BIOS and Clocks

["Terje Melsom, VMETRO" <terje@vmetro.no>]

Hi,
I have two questions related observation we have made when debugging a
driver problem on a dual Pentium-II motherboard.

1) When the PC boots, the clock signals to un-populated PCI slots are
disabled after a few seconds. Does anyone know how this is done? It does
not seem to be controlled using the PRSNT pins, but rather by which
boards respond in config space. Is this a feature of the motherboard
that can be turned of for the purpose of debugging? How common is this?

2) We have a board with a Windows-NT driver that does not work on this
specific motherboard. What we see is that the BIOS assigns base
addresses in both memory and I/O space to the PCI interface, but leaves
it in a state with memory and I/O space disabled. In most other systems
we have observed that the BIOS enables memory and I/O space. Are there
rules or a recommendations on how the BIOS should behave in this matter
?

Thanks for your help
--
Terje Melsom