xref: /openbmc/u-boot/arch/arm/cpu/arm720t/start.S (revision 6d8962e814c15807dd6ac5757904be2a02d187b8)
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 */
85.globl _bss_start
86_bss_start:
87	.word __bss_start
88
89.globl _bss_end
90_bss_end:
91	.word _end
92
93#ifdef CONFIG_USE_IRQ
94/* IRQ stack memory (calculated at run-time) */
95.globl IRQ_STACK_START
96IRQ_STACK_START:
97	.word	0x0badc0de
98
99/* IRQ stack memory (calculated at run-time) */
100.globl FIQ_STACK_START
101FIQ_STACK_START:
102	.word 0x0badc0de
103#endif
104
105/* IRQ stack memory (calculated at run-time) + 8 bytes */
106.globl IRQ_STACK_START_IN
107IRQ_STACK_START_IN:
108	.word	0x0badc0de
109
110.globl _datarel_start
111_datarel_start:
112	.word __datarel_start
113
114.globl _datarelrolocal_start
115_datarelrolocal_start:
116	.word __datarelrolocal_start
117
118.globl _datarellocal_start
119_datarellocal_start:
120	.word __datarellocal_start
121
122.globl _datarelro_start
123_datarelro_start:
124	.word __datarelro_start
125
126.globl _got_start
127_got_start:
128	.word __got_start
129
130.globl _got_end
131_got_end:
132	.word __got_end
133
134/*
135 * the actual reset code
136 */
137
138reset:
139	/*
140	 * set the cpu to SVC32 mode
141	 */
142	mrs	r0,cpsr
143	bic	r0,r0,#0x1f
144	orr	r0,r0,#0xd3
145	msr	cpsr,r0
146
147	/*
148	 * we do sys-critical inits only at reboot,
149	 * not when booting from ram!
150	 */
151#ifndef CONFIG_SKIP_LOWLEVEL_INIT
152	bl	cpu_init_crit
153#endif
154
155#ifdef CONFIG_LPC2292
156	bl	lowlevel_init
157#endif
158
159/* Set stackpointer in internal RAM to call board_init_f */
160call_board_init_f:
161	ldr	sp, =(CONFIG_SYS_INIT_SP_ADDR)
162	ldr	r0,=0x00000000
163	bl	board_init_f
164
165/*------------------------------------------------------------------------------*/
166
167/*
168 * void relocate_code (addr_sp, gd, addr_moni)
169 *
170 * This "function" does not return, instead it continues in RAM
171 * after relocating the monitor code.
172 *
173 */
174	.globl	relocate_code
175relocate_code:
176	mov	r4, r0	/* save addr_sp */
177	mov	r5, r1	/* save addr of gd */
178	mov	r6, r2	/* save addr of destination */
179	mov	r7, r2	/* save addr of destination */
180
181	/* Set up the stack						    */
182stack_setup:
183	mov	sp, r4
184
185	adr	r0, _start
186	ldr	r2, _TEXT_BASE
187	ldr	r3, _bss_start
188	sub	r2, r3, r2		/* r2 <- size of armboot	    */
189	add	r2, r0, r2		/* r2 <- source end address	    */
190	cmp	r0, r6
191	beq	clear_bss
192
193copy_loop:
194	ldmia	r0!, {r9-r10}		/* copy from source address [r0]    */
195	stmia	r6!, {r9-r10}		/* copy to   target address [r1]    */
196	cmp	r0, r2			/* until source end address [r2]    */
197	blo	copy_loop
198
199#ifndef CONFIG_PRELOADER
200	/* fix got entries */
201	ldr	r1, _TEXT_BASE		/* Text base */
202	mov	r0, r7			/* reloc addr */
203	ldr	r2, _got_start		/* addr in Flash */
204	ldr	r3, _got_end		/* addr in Flash */
205	sub	r3, r3, r1
206	add	r3, r3, r0
207	sub	r2, r2, r1
208	add	r2, r2, r0
209
210fixloop:
211	ldr	r4, [r2]
212	sub	r4, r4, r1
213	add	r4, r4, r0
214	str	r4, [r2]
215	add	r2, r2, #4
216	cmp	r2, r3
217	blo	fixloop
218#endif
219
220clear_bss:
221#ifndef CONFIG_PRELOADER
222	ldr	r0, _bss_start
223	ldr	r1, _bss_end
224	ldr	r3, _TEXT_BASE		/* Text base */
225	mov	r4, r7			/* reloc addr */
226	sub	r0, r0, r3
227	add	r0, r0, r4
228	sub	r1, r1, r3
229	add	r1, r1, r4
230	mov	r2, #0x00000000		/* clear			    */
231
232clbss_l:str	r2, [r0]		/* clear loop...		    */
233	add	r0, r0, #4
234	cmp	r0, r1
235	bne	clbss_l
236
237	bl coloured_LED_init
238	bl red_LED_on
239#endif
240
241/*
242 * We are done. Do not return, instead branch to second part of board
243 * initialization, now running from RAM.
244 */
245	ldr	r0, _TEXT_BASE
246	ldr	r2, _board_init_r
247	sub	r2, r2, r0
248	add	r2, r2, r7	/* position from board_init_r in RAM */
249	/* setup parameters for board_init_r */
250	mov	r0, r5		/* gd_t */
251	mov	r1, r7		/* dest_addr */
252	/* jump to it ... */
253	mov	lr, r2
254	mov	pc, lr
255
256_board_init_r: .word board_init_r
257
258/*
259 *************************************************************************
260 *
261 * CPU_init_critical registers
262 *
263 * setup important registers
264 * setup memory timing
265 *
266 *************************************************************************
267 */
268
269#if defined(CONFIG_IMPA7) || defined(CONFIG_EP7312) || defined(CONFIG_ARMADILLO)
270
271/* Interupt-Controller base addresses */
272INTMR1:		.word	0x80000280 @ 32 bit size
273INTMR2:		.word	0x80001280 @ 16 bit size
274INTMR3:		.word	0x80002280 @  8 bit size
275
276/* SYSCONs */
277SYSCON1:	.word	0x80000100
278SYSCON2:	.word	0x80001100
279SYSCON3:	.word	0x80002200
280
281#define CLKCTL	       0x6  /* mask */
282#define CLKCTL_18      0x0  /* 18.432 MHz */
283#define CLKCTL_36      0x2  /* 36.864 MHz */
284#define CLKCTL_49      0x4  /* 49.152 MHz */
285#define CLKCTL_73      0x6  /* 73.728 MHz */
286
287#elif defined(CONFIG_LPC2292)
288PLLCFG_ADR:	.word	PLLCFG
289PLLFEED_ADR:	.word	PLLFEED
290PLLCON_ADR:	.word	PLLCON
291PLLSTAT_ADR:	.word	PLLSTAT
292VPBDIV_ADR:	.word	VPBDIV
293MEMMAP_ADR:	.word	MEMMAP
294
295#endif
296
297cpu_init_crit:
298#if defined(CONFIG_IMPA7) || defined(CONFIG_EP7312) || defined(CONFIG_ARMADILLO)
299
300	/*
301	 * mask all IRQs by clearing all bits in the INTMRs
302	 */
303	mov	r1, #0x00
304	ldr	r0, INTMR1
305	str	r1, [r0]
306	ldr	r0, INTMR2
307	str	r1, [r0]
308	ldr	r0, INTMR3
309	str	r1, [r0]
310
311	/*
312	 * flush v4 I/D caches
313	 */
314	mov	r0, #0
315	mcr	p15, 0, r0, c7, c7, 0	/* flush v3/v4 cache */
316	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
317
318	/*
319	 * disable MMU stuff and caches
320	 */
321	mrc	p15,0,r0,c1,c0
322	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
323	bic	r0, r0, #0x0000008f	@ clear bits 7, 3:0 (B--- WCAM)
324	orr	r0, r0, #0x00000002	@ set bit 2 (A) Align
325	mcr	p15,0,r0,c1,c0
326#elif defined(CONFIG_NETARM)
327	/*
328	 * prior to software reset : need to set pin PORTC4 to be *HRESET
329	 */
330	ldr	r0, =NETARM_GEN_MODULE_BASE
331	ldr	r1, =(NETARM_GEN_PORT_MODE(0x10) | \
332			NETARM_GEN_PORT_DIR(0x10))
333	str	r1, [r0, #+NETARM_GEN_PORTC]
334	/*
335	 * software reset : see HW Ref. Guide 8.2.4 : Software Service register
336	 *		    for an explanation of this process
337	 */
338	ldr	r0, =NETARM_GEN_MODULE_BASE
339	ldr	r1, =NETARM_GEN_SW_SVC_RESETA
340	str	r1, [r0, #+NETARM_GEN_SOFTWARE_SERVICE]
341	ldr	r1, =NETARM_GEN_SW_SVC_RESETB
