Run GNOME on NanoPi M4 (RK3399)


/usr/bin/gnome-shell: symbol lookup error: /lib/ undefined symbol: gbm_bo_get_offset

Arch Linux

Mali GPU user space drivers

git clone
cd libmali-rk3399
# Build gbm wrapper
# Install to system
sudo cp conf/mali.conf /etc/
sudo cp -rd lib /usr/lib/mali
# Update cache
sudo ldconfig

Force use GLESv2

# /etc/clutter-1.0/settings.ini

Fix crash when maximizing window

GPU device access permission

# /etc/udev/rules.d/50-mali.rules 
KERNEL=="mali0", MODE="0666"
sudo chmod 0666 /dev/mali0

Start gdm.


[MIUI] Fix the problem communicate with Google servers

There was a problem communicating with Google servers.

How to fix
1. Download Open Google apps pico.
2. Extract PrebuiltGmsCorePi.apk.

lunzip Core/gmscore-arm64.tar.lz
tar xf Core/gmscore-arm64.tar
adb push gmscore-arm64/nodpi/priv-app/PrebuiltGmsCorePi/PrebuiltGmsCorePi.apk /sdcard

3. Replace PrebuiltGmsCorePi.apk.

dd if=/sdcard/PrebuiltGmsCorePi.apk of=/system/priv-app/PrebuiltGmsCorePi/PrebuiltGmsCorePi.apk bs=1M


Run QEMU with hardware virtualization on macOS

在macOS上通过虚拟机运行其它操作系统,又不想用商业软件,那么开源的QEMU是一个比较好的选择。QEMU的功能支持还是比较全面的,除了功能以外,使用虚拟机软件的用户最关心的就是性能了,一个好消息是macOS 10.10+版本已经引人了硬件虚拟化支持框架,也就是Hypervisor.framework,另一个好消息是QEMU也已支持该框架,也就是hvf accelerator。

1. macOS 10.10+
2. Macports

已经使用过的用户可能已经发现,QEMU使用hvf accelerator并开启多核是有问题的呀。的确,QEMU使用hvf accelerator以单核运行时没有问题,当使用-smp参数指定多核时,很大概率上虚拟机硬件初始化都完成不了就死机了。
不过,好消息是该问题也已经修复了,导致这个问题的原因是hvf accelerator代码设计没有考虑到虚拟机启动后所有hvf vcpu都在并行执行指令,其中包括硬件初始化的I/O模拟操作,多个CPU同时对同一硬件执行初始化显然是不行的。

Patch (已经合并上游社区)

Install QEMU

cd ~
git clone
sudo vim /opt/local/etc/macports/sources.conf
# Add local repositories
file:///Users/[YOUR USER NAME]/macports
rsync:// [default]
cd ~/macports
sudo port install qemu

Run Arch Linux
1. 下载Arch Linux安装ISO镜像。
2. 创建一个虚拟机磁盘镜像。
3. 开始安装新的系统。
4. 启动安装后的系统。

mkdir ~/system/images
qemu-img create -f qcow2 ~/system/images/arch.qcow2 40G
qemu-system-x86_64 -no-user-config -nodefaults -show-cursor \
    -M pc-q35-3.1,accel=hvf,usb=off,vmport=off \
    -cpu host -smp 4,sockets=1,cores=2,threads=2 -m 4096 \
    -realtime mlock=off -rtc base=utc,driftfix=slew \
    -drive file=~/system/images/arch.qcow2,if=none,format=qcow2,id=disk0 \
    -device virtio-blk-pci,bus=pcie.0,addr=0x1,drive=disk0 \
    -netdev user,id=net0,hostfwd=tcp::2200-:22 \
    -device virtio-net-pci,netdev=net0,bus=pcie.0,addr=0x2 \
    -device virtio-keyboard-pci,bus=pcie.0,addr=0x3 \
    -device virtio-tablet-pci,bus=pcie.0,addr=0x4 \
    -device virtio-vga,bus=pcie.0,addr=0x5 \
    -cdrom ~/archlinux-2019.01.01-x86_64.iso -boot d



Transparent proxy per application on Linux

This is a transparent proxy per app based on iptables + network classifier cgroup on Linux, and it’s more general than proxychains.

