xref: /openbmc/u-boot/arch/arm/cpu/arm1136/start.S (revision 5d27e02c)
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#ifdef CONFIG_USE_IRQ
108/* IRQ stack memory (calculated at run-time) */
109.globl IRQ_STACK_START
110IRQ_STACK_START:
111	.word	0x0badc0de
112
113/* IRQ stack memory (calculated at run-time) */
114.globl FIQ_STACK_START
115FIQ_STACK_START:
116	.word 0x0badc0de
117#endif
118
119/* IRQ stack memory (calculated at run-time) + 8 bytes */
120.globl IRQ_STACK_START_IN
121IRQ_STACK_START_IN:
122	.word	0x0badc0de
123
124/*
125 * the actual reset code
126 */
127
128reset:
129	/*
130	 * set the cpu to SVC32 mode
131	 */
132	mrs	r0,cpsr
133	bic	r0,r0,#0x1f
134	orr	r0,r0,#0xd3
135	msr	cpsr,r0
136
137#ifdef CONFIG_OMAP2420H4
138       /* Copy vectors to mask ROM indirect addr */
139	adr	r0, _start		/* r0 <- current position of code   */
140		add     r0, r0, #4				/* skip reset vector			*/
141	mov	r2, #64			/* r2 <- size to copy  */
142	add	r2, r0, r2		/* r2 <- source end address	    */
143	mov	r1, #SRAM_OFFSET0	  /* build vect addr */
144	mov	r3, #SRAM_OFFSET1
145	add	r1, r1, r3
146	mov	r3, #SRAM_OFFSET2
147	add	r1, r1, r3
148next:
149	ldmia	r0!, {r3-r10}		/* copy from source address [r0]    */
150	stmia	r1!, {r3-r10}		/* copy to   target address [r1]    */
151	cmp	r0, r2			/* until source end address [r2]    */
152	bne	next			/* loop until equal */
153	bl	cpy_clk_code		/* put dpll adjust code behind vectors */
154#endif
155	/* the mask ROM code should have PLL and others stable */
156#ifndef CONFIG_SKIP_LOWLEVEL_INIT
157	bl  cpu_init_crit
158#endif
159
160/* Set stackpointer in internal RAM to call board_init_f */
161call_board_init_f:
162	ldr	sp, =(CONFIG_SYS_INIT_SP_ADDR)
163	bic	sp, sp, #7 /* 8-byte alignment for ABI compliance */
164	ldr	r0,=0x00000000
165
166#ifdef CONFIG_NAND_SPL
167	bl	nand_boot
168#else
169#ifdef CONFIG_ONENAND_IPL
170	bl	start_oneboot
171#else
172	bl	board_init_f
173#endif /* CONFIG_ONENAND_IPL */
174#endif /* CONFIG_NAND_SPL */
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	beq	clear_bss		/* skip relocation */
198	mov	r1, r6			/* r1 <- scratch for copy_loop */
199	ldr	r2, _TEXT_BASE
200	ldr	r3, _bss_start_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_PRELOADER
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#endif
249
250clear_bss:
251#ifndef CONFIG_PRELOADER
252	ldr	r0, _bss_start_ofs
253	ldr	r1, _bss_end_ofs
254	ldr	r3, _TEXT_BASE		/* Text base */
255	mov	r4, r6			/* reloc addr */
256	add	r0, r0, r4
257	add	r1, r1, r4
258	mov	r2, #0x00000000		/* clear			    */
259
260clbss_l:str	r2, [r0]		/* clear loop...		    */
261	add	r0, r0, #4
262	cmp	r0, r1
263	bne	clbss_l
264#endif	/* #ifndef CONFIG_PRELOADER */
265
266/*
267 * We are done. Do not return, instead branch to second part of board
268 * initialization, now running from RAM.
