homebrew/inc/n64_util.inc

macro EnableInt() {
    // careful not to touch unrelated flags here
    mfc0    t0, CP0_Status
    addiu   at, r0, CP0_STATUS_IE
    or      t0, at
    mtc0    t0, CP0_Status
}

macro DisableInt() {
    // careful not to touch unrelated flags here
    mfc0    t0, CP0_Status
    addiu   at, r0, ~CP0_STATUS_IE
    and     t0, at
    mtc0    t0, CP0_Status
}

macro SetIntMask() {
    lli     t0, MI_INTR_MASK_ALL_SET
    lui     a0, MI_BASE
    sw      t0, MI_INTR_MASK(a0)
    // careful not to touch unrelated flags here
    mfc0    t1, CP0_Status
    lli     t0, CP0_STATUS_IM_ALL
    or      t1, t0
    mtc0    t1, CP0_Status
}

macro ClearIntMask() {
    lli     t0, MI_INTR_MASK_ALL_CLR
    lui     a0, MI_BASE
    sw      t0, MI_INTR_MASK(a0)
    // careful not to touch unrelated flags here
    mfc0    t1, CP0_Status
    lli     t0, CP0_STATUS_IM_ALL
    nor     t0, r0 // invert the mask (including upper halfword)
    and     t1, t0
    mtc0    t1, CP0_Status
}