树莓派4启动不了ubuntu桌面

在安装ubutun server 12.04后，通过命令安装gnome桌面：

sudo apt-get install --no-install-recommends ubuntu-desktop

安装完成重启后，桌面仍然进入不了，检查xorg日志显示如下错误：

 (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
[    49.223] (EE) Failed to load module "fbdev" (module does not exist, 0)
[    49.227] (EE) Failed to load module "fbdev" (module does not exist, 0)
[    49.227] (EE) open /dev/dri/card0: No such file or directory
[    49.227] (EE) open /dev/dri/card0: No such file or directory
[    49.227] (EE) No devices detected.
[    49.227] (EE)
[    49.228] (EE) no screens found(EE)
[    49.228] (EE)
[    49.228] (EE) Please also check the log file at "/home/ubuntu/.local/share/xorg/Xorg.0.log" for additional information.
[    49.228] (EE)
[    49.236] (EE) Server terminated with error (1). Closing log file.

经过检查，发现是缺少fbdev driver, 安装后解决问题:

sudo apt install xserver-xorg-video-fbdev