1 /*
2 * FreeRTOS Kernel V10.6.2
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 #include "FreeRTOS.h"
30 #include "task.h"
31
32 /*-----------------------------------------------------------
33 * Implementation of functions defined in portable.h for the 16FX port.
34 *----------------------------------------------------------*/
35
36 /*
37 * Get current value of DPR and ADB registers
38 */
39 StackType_t xGet_DPR_ADB_bank( void );
40
41 /*
42 * Get current value of DTB and PCB registers
43 */
44 StackType_t xGet_DTB_PCB_bank( void );
45
46 /*
47 * Sets up the periodic ISR used for the RTOS tick. This uses RLT0, but
48 * can be done using any given RLT.
49 */
50 static void prvSetupRLT0Interrupt( void );
51
52 /*-----------------------------------------------------------*/
53
54 /*
55 * We require the address of the pxCurrentTCB variable, but don't want to know
56 * any details of its type.
57 */
58 typedef void TCB_t;
59 extern volatile TCB_t * volatile pxCurrentTCB;
60
61 /*-----------------------------------------------------------*/
62
63 /*
64 * Macro to save a task context to the task stack. This macro copies the
65 * saved context (AH:AL, DPR:ADB, DTB:PCB , PC and PS) from the system
66 * stack to task stack pointed by user stack pointer ( USP for SMALL and
67 * MEDIUM memory model amd USB:USP for COMPACT and LARGE memory model ),
68 * then it pushes the general purpose registers RW0-RW7 on to the task
69 * stack. Finally the resultant stack pointer value is saved into the
70 * task control block so it can be retrieved the next time the task
71 * executes.
72 */
73 #if( ( configMEMMODEL == portSMALL ) || ( configMEMMODEL == portMEDIUM ) )
74
75 #define portSAVE_CONTEXT() \
76 { __asm(" POPW A "); \
77 __asm(" AND CCR,#H'DF "); \
78 __asm(" PUSHW A "); \
79 __asm(" OR CCR,#H'20 "); \
80 __asm(" POPW A "); \
81 __asm(" AND CCR,#H'DF "); \
82 __asm(" PUSHW A "); \
83 __asm(" OR CCR,#H'20 "); \
84 __asm(" POPW A "); \
85 __asm(" AND CCR,#H'DF "); \
86 __asm(" PUSHW A "); \
87 __asm(" OR CCR,#H'20 "); \
88 __asm(" POPW A "); \
89 __asm(" AND CCR,#H'DF "); \
90 __asm(" PUSHW A "); \
91 __asm(" OR CCR,#H'20 "); \
92 __asm(" POPW A "); \
93 __asm(" AND CCR,#H'DF "); \
94 __asm(" PUSHW A "); \
95 __asm(" OR CCR,#H'20 "); \
96 __asm(" POPW A "); \
97 __asm(" AND CCR,#H'DF "); \
98 __asm(" PUSHW A "); \
99 __asm(" PUSHW (RW0,RW1,RW2,RW3,RW4,RW5,RW6,RW7) "); \
100 __asm(" MOVW A, _pxCurrentTCB "); \
101 __asm(" MOVW A, SP "); \
102 __asm(" SWAPW "); \
103 __asm(" MOVW @AL, AH "); \
104 __asm(" OR CCR,#H'20 "); \
105 }
106
107 /*
108 * Macro to restore a task context from the task stack. This is effecti-
109 * vely the reverse of SAVE_CONTEXT(). First the stack pointer value
110 * (USP for SMALL and MEDIUM memory model amd USB:USP for COMPACT and
111 * LARGE memory model ) is loaded from the task control block. Next the
112 * value of all the general purpose registers RW0-RW7 is retrieved. Fina-
113 * lly it copies of the context ( AH:AL, DPR:ADB, DTB:PCB, PC and PS) of
114 * the task to be executed upon RETI from user stack to system stack.
115 */
116
117 #define portRESTORE_CONTEXT() \
118 { __asm(" MOVW A, _pxCurrentTCB "); \
119 __asm(" MOVW A, @A "); \
120 __asm(" AND CCR,#H'DF "); \
121 __asm(" MOVW SP, A "); \
122 __asm(" POPW (RW0,RW1,RW2,RW3,RW4,RW5,RW6,RW7) "); \
123 __asm(" POPW A "); \
124 __asm(" OR CCR,#H'20 "); \
125 __asm(" PUSHW A "); \
126 __asm(" AND CCR,#H'DF "); \
127 __asm(" POPW A "); \
128 __asm(" OR CCR,#H'20 "); \
129 __asm(" PUSHW A "); \
130 __asm(" AND CCR,#H'DF "); \
131 __asm(" POPW A "); \
132 __asm(" OR CCR,#H'20 "); \
133 __asm(" PUSHW A "); \
134 __asm(" AND CCR,#H'DF "); \
135 __asm(" POPW A "); \
136 __asm(" OR CCR,#H'20 "); \
137 __asm(" PUSHW A "); \
138 __asm(" AND CCR,#H'DF "); \
139 __asm(" POPW A "); \
140 __asm(" OR CCR,#H'20 "); \
141 __asm(" PUSHW A "); \
142 __asm(" AND CCR,#H'DF "); \
143 __asm(" POPW A "); \
144 __asm(" OR CCR,#H'20 "); \
145 __asm(" PUSHW A "); \
146 }
147
148 #elif( ( configMEMMODEL == portCOMPACT ) || ( configMEMMODEL == portLARGE ) )
149
150 #define portSAVE_CONTEXT() \
151 { __asm(" POPW A "); \
152 __asm(" AND CCR,#H'DF "); \
153 __asm(" PUSHW A "); \
154 __asm(" OR CCR,#H'20 "); \
155 __asm(" POPW A "); \
156 __asm(" AND CCR,#H'DF "); \
157 __asm(" PUSHW A "); \
158 __asm(" OR CCR,#H'20 "); \
159 __asm(" POPW A "); \
160 __asm(" AND CCR,#H'DF "); \
161 __asm(" PUSHW A "); \
162 __asm(" OR CCR,#H'20 "); \
163 __asm(" POPW A "); \
164 __asm(" AND CCR,#H'DF "); \
165 __asm(" PUSHW A "); \
166 __asm(" OR CCR,#H'20 "); \
167 __asm(" POPW A "); \
168 __asm(" AND CCR,#H'DF "); \
169 __asm(" PUSHW A "); \
170 __asm(" OR CCR,#H'20 "); \
171 __asm(" POPW A "); \
172 __asm(" AND CCR,#H'DF "); \
173 __asm(" PUSHW A "); \
174 __asm(" PUSHW (RW0,RW1,RW2,RW3,RW4,RW5,RW6,RW7) "); \
175 __asm(" MOVL A, _pxCurrentTCB "); \
176 __asm(" MOVL RL2, A "); \
177 __asm(" MOVW A, SP "); \
178 __asm(" MOVW @RL2+0, A "); \
179 __asm(" MOV A, USB "); \
180 __asm(" MOV @RL2+2, A "); \
181 }
182
183 #define portRESTORE_CONTEXT() \
184 { __asm(" MOVL A, _pxCurrentTCB "); \
185 __asm(" MOVL RL2, A "); \
186 __asm(" MOVW A, @RL2+0 "); \
187 __asm(" AND CCR,#H'DF "); \
188 __asm(" MOVW SP, A "); \
189 __asm(" MOV A, @RL2+2 "); \
190 __asm(" MOV USB, A "); \
191 __asm(" POPW (RW0,RW1,RW2,RW3,RW4,RW5,RW6,RW7) "); \
192 __asm(" POPW A "); \
193 __asm(" OR CCR,#H'20 "); \
194 __asm(" PUSHW A "); \
195 __asm(" AND CCR,#H'DF "); \
196 __asm(" POPW A "); \
197 __asm(" OR CCR,#H'20 "); \
198 __asm(" PUSHW A "); \
199 __asm(" AND CCR,#H'DF "); \
200 __asm(" POPW A "); \
201 __asm(" OR CCR,#H'20 "); \
202 __asm(" PUSHW A "); \
203 __asm(" AND CCR,#H'DF "); \
204 __asm(" POPW A "); \
205 __asm(" OR CCR,#H'20 "); \
206 __asm(" PUSHW A "); \
207 __asm(" AND CCR,#H'DF "); \
208 __asm(" POPW A "); \
209 __asm(" OR CCR,#H'20 "); \
210 __asm(" PUSHW A "); \
211 __asm(" AND CCR,#H'DF "); \
212 __asm(" POPW A "); \
213 __asm(" OR CCR,#H'20 "); \
214 __asm(" PUSHW A "); \
215 }
216 #endif
217
218 /*-----------------------------------------------------------*/
219
220 /*
221 * Functions for obtaining the current value of DPR:ADB, DTB:PCB bank registers
222 */
223
224 #pragma asm
225
226 .GLOBAL _xGet_DPR_ADB_bank
227 .GLOBAL _xGet_DTB_PCB_bank
228 .SECTION CODE, CODE, ALIGN=1
229
230 _xGet_DPR_ADB_bank:
231
232 MOV A, DPR
233 SWAP
234 MOV A, ADB
235 ORW A
236 #if configMEMMODEL == portMEDIUM || configMEMMODEL == portLARGE
237 RETP
238 #elif configMEMMODEL == portSMALL || configMEMMODEL == portCOMPACT
239 RET
240 #endif
241
242
243 _xGet_DTB_PCB_bank:
244
245 MOV A, DTB
246 SWAP
247 MOV A, PCB
248 ORW A
249 #if configMEMMODEL == portMEDIUM || configMEMMODEL == portLARGE
250 RETP
251 #elif configMEMMODEL == portSMALL || configMEMMODEL == portCOMPACT
252 RET
253 #endif
254
255 #pragma endasm
256 /*-----------------------------------------------------------*/
257
258 /*
259 * Initialise the stack of a task to look exactly as if a call to
260 * portSAVE_CONTEXT had been called.
261 *
262 * See the header file portable.h.
263 */
264 StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )
265 {
266 /* Place a few bytes of known values on the bottom of the stack.
267 This is just useful for debugging. */
268 *pxTopOfStack = 0x1111;
269 pxTopOfStack--;
270 *pxTopOfStack = 0x2222;
271 pxTopOfStack--;
272 *pxTopOfStack = 0x3333;
273 pxTopOfStack--;
274
275 /* Once the task is called the task would push the pointer to the
276 parameter onto the stack. Hence here the pointer would be copied to the stack
277 first. When using the COMPACT or LARGE memory model the pointer would be 24
278 bits, and when using the SMALL or MEDIUM memory model the pointer would be 16
279 bits. */
280 #if( ( configMEMMODEL == portCOMPACT ) || ( configMEMMODEL == portLARGE ) )
281 {
282 *pxTopOfStack = ( StackType_t ) ( ( uint32_t ) ( pvParameters ) >> 16 );
283 pxTopOfStack--;
284 }
285 #endif
286
287 *pxTopOfStack = ( StackType_t ) ( pvParameters );
288 pxTopOfStack--;
289
290 /* This is redundant push to the stack. This is required in order to introduce
291 an offset so that the task accesses a parameter correctly that is passed on to
292 the task stack. */
293 #if( ( configMEMMODEL == portMEDIUM ) || ( configMEMMODEL == portLARGE ) )
294 {
295 *pxTopOfStack = ( xGet_DTB_PCB_bank() & 0xff00 ) | ( ( ( int32_t ) ( pxCode ) >> 16 ) & 0xff );
296 pxTopOfStack--;
297 }
298 #endif
299
300 /* This is redundant push to the stack. This is required in order to introduce
301 an offset so the task correctly accesses the parameter passed on the task stack. */
302 *pxTopOfStack = ( StackType_t ) ( pxCode );
303 pxTopOfStack--;
304
305 /* PS - User Mode, ILM=7, RB=0, Interrupts enabled,USP */
306 *pxTopOfStack = 0xE0C0;
307 pxTopOfStack--;
308
309 /* PC */
310 *pxTopOfStack = ( StackType_t ) ( pxCode );
311 pxTopOfStack--;
312
313 /* DTB | PCB */
314 #if configMEMMODEL == portSMALL || configMEMMODEL == portCOMPACT
