xref: /openbmc/u-boot/arch/arm/cpu/arm720t/start.S (revision 7fbeb642) 
1/*
2 *  armboot - Startup Code for ARM720 CPU-core
3 *
4 *  Copyright (c) 2001	Marius Gröger <mag@sysgo.de>
5 *  Copyright (c) 2002	Alex Züpke <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 __bss_end__ - _start
95
96.globl _end_ofs
97_end_ofs:
98	.word _end - _start
99
100#ifdef CONFIG_USE_IRQ
101/* IRQ stack memory (calculated at run-time) */
102.globl IRQ_STACK_START
103IRQ_STACK_START:
104	.word	0x0badc0de
105
106/* IRQ stack memory (calculated at run-time) */
107.globl FIQ_STACK_START
108FIQ_STACK_START:
109	.word 0x0badc0de
110#endif
111
112/* IRQ stack memory (calculated at run-time) + 8 bytes */
113.globl IRQ_STACK_START_IN
114IRQ_STACK_START_IN:
115	.word	0x0badc0de
116
117/*
118 * the actual reset code
119 */
120
121reset:
122	/*
123	 * set the cpu to SVC32 mode
124	 */
125	mrs	r0,cpsr
126	bic	r0,r0,#0x1f
127	orr	r0,r0,#0xd3
128	msr	cpsr,r0
129
130	/*
131	 * we do sys-critical inits only at reboot,
132	 * not when booting from ram!
133	 */
134#ifndef CONFIG_SKIP_LOWLEVEL_INIT
135	bl	cpu_init_crit
136#endif
137
138#ifdef CONFIG_LPC2292
139	bl	lowlevel_init
140#endif
141
142/* Set stackpointer in internal RAM to call board_init_f */
143call_board_init_f:
144	ldr	sp, =(CONFIG_SYS_INIT_SP_ADDR)
145	bic	sp, sp, #7 /* 8-byte alignment for ABI compliance */
146	ldr	r0,=0x00000000
147	bl	board_init_f
148
149/*------------------------------------------------------------------------------*/
150
151/*
152 * void relocate_code (addr_sp, gd, addr_moni)
153 *
154 * This "function" does not return, instead it continues in RAM
155 * after relocating the monitor code.
156 *
157 */
158	.globl	relocate_code
159relocate_code:
160	mov	r4, r0	/* save addr_sp */
161	mov	r5, r1	/* save addr of gd */
162	mov	r6, r2	/* save addr of destination */
163
164	/* Set up the stack						    */
165stack_setup:
166	mov	sp, r4
167
168	adr	r0, _start
169	cmp	r0, r6
170	beq	clear_bss		/* skip relocation */
171	mov	r1, r6			/* r1 <- scratch for copy_loop */
172	ldr	r3, _bss_start_ofs
173	add	r2, r0, r3		/* r2 <- source end address	    */
174
175copy_loop:
176	ldmia	r0!, {r9-r10}		/* copy from source address [r0]    */
177	stmia	r1!, {r9-r10}		/* copy to   target address [r1]    */
178	cmp	r0, r2			/* until source end address [r2]    */
179	blo	copy_loop
180
181#ifndef CONFIG_SPL_BUILD
182	/*
183	 * fix .rel.dyn relocations
184	 */
185	ldr	r0, _TEXT_BASE		/* r0 <- Text base */
186	sub	r9, r6, r0		/* r9 <- relocation offset */
187	ldr	r10, _dynsym_start_ofs	/* r10 <- sym table ofs */
188	add	r10, r10, r0		/* r10 <- sym table in FLASH */
189	ldr	r2, _rel_dyn_start_ofs	/* r2 <- rel dyn start ofs */
190	add	r2, r2, r0		/* r2 <- rel dyn start in FLASH */
191	ldr	r3, _rel_dyn_end_ofs	/* r3 <- rel dyn end ofs */
192	add	r3, r3, r0		/* r3 <- rel dyn end in FLASH */
193fixloop:
194	ldr	r0, [r2]		/* r0 <- location to fix up, IN FLASH! */
195	add	r0, r0, r9		/* r0 <- location to fix up in RAM */
196	ldr	r1, [r2, #4]
197	and	r7, r1, #0xff
