[coreboot] CarPC project, with MB899 MB

Peter Stuge peter at stuge.se
Thu Oct 14 00:58:41 CEST 2010

Nasa wrote:
> > Did you pick a particular CPU for the board, or did the CPU come
> > already installed when you bought the board?
> I choose the CPU (a number of years ago) which is an Intel Core 2
> Duo Mobile 1.66GHz.

Ok. I don't know if this CPU has been tested with coreboot, but even
so it is possible that it will just work<tm>. You should give it a

> I have read a little about payloads and noted that SeaBIOS would be
> the easiest way to go... However (this being important for the
> flash chip), I didn't see anything about the benefits of putting a
> linux kernel as a payload.

Benefits are that fewer steps are required to boot the system, so
with the kernel in boot flash you can immediately access the root
filesystem regardless of where it is stored.

> I did read from the FAQ that most chips aren't large enough to have
> the kernel added as a payload.

The FAQ needs some updates. I guess "most" chips still aren't large
enough for a kernel, but those 16Mbit chips should be able to hold a
monolithic kernel optimized for a single board.

> If my goal is the fastest boot time possible, while still
> supporting the basic system, would going to a Linux payload be the
> way to go?

Maybe, but maybe not. If you are using flash media which does not
have a spin-up delay then it might actually be faster for another
payload to load the kernel off the drive using DMA.

> If so, what size flash chip should I get?

The larger the better IMO. There can be a chipset limit for the flash
chip size, but I don't know what it is for i945 chipsets. In any
case a larger flash chip will still be usable, just at e.g. half

> BTW: once I get this working, it's going up on the carpc forum -- I
> know a lot of people would be interested in reducing their systems
> boot time.

Yes. It's also the first thing I used coreboot for myself. Please
mention that it is very important for people to check if their
mainboard and/or CPU+chipset is already supported, otherwise they are
looking at rather large projects of studying PC architecture and
developing lots of low-level code to implement that support. An
unsupported mainboard with a supported CPU+chipset is much less
effort though, and could best case be just a few days-few weeks
project for a C programmer.

For new installs of course hardware known to be coreboot confirmed
would be best. :)


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