xref: /rk3399_rockchip-uboot/arch/arm/cpu/arm720t/start.S (revision b52da2aed8c2c388661f369052a97d5b5c9ed00a)
1/*
2 *  armboot - Startup Code for ARM720 CPU-core
3 *
4 *  Copyright (c) 2001	Marius Gr�ger <mag@sysgo.de>
5 *  Copyright (c) 2002	Alex Z�pke <azu@sysgo.de>
6 *
7 * See file CREDITS for list of people who contributed to this
8 * project.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of
13 * the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
23 * MA 02111-1307 USA
24 */
25
26#include <asm-offsets.h>
27#include <config.h>
28#include <version.h>
29#include <asm/hardware.h>
30
31/*
32 *************************************************************************
33 *
34 * Jump vector table as in table 3.1 in [1]
35 *
36 *************************************************************************
37 */
38
39
40.globl _start
41_start: b	reset
42	ldr	pc, _undefined_instruction
43	ldr	pc, _software_interrupt
44	ldr	pc, _prefetch_abort
45	ldr	pc, _data_abort
46#ifdef CONFIG_LPC2292
47	.word	0xB4405F76 /* 2's complement of the checksum of the vectors */
48#else
49	ldr	pc, _not_used
50#endif
51	ldr	pc, _irq
52	ldr	pc, _fiq
53
54_undefined_instruction: .word undefined_instruction
55_software_interrupt:	.word software_interrupt
56_prefetch_abort:	.word prefetch_abort
57_data_abort:		.word data_abort
58_not_used:		.word not_used
59_irq:			.word irq
60_fiq:			.word fiq
61
62	.balignl 16,0xdeadbeef
63
64
65/*
66 *************************************************************************
67 *
68 * Startup Code (reset vector)
69 *
70 * do important init only if we don't start from RAM!
71 * relocate armboot to ram
72 * setup stack
73 * jump to second stage
74 *
75 *************************************************************************
76 */
77
78.globl _TEXT_BASE
79_TEXT_BASE:
80	.word	CONFIG_SYS_TEXT_BASE
81
82/*
83 * These are defined in the board-specific linker script.
84 * Subtracting _start from them lets the linker put their
85 * relative position in the executable instead of leaving
86 * them null.
87 */
88.globl _bss_start_ofs
89_bss_start_ofs:
90	.word __bss_start - _start
91
92.globl _bss_end_ofs
93_bss_end_ofs:
94	.word _end - _start
95
96#ifdef CONFIG_USE_IRQ
97/* IRQ stack memory (calculated at run-time) */
98.globl IRQ_STACK_START
99IRQ_STACK_START:
100	.word	0x0badc0de
101
102/* IRQ stack memory (calculated at run-time) */
103.globl FIQ_STACK_START
104FIQ_STACK_START:
105	.word 0x0badc0de
106#endif
107
108/* IRQ stack memory (calculated at run-time) + 8 bytes */
109.globl IRQ_STACK_START_IN
110IRQ_STACK_START_IN:
111	.word	0x0badc0de
112
113/*
114 * the actual reset code
115 */
116
117reset:
118	/*
119	 * set the cpu to SVC32 mode
120	 */
121	mrs	r0,cpsr
122	bic	r0,r0,#0x1f
123	orr	r0,r0,#0xd3
124	msr	cpsr,r0
125
126	/*
127	 * we do sys-critical inits only at reboot,
128	 * not when booting from ram!
129	 */
130#ifndef CONFIG_SKIP_LOWLEVEL_INIT
131	bl	cpu_init_crit
132#endif
133
134#ifdef CONFIG_LPC2292
135	bl	lowlevel_init
136#endif
137
138/* Set stackpointer in internal RAM to call board_init_f */
139call_board_init_f:
140	ldr	sp, =(CONFIG_SYS_INIT_SP_ADDR)
141	bic	sp, sp, #7 /* 8-byte alignment for ABI compliance */
142	ldr	r0,=0x00000000
143	bl	board_init_f
144
145/*------------------------------------------------------------------------------*/
146
147/*
148 * void relocate_code (addr_sp, gd, addr_moni)
149 *
150 * This "function" does not return, instead it continues in RAM
151 * after relocating the monitor code.
