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
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
|
/*
* File : start.S
* This file is part of RT-Thread RTOS
* COPYRIGHT (C) 2006, RT-Thread Development Team
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http:/*openlab.rt-thread.com/license/LICENSE
*
* Change Logs:
* Date Author Notes
* 2006-03-13 Bernard first version
* 2006-10-05 Alsor.Z for s3c2440 initialize
* 2008-01-29 Yi.Qiu for QEMU emulator
*/
#define CONFIG_STACKSIZE 512
#define S_FRAME_SIZE 72
#define S_OLD_R0 68
#define S_PSR 64
#define S_PC 60
#define S_LR 56
#define S_SP 52
#define S_IP 48
#define S_FP 44
#define S_R10 40
#define S_R9 36
#define S_R8 32
#define S_R7 28
#define S_R6 24
#define S_R5 20
#define S_R4 16
#define S_R3 12
#define S_R2 8
#define S_R1 4
#define S_R0 0
.equ USERMODE, 0x10
.equ FIQMODE, 0x11
.equ IRQMODE, 0x12
.equ SVCMODE, 0x13
.equ ABORTMODE, 0x17
.equ UNDEFMODE, 0x1b
.equ MODEMASK, 0x1f
.equ NOINT, 0xc0
.equ RAM_BASE, 0x00000000 /*Start address of RAM */
.equ ROM_BASE, 0x30000000 /*Start address of Flash */
.equ MPLLCON, 0x4c000004 /*Mpll control register */
.equ M_MDIV, 0x20
.equ M_PDIV, 0x4
.equ M_SDIV, 0x2
.equ INTMSK, 0x4a000008
.equ INTSUBMSK, 0x4a00001c
.equ WTCON, 0x53000000
.equ LOCKTIME, 0x4c000000
.equ CLKDIVN, 0x4c000014 /*Clock divider control */
.equ GPHCON, 0x56000070 /*Port H control */
.equ GPHUP, 0x56000078 /*Pull-up control H */
.equ BWSCON, 0x48000000 /*Bus width & wait status */
.equ BANKCON0, 0x48000004 /*Boot ROM control */
.equ BANKCON1, 0x48000008 /*BANK1 control */
.equ BANKCON2, 0x4800000c /*BANK2 cControl */
.equ BANKCON3, 0x48000010 /*BANK3 control */
.equ BANKCON4, 0x48000014 /*BANK4 control */
.equ BANKCON5, 0x48000018 /*BANK5 control */
.equ BANKCON6, 0x4800001c /*BANK6 control */
.equ BANKCON7, 0x48000020 /*BANK7 control */
.equ REFRESH, 0x48000024 /*DRAM/SDRAM efresh */
.equ BANKSIZE, 0x48000028 /*Flexible Bank Size */
.equ MRSRB6, 0x4800002c /*Mode egister set for SDRAM*/
.equ MRSRB7, 0x48000030 /*Mode egister set for SDRAM*/
/*
*************************************************************************
*
* Jump vector table
*
*************************************************************************
*/
.section .init, "ax"
.code 32
.globl _start
_start:
b reset
ldr pc, _vector_undef
ldr pc, _vector_swi
ldr pc, _vector_pabt
ldr pc, _vector_dabt
ldr pc, _vector_resv
ldr pc, _vector_irq
ldr pc, _vector_fiq
_vector_undef: .word vector_undef
_vector_swi: .word vector_swi
_vector_pabt: .word vector_pabt
_vector_dabt: .word vector_dabt
_vector_resv: .word vector_resv
_vector_irq: .word vector_irq
_vector_fiq: .word vector_fiq
.balignl 16,0xdeadbeef
/*
*************************************************************************
*
* Startup Code (reset vector)
