xref: /rk3399_rockchip-uboot/arch/arm/cpu/arm720t/start.S (revision c7da6c6757aa17bb6130833b0e1e7e2a068ea2f6)
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#ifdef CONFIG_SPL_BUILD
55_undefined_instruction: .word _undefined_instruction
56_software_interrupt:	.word _software_interrupt
57_prefetch_abort:	.word _prefetch_abort
58_data_abort:		.word _data_abort
59_not_used:		.word _not_used
60_irq:			.word _irq
61_fiq:			.word _fiq
62#else
63_undefined_instruction: .word undefined_instruction
64_software_interrupt:	.word software_interrupt
65_prefetch_abort:	.word prefetch_abort
66_data_abort:		.word data_abort
67_not_used:		.word not_used
68_irq:			.word irq
69_fiq:			.word fiq
70#endif	/* CONFIG_SPL_BUILD */
71
72	.balignl 16,0xdeadbeef
73
74
75/*
76 *************************************************************************
77 *
78 * Startup Code (reset vector)
79 *
80 * do important init only if we don't start from RAM!
81 * relocate armboot to ram
82 * setup stack
83 * jump to second stage
84 *
85 *************************************************************************
86 */
87
88.globl _TEXT_BASE
89_TEXT_BASE:
90	.word	CONFIG_SYS_TEXT_BASE
91
92/*
93 * These are defined in the board-specific linker script.
94 * Subtracting _start from them lets the linker put their
95 * relative position in the executable instead of leaving
96 * them null.
97 */
98.globl _bss_start_ofs
99_bss_start_ofs:
100	.word __bss_start - _start
101
102.globl _bss_end_ofs
103_bss_end_ofs:
104	.word __bss_end__ - _start
105
106.globl _end_ofs
107_end_ofs:
108	.word _end - _start
109
110#ifdef CONFIG_USE_IRQ
111/* IRQ stack memory (calculated at run-time) */
112.globl IRQ_STACK_START
113IRQ_STACK_START:
114	.word	0x0badc0de
115
116/* IRQ stack memory (calculated at run-time) */
117.globl FIQ_STACK_START
118FIQ_STACK_START:
119	.word 0x0badc0de
120#endif
121
122/* IRQ stack memory (calculated at run-time) + 8 bytes */
123.globl IRQ_STACK_START_IN
124IRQ_STACK_START_IN:
125	.word	0x0badc0de
126
127/*
128 * the actual reset code
129 */
130
131reset:
132	/*
133	 * set the cpu to SVC32 mode
134	 */
135	mrs	r0,cpsr
136	bic	r0,r0,#0x1f
137	orr	r0,r0,#0xd3
138	msr	cpsr,r0
139
140	/*
141	 * we do sys-critical inits only at reboot,
142	 * not when booting from ram!
143	 */
144#ifndef CONFIG_SKIP_LOWLEVEL_INIT
145	bl	cpu_init_crit
146#endif
147
148#ifdef CONFIG_LPC2292
149	bl	lowlevel_init
150#endif
151
152/* Set stackpointer in internal RAM to call board_init_f */
153call_board_init_f:
154	ldr	sp, =(CONFIG_SYS_INIT_SP_ADDR)
155	bic	sp, sp, #7 /* 8-byte alignment for ABI compliance */
156	ldr	r0,=0x00000000
157	bl	board_init_f
158
159/*------------------------------------------------------------------------------*/
160
161/*
162 * void relocate_code (addr_sp, gd, addr_moni)
163 *
164 * This "function" does not return, instead it continues in RAM
165 * after relocating the monitor code.
166 *
167 */
168	.globl	relocate_code
169relocate_code:
170	mov	r4, r0	/* save addr_sp */
171	mov	r5, r1	/* save addr of gd */
172	mov	r6, r2	/* save addr of destination */
173
174	/* Set up the stack						    */
175stack_setup:
176	mov	sp, r4
177
178	adr	r0, _start
179	cmp	r0, r6
180	moveq	r9, #0		/* no relocation. relocation offset(r9) = 0 */
181	beq	clear_bss		/* skip relocation */
182	mov	r1, r6			/* r1 <- scratch for copy_loop */
183	ldr	r3, _bss_start_ofs
184	add	r2, r0, r3		/* r2 <- source end address	    */
185
186copy_loop:
187	ldmia	r0!, {r9-r10}		/* copy from source address [r0]    */
188	stmia	r1!, {r9-r10}		/* copy to   target address [r1]    */
189	cmp	r0, r2			/* until source end address [r2]    */
190	blo	copy_loop
191
192#ifndef CONFIG_SPL_BUILD
193	/*
194	 * fix .rel.dyn relocations
195	 */
196	ldr	r0, _TEXT_BASE		/* r0 <- Text base */
197	sub	r9, r6, r0		/* r9 <- relocation offset */
198	ldr	r10, _dynsym_start_ofs	/* r10 <- sym table ofs */
199	add	r10, r10, r0		/* r10 <- sym table in FLASH */
200	ldr	r2, _rel_dyn_start_ofs	/* r2 <- rel dyn start ofs */
201	add	r2, r2, r0		/* r2 <- rel dyn start in FLASH */
202	ldr	r3, _rel_dyn_end_ofs	/* r3 <- rel dyn end ofs */
203	add	r3, r3, r0		/* r3 <- rel dyn end in FLASH */
204fixloop:
205	ldr	r0, [r2]		/* r0 <- location to fix up, IN FLASH! */
206	add	r0, r0, r9		/* r0 <- location to fix up in RAM */
207	ldr	r1, [r2, #4]
208	and	r7, r1, #0xff
209	cmp	r7, #23			/* relative fixup? */
210	beq	fixrel
211	cmp	r7, #2			/* absolute fixup? */
212	beq	fixabs
213	/* ignore unknown type of fixup */
214	b	fixnext
215fixabs:
216	/* absolute fix: set location to (offset) symbol value */
217	mov	r1, r1, LSR #4		/* r1 <- symbol index in .dynsym */
218	add	r1, r10, r1		/* r1 <- address of symbol in table */
219	ldr	r1, [r1, #4]		/* r1 <- symbol value */
220	add	r1, r1, r9		/* r1 <- relocated sym addr */
221	b	fixnext
222fixrel:
223	/* relative fix: increase location by offset */
224	ldr	r1, [r0]
225	add	r1, r1, r9
226fixnext:
227	str	r1, [r0]
228	add	r2, r2, #8		/* each rel.dyn entry is 8 bytes */
229	cmp	r2, r3
230	blo	fixloop
231#endif
232
233clear_bss:
234#ifndef CONFIG_SPL_BUILD
235	ldr	r0, _bss_start_ofs
236	ldr	r1, _bss_end_ofs
237	mov	r4, r6			/* reloc addr */
238	add	r0, r0, r4
239	add	r1, r1, r4
240	mov	r2, #0x00000000		/* clear			    */
241
242clbss_l:cmp	r0, r1			/* clear loop... */
243	bhs	clbss_e			/* if reached end of bss, exit */
244	str	r2, [r0]
245	add	r0, r0, #4
246	b	clbss_l
247clbss_e:
248
249	bl coloured_LED_init
250	bl red_led_on
251#endif
252
253/*
254 * We are done. Do not return, instead branch to second part of board
255 * initialization, now running from RAM.
256 */
257	ldr	r0, _board_init_r_ofs
258	adr	r1, _start
259	add	lr, r0, r1
260	add	lr, lr, r9
261	/* setup parameters for board_init_r */
262	mov	r0, r5		/* gd_t */
263	mov	r1, r6		/* dest_addr */
264	/* jump to it ... */
265	mov	pc, lr
266
267_board_init_r_ofs:
268	.word board_init_r - _start
269
270_rel_dyn_start_ofs:
271	.word __rel_dyn_start - _start
272_rel_dyn_end_ofs:
273	.word __rel_dyn_end - _start
274_dynsym_start_ofs:
275	.word __dynsym_start - _start
276
277/*
278 *************************************************************************
279 *
280 * CPU_init_critical registers
281 *
282 * setup important registers
283 * setup memory timing
284 *
285 *************************************************************************
286 */
287
288#if defined(CONFIG_LPC2292)
289PLLCFG_ADR:	.word	PLLCFG
290PLLFEED_ADR:	.word	PLLFEED
291PLLCON_ADR:	.word	PLLCON
292PLLSTAT_ADR:	.word	PLLSTAT
293VPBDIV_ADR:	.word	VPBDIV
294MEMMAP_ADR:	.word	MEMMAP
295
296#endif
297
298cpu_init_crit:
299#if defined(CONFIG_NETARM)
300	/*
301	 * prior to software reset : need to set pin PORTC4 to be *HRESET
302	 */
303	ldr	r0, =NETARM_GEN_MODULE_BASE
304	ldr	r1, =(NETARM_GEN_PORT_MODE(0x10) | \
305			NETARM_GEN_PORT_DIR(0x10))
306	str	r1, [r0, #+NETARM_GEN_PORTC]
307	/*
308	 * software reset : see HW Ref. Guide 8.2.4 : Software Service register
309	 *		    for an explanation of this process
310	 */
311	ldr	r0, =NETARM_GEN_MODULE_BASE
312	ldr	r1, =NETARM_GEN_SW_SVC_RESETA
313	str	r1, [r0, #+NETARM_GEN_SOFTWARE_SERVICE]
314	ldr	r1, =NETARM_GEN_SW_SVC_RESETB
315	str	r1, [r0, #+NETARM_GEN_SOFTWARE_SERVICE]
316	ldr	r1, =NETARM_GEN_SW_SVC_RESETA
317	str	r1, [r0, #+NETARM_GEN_SOFTWARE_SERVICE]
318	ldr	r1, =NETARM_GEN_SW_SVC_RESETB
319	str	r1, [r0, #+NETARM_GEN_SOFTWARE_SERVICE]
320	/*
321	 * setup PLL and System Config
322	 */
323	ldr	r0, =NETARM_GEN_MODULE_BASE
324
325	ldr	r1, =(	NETARM_GEN_SYS_CFG_LENDIAN | \
326			NETARM_GEN_SYS_CFG_BUSFULL | \
327			NETARM_GEN_SYS_CFG_USER_EN | \
328			NETARM_GEN_SYS_CFG_ALIGN_ABORT | \
329			NETARM_GEN_SYS_CFG_BUSARB_INT | \
330			NETARM_GEN_SYS_CFG_BUSMON_EN )
331
332	str	r1, [r0, #+NETARM_GEN_SYSTEM_CONTROL]
333
334#ifndef CONFIG_NETARM_PLL_BYPASS
335	ldr	r1, =(	NETARM_GEN_PLL_CTL_PLLCNT(NETARM_PLL_COUNT_VAL) | \
336			NETARM_GEN_PLL_CTL_POLTST_DEF | \
337			NETARM_GEN_PLL_CTL_INDIV(1) | \
338			NETARM_GEN_PLL_CTL_ICP_DEF | \
339			NETARM_GEN_PLL_CTL_OUTDIV(2) )
340	str	r1, [r0, #+NETARM_GEN_PLL_CONTROL]
341#endif
342
343	/*
344	 * mask all IRQs by clearing all bits in the INTMRs
345	 */
346	mov	r1, #0
347	ldr	r0, =NETARM_GEN_MODULE_BASE
348	str	r1, [r0, #+NETARM_GEN_INTR_ENABLE]
349
350#elif defined(CONFIG_S3C4510B)
351
352	/*
353	 * Mask off all IRQ sources
354	 */
355	ldr	r1, =REG_INTMASK
356	ldr	r0, =0x3FFFFF
357	str	r0, [r1]
358
359	/*
360	 * Disable Cache
361	 */
362	ldr r0, =REG_SYSCFG
363	ldr r1, =0x83ffffa0	/* cache-disabled  */
364	str r1, [r0]
365
366#elif defined(CONFIG_INTEGRATOR) && defined(CONFIG_ARCH_INTEGRATOR)
367	/* No specific initialisation for IntegratorAP/CM720T as yet */
368#elif defined(CONFIG_LPC2292)
369	/* Set-up PLL */
370	mov	r3, #0xAA
371	mov	r4, #0x55
372	/* First disconnect and disable the PLL */
373	ldr	r0, PLLCON_ADR
374	mov	r1, #0x00
375	str	r1, [r0]
376	ldr	r0, PLLFEED_ADR /* start feed sequence */
377	str	r3, [r0]
378	str	r4, [r0]	/* feed sequence done */
379	/* Set new M and P values */
380	ldr	r0, PLLCFG_ADR
381	mov	r1, #0x23	/* M=4 and P=2 */
382	str	r1, [r0]
383	ldr	r0, PLLFEED_ADR /* start feed sequence */
384	str	r3, [r0]
385	str	r4, [r0]	/* feed sequence done */
386	/* Then enable the PLL */
387	ldr	r0, PLLCON_ADR
388	mov	r1, #0x01	/* PLL enable bit */
389	str	r1, [r0]
390	ldr	r0, PLLFEED_ADR /* start feed sequence */
391	str	r3, [r0]
392	str	r4, [r0]	/* feed sequence done */
393	/* Wait for the lock */
394	ldr	r0, PLLSTAT_ADR
395	mov	r1, #0x400	/* lock bit */
396lock_loop:
397	ldr	r2, [r0]
398	and	r2, r1, r2
399	cmp	r2, #0
400	beq	lock_loop
401	/* And finally connect the PLL */
402	ldr	r0, PLLCON_ADR
403	mov	r1, #0x03	/* PLL enable bit and connect bit */
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-up VPBDIV register */
409	ldr	r0, VPBDIV_ADR
410	mov	r1, #0x01	/* VPB clock is same as process clock */
411	str	r1, [r0]
412#else
413#error No cpu_init_crit() defined for current CPU type
414#endif
415
416#ifdef CONFIG_ARM7_REVD
417	/* set clock speed */
418	/* !!! we run @ 36 MHz due to a hardware flaw in Rev. D processors */
419	/* !!! not doing DRAM refresh properly! */
420	ldr	r0, SYSCON3
421	ldr	r1, [r0]
422	bic	r1, r1, #CLKCTL
423	orr	r1, r1, #CLKCTL_36
424	str	r1, [r0]
425#endif
426
427#ifndef CONFIG_LPC2292
428	mov	ip, lr
429	/*
430	 * before relocating, we have to setup RAM timing
431	 * because memory timing is board-dependent, you will
432	 * find a lowlevel_init.S in your board directory.
433	 */
434	bl	lowlevel_init
435	mov	lr, ip
436#endif
437
438	mov	pc, lr
439
440
441#ifndef CONFIG_SPL_BUILD
442/*
443 *************************************************************************
444 *
445 * Interrupt handling
446 *
447 *************************************************************************
448 */
449
450@
451@ IRQ stack frame.
452@
453#define S_FRAME_SIZE	72
454
455#define S_OLD_R0	68
456#define S_PSR		64
457#define S_PC		60
458#define S_LR		56
459#define S_SP		52
460
461#define S_IP		48
462#define S_FP		44
463#define S_R10		40
464#define S_R9		36
465#define S_R8		32
466#define S_R7		28
467#define S_R6		24
468#define S_R5		20
469#define S_R4		16
470#define S_R3		12
471#define S_R2		8
472#define S_R1		4
473#define S_R0		0
474
475#define MODE_SVC 0x13
476#define I_BIT	 0x80
477
478/*
479 * use bad_save_user_regs for abort/prefetch/undef/swi ...
