[LinuxBIOS] PCI: Left over static devices. Check your Config.lb

Steve Isaacs yasteve at gmail.com
Mon Dec 10 21:29:03 CET 2007

On Mon, 2007-12-10 at 09:05 -0800, ron minnich wrote:
> On Dec 10, 2007 7:51 AM, Steve Isaacs <yasteve at gmail.com> wrote:
> > That's something I don't understand. What is essential and what is not?
> Essential is "needed to configure machine to load Linux". Which really
> means that devices for it exist in the device tree, and those devices
> need to run some code to make the node boot.
Can I assume that the list of devices needed to load Linux are a subset
of devices needed to run Linux? 

Just so I know I understand, let's say what I need to boot Linux is RAM
and an IDE interface (on the southbridge). What I need to run Linux
includes the IDE interface plus SATA, USB, (all on the southbridge)...
Does Config.lb need to list these interfaces in order to run Linux or is
it expected that the Linux kernel will take care of that part?

> > e.g. Can I leave out the 18.x as well and LB will auto-detect like it
> > did for node 1 (19.x)?
> Those are northbridge register on k8 and on a 2-cpu system you need
> them. But do you need them in Config.lb? You know, I just realized, I
> don't know :-)
Using some info in the doc Uwe reminded me of could I say that
northbridge 18.* is necessary because the southbridge is connected to
it? Whereas, for my board, I don't need to list northbridge 19.* because
none of the "essential" devices are connected through it? (disregarding
RAM of course)

> Even disabled, they are still in the static tree. I am saying to not
> even list pci devices (particularly slots) if they are not needed to
> configure the platform for linuxbios. In many, many cases, all you
> need are the IO APIC, the superio, the CPU, and that's it. We have
> poor documentation and as a result people tend to put more in
> config.lb thany they need.
This makes me wonder about the semantics of the phrase "Left over static
devices." Is this saying there are devices listed in the Config.lb that
do not exist on the board or that there are devices on the board that
are not mentioned in Config.lb?

Thanks to all for bearing with me on this. I need to understand this
since real hardware arrives next week and is a different design.


More information about the coreboot mailing list