I've updated the mirror a bit with new packages and fixes, and almost always remembered to put something in the Changelog.txt, almost.
There is now an .iso file on the mirror.
https://mirror.riscyslack.org/RiscySlack/current-iso/I tested it by mounting it as a virtual drive in the OpenBMC console.
Petitboot detected it and allows it to boot.
After that you can fdisk or cfdisk your drives and run Setup like a normal Slackware setup.
You'll have to ignore the MBR error and tell it not to install Lilo.
I haven't modified the Setup script to remove that yet.
After installing you'll need to exit back to bash and chroot /mnt
then run grub-mkconfig -o /boot/grub/grub.cfg
After rebooting Petitboot should detect the install and automatically load it.
If you use the NIC that's shared with the BMC you'll want to edit /etc/rc.d/rc.inet1.conf to set eth2 USE_DHCP[2]="yes"
I've also noticed the gpu doesn't always reinitialize on my Radeon RX580 after reboot.
When that happens I end up having to shutdown, then boot back up.