c++ - Qt hello world example does not display anything on LCD -

i have colibri evaluation board 3.1a tegra 2 on it. have compiled qt library , copied board. trying simple hello world button app. program runs fine(confirmed inserting prints), dont on lcd display.

this simple code trying

qapplication a( argc, argv );  qpushbutton hello( "hello world!", 0 ); hello.resize( 100, 30 );  a.setmainwidget( &hello ); hello.show(); return a.exec(); 

make sure use -qws flag:

./myapp -qws