xref: /openbmc/u-boot/arch/arm/cpu/arm1176/start.S (revision 44c6e6591cb451ae606f8bde71dd5fb7b4002544)
1/*
2 *  armboot - Startup Code for ARM1176 CPU-core
3 *
4 * Copyright (c) 2007	Samsung Electronics
5 *
6 * Copyright (C) 2008
7 * Guennadi Liakhovetki, DENX Software Engineering, <lg@denx.de>
8 *
9 * See file CREDITS for list of people who contributed to this
10 * project.
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License as
14 * published by the Free Software Foundation; either version 2 of
15 * the License, or (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
25 * MA 02111-1307 USA
26 *
27 * 2007-09-21 - Restructured codes by jsgood (jsgood.yang@samsung.com)
28 * 2007-09-21 - Added MoviNAND and OneNAND boot codes by
29 * jsgood (jsgood.yang@samsung.com)
30 * Base codes by scsuh (sc.suh)
31 */
32
33#include <asm-offsets.h>
34#include <config.h>
35#include <version.h>
36#ifdef CONFIG_ENABLE_MMU
37#include <asm/proc/domain.h>
38#endif
39
40#if !defined(CONFIG_ENABLE_MMU) && !defined(CONFIG_SYS_PHY_UBOOT_BASE)
41#define CONFIG_SYS_PHY_UBOOT_BASE	CONFIG_SYS_UBOOT_BASE
42#endif
43
44/*
45 *************************************************************************
46 *
47 * Jump vector table as in table 3.1 in [1]
48 *
49 *************************************************************************
50 */
51
52.globl _start
53_start: b	reset
54#ifndef CONFIG_NAND_SPL
55	ldr	pc, _undefined_instruction
56	ldr	pc, _software_interrupt
57	ldr	pc, _prefetch_abort
58	ldr	pc, _data_abort
59	ldr	pc, _not_used
60	ldr	pc, _irq
61	ldr	pc, _fiq
62
63_undefined_instruction:
64	.word undefined_instruction
65_software_interrupt:
66	.word software_interrupt
67_prefetch_abort:
68	.word prefetch_abort
69_data_abort:
70	.word data_abort
71_not_used:
72	.word not_used
73_irq:
74	.word irq
75_fiq:
76	.word fiq
77_pad:
78	.word 0x12345678 /* now 16*4=64 */
79#else
80	. = _start + 64
81#endif
82
83.global _end_vect
84_end_vect:
85	.balignl 16,0xdeadbeef
86/*
87 *************************************************************************
88 *
89 * Startup Code (reset vector)
90 *
91 * do important init only if we don't start from memory!
92 * setup Memory and board specific bits prior to relocation.
93 * relocate armboot to ram
94 * setup stack
95 *
96 *************************************************************************
97 */
98
99.globl _TEXT_BASE
100_TEXT_BASE:
101	.word	CONFIG_SYS_TEXT_BASE
102
103/*
104 * Below variable is very important because we use MMU in U-Boot.
105 * Without it, we cannot run code correctly before MMU is ON.
106 * by scsuh.
107 */
108_TEXT_PHY_BASE:
109	.word	CONFIG_SYS_PHY_UBOOT_BASE
110
111/*
112 * These are defined in the board-specific linker script.
113 * Subtracting _start from them lets the linker put their
114 * relative position in the executable instead of leaving
115 * them null.
116 */
117
118.globl _bss_start_ofs
119_bss_start_ofs:
120	.word __bss_start - _start
121
122.globl _bss_end_ofs
123_bss_end_ofs:
124	.word __bss_end__ - _start
125
126/* IRQ stack memory (calculated at run-time) + 8 bytes */
127.globl IRQ_STACK_START_IN
128IRQ_STACK_START_IN:
129	.word	0x0badc0de
130
131/*
132 * the actual reset code
133 */
134
135reset:
136	/*
137	 * set the cpu to SVC32 mode
138	 */
139	mrs	r0, cpsr
140	bic	r0, r0, #0x3f
141	orr	r0, r0, #0xd3
142	msr	cpsr, r0
143
144/*
145 *************************************************************************
146 *
147 * CPU_init_critical registers
148 *
149 * setup important registers
150 * setup memory timing
151 *
152 *************************************************************************
153 */
154	/*
155	 * we do sys-critical inits only at reboot,
156	 * not when booting from ram!
157	 */
158cpu_init_crit:
159	/*
160	 * When booting from NAND - it has definitely been a reset, so, no need
161	 * to flush caches and disable the MMU
162	 */
163#ifndef CONFIG_NAND_SPL
164	/*
165	 * flush v4 I/D caches
166	 */
167	mov	r0, #0
168	mcr	p15, 0, r0, c7, c7, 0	/* flush v3/v4 cache */
169	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
170
171	/*
172	 * disable MMU stuff and caches
173	 */
174	mrc	p15, 0, r0, c1, c0, 0
175	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
176	bic	r0, r0, #0x00000087	@ clear bits 7, 2:0 (B--- -CAM)
177	orr	r0, r0, #0x00000002	@ set bit 2 (A) Align
178	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-Cache
179
180	/* Prepare to disable the MMU */
181	adr	r2, mmu_disable_phys
182	sub	r2, r2, #(CONFIG_SYS_PHY_UBOOT_BASE - CONFIG_SYS_TEXT_BASE)
183	b	mmu_disable
184
185	.align 5
186	/* Run in a single cache-line */
187mmu_disable:
188	mcr	p15, 0, r0, c1, c0, 0
189	nop
190	nop
191	mov	pc, r2
192mmu_disable_phys:
193
194#ifdef CONFIG_DISABLE_TCM
195	/*
196	 * Disable the TCMs
197	 */
198	mrc	p15, 0, r0, c0, c0, 2	/* Return TCM details */
199	cmp	r0, #0
200	beq	skip_tcmdisable
201	mov	r1, #0
202	mov	r2, #1
203	tst	r0, r2
204	mcrne	p15, 0, r1, c9, c1, 1	/* Disable Instruction TCM if present*/
205	tst	r0, r2, LSL #16
206	mcrne	p15, 0, r1, c9, c1, 0	/* Disable Data TCM if present*/
207skip_tcmdisable:
208#endif
209#endif
210
211#ifdef CONFIG_PERIPORT_REMAP
212	/* Peri port setup */
213	ldr	r0, =CONFIG_PERIPORT_BASE
214	orr	r0, r0, #CONFIG_PERIPORT_SIZE
215	mcr	p15,0,r0,c15,c2,4
216#endif
217
218	/*
219	 * Go setup Memory and board specific bits prior to relocation.
220	 */
221	bl	lowlevel_init		/* go setup pll,mux,memory */
222
223/* Set stackpointer in internal RAM to call board_init_f */
224call_board_init_f:
225	ldr	sp, =(CONFIG_SYS_INIT_SP_ADDR)
226	bic	sp, sp, #7 /* 8-byte alignment for ABI compliance */
227	ldr	r0,=0x00000000
228	bl	board_init_f
229
230/*------------------------------------------------------------------------------*/
231
232/*
233 * void relocate_code (addr_sp, gd, addr_moni)
234 *
235 * This "function" does not return, instead it continues in RAM
236 * after relocating the monitor code.
237 *
238 */
239	.globl	relocate_code
240relocate_code:
241	mov	r4, r0	/* save addr_sp */
242	mov	r5, r1	/* save addr of gd */
243	mov	r6, r2	/* save addr of destination */
244
245	/* Set up the stack						    */
246stack_setup:
247	mov	sp, r4
248
249	adr	r0, _start
250	cmp	r0, r6
251	beq	clear_bss		/* skip relocation */
252	mov	r1, r6			/* r1 <- scratch for copy_loop */
253	ldr	r3, _bss_start_ofs
254	add	r2, r0, r3		/* r2 <- source end address	    */
255
256copy_loop:
257	ldmia	r0!, {r9-r10}		/* copy from source address [r0]    */
258	stmia	r1!, {r9-r10}		/* copy to   target address [r1]    */
259	cmp	r0, r2			/* until source end address [r2]    */
260	blo	copy_loop
261
262#ifndef CONFIG_PRELOADER
263	/*
264	 * fix .rel.dyn relocations
265	 */
266	ldr	r0, _TEXT_BASE		/* r0 <- Text base */
267	sub	r9, r6, r0		/* r9 <- relocation offset */
268	ldr	r10, _dynsym_start_ofs	/* r10 <- sym table ofs */
269	add	r10, r10, r0		/* r10 <- sym table in FLASH */
270	ldr	r2, _rel_dyn_start_ofs	/* r2 <- rel dyn start ofs */
271	add	r2, r2, r0		/* r2 <- rel dyn start in FLASH */
272	ldr	r3, _rel_dyn_end_ofs	/* r3 <- rel dyn end ofs */
273	add	r3, r3, r0		/* r3 <- rel dyn end in FLASH */
274fixloop:
275	ldr	r0, [r2]		/* r0 <- location to fix up, IN FLASH! */
276	add	r0, r0, r9		/* r0 <- location to fix up in RAM */
277	ldr	r1, [r2, #4]
278	and	r7, r1, #0xff
279	cmp	r7, #23			/* relative fixup? */
280	beq	fixrel
281	cmp	r7, #2			/* absolute fixup? */
282	beq	fixabs
283	/* ignore unknown type of fixup */
284	b	fixnext
285fixabs:
286	/* absolute fix: set location to (offset) symbol value */
287	mov	r1, r1, LSR #4		/* r1 <- symbol index in .dynsym */
288	add	r1, r10, r1		/* r1 <- address of symbol in table */
289	ldr	r1, [r1, #4]		/* r1 <- symbol value */
290	add	r1, r1, r9		/* r1 <- relocated sym addr */
291	b	fixnext
292fixrel:
293	/* relative fix: increase location by offset */
294	ldr	r1, [r0]
295	add	r1, r1, r9
296fixnext:
297	str	r1, [r0]
298	add	r2, r2, #8		/* each rel.dyn entry is 8 bytes */
299	cmp	r2, r3
300	blo	fixloop
301#endif
302
303#ifdef CONFIG_ENABLE_MMU
304enable_mmu:
305	/* enable domain access */
306	ldr	r5, =0x0000ffff
307	mcr	p15, 0, r5, c3, c0, 0	/* load domain access register */
308
309	/* Set the TTB register */
310	ldr	r0, _mmu_table_base
311	ldr	r1, =CONFIG_SYS_PHY_UBOOT_BASE
312	ldr	r2, =0xfff00000
313	bic	r0, r0, r2
314	orr	r1, r0, r1
315	mcr	p15, 0, r1, c2, c0, 0
316
317	/* Enable the MMU */
318	mrc	p15, 0, r0, c1, c0, 0
319	orr	r0, r0, #1		/* Set CR_M to enable MMU */
320
321	/* Prepare to enable the MMU */
322	adr	r1, skip_hw_init
323	and	r1, r1, #0x3fc
324	ldr	r2, _TEXT_BASE
325	ldr	r3, =0xfff00000
326	and	r2, r2, r3
327	orr	r2, r2, r1
328	b	mmu_enable
329
330	.align 5
331	/* Run in a single cache-line */
332mmu_enable:
333
334	mcr	p15, 0, r0, c1, c0, 0
335	nop
336	nop
337	mov	pc, r2
338skip_hw_init:
339#endif
340
341clear_bss:
342#ifndef CONFIG_PRELOADER
343	ldr	r0, _bss_start_ofs
344	ldr	r1, _bss_end_ofs
345	mov	r4, r6			/* reloc addr */
346	add	r0, r0, r4
347	add	r1, r1, r4
348	mov	r2, #0x00000000		/* clear			    */
349
350clbss_l:str	r2, [r0]		/* clear loop...		    */
351	add	r0, r0, #4
352	cmp	r0, r1
353	bne	clbss_l
354
355	bl coloured_LED_init
356	bl red_LED_on
357#endif
358
359/*
360 * We are done. Do not return, instead branch to second part of board
361 * initialization, now running from RAM.
362 */
363#ifdef CONFIG_NAND_SPL
364	ldr     pc, _nand_boot
365
366_nand_boot: .word nand_boot
367#else
368	ldr	r0, _board_init_r_ofs
369	adr	r1, _start
370	add	lr, r0, r1
371	add     lr, lr, r9
372	/* setup parameters for board_init_r */
373	mov	r0, r5		/* gd_t */
374	mov	r1, r6		/* dest_addr */
375	/* jump to it ... */
376	mov	pc, lr
377
378_board_init_r_ofs:
379	.word board_init_r - _start
380#endif
381
382_rel_dyn_start_ofs:
383	.word __rel_dyn_start - _start
384_rel_dyn_end_ofs:
385	.word __rel_dyn_end - _start
386_dynsym_start_ofs:
387	.word __dynsym_start - _start
388
389#ifdef CONFIG_ENABLE_MMU
390_mmu_table_base:
391	.word mmu_table
392#endif
393
394#ifndef CONFIG_NAND_SPL
395/*
396 * we assume that cache operation is done before. (eg. cleanup_before_linux())
397 * actually, we don't need to do anything about cache if not use d-cache in
398 * U-Boot. So, in this function we clean only MMU. by scsuh
399 *
400 * void	theLastJump(void *kernel, int arch_num, uint boot_params);
401 */
402#ifdef CONFIG_ENABLE_MMU
403	.globl theLastJump
404theLastJump:
405	mov	r9, r0
406	ldr	r3, =0xfff00000
407	ldr	r4, _TEXT_PHY_BASE
408	adr	r5, phy_last_jump
409	bic	r5, r5, r3
410	orr	r5, r5, r4
411	mov	pc, r5
412phy_last_jump:
413	/*
414	 * disable MMU stuff
415	 */
416	mrc	p15, 0, r0, c1, c0, 0
417	bic	r0, r0, #0x00002300	/* clear bits 13, 9:8 (--V- --RS) */
418	bic	r0, r0, #0x00000087	/* clear bits 7, 2:0 (B--- -CAM) */
419	orr	r0, r0, #0x00000002	/* set bit 2 (A) Align */
420	orr	r0, r0, #0x00001000	/* set bit 12 (I) I-Cache */
421	mcr	p15, 0, r0, c1, c0, 0
422
423	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
424
425	mov	r0, #0
426	mov	pc, r9
427#endif
428
429
430/*
431 *************************************************************************
432 *
433 * Interrupt handling
434 *
435 *************************************************************************
436 */
437@
438@ IRQ stack frame.