342	str	r1, [r0, #+NETARM_GEN_SOFTWARE_SERVICE]
343	ldr	r1, =NETARM_GEN_SW_SVC_RESETA
344	str	r1, [r0, #+NETARM_GEN_SOFTWARE_SERVICE]
345	ldr	r1, =NETARM_GEN_SW_SVC_RESETB
346	str	r1, [r0, #+NETARM_GEN_SOFTWARE_SERVICE]
347	/*
348	 * setup PLL and System Config
349	 */
350	ldr	r0, =NETARM_GEN_MODULE_BASE
351
352	ldr	r1, =(	NETARM_GEN_SYS_CFG_LENDIAN | \
353			NETARM_GEN_SYS_CFG_BUSFULL | \
354			NETARM_GEN_SYS_CFG_USER_EN | \
355			NETARM_GEN_SYS_CFG_ALIGN_ABORT | \
356			NETARM_GEN_SYS_CFG_BUSARB_INT | \
357			NETARM_GEN_SYS_CFG_BUSMON_EN )
358
359	str	r1, [r0, #+NETARM_GEN_SYSTEM_CONTROL]
360
361#ifndef CONFIG_NETARM_PLL_BYPASS
362	ldr	r1, =(	NETARM_GEN_PLL_CTL_PLLCNT(NETARM_PLL_COUNT_VAL) | \
363			NETARM_GEN_PLL_CTL_POLTST_DEF | \
364			NETARM_GEN_PLL_CTL_INDIV(1) | \
365			NETARM_GEN_PLL_CTL_ICP_DEF | \
366			NETARM_GEN_PLL_CTL_OUTDIV(2) )
367	str	r1, [r0, #+NETARM_GEN_PLL_CONTROL]
368#endif
369
370	/*
371	 * mask all IRQs by clearing all bits in the INTMRs
372	 */
373	mov	r1, #0
374	ldr	r0, =NETARM_GEN_MODULE_BASE
375	str	r1, [r0, #+NETARM_GEN_INTR_ENABLE]
376
377#elif defined(CONFIG_S3C4510B)
378
379	/*
380	 * Mask off all IRQ sources
381	 */
382	ldr	r1, =REG_INTMASK
383	ldr	r0, =0x3FFFFF
384	str	r0, [r1]
385
386	/*
387	 * Disable Cache
388	 */
389	ldr r0, =REG_SYSCFG
390	ldr r1, =0x83ffffa0	/* cache-disabled  */
391	str r1, [r0]
392
393#elif defined(CONFIG_INTEGRATOR) && defined(CONFIG_ARCH_INTEGRATOR)
394	/* No specific initialisation for IntegratorAP/CM720T as yet */
395#elif defined(CONFIG_LPC2292)
396	/* Set-up PLL */
397	mov	r3, #0xAA
398	mov	r4, #0x55
399	/* First disconnect and disable the PLL */
400	ldr	r0, PLLCON_ADR
401	mov	r1, #0x00
402	str	r1, [r0]
403	ldr	r0, PLLFEED_ADR /* start feed sequence */
404	str	r3, [r0]
405	str	r4, [r0]	/* feed sequence done */
406	/* Set new M and P values */
407	ldr	r0, PLLCFG_ADR
408	mov	r1, #0x23	/* M=4 and P=2 */
409	str	r1, [r0]
410	ldr	r0, PLLFEED_ADR /* start feed sequence */
411	str	r3, [r0]
412	str	r4, [r0]	/* feed sequence done */
413	/* Then enable the PLL */
414	ldr	r0, PLLCON_ADR
415	mov	r1, #0x01	/* PLL enable bit */
416	str	r1, [r0]
417	ldr	r0, PLLFEED_ADR /* start feed sequence */
418	str	r3, [r0]
419	str	r4, [r0]	/* feed sequence done */
420	/* Wait for the lock */
421	ldr	r0, PLLSTAT_ADR
422	mov	r1, #0x400	/* lock bit */
423lock_loop:
424	ldr	r2, [r0]
425	and	r2, r1, r2
426	cmp	r2, #0
427	beq	lock_loop
428	/* And finally connect the PLL */
429	ldr	r0, PLLCON_ADR
430	mov	r1, #0x03	/* PLL enable bit and connect bit */
431	str	r1, [r0]
432	ldr	r0, PLLFEED_ADR /* start feed sequence */
433	str	r3, [r0]
434	str	r4, [r0]	/* feed sequence done */
435	/* Set-up VPBDIV register */
436	ldr	r0, VPBDIV_ADR
437	mov	r1, #0x01	/* VPB clock is same as process clock */
438	str	r1, [r0]
