Thanks Micha,

The exemplar fmd you linked is very close to the simplest scheme I imagine.

I may be going to work on the build system, in order to generate such fmd automatically in the future, since there is a Kconfig variable CBFS_SIZE which actually stands for the size of SI_BIOS section, and sizes of SI_DESC, SI_GBE and SI_ME section can be inspected from the IFD file via ifdtool.

On Thursday, August 8, 2019 8:12 AM, Michal Zygowski <michal.zygowski@3mdeb.com> wrote:

Yes, if you are interested entirely in measured boot mode only, the RO section is sufficient.

The GBB is much greater since ChromeOS recovery bitmaps resides there. For non-ChromeOS devices (like many Lenovo laptops implement in coreboot) I saw min 120KiB (0x1e000). Should be sufficient. Example fmap description of flash with RO section:

https://github.com/coreboot/coreboot/blob/master/src/mainboard/ocp/wedge100s/vboot-ro.fmd

(probably you would like to adjust some offsets and sizes)

Best regards,

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Michał Żygowski
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