xref: /openbmc/u-boot/arch/arm/cpu/arm1136/start.S (revision 92faa8b1)
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.globl _bss_end_ofs
104_bss_end_ofs:
105	.word __bss_end__ - _start
106
107.globl _end_ofs
108_end_ofs:
109	.word _end - _start
110
111#ifdef CONFIG_USE_IRQ
112/* IRQ stack memory (calculated at run-time) */
113.globl IRQ_STACK_START
114IRQ_STACK_START:
115	.word	0x0badc0de
116
117/* IRQ stack memory (calculated at run-time) */
118.globl FIQ_STACK_START
119FIQ_STACK_START:
120	.word 0x0badc0de
121#endif
122
123/* IRQ stack memory (calculated at run-time) + 8 bytes */
124.globl IRQ_STACK_START_IN
125IRQ_STACK_START_IN:
126	.word	0x0badc0de
127
128/*
129 * the actual reset code
130 */
131
132reset:
133	/*
134	 * set the cpu to SVC32 mode
135	 */
136	mrs	r0,cpsr
137	bic	r0,r0,#0x1f
138	orr	r0,r0,#0xd3
139	msr	cpsr,r0
140
141#ifdef CONFIG_OMAP2420H4
142       /* Copy vectors to mask ROM indirect addr */
143	adr	r0, _start		/* r0 <- current position of code   */
144		add     r0, r0, #4				/* skip reset vector			*/
145	mov	r2, #64			/* r2 <- size to copy  */
146	add	r2, r0, r2		/* r2 <- source end address	    */
147	mov	r1, #SRAM_OFFSET0	  /* build vect addr */
148	mov	r3, #SRAM_OFFSET1
149	add	r1, r1, r3
150	mov	r3, #SRAM_OFFSET2
151	add	r1, r1, r3
152next:
153	ldmia	r0!, {r3-r10}		/* copy from source address [r0]    */
154	stmia	r1!, {r3-r10}		/* copy to   target address [r1]    */
155	cmp	r0, r2			/* until source end address [r2]    */
156	bne	next			/* loop until equal */
157	bl	cpy_clk_code		/* put dpll adjust code behind vectors */
158#endif
159	/* the mask ROM code should have PLL and others stable */
160#ifndef CONFIG_SKIP_LOWLEVEL_INIT
161	bl  cpu_init_crit
162#endif
163
164/* Set stackpointer in internal RAM to call board_init_f */
165call_board_init_f:
166	ldr	sp, =(CONFIG_SYS_INIT_SP_ADDR)
167	bic	sp, sp, #7 /* 8-byte alignment for ABI compliance */
168	ldr	r0,=0x00000000
169
170	bl	board_init_f
171
172/*------------------------------------------------------------------------------*/
173
174/*
175 * void relocate_code (addr_sp, gd, addr_moni)
176 *
177 * This "function" does not return, instead it continues in RAM
178 * after relocating the monitor code.
179 *
180 */
181	.globl	relocate_code
182relocate_code:
183	mov	r4, r0	/* save addr_sp */
184	mov	r5, r1	/* save addr of gd */
185	mov	r6, r2	/* save addr of destination */
186
187	/* Set up the stack						    */
188stack_setup:
189	mov	sp, r4
190
191	adr	r0, _start
192	cmp	r0, r6
193	beq	clear_bss		/* skip relocation */
194	mov	r1, r6			/* r1 <- scratch for copy_loop */
195	ldr	r3, _bss_start_ofs
196	add	r2, r0, r3		/* r2 <- source end address	    */
197
198copy_loop:
199	ldmia	r0!, {r9-r10}		/* copy from source address [r0]    */
200	stmia	r1!, {r9-r10}		/* copy to   target address [r1]    */
201	cmp	r0, r2			/* until source end address [r2]    */
202	blo	copy_loop
203
204#ifndef CONFIG_SPL_BUILD
205	/*
206	 * fix .rel.dyn relocations
207	 */
208	ldr	r0, _TEXT_BASE		/* r0 <- Text base */
209	sub	r9, r6, r0		/* r9 <- relocation offset */
210	ldr	r10, _dynsym_start_ofs	/* r10 <- sym table ofs */
211	add	r10, r10, r0		/* r10 <- sym table in FLASH */
212	ldr	r2, _rel_dyn_start_ofs	/* r2 <- rel dyn start ofs */
213	add	r2, r2, r0		/* r2 <- rel dyn start in FLASH */
214	ldr	r3, _rel_dyn_end_ofs	/* r3 <- rel dyn end ofs */
215	add	r3, r3, r0		/* r3 <- rel dyn end in FLASH */
216fixloop:
217	ldr	r0, [r2]		/* r0 <- location to fix up, IN FLASH! */
218	add	r0, r0, r9		/* r0 <- location to fix up in RAM */
219	ldr	r1, [r2, #4]
220	and	r7, r1, #0xff
221	cmp	r7, #23			/* relative fixup? */
222	beq	fixrel
223	cmp	r7, #2			/* absolute fixup? */
224	beq	fixabs
225	/* ignore unknown type of fixup */
226	b	fixnext
227fixabs:
228	/* absolute fix: set location to (offset) symbol value */
229	mov	r1, r1, LSR #4		/* r1 <- symbol index in .dynsym */
230	add	r1, r10, r1		/* r1 <- address of symbol in table */
231	ldr	r1, [r1, #4]		/* r1 <- symbol value */
232	add	r1, r1, r9		/* r1 <- relocated sym addr */
233	b	fixnext
234fixrel:
235	/* relative fix: increase location by offset */
236	ldr	r1, [r0]
237	add	r1, r1, r9
238fixnext:
239	str	r1, [r0]
240	add	r2, r2, #8		/* each rel.dyn entry is 8 bytes */
241	cmp	r2, r3
242	blo	fixloop
243#endif
244
245clear_bss:
246#ifndef CONFIG_SPL_BUILD
247	ldr	r0, _bss_start_ofs
248	ldr	r1, _bss_end_ofs
249	mov	r4, r6			/* reloc addr */
250	add	r0, r0, r4
251	add	r1, r1, r4
252	mov	r2, #0x00000000		/* clear			    */
253
254clbss_l:str	r2, [r0]		/* clear loop...		    */
255	add	r0, r0, #4
256	cmp	r0, r1
257	bne	clbss_l
258#endif	/* #ifndef CONFIG_SPL_BUILD */
259
260/*
261 * We are done. Do not return, instead branch to second part of board
262 * initialization, now running from RAM.
