Comment 11 for bug 1802950

I didn't get the above steps to work, so I choose a different way.

I've tried to compile the missing "bochs-drm" module by following these steps :

    apt-get install linux-source-4.18.0
    cd /usr/src/linux-source-4.18.0/
    tar xjf linux-source-4.18.0.tar.bz2
    cd linux-source-4.18.0/
    apt-get install bison
    apt-get install flex
    apt-get install libelf-dev
    make oldconfig
    make menuconfig

In the menus I searched and enabled the module CONFIG_DRM_BOCHS=m
Then I launched the compilation :

    make modules
    # Get some coffee
    mkdir /lib/modules/4.18.0-12-generic/kernel/drivers/gpu/drm/bochs
    cp drivers/gpu/drm/bochs/*.ko /lib/modules/4.18.0-12-generic/kernel/drivers/gpu/drm/bochs
    depmod -a
    modprobe bochs-drm

This didn't work and I got the following message in "dmesg" :
bochs_drm: version magic '4.18.17 SMP mod_unload ' should be '4.18.0-12-generic SMP mod_unload '

But I found a way to change it by editing the main Makefile and changing :
    SUBLEVEL = 17
    EXTRAVERSION =
To the values :
    SUBLEVEL = 0
    EXTRAVERSION = -12-generic

Then I restarted a clean compilation :

    make clean
    make modules
    # Get some coffee
    cp drivers/gpu/drm/bochs/*.ko /lib/modules/4.18.0-12-generic/kernel/drivers/gpu/drm/bochs
    depmod -a
    modprobe bochs-drm
    systemctl start sddm

And then I got SDDM back on screen !

I hope bochs-drm will be included in future standard kernel, as asked for in bug 1795857, because these steps will be necessary after each update of the standard kernel.