[Buildroot] Buildroot enhancement proposal: on starting a GUI service at boot

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Angelo,

On Wed, 15 Jul 2015 17:21:13 +0200, Angelo Compagnucci wrote:
> One of the common use-case for an embedded system is to start a gui at
> boot. Probably it will be the main point of interaction after all and
> the most sensitive process in the whole system.
> 
> I'm thinking on adding a custom option to set correctly a gui service
> to be started at boot, something that will make easier for a buildroot
> user to start a custom gui service at boot instead of fighting with
> overlay and service scipts/files.
> 
> Note that this gui service is different from a standard service: it
> should be respawned if someting goes wrong and this cannot be done in
> a normal busybox/systemv init script: for busybox/systemv it should be
> added directly to /etc/inittab.
> 
> Actually I'm more oriented in adding an option into "System
> configuration": a string that will contain the command line to be
> added as a service. The matter is to individuate which init system is
> in use and acting accordingly: adding a line in /etc/inittab for
> busybox and systemv or adding a service file for systemd.
> 
> Aside from technical difficulty which is none, what could be the best
> way to implement such behaviour? Is it a desirable feature for
> buildroot?
> If yes, what is the best approach to have it accepted, a "package", an
> option, where?

I don't really understand what would be the usefulness of such a thing.
The mechanism to start a "GUI service" highly depends on which
graphical library you're using. Starting a Qt on framebuffer
application will be very different from starting an application under
X.org.

To me, this is exactly the sort of things that is so system-specific
that it belongs to a project-specific rootfs overlay. You're saying
"fighting with overlay and service scripts/files", but I don't really
see where a "fight" is needed. A rootfs overlay is dead simple to us,
and if a Buildroot user is not capable of using a rootfs overlay, he
will probably not be capable of doing lots of other tasks/tweaks needed
to get his embedded Linux system running correctly.

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com