xref: /openbmc/u-boot/arch/arm/cpu/pxa/start.S (revision 5c8d14df)
1/*
2 *  armboot - Startup Code for XScale CPU-core
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) 2001	Marius Groger <mag@sysgo.de>
9 *  Copyright (C) 2002	Alex Zupke <azu@sysgo.de>
10 *  Copyright (C) 2002	Gary Jennejohn <garyj@denx.de>
11 *  Copyright (C) 2002	Kyle Harris <kharris@nexus-tech.net>
12 *  Copyright (C) 2003	Kai-Uwe Bloem <kai-uwe.bloem@auerswald.de>
13 *  Copyright (C) 2003	Kshitij <kshitij@ti.com>
14 *  Copyright (C) 2003	Richard Woodruff <r-woodruff2@ti.com>
15 *  Copyright (C) 2003	Robert Schwebel <r.schwebel@pengutronix.de>
16 *  Copyright (C) 2004	Texas Instruments <r-woodruff2@ti.com>
17 *  Copyright (C) 2010	Marek Vasut <marek.vasut@gmail.com>
18 *
19 * See file CREDITS for list of people who contributed to this
20 * project.
21 *
22 * This program is free software; you can redistribute it and/or
23 * modify it under the terms of the GNU General Public License as
24 * published by the Free Software Foundation; either version 2 of
25 * the License, or (at your option) any later version.
26 *
27 * This program is distributed in the hope that it will be useful,
28 * but WITHOUT ANY WARRANTY; without even the implied warranty of
29 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
30 * GNU General Public License for more details.
31 *
32 * You should have received a copy of the GNU General Public License
33 * along with this program; if not, write to the Free Software
34 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
35 * MA 02111-1307 USA
36 */
37
38#include <asm-offsets.h>
39#include <config.h>
40#include <version.h>
41
42#ifdef CONFIG_CPU_PXA25X
43#if ((CONFIG_SYS_INIT_SP_ADDR) != 0xfffff800)
44#error "Init SP address must be set to 0xfffff800 for PXA250"
45#endif
46#endif
47
48.globl _start
49_start: b	reset
50#ifdef CONFIG_SPL_BUILD
51	ldr	pc, _hang
52	ldr	pc, _hang
53	ldr	pc, _hang
54	ldr	pc, _hang
55	ldr	pc, _hang
56	ldr	pc, _hang
57	ldr	pc, _hang
58
59_hang:
60	.word	do_hang
61	.word	0x12345678
62	.word	0x12345678
63	.word	0x12345678
64	.word	0x12345678
65	.word	0x12345678
66	.word	0x12345678
67	.word	0x12345678	/* now 16*4=64 */
68#else
69	ldr	pc, _undefined_instruction
70	ldr	pc, _software_interrupt
71	ldr	pc, _prefetch_abort
72	ldr	pc, _data_abort
73	ldr	pc, _not_used
74	ldr	pc, _irq
75	ldr	pc, _fiq
76
77_undefined_instruction: .word undefined_instruction
78_software_interrupt:	.word software_interrupt
79_prefetch_abort:	.word prefetch_abort
80_data_abort:		.word data_abort
81_not_used:		.word not_used
82_irq:			.word irq
83_fiq:			.word fiq
84_pad:			.word 0x12345678 /* now 16*4=64 */
85#endif	/* CONFIG_SPL_BUILD */
86.global _end_vect
87_end_vect:
88
89	.balignl 16,0xdeadbeef
90/*
91 *************************************************************************
92 *
93 * Startup Code (reset vector)
94 *
95 * do important init only if we don't start from memory!
96 * setup Memory and board specific bits prior to relocation.
97 * relocate armboot to ram
98 * setup stack
99 *
100 *************************************************************************
101 */
102
103.globl _TEXT_BASE
104_TEXT_BASE:
105#ifdef	CONFIG_SPL_BUILD
106	.word	CONFIG_SPL_TEXT_BASE
107#else
108	.word	CONFIG_SYS_TEXT_BASE
109#endif
110
111/*
112 * These are defined in the board-specific linker script.
113 * Subtracting _start from them lets the linker put their
114 * relative position in the executable instead of leaving
115 * them null.
