Subject: Booting CD-ROM via Snag "C"
To: port-macppc <port-macppc@NetBSD.ORG>
From: Bob Nestor <bob@murphy.dyndns.org>
List: port-macppc
Date: 09/05/2004 08:44:59
The instructions for building a Snag "C" bootable CD-ROM are incomplete 
for many newer Macs.  These changes have allowed me to produce a CD-ROM 
that is Snag "C" bootable on B&W G3, eMac and 12" PowerBook.

Basically Openfirmware in newer model Macs doesn't appear to enable 
screen output by default as older versions did.  The solution is to add 
the following command to the bootscript file right before the boot 
command:

	" screen" output

The quotes and leading space on "screen" appear to be required.

Also the netbsd kernel file must be visible to Openfirmware.  If you 
copy the file to the root level directory of your CD and use the 
-hide-hfs-list option in mkisofs with the supplied hide-hfs-list, the 
kernel file will be hidden and ofwboot will be unable to find it.  My 
solution was to not copy the kernel file to the root level directory of 
the CD and modify the boot command in the bootscript to:

	boot cd:,\ofwboot.xcf \macppc\binary\kernel\netbsd-INSTALL.gz

Notice there is no device specifier in the kernel filename argument.  
Although ofwboot indicates it will accept one it doesn't appear to 
work.  It seems the default boot device becomes the device that ofwboot 
was started from so leaving out the device specifier wrk just fine.

And finally, ofwboot in -current is version 1.10 and it doesn't work on 
any of my systems. I've used version 1.7 which came with NetBSD-1.6.  
It works fine on all the Mac systems I tested and it successfully loads 
-current kernels.

If you try this out on your system and it doesn't work, please let me 
know.  Otherwise I'll get the instructions updated in the NetBSD 
documentation.

Thanks,
-bob