* relocate armboot to ram
* setup stack
* jump to second stage
*
*************************************************************************
*/
_TEXT_BASE:
.word TEXT_BASE
/*
* rtthread kernel start and end
* which are defined in linker script
*/
.globl _rtthread_start
_rtthread_start:
.word _start
.globl _rtthread_end
_rtthread_end:
.word _end
/*
* rtthread bss start and end which are defined in linker script
*/
.globl _bss_start
_bss_start:
.word __bss_start
.globl _bss_end
_bss_end:
.word __bss_end
/* IRQ stack memory (calculated at run-time) */
.globl IRQ_STACK_START
IRQ_STACK_START:
.word _irq_stack_start + 1024
.globl FIQ_STACK_START
FIQ_STACK_START:
.word _fiq_stack_start + 1024
.globl UNDEFINED_STACK_START
UNDEFINED_STACK_START:
.word _undefined_stack_start + CONFIG_STACKSIZE
.globl ABORT_STACK_START
ABORT_STACK_START:
.word _abort_stack_start + CONFIG_STACKSIZE
.globl _STACK_START
_STACK_START:
.word _svc_stack_start + 4096
/* ----------------------------------entry------------------------------*/
reset:
/* set the cpu to SVC32 mode */
mrs r0,cpsr
bic r0,r0,#MODEMASK
orr r0,r0,#SVCMODE
msr cpsr,r0
/* watch dog disable */
ldr r0,=WTCON
ldr r1,=0x0
str r1,[r0]
/* mask all IRQs by clearing all bits in the INTMRs */
ldr r1, =INTMSK
ldr r0, =0xffffffff
str r0, [r1]
ldr r1, =INTSUBMSK
ldr r0, =0x7fff /*all sub interrupt disable */
str r0, [r1]
/* set interrupt vector */
ldr r0, _load_address
mov r1, #0x0 /* target address */
add r2, r0, #0x20 /* size, 32bytes */
copy_loop:
ldmia r0!, {r3-r10} /* copy from source address [r0] */
stmia r1!, {r3-r10} /* copy to target address [r1] */
cmp r0, r2 /* until source end addreee [r2] */
ble copy_loop
/* setup stack */
bl stack_setup
/* clear .bss */
mov r0,#0 /* get a zero */
ldr r1,=__bss_start /* bss start */
ldr r2,=__bss_end /* bss end */
bss_loop:
cmp r1,r2 /* check if data to clear */
strlo r0,[r1],#4 /* clear 4 bytes */
blo bss_loop /* loop until done */
/* call C++ constructors of global objects */
ldr r0, =__ctors_start__
ldr r1, =__ctors_end__
ctor_loop:
cmp r0, r1
beq ctor_end
ldr r2, [r0], #4
stmfd sp!, {r0-r1}
mov lr, pc
bx r2
ldmfd sp!, {r0-r1}
b ctor_loop
ctor_end:
/* start RT-Thread Kernel */
ldr pc, _rtthread_startup
_rtthread_startup:
.word rtthread_startup
#if defined (__FLASH_BUILD__)
_load_address:
.word ROM_BASE + _TEXT_BASE
#else
_load_address:
.word RAM_BASE + _TEXT_BASE
#endif
/*
*************************************************************************
*
* Interrupt handling
*
*************************************************************************
*/
/* exception handlers */
.align 5
vector_undef:
sub sp, sp, #S_FRAME_SIZE
stmia sp, {r0 - r12} /* Calling r0-r12 */
add r8, sp, #S_PC
stmdb r8, {sp, lr}^ /* Calling SP, LR */
str lr, [r8, #0] /* Save calling PC */
mrs r6, spsr
