[Asus Transformer TF701] Geometry:
highly experimental: KDE framework 5 (Kubuntu 15.04) rootfs

So it turns out that even the latest KDE framework 5 can be made to work on our tf701t, although with quite some effort.

Download the rootfs here. To install extract to "/data/media/linuxroot". Boot using fastboot and the boot image "boot-media-linuxroot-17.img" from the previous post. After booting, the GUI does not start, but you are greeted with a console login prompt. As usual, the standard user is "ubuntu" with password "ubuntu", real name "Test User". After logging into the console start the GUI as follows:

$ sudo service sddm start

what works:

Compared to Kubuntu 14.04, the good news is that there is no left click bug.

Also, wifi, bluetooth, touch screen seem to work. I have not properly tested suspend.

what does not work:

OpenGL with kwin does not work. Switching it on in Settings for "Display and Monitor" - "Compositor" - "Rendering backend" crashes kwin. This will happen the first time you start the system. because OpenGL is the default. Try to switch to "XRender" so at least some desktop effects work.

Also the system is generally less stable, including kwin and kdeinit5 crashing occasionaly.

Preparing this rootfs was a bit more work than that for Kubuntu 14.04. In the following I only describe the differences to the procedure for Kubuntu 14.04. Everything esle, including the kernel, is the same. Firstly, starting with 15.05 Ubuntu is using systemd instead of upstart. Unfortunately, systemd does not seem to work for us. Maybe it is a simple configuration issue or maybe a more serious problem of incompatbility with the old 3.4 kernel we are using. Fortunately, Canonical has provided a simple way to switch back to upstart for 15.04, by installing the package "upstart-sysv". With that problem sorted, the main challenge was to make Kubuntu 15.04 work with the old 13.04 xserver that we have to use because the tegra driver supports only abi up to version 13 (and 14, but that is buggy). So in addition to the special xserver packages that have to be installed for Xubuntu/Kubuntu 14.04, there are a number of additional packages, mostly from Ubuntu 14.04. To see what these are, have a look at the "/install" directory in the rootfs. A related problem was that the "kubuntu-desktop" package depends on a recent version of the "xorg" package that we cannot use. But "kubuntu-desktop" is only a metapackage and not really required. To get all the other dependencies and recommended packaes anyway I simply put the long list of these in a little shell script "kubuntu-15.04-inst.sh" in the "/install" directoy. So starting this script does the same as installing "kubuntu-desktop", except it does not require the recent "xorg" package. There is one more difference to Xubuntu/Kubuntu 14.04: Kubuntu 15.04 uses sddm as dispaly manager and not lightdm. This means that we need a fix for the display brightness issue for sddm. Fortunately, this turns out to be as easy as for lightdm. Just create a file "/etc/sddm.conf" with the following content:

[Users]
MaximumUid=8999
MinimumUid=5000

[XDisplay]
DisplayCommand=/usr/bin/restore_brightness

This also makes sure that the Android system users are not shown. This file is already included in the rootfs.

In any case and despite of the problems, Kubuntu 15.04, including sddm, looks really good on the tf701t, adapting well to the high DPI. However, the GUI seems to be not as configurable as Kubuntu 14.04.