439#else
440#error No cpu_init_crit() defined for current CPU type
441#endif
442
443#ifdef CONFIG_ARM7_REVD
444	/* set clock speed */
445	/* !!! we run @ 36 MHz due to a hardware flaw in Rev. D processors */
446	/* !!! not doing DRAM refresh properly! */
447	ldr	r0, SYSCON3
448	ldr	r1, [r0]
449	bic	r1, r1, #CLKCTL
450	orr	r1, r1, #CLKCTL_36
451	str	r1, [r0]
452#endif
453
454#ifndef CONFIG_LPC2292
455	mov	ip, lr
456	/*
457	 * before relocating, we have to setup RAM timing
458	 * because memory timing is board-dependent, you will
459	 * find a lowlevel_init.S in your board directory.
460	 */
461	bl	lowlevel_init
462	mov	lr, ip
463#endif
464
465	mov	pc, lr
466
467
468/*
469 *************************************************************************
470 *
471 * Interrupt handling
472 *
473 *************************************************************************
474 */
475
476@
477@ IRQ stack frame.
478@
479#define S_FRAME_SIZE	72
480
481#define S_OLD_R0	68
482#define S_PSR		64
483#define S_PC		60
484#define S_LR		56
485#define S_SP		52
486
487#define S_IP		48
488#define S_FP		44
489#define S_R10		40
490#define S_R9		36
491#define S_R8		32
492#define S_R7		28
493#define S_R6		24
494#define S_R5		20
495#define S_R4		16
496#define S_R3		12
497#define S_R2		8
498#define S_R1		4
499#define S_R0		0
500
501#define MODE_SVC 0x13
502#define I_BIT	 0x80
503
504/*
505 * use bad_save_user_regs for abort/prefetch/undef/swi ...
506 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
507 */
508
509	.macro	bad_save_user_regs
510	sub	sp, sp, #S_FRAME_SIZE
511	stmia	sp, {r0 - r12}			@ Calling r0-r12
512	add	r8, sp, #S_PC
513
514	ldr	r2, IRQ_STACK_START_IN
515	ldmia	r2, {r2 - r4}			@ get pc, cpsr, old_r0
516	add	r0, sp, #S_FRAME_SIZE		@ restore sp_SVC
517
518	add	r5, sp, #S_SP
519	mov	r1, lr
520	stmia	r5, {r0 - r4}			@ save sp_SVC, lr_SVC, pc, cpsr, old_r
521	mov	r0, sp
522	.endm
523
524	.macro	irq_save_user_regs
525	sub	sp, sp, #S_FRAME_SIZE
526	stmia	sp, {r0 - r12}			@ Calling r0-r12
527	add	r8, sp, #S_PC
528	stmdb	r8, {sp, lr}^			@ Calling SP, LR
529	str	lr, [r8, #0]			@ Save calling PC
530	mrs	r6, spsr
531	str	r6, [r8, #4]			@ Save CPSR
532	str	r0, [r8, #8]			@ Save OLD_R0
533	mov	r0, sp
534	.endm
535
536	.macro	irq_restore_user_regs
537	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
538	mov	r0, r0
539	ldr	lr, [sp, #S_PC]			@ Get PC
540	add	sp, sp, #S_FRAME_SIZE
541	subs	pc, lr, #4			@ return & move spsr_svc into cpsr
542	.endm
543
544	.macro get_bad_stack
545	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
546
547	str	lr, [r13]			@ save caller lr / spsr
548	mrs	lr, spsr
549	str	lr, [r13, #4]
550
551	mov	r13, #MODE_SVC			@ prepare SVC-Mode
552	msr	spsr_c, r13
553	mov	lr, pc
554	movs	pc, lr
555	.endm
556
557	.macro get_irq_stack			@ setup IRQ stack
