[coreboot] coreboot + Linux = ?

[Peter Stuge]

On Sat, Mar 15, 2008 at 06:22:41PM -0800, ron minnich wrote:
> On Sat, Mar 15, 2008 at 6:11 PM,  <joe at smittys.pointclark.net> wrote:
> > > coreboot is an alternative. I was asking if anyone knew about
> > > interest for a stronger bond between coreboot and Linux.
> > 
> > Ah, gotcha...
> 
> Actually, it requires only that somebody start dropping patches in.
> But what, really, do we need?

As you know my grand plan is to get rid of all things legacy. I do
think there is, or will be, a need.

On the way to that 2.6.24 I took a detour into Ulrich Drepper's
excellent What Every Programmer Should Know About Memory.

On the topic of HT hypercube information in sysfs:

--8<-- http://people.redhat.com/drepper/cpumemory.pdf page 45
Each processor constitutes its own node as can be seen
by the bits set in the value in cpumap file in the node*
directories. The distance files in those directories con-
tains a set of values, one for each node, which represent
a cost of memory accesses at the respective nodes. In
this example all local memory accesses have the cost 10,
all remote access to any other node has the cost 20. [26]
..
[26] This is, by the way, incorrect. The ACPI information is appar-
ently wrong since, although the processors used have three coherent
HyperTransport links, at least one processor must be connected to a
Southbridge. At least one pair of nodes must therefore have a larger
distance.
-->8--

For people to do a really good job with libNUMA it seems benefitial
to replace the wrong information with something that is right.

Any advantage coreboot can offer is good I think.


//Peter