xref: /openbmc/u-boot/arch/arm/cpu/arm1136/start.S (revision 150c2493)
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	moveq	r9, #0		/* no relocation. relocation offset(r9) = 0 */
194	beq	clear_bss		/* skip relocation */
195	mov	r1, r6			/* r1 <- scratch for copy_loop */
196	ldr	r3, _bss_start_ofs
197	add	r2, r0, r3		/* r2 <- source end address	    */
198
199copy_loop:
200	ldmia	r0!, {r9-r10}		/* copy from source address [r0]    */
201	stmia	r1!, {r9-r10}		/* copy to   target address [r1]    */
202	cmp	r0, r2			/* until source end address [r2]    */
203	blo	copy_loop
204
205#ifndef CONFIG_SPL_BUILD
206	/*
207	 * fix .rel.dyn relocations
208	 */
209	ldr	r0, _TEXT_BASE		/* r0 <- Text base */
210	sub	r9, r6, r0		/* r9 <- relocation offset */
211	ldr	r10, _dynsym_start_ofs	/* r10 <- sym table ofs */
212	add	r10, r10, r0		/* r10 <- sym table in FLASH */
213	ldr	r2, _rel_dyn_start_ofs	/* r2 <- rel dyn start ofs */
214	add	r2, r2, r0		/* r2 <- rel dyn start in FLASH */
215	ldr	r3, _rel_dyn_end_ofs	/* r3 <- rel dyn end ofs */
216	add	r3, r3, r0		/* r3 <- rel dyn end in FLASH */
217fixloop:
218	ldr	r0, [r2]		/* r0 <- location to fix up, IN FLASH! */
219	add	r0, r0, r9		/* r0 <- location to fix up in RAM */
220	ldr	r1, [r2, #4]
221	and	r7, r1, #0xff
222	cmp	r7, #23			/* relative fixup? */
223	beq	fixrel
224	cmp	r7, #2			/* absolute fixup? */
225	beq	fixabs
226	/* ignore unknown type of fixup */
227	b	fixnext
228fixabs:
229	/* absolute fix: set location to (offset) symbol value */
230	mov	r1, r1, LSR #4		/* r1 <- symbol index in .dynsym */
231	add	r1, r10, r1		/* r1 <- address of symbol in table */
232	ldr	r1, [r1, #4]		/* r1 <- symbol value */
233	add	r1, r1, r9		/* r1 <- relocated sym addr */
234	b	fixnext
235fixrel:
236	/* relative fix: increase location by offset */
237	ldr	r1, [r0]
238	add	r1, r1, r9
239fixnext:
240	str	r1, [r0]
241	add	r2, r2, #8		/* each rel.dyn entry is 8 bytes */
242	cmp	r2, r3
243	blo	fixloop
244#endif
245
246clear_bss:
247#ifndef CONFIG_SPL_BUILD
248	ldr	r0, _bss_start_ofs
249	ldr	r1, _bss_end_ofs
250	mov	r4, r6			/* reloc addr */
251	add	r0, r0, r4
252	add	r1, r1, r4
253	mov	r2, #0x00000000		/* clear			    */
254
255clbss_l:cmp	r0, r1			/* clear loop... */
256	bhs	clbss_e			/* if reached end of bss, exit */
257	str	r2, [r0]
258	add	r0, r0, #4
259	b	clbss_l
260clbss_e:
261#endif	/* #ifndef CONFIG_SPL_BUILD */
262
263/*
264 * We are done. Do not return, instead branch to second part of board
265 * initialization, now running from RAM.
