On Wed, Oct 21, 2020 at 4:00 PM Nico Huber nico.h@gmx.de wrote:
On 21.10.20 21:19, Tim Wawrzynczak via coreboot wrote:
Currently there are 3 different "strapping" entries in the coreboot
tables,
and with the recent addition of fw_config ( https://review.coreboot.org/c/coreboot/+/41209), we would also like to
add
the 64-bit fw_config field (updated here https://review.coreboot.org/c/coreboot/+/45939) to the coreboot table as well.
In this patch (https://review.coreboot.org/c/coreboot/+/46605), I am proposing to deprecate the 3 current "strapping" entries (board ID, ram code and SKU ID), and add them all to 1 entry, containing board ID, ram code, SKU ID as well as fw_config. This saves the overhead of parsing 4 different entries to obtain board configuration information.
Would like to hear any thoughts on this,
I'm actually very confused about these things and how they are supposed to be used. Is it correct to say that there are / would be coreboot table entries with board-specific encodings?
There already are :) Board ID, SKU ID, and RAM Code are inherently mainboard (family) or vendor specific conventions. I see FW_CONFIG as yet another one of these strapping fields.
Wouldn't it be better to decode the infos first and put that into tables so generic drivers can consume them?
That's an interesting thought, Nico. Can I assume you're talking about the coreboot table here?
What I'm trying to accomplish here is to be able to pass the FW_CONFIG value from coreboot to the payload, in my case, obviously depthcharge. You can see some of our uses for fw_config in coreboot already, in mb/google/volteer for example. Some of the fields are distinguishing which daughterboard or audio device is on a given mainboard, which in these cases is not enumerable information, hence my thought to pass the fw_config value to the payload. This alleviates needing the payload to know where this information came from, as coreboot has already done the work to figure that out.
Generally, I wouldn't assume / want board-specific drivers outside of coreboot. It seems board-specific table entries would invite people to write such
I don't think this is encouraging board-specific drivers; just trying to pass information to the payload here, that's all.
Sorry if I completely misunderstood the intention of these entries.
I just hope I have explained myself well enough for others to understand :)
Nico _______________________________________________ coreboot mailing list -- coreboot@coreboot.org To unsubscribe send an email to coreboot-leave@coreboot.org