Framebuffer
From ArmadeusWiki
On this page you will find usefull informations to have a working Linux Framebuffer on your board.
Contents
Kernel configuration
Framebuffer is already configured (for Microtips LCD) in standard/default Armadeus kernel image
- launch Linux kernel configuration:
[armadeus]$ make linux-menuconfig
- in "Char Devices" menu, activate "Virtual Terminal" and "Support for virtual terminal on console"
- activate Device drivers -> Graphic support -> Support for Framebuffer -> Motorola iMX LCD support and choose your LCD in LCD Panel
- "Console display driver support ->Frame buffer console
support" (deactivate VGA stuff & add some fonts), then choose 224 colour boot logo
- recompile the kernel:
[armadeus]$ make linux
- , now to have console on serial port, you will have to add "console=ttySMX0,115200n8" to your boot parameters
- reflash kernel image on your board and enjoy (you should see Linux logo on screen at startup)!
Userland
If you have devfs activated, framebuffer device can be accessed with /dev/fb/0. Otherwise, you will need to create the device node with
# mknod c 29 0
You can activate some test tools from the armadeus build process:
$ make menuconfig -> packages -> fbset
You have several test tools on yahoo groups to play a little with the framebuffer.
Tips
- To stop blinking cursor:
# echo 0 > /sys/class/graphics/fbcon/cursor_blink
or
# echo -e '\033[?17;0;0c' > /dev/tty0
- To grab a screenshot of a running Framebuffer application, use FBGrab
- To activate Framebuffer low power mode:
# echo 1 > /sys/class/graphics/fb0/blank
- To leave Framebuffer low power mode:
# echo 0 > /sys/class/graphics/fb0/blank
