Porting FreeBSD to PowerPC 860 ?

[Morton Lin]

>  The 860 is quite different than the G3/G4 processors currently supported
> by the port
>
>  - no BAT registers
>  - the MMU is a simple TLB, unlike the OEA h/w tablewalk in the G3/G4
>  - no floating point
>  - a huge amount of system-on-chip logic and peripherals

Hi, Peter :

Sorry for my response is so late. You are absolutely right.

After few days survey, I found maybe I should start from Linux
(MontaVista, penguinppc, eCos, ...) for PowerPC to learn more
things. Another issues probably are :

1. Big/Little Endian
2. Boot loader
3. Kernel / driver porting
4. ....

It seems Embedded Linux had a more mature developed environment.
So I will stay there to learn something about basic knowledge and tech.
Then I will come back for FreeBSD.  :-)

>  It will be quite a lot of work to get FreeBSD running on an 860, but I
have one,
> and it is my long term goal. I greatly encourage you to join in the fun
:-)
>
>  The NetBSD port to the IBM 4xx is a good place to start: the 4xx is
similar to the
> 860 in that there is only a TLB for addr translation, and it has no
floating point.
> A lot of device driver work needs to be done to support the inbuilt
peripherals.
>
>  Also, the current port is closely tied to OpenFirmware - that has to be
split out,
> and you have to find a way to get the loader to run. I'm not sure what ROM
monitor
> the EmbeddedPlanet boards have, but if it's U-Boot, then there is a bit of
work
> to be done to interface FreeBSD's loader to it.

Valuable information ! Thanks a lot.
I will dig into those source tree after I have enough knowledge about
"RIGHT THING" and give it a try.


Best Regards,
Morton Lin.