How to prevent qt(linux) from drawing to black when first run?

[devj]

I used embedded linux (imx6q) with eglfs.
Framebuffer is drawing black screen while starting Qt application.
Simple application is black for 1sec under. Heavy application is for 4~5sec.
This happens only once when first QT run.
How to prevent qt from drawing to black? I can modify kernel or QT sources. any idea?

test source is below.

import QtQuick 2.0

Rectangle {
    id: page
    width: 320; height: 480
    color: "lightgray"

    Text {
        id: helloText
        text: "Hello world!"
        y: 30
        anchors.horizontalCenter: page.horizontalCenter
        font.pointSize: 24; font.bold: true
    }
}