summaryrefslogtreecommitdiff
path: root/bsp/raspberry-pi/raspi3-32/cpu/start_gcc.S
blob: 82ff831331ab8e9dd0b65e7a769a3d76f0976fea (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
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
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
/*
 * Copyright (c) 2006-2019, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2013-07-05     Bernard      the first version
 * 2019-07-28     zdzn         add smp support
 */

#include "../rtconfig.h"
.equ Mode_USR,        0x10
.equ Mode_FIQ,        0x11
.equ Mode_IRQ,        0x12
.equ Mode_SVC,        0x13
.equ Mode_ABT,        0x17
.equ Mode_UND,        0x1B
.equ Mode_SYS,        0x1F

.equ I_Bit,           0x80            @ when I bit is set, IRQ is disabled
.equ F_Bit,           0x40            @ when F bit is set, FIQ is disabled

#ifdef RT_USING_FPU
.equ UND_Stack_Size,     0x00000400
#else
.equ UND_Stack_Size,     0x00000000
#endif
.equ SVC_Stack_Size,     0x00000400
.equ ABT_Stack_Size,     0x00000000
.equ RT_FIQ_STACK_PGSZ,  0x00000000
.equ RT_IRQ_STACK_PGSZ,  0x00000800
.equ USR_Stack_Size,     0x00000400

#define ISR_Stack_Size  (UND_Stack_Size + SVC_Stack_Size + ABT_Stack_Size + \
                 RT_FIQ_STACK_PGSZ + RT_IRQ_STACK_PGSZ)

.section .data.share.isr
/* stack */

#ifdef RT_USING_SMP
.globl stack_start0
.globl stack_top0
.globl stack_start1
.globl stack_top1
.globl stack_start2
.globl stack_top2
.globl stack_start3
.globl stack_top3
stack_start0:
.rept ISR_Stack_Size
.byte 0
.endr
stack_top0:

stack_start1:
.rept ISR_Stack_Size
.byte 0
.endr
stack_top1:

stack_start2:
.rept ISR_Stack_Size
.byte 0
.endr
stack_top2:

stack_start3:
.rept ISR_Stack_Size
.byte 0
.endr
stack_top3:

.globl boot_indicate
boot_indicate:
.rept 16
.byte 0
.endr

#else
.globl stack_start
.globl stack_top
stack_start:
.rept ISR_Stack_Size
.byte 0
.endr
stack_top:
#endif


.text
/* reset entry */
.globl _reset
_reset:

    /* Disable IRQ & FIQ */
    cpsid if

    /* Check for HYP mode */
    mrs r0, cpsr_all
    and r0, r0, #0x1F
    mov r8, #0x1A
    cmp r0, r8
    beq overHyped
    b continue

overHyped: /* Get out of HYP mode */
    ldr r1, =continue
    msr ELR_hyp, r1
    mrs r1, cpsr_all
    and r1, r1, #0x1f    ;@ CPSR_MODE_MASK
    orr r1, r1, #0x13    ;@ CPSR_MODE_SUPERVISOR
    msr SPSR_hyp, r1
    eret

continue:

    /* disable mmu */
    bl      rt_cpu_mmu_disable
    /* set the cpu to SVC32 mode and disable interrupt */
    mrs     r0, cpsr
    bic     r0, r0, #0x1f
    orr     r0, r0, #0x13
    msr     cpsr_c, r0
#ifdef RT_USING_SMP
    mrc     p15, 0, r0, c0, c0, 5
    ubfx    r0, r0, #0, #2
    cmp     r0, #0
    beq     1f
    /* write boot indicate */
    ldr     r5, = boot_indicate
    str     r0, [r5, r0, lsl #2]
    bl secondary_cpu_start
    b .
1:
#endif
    /* setup stack */
#ifdef RT_USING_SMP
    ldr     r0, =stack_top0
#else
    ldr     r0, =stack_top
#endif
    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                  */
    bl rt_hw_init_mmu_table
    bl init_mbox_mmu_map
    bl rt_hw_mmu_init

    /* start RT-Thread Kernel */
    ldr     pc, _rtthread_startup
_rtthread_startup:
    .word rtthread_startup

stack_setup:

    @  Set the startup stack for svc
    mov     sp, r0

    @  Enter Undefined Instruction Mode and set its Stack Pointer
    msr     cpsr_c, #Mode_UND|I_Bit|F_Bit
    mov     sp, r0
    sub     r0, r0, #UND_Stack_Size

