xref: /openbmc/u-boot/arch/arm/cpu/arm1136/start.S (revision 9d86f0c3)
1/*
2 *  armboot - Startup Code for OMP2420/ARM1136 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 *
12 * See file CREDITS for list of people who contributed to this
13 * project.
14 *
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License as
17 * published by the Free Software Foundation; either version 2 of
18 * the License, or (at your option) any later version.
19 *
20 * This program is distributed in the hope that it will be useful,
21 * but WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
23 * GNU General Public License for more details.
24 *
25 * You should have received a copy of the GNU General Public License
26 * along with this program; if not, write to the Free Software
27 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
28 * MA 02111-1307 USA
29 */
30
31#include <asm-offsets.h>
32#include <config.h>
33#include <version.h>
34.globl _start
35_start: b	reset
36#ifdef CONFIG_SPL_BUILD
37	ldr	pc, _hang
38	ldr	pc, _hang
39	ldr	pc, _hang
40	ldr	pc, _hang
41	ldr	pc, _hang
42	ldr	pc, _hang
43	ldr	pc, _hang
44
45_hang:
46	.word	do_hang
47	.word	0x12345678
48	.word	0x12345678
49	.word	0x12345678
50	.word	0x12345678
51	.word	0x12345678
52	.word	0x12345678
53	.word	0x12345678	/* now 16*4=64 */
54#else
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: .word undefined_instruction
64_software_interrupt:	.word software_interrupt
65_prefetch_abort:	.word prefetch_abort
66_data_abort:		.word data_abort
67_not_used:		.word not_used
68_irq:			.word irq
69_fiq:			.word fiq
70_pad:			.word 0x12345678 /* now 16*4=64 */
71#endif	/* CONFIG_SPL_BUILD */
72.global _end_vect
73_end_vect:
74
75	.balignl 16,0xdeadbeef
76/*
77 *************************************************************************
78 *
79 * Startup Code (reset vector)
80 *
81 * do important init only if we don't start from memory!
82 * setup Memory and board specific bits prior to relocation.
83 * relocate armboot to ram
84 * setup stack
85 *
86 *************************************************************************
87 */
88
89.globl _TEXT_BASE
90_TEXT_BASE:
91	.word	CONFIG_SYS_TEXT_BASE
92
93/*
94 * These are defined in the board-specific linker script.
95 * Subtracting _start from them lets the linker put their
96 * relative position in the executable instead of leaving
97 * them null.
98 */
99.globl _bss_start_ofs
100_bss_start_ofs:
101	.word __bss_start - _start
102
103.global	_image_copy_end_ofs
104_image_copy_end_ofs:
105	.word 	__image_copy_end - _start
106
107.globl _bss_end_ofs
108_bss_end_ofs:
109	.word __bss_end__ - _start
110
111.globl _end_ofs
112_end_ofs:
113	.word _end - _start
114
115#ifdef CONFIG_USE_IRQ
116/* IRQ stack memory (calculated at run-time) */
117.globl IRQ_STACK_START
118IRQ_STACK_START:
119	.word	0x0badc0de
120
121/* IRQ stack memory (calculated at run-time) */
122.globl FIQ_STACK_START
123FIQ_STACK_START:
124	.word 0x0badc0de
125#endif
126
127/* IRQ stack memory (calculated at run-time) + 8 bytes */
128.globl IRQ_STACK_START_IN
129IRQ_STACK_START_IN:
130	.word	0x0badc0de
131
132/*
133 * the actual reset code
134 */
135
136reset:
137	/*
138	 * set the cpu to SVC32 mode
139	 */
140	mrs	r0,cpsr
141	bic	r0,r0,#0x1f
142	orr	r0,r0,#0xd3
143	msr	cpsr,r0
144
145#ifdef CONFIG_OMAP2420H4
146       /* Copy vectors to mask ROM indirect addr */
147	adr	r0, _start		/* r0 <- current position of code   */
148		add     r0, r0, #4				/* skip reset vector			*/
149	mov	r2, #64			/* r2 <- size to copy  */
150	add	r2, r0, r2		/* r2 <- source end address	    */
151	mov	r1, #SRAM_OFFSET0	  /* build vect addr */
152	mov	r3, #SRAM_OFFSET1
153	add	r1, r1, r3
154	mov	r3, #SRAM_OFFSET2
155	add	r1, r1, r3
156next:
157	ldmia	r0!, {r3-r10}		/* copy from source address [r0]    */
158	stmia	r1!, {r3-r10}		/* copy to   target address [r1]    */
159	cmp	r0, r2			/* until source end address [r2]    */
160	bne	next			/* loop until equal */
161	bl	cpy_clk_code		/* put dpll adjust code behind vectors */
162#endif
163	/* the mask ROM code should have PLL and others stable */
164#ifndef CONFIG_SKIP_LOWLEVEL_INIT
165	bl  cpu_init_crit
166#endif
167
168/* Set stackpointer in internal RAM to call board_init_f */
169call_board_init_f:
170	ldr	sp, =(CONFIG_SYS_INIT_SP_ADDR)
171	bic	sp, sp, #7 /* 8-byte alignment for ABI compliance */
172	ldr	r0,=0x00000000
173
174	bl	board_init_f
175
176/*------------------------------------------------------------------------------*/
177
178/*
179 * void relocate_code (addr_sp, gd, addr_moni)
180 *
181 * This "function" does not return, instead it continues in RAM
182 * after relocating the monitor code.
183 *
184 */
185	.globl	relocate_code
186relocate_code:
187	mov	r4, r0	/* save addr_sp */
188	mov	r5, r1	/* save addr of gd */
189	mov	r6, r2	/* save addr of destination */
190
191	/* Set up the stack						    */
192stack_setup:
193	mov	sp, r4
194
195	adr	r0, _start
196	cmp	r0, r6
197	moveq	r9, #0		/* no relocation. relocation offset(r9) = 0 */
198	beq	clear_bss		/* skip relocation */
199	mov	r1, r6			/* r1 <- scratch for copy_loop */
200	ldr	r3, _image_copy_end_ofs
201	add	r2, r0, r3		/* r2 <- source end address	    */
202
203copy_loop:
204	ldmia	r0!, {r9-r10}		/* copy from source address [r0]    */
205	stmia	r1!, {r9-r10}		/* copy to   target address [r1]    */
206	cmp	r0, r2			/* until source end address [r2]    */
207	blo	copy_loop
208
209#ifndef CONFIG_SPL_BUILD
210	/*
211	 * fix .rel.dyn relocations
212	 */
213	ldr	r0, _TEXT_BASE		/* r0 <- Text base */
214	sub	r9, r6, r0		/* r9 <- relocation offset */
215	ldr	r10, _dynsym_start_ofs	/* r10 <- sym table ofs */
216	add	r10, r10, r0		/* r10 <- sym table in FLASH */
217	ldr	r2, _rel_dyn_start_ofs	/* r2 <- rel dyn start ofs */
218	add	r2, r2, r0		/* r2 <- rel dyn start in FLASH */
219	ldr	r3, _rel_dyn_end_ofs	/* r3 <- rel dyn end ofs */
220	add	r3, r3, r0		/* r3 <- rel dyn end in FLASH */
221fixloop:
222	ldr	r0, [r2]		/* r0 <- location to fix up, IN FLASH! */
223	add	r0, r0, r9		/* r0 <- location to fix up in RAM */
224	ldr	r1, [r2, #4]
225	and	r7, r1, #0xff
226	cmp	r7, #23			/* relative fixup? */
227	beq	fixrel
228	cmp	r7, #2			/* absolute fixup? */
229	beq	fixabs
230	/* ignore unknown type of fixup */
231	b	fixnext
232fixabs:
233	/* absolute fix: set location to (offset) symbol value */
234	mov	r1, r1, LSR #4		/* r1 <- symbol index in .dynsym */
235	add	r1, r10, r1		/* r1 <- address of symbol in table */
236	ldr	r1, [r1, #4]		/* r1 <- symbol value */
237	add	r1, r1, r9		/* r1 <- relocated sym addr */
238	b	fixnext
239fixrel:
240	/* relative fix: increase location by offset */
241	ldr	r1, [r0]
242	add	r1, r1, r9
243fixnext:
244	str	r1, [r0]
245	add	r2, r2, #8		/* each rel.dyn entry is 8 bytes */
246	cmp	r2, r3
247	blo	fixloop
248	b	clear_bss
249
250_rel_dyn_start_ofs:
251	.word __rel_dyn_start - _start
252_rel_dyn_end_ofs:
253	.word __rel_dyn_end - _start
254_dynsym_start_ofs:
255	.word __dynsym_start - _start
256#endif
257
258clear_bss:
259#ifdef CONFIG_SPL_BUILD
260	/* No relocation for SPL */
261	ldr	r0, =__bss_start
262	ldr	r1, =__bss_end__
263#else
264	ldr	r0, _bss_start_ofs
265	ldr	r1, _bss_end_ofs
266	mov	r4, r6			/* reloc addr */
267	add	r0, r0, r4
268	add	r1, r1, r4
269#endif
270	mov	r2, #0x00000000		/* clear			    */
271
272clbss_l:cmp	r0, r1			/* clear loop... */
273	bhs	clbss_e			/* if reached end of bss, exit */
274	str	r2, [r0]
275	add	r0, r0, #4
276	b	clbss_l
277clbss_e:
278
279/*
280 * We are done. Do not return, instead branch to second part of board
281 * initialization, now running from RAM.
