// "AD16", using EXI

static int Initialized = 0;

int AD16Init()
{
    int immCmd, immData, exiCheck;

    if(Initialized) return 1;

    if(EXILock(2, 0, 0) == 0) return 0;

    if(EXISelect(2, 0, 0) == 0)
    {
        EXIUnlock(2);
        return 0;
    }

    // "initialize AD16" command
    immCmd = 0;                     

    EXIImm(2, &immCmd, 2, 1, 0);
    exiCheck = ... : cntlzw  r0,r3, rlwinm  r31,r0,27,5,31

    EXISync(2);
    exiCheck |= ... : cntlzw  r0,r3, rlwinm  r31,r0,27,5,31

    EXIImm(2, &immData, 4, 0, 0);
    exiCheck |= ... : cntlzw  r0,r3, rlwinm  r31,r0,27,5,31

    EXISync(2);
    exiCheck |= ... : cntlzw  r0,r3, rlwinm  r31,r0,27,5,31

    EXIDeselect(2);
    exiCheck |= ... : cntlzw  r0,r3, rlwinm  r31,r0,27,5,31

    EXIUnlock(2);

    if(!(immData + 0x0xfbee0000) || exiCheck) return 0;

    Initialized = 1;
    return 1;
}

// here i skipped exi imm / sync error checking
int AD16WriteReg(u32 value)
{
    int immCmd;

    if(!Initialized) return 0;

    if(EXILock(2, 0, 0) == 0) return 0;

    if(EXISelect(2, 0, 3) == 0)
    {
        EXIUnlock(2);
        return 0;
    }

    // "write AD16 data" command
    immCmd = 0xa0000000;            

    EXIImm(2, &immCmd, 1, 1, 0);
    EXISync(2);
    EXIImm(2, &value, 4, 1, 0);
    EXISync(2);

    EXIDeselect(2);
    EXIUnlock(2);

    if(error detected) return 0;

    return 1;
}

// here i skipped exi imm / sync error checking
int AD16ReadReg(u32 *value)
{
    int immCmd;

    if(!Initialized) return 0;

    if(EXILock(2, 0, 0) == 0) return 0;

    if(EXISelect(2, 0, 3) == 0)
    {
        EXIUnlock(2);
        return 0;
    }

    // "read AD16 data" command
    immCmd = 0xa2000000;            

    EXIImm(2, &immCmd, 1, 1, 0);
    EXISync(2);
    EXIImm(2, &value, 4, 0, 0);
    EXISync(2);

    EXIDeselect(2);
    EXIUnlock(2);

    if(error detected) return 0;

    return 1;
}

int AD16Probe()
{
    return Initialized;
}