * The C runtime environment should now be setup sufficiently.
470 * Set up some pointers, and start decompressing.
471 *   r4  = kernel execution address
472 *   r7  = architecture ID
473 *   r8  = atags pointer
474 */
475		mov	r0, r4
476		mov	r1, sp			@ malloc space above stack
477		add	r2, sp, #0x10000	@ 64k max
478		mov	r3, r7
479		bl	decompress_kernel
480		bl	cache_clean_flush
481		bl	cache_off
482		mov	r1, r7			@ restore architecture number
483		mov	r2, r8			@ restore atags pointer
484
485#ifdef CONFIG_ARM_VIRT_EXT
486		mrs	r0, spsr		@ Get saved CPU boot mode
487		and	r0, r0, #MODE_MASK
488		cmp	r0, #HYP_MODE		@ if not booted in HYP mode...
489		bne	__enter_kernel		@ boot kernel directly
490
491		adr	r12, .L__hyp_reentry_vectors_offset
492		ldr	r0, [r12]
493		add	r0, r0, r12
494
495		bl	__hyp_set_vectors
496		__HVC(0)			@ otherwise bounce to hyp mode
497
498		b	.			@ should never be reached
499
500		.align	2
501.L__hyp_reentry_vectors_offset:	.long	__hyp_reentry_vectors - .
502#else
503		b	__enter_kernel
504#endif
505
506		.align	2
507		.type	LC0, #object
508LC0:		.word	LC0			@ r1
509		.word	__bss_start		@ r2
510		.word	_end			@ r3
511		.word	_edata			@ r6
512		.word	input_data_end - 4	@ r10 (inflated size location)
513		.word	_got_start		@ r11
514		.word	_got_end		@ ip
515		.word	.L_user_stack_end	@ sp
516		.size	LC0, . - LC0
517
518#ifdef CONFIG_ARCH_RPC
519		.globl	params
520params:		ldr	r0, =0x10000100		@ params_phys for RPC
521		mov	pc, lr
522		.ltorg
523		.align
524#endif
525
526/*
527 * Turn on the cache.  We need to setup some page tables so that we
528 * can have both the I and D caches on.
529 *
530 * We place the page tables 16k down from the kernel execution address,
531 * and we hope that nothing else is using it.  If we're using it, we
532 * will go pop!
533 *
534 * On entry,
535 *  r4 = kernel execution address
536 *  r7 = architecture number
537 *  r8 = atags pointer
538 * On exit,
539 *  r0, r1, r2, r3, r9, r10, r12 corrupted
540 * This routine must preserve:
541 *  r4, r7, r8
542 */
543		.align	5
544cache_on:	mov	r3, #8			@ cache_on function
545		b	call_cache_fn
546
547/*
548 * Initialize the highest priority protection region, PR7
549 * to cover all 32bit address and cacheable and bufferable.
550 */
551__armv4_mpu_cache_on:
552		mov	r0, #0x3f		@ 4G, the whole
553		mcr	p15, 0, r0, c6, c7, 0	@ PR7 Area Setting
554		mcr 	p15, 0, r0, c6, c7, 1
555
556		mov	r0, #0x80		@ PR7
557		mcr	p15, 0, r0, c2, c0, 0	@ D-cache on
558		mcr	p15, 0, r0, c2, c0, 1	@ I-cache on
559		mcr	p15, 0, r0, c3, c0, 0	@ write-buffer on
560
561		mov	r0, #0xc000
562		mcr	p15, 0, r0, c5, c0, 1	@ I-access permission
563		mcr	p15, 0, r0, c5, c0, 0	@ D-access permission
564
565		mov	r0, #0
566		mcr	p15, 0, r0, c7, c10, 4	@ drain write buffer
567		mcr	p15, 0, r0, c7, c5, 0	@ flush(inval) I-Cache
568		mcr	p15, 0, r0, c7, c6, 0	@ flush(inval) D-Cache
569		mrc	p15, 0, r0, c1, c0, 0	@ read control reg
570						@ ...I .... ..D. WC.M
571		orr	r0, r0, #0x002d		@ .... .... ..1. 11.1
572		orr	r0, r0, #0x1000		@ ...1 .... .... ....
573
574		mcr	p15, 0, r0, c1, c0, 0	@ write control reg
575
576		mov	r0, #0
577		mcr	p15, 0, r0, c7, c5, 0	@ flush(inval) I-Cache
578		mcr	p15, 0, r0, c7, c6, 0	@ flush(inval) D-Cache
579		mov	pc, lr
580
581__armv3_mpu_cache_on:
582		mov	r0, #0x3f		@ 4G, the whole
583		mcr	p15, 0, r0, c6, c7, 0	@ PR7 Area Setting
584
585		mov	r0, #0x80		@ PR7
586		mcr	p15, 0, r0, c2, c0, 0	@ cache on
587		mcr	p15, 0, r0, c3, c0, 0	@ write-buffer on
588
589		mov	r0, #0xc000
590		mcr	p15, 0, r0, c5, c0, 0	@ access permission
591
592		mov	r0, #0
593		mcr	p15, 0, r0, c7, c0, 0	@ invalidate whole cache v3
594		/*
595		 * ?? ARMv3 MMU does not allow reading the control register,
596		 * does this really work on ARMv3 MPU?
597		 */
598		mrc	p15, 0, r0, c1, c0, 0	@ read control reg
599						@ .... .... .... WC.M
600		orr	r0, r0, #0x000d		@ .... .... .... 11.1
601		/* ?? this overwrites the value constructed above? */
602		mov	r0, #0
603		mcr	p15, 0, r0, c1, c0, 0	@ write control reg
604
605		/* ?? invalidate for the second time? */
606		mcr	p15, 0, r0, c7, c0, 0	@ invalidate whole cache v3
607		mov	pc, lr
608
609#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
610#define CB_BITS 0x08
611#else
612#define CB_BITS 0x0c
613#endif
614
615__setup_mmu:	sub	r3, r4, #16384		@ Page directory size
616		bic	r3, r3, #0xff		@ Align the pointer
617		bic	r3, r3, #0x3f00
618/*
619 * Initialise the page tables, turning on the cacheable and bufferable
620 * bits for the RAM area only.
621 */
622		mov	r0, r3
623		mov	r9, r0, lsr #18
624		mov	r9, r9, lsl #18		@ start of RAM
625		add	r10, r9, #0x10000000	@ a reasonable RAM size
626		mov	r1, #0x12		@ XN|U + section mapping
627		orr	r1, r1, #3 << 10	@ AP=11
628		add	r2, r3, #16384
6291:		cmp	r1, r9			@ if virt > start of RAM
630		cmphs	r10, r1			@   && end of RAM > virt
631		bic	r1, r1, #0x1c		@ clear XN|U + C + B
632		orrlo	r1, r1, #0x10		@ Set XN|U for non-RAM
633		orrhs	r1, r1, r6		@ set RAM section settings
634		str	r1, [r0], #4		@ 1:1 mapping
635		add	r1, r1, #1048576
636		teq	r0, r2
637		bne	1b
638/*
639 * If ever we are running from Flash, then we surely want the cache
640 * to be enabled also for our execution instance...  We map 2MB of it
641 * so there is no map overlap problem for up to 1 MB compressed kernel.
642 * If the execution is in RAM then we would only be duplicating the above.
643 */
644		orr	r1, r6, #0x04		@ ensure B is set for this
645		orr	r1, r1, #3 << 10
646		mov	r2, pc
647		mov	r2, r2, lsr #20
648		orr	r1, r1, r2, lsl #20
649		add	r0, r3, r2, lsl #2
650		str	r1, [r0], #4
651		add	r1, r1, #1048576
652		str	r1, [r0]
653		mov	pc, lr
654ENDPROC(__setup_mmu)
655
656@ Enable unaligned access on v6, to allow better code generation
657@ for the decompressor C code:
658__armv6_mmu_cache_on:
659		mrc	p15, 0, r0, c1, c0, 0	@ read SCTLR
660		bic	r0, r0, #2		@ A (no unaligned access fault)
661		orr	r0, r0, #1 << 22	@ U (v6 unaligned access model)
662		mcr	p15, 0, r0, c1, c0, 0	@ write SCTLR
663		b	__armv4_mmu_cache_on
664
665__arm926ejs_mmu_cache_on:
666#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
667		mov	r0, #4			@ put dcache in WT mode
668		mcr	p15, 7, r0, c15, c0, 0
669#endif
670
671__armv4_mmu_cache_on:
672		mov	r12, lr
673#ifdef CONFIG_MMU
674		mov	r6, #CB_BITS | 0x12	@ U
