Installing Debian Etch on a simulated DECstation using GXemul

I wrote this before etch release and have not kept this page up to date since. You may be interested to know that etch has official support for QEMU, see Aurelien Jarno's page for details.

Install GXemul

apt-get install gxemul - or get it from

Get Debian Etch installation image

Get a mipsel image from

I used the etch beta3 release netinst CD image.

Build (or get) a custom kernel

For some reason I've been unable to run the Debian provided kernels within GXemul - they crash soon after booting. This seems to be an issue with the serial driver in Debian's kernel, thought there might be other issues too. Anyway, I've been able to install using a custom kernel.

If you already have a mips system you can follow these instructions:

Otherwise, get and unzip my compiled image from

Patch the initrd filesystem into the custom kernel

The custom kernel contains a dummy initrd image. The idea is that before booting it, you replace the dummy image with something useful - such as the Debian installer initrd image for example. The initrd you use must be smaller than the dummy initrd, but I made the dummy initrd 8MB which should be plenty enough.

First locate the offset where the dummy initrd data was placed: hd vmlinux- | grep 'foo bar' (In Debian, hd is part of the bsdmainutils package). In my kernel, the initrd data starts at offset 0x001df000 = 1961984

Mount the Debian iso image and make a copy of /boot/initrd.gz

Copy the install initrd over the custom kernel's dummy initrd: dd if=initrd.gz of=vmlinux- bs=1961984 seek=1 conv=notrunc

Create an empty virtual disk

dd if=/dev/zero of=etch_pmax.img bs=1024 count=1 seek=3300000

Start the emulator

gxemul -X -e3max -M 128 -d etch_pmax.img -d debian-testing-mipsel-netinst.iso vmlinux- -o "DEBCONF_PRIORITY=medium"

At this point, the kernel starts running. It will ponder a little, and then etch installer starts.

Follow the etch installation process

There is not much to note that would be different from installing etch on a physical machine. A few minor poinst worth mentioning however:

After the installation is done, reboot into the installed system

gxemul -X -e3max -M 128 -d etch_pmax.img vmlinux- -o "devfs=nomount root=/dev/sda1"

You now have a working etch installation running on an emulated DECstation. Have fun !


I want to thank: