xref: /openbmc/u-boot/arch/arm/cpu/arm1176/start.S (revision 1155d555)
1/*
2 *  armboot - Startup Code for ARM1176 CPU-core
3 *
4 * Copyright (c) 2007	Samsung Electronics
5 *
6 * Copyright (C) 2008
7 * Guennadi Liakhovetki, DENX Software Engineering, <lg@denx.de>
8 *
9 * See file CREDITS for list of people who contributed to this
10 * project.
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License as
14 * published by the Free Software Foundation; either version 2 of
15 * the License, or (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
25 * MA 02111-1307 USA
26 *
27 * 2007-09-21 - Restructured codes by jsgood (jsgood.yang@samsung.com)
28 * 2007-09-21 - Added MoviNAND and OneNAND boot codes by
29 * jsgood (jsgood.yang@samsung.com)
30 * Base codes by scsuh (sc.suh)
31 */
32
33#include <asm-offsets.h>
34#include <config.h>
35#include <version.h>
36
37#ifndef CONFIG_SYS_PHY_UBOOT_BASE
38#define CONFIG_SYS_PHY_UBOOT_BASE	CONFIG_SYS_UBOOT_BASE
39#endif
40
41/*
42 *************************************************************************
43 *
44 * Jump vector table as in table 3.1 in [1]
45 *
46 *************************************************************************
47 */
48
49.globl _start
50_start: b	reset
51#ifndef CONFIG_SPL_BUILD
52	ldr	pc, _undefined_instruction
53	ldr	pc, _software_interrupt
54	ldr	pc, _prefetch_abort
55	ldr	pc, _data_abort
56	ldr	pc, _not_used
57	ldr	pc, _irq
58	ldr	pc, _fiq
59
60_undefined_instruction:
61	.word undefined_instruction
62_software_interrupt:
63	.word software_interrupt
64_prefetch_abort:
65	.word prefetch_abort
66_data_abort:
67	.word data_abort
68_not_used:
69	.word not_used
70_irq:
71	.word irq
72_fiq:
73	.word fiq
74_pad:
75	.word 0x12345678 /* now 16*4=64 */
76#else
77	. = _start + 64
78#endif
79
80.global _end_vect
81_end_vect:
82	.balignl 16,0xdeadbeef
83/*
84 *************************************************************************
85 *
86 * Startup Code (reset vector)
87 *
88 * do important init only if we don't start from memory!
89 * setup Memory and board specific bits prior to relocation.
90 * relocate armboot to ram
91 * setup stack
92 *
93 *************************************************************************
94 */
95
96.globl _TEXT_BASE
97_TEXT_BASE:
98#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_TEXT_BASE)
99	.word	CONFIG_SPL_TEXT_BASE
100#else
101	.word	CONFIG_SYS_TEXT_BASE
102#endif
103
104/*
105 * These are defined in the board-specific linker script.
106 * Subtracting _start from them lets the linker put their
107 * relative position in the executable instead of leaving
108 * them null.
109 */
110
111.globl _bss_start_ofs
112_bss_start_ofs:
113	.word __bss_start - _start
114
115.globl _image_copy_end_ofs
116_image_copy_end_ofs:
117	.word __image_copy_end - _start
118
119.globl _bss_end_ofs
120_bss_end_ofs:
121	.word __bss_end - _start
122
123.globl _end_ofs
124_end_ofs:
125	.word _end - _start
126
127/* IRQ stack memory (calculated at run-time) + 8 bytes */
128.globl IRQ_STACK_START_IN
129IRQ_STACK_START_IN:
130	.word	0x0badc0de
131
132/*
133 * the actual reset code
134 */
135
136reset:
137	/*
138	 * set the cpu to SVC32 mode
139	 */
140	mrs	r0, cpsr
141	bic	r0, r0, #0x3f
142	orr	r0, r0, #0xd3
143	msr	cpsr, r0
144
145/*
146 *************************************************************************
147 *
148 * CPU_init_critical registers
149 *
150 * setup important registers
151 * setup memory timing
152 *
153 *************************************************************************
154 */
155	/*
156	 * we do sys-critical inits only at reboot,
157	 * not when booting from ram!
158	 */
159cpu_init_crit:
160	/*
161	 * When booting from NAND - it has definitely been a reset, so, no need
162	 * to flush caches and disable the MMU
163	 */
164#ifndef CONFIG_SPL_BUILD
165	/*
166	 * flush v4 I/D caches
167	 */
168	mov	r0, #0
169	mcr	p15, 0, r0, c7, c7, 0	/* flush v3/v4 cache */
170	mcr	p15, 0, r0, c8, c7, 0	/* flush v4 TLB */
171
172	/*
173	 * disable MMU stuff and caches
174	 */
175	mrc	p15, 0, r0, c1, c0, 0
176	bic	r0, r0, #0x00002300	@ clear bits 13, 9:8 (--V- --RS)
177	bic	r0, r0, #0x00000087	@ clear bits 7, 2:0 (B--- -CAM)
178	orr	r0, r0, #0x00000002	@ set bit 2 (A) Align
179	orr	r0, r0, #0x00001000	@ set bit 12 (I) I-Cache
180
181	/* Prepare to disable the MMU */
182	adr	r2, mmu_disable_phys
183	sub	r2, r2, #(CONFIG_SYS_PHY_UBOOT_BASE - CONFIG_SYS_TEXT_BASE)
184	b	mmu_disable
185
186	.align 5
187	/* Run in a single cache-line */
188mmu_disable:
189	mcr	p15, 0, r0, c1, c0, 0
190	nop
191	nop
192	mov	pc, r2
193mmu_disable_phys:
194
195#ifdef CONFIG_DISABLE_TCM
196	/*
197	 * Disable the TCMs
198	 */
199	mrc	p15, 0, r0, c0, c0, 2	/* Return TCM details */
200	cmp	r0, #0
201	beq	skip_tcmdisable
202	mov	r1, #0
203	mov	r2, #1
204	tst	r0, r2
205	mcrne	p15, 0, r1, c9, c1, 1	/* Disable Instruction TCM if present*/
206	tst	r0, r2, LSL #16
207	mcrne	p15, 0, r1, c9, c1, 0	/* Disable Data TCM if present*/
208skip_tcmdisable:
209#endif
210#endif
211
212#ifdef CONFIG_PERIPORT_REMAP
213	/* Peri port setup */
214	ldr	r0, =CONFIG_PERIPORT_BASE
215	orr	r0, r0, #CONFIG_PERIPORT_SIZE
216	mcr	p15,0,r0,c15,c2,4
217#endif
218
219	/*
220	 * Go setup Memory and board specific bits prior to relocation.
221	 */
222	bl	lowlevel_init		/* go setup pll,mux,memory */
223
224	bl	_main
225
226/*------------------------------------------------------------------------------*/
227
228/*
229 * void relocate_code(addr_moni)
230 *
231 * This function relocates the monitor code.
232 */
233	.globl	relocate_code
234relocate_code:
235	mov	r6, r0	/* save addr of destination */
236
237	adr	r0, _start
238	subs	r9, r6, r0		/* r9 <- relocation offset */
239	beq	relocate_done		/* skip relocation */
240	mov	r1, r6			/* r1 <- scratch for copy_loop */
241	ldr	r3, _image_copy_end_ofs
242	add	r2, r0, r3		/* r2 <- source end address	    */
243
244copy_loop:
245	ldmia	r0!, {r10-r11}		/* copy from source address [r0]    */
246	stmia	r1!, {r10-r11}		/* copy to   target address [r1]    */
247	cmp	r0, r2			/* until source end address [r2]    */
248	blo	copy_loop
249
250#ifndef CONFIG_SPL_BUILD
251	/*
252	 * fix .rel.dyn relocations
253	 */
254	ldr	r0, _TEXT_BASE		/* r0 <- Text base */
255	ldr	r10, _dynsym_start_ofs	/* r10 <- sym table ofs */
256	add	r10, r10, r0		/* r10 <- sym table in FLASH */
257	ldr	r2, _rel_dyn_start_ofs	/* r2 <- rel dyn start ofs */
258	add	r2, r2, r0		/* r2 <- rel dyn start in FLASH */
259	ldr	r3, _rel_dyn_end_ofs	/* r3 <- rel dyn end ofs */
260	add	r3, r3, r0		/* r3 <- rel dyn end in FLASH */
261fixloop:
262	ldr	r0, [r2]		/* r0 <- location to fix up, IN FLASH! */
263	add	r0, r0, r9		/* r0 <- location to fix up in RAM */
264	ldr	r1, [r2, #4]
265	and	r7, r1, #0xff
266	cmp	r7, #23			/* relative fixup? */
267	beq	fixrel
268	cmp	r7, #2			/* absolute fixup? */
269	beq	fixabs
270	/* ignore unknown type of fixup */
271	b	fixnext
272fixabs:
273	/* absolute fix: set location to (offset) symbol value */
274	mov	r1, r1, LSR #4		/* r1 <- symbol index in .dynsym */
275	add	r1, r10, r1		/* r1 <- address of symbol in table */
276	ldr	r1, [r1, #4]		/* r1 <- symbol value */
277	add	r1, r1, r9		/* r1 <- relocated sym addr */
278	b	fixnext
279fixrel:
280	/* relative fix: increase location by offset */
281	ldr	r1, [r0]
282	add	r1, r1, r9
283fixnext:
284	str	r1, [r0]
285	add	r2, r2, #8		/* each rel.dyn entry is 8 bytes */
286	cmp	r2, r3
287	blo	fixloop
288#endif
289
290relocate_done:
291
292	bx	lr
293
294_rel_dyn_start_ofs:
295	.word __rel_dyn_start - _start
296_rel_dyn_end_ofs:
297	.word __rel_dyn_end - _start
298_dynsym_start_ofs:
299	.word __dynsym_start - _start
300
301	.globl	c_runtime_cpu_setup
302c_runtime_cpu_setup:
303
304	mov	pc, lr
305
306#ifndef CONFIG_SPL_BUILD
307/*
308 *************************************************************************
309 *
310 * Interrupt handling
311 *
312 *************************************************************************
313 */
314@
315@ IRQ stack frame.
