you da man, farruiin!
for all those who r nOO to this (like me), once you've booted into the Debian boot installer, you need to first execute a shell (from the menu)
Next, mount your hfs partition using:
mount -t hfs /dev/hdaX /target (given that you've installed it on an ide drive - sda for SCSI)
After that, create a directory for the linux files:
mkdir /target/nix
then mount your linux partition:
mount /dev/hdaY /mnt
next copy over the contents of /boot:
cp /mnt/boot/*.* /target/nix
And finally, boot into OS9, place the kernel(s) in the kernels folder (the one containing vmilnux) and the images outside of that in the System Folder.
The first time you start from BootX, designate the RAMdisc as the one labelled configure, so the install can finish. Then next time you boot, do so from your linux partition, hdaY