1 /*
2 * FreeRTOS Kernel V11.1.0
3 * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
4 *
5 * SPDX-License-Identifier: MIT
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy of
8 * this software and associated documentation files (the "Software"), to deal in
9 * the Software without restriction, including without limitation the rights to
10 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
11 * the Software, and to permit persons to whom the Software is furnished to do so,
12 * subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in all
15 * copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
19 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
20 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
21 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 *
24 * https://www.FreeRTOS.org
25 * https://github.com/FreeRTOS
26 *
27 */
28
29 /*-----------------------------------------------------------
30 * Implementation of functions defined in portable.h for the RXv3 DPFPU port.
31 *----------------------------------------------------------*/
32
33 #warning Testing for DFPU support in this port is not yet complete
34
35 /* Scheduler includes. */
36 #include "FreeRTOS.h"
37 #include "task.h"
38
39 /* Library includes. */
40 #include "string.h"
41
42 /* Hardware specifics. */
43 #if ( configINCLUDE_PLATFORM_H_INSTEAD_OF_IODEFINE_H == 1 )
44
45 #include "platform.h"
46
47 #else /* configINCLUDE_PLATFORM_H_INSTEAD_OF_IODEFINE_H */
48
49 #include "iodefine.h"
50
51 #endif /* configINCLUDE_PLATFORM_H_INSTEAD_OF_IODEFINE_H */
52
53 /*-----------------------------------------------------------*/
54
55 /* Tasks should start with interrupts enabled and in Supervisor mode, therefore
56 * PSW is set with U and I set, and PM and IPL clear. */
57 #define portINITIAL_PSW ( ( StackType_t ) 0x00030000 )
58 #define portINITIAL_FPSW ( ( StackType_t ) 0x00000100 )
59 #define portINITIAL_DPSW ( ( StackType_t ) 0x00000100 )
60 #define portINITIAL_DCMR ( ( StackType_t ) 0x00000000 )
61 #define portINITIAL_DECNT ( ( StackType_t ) 0x00000001 )
62
63 /* Tasks are not created with a DPFPU context, but can be given a DPFPU context
64 * after they have been created. A variable is stored as part of the tasks context
65 * that holds portNO_DPFPU_CONTEXT if the task does not have a DPFPU context, or
66 * any other value if the task does have a DPFPU context. */
67 #define portNO_DPFPU_CONTEXT ( ( StackType_t ) 0 )
68 #define portHAS_DPFPU_CONTEXT ( ( StackType_t ) 1 )
69
70 /* The space on the stack required to hold the DPFPU data registers. This is 16
71 * 64-bit registers. */
72 #define portDPFPU_DATA_REGISTER_WORDS ( 16 * 2 )
73
74 /*-----------------------------------------------------------*/
75
76 /*
77 * Function to start the first task executing - written in asm code as direct
78 * access to registers is required.
79 */
80 static void prvStartFirstTask( void );
81
82 /*
83 * Software interrupt handler. Performs the actual context switch (saving and
84 * restoring of registers). Written in asm code as direct register access is
85 * required.
86 */
87 __interrupt void vSoftwareInterruptISR( void );
88
89 /*
90 * The tick ISR handler. The peripheral used is configured by the application
91 * via a hook/callback function.
92 */
93 __interrupt void vTickISR( void );
94
95 /*-----------------------------------------------------------*/
96
97 /* Saved as part of the task context. If ulPortTaskHasDPFPUContext is non-zero
98 * then a DPFPU context must be saved and restored for the task. */
99 #if ( configUSE_TASK_DPFPU_SUPPORT == 1 )
100
101 StackType_t ulPortTaskHasDPFPUContext = portNO_DPFPU_CONTEXT;
102
103 #endif /* configUSE_TASK_DPFPU_SUPPORT */
104
105 /* This is accessed by the inline assembler functions so is file scope for
106 * convenience. */
107 extern void * pxCurrentTCB;
108 extern void vTaskSwitchContext( void );
109
110 /*-----------------------------------------------------------*/
111
112 /*
113 * See header file for description.
