xref: /openbmc/u-boot/arch/arm/cpu/arm1176/start.S (revision af2a4093)
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.globl _end_ofs
127_end_ofs:
128	.word _end - _start
129
130/* IRQ stack memory (calculated at run-time) + 8 bytes */
131.globl IRQ_STACK_START_IN
132IRQ_STACK_START_IN:
133	.word	0x0badc0de
134
135/*
136 * the actual reset code
137 */
138
139reset:
140	/*
141	 * set the cpu to SVC32 mode
142	 */
143	mrs	r0, cpsr
144	bic	r0, r0, #0x3f
145	orr	r0, r0, #0xd3
146	msr	cpsr, r0
147
148/*
149 *************************************************************************
150 *
151 * CPU_init_critical registers
152 *
153 * setup important registers
154 * setup memory timing
155 *
156 *************************************************************************
157 */
158	/*
159	 * we do sys-critical inits only at reboot,
160	 * not when booting from ram!
161	 */
162cpu_init_crit:
163	/*
164	 * When booting from NAND - it has definitely been a reset, so, no need
165	 * to flush caches and disable the MMU
166	 */
167#ifndef CONFIG_NAND_SPL
168	/*
169	 * flush v4 I/D caches
170	 */
171	mov	r0, #0
172	mcr	p15, 0, r0, c7, c7, 0	/* flush v3/v4 cache */
173	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
174
175	/*
176	 * disable MMU stuff and caches
177	 */
178	mrc	p15, 0, r0, c1, c0, 0
179	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
180	bic	r0, r0, #0x00000087	@ clear bits 7, 2:0 (B--- -CAM)
181	orr	r0, r0, #0x00000002	@ set bit 2 (A) Align
182	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-Cache
183
184	/* Prepare to disable the MMU */
185	adr	r2, mmu_disable_phys
186	sub	r2, r2, #(CONFIG_SYS_PHY_UBOOT_BASE - CONFIG_SYS_TEXT_BASE)
187	b	mmu_disable
188
189	.align 5
190	/* Run in a single cache-line */
191mmu_disable:
192	mcr	p15, 0, r0, c1, c0, 0
193	nop
194	nop
195	mov	pc, r2
196mmu_disable_phys:
197
198#ifdef CONFIG_DISABLE_TCM
199	/*
200	 * Disable the TCMs
201	 */
202	mrc	p15, 0, r0, c0, c0, 2	/* Return TCM details */
203	cmp	r0, #0
204	beq	skip_tcmdisable
205	mov	r1, #0
206	mov	r2, #1
207	tst	r0, r2
208	mcrne	p15, 0, r1, c9, c1, 1	/* Disable Instruction TCM if present*/
209	tst	r0, r2, LSL #16
210	mcrne	p15, 0, r1, c9, c1, 0	/* Disable Data TCM if present*/
211skip_tcmdisable:
212#endif
213#endif
214
215#ifdef CONFIG_PERIPORT_REMAP
216	/* Peri port setup */
217	ldr	r0, =CONFIG_PERIPORT_BASE
218	orr	r0, r0, #CONFIG_PERIPORT_SIZE
219	mcr	p15,0,r0,c15,c2,4
220#endif
221
222	/*
223	 * Go setup Memory and board specific bits prior to relocation.
224	 */
225	bl	lowlevel_init		/* go setup pll,mux,memory */
226
227/* Set stackpointer in internal RAM to call board_init_f */
228call_board_init_f:
229	ldr	sp, =(CONFIG_SYS_INIT_SP_ADDR)
230	bic	sp, sp, #7 /* 8-byte alignment for ABI compliance */
231	ldr	r0,=0x00000000
232	bl	board_init_f
233
234/*------------------------------------------------------------------------------*/
235
236/*
237 * void relocate_code (addr_sp, gd, addr_moni)
238 *
239 * This "function" does not return, instead it continues in RAM
240 * after relocating the monitor code.
