/* * FreeRTOS Kernel V10.3.1 * Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved. * * 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. * * http://www.FreeRTOS.org * http://aws.amazon.com/freertos * */ /* Standard includes. */ #include /* Scheduler includes. */ #include "FreeRTOS.h" #include "task.h" /* The critical nesting value is initialised to a non zero value to ensure * interrupts don't accidentally become enabled before the scheduler is started. */ #define portINITIAL_CRITICAL_NESTING ( ( uint16_t ) 10 ) /* Initial PSW value allocated to a newly created task. * 1100011000000000 * ||||||||-------------- Fill byte * |||||||--------------- Carry Flag cleared * |||||----------------- In-service priority Flags set to low level * ||||------------------ Register bank Select 0 Flag cleared * |||------------------- Auxiliary Carry Flag cleared * ||-------------------- Register bank Select 1 Flag cleared * |--------------------- Zero Flag set * ---------------------- Global Interrupt Flag set (enabled) */ #define portPSW ( 0xc6UL ) /* 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; /* Most ports implement critical sections by placing the interrupt flags on * the stack before disabling interrupts. Exiting the critical section is then * simply a case of popping the flags from the stack. As 78K0 IAR does not use * a frame pointer this cannot be done as modifying the stack will clobber all * the stack variables. Instead 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 left 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. */ static void prvSetupTimerInterrupt( 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 ) { uint32_t * pulLocal; #if configMEMORY_MODE == 1 { /* Parameters are passed in on the stack, and written using a 32bit value * hence a space is left for the second two bytes. */ pxTopOfStack--; /* Write in the parameter value. */ pulLocal = ( uint32_t * ) pxTopOfStack; *pulLocal = ( uint32_t ) pvParameters; pxTopOfStack--; /* These values are just spacers. The return address of the function * would normally be written here. */ *pxTopOfStack = ( StackType_t ) 0xcdcd; pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0xcdcd; pxTopOfStack--; /* The start address / PSW value is also written in as a 32bit value, * so leave a space for the second two bytes. */ pxTopOfStack--; /* Task function start address combined with the PSW. */ pulLocal = ( uint32_t * ) pxTopOfStack; *pulLocal = ( ( ( uint32_t ) pxCode ) | ( portPSW << 24UL ) ); pxTopOfStack--; /* An initial value for the AX register. */ *pxTopOfStack = ( StackType_t ) 0x1111; pxTopOfStack--; } #else /* if configMEMORY_MODE == 1 */ { /* Task function address is written to the stack first. As it is * written as a 32bit value a space is left on the stack for the second * two bytes. */ pxTopOfStack--; /* Task function start address combined with the PSW. */ pulLocal = ( uint32_t * ) pxTopOfStack; *pulLocal = ( ( ( uint32_t ) pxCode ) | ( portPSW << 24UL ) ); pxTopOfStack--; /* The parameter is passed in AX. */ *pxTopOfStack = ( StackType_t ) pvParameters; pxTopOfStack--; } #endif /* if configMEMORY_MODE == 1 */ /* An initial value for the HL register. */ *pxTopOfStack = ( StackType_t ) 0x2222; pxTopOfStack--; /* CS and ES registers. */ *pxTopOfStack = ( StackType_t ) 0x0F00; pxTopOfStack--; /* Finally the remaining general purpose registers DE and BC */ *pxTopOfStack = ( StackType_t ) 0xDEDE; pxTopOfStack--; *pxTopOfStack = ( StackType_t ) 0xBCBC; pxTopOfStack--; /* Finally the critical section nesting count is set to zero when the task * first starts. */ *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; } /*-----------------------------------------------------------*/ BaseType_t xPortStartScheduler( void ) { /* Setup the hardware to generate the tick. Interrupts are disabled when * this function is called. */ prvSetupTimerInterrupt(); /* Restore the context of the first task that is going to run. */ vPortStart(); /* Should not get here as the tasks are now running! */ return pdTRUE; } /*-----------------------------------------------------------*/ void vPortEndScheduler( void ) { /* It is unlikely that the 78K0R port will get stopped. If required simply * disable the tick interrupt here. */ } /*-----------------------------------------------------------*/ static void prvSetupTimerInterrupt( void ) { /* Setup channel 5 of the TAU to generate the tick interrupt. */ /* First the Timer Array Unit has to be enabled. */ TAU0EN = 1; /* To configure the Timer Array Unit all Channels have to first be stopped. */ TT0 = 0xff; /* Interrupt of Timer Array Unit Channel 5 is disabled to set the interrupt * priority. */ TMMK05 = 1; /* Clear Timer Array Unit Channel 5 interrupt flag. */ TMIF05 = 0; /* Set Timer Array Unit Channel 5 interrupt priority */ TMPR005 = 0; TMPR105 = 0; /* Set Timer Array Unit Channel 5 Mode as interval timer. */ TMR05 = 0x0000; /* Set the compare match value according to the tick rate we want. */ TDR05 = ( TickType_t ) ( configCPU_CLOCK_HZ / configTICK_RATE_HZ ); /* Set Timer Array Unit Channel 5 output mode */ TOM0 &= ~0x0020; /* Set Timer Array Unit Channel 5 output level */ TOL0 &= ~0x0020; /* Set Timer Array Unit Channel 5 output enable */ TOE0 &= ~0x0020; /* Interrupt of Timer Array Unit Channel 5 enabled */ TMMK05 = 0; /* Start Timer Array Unit Channel 5.*/ TS0 |= 0x0020; } /*-----------------------------------------------------------*/