114 */
pxPortInitialiseStack(StackType_t * pxTopOfStack,TaskFunction_t pxCode,void * pvParameters)115 StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
116 TaskFunction_t pxCode,
117 void * pvParameters )
118 {
119 /* R0 is not included as it is the stack pointer. */
120
121 *pxTopOfStack = 0x00;
122 pxTopOfStack--;
123 *pxTopOfStack = portINITIAL_PSW;
124 pxTopOfStack--;
125 *pxTopOfStack = ( StackType_t ) pxCode;
126
127 /* When debugging it can be useful if every register is set to a known
128 * value. Otherwise code space can be saved by just setting the registers
129 * that need to be set. */
130 #ifdef USE_FULL_REGISTER_INITIALISATION
131 {
132 pxTopOfStack--;
133 *pxTopOfStack = 0xffffffff; /* r15. */
134 pxTopOfStack--;
135 *pxTopOfStack = 0xeeeeeeee;
136 pxTopOfStack--;
137 *pxTopOfStack = 0xdddddddd;
138 pxTopOfStack--;
139 *pxTopOfStack = 0xcccccccc;
140 pxTopOfStack--;
141 *pxTopOfStack = 0xbbbbbbbb;
142 pxTopOfStack--;
143 *pxTopOfStack = 0xaaaaaaaa;
144 pxTopOfStack--;
145 *pxTopOfStack = 0x99999999;
146 pxTopOfStack--;
147 *pxTopOfStack = 0x88888888;
148 pxTopOfStack--;
149 *pxTopOfStack = 0x77777777;
150 pxTopOfStack--;
151 *pxTopOfStack = 0x66666666;
152 pxTopOfStack--;
153 *pxTopOfStack = 0x55555555;
154 pxTopOfStack--;
155 *pxTopOfStack = 0x44444444;
156 pxTopOfStack--;
157 *pxTopOfStack = 0x33333333;
158 pxTopOfStack--;
159 *pxTopOfStack = 0x22222222;
160 pxTopOfStack--;
161 }
162 #else /* ifdef USE_FULL_REGISTER_INITIALISATION */
163 {
164 pxTopOfStack -= 15;
165 }
166 #endif /* ifdef USE_FULL_REGISTER_INITIALISATION */
167
168 *pxTopOfStack = ( StackType_t ) pvParameters; /* R1 */
169 pxTopOfStack--;
170 *pxTopOfStack = portINITIAL_FPSW;
171 pxTopOfStack--;
172 *pxTopOfStack = 0x11111111; /* Accumulator 1. */
173 pxTopOfStack--;
174 *pxTopOfStack = 0x22222222; /* Accumulator 1. */
175 pxTopOfStack--;
176 *pxTopOfStack = 0x33333333; /* Accumulator 1. */
177 pxTopOfStack--;
178 *pxTopOfStack = 0x44444444; /* Accumulator 0. */
179 pxTopOfStack--;
180 *pxTopOfStack = 0x55555555; /* Accumulator 0. */
181 pxTopOfStack--;
182 *pxTopOfStack = 0x66666666; /* Accumulator 0. */
183
184 #if ( configUSE_TASK_DPFPU_SUPPORT == 1 )
185 {
186 /* The task will start without a DPFPU context. A task that
187 * uses the DPFPU hardware must call vPortTaskUsesDPFPU() before
188 * executing any floating point instructions. */