269 */
270#ifdef CONFIG_NAND_SPL
271	ldr     r0, _nand_boot_ofs
272	adr	r1, _start
273	add	pc, r0, r1
274_nand_boot_ofs
275	: .word nand_boot - _start
276#else
277jump_2_ram:
278	ldr	r0, _board_init_r_ofs
279	adr	r1, _start
280	add	lr, r0, r1
281	add	lr, lr, r9
282	/* setup parameters for board_init_r */
283	mov	r0, r5		/* gd_t */
284	mov	r1, r6		/* dest_addr */
285	/* jump to it ... */
286	mov	pc, lr
287
288_board_init_r_ofs:
289	.word board_init_r - _start
290#endif
291
292_rel_dyn_start_ofs:
293	.word __rel_dyn_start - _start
294_rel_dyn_end_ofs:
295	.word __rel_dyn_end - _start
296_dynsym_start_ofs:
297	.word __dynsym_start - _start
298
299/*
300 *************************************************************************
301 *
302 * CPU_init_critical registers
303 *
304 * setup important registers
305 * setup memory timing
306 *
307 *************************************************************************
308 */
309#ifndef CONFIG_SKIP_LOWLEVEL_INIT
310cpu_init_crit:
311	/*
312	 * flush v4 I/D caches
313	 */
314	mov	r0, #0
315	mcr	p15, 0, r0, c7, c7, 0	/* Invalidate I+D+BTB caches */
316	mcr	p15, 0, r0, c8, c7, 0	/* Invalidate Unified TLB */
317
318	/*
319	 * disable MMU stuff and caches
320	 */
321	mrc	p15, 0, r0, c1, c0, 0
322	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
323	bic	r0, r0, #0x00000087	@ clear bits 7, 2:0 (B--- -CAM)
324	orr	r0, r0, #0x00000002	@ set bit 2 (A) Align
325	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-Cache
326	mcr	p15, 0, r0, c1, c0, 0
327
328	/*
329	 * Jump to board specific initialization... The Mask ROM will have already initialized
330	 * basic memory.  Go here to bump up clock rate and handle wake up conditions.
331	 */
332	mov	ip, lr		/* persevere link reg across call */
333	bl	lowlevel_init	/* go setup pll,mux,memory */
334	mov	lr, ip		/* restore link */
335	mov	pc, lr		/* back to my caller */
336#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
337
338#ifndef CONFIG_PRELOADER
339/*
340 *************************************************************************
341 *
342 * Interrupt handling
343 *
344 *************************************************************************
345 */
346@
347@ IRQ stack frame.
348@
349#define S_FRAME_SIZE	72
350
351#define S_OLD_R0	68
352#define S_PSR		64
353#define S_PC		60
354#define S_LR		56
355#define S_SP		52
356
357#define S_IP		48
358#define S_FP		44
359#define S_R10		40
360#define S_R9		36
361#define S_R8		32
362#define S_R7		28
363#define S_R6		24
364#define S_R5		20
365#define S_R4		16
366#define S_R3		12
367#define S_R2		8
368#define S_R1		4
369#define S_R0		0
370
371#define MODE_SVC 0x13
372#define I_BIT	 0x80
373
374/*
375 * use bad_save_user_regs for abort/prefetch/undef/swi ...
376 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
377 */
378
379	.macro	bad_save_user_regs
380	sub	sp, sp, #S_FRAME_SIZE		@ carve out a frame on current user stack
381	stmia	sp, {r0 - r12}			@ Save user registers (now in svc mode) r0-r12
382
383	ldr	r2, IRQ_STACK_START_IN		@ set base 2 words into abort stack
384	ldmia	r2, {r2 - r3}			@ get values for "aborted" pc and cpsr (into parm regs)
385	add	r0, sp, #S_FRAME_SIZE		@ grab pointer to old stack
386
387	add	r5, sp, #S_SP
388	mov	r1, lr
389	stmia	r5, {r0 - r3}			@ save sp_SVC, lr_SVC, pc, cpsr
390	mov	r0, sp				@ save current stack into r0 (param register)
391	.endm
392
393	.macro	irq_save_user_regs
394	sub	sp, sp, #S_FRAME_SIZE
395	stmia	sp, {r0 - r12}			@ Calling r0-r12
396	add	r8, sp, #S_PC			@ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
397	stmdb	r8, {sp, lr}^			@ Calling SP, LR
398	str	lr, [r8, #0]			@ Save calling PC
399	mrs	r6, spsr
400	str	r6, [r8, #4]			@ Save CPSR
401	str	r0, [r8, #8]			@ Save OLD_R0
402	mov	r0, sp
403	.endm
404
405	.macro	irq_restore_user_regs
406	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
407	mov	r0, r0
408	ldr	lr, [sp, #S_PC]			@ Get PC
409	add	sp, sp, #S_FRAME_SIZE
410	subs	pc, lr, #4			@ return & move spsr_svc into cpsr
411	.endm
412
413	.macro get_bad_stack
414	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack (enter in banked mode)
415
416	str	lr, [r13]			@ save caller lr in position 0 of saved stack
417	mrs	lr, spsr			@ get the spsr
418	str	lr, [r13, #4]			@ save spsr in position 1 of saved stack
419
420	mov	r13, #MODE_SVC			@ prepare SVC-Mode
421	@ msr	spsr_c, r13
422	msr	spsr, r13			@ switch modes, make sure moves will execute
423	mov	lr, pc				@ capture return pc
424	movs	pc, lr				@ jump to next instruction & switch modes.
