xref: /openbmc/u-boot/arch/arm/cpu/arm1136/start.S (revision 9b107e6138e719ea5a0b924862a9b109c020c7ac)
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 Gr�ger <mag@sysgo.de>
7 *  Copyright (c) 2002	Alex Z�pke <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_PRELOADER
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_PRELOADER */
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.globl _bss_end_ofs
104_bss_end_ofs:
105	.word _end - _start
106
107.globl _datarel_start_ofs
108_datarel_start_ofs:
109	.word __datarel_start - _start
110
111.globl _datarelrolocal_start_ofs
112_datarelrolocal_start_ofs:
113	.word __datarelrolocal_start - _start
114
115.globl _datarellocal_start_ofs
116_datarellocal_start_ofs:
117	.word __datarellocal_start - _start
118
119.globl _datarelro_start_ofs
120_datarelro_start_ofs:
121	.word __datarelro_start - _start
122
123#ifdef CONFIG_USE_IRQ
124/* IRQ stack memory (calculated at run-time) */
125.globl IRQ_STACK_START
126IRQ_STACK_START:
127	.word	0x0badc0de
128
129/* IRQ stack memory (calculated at run-time) */
130.globl FIQ_STACK_START
131FIQ_STACK_START:
132	.word 0x0badc0de
133#endif
134
135/* IRQ stack memory (calculated at run-time) + 8 bytes */
136.globl IRQ_STACK_START_IN
137IRQ_STACK_START_IN:
138	.word	0x0badc0de
139
140/*
141 * the actual reset code
142 */
143
144reset:
145	/*
146	 * set the cpu to SVC32 mode
147	 */
148	mrs	r0,cpsr
149	bic	r0,r0,#0x1f
150	orr	r0,r0,#0xd3
151	msr	cpsr,r0
152
153#ifdef CONFIG_OMAP2420H4
154       /* Copy vectors to mask ROM indirect addr */
155	adr	r0, _start		/* r0 <- current position of code   */
156		add     r0, r0, #4				/* skip reset vector			*/
157	mov	r2, #64			/* r2 <- size to copy  */
158	add	r2, r0, r2		/* r2 <- source end address	    */
159	mov	r1, #SRAM_OFFSET0	  /* build vect addr */
160	mov	r3, #SRAM_OFFSET1
161	add	r1, r1, r3
162	mov	r3, #SRAM_OFFSET2
163	add	r1, r1, r3
164next:
165	ldmia	r0!, {r3-r10}		/* copy from source address [r0]    */
166	stmia	r1!, {r3-r10}		/* copy to   target address [r1]    */
167	cmp	r0, r2			/* until source end address [r2]    */
168	bne	next			/* loop until equal */
169	bl	cpy_clk_code		/* put dpll adjust code behind vectors */
170#endif
171	/* the mask ROM code should have PLL and others stable */
172#ifndef CONFIG_SKIP_LOWLEVEL_INIT
173	bl  cpu_init_crit
174#endif
175
176/* Set stackpointer in internal RAM to call board_init_f */
177call_board_init_f:
178	ldr	sp, =(CONFIG_SYS_INIT_SP_ADDR)
179	ldr	r0,=0x00000000
180
181#ifdef CONFIG_NAND_SPL
182	bl	nand_boot
183#else
184#ifdef CONFIG_ONENAND_IPL
185	bl	start_oneboot
186#else
187	bl	board_init_f
188#endif /* CONFIG_ONENAND_IPL */
189#endif /* CONFIG_NAND_SPL */
190
191/*------------------------------------------------------------------------------*/
192
193/*
194 * void relocate_code (addr_sp, gd, addr_moni)
195 *
196 * This "function" does not return, instead it continues in RAM
197 * after relocating the monitor code.