189 pxTopOfStack--;
190 *pxTopOfStack = portNO_DPFPU_CONTEXT;
191 }
192 #elif ( configUSE_TASK_DPFPU_SUPPORT == 2 )
193 {
194 /* The task will start with a DPFPU context. Leave enough
195 * space for the registers - and ensure they are initialised if desired. */
196 #ifdef USE_FULL_REGISTER_INITIALISATION
197 {
198 pxTopOfStack -= 2;
199 *( double * ) pxTopOfStack = 1515.1515; /* DR15. */
200 pxTopOfStack -= 2;
201 *( double * ) pxTopOfStack = 1414.1414; /* DR14. */
202 pxTopOfStack -= 2;
203 *( double * ) pxTopOfStack = 1313.1313; /* DR13. */
204 pxTopOfStack -= 2;
205 *( double * ) pxTopOfStack = 1212.1212; /* DR12. */
206 pxTopOfStack -= 2;
207 *( double * ) pxTopOfStack = 1111.1111; /* DR11. */
208 pxTopOfStack -= 2;
209 *( double * ) pxTopOfStack = 1010.1010; /* DR10. */
210 pxTopOfStack -= 2;
211 *( double * ) pxTopOfStack = 909.0909; /* DR9. */
212 pxTopOfStack -= 2;
213 *( double * ) pxTopOfStack = 808.0808; /* DR8. */
214 pxTopOfStack -= 2;
215 *( double * ) pxTopOfStack = 707.0707; /* DR7. */
216 pxTopOfStack -= 2;
217 *( double * ) pxTopOfStack = 606.0606; /* DR6. */
218 pxTopOfStack -= 2;
219 *( double * ) pxTopOfStack = 505.0505; /* DR5. */
220 pxTopOfStack -= 2;
221 *( double * ) pxTopOfStack = 404.0404; /* DR4. */
222 pxTopOfStack -= 2;
223 *( double * ) pxTopOfStack = 303.0303; /* DR3. */
224 pxTopOfStack -= 2;
225 *( double * ) pxTopOfStack = 202.0202; /* DR2. */
226 pxTopOfStack -= 2;
227 *( double * ) pxTopOfStack = 101.0101; /* DR1. */
228 pxTopOfStack -= 2;
229 *( double * ) pxTopOfStack = 9876.54321; /* DR0. */
230 }
231 #else /* ifdef USE_FULL_REGISTER_INITIALISATION */
232 {
233 pxTopOfStack -= portDPFPU_DATA_REGISTER_WORDS;
234 memset( pxTopOfStack, 0x00, portDPFPU_DATA_REGISTER_WORDS * sizeof( StackType_t ) );
235 }
236 #endif /* ifdef USE_FULL_REGISTER_INITIALISATION */
237 pxTopOfStack--;
238 *pxTopOfStack = portINITIAL_DECNT; /* DECNT. */
239 pxTopOfStack--;
240 *pxTopOfStack = portINITIAL_DCMR; /* DCMR. */
241 pxTopOfStack--;
242 *pxTopOfStack = portINITIAL_DPSW; /* DPSW. */
243 }
244 #elif ( configUSE_TASK_DPFPU_SUPPORT == 0 )
245 {
246 /* Omit DPFPU support. */
247 }
248 #else /* if ( configUSE_TASK_DPFPU_SUPPORT == 1 ) */
249 {
250 #error Invalid configUSE_TASK_DPFPU_SUPPORT setting - configUSE_TASK_DPFPU_SUPPORT must be set to 0, 1, 2, or left undefined.
