Subject: Re: BT946C support -- maybe I _am_ an idiot?
To: None <>
From: Charles M. Hannum <>
List: current-users
Date: 08/29/1994 21:54:48
   Many motherboards seem to ship with all the PCI interrupts switched

`Oh joy.'

   To make it work correctly, the "PIN" setting in the "Auto-SCSI"
   adapter BIOS has to be set to the letter of the PCI INterrupt (ever
   wonder what PIN stood for?  Nice that the BT946 manual documents
   it, huh?)

Actually, in the PCI spec it corresponds to one of four real pins.
However, the spec specifically says that a single-function board
should only use INTA#.  I can only guess that the slot itself is
supposed to wire the interrupt lines to whatever IRQs on the
ISA-compatible interrupt controllers.

(If anyone knows more about this, speak up!)

Currently, the PCI autoconfiguration code relies on the PCI BIOS to
have stored the number of the ISA interrupt line onto the board.  This
is really all I can do without getting into horrible chipset
dependencies that I really don't want to think about.

   Could the kernel autodetect some of this stuff?

There is currently no specific PCI support for the BusLogic
controllers; they are just used as if they were EISA or VLB boards.
If you'd like to add some PCI autoconfiguration support for them, I'd
probably recommend that you wait until I switch the i386 port to using (shortly after the 1.0 release), since it's likely that
code would end up being significantly different.

   Where do I get a copy of the PCI spec?  The number I have for
   Intel's PCI group seems to be no longer in service...

1-800-433-5177 is the current number, as far as I know.