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FreeRTOS-Kernel/portable/GCC/MicroBlaze/port.c

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/*
* 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
*
*/
/*-----------------------------------------------------------
* Implementation of functions defined in portable.h for the MicroBlaze port.
*----------------------------------------------------------*/
/* Scheduler includes. */
#include "FreeRTOS.h"
#include "task.h"
/* Standard includes. */
#include <string.h>
/* Hardware includes. */
#include <xintc.h>
#include <xintc_i.h>
#include <xtmrctr.h>
#if ( configSUPPORT_DYNAMIC_ALLOCATION == 0 )
#error configSUPPORT_DYNAMIC_ALLOCATION must be set to 1 to use this port.
#endif
/* Tasks are started with interrupts enabled. */
#define portINITIAL_MSR_STATE ( ( StackType_t ) 0x02 )
/* Tasks are started with a critical section nesting of 0 - however prior
* to the scheduler being commenced we don't want the critical nesting level
* to reach zero, so it is initialised to a high value. */
#define portINITIAL_NESTING_VALUE ( 0xff )
/* Our hardware setup only uses one counter. */
#define portCOUNTER_0 0
/* The stack used by the ISR is filled with a known value to assist in
* debugging. */
#define portISR_STACK_FILL_VALUE 0x55555555
/* Counts the nesting depth of calls to portENTER_CRITICAL(). Each task
* maintains it's own count, so this variable is saved as part of the task
* context. */
volatile UBaseType_t uxCriticalNesting = portINITIAL_NESTING_VALUE;
/* To limit the amount of stack required by each task, this port uses a
* separate stack for interrupts. */
uint32_t * pulISRStack;
/*-----------------------------------------------------------*/
/*
* 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.
*/
static void prvSetupTimerInterrupt( void );
/*-----------------------------------------------------------*/
/*
* Initialise the stack of a task to look exactly as if a call to
* portSAVE_CONTEXT had been made.
*
* See the header file portable.h.
*/
StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
TaskFunction_t pxCode,
void * pvParameters )
{
extern void * _SDA2_BASE_;
extern void * _SDA_BASE_;
const uint32_t ulR2 = ( uint32_t ) &_SDA2_BASE_;
const uint32_t ulR13 = ( uint32_t ) &_SDA_BASE_;
/* Place a few bytes of known values on the bottom of the stack.
* This is essential for the Microblaze port and these lines must
* not be omitted. The parameter value will overwrite the
* 0x22222222 value during the function prologue. */
*pxTopOfStack = ( StackType_t ) 0x11111111;
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x22222222;
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x33333333;
pxTopOfStack--;
/* First stack an initial value for the critical section nesting. This
* is initialised to zero as tasks are started with interrupts enabled. */
*pxTopOfStack = ( StackType_t ) 0x00; /* R0. */
/* Place an initial value for all the general purpose registers. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) ulR2; /* R2 - small data area. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x03; /* R3. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x04; /* R4. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) pvParameters; /* R5 contains the function call parameters. */
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 ) 0x0a; /* R10. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x0b; /* R11. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x0c; /* R12. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) ulR13; /* R13 - small data read write area. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) pxCode; /* R14. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x0f; /* R15. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x10; /* R16. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x11; /* R17. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x12; /* R18. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x13; /* R19. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x14; /* R20. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x15; /* R21. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x16; /* R22. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x17; /* R23. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x18; /* R24. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x19; /* R25. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x1a; /* R26. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x1b; /* R27. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x1c; /* R28. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x1d; /* R29. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x1e; /* R30. */
pxTopOfStack--;
/* The MSR is stacked between R30 and R31. */
*pxTopOfStack = portINITIAL_MSR_STATE;
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x1f; /* R31. */
pxTopOfStack--;
/* 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 )
{
extern void( __FreeRTOS_interrupt_Handler )( void );
extern void( vStartFirstTask )( void );
/* Setup the FreeRTOS interrupt handler. Code copied from crt0.s. */
asm volatile ( "la r6, r0, __FreeRTOS_interrupt_handler \n\t" \
"sw r6, r1, r0 \n\t" \
"lhu r7, r1, r0 \n\t" \
"shi r7, r0, 0x12 \n\t" \
"shi r6, r0, 0x16 " );
/* Setup the hardware to generate the tick. Interrupts are disabled when
* this function is called. */
prvSetupTimerInterrupt();
/* Allocate the stack to be used by the interrupt handler. */
pulISRStack = ( uint32_t * ) pvPortMalloc( configMINIMAL_STACK_SIZE * sizeof( StackType_t ) );
/* Restore the context of the first task that is going to run. */
if( pulISRStack != NULL )
{
/* Fill the ISR stack with a known value to facilitate debugging. */
memset( pulISRStack, portISR_STACK_FILL_VALUE, configMINIMAL_STACK_SIZE * sizeof( StackType_t ) );
pulISRStack += ( configMINIMAL_STACK_SIZE - 1 );
/* Kick off the first task. */
vStartFirstTask();
}
/* Should not get here as the tasks are now running! */
return pdFALSE;
}
/*-----------------------------------------------------------*/
void vPortEndScheduler( void )
{
/* Not implemented. */
}
/*-----------------------------------------------------------*/
/*
* Manual context switch called by portYIELD or taskYIELD.