251 }
252 #endif /* if ( configUSE_TASK_DPFPU_SUPPORT == 1 ) */
253
254 return pxTopOfStack;
255 }
256 /*-----------------------------------------------------------*/
257
258 #if ( configUSE_TASK_DPFPU_SUPPORT == 1 )
259
vPortTaskUsesDPFPU(void)260 void vPortTaskUsesDPFPU( void )
261 {
262 /* A task is registering the fact that it needs a DPFPU context. Set the
263 * DPFPU flag (which is saved as part of the task context). */
264 ulPortTaskHasDPFPUContext = portHAS_DPFPU_CONTEXT;
265 }
266
267 #endif /* configUSE_TASK_DPFPU_SUPPORT */
268 /*-----------------------------------------------------------*/
269
xPortStartScheduler(void)270 BaseType_t xPortStartScheduler( void )
271 {
272 extern void vApplicationSetupTimerInterrupt( void );
273
274 /* Use pxCurrentTCB just so it does not get optimised away. */
275 if( pxCurrentTCB != NULL )
276 {
277 /* Call an application function to set up the timer that will generate the
278 * tick interrupt. This way the application can decide which peripheral to
279 * use. A demo application is provided to show a suitable example. */
280 vApplicationSetupTimerInterrupt();
281
282 /* Enable the software interrupt. */
283 _IEN( _ICU_SWINT ) = 1;
284
285 /* Ensure the software interrupt is clear. */
286 _IR( _ICU_SWINT ) = 0;
287
288 /* Ensure the software interrupt is set to the kernel priority. */
289 _IPR( _ICU_SWINT ) = configKERNEL_INTERRUPT_PRIORITY;
290
291 /* Start the first task. */
292 prvStartFirstTask();
293 }
294
295 /* Should not get here. */
296 return pdFAIL;
297 }
298 /*-----------------------------------------------------------*/
299
vPortEndScheduler(void)300 void vPortEndScheduler( void )
301 {
302 /* Not implemented in ports where there is nothing to return to.
303 * Artificially force an assert. */
304 configASSERT( pxCurrentTCB == NULL );
305
306 /* The following line is just to prevent the symbol getting optimised away. */
307 ( void ) vTaskSwitchContext();
308 }
309 /*-----------------------------------------------------------*/
310
prvStartFirstTask(void)311 static void prvStartFirstTask( void )
312 {
313 __asm volatile
314 (
315
316 /* When starting the scheduler there is nothing that needs moving to the
317 * interrupt stack because the function is not called from an interrupt.
318 * Just ensure the current stack is the user stack. */
319 "SETPSW U \n" \
320
321
322 /* Obtain the location of the stack associated with which ever task
323 * pxCurrentTCB is currently pointing to. */
324 "MOV.L #_pxCurrentTCB, R15 \n" \
325 "MOV.L [R15], R15 \n" \
326 "MOV.L [R15], R0 \n" \
327
328
329 /* Restore the registers from the stack of the task pointed to by
330 * pxCurrentTCB. */
331
332 #if ( configUSE_TASK_DPFPU_SUPPORT == 1 )
333
334 /* The restored ulPortTaskHasDPFPUContext is to be zero here.
335 * So, it is never necessary to restore the DPFPU context here. */
336 "POP R15 \n" \
337 "MOV.L #_ulPortTaskHasDPFPUContext, R14 \n" \
338 "MOV.L R15, [R14] \n" \
339
340 #elif ( configUSE_TASK_DPFPU_SUPPORT == 2 )
341 /* Restore the DPFPU context. */
342 "DPOPM.L DPSW-DECNT \n" \
343 "DPOPM.D DR0-DR15 \n" \
344
345 #endif /* if ( configUSE_TASK_DPFPU_SUPPORT == 1 ) */
346
347 "POP R15 \n" \
348
349 /* Accumulator low 32 bits. */
350 "MVTACLO R15, A0 \n" \
351 "POP R15 \n" \
352
353 /* Accumulator high 32 bits. */
354 "MVTACHI R15, A0 \n" \
355 "POP R15 \n" \
356
357 /* Accumulator guard. */
358 "MVTACGU R15, A0 \n" \
359 "POP R15 \n" \
360
361 /* Accumulator low 32 bits. */
362 "MVTACLO R15, A1 \n" \
363 "POP R15 \n" \
364
365 /* Accumulator high 32 bits. */
366 "MVTACHI R15, A1 \n" \
367 "POP R15 \n" \
368
369 /* Accumulator guard. */
370 "MVTACGU R15, A1 \n" \
371 "POP R15 \n" \
372
373 /* Floating point status word. */
374 "MVTC R15, FPSW \n" \
375
376 /* R1 to R15 - R0 is not included as it is the SP. */
377 "POPM R1-R15 \n" \
378
379 /* This pops the remaining registers. */
380 "RTE \n" \
381 "NOP \n" \
382 "NOP \n"
383 );
384 }
385 /*-----------------------------------------------------------*/
386
387 #pragma vector = VECT( ICU, SWINT )
vSoftwareInterruptISR(void)388 __interrupt void vSoftwareInterruptISR( void )
389 {
390 __asm volatile
391 (
392 /* Re-enable interrupts. */
393 "SETPSW I \n" \
394
395
396 /* Move the data that was automatically pushed onto the interrupt stack when
397 * the interrupt occurred from the interrupt stack to the user stack.
