Re: hfs boot floppy versions
On Mon, Oct 31, 2005 at 02:56:52PM +0100, Christian M?ller wrote:
> * http://www.netbsd.org/Ports/macppc/SystemDisk-tutorial/ (NetBSD also
> messes with real-base, sure they will have their reasons, but it will
> make a dual boot machine to a classic mac os uncomfortable - though mac
> os boots with the tampered with real-base, but resets it to default.
> i've read about systems prior to the beige G3 that reset many more of
> the boot variables to defaults <- maybe hack a forth script into nvram
> named bootlinux/bootbsd that sets proper variables and afterwards does 0
> bootr if there is space in nvram for own forth functions <- are they
> kept like varaibles I set??)
I'm pretty sure my 7600 reset everything on a mac boot sequence. I know
it cleared out the patch for the control video mode bug.
> Somewhere I read a post saying that it might be possible to load a
> vmlinuz.xcoff directly via OpenFirmware command (which would render the
> extra ofwboot.xcf NetBSD uses pointless), I did not succeed in doing
> so. I tried it with boot-devie set to
> ide1/@0:,\INSTALL\POWERPC\VMLIN001.INI - if someone succeeded with
> something like this, please come forward =).
One of the early linuxppc installers did something like this. A kernel
and initrd were packaged up into a file called vmlinux.coff, which was
then written to an HFS floppy. The firmware was told to boot from the
path "fd:vmlinux.coff", and it read and executed the kernel directly
from the floppy. It looks like some of that support is still in the
kernel tree even in 2.6. Take a look at arch/ppc/boot/utils/hack-coff.c
and arch/ppc/boot/openfirmware/coffmain.c for more info. I seem to
recall that it wasn't very reliable. The driver for the floppy controller
in OF didn't have very good error handling, so if it had any trouble
reading the floppy, it failed.
Brad Boyer
flar@allandria.com
Reply to: