[coreboot] Need new type for CBFS

Patrick Georgi patrick at georgi-clan.de
Sun Aug 9 19:36:32 CEST 2009

On Sun, 09 Aug 2009 18:55:38 +0200, Thomas Jourdan <tjourdan at neuf.fr>
> I was playing with CBFS and I found an strange behavior. There are
> actually 4 types of files in a CBFS rom : stage, payload, option rom and
> NULL. The latest is used when we don't care of the component type. 
No, the latest is used for free memory regions.
You can define 256 different types, of which 4 are predefined, and there is
some rough partitioning of the file type space - that you can honor, or

> I guess if we want to embed a logo, payload specific data or other
> stuffs, we must use this NULL type. The problem is that the free space
As said, NULL is not suitable for that. So your conclusions are wrong.

> What do you think ?
Define whatever types you want, expect problems as the numbers might be
reused at some point. CBFS isn't finished yet, and it isn't even clean
enough at this point to define stable contracts about it (eg. file types
beyond what we already have)

> Bonus question : shouldn't the cbfs code (to parse, find a file...) be
> added to the libpayload ?
Yes, at some point. Properly licensed, and properly designed, once CBFS
itself is stable enough. There are only 24 hours in a day (that also
applies to CBFS development).

CBFS is already an improvement over the old layout in its current state.
You're moving beyond what CBFS can provide right now if you put any data
into it that isn't supported by the coreboot build system. Future proof
designs and implementations welcome.


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