198	cmp	r7, #23			/* relative fixup? */
199	beq	fixrel
200	cmp	r7, #2			/* absolute fixup? */
201	beq	fixabs
202	/* ignore unknown type of fixup */
203	b	fixnext
204fixabs:
205	/* absolute fix: set location to (offset) symbol value */
206	mov	r1, r1, LSR #4		/* r1 <- symbol index in .dynsym */
207	add	r1, r10, r1		/* r1 <- address of symbol in table */
208	ldr	r1, [r1, #4]		/* r1 <- symbol value */
209	add	r1, r1, r9		/* r1 <- relocated sym addr */
210	b	fixnext
211fixrel:
212	/* relative fix: increase location by offset */
213	ldr	r1, [r0]
214	add	r1, r1, r9
215fixnext:
216	str	r1, [r0]
217	add	r2, r2, #8		/* each rel.dyn entry is 8 bytes */
218	cmp	r2, r3
219	blo	fixloop
220#endif
221
222clear_bss:
223#ifndef CONFIG_SPL_BUILD
224	ldr	r0, _bss_start_ofs
225	ldr	r1, _bss_end_ofs
226	mov	r4, r6			/* reloc addr */
227	add	r0, r0, r4
228	add	r1, r1, r4
229	mov	r2, #0x00000000		/* clear			    */
230
231clbss_l:str	r2, [r0]		/* clear loop...		    */
232	add	r0, r0, #4
233	cmp	r0, r1
234	bne	clbss_l
235
236	bl coloured_LED_init
237	bl red_LED_on
238#endif
239
240/*
241 * We are done. Do not return, instead branch to second part of board
242 * initialization, now running from RAM.
243 */
244	ldr	r0, _board_init_r_ofs
245	adr	r1, _start
246	add	lr, r0, r1
247	add	lr, lr, r9
248	/* setup parameters for board_init_r */
249	mov	r0, r5		/* gd_t */
250	mov	r1, r6		/* dest_addr */
251	/* jump to it ... */
252	mov	pc, lr
253
254_board_init_r_ofs:
255	.word board_init_r - _start
256
257_rel_dyn_start_ofs:
258	.word __rel_dyn_start - _start
259_rel_dyn_end_ofs:
260	.word __rel_dyn_end - _start
261_dynsym_start_ofs:
262	.word __dynsym_start - _start
263
264/*
265 *************************************************************************
266 *
267 * CPU_init_critical registers
268 *
269 * setup important registers
270 * setup memory timing
271 *
272 *************************************************************************
273 */
274
275#if defined(CONFIG_IMPA7) || defined(CONFIG_EP7312) || defined(CONFIG_ARMADILLO)
276
277/* Interrupt-Controller base addresses */
278INTMR1:		.word	0x80000280 @ 32 bit size
279INTMR2:		.word	0x80001280 @ 16 bit size
280INTMR3:		.word	0x80002280 @  8 bit size
281
282/* SYSCONs */
283SYSCON1:	.word	0x80000100
284SYSCON2:	.word	0x80001100
285SYSCON3:	.word	0x80002200
286
287#define CLKCTL	       0x6  /* mask */
288#define CLKCTL_18      0x0  /* 18.432 MHz */
289#define CLKCTL_36      0x2  /* 36.864 MHz */
290#define CLKCTL_49      0x4  /* 49.152 MHz */
291#define CLKCTL_73      0x6  /* 73.728 MHz */
292
293#elif defined(CONFIG_LPC2292)
294PLLCFG_ADR:	.word	PLLCFG
295PLLFEED_ADR:	.word	PLLFEED
296PLLCON_ADR:	.word	PLLCON
297PLLSTAT_ADR:	.word	PLLSTAT
298VPBDIV_ADR:	.word	VPBDIV
299MEMMAP_ADR:	.word	MEMMAP
300
301#endif
302
303cpu_init_crit:
304#if defined(CONFIG_IMPA7) || defined(CONFIG_EP7312) || defined(CONFIG_ARMADILLO)
305
306	/*
307	 * mask all IRQs by clearing all bits in the INTMRs
308	 */
309	mov	r1, #0x00
310	ldr	r0, INTMR1
311	str	r1, [r0]
312	ldr	r0, INTMR2
313	str	r1, [r0]
314	ldr	r0, INTMR3