241 *
242 */
243	.globl	relocate_code
244relocate_code:
245	mov	r4, r0	/* save addr_sp */
246	mov	r5, r1	/* save addr of gd */
247	mov	r6, r2	/* save addr of destination */
248
249	/* Set up the stack						    */
250stack_setup:
251	mov	sp, r4
252
253	adr	r0, _start
254	cmp	r0, r6
255	moveq	r9, #0		/* no relocation. relocation offset(r9) = 0 */
256	beq	clear_bss		/* skip relocation */
257	mov	r1, r6			/* r1 <- scratch for copy_loop */
258	ldr	r3, _bss_start_ofs
259	add	r2, r0, r3		/* r2 <- source end address	    */
260
261copy_loop:
262	ldmia	r0!, {r9-r10}		/* copy from source address [r0]    */
263	stmia	r1!, {r9-r10}		/* copy to   target address [r1]    */
264	cmp	r0, r2			/* until source end address [r2]    */
265	blo	copy_loop
266
267#ifndef CONFIG_SPL_BUILD
268	/*
269	 * fix .rel.dyn relocations
270	 */
271	ldr	r0, _TEXT_BASE		/* r0 <- Text base */
272	sub	r9, r6, r0		/* r9 <- relocation offset */
273	ldr	r10, _dynsym_start_ofs	/* r10 <- sym table ofs */
274	add	r10, r10, r0		/* r10 <- sym table in FLASH */
275	ldr	r2, _rel_dyn_start_ofs	/* r2 <- rel dyn start ofs */
276	add	r2, r2, r0		/* r2 <- rel dyn start in FLASH */
277	ldr	r3, _rel_dyn_end_ofs	/* r3 <- rel dyn end ofs */
278	add	r3, r3, r0		/* r3 <- rel dyn end in FLASH */
279fixloop:
280	ldr	r0, [r2]		/* r0 <- location to fix up, IN FLASH! */
281	add	r0, r0, r9		/* r0 <- location to fix up in RAM */
282	ldr	r1, [r2, #4]
283	and	r7, r1, #0xff
284	cmp	r7, #23			/* relative fixup? */
285	beq	fixrel
286	cmp	r7, #2			/* absolute fixup? */
287	beq	fixabs
288	/* ignore unknown type of fixup */
289	b	fixnext
290fixabs:
291	/* absolute fix: set location to (offset) symbol value */
292	mov	r1, r1, LSR #4		/* r1 <- symbol index in .dynsym */
293	add	r1, r10, r1		/* r1 <- address of symbol in table */
294	ldr	r1, [r1, #4]		/* r1 <- symbol value */
295	add	r1, r1, r9		/* r1 <- relocated sym addr */
296	b	fixnext
297fixrel:
298	/* relative fix: increase location by offset */
299	ldr	r1, [r0]
300	add	r1, r1, r9
301fixnext:
302	str	r1, [r0]
303	add	r2, r2, #8		/* each rel.dyn entry is 8 bytes */
304	cmp	r2, r3
305	blo	fixloop
306#endif
307
308#ifdef CONFIG_ENABLE_MMU
309enable_mmu:
310	/* enable domain access */
311	ldr	r5, =0x0000ffff
312	mcr	p15, 0, r5, c3, c0, 0	/* load domain access register */
313
314	/* Set the TTB register */
315	ldr	r0, _mmu_table_base
316	ldr	r1, =CONFIG_SYS_PHY_UBOOT_BASE
317	ldr	r2, =0xfff00000
318	bic	r0, r0, r2
319	orr	r1, r0, r1
320	mcr	p15, 0, r1, c2, c0, 0
321
322	/* Enable the MMU */
323	mrc	p15, 0, r0, c1, c0, 0
324	orr	r0, r0, #1		/* Set CR_M to enable MMU */
325
326	/* Prepare to enable the MMU */
327	adr	r1, skip_hw_init
328	and	r1, r1, #0x3fc
329	ldr	r2, _TEXT_BASE
330	ldr	r3, =0xfff00000
331	and	r2, r2, r3
332	orr	r2, r2, r1
333	b	mmu_enable
334
335	.align 5
336	/* Run in a single cache-line */
337mmu_enable:
338
339	mcr	p15, 0, r0, c1, c0, 0
340	nop
341	nop
342	mov	pc, r2
343skip_hw_init:
344#endif
345
346clear_bss:
347#ifndef CONFIG_SPL_BUILD
348	ldr	r0, _bss_start_ofs
349	ldr	r1, _bss_end_ofs
350	mov	r4, r6			/* reloc addr */
351	add	r0, r0, r4
352	add	r1, r1, r4
353	mov	r2, #0x00000000		/* clear			    */
354
355clbss_l:cmp	r0, r1			/* clear loop... */
356	bhs	clbss_e			/* if reached end of bss, exit */
357	str	r2, [r0]
358	add	r0, r0, #4
359	b	clbss_l
360clbss_e:
361#ifndef CONFIG_NAND_SPL
362	bl coloured_LED_init
363	bl red_led_on
364#endif
365#endif
366
367/*
368 * We are done. Do not return, instead branch to second part of board
369 * initialization, now running from RAM.
