fbtest

A simple program to draw a rectangle of fixed color to the Linux frame buffer display. The rectangle will have a border of fixed color, 10 pixels wide.

Used for display driver development.

Cross-compiling

Assuming a Yocto built toolchain

export OETMP=<TMPDIR>
make -f Makefile-cross

The default Makefile-cross assumes a hard-fp built gcc.

Comment the hard-fp line and uncomment the soft-fp line if that's what you have.

Natively compiling

make

Running

root@overo:~# ./fbtest -h

Usage ./fbtest: [-r<red>] [-g<green>] [-b<blue>] [-B<border>]
  All colors default to 0xff
  The border color applies to all rgb and is 10 pixels wide
  If border is not provided, none is drawn.
  The index defaults to 0, if your FB has more than 1 buffers, you can set it.
  If set the index to -1, we will use all buffers for 20 times.

Examples

root@overo:~# ./fbtest
root@overo:~# ./fbtest -r0x40
root@overo:~# ./fbtest -r0x40 -g0 -b0
root@overo:~# ./fbtest -r0x80 -g0 -b0
root@overo:~# ./fbtest -r0xff -g0 -b0
root@overo:~# ./fbtest -r0x40 -g0 -b0
root@overo:~# ./fbtest -r0x40 -g0x40 -b0
root@overo:~# ./fbtest -r0x40 -g0x40 -b0x30
root@overo:~# ./fbtest -r0x40 -g0x40 -b0x30 -B0xaa
root@overo:~# ./fbtest -r0x40 -g0x40 -b0x30 -B0xaa -i -1

Stop the blinking cursor

Kernel command line parameter

vt.global_cursor_default=0

Wake the framebuffer when it blanks

echo 0 > /sys/class/graphics/fb0/blank