425	.endm
426
427	.macro get_bad_stack_swi
428	sub	r13, r13, #4			@ space on current stack for scratch reg.
429	str	r0, [r13]			@ save R0's value.
430	ldr	r0, IRQ_STACK_START_IN		@ get data regions start
431	str	lr, [r0]			@ save caller lr in position 0 of saved stack
432	mrs	r0, spsr			@ get the spsr
433	str	lr, [r0, #4]			@ save spsr in position 1 of saved stack
434	ldr	r0, [r13]			@ restore r0
435	add	r13, r13, #4			@ pop stack entry
436	.endm
437
438	.macro get_irq_stack			@ setup IRQ stack
439	ldr	sp, IRQ_STACK_START
440	.endm
441
442	.macro get_fiq_stack			@ setup FIQ stack
443	ldr	sp, FIQ_STACK_START
444	.endm
445#endif	/* CONFIG_PRELOADER */
446
447/*
448 * exception handlers
449 */
450#ifdef CONFIG_PRELOADER
451	.align	5
452do_hang:
453	ldr	sp, _TEXT_BASE			/* use 32 words about stack */
454	bl	hang				/* hang and never return */
455#else	/* !CONFIG_PRELOADER */
456	.align	5
457undefined_instruction:
458	get_bad_stack
459	bad_save_user_regs
460	bl	do_undefined_instruction
461
462	.align	5
463software_interrupt:
464	get_bad_stack_swi
465	bad_save_user_regs
466	bl	do_software_interrupt
467
468	.align	5
469prefetch_abort:
470	get_bad_stack
471	bad_save_user_regs
472	bl	do_prefetch_abort
473
474	.align	5
475data_abort:
476	get_bad_stack
477	bad_save_user_regs
478	bl	do_data_abort
479
480	.align	5
481not_used:
482	get_bad_stack
483	bad_save_user_regs
484	bl	do_not_used
485
486#ifdef CONFIG_USE_IRQ
487
488	.align	5
489irq:
490	get_irq_stack
491	irq_save_user_regs
492	bl	do_irq
493	irq_restore_user_regs
494
495	.align	5
496fiq:
497	get_fiq_stack
498	/* someone ought to write a more effiction fiq_save_user_regs */
499	irq_save_user_regs
500	bl	do_fiq
501	irq_restore_user_regs
502
503#else
504
505	.align	5
506irq:
507	get_bad_stack
508	bad_save_user_regs
509	bl	do_irq
510
511	.align	5
512fiq:
513	get_bad_stack
514	bad_save_user_regs
515	bl	do_fiq
516
517#endif
518	.align 5
519.global arm1136_cache_flush
520arm1136_cache_flush:
521#if !defined(CONFIG_SYS_NO_ICACHE)
522		mcr	p15, 0, r1, c7, c5, 0	@ invalidate I cache
523#endif
524#if !defined(CONFIG_SYS_NO_DCACHE)
525		mcr	p15, 0, r1, c7, c14, 0	@ invalidate D cache
526#endif
527		mov	pc, lr			@ back to caller
528#endif	/* CONFIG_PRELOADER */
529