480 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
481 */
482
483	.macro	bad_save_user_regs
484	sub	sp, sp, #S_FRAME_SIZE
485	stmia	sp, {r0 - r12}			@ Calling r0-r12
486	add	r8, sp, #S_PC
487
488	ldr	r2, IRQ_STACK_START_IN
489	ldmia	r2, {r2 - r4}			@ get pc, cpsr, old_r0
490	add	r0, sp, #S_FRAME_SIZE		@ restore sp_SVC
491
492	add	r5, sp, #S_SP
493	mov	r1, lr
494	stmia	r5, {r0 - r4}			@ save sp_SVC, lr_SVC, pc, cpsr, old_r
495	mov	r0, sp
496	.endm
497
498	.macro	irq_save_user_regs
499	sub	sp, sp, #S_FRAME_SIZE
500	stmia	sp, {r0 - r12}			@ Calling r0-r12
501	add	r8, sp, #S_PC
502	stmdb	r8, {sp, lr}^			@ Calling SP, LR
503	str	lr, [r8, #0]			@ Save calling PC
504	mrs	r6, spsr
505	str	r6, [r8, #4]			@ Save CPSR
506	str	r0, [r8, #8]			@ Save OLD_R0
507	mov	r0, sp
508	.endm
509
510	.macro	irq_restore_user_regs
511	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
512	mov	r0, r0
513	ldr	lr, [sp, #S_PC]			@ Get PC
514	add	sp, sp, #S_FRAME_SIZE
515	subs	pc, lr, #4			@ return & move spsr_svc into cpsr
516	.endm
517
518	.macro get_bad_stack
519	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
520
521	str	lr, [r13]			@ save caller lr / spsr
522	mrs	lr, spsr
523	str	lr, [r13, #4]
524
525	mov	r13, #MODE_SVC			@ prepare SVC-Mode
526	msr	spsr_c, r13
527	mov	lr, pc
528	movs	pc, lr
529	.endm
530
531	.macro get_irq_stack			@ setup IRQ stack
532	ldr	sp, IRQ_STACK_START
533	.endm
534
535	.macro get_fiq_stack			@ setup FIQ stack
536	ldr	sp, FIQ_STACK_START
537	.endm
538
539/*
540 * exception handlers
541 */
542	.align	5
543undefined_instruction:
544	get_bad_stack
545	bad_save_user_regs
546	bl	do_undefined_instruction
547
548	.align	5
549software_interrupt:
550	get_bad_stack
551	bad_save_user_regs
552	bl	do_software_interrupt
553
554	.align	5
555prefetch_abort:
556	get_bad_stack
557	bad_save_user_regs
558	bl	do_prefetch_abort
559
560	.align	5
561data_abort:
562	get_bad_stack
563	bad_save_user_regs
564	bl	do_data_abort
565
566	.align	5
567not_used:
568	get_bad_stack
569	bad_save_user_regs
570	bl	do_not_used
571
572#ifdef CONFIG_USE_IRQ
573
574	.align	5
575irq:
576	get_irq_stack
577	irq_save_user_regs
578	bl	do_irq
579	irq_restore_user_regs
580
581	.align	5
582fiq:
583	get_fiq_stack
584	/* someone ought to write a more effiction fiq_save_user_regs */
585	irq_save_user_regs
586	bl	do_fiq
587	irq_restore_user_regs
588
589#else
590
591	.align	5
592irq:
593	get_bad_stack
594	bad_save_user_regs
595	bl	do_irq
596
597	.align	5
598fiq:
599	get_bad_stack
600	bad_save_user_regs
601	bl	do_fiq
602
603#endif
604#endif /* CONFIG_SPL_BUILD */
605
606#if defined(CONFIG_NETARM)
607	.align	5
608.globl reset_cpu
609reset_cpu:
610	ldr	r1, =NETARM_MEM_MODULE_BASE
611	ldr	r0, [r1, #+NETARM_MEM_CS0_BASE_ADDR]
612	ldr	r1, =0xFFFFF000
613	and	r0, r1, r0
614	ldr	r1, =(relocate-CONFIG_SYS_TEXT_BASE)
615	add	r0, r1, r0
616	ldr	r4, =NETARM_GEN_MODULE_BASE
617	ldr	r1, =NETARM_GEN_SW_SVC_RESETA
618	str	r1, [r4, #+NETARM_GEN_SOFTWARE_SERVICE]
619	ldr	r1, =NETARM_GEN_SW_SVC_RESETB
620	str	r1, [r4, #+NETARM_GEN_SOFTWARE_SERVICE]
621	ldr	r1, =NETARM_GEN_SW_SVC_RESETA
622	str	r1, [r4, #+NETARM_GEN_SOFTWARE_SERVICE]
623	ldr	r1, =NETARM_GEN_SW_SVC_RESETB
624	str	r1, [r4, #+NETARM_GEN_SOFTWARE_SERVICE]
625	mov	pc, r0
626#elif defined(CONFIG_S3C4510B)
627/* Nothing done here as reseting the CPU is board specific, depending
628 * on external peripherals such as watchdog timers, etc. */
629#elif defined(CONFIG_INTEGRATOR) && defined(CONFIG_ARCH_INTEGRATOR)
630	/* No specific reset actions for IntegratorAP/CM720T as yet */
631#elif defined(CONFIG_LPC2292)
632	.align	5
633.globl reset_cpu
634reset_cpu:
635	mov	pc, r0
636#else
637#error No reset_cpu() defined for current CPU type
638#endif
639