mirror of
https://github.com/FreeRTOS/FreeRTOS-Kernel.git
synced 2025-04-20 05:21:59 -04:00
274 lines
9.8 KiB
C
274 lines
9.8 KiB
C
/*
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* FreeRTOS Kernel V10.1.1
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* Copyright (C) 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of
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* this software and associated documentation files (the "Software"), to deal in
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* the Software without restriction, including without limitation the rights to
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* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
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* the Software, and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
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* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
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* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*
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* http://www.FreeRTOS.org
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* http://aws.amazon.com/freertos
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*
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* 1 tab == 4 spaces!
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*/
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/*-----------------------------------------------------------
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* Implementation of functions defined in portable.h for the RISC-V RV32 port.
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*----------------------------------------------------------*/
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/* Scheduler includes. */
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#include "FreeRTOS.h"
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#include "task.h"
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#include "portmacro.h"
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#ifdef configISR_STACK_SIZE
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/* The stack used by interrupt service routines. */
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static __attribute__ ((aligned(16))) StackType_t xISRStack[ configISR_STACK_SIZE ] = { 0 };
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const StackType_t * const xISRStackTop = &( xISRStack[ ( configISR_STACK_SIZE & ~portBYTE_ALIGNMENT_MASK ) - 1 ] );
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#else
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#warning What should _sp be named?
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extern const uint32_t _sp[];
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const uint32_t xISRStackTop = ( uint32_t ) _sp;
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#endif
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/*
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* Setup the timer to generate the tick interrupts. The implementation in this
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* file is weak to allow application writers to change the timer used to
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* generate the tick interrupt.
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*/
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void vPortSetupTimerInterrupt( void ) __attribute__(( weak ));
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/*
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* Used to catch tasks that attempt to return from their implementing function.
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*/
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static void prvTaskExitError( void );
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/*-----------------------------------------------------------*/
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/* Used to program the machine timer compare register. */
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uint64_t ullNextTime = 0ULL;
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const uint64_t *pullNextTime = &ullNextTime;
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const uint32_t ulTimerIncrementsForOneTick = ( uint32_t ) ( configCPU_CLOCK_HZ / configTICK_RATE_HZ ); /* Assumes increment won't go over 32-bits. */
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volatile uint64_t * const pullMachineTimerCompareRegister = ( volatile uint64_t * const ) ( configCLINT_BASE_ADDRESS + 0x4000 );
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/* Set configCHECK_FOR_STACK_OVERFLOW to 3 to add ISR stack checking to task
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stack checking. A problem in the ISR stack will trigger an assert, not call the
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stack overflow hook function (because the stack overflow hook is specific to a
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task stack, not the ISR stack). */
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#if( configCHECK_FOR_STACK_OVERFLOW > 2 )
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#warning This path not tested, or even compiled yet.
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/* Don't use 0xa5 as the stack fill bytes as that is used by the kernerl for
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the task stacks, and so will legitimately appear in many positions within
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the ISR stack. */
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#define portISR_STACK_FILL_BYTE 0xee
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static const uint8_t ucExpectedStackBytes[] = {
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portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, \
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portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, \
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portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, \
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portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, \
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portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE }; \
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#define portCHECK_ISR_STACK() configASSERT( ( memcmp( ( void * ) xISRStack, ( void * ) ucExpectedStackBytes, sizeof( ucExpectedStackBytes ) ) == 0 ) )
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#else
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/* Define the function away. */
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#define portCHECK_ISR_STACK()
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#endif /* configCHECK_FOR_STACK_OVERFLOW > 2 */
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/*-----------------------------------------------------------*/
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void prvTaskExitError( void )
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{
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volatile uint32_t ulx = 0;
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/* A function that implements a task must not exit or attempt to return to
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its caller as there is nothing to return to. If a task wants to exit it
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should instead call vTaskDelete( NULL ).
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Artificially force an assert() to be triggered if configASSERT() is
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defined, then stop here so application writers can catch the error. */
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configASSERT( ulx == ~0UL );
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portDISABLE_INTERRUPTS();
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for( ;; );
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}
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/*-----------------------------------------------------------*/
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/*
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* See header file for description.
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*/
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StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )
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{
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uint32_t mstatus;
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const uint32_t ulMPIE_Bit = 0x80, ulMPP_Bits = 0x1800;
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/*
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X1 to X31 integer registers for the 'I' profile, X1 to X15 for the 'E' profile.
