Warn when unsupported interrupt is enabled

[tikonen]

Description

QEMU should warn user when code tries to enable STM32 TIM2 interrupt. Currently this is silently ignored as the feature is not supported.

Steps to Reproduce

1. Enable STM32 TIM2 interrupt

Expected behaviour:

As TIM2 is not currently supported, QEMU should warn user in the console for using a unsupported feature.

Actual behaviour:

QEMU silently ignores the interrupt enable.

Versions

GNU ARM Eclipse 64-bits QEMU emulator version 2.8.0 (v2.8.0-646-g2c99a25-dirty)

Code used to enable interrupts:

#include <stdio.h>

#include "stm32f4xx.h"
#include "stm32f4_discovery.h"

extern void initialise_monitor_handles(void);

static TIM_HandleTypeDef sTimerInstance = {
    .Instance = TIM2
};

#define timerINTERRUPT_FREQUENCY        ( ( unsigned short ) 500 )

void InitTimer()
{
    __HAL_RCC_TIM2_CLK_ENABLE();

    sTimerInstance.Init.Prescaler = 1;
    sTimerInstance.Init.CounterMode = TIM_COUNTERMODE_UP;
    sTimerInstance.Init.Period = 16000000 / timerINTERRUPT_FREQUENCY;
    sTimerInstance.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
    sTimerInstance.Init.RepetitionCounter = 0;
    HAL_TIM_Base_Init(&sTimerInstance);

    __HAL_TIM_CLEAR_FLAG(&sTimerInstance, TIM_SR_UIF);

    HAL_TIM_Base_Start(&sTimerInstance);
    HAL_TIM_Base_Start_IT(&sTimerInstance);
}

// never gets called
void TIM2_IRQHandler()
{
    HAL_TIM_IRQHandler(&sTimerInstance);
}

void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
    // TODO 
}

int main(void)
{
    initialise_monitor_handles(); // semihosting, required for prints to work

    puts("main() - enter");

    HAL_Init();
    InitTimer();
    HAL_NVIC_SetPriority(TIM2_IRQn, 1, 1);
    HAL_NVIC_EnableIRQ(TIM2_IRQn);

    // dummy main loop
    for(;;) {
    }

    return 0;
}

[ilg-ul]

QEMU silently ignores the interrupt enable.

in fact, except the SysTick, none of the other timers are implemented.

@BrendanSimon plans to contribute support for TIM*, probably the next release will include support for them.

[ilg-ul]

we'll keep it open, hopefully in a future version it'll be fixed.