266 */
267#ifdef CONFIG_NAND_SPL
268	ldr     r0, _nand_boot_ofs
269	mov	pc, r0
270
271_nand_boot_ofs:
272	.word nand_boot
273#else
274jump_2_ram:
275	ldr	r0, _board_init_r_ofs
276	ldr     r1, _TEXT_BASE
277	add	lr, r0, r1
278	add	lr, lr, r9
279	/* setup parameters for board_init_r */
280	mov	r0, r5		/* gd_t */
281	mov	r1, r6		/* dest_addr */
282	/* jump to it ... */
283	mov	pc, lr
284
285_board_init_r_ofs:
286	.word board_init_r - _start
287#endif
288
289_rel_dyn_start_ofs:
290	.word __rel_dyn_start - _start
291_rel_dyn_end_ofs:
292	.word __rel_dyn_end - _start
293_dynsym_start_ofs:
294	.word __dynsym_start - _start
295
296/*
297 *************************************************************************
298 *
299 * CPU_init_critical registers
300 *
301 * setup important registers
302 * setup memory timing
303 *
304 *************************************************************************
305 */
306#ifndef CONFIG_SKIP_LOWLEVEL_INIT
307cpu_init_crit:
308	/*
309	 * flush v4 I/D caches
310	 */
311	mov	r0, #0
312	mcr	p15, 0, r0, c7, c7, 0	/* Invalidate I+D+BTB caches */
313	mcr	p15, 0, r0, c8, c7, 0	/* Invalidate Unified TLB */
314
315	/*
316	 * disable MMU stuff and caches
317	 */
318	mrc	p15, 0, r0, c1, c0, 0
319	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
320	bic	r0, r0, #0x00000087	@ clear bits 7, 2:0 (B--- -CAM)
321	orr	r0, r0, #0x00000002	@ set bit 2 (A) Align
322	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-Cache
323	mcr	p15, 0, r0, c1, c0, 0
324
325	/*
326	 * Jump to board specific initialization... The Mask ROM will have already initialized
327	 * basic memory.  Go here to bump up clock rate and handle wake up conditions.
328	 */
329	mov	ip, lr		/* persevere link reg across call */
330	bl	lowlevel_init	/* go setup pll,mux,memory */
331	mov	lr, ip		/* restore link */
332	mov	pc, lr		/* back to my caller */
333#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
334
335#ifndef CONFIG_SPL_BUILD
336/*
337 *************************************************************************
338 *
339 * Interrupt handling
340 *
341 *************************************************************************
342 */
343@
344@ IRQ stack frame.
345@
346#define S_FRAME_SIZE	72
347
348#define S_OLD_R0	68
349#define S_PSR		64
350#define S_PC		60
351#define S_LR		56
352#define S_SP		52
353
354#define S_IP		48
355#define S_FP		44
356#define S_R10		40
357#define S_R9		36
358#define S_R8		32
359#define S_R7		28
360#define S_R6		24
361#define S_R5		20
362#define S_R4		16
363#define S_R3		12
364#define S_R2		8
365#define S_R1		4
366#define S_R0		0
367
368#define MODE_SVC 0x13
369#define I_BIT	 0x80
370
371/*
372 * use bad_save_user_regs for abort/prefetch/undef/swi ...
373 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
374 */
375
376	.macro	bad_save_user_regs
377	sub	sp, sp, #S_FRAME_SIZE		@ carve out a frame on current user stack
378	stmia	sp, {r0 - r12}			@ Save user registers (now in svc mode) r0-r12
379
380	ldr	r2, IRQ_STACK_START_IN		@ set base 2 words into abort stack
381	ldmia	r2, {r2 - r3}			@ get values for "aborted" pc and cpsr (into parm regs)
382	add	r0, sp, #S_FRAME_SIZE		@ grab pointer to old stack
383
384	add	r5, sp, #S_SP
385	mov	r1, lr
386	stmia	r5, {r0 - r3}			@ save sp_SVC, lr_SVC, pc, cpsr
387	mov	r0, sp				@ save current stack into r0 (param register)
388	.endm
389
390	.macro	irq_save_user_regs
391	sub	sp, sp, #S_FRAME_SIZE
392	stmia	sp, {r0 - r12}			@ Calling r0-r12
393	add	r8, sp, #S_PC			@ !!!! R8 NEEDS to be saved !!!! a reserved stack spot would be good.