315	str	r1, [r0]
316
317	/*
318	 * flush v4 I/D caches
319	 */
320	mov	r0, #0
321	mcr	p15, 0, r0, c7, c7, 0	/* flush v3/v4 cache */
322	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
323
324	/*
325	 * disable MMU stuff and caches
326	 */
327	mrc	p15,0,r0,c1,c0
328	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
329	bic	r0, r0, #0x0000008f	@ clear bits 7, 3:0 (B--- WCAM)
330	orr	r0, r0, #0x00000002	@ set bit 2 (A) Align
331	mcr	p15,0,r0,c1,c0
332#elif defined(CONFIG_NETARM)
333	/*
334	 * prior to software reset : need to set pin PORTC4 to be *HRESET
335	 */
336	ldr	r0, =NETARM_GEN_MODULE_BASE
337	ldr	r1, =(NETARM_GEN_PORT_MODE(0x10) | \
338			NETARM_GEN_PORT_DIR(0x10))
339	str	r1, [r0, #+NETARM_GEN_PORTC]
340	/*
341	 * software reset : see HW Ref. Guide 8.2.4 : Software Service register
342	 *		    for an explanation of this process
343	 */
344	ldr	r0, =NETARM_GEN_MODULE_BASE
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	ldr	r1, =NETARM_GEN_SW_SVC_RESETA
350	str	r1, [r0, #+NETARM_GEN_SOFTWARE_SERVICE]
351	ldr	r1, =NETARM_GEN_SW_SVC_RESETB
352	str	r1, [r0, #+NETARM_GEN_SOFTWARE_SERVICE]
353	/*
354	 * setup PLL and System Config
355	 */
356	ldr	r0, =NETARM_GEN_MODULE_BASE
357
358	ldr	r1, =(	NETARM_GEN_SYS_CFG_LENDIAN | \
359			NETARM_GEN_SYS_CFG_BUSFULL | \
360			NETARM_GEN_SYS_CFG_USER_EN | \
361			NETARM_GEN_SYS_CFG_ALIGN_ABORT | \
362			NETARM_GEN_SYS_CFG_BUSARB_INT | \
363			NETARM_GEN_SYS_CFG_BUSMON_EN )
364
365	str	r1, [r0, #+NETARM_GEN_SYSTEM_CONTROL]
366
367#ifndef CONFIG_NETARM_PLL_BYPASS
368	ldr	r1, =(	NETARM_GEN_PLL_CTL_PLLCNT(NETARM_PLL_COUNT_VAL) | \
369			NETARM_GEN_PLL_CTL_POLTST_DEF | \
370			NETARM_GEN_PLL_CTL_INDIV(1) | \
371			NETARM_GEN_PLL_CTL_ICP_DEF | \
372			NETARM_GEN_PLL_CTL_OUTDIV(2) )
373	str	r1, [r0, #+NETARM_GEN_PLL_CONTROL]
374#endif
375
376	/*
377	 * mask all IRQs by clearing all bits in the INTMRs
378	 */
379	mov	r1, #0
380	ldr	r0, =NETARM_GEN_MODULE_BASE
381	str	r1, [r0, #+NETARM_GEN_INTR_ENABLE]
382
383#elif defined(CONFIG_S3C4510B)
384
385	/*
386	 * Mask off all IRQ sources
387	 */
388	ldr	r1, =REG_INTMASK
389	ldr	r0, =0x3FFFFF
390	str	r0, [r1]
391
392	/*
393	 * Disable Cache
394	 */
395	ldr r0, =REG_SYSCFG
396	ldr r1, =0x83ffffa0	/* cache-disabled  */
397	str r1, [r0]
398
399#elif defined(CONFIG_INTEGRATOR) && defined(CONFIG_ARCH_INTEGRATOR)
400	/* No specific initialisation for IntegratorAP/CM720T as yet */
401#elif defined(CONFIG_LPC2292)
402	/* Set-up PLL */
403	mov	r3, #0xAA
404	mov	r4, #0x55
405	/* First disconnect and disable the PLL */
406	ldr	r0, PLLCON_ADR
407	mov	r1, #0x00
408	str	r1, [r0]
409	ldr	r0, PLLFEED_ADR /* start feed sequence */
410	str	r3, [r0]
411	str	r4, [r0]	/* feed sequence done */
412	/* Set new M and P values */
413	ldr	r0, PLLCFG_ADR
414	mov	r1, #0x23	/* M=4 and P=2 */
415	str	r1, [r0]
416	ldr	r0, PLLFEED_ADR /* start feed sequence */
417	str	r3, [r0]
418	str	r4, [r0]	/* feed sequence done */
419	/* Then enable the PLL */
420	ldr	r0, PLLCON_ADR
421	mov	r1, #0x01	/* PLL enable bit */
422	str	r1, [r0]
423	ldr	r0, PLLFEED_ADR /* start feed sequence */
424	str	r3, [r0]
425	str	r4, [r0]	/* feed sequence done */
426	/* Wait for the lock */
427	ldr	r0, PLLSTAT_ADR
428	mov	r1, #0x400	/* lock bit */
429lock_loop:
430	ldr	r2, [r0]
431	and	r2, r1, r2
432	cmp	r2, #0
433	beq	lock_loop
434	/* And finally connect the PLL */
435	ldr	r0, PLLCON_ADR
436	mov	r1, #0x03	/* PLL enable bit and connect bit */
437	str	r1, [r0]
438	ldr	r0, PLLFEED_ADR /* start feed sequence */
439	str	r3, [r0]
440	str	r4, [r0]	/* feed sequence done */
441	/* Set-up VPBDIV register */
442	ldr	r0, VPBDIV_ADR
443	mov	r1, #0x01	/* VPB clock is same as process clock */
444	str	r1, [r0]
445#else
446#error No cpu_init_crit() defined for current CPU type
447#endif
448
449#ifdef CONFIG_ARM7_REVD
450	/* set clock speed */
451	/* !!! we run @ 36 MHz due to a hardware flaw in Rev. D processors */
452	/* !!! not doing DRAM refresh properly! */
453	ldr	r0, SYSCON3
454	ldr	r1, [r0]
455	bic	r1, r1, #CLKCTL
456	orr	r1, r1, #CLKCTL_36
457	str	r1, [r0]
458#endif
459
460#ifndef CONFIG_LPC2292
461	mov	ip, lr
462	/*
463	 * before relocating, we have to setup RAM timing
464	 * because memory timing is board-dependent, you will
465	 * find a lowlevel_init.S in your board directory.
466	 */
467	bl	lowlevel_init
468	mov	lr, ip
469#endif
470
471	mov	pc, lr
472
473
474/*
475 *************************************************************************
476 *
477 * Interrupt handling
478 *
479 *************************************************************************
480 */
481
482@
483@ IRQ stack frame.
484@
485#define S_FRAME_SIZE	72
486
487#define S_OLD_R0	68
488#define S_PSR		64
489#define S_PC		60
490#define S_LR		56
491#define S_SP		52
492
493#define S_IP		48
494#define S_FP		44
495#define S_R10		40
496#define S_R9		36
497#define S_R8		32
498#define S_R7		28
499#define S_R6		24
500#define S_R5		20
501#define S_R4		16
502#define S_R3		12
503#define S_R2		8
504#define S_R1		4
505#define S_R0		0
506
507#define MODE_SVC 0x13
508#define I_BIT	 0x80
509
510/*
511 * use bad_save_user_regs for abort/prefetch/undef/swi ...
512 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
513 */
514
515	.macro	bad_save_user_regs
516	sub	sp, sp, #S_FRAME_SIZE
517	stmia	sp, {r0 - r12}			@ Calling r0-r12
518	add	r8, sp, #S_PC
519
520	ldr	r2, IRQ_STACK_START_IN
521	ldmia	r2, {r2 - r4}			@ get pc, cpsr, old_r0
522	add	r0, sp, #S_FRAME_SIZE		@ restore sp_SVC
523
524	add	r5, sp, #S_SP
525	mov	r1, lr
526	stmia	r5, {r0 - r4}			@ save sp_SVC, lr_SVC, pc, cpsr, old_r
527	mov	r0, sp
528	.endm
529
530	.macro	irq_save_user_regs
531	sub	sp, sp, #S_FRAME_SIZE
532	stmia	sp, {r0 - r12}			@ Calling r0-r12
533	add	r8, sp, #S_PC
534	stmdb	r8, {sp, lr}^			@ Calling SP, LR
535	str	lr, [r8, #0]			@ Save calling PC
536	mrs	r6, spsr
537	str	r6, [r8, #4]			@ Save CPSR
538	str	r0, [r8, #8]			@ Save OLD_R0
539	mov	r0, sp
540	.endm
541
542	.macro	irq_restore_user_regs
543	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
544	mov	r0, r0
545	ldr	lr, [sp, #S_PC]			@ Get PC
546	add	sp, sp, #S_FRAME_SIZE
