[Devel] Question about ACPICA, QNX and making beeps

[Devel] Question about ACPICA, QNX and making beeps

[Devin Steffler]

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Hello,

I am using ACPICA to read battery information in QNX. That part is working
great so far. However, now some code that is being used to make beeps via
the PC speaker stopped working.

Strangely, this code stops working on a few devices only after ACPICA runs.
It works fine if I don't start ACPICA. The code is using I/O ports 0x43,
0x42, and 0x61 to generate beeps. This seems to be an industry standard way
to make beeps on x86 based PCs using a Programmable Interval Timer (PIT).

What could my ACPICA be doing (or failing to do) that could cause the beeps
to stop working with the code below? Is the PIT being disabled somehow? I
guess I'll need to learn more about the PIT and how to check its status to
see if it's being disabled after ACPICA runs.

Here's example code for QNX to generate a beep using the PC speaker:
// -----------------------------------------------
#include <sys/neutrino.h>
#include <hw/inout.h>
#include <unistd.h>

int main(void) {
    ThreadCtl( _NTO_TCTL_IO, 0 ); // get I/O permissions

    // start a beep
    int freq = 1000;
    int scale = 1193046 / freq;
    out8(0x43, 0xb6);
    out8(0x42, scale & 0xff);
    out8(0x42, scale >> 8);
    out8(0x61, in8(0x61) | 3);

    // let the beep play for a second
    delay(1000);

    // stop the beep
    out8(0x61, in8(0x61) & ~3);

    return 0;
}
// -----------------------------------------------

Thanks,
Devin

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