问题
I am hosting Ubuntu 16.04 on Virtual Box from Windows 10. Inside that Ubuntu 16.04, there is QEmu emulating ARM processor, running Ubuntu Trusty (14.04).
When I start QEmu as follows, it shows a window with title QEMU, but completely black client area:
qemu-system-arm -smp 2 --drive format=raw,if=sd,file=vexpress-8G.img -kernel vmlinuz-3.13.0-24-generic-lpae -initrd initrd.img-3.13.0-24-generic-lpae -M vexpress-a15 -serial stdio -m 2048 -append 'root=/dev/mmcblk0 rw mem=2048M raid=noautodetect rootwait console=ttyAMA0,38400n8 devtmpfs.mount=0' -dtb ./vexpress-v2p-ca15-tc1.dtb
The console of the guest OS (ARM-Ubuntu) works, boot messages are displayed in the same terminal where qemu-system-arm command has been run. But when I type startx command, it shows errors:
Loading extension GLX
(EE)
Fatal server error:
(EE) no screens found(EE)
(EE)
Please consult the The X.Org Foundation support
at http://wiki.x.org
for help.
(EE) Please also check the log file at "/var/log/Xorg.0.log" for additional information.
(EE)
(EE) Server terminated with error (1). Closing log file.
xinit: giving up
xinit: unable to connect to X server: Connection refused
xinit: server error
/var/log/Xorg.0.log contains the following:
[ 214.406]
X.Org X Server 1.15.1
Release Date: 2014-04-13
[ 214.411] X Protocol Version 11, Revision 0
[ 214.411] Build Operating System: Linux 3.2.0-58-highbank armv7l Ubuntu
[ 214.412] Current Operating System: Linux VM-Ubuntu1 3.13.0-24-generic-lpae #46-Ubuntu SMP Thu Apr 10 21:01:14 UTC 2014 armv7l
[ 214.413] Kernel command line: root=/dev/mmcblk0 rw mem=2048M raid=noautodetect rootwait console=ttyAMA0,38400n8 devtmpfs.mount=0
[ 214.416] Build Date: 16 April 2014 01:41:53PM
[ 214.417] xorg-server 2:1.15.1-0ubuntu2 (For technical support please see http://www.ubuntu.com/support)
[ 214.418] Current version of pixman: 0.30.2
[ 214.418] Before reporting problems, check http://wiki.x.org
to make sure that you have the latest version.
[ 214.419] Markers: (--) probed, (**) from config file, (==) default setting,
(++) from command line, (!!) notice, (II) informational,
(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
[ 214.431] (==) Log file: "/var/log/Xorg.0.log", Time: Fri Aug 19 16:21:42 2016
[ 214.446] (==) Using system config directory "/usr/share/X11/xorg.conf.d"
[ 214.461] (==) No Layout section. Using the first Screen section.
[ 214.462] (==) No screen section available. Using defaults.
[ 214.463] (**) |-->Screen "Default Screen Section" (0)
[ 214.463] (**) | |-->Monitor "<default monitor>"
[ 214.468] (==) No monitor specified for screen "Default Screen Section".
Using a default monitor configuration.
[ 214.470] (==) Automatically adding devices
[ 214.471] (==) Automatically enabling devices
[ 214.471] (==) Automatically adding GPU devices
[ 214.475] (WW) The directory "/usr/share/fonts/X11/cyrillic" does not exist.
[ 214.476] Entry deleted from font path.
[ 214.476] (WW) The directory "/usr/share/fonts/X11/100dpi/" does not exist.
[ 214.477] Entry deleted from font path.
[ 214.478] (WW) The directory "/usr/share/fonts/X11/75dpi/" does not exist.
[ 214.478] Entry deleted from font path.
[ 214.479] (WW) The directory "/usr/share/fonts/X11/100dpi" does not exist.
[ 214.479] Entry deleted from font path.
[ 214.480] (WW) The directory "/usr/share/fonts/X11/75dpi" does not exist.
[ 214.480] Entry deleted from font path.