282 */
283#ifdef CONFIG_NAND_SPL
284	ldr     r0, _nand_boot_ofs
285	mov	pc, r0
286
287_nand_boot_ofs:
288	.word nand_boot
289#else
290jump_2_ram:
291	ldr	r0, _board_init_r_ofs
292	adr	r1, _start
293	add	lr, r0, r1
294	add	lr, lr, r9
295	/* setup parameters for board_init_r */
296	mov	r0, r5		/* gd_t */
297	mov	r1, r6		/* dest_addr */
298	/* jump to it ... */
299	mov	pc, lr
300
301_board_init_r_ofs:
302	.word board_init_r - _start
303#endif
304
305/*
306 *************************************************************************
307 *
308 * CPU_init_critical registers
309 *
310 * setup important registers
311 * setup memory timing
312 *
313 *************************************************************************
314 */
315#ifndef CONFIG_SKIP_LOWLEVEL_INIT
316cpu_init_crit:
317	/*
318	 * flush v4 I/D caches
319	 */
320	mov	r0, #0
321	mcr	p15, 0, r0, c7, c7, 0	/* Invalidate I+D+BTB caches */
322	mcr	p15, 0, r0, c8, c7, 0	/* Invalidate Unified TLB */
323
324	/*
325	 * disable MMU stuff and caches
326	 */
327	mrc	p15, 0, r0, c1, c0, 0
328	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
329	bic	r0, r0, #0x00000087	@ clear bits 7, 2:0 (B--- -CAM)
330	orr	r0, r0, #0x00000002	@ set bit 2 (A) Align
331	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-Cache
332	mcr	p15, 0, r0, c1, c0, 0
333
334	/*
335	 * Jump to board specific initialization... The Mask ROM will have already initialized
336	 * basic memory.  Go here to bump up clock rate and handle wake up conditions.
337	 */
338	mov	ip, lr		/* persevere link reg across call */
339	bl	lowlevel_init	/* go setup pll,mux,memory */
340	mov	lr, ip		/* restore link */
341	mov	pc, lr		/* back to my caller */
342#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
343
344#ifndef CONFIG_SPL_BUILD
345/*
346 *************************************************************************
347 *
348 * Interrupt handling
349 *
350 *************************************************************************
351 */
352@
353@ IRQ stack frame.
354@
355#define S_FRAME_SIZE	72
356
357#define S_OLD_R0	68
358#define S_PSR		64
359#define S_PC		60
360#define S_LR		56
361#define S_SP		52
362
363#define S_IP		48
364#define S_FP		44
365#define S_R10		40
366#define S_R9		36
367#define S_R8		32
368#define S_R7		28
369#define S_R6		24
370#define S_R5		20
371#define S_R4		16
372#define S_R3		12
373#define S_R2		8
374#define S_R1		4
375#define S_R0		0
376
377#define MODE_SVC 0x13
378#define I_BIT	 0x80
379
380/*
381 * use bad_save_user_regs for abort/prefetch/undef/swi ...