315 {
316 *pxTopOfStack = xGet_DTB_PCB_bank();
317 pxTopOfStack--;
318 }
319 #endif
320
321 /* DTB | PCB, in case of MEDIUM and LARGE memory models, PCB would be used
322 along with PC to indicate the start address of the function. */
323 #if( ( configMEMMODEL == portMEDIUM ) || ( configMEMMODEL == portLARGE ) )
324 {
325 *pxTopOfStack = ( xGet_DTB_PCB_bank() & 0xff00 ) | ( ( ( int32_t ) ( pxCode ) >> 16 ) & 0xff );
326 pxTopOfStack--;
327 }
328 #endif
329
330 /* DPR | ADB */
331 *pxTopOfStack = xGet_DPR_ADB_bank();
332 pxTopOfStack--;
333
334 /* AL */
335 *pxTopOfStack = ( StackType_t ) 0x9999;
336 pxTopOfStack--;
337
338 /* AH */
339 *pxTopOfStack = ( StackType_t ) 0xAAAA;
340 pxTopOfStack--;
341
342 /* Next the general purpose registers. */
343 *pxTopOfStack = ( StackType_t ) 0x7777; /* RW7 */
344 pxTopOfStack--;
345 *pxTopOfStack = ( StackType_t ) 0x6666; /* RW6 */
346 pxTopOfStack--;
347 *pxTopOfStack = ( StackType_t ) 0x5555; /* RW5 */
348 pxTopOfStack--;
349 *pxTopOfStack = ( StackType_t ) 0x4444; /* RW4 */
350 pxTopOfStack--;
351 *pxTopOfStack = ( StackType_t ) 0x3333; /* RW3 */
352 pxTopOfStack--;
353 *pxTopOfStack = ( StackType_t ) 0x2222; /* RW2 */
354 pxTopOfStack--;
355 *pxTopOfStack = ( StackType_t ) 0x1111; /* RW1 */
356 pxTopOfStack--;
357 *pxTopOfStack = ( StackType_t ) 0x8888; /* RW0 */
358
359 return pxTopOfStack;
360 }
361 /*-----------------------------------------------------------*/
362
prvSetupRLT0Interrupt(void)363 static void prvSetupRLT0Interrupt( void )
364 {
365 /* The peripheral clock divided by 16 is used by the timer. */
366 const uint16_t usReloadValue = ( uint16_t ) ( ( ( configCLKP1_CLOCK_HZ / configTICK_RATE_HZ ) / 16UL ) - 1UL );
367
368 /* set reload value = 34999+1, TICK Interrupt after 10 ms @ 56MHz of CLKP1 */
369 TMRLR0 = usReloadValue;
370
371 /* prescaler 1:16, reload, interrupt enable, count enable, trigger */
372 TMCSR0 = 0x041B;
373 }
374 /*-----------------------------------------------------------*/
375
xPortStartScheduler(void)376 BaseType_t xPortStartScheduler( void )
377 {
378 /* Setup the hardware to generate the tick. */
379 prvSetupRLT0Interrupt();
380
381 /* Restore the context of the first task that is going to run. */
382 portRESTORE_CONTEXT();
383
384 /* Simulate a function call end as generated by the compiler. We will now
385 jump to the start of the task the context of which we have just restored. */
386 __asm(" reti ");
387
388
389 /* Should not get here. */
390 return pdTRUE;
391 }
392 /*-----------------------------------------------------------*/
393
vPortEndScheduler(void)394 void vPortEndScheduler( void )
395 {
396 /* Not implemented - unlikely to ever be required as there is nothing to
397 return to. */
398 }
399
400 /*-----------------------------------------------------------*/
401
402 /*
403 * The interrupt service routine used depends on whether the pre-emptive
404 * scheduler is being used or not.
