xref: /rk3399_rockchip-uboot/arch/arm/cpu/pxa/start.S (revision 754ae3fbb76dc429ef932bbd04b432196efe45ff)
1/*
2 *  armboot - Startup Code for XScale
3 *
4 *  Copyright (C) 1998	Dan Malek <dmalek@jlc.net>
5 *  Copyright (C) 1999	Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se>
6 *  Copyright (C) 2000	Wolfgang Denk <wd@denx.de>
7 *  Copyright (C) 2001	Alex Zuepke <azu@sysgo.de>
8 *  Copyright (C) 2002	Kyle Harris <kharris@nexus-tech.net>
9 *  Copyright (C) 2003	Robert Schwebel <r.schwebel@pengutronix.de>
10 *  Copyright (C) 2003	Kai-Uwe Bloem <kai-uwe.bloem@auerswald.de>
11 *
12 * See file CREDITS for list of people who contributed to this
13 * project.
14 *
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License as
17 * published by the Free Software Foundation; either version 2 of
18 * the License, or (at your option) any later version.
19 *
20 * This program is distributed in the hope that it will be useful,
21 * but WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
23 * GNU General Public License for more details.
24 *
25 * You should have received a copy of the GNU General Public License
26 * along with this program; if not, write to the Free Software
27 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
28 * MA 02111-1307 USA
29 */
30
31#include <config.h>
32#include <version.h>
33#include <asm/arch/pxa-regs.h>
34#include <asm/arch/macro.h>
35
36/* takes care the CP15 update has taken place */
37.macro CPWAIT reg
38mrc  p15,0,\reg,c2,c0,0
39mov  \reg,\reg
40sub  pc,pc,#4
41.endm
42
43.globl _start
44_start: b	reset
45#ifdef CONFIG_PRELOADER
46	ldr	pc, _hang
47	ldr	pc, _hang
48	ldr	pc, _hang
49	ldr	pc, _hang
50	ldr	pc, _hang
51	ldr	pc, _hang
52	ldr	pc, _hang
53
54_hang:
55	.word	do_hang
56	.word	0x12345678
57	.word	0x12345678
58	.word	0x12345678
59	.word	0x12345678
60	.word	0x12345678
61	.word	0x12345678
62	.word	0x12345678	/* now 16*4=64 */
63#else
64	ldr	pc, _undefined_instruction
65	ldr	pc, _software_interrupt
66	ldr	pc, _prefetch_abort
67	ldr	pc, _data_abort
68	ldr	pc, _not_used
69	ldr	pc, _irq
70	ldr	pc, _fiq
71
72_undefined_instruction: .word undefined_instruction
73_software_interrupt:	.word software_interrupt
74_prefetch_abort:	.word prefetch_abort
75_data_abort:		.word data_abort
76_not_used:		.word not_used
77_irq:			.word irq
78_fiq:			.word fiq
79#endif	/* CONFIG_PRELOADER */
80
81	.balignl 16,0xdeadbeef
82
83
84/*
85 * Startup Code (reset vector)
86 *
87 * do important init only if we don't start from RAM!
88 * - relocate armboot to RAM
89 * - setup stack
90 * - jump to second stage
91 */
92
93.globl _TEXT_BASE
94_TEXT_BASE:
95	.word	CONFIG_SYS_TEXT_BASE
96
97.globl _armboot_start
98_armboot_start:
99	.word _start
100
101/*
102 * These are defined in the board-specific linker script.