Build and install tproxy

git clone --recursive
cd hev-socks5-tproxy
sudo cp bin/hev-socks5-tproxy /usr/local/bin/
sudo cp conf/main.ini /usr/local/etc/hev-socks5-tproxy.conf

Install systemd serivce

# /etc/systemd/system/hev-socks5-tproxy.service
ExecStart=/usr/local/bin/hev-socks5-tproxy /usr/local/etc/hev-socks5-tproxy.conf

Install tproxy wrapper

# /usr/local/bin/tproxy
if [ ! -e ${NET_CLS_DIR} ]; then
	sudo sh -c "mkdir -p ${NET_CLS_DIR}; \
		chmod 0666 ${NET_CLS_DIR}/cgroup.procs; \
		echo ${NET_CLS_ID} > ${NET_CLS_DIR}/net_cls.classid; \
		iptables -t nat -D OUTPUT -p tcp \
			-m cgroup --cgroup ${NET_CLS_ID} \
			-j REDIRECT --to-ports ${TP_TCP_PORT}; \
		iptables -t nat -D OUTPUT -p udp --dport 53 \
			-m cgroup --cgroup ${NET_CLS_ID} \
			-j REDIRECT --to-ports ${TP_DNS_PORT}; \
		ip6tables -t nat -D OUTPUT -p tcp \
			-m cgroup --cgroup ${NET_CLS_ID} \
			-j REDIRECT --to-ports ${TP_TCP_PORT}; \
		ip6tables -t nat -D OUTPUT -p udp --dport 53 \
			-m cgroup --cgroup ${NET_CLS_ID} \
			-j REDIRECT --to-ports ${TP_DNS_PORT}; \
		iptables -t nat -I OUTPUT -p tcp \
			-m cgroup --cgroup ${NET_CLS_ID} \
			-j REDIRECT --to-ports ${TP_TCP_PORT}; \
		iptables -t nat -I OUTPUT -p udp --dport 53 \
			-m cgroup --cgroup ${NET_CLS_ID} \
			-j REDIRECT --to-ports ${TP_DNS_PORT}; \
		ip6tables -t nat -I OUTPUT -p tcp \
			-m cgroup --cgroup ${NET_CLS_ID} \
			-j REDIRECT --to-ports ${TP_TCP_PORT}; \
		ip6tables -t nat -I OUTPUT -p udp --dport 53 \
			-m cgroup --cgroup ${NET_CLS_ID} \
			-j REDIRECT --to-ports ${TP_DNS_PORT};" 2>&1 2> /dev/null
echo $$ > ${NET_CLS_DIR}/cgroup.procs
exec "$@"

How to use?

tproxy COMMAND
# For example
tproxy wget
tproxy makepkg


Dump VDSO via GDB

gdb /bin/bash
(gdb) b main
(gdb) r
(gdb) info proc map
Mapped address spaces:
          Start Addr           End Addr       Size     Offset objfile
      0x7ffff7fd1000     0x7ffff7fd3000     0x2000        0x0 [vdso]
(gdb) dump binary memory /tmp/ 0x7ffff7fd1000 0x7ffff7fd3000
(gdb) quit
file /tmp/
/tmp/ ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, BuildID[sha1]=1a3fac101214fe3ecfb3788d4f8af3018f1f2667, stripped


Disable IBus embed preedit text via dbus-send

dbus-send --bus="`ibus address`" --print-reply \
    --dest=org.freedesktop.IBus \
    /org/freedesktop/IBus \
    org.freedesktop.DBus.Properties.Set \
    string:org.freedesktop.IBus string:EmbedPreeditText variant:boolean:false


Linux simple source policy routing

Dual network connections


Routing policy
* Transmit via eth0 when source address is
* Transmit via eth1 when source address is


# eth0
ifconfig eth0 up
ip rule add from table 251
ip route add default via dev eth0 src table 251
# eth1
ifconfig eth1 up
ip rule add from table 252
ip route add default via dev eth1 src table 252


Configuring Bonding Manually via Sysfs

Configuring Bonding Manually via Sysfs

	Starting with version 3.0.0, Channel Bonding may be configured
via the sysfs interface.  This interface allows dynamic configuration
of all bonds in the system without unloading the module.  It also
allows for adding and removing bonds at runtime.  Ifenslave is no
longer required, though it is still supported.

	Use of the sysfs interface allows you to use multiple bonds
with different configurations without having to reload the module.
It also allows you to use multiple, differently configured bonds when
bonding is compiled into the kernel.

