Re: Netbooting a blue and white G3

[Nathan Whitehorn <whitehorn%wisc.edu@localhost>]

Flavio Donadio wrote:
> Nathan,
>
>
> Well... Since I am a "mere mortal" NetBSD user, I was pretty sure 
> somebody already had the same idea or maybe a better one! :-)
>
> I was thinking about the technique and I have to ask: you don't really 
> have to format the partition as HFS before doing a block write of an 
> image file to it, huh? If so, you don't even have to "prepare" the 
> partition before starting from the CD.
I'm not completely sure I understand the question, but I'll try. This 
generates a raw HFS image (boot1.hfs) that you can dd to an 800K 
partition you make with pdisk, so there is no preparation necessary with 
other operating systems or hfsutils or anything else. In principle, the 
installer can just block copy it to a partition like it would a boot 
block. The idea is that it can work like the boot block does on x86 or 
sparc, installing some stub loader you never really need to update that 
loads the real loader from UFS -- the boot block internally just 
happening to be a small HFS filesystem.

It also gets around a build dependency on hfsutils by making a 
"template" HFS disk image with some magic strings where the relevant 
files need to go using hfsutils. This is then saved and put in CVS 
(hfs.tmpl.bz2.uu), and the block offsets of those two files (found with 
grep) and saved in Makefile.hfs. The regular build system then builds 
the loader, expands the template image, and dds the loading binary into 
the file system at the appropriate offset. It's a dirty, horrible hack, 
but it seems to work well. You can see the details in the Makefile and 
generate-hfs.sh.
-Nathan