/* * FreeRTOS Kernel * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved. * * SPDX-License-Identifier: MIT * * Permission is hereby granted, free of charge, to any person obtaining a copy of * this software and associated documentation files (the "Software"), to deal in * the Software without restriction, including without limitation the rights to * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of * the Software, and to permit persons to whom the Software is furnished to do so, * subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. * * https://www.FreeRTOS.org * https://github.com/FreeRTOS * */ #include "FreeRTOS.h" #include "task.h" /*----------------------------------------------------------- * Implementation of functions defined in portable.h for the 16FX port. *----------------------------------------------------------*/ /* * Get current value of DPR and ADB registers */ StackType_t xGet_DPR_ADB_bank( void ); /* * Get current value of DTB and PCB registers */ StackType_t xGet_DTB_PCB_bank( void ); /* * Sets up the periodic ISR used for the RTOS tick. This uses RLT0, but * can be done using any given RLT. */ static void prvSetupRLT0Interrupt( void ); /*-----------------------------------------------------------*/ /* * We require the address of the pxCurrentTCB variable, but don't want to know * any details of its type. */ typedef void TCB_t; extern volatile TCB_t * volatile pxCurrentTCB; /*-----------------------------------------------------------*/ /* * Macro to save a task context to the task stack. This macro copies the * saved context (AH:AL, DPR:ADB, DTB:PCB , PC and PS) from the system * stack to task stack pointed by user stack pointer ( USP for SMALL and * MEDIUM memory model amd USB:USP for COMPACT and LARGE memory model ), * then it pushes the general purpose registers RW0-RW7 on to the task * stack. Finally the resultant stack pointer value is saved into the * task control block so it can be retrieved the next time the task * executes. */ #if ( ( configMEMMODEL == portSMALL ) || ( configMEMMODEL == portMEDIUM ) ) #define portSAVE_CONTEXT() \ { __asm( " POPW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " PUSHW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " POPW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " PUSHW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " POPW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " PUSHW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " POPW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " PUSHW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " POPW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " PUSHW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " POPW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " PUSHW A " ); \ __asm( " PUSHW (RW0,RW1,RW2,RW3,RW4,RW5,RW6,RW7) " ); \ __asm( " MOVW A, _pxCurrentTCB " ); \ __asm( " MOVW A, SP " ); \ __asm( " SWAPW " ); \ __asm( " MOVW @AL, AH " ); \ __asm( " OR CCR,#H'20 " ); \ } /* * Macro to restore a task context from the task stack. This is * effectively the reverse of SAVE_CONTEXT(). First the stack pointer * value (USP for SMALL and MEDIUM memory model amd USB:USP for COMPACT * and LARGE memory model ) is loaded from the task control block. Next the * value of all the general purpose registers RW0-RW7 is retrieved. * Finally it copies of the context ( AH:AL, DPR:ADB, DTB:PCB, PC and PS) * of the task to be executed upon RETI from user stack to system stack. */ #define portRESTORE_CONTEXT() \ { __asm( " MOVW A, _pxCurrentTCB " ); \ __asm( " MOVW A, @A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " MOVW SP, A " ); \ __asm( " POPW (RW0,RW1,RW2,RW3,RW4,RW5,RW6,RW7) " ); \ __asm( " POPW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " PUSHW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " POPW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " PUSHW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " POPW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " PUSHW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " POPW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " PUSHW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " POPW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " PUSHW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " POPW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " PUSHW A " ); \ } #elif ( ( configMEMMODEL == portCOMPACT ) || ( configMEMMODEL == portLARGE ) ) #define portSAVE_CONTEXT() \ { __asm( " POPW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " PUSHW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " POPW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " PUSHW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " POPW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " PUSHW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " POPW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " PUSHW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " POPW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " PUSHW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " POPW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " PUSHW A " ); \ __asm( " PUSHW (RW0,RW1,RW2,RW3,RW4,RW5,RW6,RW7) " ); \ __asm( " MOVL A, _pxCurrentTCB " ); \ __asm( " MOVL RL2, A " ); \ __asm( " MOVW A, SP " ); \ __asm( " MOVW @RL2+0, A " ); \ __asm( " MOV A, USB " ); \ __asm( " MOV @RL2+2, A " ); \ } #define portRESTORE_CONTEXT() \ { __asm( " MOVL A, _pxCurrentTCB " ); \ __asm( " MOVL RL2, A " ); \ __asm( " MOVW A, @RL2+0 " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " MOVW SP, A " ); \ __asm( " MOV A, @RL2+2 " ); \ __asm( " MOV USB, A " ); \ __asm( " POPW (RW0,RW1,RW2,RW3,RW4,RW5,RW6,RW7) " ); \ __asm( " POPW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " PUSHW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " POPW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " PUSHW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " POPW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " PUSHW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " POPW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " PUSHW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " POPW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " PUSHW A " ); \ __asm( " AND CCR,#H'DF " ); \ __asm( " POPW A " ); \ __asm( " OR CCR,#H'20 " ); \ __asm( " PUSHW A " ); \ } #endif /* if ( ( configMEMMODEL == portSMALL ) || ( configMEMMODEL == portMEDIUM ) ) */ /*-----------------------------------------------------------*/ /* * Functions for obtaining the current value of DPR:ADB, DTB:PCB bank registers */ #pragma asm .GLOBAL _xGet_DPR_ADB_bank .GLOBAL _xGet_DTB_PCB_bank .SECTION CODE, CODE, ALIGN=1 _xGet_DPR_ADB_bank: MOV A, DPR SWAP MOV A, ADB ORW A #if configMEMMODEL == portMEDIUM || configMEMMODEL == portLARGE RETP #elif configMEMMODEL == portSMALL || configMEMMODEL == portCOMPACT RET #endif _xGet_DTB_PCB_bank: MOV A, DTB SWAP MOV A, PCB ORW A #if configMEMMODEL == portMEDIUM || configMEMMODEL == portLARGE RETP #elif configMEMMODEL == portSMALL || configMEMMODEL == portCOMPACT RET #endif #pragma endasm /*-----------------------------------------------------------*/ /* * Initialise the stack of a task to look exactly as if a call to * portSAVE_CONTEXT had been called. * * See the header file portable.h. */ StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack, TaskFunction_t pxCode, void * pvParameters ) { /* Place a few bytes of known values on the bottom of the stack. * This is just useful for debugging. */ *pxTopOfStack = 0x1111; pxTopOfStack--; *pxTopOfStack = 0x2222; pxTopOfStack--; *pxTopOfStack = 0x3333; pxTopOfStack--; /* Once the task is called the task would push the pointer to the * parameter onto the stack. Hence here the pointer would be copied to the stack * first. When using the COMPACT or LARGE memory model the pointer would be 24 * bits, and when using the SMALL or MEDIUM memory model the pointer would be 16 * bits. */ #if ( ( configMEMMODEL == portCOMPACT ) || ( configMEMMODEL == portLARGE ) ) { *pxTopOfStack = ( StackType_t ) ( ( uint32_t ) ( pvParameters ) >> 16 ); pxTopOfStack--; } #endif *pxTopOfStack = ( StackType_t ) ( pvParameters ); pxTopOfStack--; /* This is redundant push to the stack. This is required in order to introduce * an offset so that the task accesses a parameter correctly that is passed on to * the task stack. */ #if ( ( configMEMMODEL == portMEDIUM ) || ( configMEMMODEL == portLARGE ) ) { *pxTopOfStack = ( xGet_DTB_PCB_bank() & 0xff00 ) | ( ( ( int32_t ) ( pxCode ) >> 16 ) & 0xff ); pxTopOfStack--; } #endif /* This is redundant push to the stack. This is required in order to introduce * an offset so the task correctly accesses the parameter passed on the task stack. */ *pxTopOfStack = ( StackType_t ) ( pxCode ); pxTopOfStack--; /* PS - User Mode, ILM=7, RB=0, Interrupts enabled,USP */ *pxTopOfStack = 0xE0C0; pxTopOfStack--; /* PC */ *pxTopOfStack = ( StackType_t ) ( pxCode ); pxTopOfStack--; /* DTB | PCB */ #if configMEMMODEL == portSMALL || configMEMMODEL == portCOMPACT { *pxTopOfStack = xGet_DTB_PCB_bank(); pxTopOfStack--; } #endif /* DTB | PCB, in case of MEDIUM and LARGE memory models, PCB would be used * along with PC to indicate the start address of the function. */ #if ( ( configMEMMODEL == portMEDIUM ) || ( configMEMMODEL == portLARGE ) ) { *pxTopOfStack = ( xGet_DTB_PCB_bank() & 0xff00 ) | ( ( ( int32_t ) ( pxCode ) >> 16 ) & 0xff ); pxTopOfStack--; } #endif /* DPR | ADB */ *pxTopOfStack = xGet_DPR_ADB_bank(); pxTopOfStack--; /* AL */ *pxTopOfStack = ( StackType_t ) 0x9999; pxTopOfStack--; /* AH */ *pxTopOfStack = ( StackType_t ) 0xAAAA; pxTopOfStack--; /* Next the general purpose registers. */ *pxTopOfStack = ( StackType_t ) 0x7777; /* RW7 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x6666; /* RW6 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x5555; /* RW5 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x4444; /* RW4 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x3333; /* RW3 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x2222; /* RW2 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x1111; /* RW1 */ pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0x8888; /* RW0 */ return pxTopOfStack; } /*-----------------------------------------------------------*/ static void prvSetupRLT0Interrupt( void ) { /* The peripheral clock divided by 16 is used by the timer. */ const uint16_t usReloadValue = ( uint16_t ) ( ( ( configCLKP1_CLOCK_HZ / configTICK_RATE_HZ ) / 16UL ) - 1UL ); /* set reload value = 34999+1, TICK Interrupt after 10 ms @ 56MHz of CLKP1 */ TMRLR0 = usReloadValue; /* prescaler 1:16, reload, interrupt enable, count enable, trigger */ TMCSR0 = 0x041B; } /*-----------------------------------------------------------*/ BaseType_t xPortStartScheduler( void ) { /* Setup the hardware to generate the tick. */ prvSetupRLT0Interrupt(); /* Restore the context of the first task that is going to run. */ portRESTORE_CONTEXT(); /* Simulate a function call end as generated by the compiler. We will now * jump to the start of the task the context of which we have just restored. */ __asm( " reti " ); /* Should not get here. */ return pdTRUE; } /*-----------------------------------------------------------*/ void vPortEndScheduler( void ) { /* Not implemented - unlikely to ever be required as there is nothing to * return to. */ } /*-----------------------------------------------------------*/ /* * The interrupt service routine used depends on whether the pre-emptive * scheduler is being used or not. */ #if configUSE_PREEMPTION == 1 /* * Tick ISR for preemptive scheduler. We can use a __nosavereg attribute * as the context is to be saved by the portSAVE_CONTEXT() macro, not the * compiler generated code. The tick count is incremented after the context * is saved. */ __nosavereg __interrupt void prvRLT0_TICKISR( void ) { /* Disable interrupts so that portSAVE_CONTEXT() is not interrupted */ __DI(); /* Save the context of the interrupted task. */ portSAVE_CONTEXT(); /* Enable interrupts */ __EI(); /* Clear RLT0 interrupt flag */ TMCSR0_UF = 0; /* Increment the tick count then switch to the highest priority task * that is ready to run. */ if( xTaskIncrementTick() != pdFALSE ) { vTaskSwitchContext(); } /* Disable interrupts so that portRESTORE_CONTEXT() is not interrupted */ __DI(); /* Restore the context of the new task. */ portRESTORE_CONTEXT(); /* Enable interrupts */ __EI(); } #else /* if configUSE_PREEMPTION == 1 */ /* * Tick ISR for the cooperative scheduler. All this does is increment the * tick count. We don't need to switch context, this can only be done by * manual calls to taskYIELD(); */ __interrupt void prvRLT0_TICKISR( void ) { /* Clear RLT0 interrupt flag */ TMCSR0_UF = 0; xTaskIncrementTick(); } #endif /* if configUSE_PREEMPTION == 1 */ /*-----------------------------------------------------------*/ /* * Manual context switch. We can use a __nosavereg attribute as the context * is to be saved by the portSAVE_CONTEXT() macro, not the compiler generated * code. */ __nosavereg __interrupt void vPortYield( void ) { /* Save the context of the interrupted task. */ portSAVE_CONTEXT(); /* Switch to the highest priority task that is ready to run. */ vTaskSwitchContext(); /* Restore the context of the new task. */ portRESTORE_CONTEXT(); } /*-----------------------------------------------------------*/ __nosavereg __interrupt void vPortYieldDelayed( void ) { /* Disable interrupts so that portSAVE_CONTEXT() is not interrupted */ __DI(); /* Save the context of the interrupted task. */ portSAVE_CONTEXT(); /* Enable interrupts */ __EI(); /* Clear delayed interrupt flag */ __asm( " CLRB 03A4H:0 " ); /* Switch to the highest priority task that is ready to run. */ vTaskSwitchContext(); /* Disable interrupts so that portSAVE_CONTEXT() is not interrupted */ __DI(); /* Restore the context of the new task. */ portRESTORE_CONTEXT(); /* Enable interrupts */ __EI(); } /*-----------------------------------------------------------*/