| /* |
| * FreeRTOS Kernel <DEVELOPMENT BRANCH> |
| * 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 |
| * |
| */ |
| |
| /* Scheduler includes. */ |
| #include "FreeRTOS.h" |
| #include "task.h" |
| |
| /* Hardware includes. */ |
| #include "msp430.h" |
| |
| /*----------------------------------------------------------- |
| * Implementation of functions defined in portable.h for the MSP430X port. |
| *----------------------------------------------------------*/ |
| |
| /* Constants required for hardware setup. The tick ISR runs off the ACLK, |
| * not the MCLK. */ |
| #define portACLK_FREQUENCY_HZ ( ( TickType_t ) 32768 ) |
| #define portINITIAL_CRITICAL_NESTING ( ( uint16_t ) 10 ) |
| #define portFLAGS_INT_ENABLED ( ( StackType_t ) 0x08 ) |
| |
| /* 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; |
| |
| /* Each task maintains a count of the critical section nesting depth. Each |
| * time a critical section is entered the count is incremented. Each time a |
| * critical section is exited the count is decremented - with interrupts only |
| * being re-enabled if the count is zero. |
| * |
| * usCriticalNesting will get set to zero when the scheduler starts, but must |
| * not be initialised to zero as this will cause problems during the startup |
| * sequence. */ |
| volatile uint16_t usCriticalNesting = portINITIAL_CRITICAL_NESTING; |
| /*-----------------------------------------------------------*/ |
| |
| |
| /* |
| * Sets up the periodic ISR used for the RTOS tick. This uses timer 0, but |
| * could have alternatively used the watchdog timer or timer 1. |
| */ |
| void vPortSetupTimerInterrupt( void ); |
| /*-----------------------------------------------------------*/ |
| |
| /* |
| * 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 ) |
| { |
| uint16_t * pusTopOfStack; |
| uint32_t * pulTopOfStack; |
| |
| /* |
| * Place a few bytes of known values on the bottom of the stack. |
| * This is just useful for debugging and can be included if required. |
| * |
| * pxTopOfStack = ( StackType_t ) 0x1111; |
| * pxTopOfStack--; |
| * pxTopOfStack = ( StackType_t ) 0x2222; |
| * pxTopOfStack--; |
| * pxTopOfStack = ( StackType_t ) 0x3333; |
| */ |
| |
| /* StackType_t is either 16 bits or 32 bits depending on the data model. |
| * Some stacked items do not change size depending on the data model so have |
| * to be explicitly cast to the correct size so this function will work |
| * whichever data model is being used. */ |
| if( sizeof( StackType_t ) == sizeof( uint16_t ) ) |
| { |
| /* Make room for a 20 bit value stored as a 32 bit value. */ |
| pusTopOfStack = ( uint16_t * ) pxTopOfStack; |
| pusTopOfStack--; |
| pulTopOfStack = ( uint32_t * ) pusTopOfStack; |
| } |
| else |
| { |
| pulTopOfStack = ( uint32_t * ) pxTopOfStack; |
| } |
| |
| *pulTopOfStack = ( uint32_t ) pxCode; |
| |
| pusTopOfStack = ( uint16_t * ) pulTopOfStack; |
| pusTopOfStack--; |
| *pusTopOfStack = portFLAGS_INT_ENABLED; |
| pusTopOfStack -= ( sizeof( StackType_t ) / 2 ); |
| |
| /* From here on the size of stacked items depends on the memory model. */ |
| pxTopOfStack = ( StackType_t * ) pusTopOfStack; |
| |
| /* Next the general purpose registers. */ |
| #ifdef PRELOAD_REGISTER_VALUES |
| *pxTopOfStack = ( StackType_t ) 0xffff; |
| pxTopOfStack--; |
| *pxTopOfStack = ( StackType_t ) 0xeeee; |
| pxTopOfStack--; |
| *pxTopOfStack = ( StackType_t ) 0xdddd; |
| pxTopOfStack--; |
| *pxTopOfStack = ( StackType_t ) pvParameters; |
| pxTopOfStack--; |
| *pxTopOfStack = ( StackType_t ) 0xbbbb; |
| pxTopOfStack--; |
| *pxTopOfStack = ( StackType_t ) 0xaaaa; |
| pxTopOfStack--; |
| *pxTopOfStack = ( StackType_t ) 0x9999; |
| pxTopOfStack--; |
| *pxTopOfStack = ( StackType_t ) 0x8888; |
| pxTopOfStack--; |
| *pxTopOfStack = ( StackType_t ) 0x5555; |
| pxTopOfStack--; |
| *pxTopOfStack = ( StackType_t ) 0x6666; |
| pxTopOfStack--; |
| *pxTopOfStack = ( StackType_t ) 0x5555; |
| pxTopOfStack--; |
| *pxTopOfStack = ( StackType_t ) 0x4444; |
| pxTopOfStack--; |
| #else /* ifdef PRELOAD_REGISTER_VALUES */ |
| pxTopOfStack -= 3; |
| *pxTopOfStack = ( StackType_t ) pvParameters; |
| pxTopOfStack -= 9; |
| #endif /* ifdef PRELOAD_REGISTER_VALUES */ |
| |
| |
| /* A variable is used to keep track of the critical section nesting. |
| * This variable has to be stored as part of the task context and is |
| * initially set to zero. */ |
| *pxTopOfStack = ( StackType_t ) portNO_CRITICAL_SECTION_NESTING; |
| |
| /* Return a pointer to the top of the stack we have generated so this can |
| * be stored in the task control block for the task. */ |
| return pxTopOfStack; |
| } |
| /*-----------------------------------------------------------*/ |
| |
| void vPortEndScheduler( void ) |
| { |
| /* It is unlikely that the MSP430 port will get stopped. If required simply |
| * disable the tick interrupt here. */ |
| } |
| /*-----------------------------------------------------------*/ |
| |
| /* |
| * Hardware initialisation to generate the RTOS tick. |
| */ |
| void vPortSetupTimerInterrupt( void ) |
| { |
| vApplicationSetupTimerInterrupt(); |
| } |
| /*-----------------------------------------------------------*/ |
| |
| #pragma vector=configTICK_VECTOR |
| __interrupt __raw void vTickISREntry( void ) |
| { |
| extern void vPortTickISR( void ); |
| |
| __bic_SR_register_on_exit( SCG1 + SCG0 + OSCOFF + CPUOFF ); |
| vPortTickISR(); |
| } |