394	stmdb	r8, {sp, lr}^			@ Calling SP, LR
395	str	lr, [r8, #0]			@ Save calling PC
396	mrs	r6, spsr
397	str	r6, [r8, #4]			@ Save CPSR
398	str	r0, [r8, #8]			@ Save OLD_R0
399	mov	r0, sp
400	.endm
401
402	.macro	irq_restore_user_regs
403	ldmia	sp, {r0 - lr}^			@ Calling r0 - lr
404	mov	r0, r0
405	ldr	lr, [sp, #S_PC]			@ Get PC
406	add	sp, sp, #S_FRAME_SIZE
407	subs	pc, lr, #4			@ return & move spsr_svc into cpsr
408	.endm
409
410	.macro get_bad_stack
411	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack (enter in banked mode)
412
413	str	lr, [r13]			@ save caller lr in position 0 of saved stack
414	mrs	lr, spsr			@ get the spsr
415	str	lr, [r13, #4]			@ save spsr in position 1 of saved stack
416
417	mov	r13, #MODE_SVC			@ prepare SVC-Mode
418	@ msr	spsr_c, r13
419	msr	spsr, r13			@ switch modes, make sure moves will execute
420	mov	lr, pc				@ capture return pc
421	movs	pc, lr				@ jump to next instruction & switch modes.
422	.endm
423
424	.macro get_bad_stack_swi
425	sub	r13, r13, #4			@ space on current stack for scratch reg.
426	str	r0, [r13]			@ save R0's value.
427	ldr	r0, IRQ_STACK_START_IN		@ get data regions start
428	str	lr, [r0]			@ save caller lr in position 0 of saved stack
429	mrs	r0, spsr			@ get the spsr
430	str	lr, [r0, #4]			@ save spsr in position 1 of saved stack
431	ldr	r0, [r13]			@ restore r0
432	add	r13, r13, #4			@ pop stack entry
433	.endm
434
435	.macro get_irq_stack			@ setup IRQ stack
436	ldr	sp, IRQ_STACK_START
437	.endm
438
439	.macro get_fiq_stack			@ setup FIQ stack
440	ldr	sp, FIQ_STACK_START
441	.endm
442#endif	/* CONFIG_SPL_BUILD */
443
444/*
445 * exception handlers
446 */
447#ifdef CONFIG_SPL_BUILD
448	.align	5
449do_hang:
450	ldr	sp, _TEXT_BASE			/* use 32 words about stack */
451	bl	hang				/* hang and never return */
452#else	/* !CONFIG_SPL_BUILD */
453	.align	5
454undefined_instruction:
455	get_bad_stack
456	bad_save_user_regs
457	bl	do_undefined_instruction
458
459	.align	5
460software_interrupt:
461	get_bad_stack_swi
462	bad_save_user_regs
463	bl	do_software_interrupt
464
465	.align	5
466prefetch_abort:
467	get_bad_stack
468	bad_save_user_regs
469	bl	do_prefetch_abort
470
471	.align	5
472data_abort:
473	get_bad_stack
474	bad_save_user_regs
475	bl	do_data_abort
476
477	.align	5
478not_used:
479	get_bad_stack
480	bad_save_user_regs
481	bl	do_not_used
482
483#ifdef CONFIG_USE_IRQ
484
485	.align	5
486irq:
487	get_irq_stack
488	irq_save_user_regs
489	bl	do_irq
490	irq_restore_user_regs
491
492	.align	5
493fiq:
494	get_fiq_stack
495	/* someone ought to write a more effiction fiq_save_user_regs */
496	irq_save_user_regs
497	bl	do_fiq
498	irq_restore_user_regs
499
500#else
501
502	.align	5
503irq:
504	get_bad_stack
505	bad_save_user_regs
506	bl	do_irq
507
508	.align	5
509fiq:
510	get_bad_stack
511	bad_save_user_regs
512	bl	do_fiq
513
514#endif
515	.align 5
516.global arm1136_cache_flush
517arm1136_cache_flush:
518#if !defined(CONFIG_SYS_ICACHE_OFF)
519		mcr	p15, 0, r1, c7, c5, 0	@ invalidate I cache
520#endif
521#if !defined(CONFIG_SYS_DCACHE_OFF)
522		mcr	p15, 0, r1, c7, c14, 0	@ invalidate D cache
523#endif
524		mov	pc, lr			@ back to caller
525#endif	/* CONFIG_SPL_BUILD */
526