xref: /rk3399_rockchip-uboot/arch/arm/cpu/armv7/start.S (revision 959eaa74b83e4d18be5829a5a7c8deaa11aac7e0)
1/*
2 * armboot - Startup Code for OMAP3530/ARM Cortex CPU-core
3 *
4 * Copyright (c) 2004	Texas Instruments <r-woodruff2@ti.com>
5 *
6 * Copyright (c) 2001	Marius Gröger <mag@sysgo.de>
7 * Copyright (c) 2002	Alex Züpke <azu@sysgo.de>
8 * Copyright (c) 2002	Gary Jennejohn <garyj@denx.de>
9 * Copyright (c) 2003	Richard Woodruff <r-woodruff2@ti.com>
10 * Copyright (c) 2003	Kshitij <kshitij@ti.com>
11 * Copyright (c) 2006-2008 Syed Mohammed Khasim <x0khasim@ti.com>
12 *
13 * See file CREDITS for list of people who contributed to this
14 * project.
15 *
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License as
18 * published by the Free Software Foundation; either version 2 of
19 * the License, or (at your option) any later version.
20 *
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
24 * GNU General Public License for more details.
25 *
26 * You should have received a copy of the GNU General Public License
27 * along with this program; if not, write to the Free Software
28 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
29 * MA 02111-1307 USA
30 */
31
32#include <asm-offsets.h>
33#include <config.h>
34#include <version.h>
35#include <asm/system.h>
36#include <linux/linkage.h>
37
38.globl _start
39_start: b	reset
40	ldr	pc, _undefined_instruction
41	ldr	pc, _software_interrupt
42	ldr	pc, _prefetch_abort
43	ldr	pc, _data_abort
44	ldr	pc, _not_used
45	ldr	pc, _irq
46	ldr	pc, _fiq
47#ifdef CONFIG_SPL_BUILD
48_undefined_instruction: .word _undefined_instruction
49_software_interrupt:	.word _software_interrupt
50_prefetch_abort:	.word _prefetch_abort
51_data_abort:		.word _data_abort
52_not_used:		.word _not_used
53_irq:			.word _irq
54_fiq:			.word _fiq
55_pad:			.word 0x12345678 /* now 16*4=64 */
56#else
57_undefined_instruction: .word undefined_instruction
58_software_interrupt:	.word software_interrupt
59_prefetch_abort:	.word prefetch_abort
60_data_abort:		.word data_abort
61_not_used:		.word not_used
62_irq:			.word irq
63_fiq:			.word fiq
64_pad:			.word 0x12345678 /* now 16*4=64 */
65#endif	/* CONFIG_SPL_BUILD */
66
67.global _end_vect
68_end_vect:
69
70	.balignl 16,0xdeadbeef
71/*************************************************************************
72 *
73 * Startup Code (reset vector)
74 *
75 * do important init only if we don't start from memory!
76 * setup Memory and board specific bits prior to relocation.
77 * relocate armboot to ram
78 * setup stack
79 *
80 *************************************************************************/
81
82.globl _TEXT_BASE
83_TEXT_BASE:
84#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_TEXT_BASE)
85	.word	CONFIG_SPL_TEXT_BASE
86#else
87	.word	CONFIG_SYS_TEXT_BASE
88#endif
89
90/*
91 * These are defined in the board-specific linker script.
92 */
93.globl _bss_start_ofs
94_bss_start_ofs:
95	.word __bss_start - _start
96
97.global	_image_copy_end_ofs
98_image_copy_end_ofs:
99	.word 	__image_copy_end - _start
100
101.globl _bss_end_ofs
102_bss_end_ofs:
103	.word __bss_end - _start
104
105.globl _end_ofs
106_end_ofs:
107	.word _end - _start
108
109#ifdef CONFIG_USE_IRQ
110/* IRQ stack memory (calculated at run-time) */
111.globl IRQ_STACK_START
112IRQ_STACK_START:
113	.word	0x0badc0de
114
115/* IRQ stack memory (calculated at run-time) */
116.globl FIQ_STACK_START
117FIQ_STACK_START:
118	.word 0x0badc0de
119#endif
120
121/* IRQ stack memory (calculated at run-time) + 8 bytes */
122.globl IRQ_STACK_START_IN
123IRQ_STACK_START_IN:
124	.word	0x0badc0de
125
126/*
127 * the actual reset code
128 */
129
130reset:
131	bl	save_boot_params
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 * Setup vector:
142 * (OMAP4 spl TEXT_BASE is not 32 byte aligned.