152 *
153 */
154	.globl	relocate_code
155relocate_code:
156	mov	r4, r0	/* save addr_sp */
157	mov	r5, r1	/* save addr of gd */
158	mov	r6, r2	/* save addr of destination */
159
160	/* Set up the stack						    */
161stack_setup:
162	mov	sp, r4
163
164	adr	r0, _start
165	cmp	r0, r6
166	beq	clear_bss		/* skip relocation */
167	mov	r1, r6			/* r1 <- scratch for copy_loop */
168	ldr	r3, _bss_start_ofs
169	add	r2, r0, r3		/* r2 <- source end address	    */
170
171copy_loop:
172	ldmia	r0!, {r9-r10}		/* copy from source address [r0]    */
173	stmia	r1!, {r9-r10}		/* copy to   target address [r1]    */
174	cmp	r0, r2			/* until source end address [r2]    */
175	blo	copy_loop
176
177#ifndef CONFIG_PRELOADER
178	/*
179	 * fix .rel.dyn relocations
180	 */
181	ldr	r0, _TEXT_BASE		/* r0 <- Text base */
182	sub	r9, r6, r0		/* r9 <- relocation offset */
183	ldr	r10, _dynsym_start_ofs	/* r10 <- sym table ofs */
184	add	r10, r10, r0		/* r10 <- sym table in FLASH */
185	ldr	r2, _rel_dyn_start_ofs	/* r2 <- rel dyn start ofs */
186	add	r2, r2, r0		/* r2 <- rel dyn start in FLASH */
187	ldr	r3, _rel_dyn_end_ofs	/* r3 <- rel dyn end ofs */
188	add	r3, r3, r0		/* r3 <- rel dyn end in FLASH */
189fixloop:
190	ldr	r0, [r2]		/* r0 <- location to fix up, IN FLASH! */
191	add	r0, r0, r9		/* r0 <- location to fix up in RAM */
192	ldr	r1, [r2, #4]
193	and	r7, r1, #0xff
194	cmp	r7, #23			/* relative fixup? */
195	beq	fixrel
196	cmp	r7, #2			/* absolute fixup? */
197	beq	fixabs
198	/* ignore unknown type of fixup */
199	b	fixnext
200fixabs:
201	/* absolute fix: set location to (offset) symbol value */
202	mov	r1, r1, LSR #4		/* r1 <- symbol index in .dynsym */
203	add	r1, r10, r1		/* r1 <- address of symbol in table */
204	ldr	r1, [r1, #4]		/* r1 <- symbol value */
205	add	r1, r1, r9		/* r1 <- relocated sym addr */
206	b	fixnext
207fixrel:
208	/* relative fix: increase location by offset */
209	ldr	r1, [r0]
210	add	r1, r1, r9
211fixnext:
212	str	r1, [r0]
213	add	r2, r2, #8		/* each rel.dyn entry is 8 bytes */
214	cmp	r2, r3
215	blo	fixloop
216#endif
217
218clear_bss:
219#ifndef CONFIG_PRELOADER
220	ldr	r0, _bss_start_ofs
221	ldr	r1, _bss_end_ofs
222	mov	r4, r6			/* reloc addr */
223	add	r0, r0, r4
224	add	r1, r1, r4
225	mov	r2, #0x00000000		/* clear			    */
226
227clbss_l:str	r2, [r0]		/* clear loop...		    */
228	add	r0, r0, #4
229	cmp	r0, r1
230	bne	clbss_l
231
232	bl coloured_LED_init
233	bl red_LED_on
234#endif
235
236/*
237 * We are done. Do not return, instead branch to second part of board
238 * initialization, now running from RAM.