[ 214.481] (==) FontPath set to:
/usr/share/fonts/X11/misc,
/usr/share/fonts/X11/Type1,
built-ins
[ 214.482] (==) ModulePath set to "/usr/lib/arm-linux-gnueabihf/xorg/extra-modules,/usr/lib/xorg/extra-modules,/usr/lib/xorg/modules"
[ 214.484] (II) The server relies on udev to provide the list of input devices.
If no devices become available, reconfigure udev or disable AutoAddDevices.
[ 214.485] (II) Loader magic: 0xb7008f18
[ 214.486] (II) Module ABI versions:
[ 214.486] X.Org ANSI C Emulation: 0.4
[ 214.487] X.Org Video Driver: 15.0
[ 214.487] X.Org XInput driver : 20.0
[ 214.489] X.Org Server Extension : 8.0
[ 214.495] Initializing built-in extension Generic Event Extension
[ 214.496] Initializing built-in extension SHAPE
[ 214.497] Initializing built-in extension MIT-SHM
[ 214.497] Initializing built-in extension XInputExtension
[ 214.498] Initializing built-in extension XTEST
[ 214.498] Initializing built-in extension BIG-REQUESTS
[ 214.499] Initializing built-in extension SYNC
[ 214.500] Initializing built-in extension XKEYBOARD
[ 214.500] Initializing built-in extension XC-MISC
[ 214.501] Initializing built-in extension SECURITY
[ 214.501] Initializing built-in extension XINERAMA
[ 214.503] Initializing built-in extension XFIXES
[ 214.503] Initializing built-in extension RENDER
[ 214.504] Initializing built-in extension RANDR
[ 214.505] Initializing built-in extension COMPOSITE
[ 214.505] Initializing built-in extension DAMAGE
[ 214.506] Initializing built-in extension MIT-SCREEN-SAVER
[ 214.506] Initializing built-in extension DOUBLE-BUFFER
[ 214.507] Initializing built-in extension RECORD
[ 214.507] Initializing built-in extension DPMS
[ 214.508] Initializing built-in extension Present
[ 214.508] Initializing built-in extension DRI3
[ 214.509] Initializing built-in extension X-Resource
[ 214.509] Initializing built-in extension XVideo
[ 214.510] Initializing built-in extension XVideo-MotionCompensation
[ 214.512] Initializing built-in extension SELinux
[ 214.513] Initializing built-in extension XFree86-VidModeExtension
[ 214.514] Initializing built-in extension XFree86-DGA
[ 214.514] Initializing built-in extension XFree86-DRI
[ 214.515] Initializing built-in extension DRI2
[ 214.516] (II) LoadModule: "glx"
[ 214.537] (II) Loading /usr/lib/xorg/modules/extensions/libglx.so
[ 214.612] (II) Module glx: vendor="X.Org Foundation"
[ 214.613] compiled for 1.15.1, module version = 1.0.0
[ 214.614] ABI class: X.Org Server Extension, version 8.0
[ 214.615] (==) AIGLX enabled
[ 214.616] Loading extension GLX
[ 214.619] (==) Matched modesetting as autoconfigured driver 0
[ 214.619] (==) Matched fbdev as autoconfigured driver 1
[ 214.620] (==) Assigned the driver to the xf86ConfigLayout
[ 214.621] (II) LoadModule: "modesetting"
[ 214.625] (II) Loading /usr/lib/xorg/modules/drivers/modesetting_drv.so
[ 214.628] (II) Module modesetting: vendor="X.Org Foundation"
[ 214.629] compiled for 1.15.0, module version = 0.8.1
[ 214.630] Module class: X.Org Video Driver
[ 214.630] ABI class: X.Org Video Driver, version 15.0
[ 214.631] (II) LoadModule: "fbdev"
[ 214.635] (II) Loading /usr/lib/xorg/modules/drivers/fbdev_drv.so
[ 214.638] (II) Module fbdev: vendor="X.Org Foundation"
[ 214.639] compiled for 1.15.0, module version = 0.4.4
[ 214.639] Module class: X.Org Video Driver
[ 214.640] ABI class: X.Org Video Driver, version 15.0
[ 214.642] (II) modesetting: Driver for Modesetting Kernel Drivers: kms
[ 214.644] (II) FBDEV: driver for framebuffer: fbdev
[ 214.647] (--) using VT number 7
[ 214.652] (WW) Falling back to old probe method for modesetting
[ 214.656] (EE) open /dev/dri/card0: No such file or directory
[ 214.657] (WW) Falling back to old probe method for fbdev
[ 214.658] (II) Loading sub module "fbdevhw"
[ 214.658] (II) LoadModule: "fbdevhw"
[ 214.663] (II) Loading /usr/lib/xorg/modules/libfbdevhw.so
[ 214.666] (II) Module fbdevhw: vendor="X.Org Foundation"
[ 214.669] compiled for 1.15.1, module version = 0.0.2
[ 214.669] ABI class: X.Org Video Driver, version 15.0
[ 214.671] (EE) open /dev/fb0: No such file or directory
[ 214.672] (EE) No devices detected.