143 * Continue to use ROM code vector only in OMAP4 spl)
144 */
145#if !(defined(CONFIG_OMAP44XX) && defined(CONFIG_SPL_BUILD))
146	/* Set V=0 in CP15 SCTRL register - for VBAR to point to vector */
147	mrc	p15, 0, r0, c1, c0, 0	@ Read CP15 SCTRL Register
148	bic	r0, #CR_V		@ V = 0
149	mcr	p15, 0, r0, c1, c0, 0	@ Write CP15 SCTRL Register
150
151	/* Set vector address in CP15 VBAR register */
152	ldr	r0, =_start
153	mcr	p15, 0, r0, c12, c0, 0	@Set VBAR
154#endif
155
156	/* the mask ROM code should have PLL and others stable */
157#ifndef CONFIG_SKIP_LOWLEVEL_INIT
158	bl	cpu_init_cp15
159	bl	cpu_init_crit
160#endif
161
162	bl	_main
163
164/*------------------------------------------------------------------------------*/
165
166#ifndef CONFIG_SPL_BUILD
167/*
168 * void relocate_code (addr_sp, gd, addr_moni)
169 *
170 * This function relocates the monitor code.
171 */
172ENTRY(relocate_code)
173	mov	r4, r0	/* save addr_sp */
174	mov	r5, r1	/* save addr of gd */
175	mov	r6, r2	/* save addr of destination */
176
177	adr	r0, _start
178	cmp	r0, r6
179	moveq	r9, #0		/* no relocation. relocation offset(r9) = 0 */
180	beq	relocate_done		/* skip relocation */
181	mov	r1, r6			/* r1 <- scratch for copy_loop */
182	ldr	r3, _image_copy_end_ofs
183	add	r2, r0, r3		/* r2 <- source end address	    */
184
185copy_loop:
186	ldmia	r0!, {r9-r10}		/* copy from source address [r0]    */
187	stmia	r1!, {r9-r10}		/* copy to   target address [r1]    */
188	cmp	r0, r2			/* until source end address [r2]    */
189	blo	copy_loop
190
191	/*
192	 * fix .rel.dyn relocations
193	 */
194	ldr	r0, _TEXT_BASE		/* r0 <- Text base */
195	sub	r9, r6, r0		/* r9 <- relocation offset */
196	ldr	r10, _dynsym_start_ofs	/* r10 <- sym table ofs */
197	add	r10, r10, r0		/* r10 <- sym table in FLASH */
198	ldr	r2, _rel_dyn_start_ofs	/* r2 <- rel dyn start ofs */
199	add	r2, r2, r0		/* r2 <- rel dyn start in FLASH */
200	ldr	r3, _rel_dyn_end_ofs	/* r3 <- rel dyn end ofs */
201	add	r3, r3, r0		/* r3 <- rel dyn end in FLASH */
202fixloop:
203	ldr	r0, [r2]		/* r0 <- location to fix up, IN FLASH! */
204	add	r0, r0, r9		/* r0 <- location to fix up in RAM */
205	ldr	r1, [r2, #4]
206	and	r7, r1, #0xff
207	cmp	r7, #23			/* relative fixup? */
208	beq	fixrel
209	cmp	r7, #2			/* absolute fixup? */
210	beq	fixabs
211	/* ignore unknown type of fixup */
212	b	fixnext
213fixabs:
214	/* absolute fix: set location to (offset) symbol value */
215	mov	r1, r1, LSR #4		/* r1 <- symbol index in .dynsym */
216	add	r1, r10, r1		/* r1 <- address of symbol in table */
217	ldr	r1, [r1, #4]		/* r1 <- symbol value */
218	add	r1, r1, r9		/* r1 <- relocated sym addr */
219	b	fixnext
220fixrel:
221	/* relative fix: increase location by offset */
222	ldr	r1, [r0]
223	add	r1, r1, r9
224fixnext:
225	str	r1, [r0]
226	add	r2, r2, #8		/* each rel.dyn entry is 8 bytes */
227	cmp	r2, r3
228	blo	fixloop
229
230relocate_done:
231
232	bx	lr
233
234_rel_dyn_start_ofs:
235	.word __rel_dyn_start - _start
236_rel_dyn_end_ofs:
237	.word __rel_dyn_end - _start
238_dynsym_start_ofs:
239	.word __dynsym_start - _start
240ENDPROC(relocate_code)
241
242#endif
243
244ENTRY(c_runtime_cpu_setup)
245/*
246 * If I-cache is enabled invalidate it
247 */
248#ifndef CONFIG_SYS_ICACHE_OFF
249	mcr	p15, 0, r0, c7, c5, 0	@ invalidate icache
250	mcr     p15, 0, r0, c7, c10, 4	@ DSB
251	mcr     p15, 0, r0, c7, c5, 4	@ ISB
252#endif
253/*
254 * Move vector table
255 */
256#if !defined(CONFIG_TEGRA)
257	/* Set vector address in CP15 VBAR register */
258	ldr     r0, =_start
259	mcr     p15, 0, r0, c12, c0, 0  @Set VBAR
260#endif /* !Tegra */
261
262	bx	lr
263
264ENDPROC(c_runtime_cpu_setup)
265
266/*************************************************************************
267 *
268 * void save_boot_params(u32 r0, u32 r1, u32 r2, u32 r3)
269 *	__attribute__((weak));
270 *
271 * Stack pointer is not yet initialized at this moment
272 * Don't save anything to stack even if compiled with -O0
273 *
274 *************************************************************************/
275ENTRY(save_boot_params)
276	bx	lr			@ back to my caller
277ENDPROC(save_boot_params)
278	.weak	save_boot_params
279
280/*************************************************************************
281 *
282 * cpu_init_cp15
283 *
284 * Setup CP15 registers (cache, MMU, TLBs). The I-cache is turned on unless
285 * CONFIG_SYS_ICACHE_OFF is defined.
