Installing Debian as an upgrade

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These instructions assume you are starting from build 612 or later, which has support for booting from multiple images. (This started working some time prior to build 612, but I can't be bothered to look up the exact build right now.)

Note that you require Activation_and_Developer_Keys to run unsigned operating systems.

Now, boot into sugar. You are currently running from the system in /versions/run/<build number>, which is a copy-on-write mirror of /versions/pristine/<build number>. We're going to install debian in /versions/pristine/debian. (See Early Boot for details on the OS versioning scheme.)

Note that in recent builds, you can magically get to the results of step 3 below by typing:
# /usr/sbin/olpc-update debian
To get the results of step 5, you can type:
# /usr/sbin/olpc-update debian-big
or
# olpc-update debian/debian-big

Shell script alternative

I have created a shell script which automates all steps 1 and 2. All you have to do is put it on the OLPC and run it. However, it is totally unsafe to run software downloaded from a wiki in this way. I could have put all manner of evil in it. So read it first. --65.75.18.227 00:59, 16 December 2007 (EST)

The script: Installing Debian as an upgrade/script

Step 1: Create debian bootstrap

From an existing debian system, as root (fakeroot won't work, sadly): 

# apt-get install debootstrap
# mkdir mnt
# debootstrap --include=udev,wireless-tools etch mnt http://http.us.debian.org/debian/

Wait awhile. Eventually, you'll have a complete debian bootstrap system in mnt. 

# tar -C mnt -czf xo-debian.tgz .
# /bin/rm -rf mnt

If you don't have a debian system, download a prebuilt xo-debian.tgz here.

Put xo-debian.tgz on a usb key.

Step 2: Install debian bootstrap

From the XO, log in as root on console. Insert usb key. 

# cd /versions/pristine
# mkdir debian ; cd debian
# tar xzf /media/*/xo-debian.tgz
# cp /etc/{hosts,fstab} /versions/pristine/debian/etc/
# cp -r /lib/modules/* /versions/pristine/debian/lib/modules
# cp -r /lib/firmware/* /versions/pristine/debian/lib/firmware
# mkdir -p /versions/pristine/debian/{versions,security,var/cache/apt/cache}
# rm -rf /versions/pristine/debian/boot
# cp -r /boot /versions/pristine/debian

Add a new file /versions/pristine/debian/etc/rcS.d/S00unfreeze.sh: 

#! /bin/sh
mount -t sysfs /sys /sys
echo 0 > /sys/devices/platform/dcon/freeze
umount /sys

and ensure that it is executable 

# chmod a+rx /versions/pristine/debian/etc/rcS.d/S00unfreeze.sh

You also need to use the fix at [1] to make apt work. Use vi or nano to edit files. The fix from the link is quoted below, with some edits and paths adjusted appropriately:

Note: to get around the apt-get jffs2/mmap issue, I added the following line to /versions/pristine/debian/etc/fstab:
 tmpfs   /var/cache/apt/cache  tmpfs defaults 0 0
and created /versions/pristine/debian/etc/apt/apt.conf.d/00-tmpfs-cache with:
 Dir {
  Cache "var/cache/apt/" {
   srcpkgcache "cache/srcpkgcache.bin";
   pkgcache "cache/pkgcache.bin";
  };
 };
Not exactly ideal, but it works for me. It will take apt a little while to rebuild the cache after you reboot, of course. I think you could achieve persistence by copying the files to/from the tmpfs either in startup/shutdown scripts, or maybe pre-/post-invocation hooks in apt (which might have the added benefit of being able to mount/unmount the tmpfs on demand).

Make this the new alternate OS! 

# cd /versions/boot
# rm -rf alt
# ln -s /versions/pristine/debian alt
# cp -rl /versions/pristine/debian /versions/run/debian
# /usr/sbin/setattr -R --iunlink /versions/run/debian

Step 3: Boot into Debian!

Shutdown your XO, then take out your usb key. As documented at Cheat codes, reboot while holding down the 'O' game pad key to switch to the alternate OS (debian!). Reboot again with the 'O' game pad key pressed down to switch back later.

If for some reason this doesn't work for you (it didn't for one anonymous user, on version 650), you can do this manually from OpenFirmware (of course you'll need a devkey for this, to get one go to file:///home/.devkey.html). Once you have a devkey, hit "esc" (upper left) when it says to, to get into OF.
The last OS you booted (currently the OLPC one) will be in nand:\boot, and the "alternate" OS (currently Debian) will be in nand:\boot-alt
To boot to the alternate os, type:
# setenv boot-file ro root=mtd0 rootfstype=jffs2 console=ttyS0,115200 console=tty0 fbcon=font:SUN12x22
# setenv boot-device nand:\boot-alt\vmlinuz
# setenv ramdisk nand:\boot-alt\olpcrd.img
To boot to the default os with this method, just don't enter openfirmware, or just type boot at the OF prompt.

Step 4: Start networking

Just use ifconfig if you've got a supported wired ethernet adapter. To connect to an access point: 

# modprobe usb8xxx
# iwconfig eth0 essid <your-access-point>
# dhclient eth0

(The modprobe command is unnecessary if udev did it's job. You might look at the output to 'lsmod' to check that it's loaded.)

You should also be able to use wifi, my WPA network works fine, once I installed a wpa_supplicant deb from my USB key. iwconfig also sees the mesh device, but I have let to test if it works. One weirdness: my wifi interface is eth5!

Step 5: Install fun stuff

For example: 

# apt-get update
# apt-get install emacs

(aptitude will pull in "recommended" dependencies, which will bloat your system. use apt-get or go to "Options->Dependency Handling" and uncheck "Install Recommended packages automatically" instead.) 

# apt-get install gnome-terminal gdm xserver-xorg-video-fbdev xorg metacity xterm gnome-core

(Don't worry too much about the xserver config -- just take the defaults, we'll fix it in a second.) 

# apt-get remove --purge xfonts-75dpi xserver-xorg-input-wacom xserver-xorg-input-synaptics

Now download [2] and copy it to /etc/X11/xorg.conf.

You'll probably want to use 'adduser' to add a user to the system, too. The 'olpc' user will be handy: 

# addgroup --gid 500 olpc
# adduser --uid 500 --gid 500 olpc

Reboot and voila! Graphical goodness.

Note to other users: I had some troubles getting this to work. In order to get X to work, I used these instructions.

Trivia

The instructions above work ok on a 653 build XO, with the system booting successfully into Debian. In case it wasn't obvious, the system will continue to 'boot alternate' until you switch back to the XO os by once again hitting the 'o' game key while powering up.


Following these instructions one user had to add the write permission for others for /tmp. It was a upgrade from a standard 650 build the default sugar build umask is read+execute for others. Then I could login to the gui.

To preserve this alternate boot even when you olpc-update the main partition, you'll want to do something like: 

# HASH=$(basename $(readlink /versions/running))
# touch /versions/sticky/$HASH

when you're booted into debian. olpc-update will also report the hash if you use the olpc-update method; otherwise following the instructions above the HASH is 'debian'.

If your network device is named something like eth5 and you prefer eth0, empty the file "/etc/udev/rules.d/z25_persistent-net.rules" and reboot. The network devices should be redetected. 

# mv '/etc/udev/rules.d/z25_persistent-net.rules' '/etc/udev/rules.d/z25_persistent-net.rules.old'
# touch '/etc/udev/rules.d/z25_persistent-net.rules'
# reboot

Links

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