xref: /openbmc/u-boot/arch/arm/cpu/arm1176/start.S (revision e0306cab)
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 _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	r2, _TEXT_BASE
254	ldr	r3, _bss_start_ofs
255	add	r2, r0, r3		/* r2 <- source end address	    */
256
257copy_loop:
258	ldmia	r0!, {r9-r10}		/* copy from source address [r0]    */
259	stmia	r1!, {r9-r10}		/* copy to   target address [r1]    */
260	cmp	r0, r2			/* until source end address [r2]    */
261	blo	copy_loop
262
263#ifndef CONFIG_PRELOADER
264	/*
265	 * fix .rel.dyn relocations
266	 */
267	ldr	r0, _TEXT_BASE		/* r0 <- Text base */
268	sub	r9, r6, r0		/* r9 <- relocation offset */
269	ldr	r10, _dynsym_start_ofs	/* r10 <- sym table ofs */
270	add	r10, r10, r0		/* r10 <- sym table in FLASH */
271	ldr	r2, _rel_dyn_start_ofs	/* r2 <- rel dyn start ofs */
272	add	r2, r2, r0		/* r2 <- rel dyn start in FLASH */
273	ldr	r3, _rel_dyn_end_ofs	/* r3 <- rel dyn end ofs */
274	add	r3, r3, r0		/* r3 <- rel dyn end in FLASH */
275fixloop:
276	ldr	r0, [r2]		/* r0 <- location to fix up, IN FLASH! */
277	add	r0, r0, r9		/* r0 <- location to fix up in RAM */
278	ldr	r1, [r2, #4]
279	and	r7, r1, #0xff
280	cmp	r7, #23			/* relative fixup? */
281	beq	fixrel
282	cmp	r7, #2			/* absolute fixup? */
283	beq	fixabs
284	/* ignore unknown type of fixup */
285	b	fixnext
286fixabs:
287	/* absolute fix: set location to (offset) symbol value */
288	mov	r1, r1, LSR #4		/* r1 <- symbol index in .dynsym */
289	add	r1, r10, r1		/* r1 <- address of symbol in table */
290	ldr	r1, [r1, #4]		/* r1 <- symbol value */
291	add	r1, r1, r9		/* r1 <- relocated sym addr */
292	b	fixnext
293fixrel:
294	/* relative fix: increase location by offset */
295	ldr	r1, [r0]
296	add	r1, r1, r9
297fixnext:
298	str	r1, [r0]
299	add	r2, r2, #8		/* each rel.dyn entry is 8 bytes */
300	cmp	r2, r3
301	blo	fixloop
302#endif
303
304#ifdef CONFIG_ENABLE_MMU
305enable_mmu:
306	/* enable domain access */
307	ldr	r5, =0x0000ffff
308	mcr	p15, 0, r5, c3, c0, 0	/* load domain access register */
309
310	/* Set the TTB register */
311	ldr	r0, _mmu_table_base
312	ldr	r1, =CONFIG_SYS_PHY_UBOOT_BASE
313	ldr	r2, =0xfff00000
314	bic	r0, r0, r2
315	orr	r1, r0, r1
316	mcr	p15, 0, r1, c2, c0, 0
317
318	/* Enable the MMU */
319	mrc	p15, 0, r0, c1, c0, 0
320	orr	r0, r0, #1		/* Set CR_M to enable MMU */
321
322	/* Prepare to enable the MMU */
323	adr	r1, skip_hw_init
324	and	r1, r1, #0x3fc
325	ldr	r2, _TEXT_BASE
326	ldr	r3, =0xfff00000
327	and	r2, r2, r3
328	orr	r2, r2, r1
329	b	mmu_enable
330
331	.align 5
332	/* Run in a single cache-line */
333mmu_enable:
334
335	mcr	p15, 0, r0, c1, c0, 0
336	nop
337	nop
338	mov	pc, r2
339skip_hw_init:
340#endif
341
342clear_bss:
343#ifndef CONFIG_PRELOADER
344	ldr	r0, _bss_start_ofs
345	ldr	r1, _bss_end_ofs
346	ldr	r3, _TEXT_BASE		/* Text base */
347	mov	r4, r6			/* reloc addr */
348	add	r0, r0, r4
349	add	r1, r1, r4
350	mov	r2, #0x00000000		/* clear			    */
351
352clbss_l:str	r2, [r0]		/* clear loop...		    */
353	add	r0, r0, #4
354	cmp	r0, r1
355	bne	clbss_l
356
357	bl coloured_LED_init
358	bl red_LED_on
359#endif
360
361/*
362 * We are done. Do not return, instead branch to second part of board
363 * initialization, now running from RAM.