286 *
287 *************************************************************************/
288ENTRY(cpu_init_cp15)
289	/*
290	 * Invalidate L1 I/D
291	 */
292	mov	r0, #0			@ set up for MCR
293	mcr	p15, 0, r0, c8, c7, 0	@ invalidate TLBs
294	mcr	p15, 0, r0, c7, c5, 0	@ invalidate icache
295	mcr	p15, 0, r0, c7, c5, 6	@ invalidate BP array
296	mcr     p15, 0, r0, c7, c10, 4	@ DSB
297	mcr     p15, 0, r0, c7, c5, 4	@ ISB
298
299	/*
300	 * disable MMU stuff and caches
301	 */
302	mrc	p15, 0, r0, c1, c0, 0
303	bic	r0, r0, #0x00002000	@ clear bits 13 (--V-)
304	bic	r0, r0, #0x00000007	@ clear bits 2:0 (-CAM)
305	orr	r0, r0, #0x00000002	@ set bit 1 (--A-) Align
306	orr	r0, r0, #0x00000800	@ set bit 11 (Z---) BTB
307#ifdef CONFIG_SYS_ICACHE_OFF
308	bic	r0, r0, #0x00001000	@ clear bit 12 (I) I-cache
309#else
310	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-cache
311#endif
312	mcr	p15, 0, r0, c1, c0, 0
313
314#ifdef CONFIG_ARM_ERRATA_716044
315	mrc	p15, 0, r0, c1, c0, 0	@ read system control register
316	orr	r0, r0, #1 << 11	@ set bit #11
317	mcr	p15, 0, r0, c1, c0, 0	@ write system control register
318#endif
319
320#ifdef CONFIG_ARM_ERRATA_742230
321	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
322	orr	r0, r0, #1 << 4		@ set bit #4
323	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
324#endif
325
326#ifdef CONFIG_ARM_ERRATA_743622
327	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
328	orr	r0, r0, #1 << 6		@ set bit #6
329	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
330#endif
331
332#ifdef CONFIG_ARM_ERRATA_751472
333	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
334	orr	r0, r0, #1 << 11	@ set bit #11
335	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
336#endif
337
338	mov	pc, lr			@ back to my caller
339ENDPROC(cpu_init_cp15)
340
341#ifndef CONFIG_SKIP_LOWLEVEL_INIT
342/*************************************************************************
343 *
344 * CPU_init_critical registers
345 *
346 * setup important registers
347 * setup memory timing
348 *
349 *************************************************************************/
350ENTRY(cpu_init_crit)
351	/*
352	 * Jump to board specific initialization...
353	 * The Mask ROM will have already initialized
354	 * basic memory. Go here to bump up clock rate and handle
355	 * wake up conditions.
356	 */
357	b	lowlevel_init		@ go setup pll,mux,memory
358ENDPROC(cpu_init_crit)
359#endif
360
361#ifndef CONFIG_SPL_BUILD
362/*
363 *************************************************************************
364 *
365 * Interrupt handling
366 *
367 *************************************************************************
368 */
369@
370@ IRQ stack frame.
371@
372#define S_FRAME_SIZE	72
373
374#define S_OLD_R0	68
375#define S_PSR		64
376#define S_PC		60
377#define S_LR		56
378#define S_SP		52
379
380#define S_IP		48
381#define S_FP		44
382#define S_R10		40
383#define S_R9		36
384#define S_R8		32
385#define S_R7		28
386#define S_R6		24
387#define S_R5		20
388#define S_R4		16
389#define S_R3		12
390#define S_R2		8
391#define S_R1		4
392#define S_R0		0
393
394#define MODE_SVC 0x13
395#define I_BIT	 0x80
396
397/*
398 * use bad_save_user_regs for abort/prefetch/undef/swi ...
