The CATS emulation mode is working well enough to run old versions of NetBSD/cats and OpenBSD/cats.
Debian GNU/Linux could perhaps run in the future.
Known issue: Clocks inside the emulated guest OS run at the wrong pace.
It is possible to install and run NetBSD/cats in GXemul.
To install NetBSD/cats onto a disk image, follow these instructions:
dd if=/dev/zero of=nbsd_cats.img bs=1024 count=1 seek=6000000
ftp://ftp.de.netbsd.org/pub/NetBSD/iso/8.0/NetBSD-8.0-cats.iso ftp://ftp.de.netbsd.org/pub/NetBSD/NetBSD-8.0/cats/binary/kernel/netbsd-GENERIC.aout.gz ftp://ftp.de.netbsd.org/pub/NetBSD/NetBSD-8.0/cats/binary/kernel/netbsd-INSTALL.aout.gz
gxemul -X -E cats -d nbsd_cats.img -d NetBSD-8.0-cats.iso netbsd-INSTALL.aout.gzand proceed like you would do if you were installing NetBSD on a real CATS from CDROM.
Note that there may be some long delays during bootup.
Alternatively, to install from FTP, you can skip downloading the ISO, and start the install without -d xxxxx.iso. Suitable network settings are IP 10.0.0.1, gateway/default route 10.0.0.254, netmask 255.0.0.0, nameserver 10.0.0.254.
If everything worked, NetBSD should now be installed on the disk image. Use the following command line to boot the emulated CATS machine:
gxemul -XEcats -d nbsd_cats.img netbsd-GENERIC.aout.gz
It is possible to install and run OpenBSD/cats in GXemul. Unfortunately, "The OpenBSD/cats port was discontinued after the 4.0 release" according to http://www.openbsd.org/cats.html, so from a security perspective it is not up to date, but it is still possible to run for experimental purposes.
To install OpenBSD/cats onto an emulated harddisk image, follow these instructions:
dd if=/dev/zero of=obsd_cats.img bs=1024 count=1 seek=1900000
wget -np -l 0 -r https://ftp.nluug.nl/OpenBSD/4.0/cats/ cp ftp.nluug.nl/OpenBSD/4.0/cats/bsd . cp ftp.nluug.nl/OpenBSD/4.0/cats/bsd.rd .(Replace ftp.se.openbsd.org with a server closer to you, for increased download speed.)
mkisofs -allow-lowercase -o openbsd_cats_4.0.iso ftp.nluug.nl/OpenBSD/ rm -rf ftp.nluug.nl (this directory is not needed anymore)
gxemul -XEcats -d obsd_cats.img -d openbsd_cats_4.0.iso bsd.rdand proceed like you would do if you were installing OpenBSD on a real CATS. (Install onto wd0, don't configure the network, install from CD.)
(Although it is possible to configure the network, IPv4 address 10.0.0.1, netmask 255.0.0.0, gateway/default route 10.0.0.254, and nameserver 10.0.0.254, the userland NAT-like networking layer is not stable enough yet to support a full install via ftp.)
NOTE: Make sure that you sync and reboot correctly once the installation is finished, or the /dev nodes may not have been written correctly to disk.
Once the install has finished, the following command should let you boot from the harddisk image:
gxemul -XEcats -d obsd_cats.img bsd
Debian GNU/Linux for CATS (ARM) could potentially run in GXemul, however:
THIS DOES NOT WORK YET!
The following installation instructions would theoretically work:
dd if=/dev/zero of=debian_cats.img bs=1024 count=1 seek=3300000
http://ftp.debian.org/debian/dists/oldstable/main/disks-arm/current/cats/tftpboot.img
gxemul -XEcats -d debian_cats.img tftpboot.img
It doesn't work, though, because the NIC isn't working well enough.
The only use of Debian/CATS in the emulator right now is as a way to manipulate Linux disk images, if you are on a non-Linux host. By choosing "Execute a shell" in the installer's menu, you can have access to tools such as fdisk and mke2fs, which are useful for creating Linux paritions on disk images.