giving s/390 a try

Note: This is an old blog entry. It was turned into some more up-to-date documentation that is part of Debian's hercules package, in /usr/share/doc/hercules/giving_s_390_a_try.html

It turns out to be suprisingly easy to install debian s/390 in hercules using d-i. At least I didn't know anything about s390 and I got it to work. And it's suprisingly fast at most things. Quick howto:

Make sure you're running a 2.4 kernel, hercules does not work with 2.6 (#241064).
Install hercules.
See README.Debian about virtual networking perms. I added a tun group, put myself in that group, made /usr/bin/hercifc suid and executable only by that group, and made /dev/net/tun writable by the group. Also, be sure to echo 1 > /proc/sys/net/ipv4/ip_forward and make sure hercules will be able to get to the internet.
Download installer-s390/images/current/generic/* from unstable or testing.

Make a hercules.cnf in the same directory:

CPUSERIAL   002623
CPUMODEL    3090
MAINSIZE    64
CODEPAGE    default
XPNDSIZE    0
#CNSLPORT   3270
#HTTPPORT   8081 noauth userid password
#HTTPROOT   /usr/share/hercules/
NUMCPU      1
LOADPARM    0120....
OSTAILOR    LINUX
PANRATE     SLOW
ARCHMODE    ESA/390

000C    3505    kernel.debian parmfile.debian initrd.debian autopad eof
0120    3390    dasd0
0A00    3088    CTCI /dev/net/tun 1500 192.168.42.1 192.168.42.2 255.255.255.0
0A01    3088    CTCI /dev/net/tun 1500 192.168.42.1 192.168.42.2 255.255.255.0

Create the dasd (disk) image. This will make a 900 mb one: dasdinit dasd0 3390-1 root
Start hercules. Type "ipl c" to boot d-i from the emulated card deck. (Old-skool! I'd pay good money to see d-i boot from a REAL card deck ;-)
The answers to the first 6 questions about networking are ".1", ".1", ".1", ".2", ".192.168.42.1", ".192.168.42.2". Note the dots in front pass the line on to d-i. Note that you can use ". " if it asks you to press enter.
Continue with rest of networking setup and ssh setup. Key generation will take a while.
After ssh setup is complete you can ssh to installer@192.168.42.1 and continue the installation in a nicer UI, which from here on is the same as any d-i run.
Except for partitioning. You get to use a command line fdisk program, and before that you may encounter a loop at disk initialization (bug #281407).
To reboot, type "stop" at the hercules Command prompt, and then "ipl 120" to boot from the dasd.
ssh back into the installed system and it'll run base-config for you, rest of the install is same old same old.
Now save this image and use it for s390 development work.. and now that you have a s390 development system and know how to use the debian installer, why not contribute some time to making the d-i s390 installer a little more polished..

I need to get an ipaq, just so I can have a s/390 in my pocket.