439@
440#define S_FRAME_SIZE	72
441
442#define S_OLD_R0	68
443#define S_PSR		64
444#define S_PC		60
445#define S_LR		56
446#define S_SP		52
447
448#define S_IP		48
449#define S_FP		44
450#define S_R10		40
451#define S_R9		36
452#define S_R8		32
453#define S_R7		28
454#define S_R6		24
455#define S_R5		20
456#define S_R4		16
457#define S_R3		12
458#define S_R2		8
459#define S_R1		4
460#define S_R0		0
461
462#define MODE_SVC 0x13
463#define I_BIT	 0x80
464
465/*
466 * use bad_save_user_regs for abort/prefetch/undef/swi ...
467 */
468
469	.macro	bad_save_user_regs
470	/* carve out a frame on current user stack */
471	sub	sp, sp, #S_FRAME_SIZE
472	/* Save user registers (now in svc mode) r0-r12 */
473	stmia	sp, {r0 - r12}
474
475	ldr	r2, IRQ_STACK_START_IN
476	/* get values for "aborted" pc and cpsr (into parm regs) */
477	ldmia	r2, {r2 - r3}
478	/* grab pointer to old stack */
479	add	r0, sp, #S_FRAME_SIZE
480
481	add	r5, sp, #S_SP
482	mov	r1, lr
483	/* save sp_SVC, lr_SVC, pc, cpsr */
484	stmia	r5, {r0 - r3}
485	/* save current stack into r0 (param register) */
486	mov	r0, sp
487	.endm
488
489	.macro get_bad_stack
490	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
491
492	/* save caller lr in position 0 of saved stack */
493	str	lr, [r13]
494	/* get the spsr */
495	mrs	lr, spsr
496	/* save spsr in position 1 of saved stack */
497	str	lr, [r13, #4]
498
499	/* prepare SVC-Mode */
500	mov	r13, #MODE_SVC
501	@ msr	spsr_c, r13
502	/* switch modes, make sure moves will execute */
503	msr	spsr, r13
504	/* capture return pc */
505	mov	lr, pc
506	/* jump to next instruction & switch modes. */
507	movs	pc, lr
508	.endm
509
510	.macro get_bad_stack_swi
511	/* space on current stack for scratch reg. */
512	sub	r13, r13, #4
513	/* save R0's value. */
514	str	r0, [r13]
515	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
516	/* save caller lr in position 0 of saved stack */
517	str	lr, [r0]
518	/* get the spsr */
519	mrs	r0, spsr
520	/* save spsr in position 1 of saved stack */
521	str	lr, [r0, #4]
522	/* restore r0 */
523	ldr	r0, [r13]
524	/* pop stack entry */
525	add	r13, r13, #4
526	.endm
527
528/*
529 * exception handlers
530 */
531	.align	5
532undefined_instruction:
533	get_bad_stack
534	bad_save_user_regs
535	bl	do_undefined_instruction
536
537	.align	5
538software_interrupt:
539	get_bad_stack_swi
540	bad_save_user_regs
541	bl	do_software_interrupt
542
543	.align	5
544prefetch_abort:
545	get_bad_stack
546	bad_save_user_regs
547	bl	do_prefetch_abort
548
549	.align	5
550data_abort:
551	get_bad_stack
552	bad_save_user_regs
553	bl	do_data_abort
554
555	.align	5
556not_used:
557	get_bad_stack
558	bad_save_user_regs
559	bl	do_not_used
560
561	.align	5
562irq:
563	get_bad_stack
564	bad_save_user_regs
565	bl	do_irq
566
567	.align	5
568fiq:
569	get_bad_stack
570	bad_save_user_regs
571	bl	do_fiq
572#endif /* CONFIG_NAND_SPL */
573