399 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
400 */
401
402	.macro	bad_save_user_regs
403	sub	sp, sp, #S_FRAME_SIZE		@ carve out a frame on current
404						@ user stack
405	stmia	sp, {r0 - r12}			@ Save user registers (now in
406						@ svc mode) r0-r12
407	ldr	r2, IRQ_STACK_START_IN		@ set base 2 words into abort
408						@ stack
409	ldmia	r2, {r2 - r3}			@ get values for "aborted" pc
410						@ and cpsr (into parm regs)
411	add	r0, sp, #S_FRAME_SIZE		@ grab pointer to old stack
412
413	add	r5, sp, #S_SP
414	mov	r1, lr
415	stmia	r5, {r0 - r3}			@ save sp_SVC, lr_SVC, pc, cpsr
416	mov	r0, sp				@ save current stack into r0
417						@ (param register)
418	.endm
419
420	.macro	irq_save_user_regs
421	sub	sp, sp, #S_FRAME_SIZE
422	stmia	sp, {r0 - r12}			@ Calling r0-r12
423	add	r8, sp, #S_PC			@ !! R8 NEEDS to be saved !!
424						@ a reserved stack spot would
425						@ be good.
426	stmdb	r8, {sp, lr}^			@ Calling SP, LR
427	str	lr, [r8, #0]			@ Save calling PC
428	mrs	r6, spsr
429	str	r6, [r8, #4]			@ Save CPSR
430	str	r0, [r8, #8]			@ Save OLD_R0
431	mov	r0, sp
432	.endm
433
434	.macro	irq_restore_user_regs
435	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
436	mov	r0, r0
437	ldr	lr, [sp, #S_PC]			@ Get PC
438	add	sp, sp, #S_FRAME_SIZE
439	subs	pc, lr, #4			@ return & move spsr_svc into
440						@ cpsr
441	.endm
442
443	.macro get_bad_stack
444	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack (enter
445						@ in banked mode)
446
447	str	lr, [r13]			@ save caller lr in position 0
448						@ of saved stack
449	mrs	lr, spsr			@ get the spsr
450	str	lr, [r13, #4]			@ save spsr in position 1 of
451						@ saved stack
452
453	mov	r13, #MODE_SVC			@ prepare SVC-Mode
454	@ msr	spsr_c, r13
455	msr	spsr, r13			@ switch modes, make sure
456						@ moves will execute
457	mov	lr, pc				@ capture return pc
458	movs	pc, lr				@ jump to next instruction &
459						@ switch modes.
460	.endm
461
462	.macro get_bad_stack_swi
463	sub	r13, r13, #4			@ space on current stack for
464						@ scratch reg.
465	str	r0, [r13]			@ save R0's value.
466	ldr	r0, IRQ_STACK_START_IN		@ get data regions start
467						@ spots for abort stack
468	str	lr, [r0]			@ save caller lr in position 0
469						@ of saved stack
470	mrs	r0, spsr			@ get the spsr
471	str	lr, [r0, #4]			@ save spsr in position 1 of
472						@ saved stack
473	ldr	r0, [r13]			@ restore r0
474	add	r13, r13, #4			@ pop stack entry
475	.endm
476
477	.macro get_irq_stack			@ setup IRQ stack
478	ldr	sp, IRQ_STACK_START
479	.endm
480
481	.macro get_fiq_stack			@ setup FIQ stack
482	ldr	sp, FIQ_STACK_START
483	.endm
484
485/*
486 * exception handlers
487 */
488	.align	5
489undefined_instruction:
490	get_bad_stack
491	bad_save_user_regs
492	bl	do_undefined_instruction
493
494	.align	5
495software_interrupt:
496	get_bad_stack_swi
497	bad_save_user_regs
498	bl	do_software_interrupt
499
500	.align	5
501prefetch_abort:
502	get_bad_stack
503	bad_save_user_regs
504	bl	do_prefetch_abort
505
506	.align	5
507data_abort:
508	get_bad_stack
509	bad_save_user_regs
510	bl	do_data_abort
511
512	.align	5
513not_used:
514	get_bad_stack
515	bad_save_user_regs
516	bl	do_not_used
517
518#ifdef CONFIG_USE_IRQ
519
520	.align	5
521irq:
522	get_irq_stack
523	irq_save_user_regs
524	bl	do_irq
525	irq_restore_user_regs
526
527	.align	5
528fiq:
529	get_fiq_stack
530	/* someone ought to write a more effective fiq_save_user_regs */
531	irq_save_user_regs
532	bl	do_fiq
533	irq_restore_user_regs
534
535#else
536
537	.align	5
538irq:
539	get_bad_stack
540	bad_save_user_regs
541	bl	do_irq
542
543	.align	5
544fiq:
545	get_bad_stack
546	bad_save_user_regs
547	bl	do_fiq
548
549#endif /* CONFIG_USE_IRQ */
550#endif /* CONFIG_SPL_BUILD */
551