103 */
104.globl _bss_start
105_bss_start:
106	.word __bss_start
107
108.globl _bss_end
109_bss_end:
110	.word _end
111
112#ifdef CONFIG_USE_IRQ
113/* IRQ stack memory (calculated at run-time) */
114.globl IRQ_STACK_START
115IRQ_STACK_START:
116	.word	0x0badc0de
117
118/* IRQ stack memory (calculated at run-time) */
119.globl FIQ_STACK_START
120FIQ_STACK_START:
121	.word 0x0badc0de
122#endif /* CONFIG_USE_IRQ */
123
124#ifndef CONFIG_PRELOADER
125/* IRQ stack memory (calculated at run-time) + 8 bytes */
126.globl IRQ_STACK_START_IN
127IRQ_STACK_START_IN:
128	.word	0x0badc0de
129
130.globl _datarel_start
131_datarel_start:
132	.word __datarel_start
133
134.globl _datarelrolocal_start
135_datarelrolocal_start:
136	.word __datarelrolocal_start
137
138.globl _datarellocal_start
139_datarellocal_start:
140	.word __datarellocal_start
141
142.globl _datarelro_start
143_datarelro_start:
144	.word __datarelro_start
145
146.globl _got_start
147_got_start:
148	.word __got_start
149
150.globl _got_end
151_got_end:
152	.word __got_end
153
154/*
155 * the actual reset code
156 */
157
158reset:
159	/*
160	 * set the cpu to SVC32 mode
161	 */
162	mrs	r0,cpsr
163	bic	r0,r0,#0x1f
164	orr	r0,r0,#0xd3
165	msr	cpsr,r0
166
167	/*
168	 * Enable MMU to use DCache as DRAM
169	 */
170	/* Domain access -- enable for all CPs */
171	ldr	r0, =0x0000ffff
172	mcr	p15, 0, r0, c3, c0, 0
173
174	/* Point TTBR to MMU table */
175	ldr	r0, =mmu_table
176	adr	r2, _start
177	orr	r0, r2
178	mcr	p15, 0, r0, c2, c0, 0
179
180/* !!! Hereby, check if the code is running from SRAM !!! */
181/* If the code is running from SRAM, alias SRAM to 0x0 to simulate NOR. The code
182 * is linked to 0x0 too, so this makes things easier. */
183	cmp	r2, #0x5c000000
184
185	ldreq	r1, [r0]
186	orreq	r1, r2
187	streq	r1, [r0]
188
189	/* Kick in MMU, ICache, DCache, BTB */
190	mrc	p15, 0, r0, c1, c0, 0
191	bic	r0, #0x1b00
192	bic	r0, #0x0087
193	orr	r0, #0x1800
194	orr	r0, #0x0005
195	mcr	p15, 0, r0, c1, c0, 0
196	CPWAIT	r0
197
198	/* Unlock Icache, Dcache */
199	mcr	p15, 0, r0, c9, c1, 1
200	mcr	p15, 0, r0, c9, c2, 1
201
202	/* Flush Icache, Dcache, BTB */
203	mcr	p15, 0, r0, c7, c7, 0
204
205	/* Unlock I-TLB, D-TLB */
206	mcr	p15, 0, r0, c10, c4, 1
207	mcr	p15, 0, r0, c10, c8, 1
208
209	/* Flush TLB */
210	mcr	p15, 0, r0, c8, c7, 0
211	/* Allocate 4096 bytes of Dcache as RAM */
212
213	/* Drain pending loads and stores */
214	mcr	p15, 0, r0, c7, c10, 4
215
216	mov	r4, #0x00
217	mov	r5, #0x00
218	mov	r2, #0x01
219	mcr	p15, 0, r0, c9, c2, 0
220	CPWAIT	r0
221
222	/* 128 lines reserved (128 x 32bytes = 4096 bytes total) */
223	mov	r0, #128
224	mov	r1, #0xa0000000
225alloc:
226	mcr	p15, 0, r1, c7, c2, 5
227	/* Drain pending loads and stores */
228	mcr	p15, 0, r0, c7, c10, 4
229	strd	r4, [r1], #8
230	strd	r4, [r1], #8
231	strd	r4, [r1], #8
232	strd	r4, [r1], #8
233	subs	r0, #0x01
234	bne	alloc
235	/* Drain pending loads and stores */
236	mcr	p15, 0, r0, c7, c10, 4
237	mov	r2, #0x00
238	mcr	p15, 0, r2, c9, c2, 0
239	CPWAIT	r0
240
241	/* Jump to 0x0 ( + offset) if running from SRAM */
242	adr	r0, zerojmp
243	bic	r0, #0x5c000000
244	mov	pc, r0
245zerojmp:
246
247/* Set stackpointer in internal RAM to call board_init_f */
248call_board_init_f:
249	ldr	sp, =(CONFIG_SYS_INIT_SP_ADDR)
250	ldr	r0,=0x00000000
251	bl	board_init_f
252
253/*------------------------------------------------------------------------------*/
254
255/*
256 * void relocate_code (addr_sp, gd, addr_moni)
257 *
258 * This "function" does not return, instead it continues in RAM
259 * after relocating the monitor code.