382 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
383 */
384
385	.macro	bad_save_user_regs
386	sub	sp, sp, #S_FRAME_SIZE		@ carve out a frame on current user stack
387	stmia	sp, {r0 - r12}			@ Save user registers (now in svc mode) r0-r12
388
389	ldr	r2, IRQ_STACK_START_IN		@ set base 2 words into abort stack
390	ldmia	r2, {r2 - r3}			@ get values for "aborted" pc and cpsr (into parm regs)
391	add	r0, sp, #S_FRAME_SIZE		@ grab pointer to old stack
392
393	add	r5, sp, #S_SP
394	mov	r1, lr
395	stmia	r5, {r0 - r3}			@ save sp_SVC, lr_SVC, pc, cpsr
396	mov	r0, sp				@ save current stack into r0 (param register)
397	.endm
398
399	.macro	irq_save_user_regs
400	sub	sp, sp, #S_FRAME_SIZE
401	stmia	sp, {r0 - r12}			@ Calling r0-r12
402	add	r8, sp, #S_PC			@ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
403	stmdb	r8, {sp, lr}^			@ Calling SP, LR
404	str	lr, [r8, #0]			@ Save calling PC
405	mrs	r6, spsr
406	str	r6, [r8, #4]			@ Save CPSR
407	str	r0, [r8, #8]			@ Save OLD_R0
408	mov	r0, sp
409	.endm
410
411	.macro	irq_restore_user_regs
412	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
413	mov	r0, r0
414	ldr	lr, [sp, #S_PC]			@ Get PC
415	add	sp, sp, #S_FRAME_SIZE
416	subs	pc, lr, #4			@ return & move spsr_svc into cpsr
417	.endm
418
419	.macro get_bad_stack
420	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack (enter in banked mode)
421
422	str	lr, [r13]			@ save caller lr in position 0 of saved stack
423	mrs	lr, spsr			@ get the spsr
424	str	lr, [r13, #4]			@ save spsr in position 1 of saved stack
425
426	mov	r13, #MODE_SVC			@ prepare SVC-Mode
427	@ msr	spsr_c, r13
428	msr	spsr, r13			@ switch modes, make sure moves will execute
429	mov	lr, pc				@ capture return pc
430	movs	pc, lr				@ jump to next instruction & switch modes.
431	.endm
432
433	.macro get_bad_stack_swi
434	sub	r13, r13, #4			@ space on current stack for scratch reg.
435	str	r0, [r13]			@ save R0's value.
436	ldr	r0, IRQ_STACK_START_IN		@ get data regions start
437	str	lr, [r0]			@ save caller lr in position 0 of saved stack
438	mrs	r0, spsr			@ get the spsr
439	str	lr, [r0, #4]			@ save spsr in position 1 of saved stack
440	ldr	r0, [r13]			@ restore r0
441	add	r13, r13, #4			@ pop stack entry
442	.endm
443
444	.macro get_irq_stack			@ setup IRQ stack
445	ldr	sp, IRQ_STACK_START
446	.endm
447
448	.macro get_fiq_stack			@ setup FIQ stack
449	ldr	sp, FIQ_STACK_START
450	.endm
451#endif	/* CONFIG_SPL_BUILD */
452
453/*
454 * exception handlers
455 */
456#ifdef CONFIG_SPL_BUILD
457	.align	5
458do_hang:
459	ldr	sp, _TEXT_BASE			/* use 32 words about stack */
460	bl	hang				/* hang and never return */
461#else	/* !CONFIG_SPL_BUILD */
462	.align	5
463undefined_instruction:
464	get_bad_stack
465	bad_save_user_regs
466	bl	do_undefined_instruction
467
468	.align	5
469software_interrupt:
470	get_bad_stack_swi
471	bad_save_user_regs
472	bl	do_software_interrupt
473
474	.align	5
475prefetch_abort:
476	get_bad_stack
477	bad_save_user_regs
478	bl	do_prefetch_abort
479
480	.align	5
481data_abort:
482	get_bad_stack
483	bad_save_user_regs
484	bl	do_data_abort
485
486	.align	5
487not_used:
488	get_bad_stack
489	bad_save_user_regs
490	bl	do_not_used
491
492#ifdef CONFIG_USE_IRQ
493
494	.align	5
495irq:
496	get_irq_stack
497	irq_save_user_regs
498	bl	do_irq
499	irq_restore_user_regs
500
501	.align	5
502fiq:
503	get_fiq_stack
504	/* someone ought to write a more effiction fiq_save_user_regs */
505	irq_save_user_regs
506	bl	do_fiq
507	irq_restore_user_regs
508
509#else
510
511	.align	5
512irq:
513	get_bad_stack
514	bad_save_user_regs
515	bl	do_irq
516
517	.align	5
518fiq:
519	get_bad_stack
520	bad_save_user_regs
521	bl	do_fiq
522
523#endif
524	.align 5
525.global arm1136_cache_flush
526arm1136_cache_flush:
527#if !defined(CONFIG_SYS_ICACHE_OFF)
528		mcr	p15, 0, r1, c7, c5, 0	@ invalidate I cache
529#endif
530#if !defined(CONFIG_SYS_DCACHE_OFF)
531		mcr	p15, 0, r1, c7, c14, 0	@ invalidate D cache
532#endif
533		mov	pc, lr			@ back to caller
534#endif	/* CONFIG_SPL_BUILD */
535