Android p 开机动画显示到HDMI屏上

Android 默认支持在java层两个display 屏幕,
private static final int[] BUILT_IN_DISPLAY_IDS_TO_SCAN = new int[] {
SurfaceControl.BUILT_IN_DISPLAY_ID_MAIN,
SurfaceControl.BUILT_IN_DISPLAY_ID_HDMI,
};
Android P 启动时，会再DisplayManagerService->LocalDisplayAdapter尝试扫描display
我的目的是将开机动画运行在HDMI屏
只需修改frameworks/base/cmds/bootanimation/
1、将所有eDisplayIdMain替换成eDisplayIdHdmi

sp dtoken(SurfaceComposerClient::getBuiltInDisplay(
            ISurfaceComposer::eDisplayIdHdmi));

2、添加.setLayerStack(control, 1) 到如下位置

t.setLayer(control, 0x40000000)
    .setLayerStack(control, 1)
        .apply();

最终将显示到HDMI屏