	You must have the sysfs filesystem mounted to configure
bonding this way.  The examples in this document assume that you
are using the standard mount point for sysfs, e.g. /sys.  If your
sysfs filesystem is mounted elsewhere, you will need to adjust the
example paths accordingly.

Creating and Destroying Bonds
To add a new bond foo:
# echo +foo > /sys/class/net/bonding_masters

To remove an existing bond bar:
# echo -bar > /sys/class/net/bonding_masters

To show all existing bonds:
# cat /sys/class/net/bonding_masters

NOTE: due to 4K size limitation of sysfs files, this list may be
truncated if you have more than a few hundred bonds.  This is unlikely
to occur under normal operating conditions.

Adding and Removing Slaves
	Interfaces may be enslaved to a bond using the file
/sys/class/net//bonding/slaves.  The semantics for this file
are the same as for the bonding_masters file.

To enslave interface eth0 to bond bond0:
# ifconfig bond0 up
# echo +eth0 > /sys/class/net/bond0/bonding/slaves

To free slave eth0 from bond bond0:
# echo -eth0 > /sys/class/net/bond0/bonding/slaves

	When an interface is enslaved to a bond, symlinks between the
two are created in the sysfs filesystem.  In this case, you would get
/sys/class/net/bond0/slave_eth0 pointing to /sys/class/net/eth0, and
/sys/class/net/eth0/master pointing to /sys/class/net/bond0.

	This means that you can tell quickly whether or not an
interface is enslaved by looking for the master symlink.  Thus:
# echo -eth0 > /sys/class/net/eth0/master/bonding/slaves
will free eth0 from whatever bond it is enslaved to, regardless of
the name of the bond interface.

Changing a Bond's Configuration
	Each bond may be configured individually by manipulating the
files located in /sys/class/net//bonding

	The names of these files correspond directly with the command-
line parameters described elsewhere in this file, and, with the
exception of arp_ip_target, they accept the same values.  To see the
current setting, simply cat the appropriate file.

	A few examples will be given here; for specific usage
guidelines for each parameter, see the appropriate section in this

To configure bond0 for balance-alb mode:
# ifconfig bond0 down
# echo 6 > /sys/class/net/bond0/bonding/mode
 - or -
# echo balance-alb > /sys/class/net/bond0/bonding/mode
	NOTE: The bond interface must be down before the mode can be

To enable MII monitoring on bond0 with a 1 second interval:
# echo 1000 > /sys/class/net/bond0/bonding/miimon
	NOTE: If ARP monitoring is enabled, it will disabled when MII
monitoring is enabled, and vice-versa.

To add ARP targets:
# echo + > /sys/class/net/bond0/bonding/arp_ip_target
# echo + > /sys/class/net/bond0/bonding/arp_ip_target
	NOTE:  up to 16 target addresses may be specified.

To remove an ARP target:
# echo - > /sys/class/net/bond0/bonding/arp_ip_target

To configure the interval between learning packet transmits:
# echo 12 > /sys/class/net/bond0/bonding/lp_interval
	NOTE: the lp_inteval is the number of seconds between instances where
the bonding driver sends learning packets to each slaves peer switch.  The
default interval is 1 second.

Example Configuration
	We begin with the same example that is shown in section 3.3,
executed with sysfs, and without using ifenslave.

	To make a simple bond of two e100 devices (presumed to be eth0
and eth1), and have it persist across reboots, edit the appropriate
file (/etc/init.d/boot.local or /etc/rc.d/rc.local), and add the

modprobe bonding
modprobe e100
echo balance-alb > /sys/class/net/bond0/bonding/mode
ifconfig bond0 netmask up
echo 100 > /sys/class/net/bond0/bonding/miimon
echo +eth0 > /sys/class/net/bond0/bonding/slaves
echo +eth1 > /sys/class/net/bond0/bonding/slaves

	To add a second bond, with two e1000 interfaces in
active-backup mode, using ARP monitoring, add the following lines to
your init script:

modprobe e1000
echo +bond1 > /sys/class/net/bonding_masters
echo active-backup > /sys/class/net/bond1/bonding/mode
ifconfig bond1 netmask up
echo + /sys/class/net/bond1/bonding/arp_ip_target
echo 2000 > /sys/class/net/bond1/bonding/arp_interval
echo +eth2 > /sys/class/net/bond1/bonding/slaves
echo +eth3 > /sys/class/net/bond1/bonding/slaves

See also: