如何启动 xrdp 会话和 startx ？我正在尝试：
- 停止 lightdm
- 登录到 xrdp（使用显示：10）
- 从 tty1，startx --:1
但是 Xorg 无法启动并出现错误（~/.local/share/xorg/Xorg.1.log）：
[ 2231.947] (II) FBDEV: driver for framebuffer: fbdev
[ 2231.947] (II) VESA: driver for VESA chipsets: vesa
[ 2231.949] xf86EnableIOPorts: failed to set IOPL for I/O (Operation not permitted)
...
Fatal server error:
[ 2231.950] (EE) Cannot run in framebuffer mode. Please specify busIDs for all framebuffer devices
/dev/fb0 已存在，我不知道是否应该创建另一个。
完整日志：
[ 2231.901]
X.Org X Server 1.19.6
Release Date: 2017-12-20
[ 2231.907] X Protocol Version 11, Revision 0
[ 2231.907] Build Operating System: Linux 4.15.0-115-generic x86_64 Ubuntu
[ 2231.909] Current Operating System: Linux ubuntu 4.15.0-122-generic #124-Ubuntu SMP Thu Oct 15 13:03:05 UTC 2020 x86_64
[ 2231.909] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-4.15.0-122-generic root=/dev/mapper/xubuntu--vg-root ro quiet splash
[ 2231.912] Build Date: 04 September 2020 03:34:39PM
[ 2231.913] xorg-server 2:1.19.6-1ubuntu4.6 (For technical support please see http://www.ubuntu.com/support)
[ 2231.914] Current version of pixman: 0.34.0
[ 2231.916] Before reporting problems, check http://wiki.x.org
to make sure that you have the latest version.
[ 2231.916] Markers: (--) probed, (**) from config file, (==) default setting,
(++) from command line, (!!) notice, (II) informational,
(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
[ 2231.919] (==) Log file: "/home/user/.local/share/xorg/Xorg.1.log", Time: Tue Oct 27 10:39:15 2020
[ 2231.921] (==) Using system config directory "/usr/share/X11/xorg.conf.d"
[ 2231.921] (==) No Layout section. Using the first Screen section.
[ 2231.921] (==) No screen section available. Using defaults.
[ 2231.921] (**) |-->Screen "Default Screen Section" (0)
[ 2231.921] (**) | |-->Monitor "<default monitor>"
[ 2231.921] (==) No monitor specified for screen "Default Screen Section".
Using a default monitor configuration.
[ 2231.921] (==) Automatically adding devices
[ 2231.921] (==) Automatically enabling devices
[ 2231.921] (==) Automatically adding GPU devices
[ 2231.921] (==) Automatically binding GPU devices
[ 2231.921] (==) Max clients allowed: 256, resource mask: 0x1fffff
[ 2231.921] (WW) The directory "/usr/share/fonts/X11/cyrillic" does not exist.
[ 2231.921] Entry deleted from font path.
[ 2231.921] (WW) The directory "/usr/share/fonts/X11/100dpi/" does not exist.
[ 2231.921] Entry deleted from font path.
[ 2231.921] (WW) The directory "/usr/share/fonts/X11/75dpi/" does not exist.
[ 2231.921] Entry deleted from font path.
[ 2231.921] (WW) The directory "/usr/share/fonts/X11/100dpi" does not exist.
[ 2231.921] Entry deleted from font path.
[ 2231.921] (WW) The directory "/usr/share/fonts/X11/75dpi" does not exist.
[ 2231.921] Entry deleted from font path.
[ 2231.921] (==) FontPath set to:
/usr/share/fonts/X11/misc,
/usr/share/fonts/X11/Type1,
built-ins
[ 2231.921] (==) ModulePath set to "/usr/lib/xorg/modules"
[ 2231.921] (II) The server relies on udev to provide the list of input devices.
If no devices become available, reconfigure udev or disable AutoAddDevices.
[ 2231.921] (II) Loader magic: 0x5566ce4c0020
[ 2231.921] (II) Module ABI versions:
[ 2231.921] X.Org ANSI C Emulation: 0.4
[ 2231.921] X.Org Video Driver: 23.0
[ 2231.921] X.Org XInput driver : 24.1
[ 2231.921] X.Org Server Extension : 10.0
[ 2231.922] (++) using VT number 1
[ 2231.933] (II) systemd-logind: took control of session /org/freedesktop/login1/session/_31
[ 2231.934] (II) xfree86: Adding drm device (/dev/dri/card0)
[ 2231.935] (II) systemd-logind: got fd for /dev/dri/card0 226:0 fd 11 paused 1
[ 2231.935] (EE) Error systemd-logind returned paused fd for drm node
[ 2231.935] (II) systemd-logind: releasing fd for 226:0
[ 2231.945] (--) PCI:*(0:0:2:0) 80ee:beef:0000:0000 rev 0, Mem @ 0xe0000000/16777216, BIOS @ 0x????????/131072
[ 2231.945] (II) LoadModule: "glx"
[ 2231.945] (II) Loading /usr/lib/xorg/modules/extensions/libglx.so
[ 2231.946] (II) Module glx: vendor="X.Org Foundation"
[ 2231.946] compiled for 1.19.6, module version = 1.0.0
[ 2231.946] ABI class: X.Org Server Extension, version 10.0
[ 2231.946] (==) Matched vboxvideo as autoconfigured driver 0
[ 2231.946] (==) Matched modesetting as autoconfigured driver 1
[ 2231.946] (==) Matched fbdev as autoconfigured driver 2
[ 2231.946] (==) Matched vesa as autoconfigured driver 3
[ 2231.946] (==) Assigned the driver to the xf86ConfigLayout
[ 2231.946] (II) LoadModule: "vboxvideo"
[ 2231.946] (WW) Warning, couldn't open module vboxvideo
[ 2231.946] (II) UnloadModule: "vboxvideo"
[ 2231.946] (II) Unloading vboxvideo
[ 2231.946] (EE) Failed to load module "vboxvideo" (module does not exist, 0)
[ 2231.946] (II) LoadModule: "modesetting"
[ 2231.946] (II) Loading /usr/lib/xorg/modules/drivers/modesetting_drv.so
[ 2231.947] (II) Module modesetting: vendor="X.Org Foundation"
[ 2231.947] compiled for 1.19.6, module version = 1.19.6
[ 2231.947] Module class: X.Org Video Driver
[ 2231.947] ABI class: X.Org Video Driver, version 23.0
[ 2231.947] (II) LoadModule: "fbdev"
[ 2231.947] (II) Loading /usr/lib/xorg/modules/drivers/fbdev_drv.so
[ 2231.947] (II) Module fbdev: vendor="X.Org Foundation"
[ 2231.947] compiled for 1.19.3, module version = 0.4.4
[ 2231.947] Module class: X.Org Video Driver
[ 2231.947] ABI class: X.Org Video Driver, version 23.0
[ 2231.947] (II) LoadModule: "vesa"
[ 2231.947] (II) Loading /usr/lib/xorg/modules/drivers/vesa_drv.so
[ 2231.947] (II) Module vesa: vendor="X.Org Foundation"
[ 2231.947] compiled for 1.19.3, module version = 2.3.4
[ 2231.947] Module class: X.Org Video Driver
[ 2231.947] ABI class: X.Org Video Driver, version 23.0
[ 2231.947] (==) Matched vboxvideo as autoconfigured driver 0
[ 2231.947] (==) Matched modesetting as autoconfigured driver 1
[ 2231.947] (==) Matched fbdev as autoconfigured driver 2
[ 2231.947] (==) Matched vesa as autoconfigured driver 3
[ 2231.947] (==) Assigned the driver to the xf86ConfigLayout
[ 2231.947] (II) LoadModule: "vboxvideo"
[ 2231.947] (WW) Warning, couldn't open module vboxvideo
[ 2231.947] (II) UnloadModule: "vboxvideo"
[ 2231.947] (II) Unloading vboxvideo
[ 2231.947] (EE) Failed to load module "vboxvideo" (module does not exist, 0)
[ 2231.947] (II) LoadModule: "modesetting"
[ 2231.947] (II) Loading /usr/lib/xorg/modules/drivers/modesetting_drv.so
[ 2231.947] (II) Module modesetting: vendor="X.Org Foundation"
[ 2231.947] compiled for 1.19.6, module version = 1.19.6
[ 2231.947] Module class: X.Org Video Driver
[ 2231.947] ABI class: X.Org Video Driver, version 23.0
[ 2231.947] (II) UnloadModule: "modesetting"
[ 2231.947] (II) Unloading modesetting
[ 2231.947] (II) Failed to load module "modesetting" (already loaded, 0)
[ 2231.947] (II) LoadModule: "fbdev"
[ 2231.947] (II) Loading /usr/lib/xorg/modules/drivers/fbdev_drv.so
[ 2231.947] (II) Module fbdev: vendor="X.Org Foundation"
[ 2231.947] compiled for 1.19.3, module version = 0.4.4
[ 2231.947] Module class: X.Org Video Driver
[ 2231.947] ABI class: X.Org Video Driver, version 23.0
[ 2231.947] (II) UnloadModule: "fbdev"
[ 2231.947] (II) Unloading fbdev
[ 2231.947] (II) Failed to load module "fbdev" (already loaded, 0)
[ 2231.947] (II) LoadModule: "vesa"
[ 2231.947] (II) Loading /usr/lib/xorg/modules/drivers/vesa_drv.so
[ 2231.947] (II) Module vesa: vendor="X.Org Foundation"
[ 2231.947] compiled for 1.19.3, module version = 2.3.4
[ 2231.947] Module class: X.Org Video Driver
[ 2231.947] ABI class: X.Org Video Driver, version 23.0
[ 2231.947] (II) UnloadModule: "vesa"
[ 2231.947] (II) Unloading vesa
[ 2231.947] (II) Failed to load module "vesa" (already loaded, 0)
[ 2231.947] (II) modesetting: Driver for Modesetting Kernel Drivers: kms
[ 2231.947] (II) FBDEV: driver for framebuffer: fbdev
[ 2231.947] (II) VESA: driver for VESA chipsets: vesa
[ 2231.949] xf86EnableIOPorts: failed to set IOPL for I/O (Operation not permitted)
[ 2231.950] (WW) Falling back to old probe method for modesetting
[ 2231.950] (II) modeset(1): using default device
[ 2231.950] (II) Loading sub module "fbdevhw"
[ 2231.950] (II) LoadModule: "fbdevhw"
[ 2231.950] (II) Loading /usr/lib/xorg/modules/libfbdevhw.so
[ 2231.950] (II) Module fbdevhw: vendor="X.Org Foundation"
[ 2231.950] compiled for 1.19.6, module version = 0.0.2
[ 2231.950] ABI class: X.Org Video Driver, version 23.0
[ 2231.950] (**) FBDEV(2): claimed PCI slot 0@0:2:0
[ 2231.950] (II) FBDEV(2): using default device
[ 2231.950] (WW) Falling back to old probe method for vesa
[ 2231.950] (WW) VGA arbiter: cannot open kernel arbiter, no multi-card support
[ 2231.950] (EE) Screen 0 deleted because of no matching config section.
[ 2231.950] (II) UnloadModule: "modesetting"
[ 2231.950] (EE)
Fatal server error:
[ 2231.950] (EE) Cannot run in framebuffer mode. Please specify busIDs for all framebuffer devices
[ 2231.950] (EE)
[ 2231.950] (EE)
Please consult the The X.Org Foundation support
at http://wiki.x.org