Naive color depth questions

Alan Corey alan01346 at
Mon Apr 25 14:51:03 UTC 2016

I have a Raspberry Pi Model B version 2 that I tinker with for
amusement.  Recently I dug it out after sitting a year or so and
loaded the SD card with Raspian Jessie Lite.  The Lite package as it
turns out doesn't include X, so I've been adding it by installing some
X programs I want with apt-get and letting it fill in the
dependencies.  There apparently isn't a clearly defined method for
adding X to Lite, which is mostly for headless use.  Most of the BSDs
are packaged with X in a few packages you install in addition to the
OS if you want it.  When I added the xinit deb I was able to use
startx.  I have an ongoing thread on their forum in the
troubleshooting area:
and somebody said I should also install the raspberrypi-ui-mods deb
which helped quite a bit but I still have strange things happening.

Different programs seem to run at different color depths.  Gimp,
Iceweasel (Firefox), a few others can open photograhs in what looks
like normal 24 (or 32)  bit color.  Other programs like Synaptic and
qiv seem limited.  Qiv shows photos as a black image, Synaptic comes
up with a black panel and white text on it.  The Pi works with a
framebuffer apparently instead of a real video card.  I think it's
shared memory between the GPU and the CPU.

If I do X -configure I get an error that there are no devices to
configure and it lists video drivers fbdev and modesetting.  I seem to
have both installed.  If I run xrandr it fails to get the size of
gamma.  If I run xdpyinfo I see that the root window has a depth of 16
planes.  I see lots of visuals, most of the Truecolor class, toward
the end of the list are some DirectColor.  Most of these are 16
planes, 6 bits per colot.  But at the end is one with 32 planes and 8
bits per color.  It's X server 1.17.2, I don't see any errors in
Xorg.0.log except things like missing font directories.

I guess my question is what's still missing.  To some degree if
they're interested I'd like to help create a package
for adding X to the Raspian Lite distribution (or improve
raspberrypi-ui-mods).  The alternative is a “full desktop” package
with Libre Office, Mathematica, many  other things.  It's a 290 meg
download vs a 1.3 gig one.  I'd like to see an addon to lite to get
basic X with less featureitis.

Credit is the root of all evil.  - AB1JX

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