316@
317#define S_FRAME_SIZE	72
318
319#define S_OLD_R0	68
320#define S_PSR		64
321#define S_PC		60
322#define S_LR		56
323#define S_SP		52
324
325#define S_IP		48
326#define S_FP		44
327#define S_R10		40
328#define S_R9		36
329#define S_R8		32
330#define S_R7		28
331#define S_R6		24
332#define S_R5		20
333#define S_R4		16
334#define S_R3		12
335#define S_R2		8
336#define S_R1		4
337#define S_R0		0
338
339#define MODE_SVC 0x13
340#define I_BIT	 0x80
341
342/*
343 * use bad_save_user_regs for abort/prefetch/undef/swi ...
344 */
345
346	.macro	bad_save_user_regs
347	/* carve out a frame on current user stack */
348	sub	sp, sp, #S_FRAME_SIZE
349	/* Save user registers (now in svc mode) r0-r12 */
350	stmia	sp, {r0 - r12}
351
352	ldr	r2, IRQ_STACK_START_IN
353	/* get values for "aborted" pc and cpsr (into parm regs) */
354	ldmia	r2, {r2 - r3}
355	/* grab pointer to old stack */
356	add	r0, sp, #S_FRAME_SIZE
357
358	add	r5, sp, #S_SP
359	mov	r1, lr
360	/* save sp_SVC, lr_SVC, pc, cpsr */
361	stmia	r5, {r0 - r3}
362	/* save current stack into r0 (param register) */
363	mov	r0, sp
364	.endm
365
366	.macro get_bad_stack
367	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
368
369	/* save caller lr in position 0 of saved stack */
370	str	lr, [r13]
371	/* get the spsr */
372	mrs	lr, spsr
373	/* save spsr in position 1 of saved stack */
374	str	lr, [r13, #4]
375
376	/* prepare SVC-Mode */
377	mov	r13, #MODE_SVC
378	@ msr	spsr_c, r13
379	/* switch modes, make sure moves will execute */
380	msr	spsr, r13
381	/* capture return pc */
382	mov	lr, pc
383	/* jump to next instruction & switch modes. */
384	movs	pc, lr
385	.endm
386
387	.macro get_bad_stack_swi
388	/* space on current stack for scratch reg. */
389	sub	r13, r13, #4
390	/* save R0's value. */
391	str	r0, [r13]
392	ldr	r13, IRQ_STACK_START_IN		@ setup our mode stack
393	/* save caller lr in position 0 of saved stack */
394	str	lr, [r0]
395	/* get the spsr */
396	mrs	lr, spsr
397	/* save spsr in position 1 of saved stack */
398	str	lr, [r0, #4]
399	/* restore lr */
400	ldr	lr, [r0]
401	/* restore r0 */
402	ldr	r0, [r13]
403	/* pop stack entry */
404	add	r13, r13, #4
405	.endm
406
407/*
408 * exception handlers
409 */
410	.align	5
411undefined_instruction:
412	get_bad_stack
413	bad_save_user_regs
414	bl	do_undefined_instruction
415
416	.align	5
417software_interrupt:
418	get_bad_stack_swi
419	bad_save_user_regs
420	bl	do_software_interrupt
421
422	.align	5
423prefetch_abort:
424	get_bad_stack
425	bad_save_user_regs
426	bl	do_prefetch_abort
427
428	.align	5
429data_abort:
430	get_bad_stack
431	bad_save_user_regs
432	bl	do_data_abort
433
434	.align	5
435not_used:
436	get_bad_stack
437	bad_save_user_regs
438	bl	do_not_used
439
440	.align	5
441irq:
442	get_bad_stack
443	bad_save_user_regs
444	bl	do_irq
445
446	.align	5
447fiq:
448	get_bad_stack
449	bad_save_user_regs
450	bl	do_fiq
451#endif /* CONFIG_SPL_BUILD */
452