239 */
240	ldr	r0, _board_init_r_ofs
241	adr	r1, _start
242	add	lr, r0, r1
243	add	lr, lr, r9
244	/* setup parameters for board_init_r */
245	mov	r0, r5		/* gd_t */
246	mov	r1, r6		/* dest_addr */
247	/* jump to it ... */
248	mov	pc, lr
249
250_board_init_r_ofs:
251	.word board_init_r - _start
252
253_rel_dyn_start_ofs:
254	.word __rel_dyn_start - _start
255_rel_dyn_end_ofs:
256	.word __rel_dyn_end - _start
257_dynsym_start_ofs:
258	.word __dynsym_start - _start
259
260/*
261 *************************************************************************
262 *
263 * CPU_init_critical registers
264 *
265 * setup important registers
266 * setup memory timing
267 *
268 *************************************************************************
269 */
270
271#if defined(CONFIG_IMPA7) || defined(CONFIG_EP7312) || defined(CONFIG_ARMADILLO)
272
273/* Interupt-Controller base addresses */
274INTMR1:		.word	0x80000280 @ 32 bit size
275INTMR2:		.word	0x80001280 @ 16 bit size
276INTMR3:		.word	0x80002280 @  8 bit size
277
278/* SYSCONs */
279SYSCON1:	.word	0x80000100
280SYSCON2:	.word	0x80001100
281SYSCON3:	.word	0x80002200
282
283#define CLKCTL	       0x6  /* mask */
284#define CLKCTL_18      0x0  /* 18.432 MHz */
285#define CLKCTL_36      0x2  /* 36.864 MHz */
286#define CLKCTL_49      0x4  /* 49.152 MHz */
287#define CLKCTL_73      0x6  /* 73.728 MHz */
288
289#elif defined(CONFIG_LPC2292)
290PLLCFG_ADR:	.word	PLLCFG
291PLLFEED_ADR:	.word	PLLFEED
292PLLCON_ADR:	.word	PLLCON
293PLLSTAT_ADR:	.word	PLLSTAT
294VPBDIV_ADR:	.word	VPBDIV
295MEMMAP_ADR:	.word	MEMMAP
296
297#endif
298
299cpu_init_crit:
300#if defined(CONFIG_IMPA7) || defined(CONFIG_EP7312) || defined(CONFIG_ARMADILLO)
301
302	/*
303	 * mask all IRQs by clearing all bits in the INTMRs
304	 */
305	mov	r1, #0x00
306	ldr	r0, INTMR1
307	str	r1, [r0]
308	ldr	r0, INTMR2
309	str	r1, [r0]
310	ldr	r0, INTMR3
311	str	r1, [r0]
312
313	/*
314	 * flush v4 I/D caches
315	 */
316	mov	r0, #0
317	mcr	p15, 0, r0, c7, c7, 0	/* flush v3/v4 cache */
318	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
319
320	/*
321	 * disable MMU stuff and caches
322	 */
323	mrc	p15,0,r0,c1,c0
324	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
325	bic	r0, r0, #0x0000008f	@ clear bits 7, 3:0 (B--- WCAM)
326	orr	r0, r0, #0x00000002	@ set bit 2 (A) Align
327	mcr	p15,0,r0,c1,c0
328#elif defined(CONFIG_NETARM)
329	/*
330	 * prior to software reset : need to set pin PORTC4 to be *HRESET
331	 */
332	ldr	r0, =NETARM_GEN_MODULE_BASE
333	ldr	r1, =(NETARM_GEN_PORT_MODE(0x10) | \
334			NETARM_GEN_PORT_DIR(0x10))
335	str	r1, [r0, #+NETARM_GEN_PORTC]
336	/*
337	 * software reset : see HW Ref. Guide 8.2.4 : Software Service register
338	 *		    for an explanation of this process
339	 */
340	ldr	r0, =NETARM_GEN_MODULE_BASE
341	ldr	r1, =NETARM_GEN_SW_SVC_RESETA
342	str	r1, [r0, #+NETARM_GEN_SOFTWARE_SERVICE]
343	ldr	r1, =NETARM_GEN_SW_SVC_RESETB
344	str	r1, [r0, #+NETARM_GEN_SOFTWARE_SERVICE]
345	ldr	r1, =NETARM_GEN_SW_SVC_RESETA
346	str	r1, [r0, #+NETARM_GEN_SOFTWARE_SERVICE]
347	ldr	r1, =NETARM_GEN_SW_SVC_RESETB
348	str	r1, [r0, #+NETARM_GEN_SOFTWARE_SERVICE]
349	/*
