From 94367d247a8a8a20d5ab958c6ef0ac3c38f6a420 Mon Sep 17 00:00:00 2001 From: Alexandru Niculae - M17336 Date: Wed, 29 Jul 2020 17:36:46 +0300 Subject: [PATCH] Added portable/IAR/{AVR_AVRDx, AVR_Mega0 folders. --- portable/IAR/AVR_AVRDx/port.c | 293 ++++++++++++++++++++++++++ portable/IAR/AVR_AVRDx/porthardware.h | 94 +++++++++ portable/IAR/AVR_AVRDx/portmacro.h | 105 +++++++++ portable/IAR/AVR_AVRDx/portmacro.s90 | 254 ++++++++++++++++++++++ portable/IAR/AVR_Mega0/port.c | 291 +++++++++++++++++++++++++ portable/IAR/AVR_Mega0/porthardware.h | 82 +++++++ portable/IAR/AVR_Mega0/portmacro.h | 105 +++++++++ portable/IAR/AVR_Mega0/portmacro.s90 | 248 ++++++++++++++++++++++ 8 files changed, 1472 insertions(+) create mode 100644 portable/IAR/AVR_AVRDx/port.c create mode 100644 portable/IAR/AVR_AVRDx/porthardware.h create mode 100644 portable/IAR/AVR_AVRDx/portmacro.h create mode 100644 portable/IAR/AVR_AVRDx/portmacro.s90 create mode 100644 portable/IAR/AVR_Mega0/port.c create mode 100644 portable/IAR/AVR_Mega0/porthardware.h create mode 100644 portable/IAR/AVR_Mega0/portmacro.h create mode 100644 portable/IAR/AVR_Mega0/portmacro.s90 diff --git a/portable/IAR/AVR_AVRDx/port.c b/portable/IAR/AVR_AVRDx/port.c new file mode 100644 index 000000000..824c1aa4e --- /dev/null +++ b/portable/IAR/AVR_AVRDx/port.c @@ -0,0 +1,293 @@ +/* + * FreeRTOS Kernel V10.0.0 + * Copyright (C) 2017 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. If you wish to use our Amazon + * FreeRTOS name, please do so in a fair use way that does not cause confusion. + * + * 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 + * + * 1 tab == 4 spaces! + */ + +#include +#include "porthardware.h" +#include "FreeRTOS.h" +#include "task.h" + +/*----------------------------------------------------------- + * Implementation of functions defined in portable.h for the AVR port. + *----------------------------------------------------------*/ + +/* Start tasks with interrupts enables. */ +#define portFLAGS_INT_ENABLED ((StackType_t) 0x80) + +/*-----------------------------------------------------------*/ + + +#define portBYTES_USED_BY_RETURN_ADDRESS 2 +#define portNO_CRITICAL_NESTING ( ( UBaseType_t ) 0 ) + +/* Stores the critical section nesting. This must not be initialised to 0. +It will be initialised when a task starts. */ +UBaseType_t uxCriticalNesting = 0x50; +/* + * Setup timer to generate a tick interrupt. + */ +static void prvSetupTimerInterrupt(void); + +/* + * The IAR compiler does not have full support for inline assembler, so + * these are defined in the portmacro assembler file. + */ +extern void vPortYieldFromTick( void ); +extern void vPortStart( void ); + +/*-----------------------------------------------------------*/ + +/* + * See header file for description. + */ +StackType_t *pxPortInitialiseStack(StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters) +{ +uint16_t usAddress; +StackType_t *pxTopOfHardwareStack; + /* Simulate how the stack would look after a call to vPortYield(). */ + + /*lint -e950 -e611 -e923 Lint doesn't like this much - but nothing I can do about it. */ + + /* The IAR compiler requires two stacks per task. First there is the + hardware call stack which uses the AVR stack pointer. Second there is the + software stack (local variables, parameter passing, etc.) which uses the + AVR Y register. + This function places both stacks within the memory block passed in as the + first parameter. The hardware stack is placed at the bottom of the memory + block. A gap is then left for the hardware stack to grow. Next the software + stack is placed. The amount of space between the software and hardware + stacks is defined by configCALL_STACK_SIZE. + The first part of the stack is the hardware stack. Place the start + address of the task on the hardware stack. */ + + /* Place a few bytes of known values on the bottom of the stack. + This is just useful for debugging. */ + //*pxTopOfStack = 0x11; + //pxTopOfStack--; + //*pxTopOfStack = 0x22; + //pxTopOfStack--; + //*pxTopOfStack = 0x33; + //pxTopOfStack--; + + /* Remember where the top of the hardware stack is - this is required + below. */ + pxTopOfHardwareStack = pxTopOfStack; + + usAddress = ( uint16_t ) pxCode; + *pxTopOfStack = ( StackType_t ) ( usAddress & ( uint16_t ) 0x00ff ); + pxTopOfStack--; + + usAddress >>= 8; + *pxTopOfStack = ( StackType_t ) ( usAddress & ( uint16_t ) 0x00ff ); + pxTopOfStack--; + + /* Leave enough space for the hardware stack before starting the software + stack. The '- 2' is because we have already used two spaces for the + address of the start of the task. */ + pxTopOfStack -= ( configCALL_STACK_SIZE - 2 ); + + /* Next simulate the stack as if after a call to portSAVE_CONTEXT(). + portSAVE_CONTEXT places the flags on the stack immediately after r0 + to ensure the interrupts get disabled as soon as possible, and so ensuring + the stack use is minimal should a context switch interrupt occur. */ + *pxTopOfStack = ( StackType_t ) 0x00; /* R0 */ + pxTopOfStack--; + *pxTopOfStack = portFLAGS_INT_ENABLED; + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x00; /* RAMPZ */ + pxTopOfStack--; + + /* Next place the address of the hardware stack. This is required so + the AVR stack pointer can be restored to point to the hardware stack. */ + pxTopOfHardwareStack -= portBYTES_USED_BY_RETURN_ADDRESS; + usAddress = ( uint16_t ) pxTopOfHardwareStack; + + /* SPL */ + *pxTopOfStack = ( StackType_t ) ( usAddress & ( uint16_t ) 0x00ff ); + pxTopOfStack--; + + /* SPH */ + usAddress >>= 8; + *pxTopOfStack = ( StackType_t ) ( usAddress & ( uint16_t ) 0x00ff ); + pxTopOfStack--; + + /* Now the remaining registers. */ + *pxTopOfStack = ( StackType_t ) 0x01; /* R1 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x02; /* R2 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x03; /* R3 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x04; /* R4 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x05; /* R5 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x06; /* R6 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x07; /* R7 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x08; /* R8 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x09; /* R9 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x10; /* R10 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x11; /* R11 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x12; /* R12 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x13; /* R13 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x14; /* R14 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x15; /* R15 */ + pxTopOfStack--; + + /* Place the parameter on the stack in the expected location. */ + usAddress = (uint16_t) pvParameters; + *pxTopOfStack = (StackType_t) (usAddress & (uint16_t) 0x00ff); + pxTopOfStack--; + + usAddress >>= 8; + *pxTopOfStack = (StackType_t) (usAddress & (uint16_t) 0x00ff); + pxTopOfStack--; + + *pxTopOfStack = ( StackType_t ) 0x18; /* R18 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x19; /* R19 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x20; /* R20 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x21; /* R21 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x22; /* R22 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x23; /* R23 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x24; /* R24 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x25; /* R25 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x26; /* R26 X */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x27; /* R27 */ + pxTopOfStack--; + + /* The Y register is not stored as it is used as the software stack and + gets saved into the task control block. */ + + *pxTopOfStack = ( StackType_t ) 0x30; /* R30 Z */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x031; /* R31 */ + + pxTopOfStack--; + *pxTopOfStack = portNO_CRITICAL_NESTING; /* Critical nesting is zero when the task starts. */ + + /*lint +e950 +e611 +e923 */ + + return pxTopOfStack; +} +/*-----------------------------------------------------------*/ + +BaseType_t xPortStartScheduler(void) +{ + /* Setup the hardware to generate the tick. */ + prvSetupTimerInterrupt(); + + /* Restore the context of the first task that is going to run. + Normally we would just call portRESTORE_CONTEXT() here, but as the IAR + compiler does not fully support inline assembler we have to make a call.*/ + vPortStart(); + + /* Should not get here. */ + return pdTRUE; +} +/*-----------------------------------------------------------*/ + +void vPortEndScheduler(void) +{ + /* vPortEndScheduler is not implemented in this port. */ +} + +/*-----------------------------------------------------------*/ + +/* + * Setup timer to generate a tick interrupt. + */ +static void prvSetupTimerInterrupt(void) +{ + TICK_init(); +} + +/*-----------------------------------------------------------*/ + +#if configUSE_PREEMPTION == 1 +/* + * Tick ISR for preemptive scheduler. We can use a naked attribute as + * the context is saved at the start of vPortYieldFromTick(). The tick + * count is incremented after the context is saved. + */ + +__task void TICK_INT(void) +{ + vPortYieldFromTick(); + asm("reti"); +} +#else +/* + * 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 TICK_INT(void) +{ + /* Clear tick interrupt flag. */ + INT_FLAGS = INT_MASK; + + xTaskIncrementTick(); +} +#endif + +/*-----------------------------------------------------------*/ + +void vPortEnterCritical( void ) +{ + portDISABLE_INTERRUPTS(); + uxCriticalNesting++; +} + +/*-----------------------------------------------------------*/ + +void vPortExitCritical( void ) +{ + uxCriticalNesting--; + if( uxCriticalNesting == portNO_CRITICAL_NESTING ) + { + portENABLE_INTERRUPTS(); + } +} diff --git a/portable/IAR/AVR_AVRDx/porthardware.h b/portable/IAR/AVR_AVRDx/porthardware.h new file mode 100644 index 000000000..195d881aa --- /dev/null +++ b/portable/IAR/AVR_AVRDx/porthardware.h @@ -0,0 +1,94 @@ +#ifndef PORTHARDWARE_H +#define PORTHARDWARE_H + +#include +#include "FreeRTOSConfig.h" + +/*-----------------------------------------------------------*/ + +#if ( configUSE_TIMER_INSTANCE == 0 ) + + #define TICK_INT_vect TCB0_INT_vect + #define INT_FLAGS TCB0_INTFLAGS + #define