FreeRTOS-Kernel/FreeRTOS/Demo/RISC-V_RV32_QEMU_VIRT_GCC/main.c

/*
 * FreeRTOS V202212.00
 * 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
 *
 */


/******************************************************************************
 * See https://www.freertos.org/freertos-on-qemu-mps2-an385-model.html for
 * instructions.
 *
 * This project provides two demo applications.  A simple blinky style project,
 * and a more comprehensive test and demo application.  The
 * mainCREATE_SIMPLE_BLINKY_DEMO_ONLY constant, defined in this file, is used to
 * select between the two.  The simply blinky demo is implemented and described
 * in main_blinky.c.  The more comprehensive test and demo application is
 * implemented and described in main_full.c.
 *
 * This file implements the code that is not demo specific, including the
 * hardware setup and FreeRTOS hook functions.
 *
 * Running in QEMU:
 * Use the following commands to start the application running in a way that
 * enables the debugger to connect, omit the "-s -S" to run the project without
 * the debugger:
 *
 * qemu-system-riscv32 -machine virt -smp 1 -nographic -bios none -serial stdio -kernel [path-to]/RTOSDemo.elf -s -S
 */

/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"

/* Standard includes. */
#include <stdio.h>
#include <string.h>

/* This project provides two demo applications.  A simple blinky style demo
 * application, and a more comprehensive test and demo application.  The
 * mainCREATE_SIMPLE_BLINKY_DEMO_ONLY setting is used to select between the two.
 *
 * If mainCREATE_SIMPLE_BLINKY_DEMO_ONLY is 1 then the blinky demo will be built.
 * The blinky demo is implemented and described in main_blinky.c.
 *
 * If mainCREATE_SIMPLE_BLINKY_DEMO_ONLY is not 1 then the comprehensive test and
 * demo application will be built.  The comprehensive test and demo application is
 * implemented and described in main_full.c. */
#define mainCREATE_SIMPLE_BLINKY_DEMO_ONLY    0

/* Set to 1 to use direct mode and set to 0 to use vectored mode.
 * VECTOR MODE=Direct --> all traps into machine mode cause the pc to be set to the
 * vector base address (BASE) in the mtvec register.
 * VECTOR MODE=Vectored --> all synchronous exceptions into machine mode cause the
 * pc to be set to the BASE, whereas interrupts cause the pc to be set to the
 * address BASE plus four times the interrupt cause number.
 */
#define mainVECTOR_MODE_DIRECT                0

/* printf() output uses the UART.  These constants define the addresses of the
 * required UART registers. */
#define UART0_ADDRESS                         ( 0x40004000UL )
#define UART0_DATA                            ( *( ( ( volatile uint32_t * ) ( UART0_ADDRESS + 0UL ) ) ) )
#define UART0_STATE                           ( *( ( ( volatile uint32_t * ) ( UART0_ADDRESS + 4UL ) ) ) )
#define UART0_CTRL                            ( *( ( ( volatile uint32_t * ) ( UART0_ADDRESS + 8UL ) ) ) )
#define UART0_BAUDDIV                         ( *( ( ( volatile uint32_t * ) ( UART0_ADDRESS + 16UL ) ) ) )
#define TX_BUFFER_MASK                        ( 1UL )

/* Registers used to initialise the PLIC. */
#define mainPLIC_PENDING_0                    ( *( ( volatile uint32_t * ) 0x0C001000UL ) )
#define mainPLIC_PENDING_1                    ( *( ( volatile uint32_t * ) 0x0C001004UL ) )
#define mainPLIC_ENABLE_0                     ( *( ( volatile uint32_t * ) 0x0C002000UL ) )
#define mainPLIC_ENABLE_1                     ( *( ( volatile uint32_t * ) 0x0C002004UL ) )

extern void freertos_risc_v_trap_handler( void );
extern void freertos_vector_table( void );

/*
 * main_blinky() is used when mainCREATE_SIMPLE_BLINKY_DEMO_ONLY is set to 1.
 * main_full() is used when mainCREATE_SIMPLE_BLINKY_DEMO_ONLY is set to 0.
 */
extern void main_blinky( void );
extern void main_full( void );

/*
 * Only the comprehensive demo uses application hook (callback) functions.  See
 * https://www.FreeRTOS.org/a00016.html for more information.
 */
void vFullDemoTickHookFunction( void );
void vFullDemoIdleFunction( void );

/*-----------------------------------------------------------*/

void main( void )
{
    /* See https://www.freertos.org/freertos-on-qemu-mps2-an385-model.html for
     * instructions. */

