Hack-A-N900/Unionfs

EXPERIMENTAL: You need to read and understand the chroot-unionfs.sh script.

Update Kernel

Add tesing repositories to /etc/apt/sources.list:

 deb http://repository.maemo.org/extras/ fremantle free
 deb-src http://repository.maemo.org/extras/ fremantle free
 
 deb http://repository.maemo.org/extras-testing/ fremantle free  
 deb-src http://repository.maemo.org/extras-testing/ fremantle free

apt-get update

apt-get install kernel-flasher-maemo kernel-modules-maemo

cross your thumbs now.. (you backed up before right?)

reboot

WELCOME TO YOUR UPDATED SYSTEM THAT SUPPORTS UNIONFS \o/!

Create unionfs / chroot overlay filesystem for development

Create a 2 GB file on /home/user/MyDocs/sandbox/fs.img

 mkdir /home/user/MyDocs/sandbox/
 cd /home/user/MyDocs/sandbox/
 dd if=/dev/zero of=fs.img bs=1M count=1 seek=2048
 mkfs.ext2 fs.img

Get the shiny overlay/chroot shellscript

 wget http://metalab.at/wiki/images/d/d8/Chroot-unionfs.sh  WARNING the link might be different now look here: Datei:Chroot-unionfs.sh
 mv chroot-unionfs.sh /sbin/chroot-unionfs
 chmod +x /sbin/chroot-unionfs

This script doeas some magic including

• loading the dm-loop kernel module (for /dev/loop? devices)
• overlaying the unionfs filesystem
• mounting all needed filesystem folders inside the unionfs
• chroot()'ing inside

It is started like this:

bash /sbin/chroot-unionfs -v -t /home/user/MyDocs/sandbox/fs.img

Read the source to find out about command line parameters like -t for testing and others..

If this script is successful you should find yourself in a chrooted environment inside the unionfs

touch /CHROOTED
ls /CHROOTED    # it should be here!
exit
 ls /CHROOTED   # it should be gone!