*/
void vPortYield( void )
{
extern void VPortYieldASM( void );
/* Perform the context switch in a critical section to assure it is
* not interrupted by the tick ISR. It is not a problem to do this as
* each task maintains it's own interrupt status. */
portENTER_CRITICAL();
/* Jump directly to the yield function to ensure there is no
* compiler generated prologue code. */
asm volatile ( "bralid r14, VPortYieldASM \n\t" \
"or r0, r0, r0 \n\t" );
portEXIT_CRITICAL();
}
/*-----------------------------------------------------------*/
/*
* Hardware initialisation to generate the RTOS tick.
*/
static void prvSetupTimerInterrupt( void )
{
XTmrCtr xTimer;
const uint32_t ulCounterValue = configCPU_CLOCK_HZ / configTICK_RATE_HZ;
UBaseType_t uxMask;
/* The OPB timer1 is used to generate the tick. Use the provided library
* functions to enable the timer and set the tick frequency. */
XTmrCtr_mDisable( XPAR_OPB_TIMER_1_BASEADDR, XPAR_OPB_TIMER_1_DEVICE_ID );
XTmrCtr_Initialize( &xTimer, XPAR_OPB_TIMER_1_DEVICE_ID );
XTmrCtr_mSetLoadReg( XPAR_OPB_TIMER_1_BASEADDR, portCOUNTER_0, ulCounterValue );
XTmrCtr_mSetControlStatusReg( XPAR_OPB_TIMER_1_BASEADDR, portCOUNTER_0, XTC_CSR_LOAD_MASK | XTC_CSR_INT_occurred_MASK );
/* Set the timer interrupt enable bit while maintaining the other bit
* states. */
uxMask = XIntc_In32( ( XPAR_OPB_INTC_0_BASEADDR + XIN_IER_OFFSET ) );
uxMask |= XPAR_OPB_TIMER_1_INTERRUPT_MASK;
XIntc_Out32( ( XPAR_OPB_INTC_0_BASEADDR + XIN_IER_OFFSET ), ( uxMask ) );
XTmrCtr_Start( &xTimer, XPAR_OPB_TIMER_1_DEVICE_ID );
XTmrCtr_mSetControlStatusReg( XPAR_OPB_TIMER_1_BASEADDR, portCOUNTER_0, XTC_CSR_ENABLE_TMR_MASK | XTC_CSR_ENABLE_INT_MASK | XTC_CSR_AUTO_RELOAD_MASK | XTC_CSR_DOWN_COUNT_MASK | XTC_CSR_INT_occurred_MASK );
XIntc_mAckIntr( XPAR_INTC_SINGLE_BASEADDR, 1 );
}
/*-----------------------------------------------------------*/
/*
* The interrupt handler placed in the interrupt vector when the scheduler is
* started. The task context has already been saved when this is called.
* This handler determines the interrupt source and calls the relevant
* peripheral handler.
*/
void vTaskISRHandler( void )
{
static uint32_t ulPending;
/* Which interrupts are pending? */
ulPending = XIntc_In32( ( XPAR_INTC_SINGLE_BASEADDR + XIN_IVR_OFFSET ) );
if( ulPending < XPAR_INTC_MAX_NUM_INTR_INPUTS )
{
static XIntc_VectorTableEntry * pxTablePtr;
static XIntc_Config * pxConfig;
static uint32_t ulInterruptMask;
ulInterruptMask = ( uint32_t ) 1 << ulPending;
/* Get the configuration data using the device ID */
pxConfig = &XIntc_ConfigTable[ ( uint32_t ) XPAR_INTC_SINGLE_DEVICE_ID ];
pxTablePtr = &( pxConfig->HandlerTable[ ulPending ] );
if( pxConfig->AckBeforeService & ( ulInterruptMask ) )
{
XIntc_mAckIntr( pxConfig->BaseAddress, ulInterruptMask );
pxTablePtr->Handler( pxTablePtr->CallBackRef );
}
else
{
pxTablePtr->Handler( pxTablePtr->CallBackRef );
XIntc_mAckIntr( pxConfig->BaseAddress, ulInterruptMask );
}
}
}
/*-----------------------------------------------------------*/
/*
* Handler for the timer interrupt.
*/
void vTickISR( void * pvBaseAddress )
{
uint32_t ulCSR;
/* Increment the RTOS tick - this might cause a task to unblock. */
if( xTaskIncrementTick() != pdFALSE )
{
vTaskSwitchContext();
}
/* Clear the timer interrupt */
ulCSR = XTmrCtr_mGetControlStatusReg( XPAR_OPB_TIMER_1_BASEADDR, 0 );
XTmrCtr_mSetControlStatusReg( XPAR_OPB_TIMER_1_BASEADDR, portCOUNTER_0, ulCSR );
}
/*-----------------------------------------------------------*/
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