364 */
365#ifdef CONFIG_NAND_SPL
366	ldr     pc, _nand_boot
367
368_nand_boot: .word nand_boot
369#else
370	ldr	r0, _board_init_r_ofs
371	adr	r1, _start
372	add	lr, r0, r1
373	add     lr, lr, r9
374	/* setup parameters for board_init_r */
375	mov	r0, r5		/* gd_t */
376	mov	r1, r6		/* dest_addr */
377	/* jump to it ... */
378	mov	pc, lr
379
380_board_init_r_ofs:
381	.word board_init_r - _start
382#endif
383
384_rel_dyn_start_ofs:
385	.word __rel_dyn_start - _start
386_rel_dyn_end_ofs:
387	.word __rel_dyn_end - _start
388_dynsym_start_ofs:
389	.word __dynsym_start - _start
390
391#ifdef CONFIG_ENABLE_MMU
392_mmu_table_base:
393	.word mmu_table
394#endif
395
396#ifndef CONFIG_NAND_SPL
397/*
398 * we assume that cache operation is done before. (eg. cleanup_before_linux())
399 * actually, we don't need to do anything about cache if not use d-cache in
400 * U-Boot. So, in this function we clean only MMU. by scsuh
401 *
402 * void	theLastJump(void *kernel, int arch_num, uint boot_params);
403 */
404#ifdef CONFIG_ENABLE_MMU
405	.globl theLastJump
406theLastJump:
407	mov	r9, r0
408	ldr	r3, =0xfff00000
409	ldr	r4, _TEXT_PHY_BASE
410	adr	r5, phy_last_jump
411	bic	r5, r5, r3
412	orr	r5, r5, r4
413	mov	pc, r5
414phy_last_jump:
415	/*
416	 * disable MMU stuff
417	 */
418	mrc	p15, 0, r0, c1, c0, 0
419	bic	r0, r0, #0x00002300	/* clear bits 13, 9:8 (--V- --RS) */
420	bic	r0, r0, #0x00000087	/* clear bits 7, 2:0 (B--- -CAM) */
421	orr	r0, r0, #0x00000002	/* set bit 2 (A) Align */
422	orr	r0, r0, #0x00001000	/* set bit 12 (I) I-Cache */
423	mcr	p15, 0, r0, c1, c0, 0
424
425	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
426
427	mov	r0, #0
428	mov	pc, r9
429#endif
430
431
432/*
433 *************************************************************************
434 *
435 * Interrupt handling
436 *
437 *************************************************************************
438 */
439@
440@ IRQ stack frame.
441@
442#define S_FRAME_SIZE	72
443
444#define S_OLD_R0	68
445#define S_PSR		64
446#define S_PC		60
447#define S_LR		56
448#define S_SP		52
449
450#define S_IP		48
451#define S_FP		44
452#define S_R10		40
453#define S_R9		36
454#define S_R8		32
455#define S_R7		28
456#define S_R6		24
457#define S_R5		20
458#define S_R4		16
459#define S_R3		12
460#define S_R2		8
461#define S_R1		4
462#define S_R0		0
463
464#define MODE_SVC 0x13
465#define I_BIT	 0x80
466
467/*
468 * use bad_save_user_regs for abort/prefetch/undef/swi ...
469 */
470
471	.macro	bad_save_user_regs
472	/* carve out a frame on current user stack */
473	sub	sp, sp, #S_FRAME_SIZE
474	/* Save user registers (now in svc mode) r0-r12 */
475	stmia	sp, {r0 - r12}
476
477	ldr	r2, IRQ_STACK_START_IN
478	/* get values for "aborted" pc and cpsr (into parm regs) */
479	ldmia	r2, {r2 - r3}
480	/* grab pointer to old stack */
481	add	r0, sp, #S_FRAME_SIZE
482
483	add	r5, sp, #S_SP
484	mov	r1, lr
485	/* save sp_SVC, lr_SVC, pc, cpsr */
486	stmia	r5, {r0 - r3}
487	/* save current stack into r0 (param register) */
488	mov	r0, sp
489	.endm
490
491	.macro get_bad_stack
492	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
493
494	/* save caller lr in position 0 of saved stack */
495	str	lr, [r13]
496	/* get the spsr */
497	mrs	lr, spsr
498	/* save spsr in position 1 of saved stack */
499	str	lr, [r13, #4]
500
501	/* prepare SVC-Mode */
502	mov	r13, #MODE_SVC
503	@ msr	spsr_c, r13
504	/* switch modes, make sure moves will execute */
505	msr	spsr, r13
506	/* capture return pc */
507	mov	lr, pc
508	/* jump to next instruction & switch modes. */
509	movs	pc, lr
510	.endm
511
512	.macro get_bad_stack_swi
513	/* space on current stack for scratch reg. */
514	sub	r13, r13, #4
515	/* save R0's value. */
516	str	r0, [r13]
517	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
518	/* save caller lr in position 0 of saved stack */
519	str	lr, [r0]
520	/* get the spsr */
521	mrs	r0, spsr
522	/* save spsr in position 1 of saved stack */
523	str	lr, [r0, #4]
524	/* restore r0 */
525	ldr	r0, [r13]
526	/* pop stack entry */
527	add	r13, r13, #4
528	.endm
529
530/*
531 * exception handlers
532 */
533	.align	5
534undefined_instruction:
535	get_bad_stack
536	bad_save_user_regs
537	bl	do_undefined_instruction
538
539	.align	5
540software_interrupt:
541	get_bad_stack_swi
542	bad_save_user_regs
543	bl	do_software_interrupt
544
545	.align	5
546prefetch_abort:
547	get_bad_stack
548	bad_save_user_regs
549	bl	do_prefetch_abort
550
551	.align	5
552data_abort:
553	get_bad_stack
554	bad_save_user_regs
555	bl	do_data_abort
556
557	.align	5
558not_used:
559	get_bad_stack
560	bad_save_user_regs
561	bl	do_not_used
562
563	.align	5
564irq:
565	get_bad_stack
566	bad_save_user_regs
567	bl	do_irq
568
569	.align	5
570fiq:
571	get_bad_stack
572	bad_save_user_regs
573	bl	do_fiq
574#endif /* CONFIG_NAND_SPL */
575