#include "FreeRTOS.h"
#include "task.h"

#include "ch32v30x.h"
#include "system_ch32v30x.h"

void SysTick_Handler(void) __attribute__((interrupt()));
void Ecall_M_Mode_Handler(void) __attribute__((interrupt()));

extern void freertos_risc_v_mtimer_interrupt_handler(void);

/**
 * Notes on FreeRTOS:
 * Current FreeRTOS supports both vectored and Non-Vectored exception model,
 * handled in portASM.h. WCH, however, has an unique exception model which
 * vectors both exceptions and interrupts to a fixed vector table, making trap handler
 * useless while handling ECALL exceptions, since they have their own entry point in IVT.
 */

/**
 * @brief Initialize SysTick interrupt.
 * 
 */
void vPortSetupTimerInterrupt(void) {
    /* Configure SysTick and interrupts. */
    SysTick->SR = 0UL;
    SysTick->CTLR = 0UL;
    SysTick->CNT = 0UL;

    NVIC_EnableIRQ(SysTicK_IRQn);

    SysTick->CMP = (uint64_t)((SystemCoreClock / configTICK_RATE_HZ) - 1);
    SysTick->CTLR = 0x1E; /* COUNTDOWN | AUTO RELOAD | HCLK | INT */
    SysTick->CTLR |= 0x20; /* INIT */

    SysTick->CTLR |= 0x01; /* EN */
}