[coreboot] [PATCH]Move option table to CBFS

Stefan Reinauer stepan at coreboot.org
Fri Jan 14 20:18:56 CET 2011

* Patrick Georgi <Patrick.Georgi at secunet.com> [110114 11:39]:
> Hi,
> currently the option table (which contains the metadata necessary to
> parse CMOS data properly) is stored in ramstage. This patch moves it to
> CBFS, making it available for inspection by utilities.
> The idea is to allow nvramtool to configure cmos defaults (which are
> stored in CBFS) by using the table (also stored in CBFS). This requires
> some changes to nvramtool, but this is the only necessary change in
> coreboot to allow this.
> The downside is that cmos_layout.bin is not compressed, while ramstage
> (and thus the layout information it contained) usually is. With layout
> data being 2kb or less that shouldn't be much of an issue.
> Right now, the table is copied into cbtable by coreboot, like it used
> to. It would be possible to just link it to the end of cbtable, making
> the chain run into flash space, but I didn't do that to minimize the
> impact of this patch. I'm not sure if reducing cbtable's RAM use by 2kb
> is worth the potential trouble.

> Signed-off-by: Patrick Georgi <patrick.georgi at secunet.com>

> +		struct cmos_option_table option_table = cbfs_find_file("cmos_layout.bin", 0x1aa);

Make sure to also teach the magic value to cbfstool (and possibly add a
magic value to some coreboot include file and use that instead) Those
file types are increasingly hard to keep track of.

Acked-by: Stefan Reinauer <stepan at coreboot.org>


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