To grant all permission to android app

To grant all permissions to app, use -g as argument while installing with adb

 adb install -g myapp.apk 

Cross Compiling Linux kernel for ARM

Get latest stable kernel source code

 git clone https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 

To get kernel-next branch clone

 git clone https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 

Get toolchain, e.g you can download linaro toolchain from Linaro toolchain for arm

set your path variable /path/to/linaro/binary/linaro/aarch64-unknown-linux-gnu_4.9-2014.05-01/bin

 export PATH=$PATH:/path/to/linaro/binary/linaro/aarch64-unknown-linux-gnu_4.9-2014.05-01/bin 

Setup defconfig file

 make ARCH=arm64 CROSS_COMPILE=aarch64-unknown-linux-gnu- O=output defconfig 

Make kernel image

 make ARCH=arm64 CROSS_COMPILE=aarch64-unknown-linux-gnu- O=output -j8 

To modify kernel configuration use

 make ARCH=arm64 CROSS_COMPILE=aarch64-unknown-linux-gnu- O=output menuconfig 

To save your modified defconfig file

 make ARCH=arm64 CROSS_COMPILE=aarch64-unknown-linux-gnu- O=output savedefconfig 

This will create defconfig file in output directory. Copy this file to your arch/arm64/configs directory

Adb over wifi, no USB cable required

Assumption is you are connected to device using UART for smoething similar so that you can run few commands on device

Find out the IP address of the Android device: Settings -> About tablet -> Status -> IP address. Remember the IP address, of the form #.#.#.#.

Steps on device
su
stop adbd
setprop service.adb.tcp.port 5555
start adbd

Steps on host
adb kill-server
sudo adb start-server
adb -a connect 192.168.1.64:5555

Dump audio to wav format using mplayer

mplayer input.mp4 -vc null -vo null -ao pcm:fast:waveheader:file=audio.wav

Play raw audio using mplayer

To play raw pcm file using mplayer use below command, which plays a pcm file "audio.pcm" whose sample rate is 192000 KHz, 32 bit, stereo

mplayer -rawaudio rate=192000:channels=2:samplesize=4 -format s32le -demuxer rawaudio audio.pcm

How to use bash function defined in .bashrc file into bash script

First define function in .bashrc and then export it

d2h(){
  echo "obase=16; $@"|bc
}
export -f d2h

Above function converts decimal to hex and then export it, so that it can be used from other bash scripts

Rescue and Recovery software

Trinity rescue kit is good software for recovery. It can reset password also. This can be run directly from usb drive using http://www.pendrivelinux.com/universal-usb-installer-easy-as-1-2-3/
http://trinityhome.org/