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
|
/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id: crt0.S 18776 2008-10-11 18:32:17Z gevaerts $
*
* Copyright (C) 2008 by Marcoen Hirschberg
* Copyright (C) 2008 by Denes Balatoni
*
* 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#define ASM
#include "config.h"
#include "cpu.h"
.section .intvect,"ax",%progbits
.global start
.global _newstart
/* Exception vectors */
start:
b _newstart
ldr pc, =undef_instr_handler
ldr pc, =software_int_handler
ldr pc, =prefetch_abort_handler
ldr pc, =data_abort_handler
ldr pc, =reserved_handler
ldr pc, =irq_handler
ldr pc, =fiq_handler
.ltorg
_newstart:
#if !defined(BOOTLOADER)
ldr pc, =newstart2 // we do not want to execute from 0x0 as iram will be mapped there
.section .init.text,"ax",%progbits
newstart2:
#endif
msr cpsr_c, #0xd3 /* enter supervisor mode, disable IRQ/FIQ */
#ifdef BOOTLOADER
/* Relocate ourself to IRAM1 - we have been loaded to IRAM0 */
ldr r0, =_dfuloadaddr
ldr r1, =_movestart
ldr r2, =_moveend
1:
ldmia r0!, {r3-r10}
stmia r1!, {r3-r10}
cmp r1, r2
blt 1b
ldr pc, =start_loc /* jump to the relocated start_loc: */
.section .init.text,"ax",%progbits
.global start_loc
start_loc:
#endif
mrc p15, 0, r0, c1, c0, 0
bic r0, r0, #0x1000
bic r0, r0, #0x5
mcr p15, 0, r0, c1, c0, 0 /* disable caches and protection unit */
.cleancache:
mrc p15, 0, r15, c7, c10, 3 /* test and clean dcache */
bne .cleancache
mov r0, #0
mcr p15, 0, r0, c7, c10, 4 /* drain write buffer */
mcr p15, 0, r0, c7, c5, 0 /* invalidate icache */
/* reset VIC controller */
ldr r1, =0x38e00000
add r2, r1, #0x00001000
add r3, r1, #0x00002000
sub r4, r0, #1
str r4, [r1,#0x14]
str r4, [r2,#0x14]
str r4, [r1,#0xf00]
str r4, [r2,#0xf00]
str r4, [r3,#0x08]
str r4, [r3,#0x0c]
str r0, [r1,#0x14]
str r0, [r2,#0x14]
#if defined(BOOTLOADER)
/* SPI speed is limited when icache is not active. Not worth
* activating dcache, it is almost useless on pre-init stage
* and the TLB needs 16Kb in detriment of the bootloader.
*/
mrc p15, 0, r0, c1, c0, 0
orr r0, r0, #1<<12 /* enable icache */
mcr p15, 0, r0, c1, c0, 0
#else
bl memory_init
/* Copy interrupt vectors to iram */
ldr r2, =_intvectstart
ldr r3, =_intvectend
ldr r4, =_intvectcopy
1:
cmp r3, r2
ldrhi r1, [r4], #4
strhi r1, [r2], #4
bhi 1b
/* Initialise bss section to zero */
ldr r2, =_edata
ldr r3, =_end
mov r4, #0
1:
cmp r3, r2
strhi r4, [r2], #4
bhi 1b
/* Copy icode and data to ram */
ldr r2, =_iramstart
ldr r3, =_iramend
ldr r4, =_iramcopy
1:
cmp r3, r2
ldrhi r1, [r4], #4
strhi r1, [r2], #4
bhi 1b
/* Initialise ibss section to zero */
ldr r2, =_iedata
ldr r3, =_iend
mov r4, #0
1:
cmp r3, r2
strhi r4, [r2], #4
bhi 1b
#endif
/* Set up stack for IRQ mode */
msr cpsr_c, #0xd2
ldr sp, =_irqstackend
/* Set up stack for FIQ mode */
msr cpsr_c, #0xd1
ldr sp, =_fiqstackend
/* Let svc, abort and undefined modes use irq stack */
msr cpsr_c, #0xd3
ldr sp, =_irqstackend
msr cpsr_c, #0xd7
ldr sp, =_irqstackend
msr cpsr_c, #0xdb
ldr sp, =_irqstackend
/* Switch to sys mode */
msr cpsr_c, #0xdf
/* Set up some stack and munge it with 0xdeadbeef */
ldr sp, =stackend
ldr r2, =stackbegin
ldr r3, =0xdeadbeef
1:
cmp sp, r2
strhi r3, [r2], #4
bhi 1b
b main
#ifdef BOOTLOADER
/* Initialise bss section to zero */
.global bss_init
.type bss_init, %function
bss_init:
stmfd sp!, {r4-r9,lr}
ldr r0, =_edata
ldr r1, =_end
mov r2, #0
mov r3, #0
mov r4, #0
mov r5, #0
mov r6, #0
mov r7, #0
mov r8, #0
mov r9, #0
b 2f
.align 5 /* cache line size */
1:
stmia r0!, {r2-r9}
2:
cmp r0, r1
blt 1b
ldmpc regs=r4-r9
.ltorg
#endif
|
