[Thinstation-developer] PowerPC port (Mac Mini as thin client)

[Paul W. <pa...@si...>]

FYI, I am currently in the early stages of porting DIET-PC to PowerPC 
(using a G4 Powerbook).  I have successfully booted an image that 
launches X.Org and fullscreen rdesktop via DHCP and TFTP.  I don't 
actually own a Mac Mini, but I expect that the changes required to get 
this working would be trivial (mostly just kernel driver differences).

If the Thinstation project has any interest in doing a PPC port, I can 
offer some advice on how to get Linux network booting working (this is a 
relatively undocumented area, and there are some pitfalls), and possibly 
do some testing for you if time permits.  You could use SourceForge's 
Compile Farm to do the bulk of the porting work "blind", and then get 
someone with a Mac to test the results.

Some things to look out for:

- Apple uses a modified DHCP protocol that necessitates a patched DHCP 
server (there is a patch available for ISC DHCP 3).

- There is only one viable boot loader, and that's yaboot.  It's 
LILO/GRUB/Syslinux-ish and pretty capable, but the front ent (ybin) 
doesn't cater to network boot at all, so I've had to figure that out for 
myself.  You need a first-stage FORTH script bootstrap (ofboot.b) 
followed by a second-stage yaboot binary.

- In the Apple universe, there's no such thing as VESA.  All of your 
graphics are achieved via framebuffer drivers (eg. X.Org fbdev driver), 
including the text console.

- There are some user interface issues to deal with, such as different 
keyboard layouts, how to cope with a single-button mouse, and a 
different key combination for VT switches.