On computers with ACPI ( Advanced Configuration & Power Interface ) support (WinXP) i nave a BIG problem with serial ports read-write.

For example, I read COM1 port registers:

03f8 - have value ffh
03f9 - have value ffh
03fa - have value ffh
03fb - have value ffh
03fc - have value ffh
03fd - have value ffh
03fe - have value ffh
03ff - have value ffh

It's because UART chip power is off (sleeping) by ACPI in WinXP.

How i can switch Power On (wake up) UART chip with ASM from Ring3 (inteface program) or from Ring0 Kernel Mode Driver ?

PLEASE HELP ME ANYBODY !!! ... :(
I dont understand how i can do it about 3 days.. :((
Posted on 2003-10-23 07:11:51 by Poly
Posted on 2003-10-23 07:29:05 by Hiroshimator