370 */
371#ifdef CONFIG_NAND_SPL
372	ldr     pc, _nand_boot
373
374_nand_boot: .word nand_boot
375#else
376	ldr	r0, _board_init_r_ofs
377	adr	r1, _start
378	add	lr, r0, r1
379	add     lr, lr, r9
380	/* setup parameters for board_init_r */
381	mov	r0, r5		/* gd_t */
382	mov	r1, r6		/* dest_addr */
383	/* jump to it ... */
384	mov	pc, lr
385
386_board_init_r_ofs:
387	.word board_init_r - _start
388#endif
389
390_rel_dyn_start_ofs:
391	.word __rel_dyn_start - _start
392_rel_dyn_end_ofs:
393	.word __rel_dyn_end - _start
394_dynsym_start_ofs:
395	.word __dynsym_start - _start
396
397#ifdef CONFIG_ENABLE_MMU
398_mmu_table_base:
399	.word mmu_table
400#endif
401
402#ifndef CONFIG_NAND_SPL
403/*
404 * we assume that cache operation is done before. (eg. cleanup_before_linux())
405 * actually, we don't need to do anything about cache if not use d-cache in
406 * U-Boot. So, in this function we clean only MMU. by scsuh
407 *
408 * void	theLastJump(void *kernel, int arch_num, uint boot_params);
409 */
410#ifdef CONFIG_ENABLE_MMU
411	.globl theLastJump
412theLastJump:
413	mov	r9, r0
414	ldr	r3, =0xfff00000
415	ldr	r4, _TEXT_PHY_BASE
416	adr	r5, phy_last_jump
417	bic	r5, r5, r3
418	orr	r5, r5, r4
419	mov	pc, r5
420phy_last_jump:
421	/*
422	 * disable MMU stuff
423	 */
424	mrc	p15, 0, r0, c1, c0, 0
425	bic	r0, r0, #0x00002300	/* clear bits 13, 9:8 (--V- --RS) */
426	bic	r0, r0, #0x00000087	/* clear bits 7, 2:0 (B--- -CAM) */
427	orr	r0, r0, #0x00000002	/* set bit 2 (A) Align */
428	orr	r0, r0, #0x00001000	/* set bit 12 (I) I-Cache */
429	mcr	p15, 0, r0, c1, c0, 0
430
431	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
432
433	mov	r0, #0
434	mov	pc, r9
435#endif
436
437
438/*
439 *************************************************************************
440 *
441 * Interrupt handling
442 *
443 *************************************************************************
444 */
445@
446@ IRQ stack frame.
447@
448#define S_FRAME_SIZE	72
449
450#define S_OLD_R0	68
451#define S_PSR		64
452#define S_PC		60
453#define S_LR		56
454#define S_SP		52
455
456#define S_IP		48
457#define S_FP		44
458#define S_R10		40
459#define S_R9		36
460#define S_R8		32
461#define S_R7		28
462#define S_R6		24
463#define S_R5		20
464#define S_R4		16
465#define S_R3		12
466#define S_R2		8
467#define S_R1		4
468#define S_R0		0
469
470#define MODE_SVC 0x13
471#define I_BIT	 0x80
472
473/*
474 * use bad_save_user_regs for abort/prefetch/undef/swi ...
475 */
476
477	.macro	bad_save_user_regs
478	/* carve out a frame on current user stack */
479	sub	sp, sp, #S_FRAME_SIZE
480	/* Save user registers (now in svc mode) r0-r12 */
481	stmia	sp, {r0 - r12}
482
483	ldr	r2, IRQ_STACK_START_IN
484	/* get values for "aborted" pc and cpsr (into parm regs) */
485	ldmia	r2, {r2 - r3}
486	/* grab pointer to old stack */
487	add	r0, sp, #S_FRAME_SIZE
488
489	add	r5, sp, #S_SP
490	mov	r1, lr
491	/* save sp_SVC, lr_SVC, pc, cpsr */
492	stmia	r5, {r0 - r3}
493	/* save current stack into r0 (param register) */
494	mov	r0, sp
495	.endm
496
497	.macro get_bad_stack
498	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
499
500	/* save caller lr in position 0 of saved stack */
501	str	lr, [r13]
502	/* get the spsr */
503	mrs	lr, spsr
504	/* save spsr in position 1 of saved stack */
505	str	lr, [r13, #4]
506
507	/* prepare SVC-Mode */
508	mov	r13, #MODE_SVC
509	@ msr	spsr_c, r13
510	/* switch modes, make sure moves will execute */
511	msr	spsr, r13
512	/* capture return pc */
513	mov	lr, pc
514	/* jump to next instruction & switch modes. */
515	movs	pc, lr
516	.endm
517
518	.macro get_bad_stack_swi
519	/* space on current stack for scratch reg. */
520	sub	r13, r13, #4
521	/* save R0's value. */
522	str	r0, [r13]
523	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
524	/* save caller lr in position 0 of saved stack */
525	str	lr, [r0]
526	/* get the spsr */
527	mrs	r0, spsr
528	/* save spsr in position 1 of saved stack */
529	str	lr, [r0, #4]
530	/* restore r0 */
531	ldr	r0, [r13]
532	/* pop stack entry */
533	add	r13, r13, #4
534	.endm
535
536/*
537 * exception handlers
538 */
539	.align	5
540undefined_instruction:
541	get_bad_stack
542	bad_save_user_regs
543	bl	do_undefined_instruction
544
545	.align	5
546software_interrupt:
547	get_bad_stack_swi
548	bad_save_user_regs
549	bl	do_software_interrupt
550
551	.align	5
552prefetch_abort:
553	get_bad_stack
554	bad_save_user_regs
555	bl	do_prefetch_abort
556
557	.align	5
558data_abort:
559	get_bad_stack
560	bad_save_user_regs
561	bl	do_data_abort
562
563	.align	5
564not_used:
565	get_bad_stack
566	bad_save_user_regs
567	bl	do_not_used
568
569	.align	5
570irq:
571	get_bad_stack
572	bad_save_user_regs
573	bl	do_irq
574
575	.align	5
576fiq:
577	get_bad_stack
578	bad_save_user_regs
579	bl	do_fiq
580#endif /* CONFIG_NAND_SPL */
581