558	ldr	sp, IRQ_STACK_START
559	.endm
560
561	.macro get_fiq_stack			@ setup FIQ stack
562	ldr	sp, FIQ_STACK_START
563	.endm
564
565/*
566 * exception handlers
567 */
568	.align	5
569undefined_instruction:
570	get_bad_stack
571	bad_save_user_regs
572	bl	do_undefined_instruction
573
574	.align	5
575software_interrupt:
576	get_bad_stack
577	bad_save_user_regs
578	bl	do_software_interrupt
579
580	.align	5
581prefetch_abort:
582	get_bad_stack
583	bad_save_user_regs
584	bl	do_prefetch_abort
585
586	.align	5
587data_abort:
588	get_bad_stack
589	bad_save_user_regs
590	bl	do_data_abort
591
592	.align	5
593not_used:
594	get_bad_stack
595	bad_save_user_regs
596	bl	do_not_used
597
598#ifdef CONFIG_USE_IRQ
599
600	.align	5
601irq:
602	get_irq_stack
603	irq_save_user_regs
604	bl	do_irq
605	irq_restore_user_regs
606
607	.align	5
608fiq:
609	get_fiq_stack
610	/* someone ought to write a more effiction fiq_save_user_regs */
611	irq_save_user_regs
612	bl	do_fiq
613	irq_restore_user_regs
614
615#else
616
617	.align	5
618irq:
619	get_bad_stack
620	bad_save_user_regs
621	bl	do_irq
622
623	.align	5
624fiq:
625	get_bad_stack
626	bad_save_user_regs
627	bl	do_fiq
628
629#endif
630
631#if defined(CONFIG_IMPA7) || defined(CONFIG_EP7312) || defined(CONFIG_ARMADILLO)
632	.align	5
633.globl reset_cpu
634reset_cpu:
635	mov	ip, #0
636	mcr	p15, 0, ip, c7, c7, 0		@ invalidate cache
637	mcr	p15, 0, ip, c8, c7, 0		@ flush TLB (v4)
638	mrc	p15, 0, ip, c1, c0, 0		@ get ctrl register
639	bic	ip, ip, #0x000f			@ ............wcam
640	bic	ip, ip, #0x2100			@ ..v....s........
641	mcr	p15, 0, ip, c1, c0, 0		@ ctrl register
642	mov	pc, r0
643#elif defined(CONFIG_NETARM)
644	.align	5
645.globl reset_cpu
646reset_cpu:
647	ldr	r1, =NETARM_MEM_MODULE_BASE
648	ldr	r0, [r1, #+NETARM_MEM_CS0_BASE_ADDR]
649	ldr	r1, =0xFFFFF000
650	and	r0, r1, r0
651	ldr	r1, =(relocate-CONFIG_SYS_TEXT_BASE)
652	add	r0, r1, r0
653	ldr	r4, =NETARM_GEN_MODULE_BASE
654	ldr	r1, =NETARM_GEN_SW_SVC_RESETA
655	str	r1, [r4, #+NETARM_GEN_SOFTWARE_SERVICE]
656	ldr	r1, =NETARM_GEN_SW_SVC_RESETB
657	str	r1, [r4, #+NETARM_GEN_SOFTWARE_SERVICE]
658	ldr	r1, =NETARM_GEN_SW_SVC_RESETA
659	str	r1, [r4, #+NETARM_GEN_SOFTWARE_SERVICE]
660	ldr	r1, =NETARM_GEN_SW_SVC_RESETB
661	str	r1, [r4, #+NETARM_GEN_SOFTWARE_SERVICE]
662	mov	pc, r0
663#elif defined(CONFIG_S3C4510B)
664/* Nothing done here as reseting the CPU is board specific, depending
665 * on external peripherals such as watchdog timers, etc. */
666#elif defined(CONFIG_INTEGRATOR) && defined(CONFIG_ARCH_INTEGRATOR)
667	/* No specific reset actions for IntegratorAP/CM720T as yet */
668#elif defined(CONFIG_LPC2292)
669	.align	5
670.globl reset_cpu
671reset_cpu:
672	mov	pc, r0
673#else
674#error No reset_cpu() defined for current CPU type
675#endif
676