[ 214.674] (==) Matched modesetting as autoconfigured driver 0
[ 214.674] (==) Matched fbdev as autoconfigured driver 1
[ 214.675] (==) Assigned the driver to the xf86ConfigLayout
[ 214.675] (II) LoadModule: "modesetting"
[ 214.679] (II) Loading /usr/lib/xorg/modules/drivers/modesetting_drv.so
[ 214.680] (II) Module modesetting: vendor="X.Org Foundation"
[ 214.681] compiled for 1.15.0, module version = 0.8.1
[ 214.681] Module class: X.Org Video Driver
[ 214.682] ABI class: X.Org Video Driver, version 15.0
[ 214.682] (II) UnloadModule: "modesetting"
[ 214.683] (II) Unloading modesetting
[ 214.685] (II) Failed to load module "modesetting" (already loaded, -1205831248)
[ 214.686] (II) LoadModule: "fbdev"
[ 214.689] (II) Loading /usr/lib/xorg/modules/drivers/fbdev_drv.so
[ 214.690] (II) Module fbdev: vendor="X.Org Foundation"
[ 214.691] compiled for 1.15.0, module version = 0.4.4
[ 214.691] Module class: X.Org Video Driver
[ 214.692] ABI class: X.Org Video Driver, version 15.0
[ 214.692] (II) UnloadModule: "fbdev"
[ 214.694] (II) Unloading fbdev
[ 214.695] (II) Failed to load module "fbdev" (already loaded, -1205831248)
[ 214.695] (II) modesetting: Driver for Modesetting Kernel Drivers: kms
[ 214.696] (II) FBDEV: driver for framebuffer: fbdev
[ 214.699] (++) using VT number 7
[ 214.699] (WW) xf86OpenConsole: setpgid failed: Operation not permitted
[ 214.700] (WW) xf86OpenConsole: setsid failed: Operation not permitted
[ 214.701] (WW) Falling back to old probe method for modesetting
[ 214.702] (EE) open /dev/dri/card0: No such file or directory
[ 214.702] (WW) Falling back to old probe method for fbdev
[ 214.703] (II) Loading sub module "fbdevhw"
[ 214.703] (II) LoadModule: "fbdevhw"
[ 214.708] (II) Loading /usr/lib/xorg/modules/libfbdevhw.so
[ 214.708] (II) Module fbdevhw: vendor="X.Org Foundation"
[ 214.709] compiled for 1.15.1, module version = 0.0.2
[ 214.710] ABI class: X.Org Video Driver, version 15.0
[ 214.710] (EE) open /dev/fb0: No such file or directory
[ 214.711] (EE) No devices detected.
[ 214.711] (EE)
Fatal server error:
[ 214.714] (EE) no screens found(EE)
[ 214.716] (EE)
Please consult the The X.Org Foundation support
at http://wiki.x.org
for help.
[ 214.717] (EE) Please also check the log file at "/var/log/Xorg.0.log" for additional information.
