Raspicam is not supported out of the box on uMate 15.10.3 but I found a reference to use raspistill on Ubuntu:
http://raspberrypi.stackexchange.com/questions/37359/how-to-use-raspistill-on-ubuntu. With some minor hiccups, I was able to get it working on an RPi2 with uMate 15.10.3. Major credit to Cerin (???) on the stackexchange forum. I have copied his work shamelessly with some minor changes:
in case someone else wants to use the Raspberry Pi camera on Ubuntu or any other distro besides Raspbian, here's how you do it.
Enable kernel/firmware settings required by the camera
I had to edit /boot/config.txt manually to insert the following:
sudo base -c "echo 'start_x=1' >> /boot/config.txt"
sudo base -c "echo 'gpu_mem=128' >> /boot/config.txt"
Note, in the Ubuntu ARM image I used, these settings didn't exist in
/boot/config.txt, so I can simply append them. If you've already added
the variables, but with different values, you may need to edit them
instead of appending.
Install rpi-update and update the firmware
If you're using a brand-new RPi, you'll almost certainly need to
update the firmware, because whatever the factory installs is ancient.
curl -L --output /usr/bin/rpi-update https://raw.githubusercontent.com/Hexxeh/rpi-update/master/rpi-update && chmod +x /usr/bin/rpi-update
Note, without these step, I was getting the infamous error:
mmal: mmal_component_create_core: could not find component 'vc.ril.camera'
mmal: Failed to create camera component
mmal: main: Failed to create camera component
mmal: Failed to run camera app. Please check for firmware updates
Install userland binaries (e.g. raspistill)
git clone https://github.com/raspberrypi/userland.git
This did not work as buildme failed...I stupidly ignored and went on.
echo 'PATH=$PATH:/opt/vc/bin\nexport PATH' >> ~/.bash_aliases
echo 'LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/opt/vc/lib\nexport LD_LIBRARY_PATH' >> ~/.bash_aliases
sudo reboot now
After these steps, raspistill -o cam.jpg correctly captured video input for me on a Raspberry Pi 2 running Ubuntu 14.04.
After the above, I was surprised to find that raspivid and raspistil were working fine on my RPi2/uMate. The frame rate is much better than when using my USB microscope with guvcview and it is quite sharp, with much better depth of focus than I had expected. Please forgive my blundering around on this...it worked...by accident.