Interfacing FreeBSD with U-Boot

[Rafal Jaworowski]

M. Warner Losh wrote:
> In message: <478CD60B.7040901 at semihalf.com>
>             Rafal Jaworowski <raj at semihalf.com> writes:
> : Hi,
> : 
> : The topic of integrating FreeBSD with U-Boot has already been discussed here,
> : so I'd like to let people know that the following code has recently been
> : integrated with main line U-Boot:
> : 
> : http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=commit;h=500856eb1707ed17d9204baa61dd59948d3b2899
> : 
> : This brings a machine and arch independent API which allows to utilise U-Boot
> : facilities (console, storage, networking) in standalone applications; the
> : interface was developed in order to have embedded FreeBSD/powerpc running on
> : U-Boot-based devices in native and uniform manner: loader(8) runs as a
> : standalone application on top of U-Boot and kicks off the kernel as expected.
> : 
> : Initial code for loader(8) + gluing with this new API is available on the P4
> : e500 branch, and was tested with Freescale MPC85xx PowerPC systems. It mostly
> : comprises a generic lib, with only a tiny and well defined piece dependent on
> : the machine so that other embedded architectures (ARM, MIPS) can use it with
> : minimal effort.
> 
> This is great news.  I'll see about getting the necessary bits for the
> arm and mips stuff I'm working on in shape.
> 
> I'm curious about one thing.  What would happen if one were to boot
> the kernel directly on an unmodified uboot system?
> 

Pretty much what we had to the moment: in such case the kernel needs to be
loaded to memory manually at U-Boot prompt and control passed to it
explicitly. It would learn it hasn't been provided with regular metadata from
the loader and fall back to some built-in settings...

BTW: I have some preliminary ARM loader(8) gluing already written, but didn't
manage to test the new API with this arch yet, but this will happen eventually :-)

Rafal