summaryrefslogtreecommitdiff
path: root/arch/arm/cpu/s3c44b0/start.S
blob: 78183fc19bc40874a341e000277868164d5447f2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
/*
 * Startup Code for S3C44B0 CPU-core
 *
 * (C) Copyright 2004
 * DAVE Srl
 *
 * http://www.dave-tech.it
 * http://www.wawnet.biz
 * mailto:info@wawnet.biz
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <asm-offsets.h>
#include <config.h>
#include <version.h>

/*
 * Jump vector table
 */


.globl _start
_start:	b       reset
	add	pc, pc, #0x0c000000
	add	pc, pc, #0x0c000000
	add	pc, pc, #0x0c000000
	add	pc, pc, #0x0c000000
	add	pc, pc, #0x0c000000
	add	pc, pc, #0x0c000000
	add	pc, pc, #0x0c000000

	.balignl 16,0xdeadbeef


/*
 *************************************************************************
 *
 * Startup Code (reset vector)
 *
 * do important init only if we don't start from memory!
 * relocate u-boot to ram
 * setup stack
 * jump to second stage
 *
 *************************************************************************
 */

.globl _TEXT_BASE
_TEXT_BASE:
#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_TEXT_BASE)
	.word	CONFIG_SPL_TEXT_BASE
#else
	.word	CONFIG_SYS_TEXT_BASE
#endif

/*
 * These are defined in the board-specific linker script.
 * Subtracting _start from them lets the linker put their
 * relative position in the executable instead of leaving
 * them null.
 */
.globl _bss_start_ofs
_bss_start_ofs:
	.word __bss_start - _start

.globl _bss_end_ofs
_bss_end_ofs:
	.word __bss_end - _start

.globl _end_ofs
_end_ofs:
	.word _end - _start

#ifdef CONFIG_USE_IRQ
/* IRQ stack memory (calculated at run-time) */
.globl IRQ_STACK_START
IRQ_STACK_START:
	.word	0x0badc0de

/* IRQ stack memory (calculated at run-time) */
.globl FIQ_STACK_START
FIQ_STACK_START:
	.word 0x0badc0de
#endif

/* IRQ stack memory (calculated at run-time) + 8 bytes */
.globl IRQ_STACK_START_IN
IRQ_STACK_START_IN:
	.word	0x0badc0de

/*
 * the actual reset code
 */

reset:
	/*
	 * set the cpu to SVC32 mode
	 */
	mrs	r0,cpsr
	bic	r0,r0,#0x1f
	orr	r0,r0,#0xd3
	msr	cpsr,r0

	/*
	 * we do sys-critical inits only at reboot,
	 * not when booting from ram!
	 */
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
	bl	cpu_init_crit
	/*
	 * before relocating, we have to setup RAM timing
	 * because memory timing is board-dependend, you will
	 * find a lowlevel_init.S in your board directory.
	 */
	bl	lowlevel_init
#endif

	bl	_main

/*------------------------------------------------------------------------------*/

	.globl	c_runtime_cpu_setup
c_runtime_cpu_setup:

	bx	lr

/*
 *************************************************************************
 *
 * CPU_init_critical registers
 *
 * setup important registers
 * setup memory timing
 *
 *************************************************************************
 */

#define INTCON (0x01c00000+0x200000)
#define INTMSK (0x01c00000+0x20000c)
#define LOCKTIME (0x01c00000+0x18000c)
#define PLLCON (0x01c00000+0x180000)
#define CLKCON (0x01c00000+0x180004)
#define WTCON (0x01c00000+0x130000)
cpu_init_crit:
	/* disable watch dog */
	ldr	r0, =WTCON
	ldr	r1, =0x0
	str	r1, [r0]

	/*
	 * mask all IRQs by clearing all bits in the INTMRs
	 */
	ldr	r1,=INTMSK
	ldr	r0, =0x03fffeff
	str	r0, [r1]

	ldr	r1, =INTCON
	ldr	r0, =0x05
	str	r0, [r1]

	/* Set Clock Control Register */
	ldr	r1, =LOCKTIME
	ldrb	r0, =800
	strb	r0, [r1]

	ldr	r1, =PLLCON

#if CONFIG_S3C44B0_CLOCK_SPEED==66
	ldr	r0, =0x34031	/* 66MHz (Quartz=11MHz) */
#elif CONFIG_S3C44B0_CLOCK_SPEED==75
	ldr	r0, =0x610c1 /*B2: Xtal=20mhz Fclk=75MHz  */
#else
# error CONFIG_S3C44B0_CLOCK_SPEED undefined
#endif

	str	r0, [r1]

	ldr	r1,=CLKCON
	ldr	r0, =0x7ff8
	str	r0, [r1]

	mov	pc, lr


/*************************************************/
/*	interrupt vectors	*/
/*************************************************/
real_vectors:
	b	reset
	b	undefined_instruction
	b	software_interrupt
	b	prefetch_abort
	b	data_abort
	b	not_used
	b	irq
	b	fiq

/*************************************************/

undefined_instruction:
	mov	r6, #3
	b	reset

software_interrupt:
	mov	r6, #4
	b	reset

prefetch_abort:
	mov	r6, #5
	b	reset

data_abort:
	mov	r6, #6
	b	reset

not_used:
	/* we *should* never reach this */
	mov	r6, #7
	b	reset

irq:
	mov	r6, #8
	b	reset

fiq:
	mov	r6, #9
	b	reset