ACPI causes page fault/panic upon reboot

Peter Schultz pmes at bis.midco.net
Wed Dec 31 06:12:33 PST 2003


Dan Hulme wrote:
> Disabling ACPI fixes the problem.  The problem appears to be in  dc0, 
> however.  See my other reply for details.
>

You might be able to use ACPI, run this command:

`acpidump -t -d > your.asl'

In your.asl, change if statements that compare the value of _OS from 
"Windows" to "FreeBSD".  For example*:

If (MCTH (\_OS, "Microsoft Windows NT"))
{
     Return (PIC1)
}
Else
{
     Return (PIC0)
}

Overridden for use with FreeBSD:
If (MCTH (\_OS, "FreeBSD"))
{
     Return (PIC1)
}
Else
{
     Return (PIC0)
}

After you customize your.asl, you'll want to compile** it, run:

`iasl -f your.asl'

DSDT.aml is the default output filename for the above command.  It's 
machine code you can offer to ACPI instead of using the DSDT provided 
with your motherboard.  You do this by editing /boot/loader.conf, add:

acpi_dsdt_load="YES"
acpi_dsdt_name="/boot/DSDT.aml"

Remember to move DSDT.aml to the /boot directory.  That's what I've done 
to get ACPI working back to how it was in the past.

HTH,
Pete...

* From my OEM ASL, a partnership with Microsoft?

** We're forcing compilation because it seems most OEM ASLs are buggy.


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