260 *
261 */
262	.globl	relocate_code
263relocate_code:
264	mov	r4, r0	/* save addr_sp */
265	mov	r5, r1	/* save addr of gd */
266	mov	r6, r2	/* save addr of destination */
267	mov	r7, r2	/* save addr of destination */
268
269	/* Set up the stack						    */
270stack_setup:
271	mov	sp, r4
272
273	adr	r0, _start
274	ldr	r2, _TEXT_BASE
275	ldr	r3, _bss_start
276	sub	r2, r3, r2		/* r2 <- size of armboot	    */
277	add	r2, r0, r2		/* r2 <- source end address	    */
278	cmp	r0, r6
279	beq	clear_bss
280
281#ifndef CONFIG_SKIP_RELOCATE_UBOOT
282	stmfd sp!, {r0-r12}
283copy_loop:
284	ldmia	r0!, {r3-r5, r7-r11}	/* copy from source address [r0]    */
285	stmia	r6!, {r3-r5, r7-r11}	/* copy to   target address [r1]    */
286	cmp	r0, r2			/* until source end address [r2]    */
287	blo	copy_loop
288	ldmfd sp!, {r0-r12}
289
290#ifndef CONFIG_PRELOADER
291	/* fix got entries */
292	ldr	r1, _TEXT_BASE		/* Text base */
293	mov	r0, r7			/* reloc addr */
294	ldr	r2, _got_start		/* addr in Flash */
295	ldr	r3, _got_end		/* addr in Flash */
296	sub	r3, r3, r1
297	add	r3, r3, r0
298	sub	r2, r2, r1
299	add	r2, r2, r0
300
301fixloop:
302	ldr	r4, [r2]
303	sub	r4, r4, r1
304	add	r4, r4, r0
305	str	r4, [r2]
306	add	r2, r2, #4
307	cmp	r2, r3
308	bne	fixloop
309#endif
310#endif	/* #ifndef CONFIG_SKIP_RELOCATE_UBOOT */
311
312clear_bss:
313#ifndef CONFIG_PRELOADER
314	ldr	r0, _bss_start
315	ldr	r1, _bss_end
316	ldr	r3, _TEXT_BASE		/* Text base */
317	mov	r4, r7			/* reloc addr */
318	sub	r0, r0, r3
319	add	r0, r0, r4
320	sub	r1, r1, r3
321	add	r1, r1, r4
322	mov	r2, #0x00000000		/* clear			    */
323
324clbss_l:str	r2, [r0]		/* clear loop...		    */
325	add	r0, r0, #4
326	cmp	r0, r1
327	bne	clbss_l
328#endif
329
330/*
331 * We are done. Do not return, instead branch to second part of board
332 * initialization, now running from RAM.
