On Thu, 14 Mar 2002, Martin Wilck wrote:
>
> Hello,
>
> the BIOS on our machines (Phoenix) uses IO-port 0x80 for storing
> POST codes, not only during sytem startup, but also for messages
> generated during SMM (system management mode) operation.
> I have been told other BIOSs do the same.
>
> Unfortunately we can't read this information because Linux uses
> port 80 as "dummy" port for delay operations. (outb_p and friends,
> actually there seem to be a more hard-coded references to port
> 0x80 in the code).
>
> It seems this problem was always there, just nobody took notice of it yet
> (at least in our company). Sometimes people wondered about the weird POST
> codes displayed in the LCD panel, but who cares once the machine is up...
>
> Would it be too outrageous to ask that this port number be changed, or
> made configurable?
>
> Martin
This is a 'N' year-old question. Do you know of a port that is
guaranteed to exist on the Intel/PC/AT class machine? If so, submit
a patch. I proposed using 0x19h (DMA scratch register) several
years ago, but it was shot down for some reason. Then I proposed
0x42 (PIT Misc register), that too was declared off-limits. So
I suggested that the outb to 0x80 be changed to an inp, saving
%eax on the stack first. That too was shot down. So, you try
something... and good luck.
Cheers,
Dick Johnson
Penguin : Linux version 2.4.18 on an i686 machine (797.90 BogoMips).
Windows-2000/Professional isn't.
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This archive was generated by hypermail 2b29 : Fri Mar 15 2002 - 22:00:18 EST