RK3399ProD toybrick debian10文件系统镜像制作问题

按照wiki的教程 打包debian10的文件系统。制作好镜像烧入启动之后 出现桌面系统无法启动的现象（HDMI显示 屏幕显示内容和串口控制台相同，但无法进入桌面登入界面）
教程连接http://t.rock-chips.com/wiki.php?mod=view&id=112

串口控制台打印信息：


systemctl 查看 lightdm服务启动失败 status信息如下：
lightdm.service - Light Display Manager
   Loaded: loaded (/lib/systemd/system/lightdm.service; indirect; vendor preset: enabled)
   Active: failed (Result: exit-code) since Wed 2020-09-30 07:01:31 UTC; 12min ago
     Docs: man:lightdm(1)
  Process: 958 ExecStartPre=/bin/sh -c [ "$(cat /etc/X11/default-display-manager 2>/dev/null)" = "/usr/sbin/lightdm" ] (code=exited, status=0/SUCCESS)
  Process: 960 ExecStart=/usr/sbin/lightdm (code=exited, status=1/FAILURE)
Main PID: 960 (code=exited, status=1/FAILURE)

Sep 30 07:01:31 debian10.toybrick systemd[1]: lightdm.service: Service RestartSec=100ms expired, scheduling restart.
Sep 30 07:01:31 debian10.toybrick systemd[1]: lightdm.service: Scheduled restart job, restart counter is at 10.
Sep 30 07:01:31 debian10.toybrick systemd[1]: Stopped Light Display Manager.
Sep 30 07:01:31 debian10.toybrick systemd[1]: lightdm.service: Start request repeated too quickly.
Sep 30 07:01:31 debian10.toybrick systemd[1]: lightdm.service: Failed with result 'exit-code'.
Sep 30 07:01:31 debian10.toybrick systemd[1]: Failed to start Light Display Manager.
Sep 30 07:01:31 debian10.toybrick systemd[1]: lightdm.service: Triggering OnFailure= dependencies.

楼主能否帮忙解答下？