333 */
334#ifdef CONFIG_ONENAND_IPL
335	ldr     pc, _start_oneboot
336
337_start_oneboot: .word start_oneboot
338#else
339	ldr	r0, _TEXT_BASE
340	ldr	r2, _board_init_r
341	sub	r2, r2, r0
342	add	r2, r2, r7	/* position from board_init_r in RAM */
343	/* setup parameters for board_init_r */
344	mov	r0, r5		/* gd_t */
345	mov	r1, r7		/* dest_addr */
346	/* jump to it ... */
347	mov	lr, r2
348	mov	pc, lr
349
350_board_init_r: .word board_init_r
351#endif
352
353#else /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
354
355/****************************************************************************/
356/*									    */
357/* the actual reset code for OneNAND IPL				    */
358/*									    */
359/****************************************************************************/
360
361#ifndef	CONFIG_PXA27X
362#error OneNAND IPL is not supported on PXA25x and 26x due to lack of SRAM
363#endif
364
365reset:
366	/* Set CPU to SVC32 mode */
367	mrs	r0,cpsr
368	bic	r0,r0,#0x1f
369	orr	r0,r0,#0x13
370	msr	cpsr,r0
371
372	/* Point stack at the end of SRAM and leave 32 words for abort-stack */
373	ldr	sp, =0x5c03ff80
374
375	/* Start OneNAND IPL */
376	ldr	pc, =start_oneboot
377
378#endif /* #if !defined(CONFIG_ONENAND_IPL) */
379
380#ifndef CONFIG_PRELOADER
381/****************************************************************************/
382/*									    */
383/* Interrupt handling							    */
384/*									    */
385/****************************************************************************/
386
387/* IRQ stack frame							    */
388
389#define S_FRAME_SIZE	72
390
391#define S_OLD_R0	68
392#define S_PSR		64
393#define S_PC		60
394#define S_LR		56
395#define S_SP		52
396
397#define S_IP		48
398#define S_FP		44
399#define S_R10		40
400#define S_R9		36
401#define S_R8		32
402#define S_R7		28
403#define S_R6		24
404#define S_R5		20
405#define S_R4		16
406#define S_R3		12
407#define S_R2		8
408#define S_R1		4
409#define S_R0		0
410
411#define MODE_SVC 0x13
412
413	/* use bad_save_user_regs for abort/prefetch/undef/swi ...	    */
414
415	.macro	bad_save_user_regs
416	sub	sp, sp, #S_FRAME_SIZE
417	stmia	sp, {r0 - r12}			/* Calling r0-r12	    */
418	add	r8, sp, #S_PC
419
420#if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
421	ldr	r2, _armboot_start
422	sub	r2, r2, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
423	sub	r2, r2, #(CONFIG_SYS_GBL_DATA_SIZE+8)	@ set base 2 words into abort stack
424#else
425	ldr	r2, IRQ_STACK_START_IN
426#endif
427	ldmia	r2, {r2 - r4}			/* get pc, cpsr, old_r0	    */
428	add	r0, sp, #S_FRAME_SIZE		/* restore sp_SVC	    */
429
430	add	r5, sp, #S_SP
431	mov	r1, lr
432	stmia	r5, {r0 - r4}			/* save sp_SVC, lr_SVC, pc, cpsr, old_r */
433	mov	r0, sp
434	.endm
435
436
437	/* use irq_save_user_regs / irq_restore_user_regs for		     */
438	/* IRQ/FIQ handling						     */
439
440	.macro	irq_save_user_regs
441	sub	sp, sp, #S_FRAME_SIZE
442	stmia	sp, {r0 - r12}			/* Calling r0-r12	     */
443	add	r8, sp, #S_PC
444	stmdb	r8, {sp, lr}^			/* Calling SP, LR	     */
445	str	lr, [r8, #0]			/* Save calling PC	     */
446	mrs	r6, spsr
447	str	r6, [r8, #4]			/* Save CPSR		     */
448	str	r0, [r8, #8]			/* Save OLD_R0		     */
449	mov	r0, sp
450	.endm
451
452	.macro	irq_restore_user_regs
453	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
454	mov	r0, r0
455	ldr	lr, [sp, #S_PC]			@ Get PC
456	add	sp, sp, #S_FRAME_SIZE
457	subs	pc, lr, #4			@ return & move spsr_svc into cpsr
458	.endm
459
460	.macro get_bad_stack
461#if defined(CONFIG_SYS_ARM_WITHOUT_RELOC)
462	ldr	r13, _armboot_start		@ setup our mode stack
463	sub	r13, r13, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN)
464	sub	r13, r13, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ reserved a couple spots in abort stack
