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
|
/*
ChibiOS/RT - Copyright (C) 2006-2007 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT 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 3 of the License, or
(at your option) any later version.
ChibiOS/RT 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, see <http://www.gnu.org/licenses/>.
*/
#include <ch.h>
#include "lpc214x.h"
/*
* System idle thread loop.
*/
void _IdleThread(void *p) {
while (TRUE) {
// Note, it is disabled because it causes trouble with the JTAG probe.
// Enable it in the final code only.
// PCON = 1;
}
}
/*
* The following functions are present only if there is in the system any
* code compiled as THUMB that may invoke them.
* NOTE: The undefs are there in case this module is compiled in ARM mode but
* there are THUMB modules in the system.
*/
#ifdef THUMB_PRESENT
#undef chSysLock
void chSysLock(void) {
#ifdef THUMB
asm(".p2align 2,, \n\t" \
"mov r0, pc \n\t" \
"bx r0 \n\t" \
".code 32 \n\t");
#endif
asm("msr CPSR_c, #0x9F \n\t" \
"bx lr \n\t");
}
#undef chSysUnlock
void chSysUnlock(void) {
#ifdef THUMB
asm(".p2align 2,, \n\t" \
"mov r0, pc \n\t" \
"bx r0 \n\t" \
".code 32 \n\t");
#endif
asm("msr CPSR_c, #0x1F \n\t" \
"bx lr \n\t");
}
#endif
void chSysSwitchI(Thread *otp, Thread *ntp) {
#ifdef THUMB
asm(".p2align 2,, \n\t" \
"mov r2, pc \n\t" \
"bx r2 \n\t" \
".code 32 \n\t");
#endif
#ifdef CH_CURRP_REGISTER_CACHE
asm("stmfd sp!, {r4, r5, r6, r8, r9, r10, r11, lr} \n\t" \
"str sp, [r0, #16] \n\t" \
"ldr sp, [r1, #16] \n\t");
#ifdef THUMB_PRESENT
asm("ldmfd sp!, {r4, r5, r6, r8, r9, r10, r11, lr} \n\t" \
"bx lr \n\t");
#else /* !THUMB_PRESENT */
asm("ldmfd sp!, {r4, r5, r6, r8, r9, r10, r11, pc} \n\t");
#endif /* !THUMB_PRESENT */
#else /* !CH_CURRP_REGISTER_CACHE */
asm("stmfd sp!, {r4, r5, r6, r7, r8, r9, r10, r11, lr} \n\t" \
"str sp, [r0, #16] \n\t" \
"ldr sp, [r1, #16] \n\t");
#ifdef THUMB_PRESENT
asm("ldmfd sp!, {r4, r5, r6, r7, r8, r9, r10, r11, lr} \n\t" \
"bx lr \n\t");
#else /* !THUMB_PRESENT */
asm("ldmfd sp!, {r4, r5, r6, r7, r8, r9, r10, r11, pc} \n\t");
#endif /* !THUMB_PRESENT */
#endif /* !CH_CURRP_REGISTER_CACHE */
}
/*
* System console message (not implemented).
*/
void chSysPuts(char *msg) {
}
/*
* Common IRQ exit code, \p chSysIRQExitI() just jumps here.
*
* System stack frame structure after a context switch in the
* interrupt handler:
*
* High +------------+
* | LR_USR | -+
* | R12 | |
* | R3 | |
* | R2 | | External context: IRQ handler frame
* | R1 | |
* | R0 | |
* | LR_IRQ | | (user code return address)
* | SPSR | -+ (user code status)
* | .... | <- chSchDoRescheduleI() stack frame, optimize it for space
* | LR | -+ (system code return address)
* | R11 | |
* | R10 | |
* | R9 | |
* | R8 | | Internal context: chSysSwitchI() frame
* | (R7) | | (optional, see CH_CURRP_REGISTER_CACHE)
* | R6 | |
* | R5 | |
* SP-> | R4 | -+
* Low +------------+
*/
__attribute__((naked, weak))
void IrqCommon(void) {
register BOOL b asm("r0");
VICVectAddr = 0;
b = chSchRescRequiredI();
#ifdef THUMB
asm(".p2align 2,, \n\t" \
"mov lr, pc \n\t" \
"bx lr \n\t" \
".code 32 \n\t");
#endif
/*
* If a reschedulation is not required then just returns from the IRQ.
*/
asm("cmp r0, #0 \n\t" \
"ldmeqfd sp!, {r0-r3, r12, lr} \n\t" \
"subeqs pc, lr, #4 \n\t");
/*
* Reschedulation required, saves the external context on the
* system/user stack and empties the IRQ stack.
*/
asm(".set MODE_IRQ, 0x12 \n\t" \
".set MODE_SYS, 0x1F \n\t" \
".set F_BIT, 0x40 \n\t" \
".set I_BIT, 0x80 \n\t" \
"ldmfd sp!, {r0-r3, r12, lr} \n\t" \
"msr CPSR_c, #MODE_SYS | I_BIT \n\t" \
"stmfd sp!, {r0-r3, r12, lr} \n\t" \
"msr CPSR_c, #MODE_IRQ | I_BIT \n\t" \
"mrs r0, SPSR \n\t" \
"mov r1, lr \n\t" \
"msr CPSR_c, #MODE_SYS | I_BIT \n\t" \
"stmfd sp!, {r0, r1} \n\t");
#ifdef THUMB_NO_INTERWORKING
asm("add r0, pc, #1 \n\t" \
"bx r0 \n\t" \
".code 16 \n\t" \
"bl chSchDoRescheduleI \n\t" \
".p2align 2,, \n\t" \
"mov lr, pc \n\t" \
"bx lr \n\t" \
".code 32 \n\t");
#else
asm("bl chSchDoRescheduleI \n\t");
#endif
/*
* Restores the external context.
*/
asm("ldmfd sp!, {r0, r1} \n\t" \
"msr CPSR_c, #MODE_IRQ | I_BIT \n\t" \
"msr SPSR_fsxc, r0 \n\t" \
"mov lr, r1 \n\t" \
"msr CPSR_c, #MODE_SYS | I_BIT \n\t" \
"ldmfd sp!, {r0-r3, r12, lr} \n\t" \
"msr CPSR_c, #MODE_IRQ | I_BIT \n\t" \
"subs pc, lr, #4 \n\t");
/*
* Threads entry/exit code. It is declared weak so you can easily replace it.
* NOTE: It is always invoked in ARM mode, it does the mode switching.
* NOTE: It is included into IrqCommon to make sure the symbol refers to
* 32 bit code.
*/
asm(".weak threadstart \n\t" \
".globl threadstart \n\t" \
"threadstart: \n\t" \
"msr CPSR_c, #MODE_SYS \n\t");
#ifndef THUMB_NO_INTERWORKING
asm("mov r0, r5 \n\t" \
"mov lr, pc \n\t" \
"bx r4 \n\t" \
"bl chThdExit \n\t");
#else
asm("add r0, pc, #1 \n\t" \
"bx r0 \n\t" \
".code 16 \n\t" \
"mov r0, r5 \n\t" \
"bl jmpr4 \n\t" \
"bl chThdExit \n\t" \
"jmpr4: \n\t" \
"bx r4 \n\t");
#endif
}
/*
* System halt.
*/
__attribute__((naked, weak))
void chSysHalt(void) {
#ifdef THUMB
asm("ldr r0, =_halt32 \n\t" \
"bx r0 \n\t");
#endif
asm("b _halt32 \n\t");
}
|
