[LinuxBIOS] New LAR access functions

Stefan Reinauer stepan at coresystems.de
Thu Jul 12 19:00:44 CEST 2007

* Jordan Crouse <jordan.crouse at amd.com> [070712 17:27]:
> > > A normal LinuxBIOS upgrade shouldn't touch the bootblock;
> > 
> > I agree. That's why lar should know about flash chip sector sizes.
> This is probably best - lar is best suited for doing the math and
> making sure that the blobs are written out in the right format. Somewhat
> safer then making flashrom rearrange the bits later.

Actually both lar and flashrom should be able to read flash chip
description files. 

> I'm thinking that we could probably get away with someting simple like
> a -S <sector size> option, and LAR would would arrange the archive
> correctly, and then write the sector size along with the total ROM size
> in the "bootblock header".

Sectors might have different sizes. Not sure whether this "assymetrical"
concept will be kept up in the future. Many modern chips are
"symmetrical", ie have all equal sized blocks.

> flashrom should at the very least know how to read a lar and make sure
> it is sane.  If we include the sector size from above, then flashrom 
> could do some very basic sanity checking before starting.

It would be nice if flashrom knows how to flash a part of a lar. ie
"only normal, not fallback" But 90% of flashrom's flash chip drivers
dont know how to do that, and it would be quite some redesign to change
> > But it creates another quite real problem for the first upgrade to LB
> > where we need to distribute the bootblock separately. I think that's
> > a _really_ undesirable scenario. :\ Especially since it will be the
> > common case for some time still.
> > 
> > One file is no file, two files are two files too many. ;)
> I completely agree.  Its always best to only have a single deliverable.

It should be viable to flash "everything but the bootblock" in lar. But
for deployment a complete image is what we really want. The fact that
the bootblock is part of the lar is just artificial to make the handling

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