[coreboot] Need new type for CBFS

Kevin O'Connor kevin at koconnor.net
Mon Aug 10 01:41:24 CEST 2009

On Sun, Aug 09, 2009 at 11:16:49AM -0700, ron minnich wrote:
> Definitely don't use NULL for anything -- it's a free space marker as
> patrick points out.
> The type is actually
>         unsigned int type;
> I would make the following proposal: we reserve the range 0-255 for
> cbfs "system" (i.e. coreboot) use and open up the rest of the range
> for any other use. Then we allow people to register types on the wiki
> in some way.
> I can't believe coreboot will ever need more than 256 types, and I
> can't believe the community will ever need more than 16M.

I believe the community doesn't need any types.  I fear we're creating
work that doesn't need to be done.  (Why maintain a wiki and/or build
a standard around a feature that isn't needed?)

Of the four types defined:

null - can be implemented by setting the first character of the
    filename to 0 on deleted files.  This is actually easier for file
    finding code because then it can just do a filename search and not
    have to worry about matching deleted files.

stage - instead of having a type in the cbfs header, a signature can
    be added to cbfs_stage.  The same validity check can then be done

payload - same as 'stage' - add signature to cbfs_payload.

optionrom - isn't actually in use.  Both SeaBIOS and coreboot expect
    to find option roms without any special header.


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