Booting Fedora on an old 7248

[Ingvar Hagelund]

* Josh Boyer
>>> The B50 is a CHRP machine.  The 7248 is a PReP machine.  Fedora does
>>> not support PReP machines.  

I know, as I said in the posting, "It didn't work, of course", but since
it was possible to make PReP boxes boot off a CD in the old days, I
thought that perhaps it was doable or at least fixable.

I heard on IRC a few days ago that support for the PReP platform is
still compiled into the Fedora ppc32 kernel, and that there was still a
few people using Fedora on PReP, even though they had to figure out the
installation on their own.

I guess I should start out by dd'ing the ppc32 kernel to my PReP boot
partiton and see what happens.

* David Woodhouse
>> It shouldn't actually be that hard. Just feed it a flattened device-tree
>> from your bootloader and it should be fine.

How? What flattened device-tree? What bootloader? There is no
OpenFirmware access to the device tree. Just a old-style BIOS-like firmware.

* John W. Linville
> What PReP bootloaders exist?  When I was using my 7248 in the
> past, I always just booted a floppy that had a kernel dd'ed to it.
>
> Alternatively you could boot from a PReP partition (type 41) with a
> kernel dd'ed to it.

Yes, but when you compiled those kernels, you marked the machine type as
prep, and then a small prep bootloader was compiled and piggybacked on
top of the prep kernel image. When you bootet from a floppy or a PReP
partition, that small bootloader was loaded first, and it in turn, gave
options to, started the actual kernel. It may be possible to boot the
kernel directly, but as you can't give options to it, it becomes more
difficult to make things work.

> Anyway, if you know of a bootloader for PReP I'd like to hear about it.

I think the old prep bootloader was found in the kernel tree, in
somewhere in arch/ppc/boot/prep/misc.c and friends. It seems that it
still exist in 2.6.26.5.

> I imagine that you might could implement a kexec-based loader nowadays
> as an alternative.  Well, I'm rambling...

I thought about it a few years ago, using a small kernel with that old
prep bootloader, and then some some scripting and kexec to jumpstart the
"real" kernel, but I never got around to get it off the droodle board.

Ingvar