Using Bitmap::dynamicBitmapCreateExternal

[Priyank]

Hi, I am trying to create an external dynamic bitmap to display an image already loaded into Memory Mapped External Flash. 

uint16_t FrontendApplication::getLogoBitmapId()
{
    if (bitmapId == touchgfx::BITMAP_INVALID)
    {
    	bitmapId = Bitmap::dynamicBitmapCreateExternal(185, 43,(void const*)0x90FC0000, Bitmap::RGB565);
    }
    return bitmapId;
}

void LandingView::setupScreen()
{
    LandingViewBase::setupScreen();
    auto app = static_cast<FrontendApplication*>(Application::getInstance());
    uint16_t bmpId = app->getLogoBitmapId();
    logo.setBitmap(Bitmap(bmpId));
    add(logo);
    logo.invalidate();
}

 I keep getting the bitmapId as BITMAP_INVALID. I've tried the external bitmap function with L8 as well.