398 *
399 * R15 is saved before it is clobbered. */
400 "PUSH.L R15 \n" \
401
402 /* Read the user stack pointer. */
403 "MVFC USP, R15 \n" \
404
405 /* Move the address down to the data being moved. */
406 "SUB #12, R15 \n" \
407 "MVTC R15, USP \n" \
408
409 /* Copy the data across, R15, then PC, then PSW. */
410 "MOV.L [ R0 ], [ R15 ] \n" \
411 "MOV.L 4[ R0 ], 4[ R15 ] \n" \
412 "MOV.L 8[ R0 ], 8[ R15 ] \n" \
413
414 /* Move the interrupt stack pointer to its new correct position. */
415 "ADD #12, R0 \n" \
416
417 /* All the rest of the registers are saved directly to the user stack. */
418 "SETPSW U \n" \
419
420 /* Save the rest of the general registers (R15 has been saved already). */
421 "PUSHM R1-R14 \n" \
422
423 /* Save the FPSW and accumulators. */
424 "MVFC FPSW, R15 \n" \
425 "PUSH.L R15 \n" \
426 "MVFACGU #0, A1, R15 \n" \
427 "PUSH.L R15 \n" \
428 "MVFACHI #0, A1, R15 \n" \
429 "PUSH.L R15 \n" \
430 "MVFACLO #0, A1, R15 \n" /* Low order word. */ \
431 "PUSH.L R15 \n" \
432 "MVFACGU #0, A0, R15 \n" \
433 "PUSH.L R15 \n" \
434 "MVFACHI #0, A0, R15 \n" \
435 "PUSH.L R15 \n" \
436 "MVFACLO #0, A0, R15 \n" /* Low order word. */ \
437 "PUSH.L R15 \n" \
438
439 #if ( configUSE_TASK_DPFPU_SUPPORT == 1 )
440
441 /* Does the task have a DPFPU context that needs saving? If
442 * ulPortTaskHasDPFPUContext is 0 then no. */
443 "MOV.L #_ulPortTaskHasDPFPUContext, R15 \n" \
444 "MOV.L [R15], R15 \n" \
445 "CMP #0, R15 \n" \
446
447 /* Save the DPFPU context, if any. */
448 "BEQ.B __lab1 \n" \
449 "DPUSHM.D DR0-DR15 \n" \
450 "DPUSHM.L DPSW-DECNT \n" \
451 "__lab1: \n" \
452
453 /* Save ulPortTaskHasDPFPUContext itself. */
454 "PUSH.L R15 \n" \
455
456 #elif ( configUSE_TASK_DPFPU_SUPPORT == 2 )
457 /* Save the DPFPU context, always. */
458 "DPUSHM.D DR0-DR15 \n" \
459 "DPUSHM.L DPSW-DECNT \n" \
460
461 #endif /* if ( configUSE_TASK_DPFPU_SUPPORT == 1 ) */
462
463
464 /* Save the stack pointer to the TCB. */
465 "MOV.L #_pxCurrentTCB, R15 \n" \
466 "MOV.L [ R15 ], R15 \n" \
467 "MOV.L R0, [ R15 ] \n" \
468
469
470 /* Ensure the interrupt mask is set to the syscall priority while the kernel
471 * structures are being accessed. */
472 "MVTIPL %0 \n" \
473
474 /* Select the next task to run. */
475 "BSR.A _vTaskSwitchContext \n" \
476
477 /* Reset the interrupt mask as no more data structure access is required. */
478 "MVTIPL %1 \n" \
479
480