    #if ( mainVECTOR_MODE_DIRECT == 1 )
    {
        __asm__ volatile ( "csrw mtvec, %0" : : "r" ( freertos_risc_v_trap_handler ) );
    }
    #else
    {
        __asm__ volatile ( "csrw mtvec, %0" : : "r" ( ( uintptr_t ) freertos_vector_table | 0x1 ) );
    }
    #endif

    /* The mainCREATE_SIMPLE_BLINKY_DEMO_ONLY setting is described at the top
     * of this file. */
    #if ( mainCREATE_SIMPLE_BLINKY_DEMO_ONLY == 1 )
    {
        main_blinky();
    }
    #else
    {
        main_full();
    }
    #endif
}
/*-----------------------------------------------------------*/

void vApplicationMallocFailedHook( void )
{
    /* vApplicationMallocFailedHook() will only be called if
     * configUSE_MALLOC_FAILED_HOOK is set to 1 in FreeRTOSConfig.h.  It is a hook
     * function that will get called if a call to pvPortMalloc() fails.
     * pvPortMalloc() is called internally by the kernel whenever a task, queue,
     * timer or semaphore is created using the dynamic allocation (as opposed to
     * static allocation) option.  It is also called by various parts of the
     * demo application.  If heap_1.c, heap_2.c or heap_4.c is being used, then the
     * size of the	heap available to pvPortMalloc() is defined by
     * configTOTAL_HEAP_SIZE in FreeRTOSConfig.h, and the xPortGetFreeHeapSize()
     * API function can be used to query the size of free heap space that remains
     * (although it does not provide information on how the remaining heap might be
     * fragmented).  See http://www.freertos.org/a00111.html for more
     * information. */
    printf( "\r\n\r\nMalloc failed\r\n" );
    portDISABLE_INTERRUPTS();

    for( ; ; )
    {
    }
}
/*-----------------------------------------------------------*/

void vApplicationIdleHook( void )
{
    /* vApplicationIdleHook() will only be called if configUSE_IDLE_HOOK is set
     * to 1 in FreeRTOSConfig.h.  It will be called on each iteration of the idle
     * task.  It is essential that code added to this hook function never attempts
     * to block in any way (for example, call xQueueReceive() with a block time
     * specified, or call vTaskDelay()).  If application tasks make use of the
     * vTaskDelete() API function to delete themselves then it is also important
     * that vApplicationIdleHook() is permitted to return to its calling function,
     * because it is the responsibility of the idle task to clean up memory
     * allocated by the kernel to any task that has since deleted itself. */
}
/*-----------------------------------------------------------*/

void vApplicationStackOverflowHook( TaskHandle_t pxTask,
                                    char * pcTaskName )
{
    ( void ) pcTaskName;
    ( void ) pxTask;

    /* Run time stack overflow checking is performed if
     * configCHECK_FOR_STACK_OVERFLOW is defined to 1 or 2.  This hook
     * function is called if a stack overflow is detected. */
    printf( "\r\n\r\nStack overflow in %s\r\n", pcTaskName );
    portDISABLE_INTERRUPTS();

    for( ; ; )
    {
    }
}
/*-----------------------------------------------------------*/

void vApplicationTickHook( void )
{
    /* This function will be called by each tick interrupt if
    * configUSE_TICK_HOOK is set to 1 in FreeRTOSConfig.h.  User code can be
    * added here, but the tick hook is called from an interrupt context, so
    * code must not attempt to block, and only the interrupt safe FreeRTOS API
    * functions can be used (those that end in FromISR()). */

    #if ( mainCREATE_SIMPLE_BLINKY_DEMO_ONLY != 1 )
    {
        extern void vFullDemoTickHookFunction( void );

        vFullDemoTickHookFunction();
    }
    #endif /* mainCREATE_SIMPLE_BLINKY_DEMO_ONLY */
}
/*-----------------------------------------------------------*/

void vApplicationDaemonTaskStartupHook( void )
{
    /* This function will be called once only, when the daemon task starts to
     * execute (sometimes called the timer task).  This is useful if the
     * application includes initialisation code that would benefit from executing
     * after the scheduler has been started. */
}
/*-----------------------------------------------------------*/

void vAssertCalled( const char * pcFileName,
                    uint32_t ulLine )
{
    volatile uint32_t ulSetToNonZeroInDebuggerToContinue = 0;

