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HAL

Hardware Abstraction Layer

Interrupts​

Handlers​

Registering interrupts can be done with the HAL through the following function:

int hal_registerInterruptHandler(uintptr_t int_number, hal_interrupt_handler_t handler, void *context);
  • int_number: The target interrupt number to use
  • handler: The handler to use
  • context: The context to pass to the handler

The interrupt handler is declared as:

typedef int (*hal_interrupt_handler_t)(void *context);
danger

Returning nonzero from an interrupt handler will cause IRQ_HANDLER_FAILED to be thrown.

You can unregister interrupt handlers using the following function:

void hal_unregisterInterruptHandler(uintptr_t int_no);

Check if a handler is in use with the following function:

int hal_interruptHandlerInUse(uintptr_t int_number);

Controlling interrupts on the CPU​

You can use the following functions to get/set the interrupt state:

void hal_setInterruptState(int state);
int hal_getInterruptState();

Possible values:

  • HAL_INTERRUPTS_ENABLED
  • HAL_INTERRUPTS_DISABLED

Power​

caution

To perform a safe shutdown, you should inform the kernel of the shutdown. See the example

Available HAL power states include:

  • HAL_POWER_REBOOT: Reboot the computer
  • HAL_POWER_SHUTDOWN: Shutdown the computer
  • HAL_POWER_HIBERNATE: Hibernate the computer

Prepare the computer to change to a power state with hal_changePowerState (note that kernel_prepareForPowerState does this for you)

void hal_prepareForPowerState(int state);

Set the power state with hal_setPowerState:

int hal_setPowerState(int state);

Power Example​

void shutdown() {
    kernel_prepareForPowerState(HAL_POWER_SHUTDOWN);
    hal_setPowerState(HAL_POWER_SHUTDOWN);
    __builtin_unreachable();
}