Read/Write Once bits set on boot

Posted Jan 20, 2010 13:50 UTC (Wed) by kDawg (guest, #63114)
Parent article: Writing an ACPI driver - an introduction

I have a question that's slightly off topic. When trying to manipulate bits that are R/WO is it possible to modify them via ACPI? Or do they need to be set in BIOS. If so then would it be possible to modify BIOS to change these bits?

More specifically would it be possible to modify ICH10's PxCMDPort [5:0] Command Register (D31:F2) bit #18? For reference see Intel's ICH10 spec. page 553. It is set to 1 whereas I believe it's supposed to be 0. Since it's R/WO then I don't believe it's possible to modify the DSDT to enable this function.

Thanks, your response would be greatly appreciated.