198 *
199 */
200	.globl	relocate_code
201relocate_code:
202	mov	r4, r0	/* save addr_sp */
203	mov	r5, r1	/* save addr of gd */
204	mov	r6, r2	/* save addr of destination */
205	mov	r7, r2	/* save addr of destination */
206
207	/* Set up the stack						    */
208stack_setup:
209	mov	sp, r4
210
211	adr	r0, _start
212	ldr	r2, _TEXT_BASE
213	ldr	r3, _bss_start_ofs
214	add	r2, r0, r3		/* r2 <- source end address	    */
215	cmp	r0, r6
216	beq	clear_bss
217
218copy_loop:
219	ldmia	r0!, {r9-r10}		/* copy from source address [r0]    */
220	stmia	r6!, {r9-r10}		/* copy to   target address [r1]    */
221	cmp	r0, r2			/* until source end address [r2]    */
222	blo	copy_loop
223
224#ifndef CONFIG_PRELOADER
225	/*
226	 * fix .rel.dyn relocations
227	 */
228	ldr	r0, _TEXT_BASE		/* r0 <- Text base */
229	sub	r9, r7, r0		/* r9 <- relocation offset */
230	ldr	r10, _dynsym_start_ofs	/* r10 <- sym table ofs */
231	add	r10, r10, r0		/* r10 <- sym table in FLASH */
232	ldr	r2, _rel_dyn_start_ofs	/* r2 <- rel dyn start ofs */
233	add	r2, r2, r0		/* r2 <- rel dyn start in FLASH */
234	ldr	r3, _rel_dyn_end_ofs	/* r3 <- rel dyn end ofs */
235	add	r3, r3, r0		/* r3 <- rel dyn end in FLASH */
236fixloop:
237	ldr	r0, [r2]		/* r0 <- location to fix up, IN FLASH! */
238	add	r0, r0, r9		/* r0 <- location to fix up in RAM */
239	ldr	r1, [r2, #4]
240	and	r8, r1, #0xff
241	cmp	r8, #23			/* relative fixup? */
242	beq	fixrel
243	cmp	r8, #2			/* absolute fixup? */
244	beq	fixabs
245	/* ignore unknown type of fixup */
246	b	fixnext
247fixabs:
248	/* absolute fix: set location to (offset) symbol value */
249	mov	r1, r1, LSR #4		/* r1 <- symbol index in .dynsym */
250	add	r1, r10, r1		/* r1 <- address of symbol in table */
251	ldr	r1, [r1, #4]		/* r1 <- symbol value */
252	add	r1, r9			/* r1 <- relocated sym addr */
253	b	fixnext
254fixrel:
255	/* relative fix: increase location by offset */
256	ldr	r1, [r0]
257	add	r1, r1, r9
258fixnext:
259	str	r1, [r0]
260	add	r2, r2, #8		/* each rel.dyn entry is 8 bytes */
261	cmp	r2, r3
262	blo	fixloop
263#endif
264
265clear_bss:
266#ifndef CONFIG_PRELOADER
267	ldr	r0, _bss_start_ofs
268	ldr	r1, _bss_end_ofs
269	ldr	r3, _TEXT_BASE		/* Text base */
270	mov	r4, r7			/* reloc addr */
271	add	r0, r0, r4
272	add	r1, r1, r4
273	mov	r2, #0x00000000		/* clear			    */
274
275clbss_l:str	r2, [r0]		/* clear loop...		    */
276	add	r0, r0, #4
277	cmp	r0, r1
278	bne	clbss_l
279#endif	/* #ifndef CONFIG_PRELOADER */
280
281/*
282 * We are done. Do not return, instead branch to second part of board
283 * initialization, now running from RAM.