116 */
117.globl _bss_start_ofs
118_bss_start_ofs:
119	.word __bss_start - _start
120
121.globl _bss_end_ofs
122_bss_end_ofs:
123	.word __bss_end__ - _start
124
125.globl _end_ofs
126_end_ofs:
127	.word _end - _start
128
129#ifdef CONFIG_USE_IRQ
130/* IRQ stack memory (calculated at run-time) */
131.globl IRQ_STACK_START
132IRQ_STACK_START:
133	.word	0x0badc0de
134
135/* IRQ stack memory (calculated at run-time) */
136.globl FIQ_STACK_START
137FIQ_STACK_START:
138	.word 0x0badc0de
139#endif
140
141/* IRQ stack memory (calculated at run-time) + 8 bytes */
142.globl IRQ_STACK_START_IN
143IRQ_STACK_START_IN:
144	.word	0x0badc0de
145
146/*
147 * the actual reset code
148 */
149
150reset:
151	/*
152	 * set the cpu to SVC32 mode
153	 */
154	mrs	r0,cpsr
155	bic	r0,r0,#0x1f
156	orr	r0,r0,#0xd3
157	msr	cpsr,r0
158
159#ifndef CONFIG_SKIP_LOWLEVEL_INIT
160	bl  cpu_init_crit
161#endif
162
163#ifdef	CONFIG_CPU_PXA25X
164	bl	lock_cache_for_stack
165#endif
166
167/* Set stackpointer in internal RAM to call board_init_f */
168call_board_init_f:
169	ldr	sp, =(CONFIG_SYS_INIT_SP_ADDR)
170	bic	sp, sp, #7 /* 8-byte alignment for ABI compliance */
171	ldr	r0, =0x00000000
172	bl	board_init_f
173
174/*------------------------------------------------------------------------------*/
175#ifndef CONFIG_SPL_BUILD
176/*
177 * void relocate_code (addr_sp, gd, addr_moni)
178 *
179 * This "function" does not return, instead it continues in RAM
180 * after relocating the monitor code.
181 *
182 */
183	.globl	relocate_code
184relocate_code:
185	mov	r4, r0	/* save addr_sp */
186	mov	r5, r1	/* save addr of gd */
187	mov	r6, r2	/* save addr of destination */
188
189	/* Set up the stack						    */
190stack_setup:
191	mov	sp, r4
192
193/* Disable the Dcache RAM lock for stack now */
194#ifdef	CONFIG_CPU_PXA25X
195	bl	cpu_init_crit
196#endif
197
198	adr	r0, _start
199	cmp	r0, r6
200	beq	clear_bss		/* skip relocation */
201	mov	r1, r6			/* r1 <- scratch for copy_loop */
202	ldr	r3, _bss_start_ofs
203	add	r2, r0, r3		/* r2 <- source end address	    */
204
205copy_loop:
206	ldmia	r0!, {r9-r10}		/* copy from source address [r0]    */
207	stmia	r1!, {r9-r10}		/* copy to   target address [r1]    */
208	cmp	r0, r2			/* until source end address [r2]    */
209	blo	copy_loop
210
211#ifndef CONFIG_SPL_BUILD
212	/*
213	 * fix .rel.dyn relocations
214	 */
215	ldr	r0, _TEXT_BASE		/* r0 <- Text base */
216	sub	r9, r6, r0		/* r9 <- relocation offset */
217	ldr	r10, _dynsym_start_ofs	/* r10 <- sym table ofs */
218	add	r10, r10, r0		/* r10 <- sym table in FLASH */
219	ldr	r2, _rel_dyn_start_ofs	/* r2 <- rel dyn start ofs */
220	add	r2, r2, r0		/* r2 <- rel dyn start in FLASH */
221	ldr	r3, _rel_dyn_end_ofs	/* r3 <- rel dyn end ofs */
222	add	r3, r3, r0		/* r3 <- rel dyn end in FLASH */
223fixloop:
224	ldr	r0, [r2]		/* r0 <- location to fix up, IN FLASH! */
225	add	r0, r0, r9		/* r0 <- location to fix up in RAM */
226	ldr	r1, [r2, #4]
227	and	r7, r1, #0xff
228	cmp	r7, #23			/* relative fixup? */
229	beq	fixrel
230	cmp	r7, #2			/* absolute fixup? */
231	beq	fixabs
232	/* ignore unknown type of fixup */
233	b	fixnext
234fixabs:
235	/* absolute fix: set location to (offset) symbol value */
236	mov	r1, r1, LSR #4		/* r1 <- symbol index in .dynsym */
237	add	r1, r10, r1		/* r1 <- address of symbol in table */
