If you've successfully gotten 32-bit PowerPC Debian installed using one
of the recent Debian Ports snapshot CDs (I used
https://ftp.acc.umu.se/cdimage/ports/snapshots/2020-11-09/debian-10.0.0-powerpc-NETINST-1.iso)
but have no installed bootloader (grub install fails), here's what you
can do to temporarily boot in to this installed environment:
1) After the install completes, re-boot _with the installation CD still
in the drive_
2) Break in to GRUB, and type 'c' to get to a grub command line
3) Run the following commands from the GRUB CLI, substituting
apple3/sda3 for the appropriate volume where /boot was installed to.
insmod part_apple
insmod ext2
'linux (ieee1275/hd,apple3)/boot/vmlinux root=/dev/sda3'
initrd (ieee1275/hd,apple3)/boot/initrd.img
boot
...and your machine will boot to the installed environment.
I then installed the 'git' Debian package, and cloned the yaboot4 git repo:
git clone --recurse-submodules https://github.com/rsaxvc/yaboot4
...and then compiled it with 'make'
...and then did a 'sudo make install'
...and then manually edited /etc/yaboot.conf with correct arguments:
image=/boot/vmlinux
label=Linux
root=/dev/sda3
initrd=/boot/initrd.img
read-only
...then ran 'ybin' and rebooted. And it results in a working environment.