547	subs	pc, lr, #4			@ return & move spsr_svc into cpsr
548	.endm
549
550	.macro get_bad_stack
551	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
552
553	str	lr, [r13]			@ save caller lr / spsr
554	mrs	lr, spsr
555	str	lr, [r13, #4]
556
557	mov	r13, #MODE_SVC			@ prepare SVC-Mode
558	msr	spsr_c, r13
559	mov	lr, pc
560	movs	pc, lr
561	.endm
562
563	.macro get_irq_stack			@ setup IRQ stack
564	ldr	sp, IRQ_STACK_START
565	.endm
566
567	.macro get_fiq_stack			@ setup FIQ stack
568	ldr	sp, FIQ_STACK_START
569	.endm
570
571/*
572 * exception handlers
573 */
574	.align	5
575undefined_instruction:
576	get_bad_stack
577	bad_save_user_regs
578	bl	do_undefined_instruction
579
580	.align	5
581software_interrupt:
582	get_bad_stack
583	bad_save_user_regs
584	bl	do_software_interrupt
585
586	.align	5
587prefetch_abort:
588	get_bad_stack
589	bad_save_user_regs
590	bl	do_prefetch_abort
591
592	.align	5
593data_abort:
594	get_bad_stack
595	bad_save_user_regs
596	bl	do_data_abort
597
598	.align	5
599not_used:
600	get_bad_stack
601	bad_save_user_regs
602	bl	do_not_used
603
604#ifdef CONFIG_USE_IRQ
605
606	.align	5
607irq:
608	get_irq_stack
609	irq_save_user_regs
610	bl	do_irq
611	irq_restore_user_regs
612
613	.align	5
614fiq:
615	get_fiq_stack
616	/* someone ought to write a more effiction fiq_save_user_regs */
617	irq_save_user_regs
618	bl	do_fiq
619	irq_restore_user_regs
620
621#else
622
623	.align	5
624irq:
625	get_bad_stack
626	bad_save_user_regs
627	bl	do_irq
628
629	.align	5
630fiq:
631	get_bad_stack
632	bad_save_user_regs
633	bl	do_fiq
634
635#endif
636
637#if defined(CONFIG_IMPA7) || defined(CONFIG_EP7312) || defined(CONFIG_ARMADILLO)
638	.align	5
639.globl reset_cpu
640reset_cpu:
641	mov	ip, #0
642	mcr	p15, 0, ip, c7, c7, 0		@ invalidate cache
643	mcr	p15, 0, ip, c8, c7, 0		@ flush TLB (v4)
644	mrc	p15, 0, ip, c1, c0, 0		@ get ctrl register
645	bic	ip, ip, #0x000f			@ ............wcam
646	bic	ip, ip, #0x2100			@ ..v....s........
647	mcr	p15, 0, ip, c1, c0, 0		@ ctrl register
648	mov	pc, r0
649#elif defined(CONFIG_NETARM)
650	.align	5
651.globl reset_cpu
652reset_cpu:
653	ldr	r1, =NETARM_MEM_MODULE_BASE
654	ldr	r0, [r1, #+NETARM_MEM_CS0_BASE_ADDR]
655	ldr	r1, =0xFFFFF000
656	and	r0, r1, r0
657	ldr	r1, =(relocate-CONFIG_SYS_TEXT_BASE)
658	add	r0, r1, r0
659	ldr	r4, =NETARM_GEN_MODULE_BASE
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	ldr	r1, =NETARM_GEN_SW_SVC_RESETA
665	str	r1, [r4, #+NETARM_GEN_SOFTWARE_SERVICE]
666	ldr	r1, =NETARM_GEN_SW_SVC_RESETB
667	str	r1, [r4, #+NETARM_GEN_SOFTWARE_SERVICE]
668	mov	pc, r0
669#elif defined(CONFIG_S3C4510B)
670/* Nothing done here as reseting the CPU is board specific, depending
671 * on external peripherals such as watchdog timers, etc. */
672#elif defined(CONFIG_INTEGRATOR) && defined(CONFIG_ARCH_INTEGRATOR)
673	/* No specific reset actions for IntegratorAP/CM720T as yet */
674#elif defined(CONFIG_LPC2292)
675	.align	5
676.globl reset_cpu
677reset_cpu:
678	mov	pc, r0
679#else
680#error No reset_cpu() defined for current CPU type
681#endif
682