350	 * setup PLL and System Config
351	 */
352	ldr	r0, =NETARM_GEN_MODULE_BASE
353
354	ldr	r1, =(	NETARM_GEN_SYS_CFG_LENDIAN | \
355			NETARM_GEN_SYS_CFG_BUSFULL | \
356			NETARM_GEN_SYS_CFG_USER_EN | \
357			NETARM_GEN_SYS_CFG_ALIGN_ABORT | \
358			NETARM_GEN_SYS_CFG_BUSARB_INT | \
359			NETARM_GEN_SYS_CFG_BUSMON_EN )
360
361	str	r1, [r0, #+NETARM_GEN_SYSTEM_CONTROL]
362
363#ifndef CONFIG_NETARM_PLL_BYPASS
364	ldr	r1, =(	NETARM_GEN_PLL_CTL_PLLCNT(NETARM_PLL_COUNT_VAL) | \
365			NETARM_GEN_PLL_CTL_POLTST_DEF | \
366			NETARM_GEN_PLL_CTL_INDIV(1) | \
367			NETARM_GEN_PLL_CTL_ICP_DEF | \
368			NETARM_GEN_PLL_CTL_OUTDIV(2) )
369	str	r1, [r0, #+NETARM_GEN_PLL_CONTROL]
370#endif
371
372	/*
373	 * mask all IRQs by clearing all bits in the INTMRs
374	 */
375	mov	r1, #0
376	ldr	r0, =NETARM_GEN_MODULE_BASE
377	str	r1, [r0, #+NETARM_GEN_INTR_ENABLE]
378
379#elif defined(CONFIG_S3C4510B)
380
381	/*
382	 * Mask off all IRQ sources
383	 */
384	ldr	r1, =REG_INTMASK
385	ldr	r0, =0x3FFFFF
386	str	r0, [r1]
387
388	/*
389	 * Disable Cache
390	 */
391	ldr r0, =REG_SYSCFG
392	ldr r1, =0x83ffffa0	/* cache-disabled  */
393	str r1, [r0]
394
395#elif defined(CONFIG_INTEGRATOR) && defined(CONFIG_ARCH_INTEGRATOR)
396	/* No specific initialisation for IntegratorAP/CM720T as yet */
397#elif defined(CONFIG_LPC2292)
398	/* Set-up PLL */
399	mov	r3, #0xAA
400	mov	r4, #0x55
401	/* First disconnect and disable the PLL */
402	ldr	r0, PLLCON_ADR
403	mov	r1, #0x00
404	str	r1, [r0]
405	ldr	r0, PLLFEED_ADR /* start feed sequence */
406	str	r3, [r0]
407	str	r4, [r0]	/* feed sequence done */
408	/* Set new M and P values */
409	ldr	r0, PLLCFG_ADR
410	mov	r1, #0x23	/* M=4 and P=2 */
411	str	r1, [r0]
412	ldr	r0, PLLFEED_ADR /* start feed sequence */
413	str	r3, [r0]
414	str	r4, [r0]	/* feed sequence done */
415	/* Then enable the PLL */
416	ldr	r0, PLLCON_ADR
417	mov	r1, #0x01	/* PLL enable bit */
418	str	r1, [r0]
419	ldr	r0, PLLFEED_ADR /* start feed sequence */
420	str	r3, [r0]
421	str	r4, [r0]	/* feed sequence done */
422	/* Wait for the lock */
423	ldr	r0, PLLSTAT_ADR
424	mov	r1, #0x400	/* lock bit */
425lock_loop:
426	ldr	r2, [r0]
427	and	r2, r1, r2
428	cmp	r2, #0
429	beq	lock_loop
430	/* And finally connect the PLL */
431	ldr	r0, PLLCON_ADR
432	mov	r1, #0x03	/* PLL enable bit and connect bit */
433	str	r1, [r0]
434	ldr	r0, PLLFEED_ADR /* start feed sequence */
435	str	r3, [r0]
436	str	r4, [r0]	/* feed sequence done */
437	/* Set-up VPBDIV register */
438	ldr	r0, VPBDIV_ADR
439	mov	r1, #0x01	/* VPB clock is same as process clock */
440	str	r1, [r0]
441#else
442#error No cpu_init_crit() defined for current CPU type
443#endif
444
445#ifdef CONFIG_ARM7_REVD
446	/* set clock speed */
447	/* !!! we run @ 36 MHz due to a hardware flaw in Rev. D processors */
448	/* !!! not doing DRAM refresh properly! */
449	ldr	r0, SYSCON3
450	ldr	r1, [r0]
451	bic	r1, r1, #CLKCTL
452	orr	r1, r1, #CLKCTL_36
453	str	r1, [r0]
454#endif
455
456#ifndef CONFIG_LPC2292
457	mov	ip, lr
458	/*
459	 * before relocating, we have to setup RAM timing
460	 * because memory timing is board-dependent, you will
461	 * find a lowlevel_init.S in your board directory.