263 */
264#ifdef CONFIG_NAND_SPL
265	ldr     r0, _nand_boot_ofs
266	mov	pc, r0
267
268_nand_boot_ofs:
269	.word nand_boot
270#else
271jump_2_ram:
272	ldr	r0, _board_init_r_ofs
273	ldr     r1, _TEXT_BASE
274	add	lr, r0, r1
275	add	lr, lr, r9
276	/* setup parameters for board_init_r */
277	mov	r0, r5		/* gd_t */
278	mov	r1, r6		/* dest_addr */
279	/* jump to it ... */
280	mov	pc, lr
281
282_board_init_r_ofs:
283	.word board_init_r - _start
284#endif
285
286_rel_dyn_start_ofs:
287	.word __rel_dyn_start - _start
288_rel_dyn_end_ofs:
289	.word __rel_dyn_end - _start
290_dynsym_start_ofs:
291	.word __dynsym_start - _start
292
293/*
294 *************************************************************************
295 *
296 * CPU_init_critical registers
297 *
298 * setup important registers
299 * setup memory timing
300 *
301 *************************************************************************
302 */
303#ifndef CONFIG_SKIP_LOWLEVEL_INIT
304cpu_init_crit:
305	/*
306	 * flush v4 I/D caches
307	 */
308	mov	r0, #0
309	mcr	p15, 0, r0, c7, c7, 0	/* Invalidate I+D+BTB caches */
310	mcr	p15, 0, r0, c8, c7, 0	/* Invalidate Unified TLB */
311
312	/*
313	 * disable MMU stuff and caches
314	 */
315	mrc	p15, 0, r0, c1, c0, 0
316	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
317	bic	r0, r0, #0x00000087	@ clear bits 7, 2:0 (B--- -CAM)
318	orr	r0, r0, #0x00000002	@ set bit 2 (A) Align
319	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-Cache
320	mcr	p15, 0, r0, c1, c0, 0
321
322	/*
323	 * Jump to board specific initialization... The Mask ROM will have already initialized
324	 * basic memory.  Go here to bump up clock rate and handle wake up conditions.
325	 */
326	mov	ip, lr		/* persevere link reg across call */
327	bl	lowlevel_init	/* go setup pll,mux,memory */
328	mov	lr, ip		/* restore link */
329	mov	pc, lr		/* back to my caller */
330#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
331
332#ifndef CONFIG_SPL_BUILD
333/*
334 *************************************************************************
335 *
336 * Interrupt handling
337 *
338 *************************************************************************
339 */
340@
341@ IRQ stack frame.
342@
343#define S_FRAME_SIZE	72
344
345#define S_OLD_R0	68
346#define S_PSR		64
347#define S_PC		60
348#define S_LR		56
349#define S_SP		52
350
351#define S_IP		48
352#define S_FP		44
353#define S_R10		40
354#define S_R9		36
355#define S_R8		32
356#define S_R7		28
357#define S_R6		24
358#define S_R5		20
359#define S_R4		16
360#define S_R3		12
361#define S_R2		8
362#define S_R1		4
363#define S_R0		0
364
365#define MODE_SVC 0x13
366#define I_BIT	 0x80
367
368/*
369 * use bad_save_user_regs for abort/prefetch/undef/swi ...
