1.3 KiB
Experimenting with multiple roots
$ qemu-img create debian.img 600M $ mkfs.ext2 debian.img $ mkdir debian-mnt $ mount -o loop debian.img debian-mnt $ debootstrap wheezy debian-mnt $ chroot debian-mnt $ apt-get install linux-image-3.0.0 Control-d $ cp debian-mnt/boot/vmlinuz* . $ cp debian-mnt/boot/initrd* . $ umount debian-mnt
You now have a Debian disk image in debian.img and a kernel+initrd that are bootable with qemu.
Modifying the image
The first thing I did was re-mount the image, and move almost everythig (/boot, /var, /etc), except lost+found to a new directory "r0".
Then I started hacking on the initrd, making understand how to chroot to "r0".
This means that after booting, every process would be in /r0 - including any hacktree process. Assuming objects live in say /objects, we need some way for hacktree to switch things. I think just chroot breakout would work. This has the advantage the daemon can continue to use libraries from the active host.
Note there is a self-reference here (as is present in Debian/Fedora etc.) - the update system would at present be shipped with the system itself. Should they be independent? That has advantages and disadvantages. I think we should just try really really hard to avoid breaking hacktree in updates.