[coreboot] [cbv2]Add serial port information to lbtable

Torsten Duwe duwe at lst.de
Tue Jan 22 11:45:08 CET 2008

On Monday 21 January 2008, Patrick Georgi wrote:

> This record is intended to tell the payload about the existence and
> where-abouts of a serial port. A console would be a separate record with
> that number you propose (or something like that)
> If and where a serial port is to be found is an information that should
> be provided even if (say) vga is being used for the console, in my
> opinion.

Can you elaborate that? I cannot think of a good use a payload can make of a 
serial port other than console (please not PPP booting over modem ;-). And 
operating systems will find them their own way.

> As for the layout of the LB_TAG_CONSOLE (which has to come, eventually),
> there was some discussion on IRC already, but I think it quickly became
> over-engineered.

It's good to have multiple places to discuss things :-/ Is there a log?

> The tag number is already taken in v3, so 0xe must be changed (just for
> reference).
> I'll post another patch, with a new ID (a v3 patch exists and works
> already, that'll come, too) and work on a proposal for LB_TAG_CONSOLE -
> tomorrow.

First we should all agree on what the structure is. I'd like to read the IRC 
log to pick up those arguments. My current opinion is that LB_TAG_CONSOLE 
should do it all. Maybe also LB_TAG_ALTERNATE_CONSOLE in case the payload 
lacks certain drivers, and can not use coreboot's preference. This would 
carry all console information, you would be able to describe all serial ports 
if you like, it's not overly complicated and can be achieved with minimal 
changes to your current patch.


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