481 /* Load the stack pointer of the task that is now selected as the Running
482 * state task from its TCB. */
483 "MOV.L #_pxCurrentTCB,R15 \n" \
484 "MOV.L [ R15 ], R15 \n" \
485 "MOV.L [ R15 ], R0 \n" \
486
487
488 /* Restore the context of the new task. The PSW (Program Status Word) and
489 * PC will be popped by the RTE instruction. */
490
491 #if ( configUSE_TASK_DPFPU_SUPPORT == 1 )
492
493 /* Is there a DPFPU context to restore? If the restored
494 * ulPortTaskHasDPFPUContext is zero then no. */
495 "POP R15 \n" \
496 "MOV.L #_ulPortTaskHasDPFPUContext, R14 \n" \
497 "MOV.L R15, [R14] \n" \
498 "CMP #0, R15 \n" \
499
500 /* Restore the DPFPU context, if any. */
501 "BEQ.B __lab2 \n" \
502 "DPOPM.L DPSW-DECNT \n" \
503 "DPOPM.D DR0-DR15 \n" \
504 "__lab2: \n" \
505
506 #elif ( configUSE_TASK_DPFPU_SUPPORT == 2 )
507 /* Restore the DPFPU context, always. */
508 "DPOPM.L DPSW-DECNT \n" \
509 "DPOPM.D DR0-DR15 \n" \
510
511 #endif /* if( configUSE_TASK_DPFPU_SUPPORT == 1 ) */
512
513 "POP R15 \n" \
514
515 /* Accumulator low 32 bits. */
516 "MVTACLO R15, A0 \n" \
517 "POP R15 \n" \
518
519 /* Accumulator high 32 bits. */
520 "MVTACHI R15, A0 \n" \
521 "POP R15 \n" \
522
523 /* Accumulator guard. */
524 "MVTACGU R15, A0 \n" \
525 "POP R15 \n" \
526
527 /* Accumulator low 32 bits. */
528 "MVTACLO R15, A1 \n" \
529 "POP R15 \n" \
530
531 /* Accumulator high 32 bits. */
532 "MVTACHI R15, A1 \n" \
533 "POP R15 \n" \
534
535 /* Accumulator guard. */
536 "MVTACGU R15, A1 \n" \
537 "POP R15 \n" \
538 "MVTC R15, FPSW \n" \
539 "POPM R1-R15 \n" \
540 "RTE \n" \
541 "NOP \n" \
542 "NOP "
543 portCDT_NO_PARSE( ::) "i" ( configMAX_SYSCALL_INTERRUPT_PRIORITY ), "i" ( configKERNEL_INTERRUPT_PRIORITY )
544 );
545 }
546 /*-----------------------------------------------------------*/
547
548 #pragma vector = _VECT( configTICK_VECTOR )
vTickISR(void)549 __interrupt void vTickISR( void )
550 {
551 /* Re-enable interrupts. */
552 __enable_interrupt();
553
554 /* Increment the tick, and perform any processing the new tick value
555 * necessitates. Ensure IPL is at the max syscall value first. */
556 __set_interrupt_level( configMAX_SYSCALL_INTERRUPT_PRIORITY );
557 {
558 if( xTaskIncrementTick() != pdFALSE )
559 {
560 taskYIELD();
561 }
562 }
563 __set_interrupt_level( configKERNEL_INTERRUPT_PRIORITY );
564 }
565 /*-----------------------------------------------------------*/
566