INT_MASK TCB_CAPT_bm + + #define TICK_init() { \ + TCB0.CCMP = configCPU_CLOCK_HZ / configTICK_RATE_HZ; \ + TCB0.INTCTRL = TCB_CAPT_bm; \ + TCB0.CTRLA = TCB_ENABLE_bm; \ + } + +#elif ( configUSE_TIMER_INSTANCE == 1 ) + + #define TICK_INT_vect TCB1_INT_vect + #define INT_FLAGS TCB1_INTFLAGS + #define INT_MASK TCB_CAPT_bm + + #define TICK_init() { \ + TCB1.CCMP = configCPU_CLOCK_HZ / configTICK_RATE_HZ; \ + TCB1.INTCTRL = TCB_CAPT_bm; \ + TCB1.CTRLA = TCB_ENABLE_bm; \ + } + +#elif ( configUSE_TIMER_INSTANCE == 2 ) + + #define TICK_INT_vect TCB2_INT_vect + #define INT_FLAGS TCB2_INTFLAGS + #define INT_MASK TCB_CAPT_bm + + #define TICK_init() { \ + TCB2.CCMP = configCPU_CLOCK_HZ / configTICK_RATE_HZ; \ + TCB2.INTCTRL = TCB_CAPT_bm; \ + TCB2.CTRLA = TCB_ENABLE_bm; \ + } + +#elif ( configUSE_TIMER_INSTANCE == 3 ) + + #define TICK_INT_vect TCB3_INT_vect + #define INT_FLAGS TCB3_INTFLAGS + #define INT_MASK TCB_CAPT_bm + + #define TICK_init() { \ + TCB3.CCMP = configCPU_CLOCK_HZ / configTICK_RATE_HZ; \ + TCB3.INTCTRL = TCB_CAPT_bm; \ + TCB3.CTRLA = TCB_ENABLE_bm; \ + } + +#elif ( configUSE_TIMER_INSTANCE == 4 ) + + #define TICK_INT_vect TCB4_INT_vect + #define INT_FLAGS TCB4_INTFLAGS + #define INT_MASK TCB_CAPT_bm + + #define TICK_init() { \ + TCB4.CCMP = configCPU_CLOCK_HZ / configTICK_RATE_HZ; \ + TCB4.INTCTRL = TCB_CAPT_bm; \ + TCB4.CTRLA = TCB_ENABLE_bm; \ + } + +#elif ( configUSE_TIMER_INSTANCE == 5 ) + + #define TICK_INT_vect RTC_CNT_vect + #define INT_FLAGS RTC_INTFLAGS + #define INT_MASK RTC_OVF_bm + + /* Hertz to period for RTC setup */ + #define RTC_PERIOD_HZ(x) ( 32768 * ( ( 1.0 / x ) ) ) + #define TICK_init() { \ + while (RTC.STATUS > 0); \ + RTC.CTRLA = RTC_PRESCALER_DIV1_gc | 1 << RTC_RTCEN_bp; \ + RTC.PER = RTC_PERIOD_HZ(configTICK_RATE_HZ); \ + RTC.INTCTRL |= 1 << RTC_OVF_bp; \ + } + +#else + #undef TICK_INT_vect + #undef INT_FLAGS + #undef INT_MASK + #undef TICK_init() + #error Invalid timer setting. +#endif + +/*-----------------------------------------------------------*/ + +#endif /* PORTHARDWARE_H */ diff --git a/portable/IAR/AVR_AVRDx/portmacro.h b/portable/IAR/AVR_AVRDx/portmacro.h new file mode 100644 index 000000000..555f41e10 --- /dev/null +++ b/portable/IAR/AVR_AVRDx/portmacro.h @@ -0,0 +1,105 @@ +/* + * FreeRTOS Kernel V10.0.0 + * Copyright (C) 2017 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. If you wish to use our Amazon + * FreeRTOS name, please do so in a fair use way that does not cause confusion. + * + * 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 + * + * 1 tab == 4 spaces! + */ + +#ifndef PORTMACRO_H +#define PORTMACRO_H + +#ifdef __cplusplus +extern "C" { +#endif + +/*----------------------------------------------------------- + * Port specific definitions. + * + * The settings in this file configure FreeRTOS correctly for the + * given hardware and compiler. + * + * These settings should not be altered. + *----------------------------------------------------------- + */ + +/* Type definitions. */ +#define portCHAR char +#define portFLOAT float +#define portDOUBLE double +#define portLONG long +#define portSHORT int +#define portSTACK_TYPE uint8_t +#define portBASE_TYPE char + +#define portPOINTER_SIZE_TYPE uint16_t + +typedef portSTACK_TYPE StackType_t; +typedef signed char BaseType_t; +typedef unsigned char UBaseType_t; + +#if (configUSE_16_BIT_TICKS == 1) + typedef uint16_t TickType_t; + #define portMAX_DELAY (TickType_t)0xffff +#else + typedef uint32_t TickType_t; + #define portMAX_DELAY (TickType_t)0xffffffffUL +#endif + +/*-----------------------------------------------------------*/ + +/* Critical section management. */ +extern void vPortEnterCritical( void ); +extern void vPortExitCritical( void ); + +#define portENTER_CRITICAL() vPortEnterCritical() +#define portEXIT_CRITICAL() vPortExitCritical() + +#define portDISABLE_INTERRUPTS() asm( "cli" ) +#define portENABLE_INTERRUPTS() asm( "sei" ) +/*-----------------------------------------------------------*/ + +/* Architecture specifics. */ +#define portSTACK_GROWTH (-1) +#define portTICK_PERIOD_MS ((TickType_t)1000 / configTICK_RATE_HZ) +#define portBYTE_ALIGNMENT 1 +#define portNOP() asm( "nop" ) +/*-----------------------------------------------------------*/ + +/* Kernel utilities. */ +extern void vPortYield(void); +#define portYIELD() vPortYield() + +extern void vPortYieldFromISR(void); +#define portYIELD_FROM_ISR() vPortYieldFromISR() +/*-----------------------------------------------------------*/ + +/* Task function macros as described on the FreeRTOS.org WEB site. */ +#define portTASK_FUNCTION_PROTO(vFunction, pvParameters) void vFunction(void *pvParameters) +#define portTASK_FUNCTION(vFunction, pvParameters) void vFunction(void *pvParameters) + +#ifdef __cplusplus +} +#endif + +#endif /* PORTMACRO_H */ diff --git a/portable/IAR/AVR_AVRDx/portmacro.s90 b/portable/IAR/AVR_AVRDx/portmacro.s90 new file mode 100644 index 000000000..70a12ec44 --- /dev/null +++ b/portable/IAR/AVR_AVRDx/portmacro.s90 @@ -0,0 +1,254 @@ +;/* +; * 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 +; * +; * 1 tab == 4 spaces! +; */ + +#include "porthardware.h" + +; Declare all extern symbols here - including any ISRs that are referenced in +; the vector table. + +; ISR functions +; ------------- +EXTERN TICK_INT + +; Functions used by scheduler +; --------------------------- +EXTERN vTaskSwitchContext +EXTERN pxCurrentTCB +EXTERN xTaskIncrementTick +EXTERN uxCriticalNesting + +; Functions implemented in this file +; ---------------------------------- +PUBLIC vPortYield +PUBLIC vPortYieldFromTick +PUBLIC vPortYieldFromISR +PUBLIC vPortStart + +; Interrupt vector table. +; ----------------------- +; +; For simplicity the RTOS tick interrupt routine uses the __task keyword. +; As the IAR compiler does not permit a function to be declared using both +; __task and __interrupt, the use of __task necessitates that the interrupt +; vector table be setup manually. +; +; To write an ISR, implement the ISR function using the __interrupt keyword +; but do not install the interrupt using the "#pragma vector=ABC" method. +; Instead manually place the name of the ISR in the vector table using an +; ORG and jmp instruction as demonstrated below. +; You will also have to add an EXTERN statement at the top of the file. + + ASEG + + ORG TICK_INT_vect ; Vector address + jmp TICK_INT ; ISR + + RSEG CODE + +CLR_INT MACRO FLAG_REG, FLAG_MASK + st -y, r16 + ldi r16, FLAG_MASK + sts FLAG_REG, r16 + ld r16, y+ + + ENDM + +; Saving and Restoring a Task Context and Task Switching +; ------------------------------------------------------ +; +; The IAR compiler does not fully support inline assembler, so saving and +; restoring a task context has to be written in an asm file. +; +; vPortYield() and vPortYieldFromTick() are usually written in C. Doing +; so in this case would required calls to be made to portSAVE_CONTEXT() and +; portRESTORE_CONTEXT(). This is dis-advantageous as the context switch +; function would require two extra jump and return instructions over the +; WinAVR equivalent. +; +; To avoid this I have opted to implement both vPortYield() and +; vPortYieldFromTick() in this assembly file. For convenience +; portSAVE_CONTEXT and portRESTORE_CONTEXT are implemented as macros. + +portSAVE_CONTEXT MACRO + st -y, r0 ; First save the r0 register - we need to use this. + in r0, SREG ; Obtain the SREG value so we can disable interrupts... + cli ; ... as soon as possible. + st -y, r0 ; Store the SREG as it was before we disabled interrupts. + + in r0, RAMPZ + st -y, r0 + + in r0, SPL ; Next store the hardware stack pointer. The IAR... + st -y, r0 ; ... compiler uses the hardware stack as a call stack ... + in r0, SPH ; ... only. + st -y, r0 + + st -y, r1 ; Now store the rest of the registers. Dont store the ... + st -y, r2 ; ... the Y register here as it is used as the software + st -y, r3 ; stack pointer and will get saved into the TCB. + st -y, r4 + st -y, r5 + st -y, r6 + st -y, r7 + st -y, r8 + st -y, r9 + st -y, r10 + st -y, r11 + st -y, r12 + st -y, r13 + st -y, r14 + st -y, r15 + st -y, r16 + st -y, r17 + st -y, r18 + st -y, r19 + st -y, r20 + st -y, r21 + st -y, r22 + st -y, r23 + st -y, r24 + st -y, r25 + st -y, r26 + st -y, r27 + st -y, r30 + st -y, r31 + + lds r0, uxCriticalNesting + st -y, r0 ; Store the critical nesting counter. + + lds r26, pxCurrentTCB ; Finally save the software stack pointer (Y ... + lds r27, pxCurrentTCB + 1 ; ... register) into the TCB. + st x+, r28 + st x+, r29 + + ENDM + + +portRESTORE_CONTEXT MACRO + lds r26, pxCurrentTCB + lds r27, pxCurrentTCB + 1 ; Restore the software stack pointer from ... + ld r28, x+ ; the TCB into the software stack pointer (... + ld r29, x+ ; ... the Y register). + + ld r0, y+ + sts uxCriticalNesting, r0 + + ld r31, y+ ; Restore the registers down to R0. The Y + ld r30, y+ ; register is missing from this list as it + ld r27, y+ ; has already been restored. + ld r26, y+ + ld r25, y+ + ld r24, y+ + ld r23, y+ + ld r22, y+ + ld r21, y+ + ld r20, y+ + ld r19, y+ + ld r18, y+ + ld r17, y+ + ld r16, y+ + ld r15, y+ + ld r14, y+ + ld r13, y+ + ld r12, y+ + ld r11, y+ + ld r10, y+ + ld r9, y+ + ld r8, y+ + ld r7, y+ + ld r6, y+ + ld r5, y+ + ld r4, y+ + ld r3, y+ + ld r2, y+ + ld r1, y+ + + ld r0, y+ ; The next thing on the stack is the ... + out SPH, r0 ; ... hardware stack pointer. + ld r0, y+ + out SPL, r0 + + ld r0, y+ + out RAMPZ, r0 + + ld r0, y+ ; Next there is the SREG register. + out SREG, r0 + + ld r0, y+ ; Finally we have finished with r0, so restore r0. + + ENDM + + + +; vPortYield(), vPortYieldFromTick() and vPortYieldFromISR() +; ------------------------------------- +; +; Manual and preemptive context switch functions respectively. +; The IAR compiler does not fully support inline assembler, +; so these are implemented here rather than the more usually +; place of within port.c. + +vPortYield: + portSAVE_CONTEXT ; Save the context of the current task. + call vTaskSwitchContext ; Call the scheduler. + portRESTORE_CONTEXT ; Restore the context of whichever task the ... + ret ; ... scheduler decided should run. + +vPortYieldFromTick: + CLR_INT INT_FLAGS, INT_MASK ; Clear tick interrupt flag + + portSAVE_CONTEXT ; Save the context of the current