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Register ABI Name Description Saver
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x0 zero Hard-wired zero -
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x1 ra Return address Caller
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x2 sp Stack pointer Callee
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x3 gp Global pointer -
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x4 tp Thread pointer -
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x5-7 t0-2 Temporaries Caller
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x8 s0/fp Saved register/Frame pointer Callee
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x9 s1 Saved register Callee
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x10-11 a0-1 Function Arguments/return values Caller
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x12-17 a2-7 Function arguments Caller
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x18-27 s2-11 Saved registers Callee
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x28-31 t3-6 Temporaries Caller
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*/
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/* Start task with interrupt enabled. */
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__asm volatile ("csrr %0, mstatus" : "=r"(mstatus));
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mstatus |= ulMPIE_Bit | ulMPP_Bits;
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pxTopOfStack--;
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*pxTopOfStack = mstatus;
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/* Numbers correspond to the x register number. */
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 31;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 30;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 29;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 28;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 27;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 26;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 25;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 24;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 23;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 22;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 21;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 20;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 19;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 18;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 17;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 16;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 15;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 14;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 13;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 12;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 11;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) pvParameters;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 9;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 8;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 7;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 6;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) 5;
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pxTopOfStack--;
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// *pxTopOfStack = ( StackType_t ) 4; /* Thread pointer. */
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// pxTopOfStack--;
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// *pxTopOfStack = ( StackType_t ) 3; /* Global pointer. */
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// pxTopOfStack--;
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// *pxTopOfStack = ( StackType_t ) 2; /* Stack pointer. */
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// pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) prvTaskExitError;
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pxTopOfStack--;
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*pxTopOfStack = ( StackType_t ) pxCode;
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return pxTopOfStack;
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}
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/*-----------------------------------------------------------*/
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void vPortSetupTimerInterrupt( void )
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{
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uint32_t ulCurrentTimeHigh, ulCurrentTimeLow;
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volatile uint32_t * const pulTimeHigh = ( volatile uint32_t * const ) ( configCLINT_BASE_ADDRESS + 0xBFFC );
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volatile uint32_t * const pulTimeLow = ( volatile uint32_t * const ) ( configCLINT_BASE_ADDRESS + 0xBFF8 );
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do
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{
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ulCurrentTimeHigh = *pulTimeHigh;
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ulCurrentTimeLow = *pulTimeLow;
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} while( ulCurrentTimeHigh != *pulTimeHigh );
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ullNextTime = ( uint64_t ) ulCurrentTimeHigh;
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ullNextTime <<= 32ULL;
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ullNextTime |= ( uint64_t ) ulCurrentTimeLow;
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ullNextTime += ( uint64_t ) ulTimerIncrementsForOneTick;
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*pullMachineTimerCompareRegister = ullNextTime;
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/* Prepare the time to use after the next tick interrupt. */
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ullNextTime += ( uint64_t ) ulTimerIncrementsForOneTick;
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/* Enable timer interrupt. */
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__asm volatile( "csrs mie, %0" :: "r"(0x80) ); /* 1<<7 for timer interrupt. */
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}
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/*-----------------------------------------------------------*/
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BaseType_t xPortStartScheduler( void )
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{
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extern void xPortStartFirstTask( void );
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#if( configASSERT_DEFINED == 1 )
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{
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volatile uint32_t mtvec = 0;
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/* Check the least significant two bits of mtvec are 00 - indicating
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single vector mode. */
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__asm volatile( "csrr %0, mtvec" : "=r"( mtvec ) );
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configASSERT( ( mtvec & 0x03UL ) == 0 );
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/* Check alignment of the interrupt stack - which is the same as the
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stack that was being used by main() prior to the scheduler being
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started. */
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configASSERT( ( xISRStackTop & portBYTE_ALIGNMENT_MASK ) == 0 );
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}
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#endif
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vPortSetupTimerInterrupt();
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xPortStartFirstTask();
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/* Should not get here as after calling xPortStartFirstTask() only tasks
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should be executing. */
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return pdFAIL;
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}
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/*-----------------------------------------------------------*/
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void vPortEndScheduler( void )
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{
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/* Not implemented. */
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for( ;; );
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}
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