    @  Enter Abort Mode and set its Stack Pointer
    msr     cpsr_c, #Mode_ABT|I_Bit|F_Bit
    mov     sp, r0
    sub     r0, r0, #ABT_Stack_Size

    @  Enter FIQ Mode and set its Stack Pointer
    msr     cpsr_c, #Mode_FIQ|I_Bit|F_Bit
    mov     sp, r0
    sub     r0, r0, #RT_FIQ_STACK_PGSZ

    @  Enter IRQ Mode and set its Stack Pointer
    msr     cpsr_c, #Mode_IRQ|I_Bit|F_Bit
    mov     sp, r0
    sub     r0, r0, #RT_IRQ_STACK_PGSZ

    /* come back to SVC mode */
    msr     cpsr_c, #Mode_SVC|I_Bit|F_Bit
    bx      lr

.text

/* exception handlers: undef, swi, padt, dabt, resv, irq, fiq          */
.section .text.isr, "ax"
    .align  5
.globl vector_fiq
vector_fiq:
    stmfd   sp!,{r0-r7,lr}
    bl      rt_hw_trap_fiq
    ldmfd   sp!,{r0-r7,lr}
    subs    pc, lr, #4

.globl      rt_interrupt_enter
.globl      rt_interrupt_leave
.globl      rt_thread_switch_interrupt_flag
.globl      rt_interrupt_from_thread
.globl      rt_interrupt_to_thread

.globl      rt_current_thread
.globl      vmm_thread
.globl      vmm_virq_check

    .align  5
.globl vector_irq
vector_irq:
#ifdef RT_USING_SMP
    clrex
      
    stmfd   sp!, {r0, r1}
    cps     #Mode_SVC
    mov     r0, sp          /* svc_sp */
    mov     r1, lr          /* svc_lr */

    cps     #Mode_IRQ
    sub     lr, lr, #4
    stmfd   r0!, {r1, lr}       /* svc_lr, svc_pc */
    stmfd   r0!, {r2 - r12}
    ldmfd   sp!, {r1, r2}     /* original r0, r1 */
    stmfd   r0!, {r1 - r2}
    mrs     r1,  spsr         /* original mode */
    stmfd   r0!, {r1}

#ifdef RT_USING_SMART
    stmfd   r0, {r13, r14}^ /* usr_sp, usr_lr */
    sub   r0, #8
#endif
#ifdef RT_USING_FPU
    /* fpu context */
    vmrs r6, fpexc
    tst  r6, #(1<<30)
    beq 1f
    vstmdb r0!, {d0-d15}
    vstmdb r0!, {d16-d31}
    vmrs r5, fpscr
    stmfd r0!, {r5}
1:
    stmfd r0!, {r6}
#endif
    mov     r8, r0

    bl      rt_interrupt_enter
    bl      rt_hw_trap_irq
    bl      rt_interrupt_leave
    
    cps     #Mode_SVC
    mov     sp, r8
    mov     r0, r8
    
    bl      rt_scheduler_do_irq_switch

    b       rt_hw_context_switch_exit

#else
    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
    @ rt_hw_context_switch_interrupt_do and don't return
    ldr     r0, =rt_thread_switch_interrupt_flag
    ldr     r1, [r0]
    cmp     r1, #1
    beq     rt_hw_context_switch_interrupt_do

    ldmfd   sp!, {r0-r12,lr}
    subs    pc,  lr, #4

rt_hw_context_switch_interrupt_do:
    mov     r1,  #0         @ clear flag
    str     r1,  [r0]

    mov     r1, sp          @ r1 point to {r0-r3} in stack
    add     sp, sp, #4*4
    ldmfd   sp!, {r4-r12,lr}@ reload saved registers
    mrs     r0,  spsr       @ get cpsr of interrupt thread
    sub     r2,  lr, #4     @ save old task's pc to r2

    @ Switch to SVC mode with no interrupt. If the usr mode guest is
    @ interrupted, this will just switch to the stack of kernel space.
    @ save the registers in kernel space won't trigger data abort.
    msr     cpsr_c, #I_Bit|F_Bit|Mode_SVC

    stmfd   sp!, {r2}       @ push old task's pc
    stmfd   sp!, {r4-r12,lr}@ push old task's lr,r12-r4
    ldmfd   r1,  {r1-r4}    @ restore r0-r3 of the interrupt thread
    stmfd   sp!, {r1-r4}    @ push old task's r0-r3
    stmfd   sp!, {r0}       @ push old task's cpsr

