xref: /openbmc/u-boot/arch/arm/cpu/arm1136/start.S (revision 6d8962e814c15807dd6ac5757904be2a02d187b8)
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	ldr	r0,=0x00000000
164
165#ifdef CONFIG_NAND_SPL
166	bl	nand_boot
167#else
168#ifdef CONFIG_ONENAND_IPL
169	bl	start_oneboot
170#else
171	bl	board_init_f
172#endif /* CONFIG_ONENAND_IPL */
173#endif /* CONFIG_NAND_SPL */
174
175/*------------------------------------------------------------------------------*/
176
177/*
178 * void relocate_code (addr_sp, gd, addr_moni)
179 *
180 * This "function" does not return, instead it continues in RAM
181 * after relocating the monitor code.
182 *
183 */
184	.globl	relocate_code
185relocate_code:
186	mov	r4, r0	/* save addr_sp */
187	mov	r5, r1	/* save addr of gd */
188	mov	r6, r2	/* save addr of destination */
189	mov	r7, r2	/* save addr of destination */
190
191	/* Set up the stack						    */
192stack_setup:
193	mov	sp, r4
194
195	adr	r0, _start
196	ldr	r2, _TEXT_BASE
197	ldr	r3, _bss_start_ofs
198	add	r2, r0, r3		/* r2 <- source end address	    */
199	cmp	r0, r6
200	beq	clear_bss
201
202copy_loop:
203	ldmia	r0!, {r9-r10}		/* copy from source address [r0]    */
204	stmia	r6!, {r9-r10}		/* copy to   target address [r1]    */
205	cmp	r0, r2			/* until source end address [r2]    */
206	blo	copy_loop
207
208#ifndef CONFIG_PRELOADER
209	/*
210	 * fix .rel.dyn relocations
211	 */
212	ldr	r0, _TEXT_BASE		/* r0 <- Text base */
213	sub	r9, r7, r0		/* r9 <- relocation offset */
214	ldr	r10, _dynsym_start_ofs	/* r10 <- sym table ofs */
215	add	r10, r10, r0		/* r10 <- sym table in FLASH */
216	ldr	r2, _rel_dyn_start_ofs	/* r2 <- rel dyn start ofs */
217	add	r2, r2, r0		/* r2 <- rel dyn start in FLASH */
218	ldr	r3, _rel_dyn_end_ofs	/* r3 <- rel dyn end ofs */
219	add	r3, r3, r0		/* r3 <- rel dyn end in FLASH */
220fixloop:
221	ldr	r0, [r2]		/* r0 <- location to fix up, IN FLASH! */
222	add	r0, r0, r9		/* r0 <- location to fix up in RAM */
223	ldr	r1, [r2, #4]
224	and	r8, r1, #0xff
225	cmp	r8, #23			/* relative fixup? */
226	beq	fixrel
227	cmp	r8, #2			/* absolute fixup? */
228	beq	fixabs
229	/* ignore unknown type of fixup */
230	b	fixnext
231fixabs:
232	/* absolute fix: set location to (offset) symbol value */
233	mov	r1, r1, LSR #4		/* r1 <- symbol index in .dynsym */
234	add	r1, r10, r1		/* r1 <- address of symbol in table */
235	ldr	r1, [r1, #4]		/* r1 <- symbol value */
236	add	r1, r9			/* r1 <- relocated sym addr */
237	b	fixnext
238fixrel:
239	/* relative fix: increase location by offset */
240	ldr	r1, [r0]
241	add	r1, r1, r9
242fixnext:
243	str	r1, [r0]
244	add	r2, r2, #8		/* each rel.dyn entry is 8 bytes */
245	cmp	r2, r3
246	blo	fixloop
247#endif
248
249clear_bss:
250#ifndef CONFIG_PRELOADER
251	ldr	r0, _bss_start_ofs
252	ldr	r1, _bss_end_ofs
253	ldr	r3, _TEXT_BASE		/* Text base */
254	mov	r4, r7			/* reloc addr */
255	add	r0, r0, r4
256	add	r1, r1, r4
257	mov	r2, #0x00000000		/* clear			    */
258
259clbss_l:str	r2, [r0]		/* clear loop...		    */
260	add	r0, r0, #4
261	cmp	r0, r1
262	bne	clbss_l
263#endif	/* #ifndef CONFIG_PRELOADER */
264
265/*
266 * We are done. Do not return, instead branch to second part of board
267 * initialization, now running from RAM.
268 */
269#ifdef CONFIG_NAND_SPL
270	ldr     r0, _nand_boot_ofs
271	adr	r1, _start
272	add	pc, r0, r1
273_nand_boot_ofs
274	: .word nand_boot - _start
275#else
276jump_2_ram:
277	ldr	r0, _board_init_r_ofs
278	adr	r1, _start
279	add	lr, r0, r1
280	add	lr, lr, r9
281	/* setup parameters for board_init_r */
282	mov	r0, r5		/* gd_t */
283	mov	r1, r7		/* dest_addr */
284	/* jump to it ... */
285	mov	pc, lr
286
287_board_init_r_ofs:
288	.word board_init_r - _start
289#endif
290
291_rel_dyn_start_ofs:
292	.word __rel_dyn_start - _start
293_rel_dyn_end_ofs:
294	.word __rel_dyn_end - _start
295_dynsym_start_ofs:
296	.word __dynsym_start - _start
297
298/*
299 *************************************************************************
300 *
301 * CPU_init_critical registers
302 *
303 * setup important registers
304 * setup memory timing
305 *
306 *************************************************************************
307 */
308#ifndef CONFIG_SKIP_LOWLEVEL_INIT
309cpu_init_crit:
310	/*
311	 * flush v4 I/D caches
312	 */
313	mov	r0, #0
314	mcr	p15, 0, r0, c7, c7, 0	/* Invalidate I+D+BTB caches */
315	mcr	p15, 0, r0, c8, c7, 0	/* Invalidate Unified TLB */
316
317	/*
318	 * disable MMU stuff and caches
319	 */
320	mrc	p15, 0, r0, c1, c0, 0
321	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
322	bic	r0, r0, #0x00000087	@ clear bits 7, 2:0 (B--- -CAM)
323	orr	r0, r0, #0x00000002	@ set bit 2 (A) Align
324	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-Cache
325	mcr	p15, 0, r0, c1, c0, 0
326
327	/*
328	 * Jump to board specific initialization... The Mask ROM will have already initialized
329	 * basic memory.  Go here to bump up clock rate and handle wake up conditions.
330	 */
331	mov	ip, lr		/* persevere link reg across call */
332	bl	lowlevel_init	/* go setup pll,mux,memory */
333	mov	lr, ip		/* restore link */
334	mov	pc, lr		/* back to my caller */
335#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
336
337#ifndef CONFIG_PRELOADER
338/*
339 *************************************************************************
340 *
341 * Interrupt handling
342 *
343 *************************************************************************
344 */
345@
346@ IRQ stack frame.
347@
348#define S_FRAME_SIZE	72
349
350#define S_OLD_R0	68
351#define S_PSR		64
352#define S_PC		60
353#define S_LR		56
354#define S_SP		52
355
356#define S_IP		48
357#define S_FP		44
358#define S_R10		40
359#define S_R9		36
360#define S_R8		32
361#define S_R7		28
362#define S_R6		24
363#define S_R5		20
364#define S_R4		16
365#define S_R3		12
366#define S_R2		8
367#define S_R1		4
368#define S_R0		0
369
370#define MODE_SVC 0x13
371#define I_BIT	 0x80
372
373/*
374 * use bad_save_user_regs for abort/prefetch/undef/swi ...
375 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
376 */
377
378	.macro	bad_save_user_regs
379	sub	sp, sp, #S_FRAME_SIZE		@ carve out a frame on current user stack
380	stmia	sp, {r0 - r12}			@ Save user registers (now in svc mode) r0-r12
381
382	ldr	r2, IRQ_STACK_START_IN		@ set base 2 words into abort stack
383	ldmia	r2, {r2 - r3}			@ get values for "aborted" pc and cpsr (into parm regs)
384	add	r0, sp, #S_FRAME_SIZE		@ grab pointer to old stack
385
386	add	r5, sp, #S_SP
387	mov	r1, lr
388	stmia	r5, {r0 - r3}			@ save sp_SVC, lr_SVC, pc, cpsr
389	mov	r0, sp				@ save current stack into r0 (param register)
390	.endm
391
392	.macro	irq_save_user_regs
393	sub	sp, sp, #S_FRAME_SIZE
394	stmia	sp, {r0 - r12}			@ Calling r0-r12
395	add	r8, sp, #S_PC			@ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
396	stmdb	r8, {sp, lr}^			@ Calling SP, LR
397	str	lr, [r8, #0]			@ Save calling PC
398	mrs	r6, spsr
399	str	r6, [r8, #4]			@ Save CPSR
400	str	r0, [r8, #8]			@ Save OLD_R0
401	mov	r0, sp
402	.endm
403
404	.macro	irq_restore_user_regs
405	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
406	mov	r0, r0
407	ldr	lr, [sp, #S_PC]			@ Get PC
408	add	sp, sp, #S_FRAME_SIZE
409	subs	pc, lr, #4			@ return & move spsr_svc into cpsr
410	.endm
411
412	.macro get_bad_stack
413	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack (enter in banked mode)
414
415	str	lr, [r13]			@ save caller lr in position 0 of saved stack
416	mrs	lr, spsr			@ get the spsr
417	str	lr, [r13, #4]			@ save spsr in position 1 of saved stack
418
419	mov	r13, #MODE_SVC			@ prepare SVC-Mode
420	@ msr	spsr_c, r13
421	msr	spsr, r13			@ switch modes, make sure moves will execute
422	mov	lr, pc				@ capture return pc
423	movs	pc, lr				@ jump to next instruction & switch modes.
424	.endm
425
426	.macro get_bad_stack_swi
427	sub	r13, r13, #4			@ space on current stack for scratch reg.
428	str	r0, [r13]			@ save R0's value.
429	ldr	r0, IRQ_STACK_START_IN		@ get data regions start
430	str	lr, [r0]			@ save caller lr in position 0 of saved stack
431	mrs	r0, spsr			@ get the spsr
432	str	lr, [r0, #4]			@ save spsr in position 1 of saved stack
433	ldr	r0, [r13]			@ restore r0
434	add	r13, r13, #4			@ pop stack entry
435	.endm
436
437	.macro get_irq_stack			@ setup IRQ stack
438	ldr	sp, IRQ_STACK_START
439	.endm
440
441	.macro get_fiq_stack			@ setup FIQ stack
442	ldr	sp, FIQ_STACK_START
443	.endm
444#endif	/* CONFIG_PRELOADER */
445
446/*
447 * exception handlers
448 */
449#ifdef CONFIG_PRELOADER
450	.align	5
451do_hang:
452	ldr	sp, _TEXT_BASE			/* use 32 words about stack */
453	bl	hang				/* hang and never return */
454#else	/* !CONFIG_PRELOADER */
455	.align	5
456undefined_instruction:
457	get_bad_stack
458	bad_save_user_regs
459	bl	do_undefined_instruction
460
461	.align	5
462software_interrupt:
463	get_bad_stack_swi
464	bad_save_user_regs
465	bl	do_software_interrupt
466
467	.align	5
468prefetch_abort:
469	get_bad_stack
470	bad_save_user_regs
471	bl	do_prefetch_abort
472
473	.align	5
474data_abort:
475	get_bad_stack
476	bad_save_user_regs
477	bl	do_data_abort
478
479	.align	5
480not_used:
481	get_bad_stack
482	bad_save_user_regs
483	bl	do_not_used
484
485#ifdef CONFIG_USE_IRQ
486
487	.align	5
488irq:
489	get_irq_stack
490	irq_save_user_regs
491	bl	do_irq
492	irq_restore_user_regs
493
494	.align	5
495fiq:
496	get_fiq_stack
497	/* someone ought to write a more effiction fiq_save_user_regs */
498	irq_save_user_regs
499	bl	do_fiq
500	irq_restore_user_regs
501
502#else
503
504	.align	5
505irq:
506	get_bad_stack
507	bad_save_user_regs
508	bl	do_irq
509
510	.align	5
511fiq:
512	get_bad_stack
513	bad_save_user_regs
514	bl	do_fiq
515
516#endif
517	.align 5
518.global arm1136_cache_flush
519arm1136_cache_flush:
520#if !defined(CONFIG_SYS_NO_ICACHE)
521		mcr	p15, 0, r1, c7, c5, 0	@ invalidate I cache
522#endif
523#if !defined(CONFIG_SYS_NO_DCACHE)
524		mcr	p15, 0, r1, c7, c14, 0	@ invalidate D cache
525#endif
526		mov	pc, lr			@ back to caller
527#endif	/* CONFIG_PRELOADER */
528