238	ldr	r1, [r1, #4]		/* r1 <- symbol value */
239	add	r1, r1, r9		/* r1 <- relocated sym addr */
240	b	fixnext
241fixrel:
242	/* relative fix: increase location by offset */
243	ldr	r1, [r0]
244	add	r1, r1, r9
245fixnext:
246	str	r1, [r0]
247	add	r2, r2, #8		/* each rel.dyn entry is 8 bytes */
248	cmp	r2, r3
249	blo	fixloop
250#endif
251
252clear_bss:
253#ifndef CONFIG_SPL_BUILD
254	ldr	r0, _bss_start_ofs
255	ldr	r1, _bss_end_ofs
256	mov	r4, r6			/* reloc addr */
257	add	r0, r0, r4
258	add	r1, r1, r4
259	mov	r2, #0x00000000		/* clear			    */
260
261clbss_l:cmp	r0, r1			/* clear loop... */
262	bhs	clbss_e			/* if reached end of bss, exit */
263	str	r2, [r0]
264	add	r0, r0, #4
265	b	clbss_l
266clbss_e:
267#endif	/* #ifndef CONFIG_SPL_BUILD */
268
269/*
270 * We are done. Do not return, instead branch to second part of board
271 * initialization, now running from RAM.
272 */
273#ifdef CONFIG_ONENAND_SPL
274	ldr     r0, _onenand_boot_ofs
275	mov	pc, r0
276
277_onenand_boot_ofs:
278	.word onenand_boot
279#else
280jump_2_ram:
281	ldr	r0, _board_init_r_ofs
282	ldr     r1, _TEXT_BASE
283	add	lr, r0, r1
284	add	lr, lr, r9
285	/* setup parameters for board_init_r */
286	mov	r0, r5		/* gd_t */
287	mov	r1, r6		/* dest_addr */
288	/* jump to it ... */
289	mov	pc, lr
290
291_board_init_r_ofs:
292	.word board_init_r - _start
293#endif
294
295_rel_dyn_start_ofs:
296	.word __rel_dyn_start - _start
297_rel_dyn_end_ofs:
298	.word __rel_dyn_end - _start
299_dynsym_start_ofs:
300	.word __dynsym_start - _start
301#endif
302/*
303 *************************************************************************
304 *
305 * CPU_init_critical registers
306 *
307 * setup important registers
308 * setup memory timing
309 *
310 *************************************************************************
311 */
312#if !defined(CONFIG_SKIP_LOWLEVEL_INIT) || defined(CONFIG_CPU_PXA25X)
313cpu_init_crit:
314	/*
315	 * flush v4 I/D caches
316	 */
317	mov	r0, #0
318	mcr	p15, 0, r0, c7, c7, 0	/* Invalidate I+D+BTB caches */
319	mcr	p15, 0, r0, c8, c7, 0	/* Invalidate Unified TLB */
320
321	/*
322	 * disable MMU stuff and caches
323	 */
324	mrc	p15, 0, r0, c1, c0, 0
325	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
326	bic	r0, r0, #0x00000087	@ clear bits 7, 2:0 (B--- -CAM)
327	orr	r0, r0, #0x00000002	@ set bit 2 (A) Align
328	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-Cache
329	mcr	p15, 0, r0, c1, c0, 0
330
331	mov	pc, lr		/* back to my caller */
332#endif /* !CONFIG_SKIP_LOWLEVEL_INIT || CONFIG_CPU_PXA25X */
333
334#ifndef CONFIG_SPL_BUILD
335/*
336 *************************************************************************
337 *
338 * Interrupt handling
339 *
340 *************************************************************************
341 */
342@
343@ IRQ stack frame.
344@
345#define S_FRAME_SIZE	72
346
347#define S_OLD_R0	68
348#define S_PSR		64
349#define S_PC		60
350#define S_LR		56
351#define S_SP		52
352
353#define S_IP		48
354#define S_FP		44
355#define S_R10		40
356#define S_R9		36
357#define S_R8		32
358#define S_R7		28
359#define S_R6		24
360#define S_R5		20
361#define S_R4		16
362#define S_R3		12
363#define S_R2		8
364#define S_R1		4
365#define S_R0		0
366
367#define MODE_SVC 0x13
368#define I_BIT	 0x80
369
370/*
371 * use bad_save_user_regs for abort/prefetch/undef/swi ...