675		bl	__setup_mmu
676		mov	r0, #0
677		mcr	p15, 0, r0, c7, c10, 4	@ drain write buffer
678		mcr	p15, 0, r0, c8, c7, 0	@ flush I,D TLBs
679		mrc	p15, 0, r0, c1, c0, 0	@ read control reg
680		orr	r0, r0, #0x5000		@ I-cache enable, RR cache replacement
681		orr	r0, r0, #0x0030
682#ifdef CONFIG_CPU_ENDIAN_BE8
683		orr	r0, r0, #1 << 25	@ big-endian page tables
684#endif
685		bl	__common_mmu_cache_on
686		mov	r0, #0
687		mcr	p15, 0, r0, c8, c7, 0	@ flush I,D TLBs
688#endif
689		mov	pc, r12
690
691__armv7_mmu_cache_on:
692		mov	r12, lr
693#ifdef CONFIG_MMU
694		mrc	p15, 0, r11, c0, c1, 4	@ read ID_MMFR0
695		tst	r11, #0xf		@ VMSA
696		movne	r6, #CB_BITS | 0x02	@ !XN
697		blne	__setup_mmu
698		mov	r0, #0
699		mcr	p15, 0, r0, c7, c10, 4	@ drain write buffer
700		tst	r11, #0xf		@ VMSA
701		mcrne	p15, 0, r0, c8, c7, 0	@ flush I,D TLBs
702#endif
703		mrc	p15, 0, r0, c1, c0, 0	@ read control reg
704		bic	r0, r0, #1 << 28	@ clear SCTLR.TRE
705		orr	r0, r0, #0x5000		@ I-cache enable, RR cache replacement
706		orr	r0, r0, #0x003c		@ write buffer
707		bic	r0, r0, #2		@ A (no unaligned access fault)
708		orr	r0, r0, #1 << 22	@ U (v6 unaligned access model)
709						@ (needed for ARM1176)
710#ifdef CONFIG_MMU
711#ifdef CONFIG_CPU_ENDIAN_BE8
712		orr	r0, r0, #1 << 25	@ big-endian page tables
713#endif
714		mrcne   p15, 0, r6, c2, c0, 2   @ read ttb control reg
715		orrne	r0, r0, #1		@ MMU enabled
716		movne	r1, #0xfffffffd		@ domain 0 = client
717		bic     r6, r6, #1 << 31        @ 32-bit translation system
718		bic     r6, r6, #3 << 0         @ use only ttbr0
719		mcrne	p15, 0, r3, c2, c0, 0	@ load page table pointer
720		mcrne	p15, 0, r1, c3, c0, 0	@ load domain access control
721		mcrne   p15, 0, r6, c2, c0, 2   @ load ttb control
722#endif
723		mcr	p15, 0, r0, c7, c5, 4	@ ISB
724		mcr	p15, 0, r0, c1, c0, 0	@ load control register
725		mrc	p15, 0, r0, c1, c0, 0	@ and read it back
726		mov	r0, #0
727		mcr	p15, 0, r0, c7, c5, 4	@ ISB
728		mov	pc, r12
729
730__fa526_cache_on:
731		mov	r12, lr
732		mov	r6, #CB_BITS | 0x12	@ U
733		bl	__setup_mmu
734		mov	r0, #0
735		mcr	p15, 0, r0, c7, c7, 0	@ Invalidate whole cache
736		mcr	p15, 0, r0, c7, c10, 4	@ drain write buffer
737		mcr	p15, 0, r0, c8, c7, 0	@ flush UTLB
738		mrc	p15, 0, r0, c1, c0, 0	@ read control reg
739		orr	r0, r0, #0x1000		@ I-cache enable
740		bl	__common_mmu_cache_on
741		mov	r0, #0
742		mcr	p15, 0, r0, c8, c7, 0	@ flush UTLB
743		mov	pc, r12
744
745__common_mmu_cache_on:
746#ifndef CONFIG_THUMB2_KERNEL
747#ifndef DEBUG
748		orr	r0, r0, #0x000d		@ Write buffer, mmu
749#endif
750		mov	r1, #-1
751		mcr	p15, 0, r3, c2, c0, 0	@ load page table pointer
752		mcr	p15, 0, r1, c3, c0, 0	@ load domain access control
753		b	1f
754		.align	5			@ cache line aligned
7551:		mcr	p15, 0, r0, c1, c0, 0	@ load control register
756		mrc	p15, 0, r0, c1, c0, 0	@ and read it back to
757		sub	pc, lr, r0, lsr #32	@ properly flush pipeline
758#endif
759
760#define PROC_ENTRY_SIZE (4*5)
761
762/*
763 * Here follow the relocatable cache support functions for the
764 * various processors.  This is a generic hook for locating an
765 * entry and jumping to an instruction at the specified offset
766 * from the start of the block.  Please note this is all position
767 * independent code.