    /* Called if an assertion passed to configASSERT() fails.  See
     * http://www.freertos.org/a00110.html#configASSERT for more information. */

    printf( "ASSERT! Line %d, file %s\r\n", ( int ) ulLine, pcFileName );

    taskENTER_CRITICAL();
    {
        /* You can step out of this function to debug the assertion by using
         * the debugger to set ulSetToNonZeroInDebuggerToContinue to a non-zero
         * value. */
        while( ulSetToNonZeroInDebuggerToContinue == 0 )
        {
            __asm volatile ( "NOP" );
            __asm volatile ( "NOP" );
        }
    }
    taskEXIT_CRITICAL();
}
/*-----------------------------------------------------------*/

/* configUSE_STATIC_ALLOCATION is set to 1, so the application must provide an
 * implementation of vApplicationGetIdleTaskMemory() to provide the memory that is
 * used by the Idle task. */
void vApplicationGetIdleTaskMemory( StaticTask_t ** ppxIdleTaskTCBBuffer,
                                    StackType_t ** ppxIdleTaskStackBuffer,
                                    StackType_t * pulIdleTaskStackSize )
{
/* If the buffers to be provided to the Idle task are declared inside this
 * function then they must be declared static - otherwise they will be allocated on
 * the stack and so not exists after this function exits. */
    static StaticTask_t xIdleTaskTCB;
    static StackType_t uxIdleTaskStack[ configMINIMAL_STACK_SIZE ];

    /* Pass out a pointer to the StaticTask_t structure in which the Idle task's
     * state will be stored. */
    *ppxIdleTaskTCBBuffer = &xIdleTaskTCB;

    /* Pass out the array that will be used as the Idle task's stack. */
    *ppxIdleTaskStackBuffer = uxIdleTaskStack;

    /* Pass out the size of the array pointed to by *ppxIdleTaskStackBuffer.
     * Note that, as the array is necessarily of type StackType_t,
     * configMINIMAL_STACK_SIZE is specified in words, not bytes. */
    *pulIdleTaskStackSize = configMINIMAL_STACK_SIZE;
}
/*-----------------------------------------------------------*/

/* configUSE_STATIC_ALLOCATION and configUSE_TIMERS are both set to 1, so the
 * application must provide an implementation of vApplicationGetTimerTaskMemory()
 * to provide the memory that is used by the Timer service task. */
void vApplicationGetTimerTaskMemory( StaticTask_t ** ppxTimerTaskTCBBuffer,
                                     StackType_t ** ppxTimerTaskStackBuffer,
                                     uint32_t * pulTimerTaskStackSize )
{
/* If the buffers to be provided to the Timer task are declared inside this
 * function then they must be declared static - otherwise they will be allocated on
 * the stack and so not exists after this function exits. */
    static StaticTask_t xTimerTaskTCB;
    static StackType_t uxTimerTaskStack[ configTIMER_TASK_STACK_DEPTH ];

    /* Pass out a pointer to the StaticTask_t structure in which the Timer
     * task's state will be stored. */
    *ppxTimerTaskTCBBuffer = &xTimerTaskTCB;

    /* Pass out the array that will be used as the Timer task's stack. */
    *ppxTimerTaskStackBuffer = uxTimerTaskStack;

    /* Pass out the size of the array pointed to by *ppxTimerTaskStackBuffer.
     * Note that, as the array is necessarily of type StackType_t,
     * configMINIMAL_STACK_SIZE is specified in words, not bytes. */
    *pulTimerTaskStackSize = configTIMER_TASK_STACK_DEPTH;
}
/*-----------------------------------------------------------*/

int __write( int iFile,
             char * pcString,
             int iStringLength )
{
    int iNextChar;

    /* Avoid compiler warnings about unused parameters. */
    ( void ) iFile;

    /* Output the formatted string to the UART. */
    for( iNextChar = 0; iNextChar < iStringLength; iNextChar++ )
    {
        while( ( UART0_STATE & TX_BUFFER_MASK ) != 0 )
        {
        }

        UART0_DATA = *pcString;
        pcString++;
    }

    return iStringLength;
}
/*-----------------------------------------------------------*/

void * malloc( size_t size )
{
    ( void ) size;

    /* This project uses heap_4 so doesn't set up a heap for use by the C
     * library - but something is calling the C library malloc().  See
     * https://freertos.org/a00111.html for more information. */
    printf( "\r\n\r\nUnexpected call to malloc() - should be using pvPortMalloc()\r\n" );
    portDISABLE_INTERRUPTS();

    for( ; ; )
    {
    }
}
/*-----------------------------------------------------------*/