[coreboot] Rebuilding coreboot image generation

Julius Werner jwerner at chromium.org
Sat Nov 21 01:08:17 CET 2015

> Let's extend your example so it becomes somewhat comparable to my proposal:
> [...]
> And that for every mainboard, and not transferable to other flash
> layout schemes.
> I don't think this is looking better (or even just as good) as my
> proposal, simple because of maintenance reasons.

Sorry, I'm not quite sure how to read that... did you literally mean
that the cbfstool commands (or something equivalent) would be *in* the
.fmd file? That is certainly not what I meant.

Instead, I was suggesting to use well-known CBFS "categories" and have
another part of the system (e.g. the Makefiles) map files to those.
For example when something (a mainboard, an SoC, etc.) declares a
file, it would declare that this file belongs to the "pre-boot-split
CBFS" category or the "post-boot-split CBFS" category (or for all I
care you could also bind them directly to romstage/ramstage/etc. which
is I think closer to what you were proposing). Then the part deciding
the boot scheme ("vboot" and "traditional coreboot" for now) would
know that all "pre-boot-split" files would belong into the well-known
CBFS FMAP sections "FALLBACK" and "NORMAL" for traditional coreboot,
whereas "post-boot-split" would only go into "NORMAL" (and the vboot
version would instead know how to bind those categories to its
RO/RW_A/RW_B sections). The .fmd file should *only* define the layout,
and all the individual platform pieces that need to add files should
*only* declare something abstract about in which context those files
are used. Then something else (which is deciding the general boot
method) should define how to bind those two together.

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