task. + call xTaskIncrementTick ; Call the timer tick function. + tst r16 + breq SkipTaskSwitch + call vTaskSwitchContext ; Call the scheduler. + +SkipTaskSwitch: + portRESTORE_CONTEXT ; Restore the context of whichever task the ... + reti ; ... scheduler decided should run. + +vPortYieldFromISR: + portSAVE_CONTEXT ; Save the context of the current task. + call vTaskSwitchContext ; Call the scheduler. + portRESTORE_CONTEXT ; Restore the context of whichever task the ... + reti ; ... scheduler decided should run. + +; vPortStart() +; ------------ +; +; Again due to the lack of inline assembler, this is required +; to get access to the portRESTORE_CONTEXT macro. + +vPortStart: + portRESTORE_CONTEXT + ret + +; Just a filler for unused interrupt vectors. +vNoISR: + reti + + END diff --git a/portable/IAR/AVR_Mega0/port.c b/portable/IAR/AVR_Mega0/port.c new file mode 100644 index 000000000..9e34e1b5e --- /dev/null +++ b/portable/IAR/AVR_Mega0/port.c @@ -0,0 +1,291 @@ +/* + * FreeRTOS Kernel V10.0.0 + * Copyright (C) 2017 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. If you wish to use our Amazon + * FreeRTOS name, please do so in a fair use way that does not cause confusion. + * + * 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 + * + * 1 tab == 4 spaces! + */ + +#include +#include "porthardware.h" +#include "FreeRTOS.h" +#include "task.h" + +/*----------------------------------------------------------- + * Implementation of functions defined in portable.h for the AVR port. + *----------------------------------------------------------*/ + +/* Start tasks with interrupts enables. */ +#define portFLAGS_INT_ENABLED ((StackType_t) 0x80) + +/*-----------------------------------------------------------*/ + + +#define portBYTES_USED_BY_RETURN_ADDRESS 2 +#define portNO_CRITICAL_NESTING ( ( UBaseType_t ) 0 ) + +/* Stores the critical section nesting. This must not be initialised to 0. +It will be initialised when a task starts. */ +UBaseType_t uxCriticalNesting = 0x50; +/* + * Setup timer to generate a tick interrupt. + */ +static void prvSetupTimerInterrupt(void); + +/* + * The IAR compiler does not have full support for inline assembler, so + * these are defined in the portmacro assembler file. + */ +extern void vPortYieldFromTick( void ); +extern void vPortStart( void ); + +/*-----------------------------------------------------------*/ + +/* + * See header file for description. + */ +StackType_t *pxPortInitialiseStack(StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters) +{ +uint16_t usAddress; +StackType_t *pxTopOfHardwareStack; + /* Simulate how the stack would look after a call to vPortYield(). */ + + /*lint -e950 -e611 -e923 Lint doesn't like this much - but nothing I can do about it. */ + + /* The IAR compiler requires two stacks per task. First there is the + hardware call stack which uses the AVR stack pointer. Second there is the + software stack (local variables, parameter passing, etc.) which uses the + AVR Y register. + This function places both stacks within the memory block passed in as the + first parameter. The hardware stack is placed at the bottom of the memory + block. A gap is then left for the hardware stack to grow. Next the software + stack is placed. The amount of space between the software and hardware + stacks is defined by configCALL_STACK_SIZE. + The first part of the stack is the hardware stack. Place the start + address of the task on the hardware stack. */ + + /* Place a few bytes of known values on the bottom of the stack. + This is just useful for debugging. */ + //*pxTopOfStack = 0x11; + //pxTopOfStack--; + //*pxTopOfStack = 0x22; + //pxTopOfStack--; + //*pxTopOfStack = 0x33; + //pxTopOfStack--; + + /* Remember where the top of the hardware stack is - this is required + below. */ + pxTopOfHardwareStack = pxTopOfStack; + + usAddress = ( uint16_t ) pxCode; + *pxTopOfStack = ( StackType_t ) ( usAddress & ( uint16_t ) 0x00ff ); + pxTopOfStack--; + + usAddress >>= 8; + *pxTopOfStack = ( StackType_t ) ( usAddress & ( uint16_t ) 0x00ff ); + pxTopOfStack--; + + /* Leave enough space for the hardware stack before starting the software + stack. The '- 2' is because we have already used two spaces for the + address of the start of the task. */ + pxTopOfStack -= ( configCALL_STACK_SIZE - 2 ); + + /* Next simulate the stack as if after a call to portSAVE_CONTEXT(). + portSAVE_CONTEXT places the flags on the stack immediately after r0 + to ensure the interrupts get disabled as soon as possible, and so ensuring + the stack use is minimal should a context switch interrupt occur. */ + *pxTopOfStack = ( StackType_t ) 0x00; /* R0 */ + pxTopOfStack--; + *pxTopOfStack = portFLAGS_INT_ENABLED; + pxTopOfStack--; + + /* Next place the address of the hardware stack. This is required so + the AVR stack pointer can be restored to point to the hardware stack. */ + pxTopOfHardwareStack -= portBYTES_USED_BY_RETURN_ADDRESS; + usAddress = ( uint16_t ) pxTopOfHardwareStack; + + /* SPL */ + *pxTopOfStack = ( StackType_t ) ( usAddress & ( uint16_t ) 0x00ff ); + pxTopOfStack--; + + /* SPH */ + usAddress >>= 8; + *pxTopOfStack = ( StackType_t ) ( usAddress & ( uint16_t ) 0x00ff ); + pxTopOfStack--; + + /* Now the remaining registers. */ + *pxTopOfStack = ( StackType_t ) 0x01; /* R1 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x02; /* R2 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x03; /* R3 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x04; /* R4 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x05; /* R5 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x06; /* R6 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x07; /* R7 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x08; /* R8 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x09; /* R9 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x10; /* R10 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x11; /* R11 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x12; /* R12 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x13; /* R13 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x14; /* R14 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x15; /* R15 */ + pxTopOfStack--; + + /* Place the parameter on the stack in the expected location. */ + usAddress = (uint16_t) pvParameters; + *pxTopOfStack = (StackType_t) (usAddress & (uint16_t) 0x00ff); + pxTopOfStack--; + + usAddress >>= 8; + *pxTopOfStack = (StackType_t) (usAddress & (uint16_t) 0x00ff); + pxTopOfStack--; + + *pxTopOfStack = ( StackType_t ) 0x18; /* R18 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x19; /* R19 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x20; /* R20 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x21; /* R21 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x22; /* R22 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x23; /* R23 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x24; /* R24 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x25; /* R25 */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x26; /* R26 X */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x27; /* R27 */ + pxTopOfStack--; + + /* The Y register is not stored as it is used as the software stack and + gets saved into the task control block. */ + + *pxTopOfStack = ( StackType_t ) 0x30; /* R30 Z */ + pxTopOfStack--; + *pxTopOfStack = ( StackType_t ) 0x031; /* R31 */ + + pxTopOfStack--; + *pxTopOfStack = portNO_CRITICAL_NESTING; /* Critical nesting is zero when the task starts. */ + + /*lint +e950 +e611 +e923 */ + + return pxTopOfStack; +} +/*-----------------------------------------------------------*/ + +BaseType_t xPortStartScheduler(void) +{ + /* Setup the hardware to generate the tick. */ + prvSetupTimerInterrupt(); + + /* Restore the context of the first task that is going to run. + Normally we would just call portRESTORE_CONTEXT() here, but as the IAR + compiler does not fully support inline assembler we have to make a call.*/ + vPortStart(); + + /* Should not get here. */ + return pdTRUE; +} +/*-----------------------------------------------------------*/ + +void vPortEndScheduler(void) +{ + /* vPortEndScheduler is not implemented in this port. */ +} + +/*-----------------------------------------------------------*/ + +/* + * Setup timer to generate a tick interrupt. + */ +static void prvSetupTimerInterrupt(void) +{ + TICK_init(); +} + +/*-----------------------------------------------------------*/ + +#if configUSE_PREEMPTION == 1 +/* + * Tick ISR for preemptive scheduler. We can use a naked attribute as + * the context is saved at the start of vPortYieldFromTick(). The tick + * count is incremented after the context is saved. + */ + +__task void TICK_INT(void) +{ + vPortYieldFromTick(); + asm("reti"); +} +#else +/* + * 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 TICK_INT(void) +{ + /* Clear tick interrupt flag. */ + INT_FLAGS = INT_MASK; + + xTaskIncrementTick(); +} +#endif + +/*-----------------------------------------------------------*/ + +void vPortEnterCritical( void ) +{ + portDISABLE_INTERRUPTS(); + uxCriticalNesting++; +} + +/*-----------------------------------------------------------*/ + +void vPortExitCritical( void ) +{ + uxCriticalNesting--; + if( uxCriticalNesting == portNO_CRITICAL_NESTING ) + { + portENABLE_INTERRUPTS(); + } +} diff --git a/portable/IAR/AVR_Mega0/porthardware.h b/portable/IAR/AVR_Mega0/porthardware.h new file mode 100644 index 000000000..5468bdabe --- /dev/null +++ b/portable/IAR/AVR_Mega0/porthardware.h @@ -0,0 +1,82 @@ +#ifndef PORTHARDWARE_H +#define PORTHARDWARE_H + +#include +#include "FreeRTOSConfig.h" + +/*-----------------------------------------------------------*/ + +#if ( configUSE_TIMER_INSTANCE == 0 ) + + #define TICK_INT_vect TCB0_INT_vect + #define INT_FLAGS TCB0_INTFLAGS + #define INT_MASK TCB_CAPT_bm + + #define TICK_init() { \ + TCB0.CCMP = configCPU_CLOCK_HZ / configTICK_RATE_HZ; \ + TCB0.INTCTRL = TCB_CAPT_bm; \ + TCB0.CTRLA = TCB_ENABLE_bm; \ + } + +#elif ( configUSE_TIMER_INSTANCE == 1 ) + + #define TICK_INT_vect TCB1_INT_vect + #define INT_FLAGS TCB1_INTFLAGS + #define INT_MASK TCB_CAPT_bm + + #define TICK_init() { \ + TCB1.CCMP = configCPU_CLOCK_HZ / configTICK_RATE_HZ; \ + TCB1.INTCTRL = TCB_CAPT_bm; \ + TCB1.CTRLA = TCB_ENABLE_bm; \ + } + +#elif ( configUSE_TIMER_INSTANCE == 2 ) + + #define TICK_INT_vect TCB2_INT_vect + #define INT_FLAGS TCB2_INTFLAGS + #define INT_MASK TCB_CAPT_bm + + #define TICK_init() { \ + TCB2.CCMP = configCPU_CLOCK_HZ / configTICK_RATE_HZ; \ + TCB2.INTCTRL = TCB_CAPT_bm; \ + TCB2.CTRLA = TCB_ENABLE_bm; \ + } + +#elif ( configUSE_TIMER_INSTANCE == 3 ) + + #define TICK_INT_vect TCB3_INT_vect + #define INT_FLAGS TCB3_INTFLAGS + #define INT_MASK TCB_CAPT_bm + + #define TICK_init() { \ + TCB3.CCMP = configCPU_CLOCK_HZ / configTICK_RATE_HZ; \ + TCB3.INTCTRL = TCB_CAPT_bm; \ + TCB3.CTRLA = TCB_ENABLE_bm; \ + } + +#elif ( configUSE_TIMER_INSTANCE == 4 ) + + #define TICK_INT_vect RTC_CNT_vect + #define INT_FLAGS RTC_INTFLAGS + #define INT_MASK RTC_OVF_bm + + /* Hertz to period for RTC setup */ + #define RTC_PERIOD_HZ(x) ( 32768 * ( ( 1.0 / x ) ) ) + #define TICK_init() { \ + while (RTC.STATUS > 0); \ + RTC.CTRLA = RTC_PRESCALER_DIV1_gc | 1 << RTC_RTCEN_bp; \ + RTC.PER = RTC_PERIOD_HZ(configTICK_RATE_HZ); \ + RTC.INTCTRL |= 1 << RTC_OVF_bp; \ + } + +#else + #undef TICK_INT_vect + #undef INT_FLAGS + #undef INT_MASK + #undef TICK_init() + #error Invalid timer setting. +#endif + +/*-----------------------------------------------------------*/ + +#endif /* PORTHARDWARE_H */ diff --git a/portable/IAR/AVR_Mega0/portmacro.h b/portable/IAR/AVR_Mega0/portmacro.h new file mode 100644 index 000000000..555f41e10 --- /dev/null +++ b/portable/IAR/AVR_Mega0/portmacro.h @@ -0,0 +1,105 @@ +/* + * FreeRTOS Kernel V10.0.0 + * Copyright (C) 2017 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. If you wish to use our Amazon + * FreeRTOS name, please do so in a fair use way that does not cause confusion. + * + * 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 + * + * 1 tab == 4 spaces! + */ + +#ifndef PORTMACRO_H +#define PORTMACRO_H + +#ifdef __cplusplus +extern "C" { +#endif + +/*----------------------------------------------------------- + * Port specific definitions. + * + * The settings in this file configure FreeRTOS correctly for the + * given hardware and compiler. + * + * These settings should not be altered. + *----------------------------------------------------------- + */ + +/* Type definitions. */ +#define portCHAR char +#define portFLOAT float +#define portDOUBLE double +#define portLONG long +#define portSHORT int +#define portSTACK_TYPE uint8_t +#define portBASE_TYPE char + +#define portPOINTER_SIZE_TYPE uint16_t + +typedef portSTACK_TYPE StackType_t; +typedef signed char BaseType_t; +typedef unsigned char UBaseType_t; + +#if (configUSE_16_BIT_TICKS == 1) + typedef uint16_t TickType_t; + #define portMAX_DELAY (TickType_t)0xffff +#else + typedef uint32_t TickType_t; + #define portMAX_DELAY (TickType_t)0xffffffffUL +#endif + +/*-----------------------------------------------------------*/ + +/* Critical section management. */ +extern void vPortEnterCritical( void ); +extern void vPortExitCritical( void ); + +#define portENTER_CRITICAL() vPortEnterCritical() +#define portEXIT_CRITICAL() vPortExitCritical() + +#define portDISABLE_INTERRUPTS() asm( "cli" ) +#define portENABLE_INTERRUPTS() asm( "sei" ) +/*-----------------------------------------------------------*/ + +/* Architecture specifics. */ +#define portSTACK_GROWTH (-1) +#define portTICK_PERIOD_MS ((TickType_t)1000 / configTICK_RATE_HZ) +#define portBYTE_ALIGNMENT 1 +#define portNOP() asm( "nop" ) +/*-----------------------------------------------------------*/ + +/* Kernel utilities. */ +extern void vPortYield(void); +#define portYIELD() vPortYield() + +extern void vPortYieldFromISR(void); +#define portYIELD_FROM_ISR() vPortYieldFromISR() +/*-----------------------------------------------------------*/ + +/* Task function macros as described on the FreeRTOS.org WEB site. */ +#define portTASK_FUNCTION_PROTO(vFunction, pvParameters) void vFunction(void *pvParameters) +#define portTASK_FUNCTION(vFunction, pvParameters) void vFunction(void *pvParameters) + +#ifdef __cplusplus +} +#endif + +#endif /* PORTMACRO_H */ diff --git a/portable/IAR/AVR_Mega0/portmacro.s90 b/portable/IAR/AVR_Mega0/portmacro.s90 new file mode 100644 index 000000000..4b117d7b6 --- /dev/null +++ b/portable/IAR/AVR_Mega0/portmacro.s90 @@ -0,0 +1,248 @@ +;/* +; * 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 +; * +; * 1 tab == 4 spaces! +; */ + +#include "porthardware.h" + +; Declare all extern symbols here - including any ISRs that are referenced in +; the vector table. + +; ISR functions +; ------------- +EXTERN TICK_INT + +; Functions used by scheduler +; --------------------------- +EXTERN vTaskSwitchContext +EXTERN pxCurrentTCB +EXTERN xTaskIncrementTick +EXTERN uxCriticalNesting + +; Functions implemented in this file +; ---------------------------------- +PUBLIC vPortYield +PUBLIC vPortYieldFromTick +PUBLIC vPortYieldFromISR +PUBLIC vPortStart + +; Interrupt vector table. +; ----------------------- +; +; For simplicity the RTOS tick interrupt routine uses the __task keyword. +; As the IAR compiler does not permit a function to be declared using both +; __task and __interrupt, the use of __task necessitates that the interrupt +; vector table be setup manually. +; +; To write an ISR, implement the ISR function using the __interrupt keyword +; but do not install the interrupt using the "#pragma vector=ABC" method. +; Instead manually place the name of the ISR in the vector table using an +; ORG and jmp instruction as demonstrated below. +; You will also have to add an EXTERN statement at the top of the file. + + ASEG + + ORG TICK_INT_vect ; Vector address + jmp TICK_INT ; ISR + + RSEG CODE + +CLR_INT MACRO FLAG_REG, FLAG_MASK + st -y, r16 + ldi r16, FLAG_MASK + sts FLAG_REG, r16 + ld r16, y+ + + ENDM + +; Saving and Restoring a Task Context and Task Switching +; ------------------------------------------------------ +; +; The IAR compiler does not fully support inline assembler, so saving and +; restoring a task context has to be written in an asm file. +; +; vPortYield() and vPortYieldFromTick() are usually written in C. Doing +; so in this case would required calls to be made to portSAVE_CONTEXT() and +; portRESTORE_CONTEXT(). This is dis-advantageous as the context switch +; function would require two extra jump and return instructions over the +; WinAVR equivalent. +; +; To avoid this I have opted to implement both vPortYield() and +; vPortYieldFromTick() in this assembly file. For convenience +; portSAVE_CONTEXT and portRESTORE_CONTEXT are implemented as macros. + +portSAVE_CONTEXT MACRO + st -y, r0 ; First save the r0 register - we need to use this. + in r0, SREG ; Obtain the SREG value so we can disable interrupts... + cli ; ... as soon as possible. + st -y, r0 ; Store the SREG as it was before we disabled interrupts. + + in r0, SPL ; Next store the hardware stack pointer. The IAR... + st -y, r0 ; ... compiler uses the hardware stack as a call stack ... + in r0, SPH ; ... only. + st -y, r0 + + st -y, r1 ; Now store the rest of the registers. Dont store the ... + st -y, r2 ; ... the Y register here as it is used as the software + st -y, r3 ; stack pointer and will get saved into the TCB. + st -y, r4 + st -y, r5 + st -y, r6 + st -y, r7 + st -y, r8 + st -y, r9 + st -y, r10 + st -y, r11 + st -y, r12 + st -y, r13 + st -y, r14 + st -y, r15 + st -y, r16 + st -y, r17 + st -y, r18 + st -y, r19 + st -y, r20 + st -y, r21 + st -y, r22 + st -y, r23 + st -y, r24 + st -y, r25 + st -y, r26 + st -y, r27 + st -y, r30 + st -y, r31 + + lds r0, uxCriticalNesting + st -y, r0 ; Store the critical nesting counter. + + lds r26, pxCurrentTCB ; Finally save the software stack pointer (Y ... + lds r27, pxCurrentTCB + 1 ; ... register) into the TCB. + st x+, r28 + st x+, r29 + + ENDM + + +portRESTORE_CONTEXT MACRO + lds r26, pxCurrentTCB + lds r27, pxCurrentTCB + 1 ; Restore the software stack pointer from ... + ld r28, x+ ; the TCB into the software stack pointer (... + ld r29, x+ ; ... the Y register). + + ld r0, y+ + sts uxCriticalNesting, r0 + + ld r31, y+ ; Restore the registers down to R0. The Y + ld r30, y+ ; register is missing from this list as it + ld r27, y+ ; has already been restored. + ld r26, y+ + ld r25, y+ + ld r24, y+ + ld r23, y+ + ld r22, y+ + ld r21, y+ + ld r20, y+ + ld r19, y+ + ld r18, y+ + ld r17, y+ + ld r16, y+ + ld r15, y+ + ld r14, y+ + ld r13, y+ + ld r12, y+ + ld r11, y+ + ld r10, y+ + ld r9, y+ + ld r8, y+ + ld r7, y+ + ld r6, y+ + ld r5, y+ + ld r4, y+ + ld r3, y+ + ld r2, y+ + ld r1, y+ + + ld r0, y+ ; The next thing on the stack is the ... + out SPH, r0 ; ... hardware stack pointer. + ld r0, y+ + out SPL, r0 + + ld r0, y+ ; Next there is the SREG register. + out SREG, r0 + + ld r0, y+ ; Finally we have finished with r0, so restore r0. + + ENDM + + + +; vPortYield(), vPortYieldFromTick() and vPortYieldFromISR() +; ------------------------------------- +; +; Manual and preemptive context switch functions respectively. +; The IAR compiler does not fully support inline assembler, +; so these are implemented here rather than the more usually +; place of within port.c. + +vPortYield: + portSAVE_CONTEXT ; Save the context of the current task. + call vTaskSwitchContext ; Call the scheduler. + portRESTORE_CONTEXT ; Restore the context of whichever task the ... + ret ; ... scheduler decided should run. + +vPortYieldFromTick: + CLR_INT INT_FLAGS, INT_MASK ; Clear tick interrupt flag + + portSAVE_CONTEXT ; Save the context of the current task. + call xTaskIncrementTick ; Call the timer tick function. + tst r16 + breq SkipTaskSwitch + call vTaskSwitchContext ; Call the scheduler. + +SkipTaskSwitch: + portRESTORE_CONTEXT ; Restore the context of whichever task the ... + reti ; ... scheduler decided should run. + +vPortYieldFromISR: + portSAVE_CONTEXT ; Save the context of the current task. + call vTaskSwitchContext ; Call the scheduler. + portRESTORE_CONTEXT ; Restore the context of whichever task the ... + reti ; ... scheduler decided should run. + +; vPortStart() +; ------------ +; +; Again due to the lack of inline assembler, this is required +; to get access to the portRESTORE_CONTEXT macro. + +vPortStart: + portRESTORE_CONTEXT + ret + +; Just a filler for unused interrupt vectors. +vNoISR: + reti + +END