Subject: Re: Native BSD booter
To: None <port-mac68k@netbsd.org>
From: None <CaptnZilog@aol.com>
List: port-mac68k
Date: 01/31/1999 14:50:58
just a note about this topic...

I took a course several years back (hmm.. probably 5+ actually) on Mac
software/system debugging (I do PC/Mac/Unix support at work, although Mac's
are getting phased out now... no new purchases allowed... and I have a *pile*
of old ones at home now that they were tossing... several IIcx's & ci's, two
si's, an LCIII, and three SE/30's)...  anyways...

The mac's rom's find the first Mac HFS bootable filesystem on the disk and if
there is no pointer in the boot sector to the "blessed folder" (the "blessed"
folder #) it searches the HFS drive for a file called "system" to boot.  I
would think that, in theory, if you had enough knowledge of how the "system"
file was made, you could replace the whole system file with a booter
program...  you would still need a Mac HFS partition though, even if it was
only a 1Mb or less for the booter.  Since you wouldn't have the Mac OS
available at that point, the loader obviously couldn't use anything other than
possibly some of the ROM toolbox routines... and maybe not even those since
I'm not sure what other hooks the OS may put in to make them run.   At the
least, I'd bet you could still use the low-level disk I/O routines though.

Trivia for you cx/ci owners:  The official Apple terminology for the plastic
bracket on the cx/ci series that the floppy & hard drive's mount onto is "the
wierd thing".

Pete Hufnagel
CaptnZilog@aol.com