462	 */
463	bl	lowlevel_init
464	mov	lr, ip
465#endif
466
467	mov	pc, lr
468
469
470/*
471 *************************************************************************
472 *
473 * Interrupt handling
474 *
475 *************************************************************************
476 */
477
478@
479@ IRQ stack frame.
480@
481#define S_FRAME_SIZE	72
482
483#define S_OLD_R0	68
484#define S_PSR		64
485#define S_PC		60
486#define S_LR		56
487#define S_SP		52
488
489#define S_IP		48
490#define S_FP		44
491#define S_R10		40
492#define S_R9		36
493#define S_R8		32
494#define S_R7		28
495#define S_R6		24
496#define S_R5		20
497#define S_R4		16
498#define S_R3		12
499#define S_R2		8
500#define S_R1		4
501#define S_R0		0
502
503#define MODE_SVC 0x13
504#define I_BIT	 0x80
505
506/*
507 * use bad_save_user_regs for abort/prefetch/undef/swi ...
508 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
509 */
510
511	.macro	bad_save_user_regs
512	sub	sp, sp, #S_FRAME_SIZE
513	stmia	sp, {r0 - r12}			@ Calling r0-r12
514	add	r8, sp, #S_PC
515
516	ldr	r2, IRQ_STACK_START_IN
517	ldmia	r2, {r2 - r4}			@ get pc, cpsr, old_r0
518	add	r0, sp, #S_FRAME_SIZE		@ restore sp_SVC
519
520	add	r5, sp, #S_SP
521	mov	r1, lr
522	stmia	r5, {r0 - r4}			@ save sp_SVC, lr_SVC, pc, cpsr, old_r
523	mov	r0, sp
524	.endm
525
526	.macro	irq_save_user_regs
527	sub	sp, sp, #S_FRAME_SIZE
528	stmia	sp, {r0 - r12}			@ Calling r0-r12
529	add	r8, sp, #S_PC
530	stmdb	r8, {sp, lr}^			@ Calling SP, LR
531	str	lr, [r8, #0]			@ Save calling PC
532	mrs	r6, spsr
533	str	r6, [r8, #4]			@ Save CPSR
534	str	r0, [r8, #8]			@ Save OLD_R0
535	mov	r0, sp
536	.endm
537
538	.macro	irq_restore_user_regs
539	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
540	mov	r0, r0
541	ldr	lr, [sp, #S_PC]			@ Get PC
542	add	sp, sp, #S_FRAME_SIZE
543	subs	pc, lr, #4			@ return & move spsr_svc into cpsr
544	.endm
545
546	.macro get_bad_stack
547	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
548
549	str	lr, [r13]			@ save caller lr / spsr
550	mrs	lr, spsr
551	str	lr, [r13, #4]
552
553	mov	r13, #MODE_SVC			@ prepare SVC-Mode
554	msr	spsr_c, r13
555	mov	lr, pc
556	movs	pc, lr
557	.endm
558
559	.macro get_irq_stack			@ setup IRQ stack
560	ldr	sp, IRQ_STACK_START
561	.endm
562
563	.macro get_fiq_stack			@ setup FIQ stack
564	ldr	sp, FIQ_STACK_START
565	.endm
566
567/*
568 * exception handlers
569 */
570	.align	5
571undefined_instruction:
572	get_bad_stack
573	bad_save_user_regs
574	bl	do_undefined_instruction
575
576	.align	5
577software_interrupt:
578	get_bad_stack
579	bad_save_user_regs
580	bl	do_software_interrupt
581
582	.align	5
583prefetch_abort:
584	get_bad_stack
585	bad_save_user_regs
586	bl	do_prefetch_abort
587
588	.align	5
589data_abort:
590	get_bad_stack
591	bad_save_user_regs
592	bl	do_data_abort
593
594	.align	5
595not_used:
596	get_bad_stack
597	bad_save_user_regs
598	bl	do_not_used
599
600#ifdef CONFIG_USE_IRQ
601
602	.align	5
603irq:
604	get_irq_stack
605	irq_save_user_regs
606	bl	do_irq
607	irq_restore_user_regs
608
609	.align	5
610fiq:
611	get_fiq_stack
612	/* someone ought to write a more effiction fiq_save_user_regs */
613	irq_save_user_regs
614	bl	do_fiq
615	irq_restore_user_regs
616
617#else
618
619	.align	5
620irq:
621	get_bad_stack
622	bad_save_user_regs
623	bl	do_irq
624
625	.align	5
626fiq:
627	get_bad_stack
628	bad_save_user_regs
629	bl	do_fiq
630
631#endif
632
633#if defined(CONFIG_IMPA7) || defined(CONFIG_EP7312) || defined(CONFIG_ARMADILLO)
634	.align	5
635.globl reset_cpu
636reset_cpu:
637	mov	ip, #0
638	mcr	p15, 0, ip, c7, c7, 0		@ invalidate cache
639	mcr	p15, 0, ip, c8, c7, 0		@ flush TLB (v4)
640	mrc	p15, 0, ip, c1, c0, 0		@ get ctrl register
641	bic	ip, ip, #0x000f			@ ............wcam
642	bic	ip, ip, #0x2100			@ ..v....s........
643	mcr	p15, 0, ip, c1, c0, 0		@ ctrl register
644	mov	pc, r0
645#elif defined(CONFIG_NETARM)
646	.align	5
647.globl reset_cpu
648reset_cpu:
649	ldr	r1, =NETARM_MEM_MODULE_BASE
650	ldr	r0, [r1, #+NETARM_MEM_CS0_BASE_ADDR]
651	ldr	r1, =0xFFFFF000
652	and	r0, r1, r0
653	ldr	r1, =(relocate-CONFIG_SYS_TEXT_BASE)
654	add	r0, r1, r0
655	ldr	r4, =NETARM_GEN_MODULE_BASE
656	ldr	r1, =NETARM_GEN_SW_SVC_RESETA
657	str	r1, [r4, #+NETARM_GEN_SOFTWARE_SERVICE]
658	ldr	r1, =NETARM_GEN_SW_SVC_RESETB
659	str	r1, [r4, #+NETARM_GEN_SOFTWARE_SERVICE]
660	ldr	r1, =NETARM_GEN_SW_SVC_RESETA
661	str	r1, [r4, #+NETARM_GEN_SOFTWARE_SERVICE]
662	ldr	r1, =NETARM_GEN_SW_SVC_RESETB
663	str	r1, [r4, #+NETARM_GEN_SOFTWARE_SERVICE]
664	mov	pc, r0
665#elif defined(CONFIG_S3C4510B)
666/* Nothing done here as reseting the CPU is board specific, depending
667 * on external peripherals such as watchdog timers, etc. */
668#elif defined(CONFIG_INTEGRATOR) && defined(CONFIG_ARCH_INTEGRATOR)
669	/* No specific reset actions for IntegratorAP/CM720T as yet */
670#elif defined(CONFIG_LPC2292)
671	.align	5
672.globl reset_cpu
673reset_cpu:
674	mov	pc, r0
675#else
676#error No reset_cpu() defined for current CPU type
677#endif
678