EBC Exercise 19 DSS2 and sysfs

Here are some example DSS2 sysfs commands. 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
Start BigBuckBunny and discover how it uses DSS 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.