#ifdef RT_USING_SMART
    stmfd sp, {r13, r14}^  @push usr_sp, usr_lr
    sub sp, #8
#endif
#ifdef RT_USING_FPU
    /* fpu context */
    vmrs r6, fpexc
    tst  r6, #(1<<30)
    beq 1f
    vstmdb sp!, {d0-d15}
    vstmdb sp!, {d16-d31}
    vmrs r5, fpscr
    stmfd sp!, {r5}
1:
    stmfd sp!, {r6}
#endif

    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

#ifdef RT_USING_FPU
/* fpu context */
    ldmfd sp!, {r6}
    vmsr fpexc, r6
    tst  r6, #(1<<30)
    beq 1f
    ldmfd sp!, {r5}
    vmsr fpscr, r5
    vldmia sp!, {d16-d31}
    vldmia sp!, {d0-d15}
1:
#endif

#ifdef RT_USING_SMART
    ldmfd sp, {r13, r14}^  @pop usr_sp, usr_lr
    add sp, #8
#endif

    ldmfd   sp!, {r4}       @ pop new task's cpsr to spsr
    msr     spsr_cxsf, r4

    ldmfd   sp!, {r0-r12,lr,pc}^ @ pop new task's r0-r12,lr & pc, copy spsr to cpsr

#endif

.macro push_svc_reg
    sub     sp, sp, #17 * 4         @/* Sizeof(struct rt_hw_exp_stack)  */
    stmia   sp, {r0 - r12}          @/* Calling r0-r12                  */
    mov     r0, sp
    mrs     r6, spsr                @/* Save CPSR                       */
    str     lr, [r0, #15*4]         @/* Push PC                         */
    str     r6, [r0, #16*4]         @/* Push CPSR                       */
    cps     #Mode_SVC
    str     sp, [r0, #13*4]         @/* Save calling SP                 */
    str     lr, [r0, #14*4]         @/* Save calling PC                 */
.endm

    .align  5
    .globl  vector_swi
vector_swi:
    push_svc_reg
    bl      rt_hw_trap_swi
    b       .

    .align  5
    .globl  vector_undef
vector_undef:
    push_svc_reg
    cps #Mode_UND
    bl      rt_hw_trap_undef
#ifdef RT_USING_FPU
    ldr     lr, [sp, #15*4]
    ldmia   sp, {r0 - r12}
    add     sp, sp, #17 * 4
    movs    pc, lr
#endif
    b       .

    .align  5
    .globl  vector_pabt
vector_pabt:
    push_svc_reg
    bl      rt_hw_trap_pabt
    b       .

    .align  5
    .globl  vector_dabt
vector_dabt:
    push_svc_reg
    bl      rt_hw_trap_dabt
    b       .

    .align  5
    .globl  vector_resv
vector_resv:
    push_svc_reg
    bl      rt_hw_trap_resv
    b       .

#ifdef RT_USING_SMP

.global secondary_cpu_start
secondary_cpu_start:
    /* set vector base */
    mrc p15, 0, r0, c1, c0, 0        
    bic r0, #(1<<13)
    mcr p15, 0, r0, c1, c0, 0
    
    /* setup stack */
    mrc p15, 0, r0, c0, c0, 5
    ubfx    r0, r0, #0, #2
    ldr r1, =stack_top0
    ldr r2, =ISR_Stack_Size
    mul r3, r2, r0
    add r0, r1, r3
    bl  stack_setup
    /* initialize the mmu table and enable mmu */
    bl  rt_hw_mmu_init
    b   secondary_cpu_c_start

#endif

;@ void arm_smp_enable(void);
.globl arm_smp_enable
arm_smp_enable:
    mrc p15, 0, r0, c1, c0, 1   ;@ set SMP bit in ACTLR
    orr r0, r0, #0x40
    mcr p15, 0, r0, c1, c0, 1
    bx lr
/*
    mrrc p15, 1, r0, r1, c15
    orr r0, r0, #0x40
    mcrr p15, 1, r0, r1, c15
    dsb
    isb
    bx lr
*/
.text
;@ void arm_smp_disable(void);
.globl arm_smp_disable

arm_smp_disable:
    mrc p15, 0, r0, c1, c0, 1   ;@ clear SMP bit in ACTLR
    bic r0, r0, #0x40
    mcr p15, 0, r0, c1, c0, 1
    bx lr
/*
    mrrc p15, 1, r0, r1, c15
    bic r0, r0, #0x40
    mcrr p15, 1, r0, r1, c15
    bx lr
*/