[ 214.718] (EE)
[ 214.723] (EE) Server terminated with error (1). Closing log file.
The complete steps it took me to create and boot an ARM-Ubuntu image are below (based on https://wiki.ubuntu.com/Kernel/Dev/QemuARMVexpress ):
# 1) setup the rootfs
sudo apt-get install qemu-user-static qemu-system-arm
mkdir vexpress
cd vexpress
mkdir qemu-img
# Create 8-GB image
dd if=/dev/zero of=./vexpress-8G.img bs=8M count=1024
sudo losetup -f ./vexpress-8G.img
sudo mkfs.ext4 /dev/loop0
sudo mount /dev/loop0 qemu-img
# Bootstrap Ubuntu Trusty armhf rootfs in the qemu-img directory
# For Ubuntu versions later than Trusty some commands fail
# For Ubuntu versions before Saucy there is no port to ARM
# Ubuntu Saucy is not supported anymore
sudo qemu-debootstrap --arch=armhf trusty qemu-img
sudo cp `which qemu-arm-static` qemu-img/usr/bin/
# setup serial console, apt repositories and network
sudo chroot qemu-img
sed 's/tty1/ttyAMA0/g' /etc/init/tty1.conf > /etc/init/ttyAMA0.conf
echo "deb http://ports.ubuntu.com trusty main restricted multiverse universe" > /etc/apt/sources.list
apt-get update
echo -e "\nauto eth0\niface eth0 inet dhcp" >> /etc/network/interfaces
# root password
passwd
# 2) pick and install a kernel
# Fix locale problems http://askubuntu.com/questions/162391/how-do-i-fix-my-locale-issue
locale
sudo locale-gen "be_BY.UTF-8"
sudo locale-gen "en_US"
sudo locale-gen "en_US.UTF-8"
sudo dpkg-reconfigure locales
apt-get install wget ca-certificates
wget https://launchpad.net/ubuntu/+archive/primary/+files/linux-image-3.13.0-24-generic-lpae_3.13.0-24.46_armhf.deb
dpkg -i linux-image-3.13.0-24-generic-lpae_3.13.0-24.46_armhf.deb
# So far I'm getting the following warnings:
# Warning: cannot read table of mounted file systems: No such file or directory
# warning: failed to read mtab
# !!! press CTRL+D to exit the chroot
^D
# 3) Boot it up
# copy kernel, initrd and dtb files
sudo cp qemu-img/boot/vmlinuz-3.13.0-24-generic-lpae .
sudo cp qemu-img/boot/initrd.img-3.13.0-24-generic-lpae .
sudo cp qemu-img/lib/firmware/3.13.0-24-generic-lpae/device-tree/vexpress-v2p-ca15-tc1.dtb .
# umount the rootfs img
sudo umount qemu-img
sudo chmod 777 vmlinuz-3.13.0-24-generic-lpae
sudo chmod 777 initrd.img-3.13.0-24-generic-lpae
sudo chmod 777 vexpress-v2p-ca15-tc1.dtb
sudo chmod 777 vexpress-8G.img
# http://unix.stackexchange.com/questions/167165/how-to-pass-ctrl-c-in-qemu
# Allow Ctrl+C and Ctrl+Z on guest, changing them on host to Ctrl+] and Ctrl+[
stty intr ^]
stty susp ^j
qemu-system-arm -smp 2 --drive format=raw,if=sd,file=vexpress-8G.img -kernel vmlinuz-3.13.0-24-generic-lpae -initrd initrd.img-3.13.0-24-generic-lpae -M vexpress-a15 -serial stdio -m 2048 -append 'root=/dev/mmcblk0 rw mem=2048M raid=noautodetect rootwait console=ttyAMA0,38400n8 devtmpfs.mount=0' -dtb ./vexpress-v2p-ca15-tc1.dtb
I don't know if it's an Ubuntu (software) or QEmu (emulated hardware) problem.
来源：https://stackoverflow.com/questions/39043803/black-screen-in-qemu-for-arm-ubuntu-how-to-get-gui