465#else
466	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
467#endif
468
469	str	lr, [r13]			@ save caller lr / spsr
470	mrs	lr, spsr
471	str	lr, [r13, #4]
472
473	mov	r13, #MODE_SVC			@ prepare SVC-Mode
474	msr	spsr_c, r13
475	mov	lr, pc
476	movs	pc, lr
477	.endm
478
479	.macro get_irq_stack			@ setup IRQ stack
480	ldr	sp, IRQ_STACK_START
481	.endm
482
483	.macro get_fiq_stack			@ setup FIQ stack
484	ldr	sp, FIQ_STACK_START
485	.endm
486#endif	/* CONFIG_PRELOADER */
487
488
489/****************************************************************************/
490/*									    */
491/* exception handlers							    */
492/*									    */
493/****************************************************************************/
494
495#ifdef CONFIG_PRELOADER
496	.align	5
497do_hang:
498	ldr	sp, _TEXT_BASE			/* use 32 words abort stack */
499	bl	hang				/* hang and never return */
500#else	/* !CONFIG_PRELOADER */
501	.align	5
502undefined_instruction:
503	get_bad_stack
504	bad_save_user_regs
505	bl	do_undefined_instruction
506
507	.align	5
508software_interrupt:
509	get_bad_stack
510	bad_save_user_regs
511	bl	do_software_interrupt
512
513	.align	5
514prefetch_abort:
515	get_bad_stack
516	bad_save_user_regs
517	bl	do_prefetch_abort
518
519	.align	5
520data_abort:
521	get_bad_stack
522	bad_save_user_regs
523	bl	do_data_abort
524
525	.align	5
526not_used:
527	get_bad_stack
528	bad_save_user_regs
529	bl	do_not_used
530
531#ifdef CONFIG_USE_IRQ
532
533	.align	5
534irq:
535	get_irq_stack
536	irq_save_user_regs
537	bl	do_irq
538	irq_restore_user_regs
539
540	.align	5
541fiq:
542	get_fiq_stack
543	irq_save_user_regs		/* someone ought to write a more    */
544	bl	do_fiq			/* effiction fiq_save_user_regs	    */
545	irq_restore_user_regs
546
547#else /* !CONFIG_USE_IRQ */
548
549	.align	5
550irq:
551	get_bad_stack
552	bad_save_user_regs
553	bl	do_irq
554
555	.align	5
556fiq:
557	get_bad_stack
558	bad_save_user_regs
559	bl	do_fiq
560#endif	/* CONFIG_PRELOADER */
561#endif /* CONFIG_USE_IRQ */
562
563/****************************************************************************/
564/*									    */
565/* Reset function: the PXA250 doesn't have a reset function, so we have to  */
566/* perform a watchdog timeout for a soft reset.				    */
567/*									    */
568/****************************************************************************/
569/* Operating System Timer */
570OSTIMER_BASE:	.word	0x40a00000
571#define OSMR3	0x0C
572#define OSCR	0x10
573#define OWER	0x18
574#define OIER	0x1C
575
576	.align	5
577.globl reset_cpu
578
579	/* FIXME: this code is PXA250 specific. How is this handled on	    */
580	/*	  other XScale processors?				    */
581
582reset_cpu:
583
584	/* We set OWE:WME (watchdog enable) and wait until timeout happens  */
585
586	ldr	r0, OSTIMER_BASE
587	ldr	r1, [r0, #OWER]
588	orr	r1, r1, #0x0001			/* bit0: WME		    */
589	str	r1, [r0, #OWER]
590
591	/* OS timer does only wrap every 1165 seconds, so we have to set    */
592	/* the match register as well.					    */
593
594	ldr	r1, [r0, #OSCR]			/* read OS timer	    */
595	add	r1, r1, #0x800			/* let OSMR3 match after    */
596	add	r1, r1, #0x800			/* 4096*(1/3.6864MHz)=1ms   */
597	str	r1, [r0, #OSMR3]
598
599reset_endless:
600
601	b	reset_endless
602
603#ifndef CONFIG_PRELOADER
604.section .mmudata, "a"
605	.align	14
606	.globl	mmu_table
607mmu_table:
608	/* 0x00000000 - 0xa0000000 : 1:1, uncached mapping */
609	.set	__base, 0
610	.rept	0xa00
611	.word	(__base << 20) | 0xc12
612	.set	__base, __base + 1
613	.endr
614
615	/* 0xa0000000 - 0xa0100000 : 1:1, cached mapping */
616	.word	(0xa00 << 20) | 0x1c1e
617
618	.set	__base, 0xa01
619	.rept	0x1000 - 0xa01
620	.word	(__base << 20) | 0xc12
621	.set	__base, __base + 1
622	.endr
623#endif
624