mptables and missing devices

[Eric W. Biederman]

ron minnich <rminnich at lanl.gov> writes:

> On 30 Sep 2003, Eric W. Biederman wrote:
> 
> > There are boards that a pirq routing table simply does not work
> > for, because not all interrupts go through the pirq router.  For those
> > boards we either we need to just go through the mptable, or we
> > need to pre route the irqs and fill in the routing in pci space.
> > Pre routing the irqs is the most compatible with multiple kernels and
> > OS's.
> 
> still worse, there are those cases (Linux) where the interpretation of 
> PIRQ is broken (e.g. for Geode). So I've reluctantly come to the 
> conclusion that LinuxBIOS should do this routing.
> 
> > Once we get that we can figure out how to export that information
> > via the LinuxBIOS table, the mptable, and pirq table.  I am tempted at
> > that point to move the mptable and pirq table  generation code into
> > mkelfImage, and to start looking at having the kernel support the
> > LinuxBIOS table directly.
> 
> we need to leave them in LinuxBIOS, I think, so that I can continue to 
> support 9load, plan 9, and all the other systems that want to read PIRQ. I 
> would hate to see mkelfImage get too complicated, as I need to be able to 
> generate these elf Images on systems that have no GNUbin utilities.

mkelfImage 2.x does not have a binutils requirement, except when it is built.
mkelfImage 2.x is a standalone C binary.

Removing the non native interface from the core is something I'm playing with.
It is not something I care about much either was as long as we have a
good native interface.  But it should not much matter if we actually
pre route the irqs.  As suggested for the Geode.

In addition if we have maintain a subset of the kernel that
understands native LinuxBIOS tables then we define the proper
interpretation of the tables and we can say who has the correct
interpretation.

But I totally agree this is something we need to move forward slowly with.

Eric