EBC Exercise 19 DSS2 and sysfs

Here are some example DSS2 sysfs commands that run on the Beagle xM running the 3.2 kernel. (No BeagleBone Black version yet.)

Play around and see what you can learn.

Framebuffers
The framebuffers are in /sys/class/graphics/. beagle$ ls -F /sys/class/graphics/ fb0@ fb1@  fb2@  fbcon@ beagle$ cd /sys/class/graphics/fb0 beagle$ ls -F bits_per_pixel dev      modes            pan        rotate_type  subsystem@ blank          device@  name             phys_addr  size         uevent console        mirror   overlays         power/     state        virt_addr cursor         mode     overlays_rotate  rotate     stride       virtual_size

Overlays, Managers and Displays
The overlays, managers and displays are in /sys/devices/platform/omapdss/ beagle$ cd /sys/devices/platform/omapdss/ beagle$ ls -F display0@ manager1/                     overlay0/  subsystem@ display1@ microamps_requested_vdda_dac  overlay1/  uevent driver@   microamps_requested_vdds_dsi  overlay2/ manager0/ modalias                      power/

beagle$ cd overlay0 beagle$ ls -F enabled      input_size  name         position global_alpha manager     output_size  screen_width beagle$ cat position 0,0 beagle$ cat manager lcd beagle$ cat output_size 640,480

Investigate mplayer
Load Big Buck Bunny. This took some 3 minutes for me. beagle$ cd exercises/gstreamer beagle$ git clone git://github.com/MarkAYoder/esc-media.git beagle$ cd esc-media

Now, start Big Buck Bunny and discover how it uses DSS beagle$ mplayer BigBuckBunny_640x360.m4v beagle$ cd /sys/devices/platform/omapdss beagle$ ls beagle$ cd overlay0 beagle$ cat enabled Repeat for overlay1 and 2, Which are being used? cd to it.

Play with scale and position
beagle$ cd /sys/devices/platform/omapdss/overlay2 beagle$ cat position beagle$ echo 100,100 > position beagle$ cat output_size beagle$ echo 320,400 > output_size

Try transparency beagle$ echo 127 > global_alpha beagle$ cd ../manager0 beagle$ echo 1 > alpha_blending_enabled beagle$ echo 1 > trans_key_enabled beagle$ echo 65535 > trans_key_value Caution: You may have to disable an overlay before changing some values. beagle$ echo “0” > $ovl0/enabled

Assignment
Note what you have learned in a short memo.

Challenge
Can you get mplayer to appear in two windows?