372 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
373 */
374
375	.macro	bad_save_user_regs
376	sub	sp, sp, #S_FRAME_SIZE		@ carve out a frame on current user stack
377	stmia	sp, {r0 - r12}			@ Save user registers (now in svc mode) r0-r12
378
379	ldr	r2, IRQ_STACK_START_IN		@ set base 2 words into abort stack
380	ldmia	r2, {r2 - r3}			@ get values for "aborted" pc and cpsr (into parm regs)
381	add	r0, sp, #S_FRAME_SIZE		@ grab pointer to old stack
382
383	add	r5, sp, #S_SP
384	mov	r1, lr
385	stmia	r5, {r0 - r3}			@ save sp_SVC, lr_SVC, pc, cpsr
386	mov	r0, sp				@ save current stack into r0 (param register)
387	.endm
388
389	.macro	irq_save_user_regs
390	sub	sp, sp, #S_FRAME_SIZE
391	stmia	sp, {r0 - r12}			@ Calling r0-r12
392	add	r8, sp, #S_PC			@ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
393	stmdb	r8, {sp, lr}^			@ Calling SP, LR
394	str	lr, [r8, #0]			@ Save calling PC
395	mrs	r6, spsr
396	str	r6, [r8, #4]			@ Save CPSR
397	str	r0, [r8, #8]			@ Save OLD_R0
398	mov	r0, sp
399	.endm
400
401	.macro	irq_restore_user_regs
402	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
403	mov	r0, r0
404	ldr	lr, [sp, #S_PC]			@ Get PC
405	add	sp, sp, #S_FRAME_SIZE
406	subs	pc, lr, #4			@ return & move spsr_svc into cpsr
407	.endm
408
409	.macro get_bad_stack
410	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack (enter in banked mode)
411
412	str	lr, [r13]			@ save caller lr in position 0 of saved stack
413	mrs	lr, spsr			@ get the spsr
414	str	lr, [r13, #4]			@ save spsr in position 1 of saved stack
415
416	mov	r13, #MODE_SVC			@ prepare SVC-Mode
417	@ msr	spsr_c, r13
418	msr	spsr, r13			@ switch modes, make sure moves will execute
419	mov	lr, pc				@ capture return pc
420	movs	pc, lr				@ jump to next instruction & switch modes.
421	.endm
422
423	.macro get_bad_stack_swi
424	sub	r13, r13, #4			@ space on current stack for scratch reg.
425	str	r0, [r13]			@ save R0's value.
426	ldr	r0, IRQ_STACK_START_IN		@ get data regions start
427	str	lr, [r0]			@ save caller lr in position 0 of saved stack
428	mrs	r0, spsr			@ get the spsr
429	str	lr, [r0, #4]			@ save spsr in position 1 of saved stack
430	ldr	r0, [r13]			@ restore r0
431	add	r13, r13, #4			@ pop stack entry
432	.endm
433
434	.macro get_irq_stack			@ setup IRQ stack
435	ldr	sp, IRQ_STACK_START
436	.endm
437
438	.macro get_fiq_stack			@ setup FIQ stack
439	ldr	sp, FIQ_STACK_START
440	.endm
441#endif	/* CONFIG_SPL_BUILD */
442
443/*
444 * exception handlers
445 */
446#ifdef CONFIG_SPL_BUILD
447	.align	5
448do_hang:
449	ldr	sp, _TEXT_BASE			/* use 32 words about stack */
450	bl	hang				/* hang and never return */
451#else	/* !CONFIG_SPL_BUILD */
452	.align	5
453undefined_instruction:
454	get_bad_stack
455	bad_save_user_regs
456	bl	do_undefined_instruction
457
458	.align	5
459software_interrupt:
460	get_bad_stack_swi
461	bad_save_user_regs
462	bl	do_software_interrupt
463
464	.align	5
465prefetch_abort:
466	get_bad_stack
467	bad_save_user_regs
468	bl	do_prefetch_abort
469
470	.align	5
471data_abort:
472	get_bad_stack
473	bad_save_user_regs
474	bl	do_data_abort
475
476	.align	5
477not_used:
478	get_bad_stack
479	bad_save_user_regs
480	bl	do_not_used
481
482#ifdef CONFIG_USE_IRQ
483
484	.align	5
485irq:
486	get_irq_stack
487	irq_save_user_regs
488	bl	do_irq
489	irq_restore_user_regs
490
491	.align	5
492fiq:
493	get_fiq_stack
494	/* someone ought to write a more effiction fiq_save_user_regs */
495	irq_save_user_regs
496	bl	do_fiq
497	irq_restore_user_regs
498
499#else
500
501	.align	5
502irq:
503	get_bad_stack
504	bad_save_user_regs
505	bl	do_irq
506
507	.align	5
508fiq:
509	get_bad_stack
510	bad_save_user_regs
511	bl	do_fiq
512
513#endif
514	.align 5
515#endif	/* CONFIG_SPL_BUILD */
516
517
518/*
519 * Enable MMU to use DCache as DRAM.