768 *
769 *  r1  = corrupted
770 *  r2  = corrupted
771 *  r3  = block offset
772 *  r9  = corrupted
773 *  r12 = corrupted
774 */
775
776call_cache_fn:	adr	r12, proc_types
777#ifdef CONFIG_CPU_CP15
778		mrc	p15, 0, r9, c0, c0	@ get processor ID
779#else
780		ldr	r9, =CONFIG_PROCESSOR_ID
781#endif
7821:		ldr	r1, [r12, #0]		@ get value
783		ldr	r2, [r12, #4]		@ get mask
784		eor	r1, r1, r9		@ (real ^ match)
785		tst	r1, r2			@       & mask
786 ARM(		addeq	pc, r12, r3		) @ call cache function
787 THUMB(		addeq	r12, r3			)
788 THUMB(		moveq	pc, r12			) @ call cache function
789		add	r12, r12, #PROC_ENTRY_SIZE
790		b	1b
791
792/*
793 * Table for cache operations.  This is basically:
794 *   - CPU ID match
795 *   - CPU ID mask
796 *   - 'cache on' method instruction
797 *   - 'cache off' method instruction
798 *   - 'cache flush' method instruction
799 *
800 * We match an entry using: ((real_id ^ match) & mask) == 0
801 *
802 * Writethrough caches generally only need 'on' and 'off'
803 * methods.  Writeback caches _must_ have the flush method
804 * defined.
805 */
806		.align	2
807		.type	proc_types,#object
808proc_types:
809		.word	0x41000000		@ old ARM ID
810		.word	0xff00f000
811		mov	pc, lr
812 THUMB(		nop				)
813		mov	pc, lr
814 THUMB(		nop				)
815		mov	pc, lr
816 THUMB(		nop				)
817
818		.word	0x41007000		@ ARM7/710
819		.word	0xfff8fe00
820		mov	pc, lr
821 THUMB(		nop				)
822		mov	pc, lr
823 THUMB(		nop				)
824		mov	pc, lr
825 THUMB(		nop				)
826
827		.word	0x41807200		@ ARM720T (writethrough)
828		.word	0xffffff00
829		W(b)	__armv4_mmu_cache_on
830		W(b)	__armv4_mmu_cache_off
831		mov	pc, lr
832 THUMB(		nop				)
833
834		.word	0x41007400		@ ARM74x
835		.word	0xff00ff00
836		W(b)	__armv3_mpu_cache_on
837		W(b)	__armv3_mpu_cache_off
838		W(b)	__armv3_mpu_cache_flush
839
840		.word	0x41009400		@ ARM94x
841		.word	0xff00ff00
842		W(b)	__armv4_mpu_cache_on
843		W(b)	__armv4_mpu_cache_off
844		W(b)	__armv4_mpu_cache_flush
845
846		.word	0x41069260		@ ARM926EJ-S (v5TEJ)
847		.word	0xff0ffff0
848		W(b)	__arm926ejs_mmu_cache_on
849		W(b)	__armv4_mmu_cache_off
850		W(b)	__armv5tej_mmu_cache_flush
851
852		.word	0x00007000		@ ARM7 IDs
853		.word	0x0000f000
854		mov	pc, lr
855 THUMB(		nop				)
856		mov	pc, lr
857 THUMB(		nop				)
858		mov	pc, lr
859 THUMB(		nop				)
860
861		@ Everything from here on will be the new ID system.
862
863		.word	0x4401a100		@ sa110 / sa1100
864		.word	0xffffffe0
865		W(b)	__armv4_mmu_cache_on
866		W(b)	__armv4_mmu_cache_off
867		W(b)	__armv4_mmu_cache_flush
868
869		.word	0x6901b110		@ sa1110
870		.word	0xfffffff0
871		W(b)	__armv4_mmu_cache_on
872		W(b)	__armv4_mmu_cache_off
873		W(b)	__armv4_mmu_cache_flush
874
875		.word	0x56056900
876		.word	0xffffff00		@ PXA9xx
877		W(b)	__armv4_mmu_cache_on
878		W(b)	__armv4_mmu_cache_off
879		W(b)	__armv4_mmu_cache_flush
880
881		.word	0x56158000		@ PXA168
882		.word	0xfffff000
883		W(b)	__armv4_mmu_cache_on
884		W(b)	__armv4_mmu_cache_off
885		W(b)	__armv5tej_mmu_cache_flush
886
887		.word	0x56050000		@ Feroceon
888		.word	0xff0f0000
889		W(b)	__armv4_mmu_cache_on
890		W(b)	__armv4_mmu_cache_off
891		W(b)	__armv5tej_mmu_cache_flush
892
893#ifdef CONFIG_CPU_FEROCEON_OLD_ID
894		/* this conflicts with the standard ARMv5TE entry */
895		.long	0x41009260		@ Old Feroceon
896		.long	0xff00fff0
897		b	__armv4_mmu_cache_on
898		b	__armv4_mmu_cache_off
899		b	__armv5tej_mmu_cache_flush
900#endif
901
902		.word	0x66015261		@ FA526
903		.word	0xff01fff1
904		W(b)	__fa526_cache_on
905		W(b)	__armv4_mmu_cache_off
906		W(b)	__fa526_cache_flush
907
908		@ These match on the architecture ID
909
910		.word	0x00020000		@ ARMv4T
911		.word	0x000f0000
912		W(b)	__armv4_mmu_cache_on
913		W(b)	__armv4_mmu_cache_off
914		W(b)	__armv4_mmu_cache_flush
915
916		.word	0x00050000		@ ARMv5TE
917		.word	0x000f0000
918		W(b)	__armv4_mmu_cache_on
919		W(b)	__armv4_mmu_cache_off
920		W(b)	__armv4_mmu_cache_flush
921
922		.word	0x00060000		@ ARMv5TEJ
923		.word	0x000f0000
924		W(b)	__armv4_mmu_cache_on
925		W(b)	__armv4_mmu_cache_off
926		W(b)	__armv5tej_mmu_cache_flush
927
928		.word	0x0007b000		@ ARMv6
929		.word	0x000ff000
930		W(b)	__armv6_mmu_cache_on
931		W(b)	__armv4_mmu_cache_off
932		W(b)	__armv6_mmu_cache_flush
933
934		.word	0x000f0000		@ new CPU Id
935		.word	0x000f0000
936		W(b)	__armv7_mmu_cache_on
937		W(b)	__armv7_mmu_cache_off
938		W(b)	__armv7_mmu_cache_flush
939
940		.word	0			@ unrecognised type
941		.word	0
942		mov	pc, lr
943 THUMB(		nop				)
944		mov	pc, lr
945 THUMB(		nop				)
946		mov	pc, lr
947 THUMB(		nop				)
948
949		.size	proc_types, . - proc_types
950
951		/*
952		 * If you get a "non-constant expression in ".if" statement"
953		 * error from the assembler on this line, check that you have
954		 * not accidentally written a "b" instruction where you should
955		 * have written W(b).
956		 */
957		.if (. - proc_types) % PROC_ENTRY_SIZE != 0
958		.error "The size of one or more proc_types entries is wrong."
959		.endif
960
961/*
962 * Turn off the Cache and MMU.  ARMv3 does not support
963 * reading the control register, but ARMv4 does.
964 *
965 * On exit,
966 *  r0, r1, r2, r3, r9, r12 corrupted
967 * This routine must preserve:
968 *  r4, r7, r8
969 */
970		.align	5
971cache_off:	mov	r3, #12			@ cache_off function
972		b	call_cache_fn
973
974__armv4_mpu_cache_off:
975		mrc	p15, 0, r0, c1, c0
976		bic	r0, r0, #0x000d
977		mcr	p15, 0, r0, c1, c0	@ turn MPU and cache off
978		mov	r0, #0
979		mcr	p15, 0, r0, c7, c10, 4	@ drain write buffer
980		mcr	p15, 0, r0, c7, c6, 0	@ flush D-Cache
981		mcr	p15, 0, r0, c7, c5, 0	@ flush I-Cache
982		mov	pc, lr
983
984__armv3_mpu_cache_off:
985		mrc	p15, 0, r0, c1, c0
986		bic	r0, r0, #0x000d
987		mcr	p15, 0, r0, c1, c0, 0	@ turn MPU and cache off
988		mov	r0, #0
989		mcr	p15, 0, r0, c7, c0, 0	@ invalidate whole cache v3
990		mov	pc, lr
991
992__armv4_mmu_cache_off:
993#ifdef CONFIG_MMU
994		mrc	p15, 0, r0, c1, c0
995		bic	r0, r0, #0x000d
996		mcr	p15, 0, r0, c1, c0	@ turn MMU and cache off
997		mov	r0, #0
998		mcr	p15, 0, r0, c7, c7	@ invalidate whole cache v4
999		mcr	p15, 0, r0, c8, c7	@ invalidate whole TLB v4
1000#endif
1001		mov	pc, lr
1002
1003__armv7_mmu_cache_off:
1004		mrc	p15, 0, r0, c1, c0
1005#ifdef CONFIG_MMU
1006		bic	r0, r0, #0x000d
1007#else
1008		bic	r0, r0, #0x000c
1009#endif
1010		mcr	p15, 0, r0, c1, c0	@ turn MMU and cache off
1011		mov	r12, lr
1012		bl	__armv7_mmu_cache_flush
1013		mov	r0, #0
1014#ifdef CONFIG_MMU
1015		mcr	p15, 0, r0, c8, c7, 0	@ invalidate whole TLB
1016#endif
1017		mcr	p15, 0, r0, c7, c5, 6	@ invalidate BTC
1018		mcr	p15, 0, r0, c7, c10, 4	@ DSB
1019		mcr	p15, 0, r0, c7, c5, 4	@ ISB
1020		mov	pc, r12
1021
1022/*
1023 * Clean and flush the cache to maintain consistency.
1024 *
1025 * On exit,
1026 *  r1, r2, r3, r9, r10, r11, r12 corrupted
1027 * This routine must preserve:
1028 *  r4, r6, r7, r8
1029 */
1030		.align	5
1031cache_clean_flush:
1032		mov	r3, #16
1033		b	call_cache_fn
1034
1035__armv4_mpu_cache_flush:
1036		mov	r2, #1
1037		mov	r3, #0
1038		mcr	p15, 0, ip, c7, c6, 0	@ invalidate D cache
1039		mov	r1, #7 << 5		@ 8 segments
10401:		orr	r3, r1, #63 << 26	@ 64 entries
10412:		mcr	p15, 0, r3, c7, c14, 2	@ clean & invalidate D index
1042		subs	r3, r3, #1 << 26
1043		bcs	2b			@ entries 63 to 0
1044		subs 	r1, r1, #1 << 5
1045		bcs	1b			@ segments 7 to 0
1046
1047		teq	r2, #0
1048		mcrne	p15, 0, ip, c7, c5, 0	@ invalidate I cache
1049		mcr	p15, 0, ip, c7, c10, 4	@ drain WB
1050		mov	pc, lr
1051
1052__fa526_cache_flush:
1053		mov	r1, #0
1054		mcr	p15, 0, r1, c7, c14, 0	@ clean and invalidate D cache
1055		mcr	p15, 0, r1, c7, c5, 0	@ flush I cache
1056		mcr	p15, 0, r1, c7, c10, 4	@ drain WB
1057		mov	pc, lr
1058
1059__armv6_mmu_cache_flush:
1060		mov	r1, #0
1061		mcr	p15, 0, r1, c7, c14, 0	@ clean+invalidate D
1062		mcr	p15, 0, r1, c7, c5, 0	@ invalidate I+BTB
1063		mcr	p15, 0, r1, c7, c15, 0	@ clean+invalidate unified
1064		mcr	p15, 0, r1, c7, c10, 4	@ drain WB
1065		mov	pc, lr
1066
1067__armv7_mmu_cache_flush:
1068		mrc	p15, 0, r10, c0, c1, 5	@ read ID_MMFR1
1069		tst	r10, #0xf << 16		@ hierarchical cache (ARMv7)
1070		mov	r10, #0
1071		beq	hierarchical
1072		mcr	p15, 0, r10, c7, c14, 0	@ clean+invalidate D
1073		b	iflush
1074hierarchical:
1075		mcr	p15, 0, r10, c7, c10, 5	@ DMB
1076		stmfd	sp!, {r0-r7, r9-r11}
1077		mrc	p15, 1, r0, c0, c0, 1	@ read clidr
1078		ands	r3, r0, #0x7000000	@ extract loc from clidr
1079		mov	r3, r3, lsr #23		@ left align loc bit field
1080		beq	finished		@ if loc is 0, then no need to clean
1081		mov	r10, #0			@ start clean at cache level 0
1082loop1:
1083		add	r2, r10, r10, lsr #1	@ work out 3x current cache level
1084		mov	r1, r0, lsr r2		@ extract cache type bits from clidr
1085		and	r1, r1, #7		@ mask of the bits for current cache only
1086		cmp	r1, #2			@ see what cache we have at this level
1087		blt	skip			@ skip if no cache, or just i-cache
1088		mcr	p15, 2, r10, c0, c0, 0	@ select current cache level in cssr
1089		mcr	p15, 0, r10, c7, c5, 4	@ isb to sych the new cssr&csidr
1090		mrc	p15, 1, r1, c0, c0, 0	@ read the new csidr
1091		and	r2, r1, #7		@ extract the length of the cache lines
1092		add	r2, r2, #4		@ add 4 (line length offset)
1093		ldr	r4, =0x3ff
1094		ands	r4, r4, r1, lsr #3	@ find maximum number on the way size
1095		clz	r5, r4			@ find bit position of way size increment
1096		ldr	r7, =0x7fff
1097		ands	r7, r7, r1, lsr #13	@ extract max number of the index size
1098loop2:
1099		mov	r9, r4			@ create working copy of max way size
1100loop3:
1101 ARM(		orr	r11, r10, r9, lsl r5	) @ factor way and cache number into r11
1102 ARM(		orr	r11, r11, r7, lsl r2	) @ factor index number into r11
1103 THUMB(		lsl	r6, r9, r5		)
1104 THUMB(		orr	r11, r10, r6		) @ factor way and cache number into r11
1105 THUMB(		lsl	r6, r7, r2		)
1106 THUMB(		orr	r11, r11, r6		) @ factor index number into r11
1107		mcr	p15, 0, r11, c7, c14, 2	@ clean & invalidate by set/way
1108		subs	r9, r9, #1		@ decrement the way
1109		bge	loop3
1110		subs	r7, r7, #1		@ decrement the index
1111		bge	loop2
1112skip:
1113		add	r10, r10, #2		@ increment cache number
1114		cmp	r3, r10
1115		bgt	loop1
1116finished:
1117		ldmfd	sp!, {r0-r7, r9-r11}
1118		mov	r10, #0			@ swith back to cache level 0
1119		mcr	p15, 2, r10, c0, c0, 0	@ select current cache level in cssr
1120iflush:
1121		mcr	p15, 0, r10, c7, c10, 4	@ DSB
1122		mcr	p15, 0, r10, c7, c5, 0	@ invalidate I+BTB
1123		mcr	p15, 0, r10, c7, c10, 4	@ DSB
1124		mcr	p15, 0, r10, c7, c5, 4	@ ISB
1125		mov	pc, lr
1126
1127__armv5tej_mmu_cache_flush:
11281:		mrc	p15, 0, r15, c7, c14, 3	@ test,clean,invalidate D cache
1129		bne	1b
1130		mcr	p15, 0, r0, c7, c5, 0	@ flush I cache
1131		mcr	p15, 0, r0, c7, c10, 4	@ drain WB
1132		mov	pc, lr
1133
1134__armv4_mmu_cache_flush:
1135		mov	r2, #64*1024		@ default: 32K dcache size (*2)
1136		mov	r11, #32		@ default: 32 byte line size
1137		mrc	p15, 0, r3, c0, c0, 1	@ read cache type
1138		teq	r3, r9			@ cache ID register present?