405 */
406
407 #if configUSE_PREEMPTION == 1
408
409 /*
410 * Tick ISR for preemptive scheduler. We can use a __nosavereg attribute
411 * as the context is to be saved by the portSAVE_CONTEXT() macro, not the
412 * compiler generated code. The tick count is incremented after the context
413 * is saved.
414 */
prvRLT0_TICKISR(void)415 __nosavereg __interrupt void prvRLT0_TICKISR( void )
416 {
417 /* Disable interrupts so that portSAVE_CONTEXT() is not interrupted */
418 __DI();
419
420 /* Save the context of the interrupted task. */
421 portSAVE_CONTEXT();
422
423 /* Enable interrupts */
424 __EI();
425
426 /* Clear RLT0 interrupt flag */
427 TMCSR0_UF = 0;
428
429 /* Increment the tick count then switch to the highest priority task
430 that is ready to run. */
431 if( xTaskIncrementTick() != pdFALSE )
432 {
433 vTaskSwitchContext();
434 }
435
436 /* Disable interrupts so that portRESTORE_CONTEXT() is not interrupted */
437 __DI();
438
439 /* Restore the context of the new task. */
440 portRESTORE_CONTEXT();
441
442 /* Enable interrupts */
443 __EI();
444 }
445
446 #else
447
448 /*
449 * Tick ISR for the cooperative scheduler. All this does is increment the
450 * tick count. We don't need to switch context, this can only be done by
451 * manual calls to taskYIELD();
452 */
prvRLT0_TICKISR(void)453 __interrupt void prvRLT0_TICKISR( void )
454 {
455 /* Clear RLT0 interrupt flag */
456 TMCSR0_UF = 0;
457
458 xTaskIncrementTick();
459 }
460
461 #endif
462
463 /*-----------------------------------------------------------*/
464
465 /*
466 * Manual context switch. We can use a __nosavereg attribute as the context
467 * is to be saved by the portSAVE_CONTEXT() macro, not the compiler generated
468 * code.
469 */
vPortYield(void)470 __nosavereg __interrupt void vPortYield( void )
471 {
472 /* Save the context of the interrupted task. */
473 portSAVE_CONTEXT();
474
475 /* Switch to the highest priority task that is ready to run. */
476 vTaskSwitchContext();
477
478 /* Restore the context of the new task. */
479 portRESTORE_CONTEXT();
480 }
481 /*-----------------------------------------------------------*/
482
vPortYieldDelayed(void)483 __nosavereg __interrupt void vPortYieldDelayed( void )
484 {
485 /* Disable interrupts so that portSAVE_CONTEXT() is not interrupted */
486 __DI();
487
488 /* Save the context of the interrupted task. */
489 portSAVE_CONTEXT();
490
491 /* Enable interrupts */
492 __EI();
493
494 /* Clear delayed interrupt flag */
495 __asm (" CLRB 03A4H:0 ");
496
497 /* Switch to the highest priority task that is ready to run. */
498 vTaskSwitchContext();
499
500 /* Disable interrupts so that portSAVE_CONTEXT() is not interrupted */
501 __DI();
502
503 /* Restore the context of the new task. */
504 portRESTORE_CONTEXT();
505
506 /* Enable interrupts */
507 __EI();
508 }
509 /*-----------------------------------------------------------*/
510