520 *
521 * This is useful on PXA25x and PXA26x in early bootstages, where there is no
522 * other possible memory available to hold stack.
523 */
524#ifdef CONFIG_CPU_PXA25X
525.macro CPWAIT reg
526	mrc	p15, 0, \reg, c2, c0, 0
527	mov	\reg, \reg
528	sub	pc, pc, #4
529.endm
530lock_cache_for_stack:
531	/* Domain access -- enable for all CPs */
532	ldr	r0, =0x0000ffff
533	mcr	p15, 0, r0, c3, c0, 0
534
535	/* Point TTBR to MMU table */
536	ldr	r0, =mmutable
537	mcr	p15, 0, r0, c2, c0, 0
538
539	/* Kick in MMU, ICache, DCache, BTB */
540	mrc	p15, 0, r0, c1, c0, 0
541	bic	r0, #0x1b00
542	bic	r0, #0x0087
543	orr	r0, #0x1800
544	orr	r0, #0x0005
545	mcr	p15, 0, r0, c1, c0, 0
546	CPWAIT	r0
547
548	/* Unlock Icache, Dcache */
549	mcr	p15, 0, r0, c9, c1, 1
550	mcr	p15, 0, r0, c9, c2, 1
551
552	/* Flush Icache, Dcache, BTB */
553	mcr	p15, 0, r0, c7, c7, 0
554
555	/* Unlock I-TLB, D-TLB */
556	mcr	p15, 0, r0, c10, c4, 1
557	mcr	p15, 0, r0, c10, c8, 1
558
559	/* Flush TLB */
560	mcr	p15, 0, r0, c8, c7, 0
561
562	/* Allocate 4096 bytes of Dcache as RAM */
563
564	/* Drain pending loads and stores */
565	mcr	p15, 0, r0, c7, c10, 4
566
567	mov	r4, #0x00
568	mov	r5, #0x00
569	mov	r2, #0x01
570	mcr	p15, 0, r0, c9, c2, 0
571	CPWAIT	r0
572
573	/* 128 lines reserved (128 x 32bytes = 4096 bytes total) */
574	mov	r0, #128
575	ldr	r1, =0xfffff000
576
577alloc:
578	mcr	p15, 0, r1, c7, c2, 5
579	/* Drain pending loads and stores */
580	mcr	p15, 0, r0, c7, c10, 4
581	strd	r4, [r1], #8
582	strd	r4, [r1], #8
583	strd	r4, [r1], #8
584	strd	r4, [r1], #8
585	subs	r0, #0x01
586	bne	alloc
587	/* Drain pending loads and stores */
588	mcr	p15, 0, r0, c7, c10, 4
589	mov	r2, #0x00
590	mcr	p15, 0, r2, c9, c2, 0
591	CPWAIT	r0
592
593	mov	pc, lr
594
595.section .mmutable, "a"
596mmutable:
597	.align	14
598	/* 0x00000000 - 0xffe00000 : 1:1, uncached mapping */
599	.set	__base, 0
600	.rept	0xfff
601	.word	(__base << 20) | 0xc12
602	.set	__base, __base + 1
603	.endr
604
605	/* 0xfff00000 : 1:1, cached mapping */
606	.word	(0xfff << 20) | 0x1c1e
607#endif	/* CONFIG_CPU_PXA25X */
608