[PLUG] help me understand this pin-level kernel-interface stuff

[Russell Senior]

>>>>> "Russell" == Russell Senior <russell at personaltelco.net> writes:

Jason> Call iopl(3) to set the I/O privilege level for your user space
Jason> process and call inl() directly?

Russell> Yeah, I tried that.  I'm moving to the theory that there is
Russell> something "wrong" with the board or the bios or the
Russell> documentation, because that isn't working.  I have a query in
Russell> to the designer/vendor asking about it.

Russell> Turns out the ports to control the LEDs don't seem to do
Russell> anything either.  I can send state to them, and read that
Russell> state back, but the LEDs don't change brightness.

Hmm.  Need help parsing this from lspci -vvv:

00:0f.0 ISA bridge: Advanced Micro Devices [AMD] CS5536 [Geode companion] ISA (rev 03)
        Subsystem: Advanced Micro Devices [AMD] CS5536 [Geode companion] ISA
        Control: I/O+ Mem- BusMaster- SpecCycle+ MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
        Status: Cap- 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
        Region 0: I/O ports at 6000 [size=8]
        Region 1: I/O ports at 6100 [size=256]
        Region 2: I/O ports at 6200 [size=64]
        Region 3: I/O ports at 1000 [size=32]
        Region 4: I/O ports at 9d00 [size=128]
        Region 5: I/O ports at 9c00 [size=64]

In particular, what does the "size=foo" mean?  The most likely seems
to me to be the number of octets available starting at the indicated
port address.  But other interpretations are possible.  Can anyone
tell me with some confidence how to interpret the size number?


-- 
Russell Senior, Secretary
russell at personaltelco.net