1139		beq	no_cache_id
1140		mov	r1, r3, lsr #18
1141		and	r1, r1, #7
1142		mov	r2, #1024
1143		mov	r2, r2, lsl r1		@ base dcache size *2
1144		tst	r3, #1 << 14		@ test M bit
1145		addne	r2, r2, r2, lsr #1	@ +1/2 size if M == 1
1146		mov	r3, r3, lsr #12
1147		and	r3, r3, #3
1148		mov	r11, #8
1149		mov	r11, r11, lsl r3	@ cache line size in bytes
1150no_cache_id:
1151		mov	r1, pc
1152		bic	r1, r1, #63		@ align to longest cache line
1153		add	r2, r1, r2
11541:
1155 ARM(		ldr	r3, [r1], r11		) @ s/w flush D cache
1156 THUMB(		ldr     r3, [r1]		) @ s/w flush D cache
1157 THUMB(		add     r1, r1, r11		)
1158		teq	r1, r2
1159		bne	1b
1160
1161		mcr	p15, 0, r1, c7, c5, 0	@ flush I cache
1162		mcr	p15, 0, r1, c7, c6, 0	@ flush D cache
1163		mcr	p15, 0, r1, c7, c10, 4	@ drain WB
1164		mov	pc, lr
1165
1166__armv3_mmu_cache_flush:
1167__armv3_mpu_cache_flush:
1168		mov	r1, #0
1169		mcr	p15, 0, r1, c7, c0, 0	@ invalidate whole cache v3
1170		mov	pc, lr
1171
1172/*
1173 * Various debugging routines for printing hex characters and
1174 * memory, which again must be relocatable.
1175 */
1176#ifdef DEBUG
1177		.align	2
1178		.type	phexbuf,#object
1179phexbuf:	.space	12
1180		.size	phexbuf, . - phexbuf
1181
1182@ phex corrupts {r0, r1, r2, r3}
1183phex:		adr	r3, phexbuf
1184		mov	r2, #0
1185		strb	r2, [r3, r1]
11861:		subs	r1, r1, #1
1187		movmi	r0, r3
1188		bmi	puts
1189		and	r2, r0, #15
1190		mov	r0, r0, lsr #4
1191		cmp	r2, #10
1192		addge	r2, r2, #7
1193		add	r2, r2, #'0'
1194		strb	r2, [r3, r1]
1195		b	1b
1196
1197@ puts corrupts {r0, r1, r2, r3}
1198puts:		loadsp	r3, r1
11991:		ldrb	r2, [r0], #1
1200		teq	r2, #0
1201		moveq	pc, lr
12022:		writeb	r2, r3
1203		mov	r1, #0x00020000
12043:		subs	r1, r1, #1
1205		bne	3b
1206		teq	r2, #'\n'
1207		moveq	r2, #'\r'
1208		beq	2b
1209		teq	r0, #0
1210		bne	1b
1211		mov	pc, lr
1212@ putc corrupts {r0, r1, r2, r3}
1213putc:
1214		mov	r2, r0
1215		mov	r0, #0
1216		loadsp	r3, r1
1217		b	2b
1218
1219@ memdump corrupts {r0, r1, r2, r3, r10, r11, r12, lr}
1220memdump:	mov	r12, r0
1221		mov	r10, lr
1222		mov	r11, #0
12232:		mov	r0, r11, lsl #2
1224		add	r0, r0, r12
1225		mov	r1, #8
1226		bl	phex
1227		mov	r0, #':'
1228		bl	putc
12291:		mov	r0, #' '
1230		bl	putc
1231		ldr	r0, [r12, r11, lsl #2]
1232		mov	r1, #8
1233		bl	phex
1234		and	r0, r11, #7
1235		teq	r0, #3
1236		moveq	r0, #' '
1237		bleq	putc
1238		and	r0, r11, #7
1239		add	r11, r11, #1
1240		teq	r0, #7
1241		bne	1b
1242		mov	r0, #'\n'
1243		bl	putc
1244		cmp	r11, #64
1245		blt	2b
1246		mov	pc, r10
1247#endif
1248
1249		.ltorg
1250
1251#ifdef CONFIG_ARM_VIRT_EXT
1252.align 5
1253__hyp_reentry_vectors:
1254		W(b)	.			@ reset
1255		W(b)	.			@ undef
1256		W(b)	.			@ svc
1257		W(b)	.			@ pabort
1258		W(b)	.			@ dabort
1259		W(b)	__enter_kernel		@ hyp
1260		W(b)	.			@ irq
1261		W(b)	.			@ fiq
1262#endif /* CONFIG_ARM_VIRT_EXT */
1263
1264__enter_kernel:
1265		mov	r0, #0			@ must be 0
1266 ARM(		mov	pc, r4	)		@ call kernel
1267 THUMB(		bx	r4	)		@ entry point is always ARM
1268
1269reloc_code_end:
1270
1271		.align
1272		.section ".stack", "aw", %nobits
1273.L_user_stack:	.space	4096
1274.L_user_stack_end:
1275