| /* |
| * FreeRTOS SMP Kernel V202110.00 |
| * 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. |
| * |
| * https://www.FreeRTOS.org |
| * https://github.com/FreeRTOS |
| * |
| * 1 tab == 4 spaces! |
| */ |
| |
| /*----------------------------------------------------------- |
| * Implementation of functions defined in portable.h for the RISC-V RV32 port. |
| *----------------------------------------------------------*/ |
| |
| /* Scheduler includes. */ |
| #include "FreeRTOS.h" |
| #include "task.h" |
| #include "portmacro.h" |
| |
| /* Standard includes. */ |
| #include "string.h" |
| |
| #ifdef configCLINT_BASE_ADDRESS |
| #warning The configCLINT_BASE_ADDRESS constant has been deprecated. configMTIME_BASE_ADDRESS and configMTIMECMP_BASE_ADDRESS are currently being derived from the (possibly 0) configCLINT_BASE_ADDRESS setting. Please update to define configMTIME_BASE_ADDRESS and configMTIMECMP_BASE_ADDRESS dirctly in place of configCLINT_BASE_ADDRESS. See https://www.FreeRTOS.org/Using-FreeRTOS-on-RISC-V.html |
| #endif |
| |
| #ifndef configMTIME_BASE_ADDRESS |
| #warning configMTIME_BASE_ADDRESS must be defined in FreeRTOSConfig.h. If the target chip includes a memory-mapped mtime register then set configMTIME_BASE_ADDRESS to the mapped address. Otherwise set configMTIME_BASE_ADDRESS to 0. See https://www.FreeRTOS.org/Using-FreeRTOS-on-RISC-V.html |
| #endif |
| |
| #ifndef configMTIMECMP_BASE_ADDRESS |
| #warning configMTIMECMP_BASE_ADDRESS must be defined in FreeRTOSConfig.h. If the target chip includes a memory-mapped mtimecmp register then set configMTIMECMP_BASE_ADDRESS to the mapped address. Otherwise set configMTIMECMP_BASE_ADDRESS to 0. See https://www.FreeRTOS.org/Using-FreeRTOS-on-RISC-V.html |
| #endif |
| |
| /* Let the user override the pre-loading of the initial LR with the address of |
| prvTaskExitError() in case it messes up unwinding of the stack in the |
| debugger. */ |
| #ifdef configTASK_RETURN_ADDRESS |
| #define portTASK_RETURN_ADDRESS configTASK_RETURN_ADDRESS |
| #else |
| #define portTASK_RETURN_ADDRESS prvTaskExitError |
| #endif |
| |
| /* The stack used by interrupt service routines. Set configISR_STACK_SIZE_WORDS |
| to use a statically allocated array as the interrupt stack. Alternative leave |
| configISR_STACK_SIZE_WORDS undefined and update the linker script so that a |
| linker variable names __freertos_irq_stack_top has the same value as the top |
| of the stack used by main. Using the linker script method will repurpose the |
| stack that was used by main before the scheduler was started for use as the |
| interrupt stack after the scheduler has started. */ |
| #ifdef configISR_STACK_SIZE_WORDS |
| static __attribute__ ((aligned(16))) StackType_t xISRStack[ configISR_STACK_SIZE_WORDS ] = { 0 }; |
| const StackType_t xISRStackTop = ( StackType_t ) &( xISRStack[ configISR_STACK_SIZE_WORDS & ~portBYTE_ALIGNMENT_MASK ] ); |
| |
| /* Don't use 0xa5 as the stack fill bytes as that is used by the kernerl for |
| the task stacks, and so will legitimately appear in many positions within |
| the ISR stack. */ |
| #define portISR_STACK_FILL_BYTE 0xee |
| #else |
| extern const uint32_t __freertos_irq_stack_top[]; |
| const StackType_t xISRStackTop = ( StackType_t ) __freertos_irq_stack_top; |
| #endif |
| |
| /* |
| * Setup the timer to generate the tick interrupts. The implementation in this |
| * file is weak to allow application writers to change the timer used to |
| * generate the tick interrupt. |
| */ |
| void vPortSetupTimerInterrupt( void ) __attribute__(( weak )); |
| |
| /*-----------------------------------------------------------*/ |
| |
| /* Used to program the machine timer compare register. */ |
| uint64_t ullNextTime = 0ULL; |
| const uint64_t *pullNextTime = &ullNextTime; |
| const size_t uxTimerIncrementsForOneTick = ( size_t ) ( ( configCPU_CLOCK_HZ ) / ( configTICK_RATE_HZ ) ); /* Assumes increment won't go over 32-bits. */ |
| uint32_t const ullMachineTimerCompareRegisterBase = configMTIMECMP_BASE_ADDRESS; |
| volatile uint64_t * pullMachineTimerCompareRegister = NULL; |
| |
| /* Set configCHECK_FOR_STACK_OVERFLOW to 3 to add ISR stack checking to task |
| stack checking. A problem in the ISR stack will trigger an assert, not call the |
| stack overflow hook function (because the stack overflow hook is specific to a |
| task stack, not the ISR stack). */ |
| #if defined( configISR_STACK_SIZE_WORDS ) && ( configCHECK_FOR_STACK_OVERFLOW > 2 ) |
| #warning This path not tested, or even compiled yet. |
| |
| static const uint8_t ucExpectedStackBytes[] = { |
| portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, \ |
| portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, \ |
| portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, \ |
| portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, \ |
| portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE, portISR_STACK_FILL_BYTE }; \ |
| |
| #define portCHECK_ISR_STACK() configASSERT( ( memcmp( ( void * ) xISRStack, ( void * ) ucExpectedStackBytes, sizeof( ucExpectedStackBytes ) ) == 0 ) ) |
| #else |
| /* Define the function away. */ |
| #define portCHECK_ISR_STACK() |
| #endif /* configCHECK_FOR_STACK_OVERFLOW > 2 */ |
| |
| /*-----------------------------------------------------------*/ |
| |
| #if( configMTIME_BASE_ADDRESS != 0 ) && ( configMTIMECMP_BASE_ADDRESS != 0 ) |
| |
| void vPortSetupTimerInterrupt( void ) |
| { |
| uint32_t ulCurrentTimeHigh, ulCurrentTimeLow; |
| volatile uint32_t * const pulTimeHigh = ( volatile uint32_t * const ) ( ( configMTIME_BASE_ADDRESS ) + 4UL ); /* 8-byte typer so high 32-bit word is 4 bytes up. */ |
| volatile uint32_t * const pulTimeLow = ( volatile uint32_t * const ) ( configMTIME_BASE_ADDRESS ); |
| volatile uint32_t ulHartId; |
| |
| __asm volatile( "csrr %0, mhartid" : "=r"( ulHartId ) ); |
| pullMachineTimerCompareRegister = ( volatile uint64_t * ) ( ullMachineTimerCompareRegisterBase + ( ulHartId * sizeof( uint64_t ) ) ); |
| |
| do |
| { |
| ulCurrentTimeHigh = *pulTimeHigh; |
| ulCurrentTimeLow = *pulTimeLow; |
| } while( ulCurrentTimeHigh != *pulTimeHigh ); |
| |
| ullNextTime = ( uint64_t ) ulCurrentTimeHigh; |
| ullNextTime <<= 32ULL; /* High 4-byte word is 32-bits up. */ |
| ullNextTime |= ( uint64_t ) ulCurrentTimeLow; |
| ullNextTime += ( uint64_t ) uxTimerIncrementsForOneTick; |
| *pullMachineTimerCompareRegister = ullNextTime; |
| |
| /* Prepare the time to use after the next tick interrupt. */ |
| ullNextTime += ( uint64_t ) uxTimerIncrementsForOneTick; |
| } |
| |
| #endif /* ( configMTIME_BASE_ADDRESS != 0 ) && ( configMTIME_BASE_ADDRESS != 0 ) */ |
| /*-----------------------------------------------------------*/ |
| |
| BaseType_t xPortStartScheduler( void ) |
| { |
| extern void xPortStartFirstTask( void ); |
| |
| #if( configASSERT_DEFINED == 1 ) |
| { |
| volatile uint32_t mtvec = 0; |
| |
| /* Check the least significant two bits of mtvec are 00 - indicating |
| single vector mode. */ |
| __asm volatile( "csrr %0, mtvec" : "=r"( mtvec ) ); |
| configASSERT( ( mtvec & 0x03UL ) == 0 ); |
| |
| /* Check alignment of the interrupt stack - which is the same as the |
| stack that was being used by main() prior to the scheduler being |
| started. */ |
| configASSERT( ( xISRStackTop & portBYTE_ALIGNMENT_MASK ) == 0 ); |
| |
| #ifdef configISR_STACK_SIZE_WORDS |
| { |
| memset( ( void * ) xISRStack, portISR_STACK_FILL_BYTE, sizeof( xISRStack ) ); |
| } |
| #endif /* configISR_STACK_SIZE_WORDS */ |
| } |
| #endif /* configASSERT_DEFINED */ |
| |
| /* If there is a CLINT then it is ok to use the default implementation |
| in this file, otherwise vPortSetupTimerInterrupt() must be implemented to |
| configure whichever clock is to be used to generate the tick interrupt. */ |
| vPortSetupTimerInterrupt(); |
| |
| #if( ( configMTIME_BASE_ADDRESS != 0 ) && ( configMTIMECMP_BASE_ADDRESS != 0 ) ) |
| { |
| /* Enable mtime and external interrupts. 1<<7 for timer interrupt, 1<<11 |
| for external interrupt. _RB_ What happens here when mtime is not present as |
| with pulpino? */ |
| __asm volatile( "csrs mie, %0" :: "r"(0x880) ); |
| } |
| #else |
| { |
| /* Enable external interrupts. */ |
| __asm volatile( "csrs mie, %0" :: "r"(0x800) ); |
| } |
| #endif /* ( configMTIME_BASE_ADDRESS != 0 ) && ( configMTIMECMP_BASE_ADDRESS != 0 ) */ |
| |
| xPortStartFirstTask(); |
| |
| /* Should not get here as after calling xPortStartFirstTask() only tasks |
| should be executing. */ |
| return pdFAIL; |
| } |
| /*-----------------------------------------------------------*/ |
| |
| void vPortEndScheduler( void ) |
| { |
| /* Not implemented. */ |
| for( ;; ); |
| } |
| |
| |
| |
| |
| |