str r6, [r8, #4] /* Save CPSR */
str r0, [r8, #8] /* Save OLD_R0 */
mov r0, sp
bl rt_hw_trap_udef
.align 5
vector_swi:
bl rt_hw_trap_swi
.align 5
vector_pabt:
bl rt_hw_trap_pabt
.align 5
vector_dabt:
sub sp, sp, #S_FRAME_SIZE
stmia sp, {r0 - r12} /* Calling r0-r12 */
add r8, sp, #S_PC
stmdb r8, {sp, lr}^ /* Calling SP, LR */
str lr, [r8, #0] /* Save calling PC */
mrs r6, spsr
str r6, [r8, #4] /* Save CPSR */
str r0, [r8, #8] /* Save OLD_R0 */
mov r0, sp
bl rt_hw_trap_dabt
.align 5
vector_resv:
bl rt_hw_trap_resv
.globl rt_interrupt_enter
.globl rt_interrupt_leave
.globl rt_thread_switch_interrupt_flag
.globl rt_interrupt_from_thread
.globl rt_interrupt_to_thread
vector_irq:
stmfd sp!, {r0-r12,lr}
bl rt_interrupt_enter
bl rt_hw_trap_irq
bl rt_interrupt_leave
/* if rt_thread_switch_interrupt_flag set, jump to _interrupt_thread_switch and don't return */
ldr r0, =rt_thread_switch_interrupt_flag
ldr r1, [r0]
cmp r1, #1
beq _interrupt_thread_switch
ldmfd sp!, {r0-r12,lr}
subs pc, lr, #4
.align 5
vector_fiq:
stmfd sp!,{r0-r7,lr}
bl rt_hw_trap_fiq
ldmfd sp!,{r0-r7,lr}
subs pc,lr,#4
_interrupt_thread_switch:
mov r1, #0 /* clear rt_thread_switch_interrupt_flag*/
str r1, [r0]
ldmfd sp!, {r0-r12,lr} /* reload saved registers */
stmfd sp!, {r0-r3} /* save r0-r3 */
mov r1, sp
add sp, sp, #16 /* restore sp */
sub r2, lr, #4 /* save old task's pc to r2 */
mrs r3, spsr /* disable interrupt */
orr r0, r3, #NOINT
msr spsr_c, r0
ldr r0, =.+8 /* switch to interrupted task's stack*/
movs pc, r0
stmfd sp!, {r2} /* push old task's pc */
stmfd sp!, {r4-r12,lr} /* push old task's lr,r12-r4 */
mov r4, r1 /* Special optimised code below */
mov r5, r3
ldmfd r4!, {r0-r3}
stmfd sp!, {r0-r3} /* push old task's r3-r0 */
stmfd sp!, {r5} /* push old task's psr */
mrs r4, spsr
stmfd sp!, {r4} /* push old task's spsr */
ldr r4, =rt_interrupt_from_thread
ldr r5, [r4]
str sp, [r5] /* store sp in preempted tasks's TCB*/
ldr r6, =rt_interrupt_to_thread
ldr r6, [r6]
ldr sp, [r6] /* get new task's stack pointer */
ldmfd sp!, {r4} /* pop new task's spsr */
msr SPSR_cxsf, r4
ldmfd sp!, {r4} /* pop new task's psr */
msr CPSR_cxsf, r4
ldmfd sp!, {r0-r12,lr,pc} /* pop new task's r0-r12,lr & pc */
stack_setup:
mrs r0, cpsr
bic r0, r0, #MODEMASK
orr r1, r0, #UNDEFMODE|NOINT
msr cpsr_cxsf, r1 /* undef mode */
ldr sp, UNDEFINED_STACK_START
orr r1,r0,#ABORTMODE|NOINT
msr cpsr_cxsf,r1 /* abort mode */
ldr sp, ABORT_STACK_START
orr r1,r0,#IRQMODE|NOINT
msr cpsr_cxsf,r1 /* IRQ mode */
ldr sp, IRQ_STACK_START
orr r1,r0,#FIQMODE|NOINT
msr cpsr_cxsf,r1 /* FIQ mode */
ldr sp, FIQ_STACK_START
bic r0,r0,#MODEMASK
orr r1,r0,#SVCMODE|NOINT
msr cpsr_cxsf,r1 /* SVC mode */
ldr sp, _STACK_START
/* USER mode is not initialized. */
mov pc,lr /* The LR register may be not valid for the mode changes.*/
/*/*}*/
|
