ninty's irq functions

irqs.c

#include "irqs.h"

u32 irq_ack(u32 irqs) {
    u16 ime = REG_IME;
    REG_IME = 0;

    u32 ifs = REG_IF;
    REG_IF = irqs;

    REG_IME = ime;

    return ifs;
}

u32 irq_disable(u32 irqs) {
    u16 ime = REG_IME;
    REG_IME = 0;

    u32 ies = REG_IE;
    REG_IE = ies & ~irqs;

    REG_IME = ime;

    return ies;
}

u32 irq_enable(u32 irqs) {
    u16 ime = REG_IME;
    REG_IME = 0;

    u32 ies = REG_IE;
    REG_IE = ies | irqs;

    REG_IME = ime;

    return ies;
}

u32 irq_restore(u32 irqs) {
    u16 ime = REG_IME;
    REG_IME = 0;

    u32 ies = REG_IE;
    REG_IE = irqs;

    REG_IME = ime;

    return ies;
}

irqs.h

#ifndef _IRQS_H
#define _IRQS_H

#define REG_IME (*(u16 *)0x4000208)
#define REG_IE (*(u32 *)0x4000210)
#define REG_IF (*(u32 *)0x4000214)

#endif