xref: /openbmc/u-boot/arch/arm/cpu/arm1176/start.S (revision 6785c7c8)
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	beq	clear_bss		/* skip relocation */
256	mov	r1, r6			/* r1 <- scratch for copy_loop */
257	ldr	r3, _bss_start_ofs
258	add	r2, r0, r3		/* r2 <- source end address	    */
259
260copy_loop:
261	ldmia	r0!, {r9-r10}		/* copy from source address [r0]    */
262	stmia	r1!, {r9-r10}		/* copy to   target address [r1]    */
263	cmp	r0, r2			/* until source end address [r2]    */
264	blo	copy_loop
265
266#ifndef CONFIG_SPL_BUILD
267	/*
268	 * fix .rel.dyn relocations
269	 */
270	ldr	r0, _TEXT_BASE		/* r0 <- Text base */
271	sub	r9, r6, r0		/* r9 <- relocation offset */
272	ldr	r10, _dynsym_start_ofs	/* r10 <- sym table ofs */
273	add	r10, r10, r0		/* r10 <- sym table in FLASH */
274	ldr	r2, _rel_dyn_start_ofs	/* r2 <- rel dyn start ofs */
275	add	r2, r2, r0		/* r2 <- rel dyn start in FLASH */
276	ldr	r3, _rel_dyn_end_ofs	/* r3 <- rel dyn end ofs */
277	add	r3, r3, r0		/* r3 <- rel dyn end in FLASH */
278fixloop:
279	ldr	r0, [r2]		/* r0 <- location to fix up, IN FLASH! */
280	add	r0, r0, r9		/* r0 <- location to fix up in RAM */
281	ldr	r1, [r2, #4]
282	and	r7, r1, #0xff
283	cmp	r7, #23			/* relative fixup? */
284	beq	fixrel
285	cmp	r7, #2			/* absolute fixup? */
286	beq	fixabs
287	/* ignore unknown type of fixup */
288	b	fixnext
289fixabs:
290	/* absolute fix: set location to (offset) symbol value */
291	mov	r1, r1, LSR #4		/* r1 <- symbol index in .dynsym */
292	add	r1, r10, r1		/* r1 <- address of symbol in table */
293	ldr	r1, [r1, #4]		/* r1 <- symbol value */
294	add	r1, r1, r9		/* r1 <- relocated sym addr */
295	b	fixnext
296fixrel:
297	/* relative fix: increase location by offset */
298	ldr	r1, [r0]
299	add	r1, r1, r9
300fixnext:
301	str	r1, [r0]
302	add	r2, r2, #8		/* each rel.dyn entry is 8 bytes */
303	cmp	r2, r3
304	blo	fixloop
305#endif
306
307#ifdef CONFIG_ENABLE_MMU
308enable_mmu:
309	/* enable domain access */
310	ldr	r5, =0x0000ffff
311	mcr	p15, 0, r5, c3, c0, 0	/* load domain access register */
312
313	/* Set the TTB register */
314	ldr	r0, _mmu_table_base
315	ldr	r1, =CONFIG_SYS_PHY_UBOOT_BASE
316	ldr	r2, =0xfff00000
317	bic	r0, r0, r2
318	orr	r1, r0, r1
319	mcr	p15, 0, r1, c2, c0, 0
320
321	/* Enable the MMU */
322	mrc	p15, 0, r0, c1, c0, 0
323	orr	r0, r0, #1		/* Set CR_M to enable MMU */
324
325	/* Prepare to enable the MMU */
326	adr	r1, skip_hw_init
327	and	r1, r1, #0x3fc
328	ldr	r2, _TEXT_BASE
329	ldr	r3, =0xfff00000
330	and	r2, r2, r3
331	orr	r2, r2, r1
332	b	mmu_enable
333
334	.align 5
335	/* Run in a single cache-line */
336mmu_enable:
337
338	mcr	p15, 0, r0, c1, c0, 0
339	nop
340	nop
341	mov	pc, r2
342skip_hw_init:
343#endif
344
345clear_bss:
346#ifndef CONFIG_SPL_BUILD
347	ldr	r0, _bss_start_ofs
348	ldr	r1, _bss_end_ofs
349	mov	r4, r6			/* reloc addr */
350	add	r0, r0, r4
351	add	r1, r1, r4
352	mov	r2, #0x00000000		/* clear			    */
353
354clbss_l:str	r2, [r0]		/* clear loop...		    */
355	add	r0, r0, #4
356	cmp	r0, r1
357	bne	clbss_l
358
359#ifndef CONFIG_NAND_SPL
360	bl coloured_LED_init
361	bl red_LED_on
362#endif
363#endif
364
365/*
366 * We are done. Do not return, instead branch to second part of board
367 * initialization, now running from RAM.
368 */
369#ifdef CONFIG_NAND_SPL
370	ldr     pc, _nand_boot
371
372_nand_boot: .word nand_boot
373#else
374	ldr	r0, _board_init_r_ofs
375	adr	r1, _start
376	add	lr, r0, r1
377	add     lr, lr, r9
378	/* setup parameters for board_init_r */
379	mov	r0, r5		/* gd_t */
380	mov	r1, r6		/* dest_addr */
381	/* jump to it ... */
382	mov	pc, lr
383
384_board_init_r_ofs:
385	.word board_init_r - _start
386#endif
387
388_rel_dyn_start_ofs:
389	.word __rel_dyn_start - _start
390_rel_dyn_end_ofs:
391	.word __rel_dyn_end - _start
392_dynsym_start_ofs:
393	.word __dynsym_start - _start
394
395#ifdef CONFIG_ENABLE_MMU
396_mmu_table_base:
397	.word mmu_table
398#endif
399
400#ifndef CONFIG_NAND_SPL
401/*
402 * we assume that cache operation is done before. (eg. cleanup_before_linux())
403 * actually, we don't need to do anything about cache if not use d-cache in
404 * U-Boot. So, in this function we clean only MMU. by scsuh
405 *
406 * void	theLastJump(void *kernel, int arch_num, uint boot_params);
407 */
408#ifdef CONFIG_ENABLE_MMU
409	.globl theLastJump
410theLastJump:
411	mov	r9, r0
412	ldr	r3, =0xfff00000
413	ldr	r4, _TEXT_PHY_BASE
414	adr	r5, phy_last_jump
415	bic	r5, r5, r3
416	orr	r5, r5, r4
417	mov	pc, r5
418phy_last_jump:
419	/*
420	 * disable MMU stuff
421	 */
422	mrc	p15, 0, r0, c1, c0, 0
423	bic	r0, r0, #0x00002300	/* clear bits 13, 9:8 (--V- --RS) */
424	bic	r0, r0, #0x00000087	/* clear bits 7, 2:0 (B--- -CAM) */
425	orr	r0, r0, #0x00000002	/* set bit 2 (A) Align */
426	orr	r0, r0, #0x00001000	/* set bit 12 (I) I-Cache */
427	mcr	p15, 0, r0, c1, c0, 0
428
429	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
430
431	mov	r0, #0
432	mov	pc, r9
433#endif
434
435
436/*
437 *************************************************************************
438 *
439 * Interrupt handling
440 *
441 *************************************************************************
442 */
443@
444@ IRQ stack frame.
445@
446#define S_FRAME_SIZE	72
447
448#define S_OLD_R0	68
449#define S_PSR		64
450#define S_PC		60
451#define S_LR		56
452#define S_SP		52
453
454#define S_IP		48
455#define S_FP		44
456#define S_R10		40
457#define S_R9		36
458#define S_R8		32
459#define S_R7		28
460#define S_R6		24
461#define S_R5		20
462#define S_R4		16
463#define S_R3		12
464#define S_R2		8
465#define S_R1		4
466#define S_R0		0
467
468#define MODE_SVC 0x13
469#define I_BIT	 0x80
470
471/*
472 * use bad_save_user_regs for abort/prefetch/undef/swi ...
473 */
474
475	.macro	bad_save_user_regs
476	/* carve out a frame on current user stack */
477	sub	sp, sp, #S_FRAME_SIZE
478	/* Save user registers (now in svc mode) r0-r12 */
479	stmia	sp, {r0 - r12}
480
481	ldr	r2, IRQ_STACK_START_IN
482	/* get values for "aborted" pc and cpsr (into parm regs) */
483	ldmia	r2, {r2 - r3}
484	/* grab pointer to old stack */
485	add	r0, sp, #S_FRAME_SIZE
486
487	add	r5, sp, #S_SP
488	mov	r1, lr
489	/* save sp_SVC, lr_SVC, pc, cpsr */
490	stmia	r5, {r0 - r3}
491	/* save current stack into r0 (param register) */
492	mov	r0, sp
493	.endm
494
495	.macro get_bad_stack
496	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
497
498	/* save caller lr in position 0 of saved stack */
499	str	lr, [r13]
500	/* get the spsr */
501	mrs	lr, spsr
502	/* save spsr in position 1 of saved stack */
503	str	lr, [r13, #4]
504
505	/* prepare SVC-Mode */
506	mov	r13, #MODE_SVC
507	@ msr	spsr_c, r13
508	/* switch modes, make sure moves will execute */
509	msr	spsr, r13
510	/* capture return pc */
511	mov	lr, pc
512	/* jump to next instruction & switch modes. */
513	movs	pc, lr
514	.endm
515
516	.macro get_bad_stack_swi
517	/* space on current stack for scratch reg. */
518	sub	r13, r13, #4
519	/* save R0's value. */
520	str	r0, [r13]
521	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
522	/* save caller lr in position 0 of saved stack */
523	str	lr, [r0]
524	/* get the spsr */
525	mrs	r0, spsr
526	/* save spsr in position 1 of saved stack */
527	str	lr, [r0, #4]
528	/* restore r0 */
529	ldr	r0, [r13]
530	/* pop stack entry */
531	add	r13, r13, #4
532	.endm
533
534/*
535 * exception handlers
536 */
537	.align	5
538undefined_instruction:
539	get_bad_stack
540	bad_save_user_regs
541	bl	do_undefined_instruction
542
543	.align	5
544software_interrupt:
545	get_bad_stack_swi
546	bad_save_user_regs
547	bl	do_software_interrupt
548
549	.align	5
550prefetch_abort:
551	get_bad_stack
552	bad_save_user_regs
553	bl	do_prefetch_abort
554
555	.align	5
556data_abort:
557	get_bad_stack
558	bad_save_user_regs
559	bl	do_data_abort
560
561	.align	5
562not_used:
563	get_bad_stack
564	bad_save_user_regs
565	bl	do_not_used
566
567	.align	5
568irq:
569	get_bad_stack
570	bad_save_user_regs
571	bl	do_irq
572
573	.align	5
574fiq:
575	get_bad_stack
576	bad_save_user_regs
577	bl	do_fiq
578#endif /* CONFIG_NAND_SPL */
579