284 */
285#ifdef CONFIG_NAND_SPL
286	ldr     r0, _nand_boot_ofs
287	adr	r1, _start
288	add	pc, r0, r1
289_nand_boot_ofs
290	: .word nand_boot - _start
291#else
292jump_2_ram:
293	ldr	r0, _board_init_r_ofs
294	adr	r1, _start
295	add	lr, r0, r1
296	add	lr, lr, r9
297	/* setup parameters for board_init_r */
298	mov	r0, r5		/* gd_t */
299	mov	r1, r7		/* dest_addr */
300	/* jump to it ... */
301	mov	pc, lr
302
303_board_init_r_ofs:
304	.word board_init_r - _start
305#endif
306
307_rel_dyn_start_ofs:
308	.word __rel_dyn_start - _start
309_rel_dyn_end_ofs:
310	.word __rel_dyn_end - _start
311_dynsym_start_ofs:
312	.word __dynsym_start - _start
313
314/*
315 *************************************************************************
316 *
317 * CPU_init_critical registers
318 *
319 * setup important registers
320 * setup memory timing
321 *
322 *************************************************************************
323 */
324#ifndef CONFIG_SKIP_LOWLEVEL_INIT
325cpu_init_crit:
326	/*
327	 * flush v4 I/D caches
328	 */
329	mov	r0, #0
330	mcr	p15, 0, r0, c7, c7, 0	/* Invalidate I+D+BTB caches */
331	mcr	p15, 0, r0, c8, c7, 0	/* Invalidate Unified TLB */
332
333	/*
334	 * disable MMU stuff and caches
335	 */
336	mrc	p15, 0, r0, c1, c0, 0
337	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
338	bic	r0, r0, #0x00000087	@ clear bits 7, 2:0 (B--- -CAM)
339	orr	r0, r0, #0x00000002	@ set bit 2 (A) Align
340	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-Cache
341	mcr	p15, 0, r0, c1, c0, 0
342
343	/*
344	 * Jump to board specific initialization... The Mask ROM will have already initialized
345	 * basic memory.  Go here to bump up clock rate and handle wake up conditions.
346	 */
347	mov	ip, lr		/* persevere link reg across call */
348	bl	lowlevel_init	/* go setup pll,mux,memory */
349	mov	lr, ip		/* restore link */
350	mov	pc, lr		/* back to my caller */
351#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
352
353#ifndef CONFIG_PRELOADER
354/*
355 *************************************************************************
356 *
357 * Interrupt handling
358 *
359 *************************************************************************
360 */
361@
362@ IRQ stack frame.
363@
364#define S_FRAME_SIZE	72
365
366#define S_OLD_R0	68
367#define S_PSR		64
368#define S_PC		60
369#define S_LR		56
370#define S_SP		52
371
372#define S_IP		48
373#define S_FP		44
374#define S_R10		40
375#define S_R9		36
376#define S_R8		32
377#define S_R7		28
378#define S_R6		24
379#define S_R5		20
380#define S_R4		16
381#define S_R3		12
382#define S_R2		8
383#define S_R1		4
384#define S_R0		0
385
386#define MODE_SVC 0x13
387#define I_BIT	 0x80
388
389/*
390 * use bad_save_user_regs for abort/prefetch/undef/swi ...
391 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
392 */
393
394	.macro	bad_save_user_regs
395	sub	sp, sp, #S_FRAME_SIZE		@ carve out a frame on current user stack
396	stmia	sp, {r0 - r12}			@ Save user registers (now in svc mode) r0-r12
397
398	ldr	r2, IRQ_STACK_START_IN		@ set base 2 words into abort stack
399	ldmia	r2, {r2 - r3}			@ get values for "aborted" pc and cpsr (into parm regs)
400	add	r0, sp, #S_FRAME_SIZE		@ grab pointer to old stack
401
402	add	r5, sp, #S_SP
403	mov	r1, lr
404	stmia	r5, {r0 - r3}			@ save sp_SVC, lr_SVC, pc, cpsr
405	mov	r0, sp				@ save current stack into r0 (param register)
406	.endm
407
408	.macro	irq_save_user_regs
409	sub	sp, sp, #S_FRAME_SIZE
410	stmia	sp, {r0 - r12}			@ Calling r0-r12
411	add	r8, sp, #S_PC			@ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
412	stmdb	r8, {sp, lr}^			@ Calling SP, LR
413	str	lr, [r8, #0]			@ Save calling PC
414	mrs	r6, spsr
415	str	r6, [r8, #4]			@ Save CPSR
416	str	r0, [r8, #8]			@ Save OLD_R0
417	mov	r0, sp
418	.endm
419
420	.macro	irq_restore_user_regs
421	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
422	mov	r0, r0
423	ldr	lr, [sp, #S_PC]			@ Get PC
424	add	sp, sp, #S_FRAME_SIZE
425	subs	pc, lr, #4			@ return & move spsr_svc into cpsr
426	.endm
427
428	.macro get_bad_stack
429	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack (enter in banked mode)
430
431	str	lr, [r13]			@ save caller lr in position 0 of saved stack
432	mrs	lr, spsr			@ get the spsr
433	str	lr, [r13, #4]			@ save spsr in position 1 of saved stack
434
435	mov	r13, #MODE_SVC			@ prepare SVC-Mode
436	@ msr	spsr_c, r13
437	msr	spsr, r13			@ switch modes, make sure moves will execute
438	mov	lr, pc				@ capture return pc
439	movs	pc, lr				@ jump to next instruction & switch modes.
440	.endm
441
442	.macro get_bad_stack_swi
443	sub	r13, r13, #4			@ space on current stack for scratch reg.
444	str	r0, [r13]			@ save R0's value.
445	ldr	r0, IRQ_STACK_START_IN		@ get data regions start
446	str	lr, [r0]			@ save caller lr in position 0 of saved stack
447	mrs	r0, spsr			@ get the spsr
448	str	lr, [r0, #4]			@ save spsr in position 1 of saved stack
449	ldr	r0, [r13]			@ restore r0
450	add	r13, r13, #4			@ pop stack entry
451	.endm
452
453	.macro get_irq_stack			@ setup IRQ stack
454	ldr	sp, IRQ_STACK_START
455	.endm
456
457	.macro get_fiq_stack			@ setup FIQ stack
458	ldr	sp, FIQ_STACK_START
459	.endm
460#endif	/* CONFIG_PRELOADER */
461
462/*
463 * exception handlers
464 */
465#ifdef CONFIG_PRELOADER
466	.align	5
467do_hang:
468	ldr	sp, _TEXT_BASE			/* use 32 words about stack */
469	bl	hang				/* hang and never return */
470#else	/* !CONFIG_PRELOADER */
471	.align	5
472undefined_instruction:
473	get_bad_stack
474	bad_save_user_regs
475	bl	do_undefined_instruction
476
477	.align	5
478software_interrupt:
479	get_bad_stack_swi
480	bad_save_user_regs
481	bl	do_software_interrupt
482
483	.align	5
484prefetch_abort:
485	get_bad_stack
486	bad_save_user_regs
487	bl	do_prefetch_abort
488
489	.align	5
490data_abort:
491	get_bad_stack
492	bad_save_user_regs
493	bl	do_data_abort
494
495	.align	5
496not_used:
497	get_bad_stack
498	bad_save_user_regs
499	bl	do_not_used
500
501#ifdef CONFIG_USE_IRQ
502
503	.align	5
504irq:
505	get_irq_stack
506	irq_save_user_regs
507	bl	do_irq
508	irq_restore_user_regs
509
510	.align	5
511fiq:
512	get_fiq_stack
513	/* someone ought to write a more effiction fiq_save_user_regs */
514	irq_save_user_regs
515	bl	do_fiq
516	irq_restore_user_regs
517
518#else
519
520	.align	5
521irq:
522	get_bad_stack
523	bad_save_user_regs
524	bl	do_irq
525
526	.align	5
527fiq:
528	get_bad_stack
529	bad_save_user_regs
530	bl	do_fiq
531
532#endif
533	.align 5
534.global arm1136_cache_flush
535arm1136_cache_flush:
536#if !defined(CONFIG_SYS_NO_ICACHE)
537		mcr	p15, 0, r1, c7, c5, 0	@ invalidate I cache
538#endif
539#if !defined(CONFIG_SYS_NO_DCACHE)
540		mcr	p15, 0, r1, c7, c14, 0	@ invalidate D cache
541#endif
542		mov	pc, lr			@ back to caller
543#endif	/* CONFIG_PRELOADER */
544