370 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
371 */
372
373	.macro	bad_save_user_regs
374	sub	sp, sp, #S_FRAME_SIZE		@ carve out a frame on current user stack
375	stmia	sp, {r0 - r12}			@ Save user registers (now in svc mode) r0-r12
376
377	ldr	r2, IRQ_STACK_START_IN		@ set base 2 words into abort stack
378	ldmia	r2, {r2 - r3}			@ get values for "aborted" pc and cpsr (into parm regs)
379	add	r0, sp, #S_FRAME_SIZE		@ grab pointer to old stack
380
381	add	r5, sp, #S_SP
382	mov	r1, lr
383	stmia	r5, {r0 - r3}			@ save sp_SVC, lr_SVC, pc, cpsr
384	mov	r0, sp				@ save current stack into r0 (param register)
385	.endm
386
387	.macro	irq_save_user_regs
388	sub	sp, sp, #S_FRAME_SIZE
389	stmia	sp, {r0 - r12}			@ Calling r0-r12
390	add	r8, sp, #S_PC			@ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
391	stmdb	r8, {sp, lr}^			@ Calling SP, LR
392	str	lr, [r8, #0]			@ Save calling PC
393	mrs	r6, spsr
394	str	r6, [r8, #4]			@ Save CPSR
395	str	r0, [r8, #8]			@ Save OLD_R0
396	mov	r0, sp
397	.endm
398
399	.macro	irq_restore_user_regs
400	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
401	mov	r0, r0
402	ldr	lr, [sp, #S_PC]			@ Get PC
403	add	sp, sp, #S_FRAME_SIZE
404	subs	pc, lr, #4			@ return & move spsr_svc into cpsr
405	.endm
406
407	.macro get_bad_stack
408	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack (enter in banked mode)
409
410	str	lr, [r13]			@ save caller lr in position 0 of saved stack
411	mrs	lr, spsr			@ get the spsr
412	str	lr, [r13, #4]			@ save spsr in position 1 of saved stack
413
414	mov	r13, #MODE_SVC			@ prepare SVC-Mode
415	@ msr	spsr_c, r13
416	msr	spsr, r13			@ switch modes, make sure moves will execute
417	mov	lr, pc				@ capture return pc
418	movs	pc, lr				@ jump to next instruction & switch modes.
419	.endm
420
421	.macro get_bad_stack_swi
422	sub	r13, r13, #4			@ space on current stack for scratch reg.
423	str	r0, [r13]			@ save R0's value.
424	ldr	r0, IRQ_STACK_START_IN		@ get data regions start
425	str	lr, [r0]			@ save caller lr in position 0 of saved stack
426	mrs	r0, spsr			@ get the spsr
427	str	lr, [r0, #4]			@ save spsr in position 1 of saved stack
428	ldr	r0, [r13]			@ restore r0
429	add	r13, r13, #4			@ pop stack entry
430	.endm
431
432	.macro get_irq_stack			@ setup IRQ stack
433	ldr	sp, IRQ_STACK_START
434	.endm
435
436	.macro get_fiq_stack			@ setup FIQ stack
437	ldr	sp, FIQ_STACK_START
438	.endm
439#endif	/* CONFIG_SPL_BUILD */
440
441/*
442 * exception handlers
443 */
444#ifdef CONFIG_SPL_BUILD
445	.align	5
446do_hang:
447	ldr	sp, _TEXT_BASE			/* use 32 words about stack */
448	bl	hang				/* hang and never return */
449#else	/* !CONFIG_SPL_BUILD */
450	.align	5
451undefined_instruction:
452	get_bad_stack
453	bad_save_user_regs
454	bl	do_undefined_instruction
455
456	.align	5
457software_interrupt:
458	get_bad_stack_swi
459	bad_save_user_regs
460	bl	do_software_interrupt
461
462	.align	5
463prefetch_abort:
464	get_bad_stack
465	bad_save_user_regs
466	bl	do_prefetch_abort
467
468	.align	5
469data_abort:
470	get_bad_stack
471	bad_save_user_regs
472	bl	do_data_abort
473
474	.align	5
475not_used:
476	get_bad_stack
477	bad_save_user_regs
478	bl	do_not_used
479
480#ifdef CONFIG_USE_IRQ
481
482	.align	5
483irq:
484	get_irq_stack
485	irq_save_user_regs
486	bl	do_irq
487	irq_restore_user_regs
488
489	.align	5
490fiq:
491	get_fiq_stack
492	/* someone ought to write a more effiction fiq_save_user_regs */
493	irq_save_user_regs
494	bl	do_fiq
495	irq_restore_user_regs
496
497#else
498
499	.align	5
500irq:
501	get_bad_stack
502	bad_save_user_regs
503	bl	do_irq
504
505	.align	5
506fiq:
507	get_bad_stack
508	bad_save_user_regs
509	bl	do_fiq
510
511#endif
512	.align 5
513.global arm1136_cache_flush
514arm1136_cache_flush:
515#if !defined(CONFIG_SYS_ICACHE_OFF)
516		mcr	p15, 0, r1, c7, c5, 0	@ invalidate I cache
517#endif
518#if !defined(CONFIG_SYS_DCACHE_OFF)
519		mcr	p15, 0, r1, c7, c14, 0	@ invalidate D cache
520#endif
521		mov	pc, lr			@ back to caller
522#endif	/* CONFIG_SPL_BUILD */
523