How to use watchdog
Watchdog can be started by command echo 1 > /dev/watchdog. At this time if kernel do not get this command every 60 seconds, it will reboot PCBA. You can disable watchdog with command echo V > /dev/watchdog
How to recursively find something in AOSP
grep -iR 'getDisplayInfo: displayId' * grep -iR 'if (DEBUG)' * only in .h and .java files grep -r --include=*.h --include=*.java '1280' ./
How to rotate screen
Make /system writable ( mount -o remount,rw /system ) add in build.prop file ro.sf.hwrotation=180 or you can do it when you modify AOSP source: Add this line echo "ro.sf.hwrotation=180" to /home/urve/Desktop/EM3288Std/build/tools/buildinfo.sh
How to compile android image and kernel for RK3288 URVEBoard
You need some tools: 16GB RAM, 64 bit Ubuntu 12.04, 60GB dysku (najlepiej SSD) In Ubuntu console: sudo apt-get install git gnupg flex bison gperf build-essential \ zip curl libc6-dev libncurses5-dev:i386 x11proto-core-dev \ libx11-dev:i386 libreadline6-dev:i386 libgl1-mesa-glx:i386 \ g++-multilib mingw32 tofrodos gcc-multilib ia32-libs \ python-markdown libxml2-utils xsltproc zlib1g-dev:i386 sudo apt-get install ccache sudo apt-get install openjdk-7-jdk [...]
How to underclock/overclock RK3288 CPU
In kernel/arch/arm/boot/dts/rk3288-tb_8846.dts file there are lines that need to be changed &clk_core_dvfs_table { operating-points = < /* KHz uV */ 126000 900000 216000 900000 312000 900000 408000 900000 600000 900000 696000 950000 816000 1000000 1008000 1050000 //1200000 1100000 //1416000 1200000 //1512000 1300000 //1608000 1350000 //1704000 1350000 //1800000 1400000 >; support-pvtm = <1>; pvtm-operating-points = < /* [...]
How to change CPU frequency to maximum
echo userspace > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor echo 1608000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed 1608000 or set scaling_governor to ondemand echo ondemand > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
How to change most of default settings in AOSP
There are two files for it /frameworks/base/packages/SettingsProvider/res/values/defaults.xml /frameworks/base/core/res/res/values/config.xml
How to switch off device and switch on with Wake On LAN
To switch off echo mem >/sys/power/state To switch off with Wake On LAN use any WoL software
How to change wallpaper in my AOSP
Change file in AOSP source "/frameworks/base/core/res/res/drawable-nodpi/default_wallpaper.jpg" and build your image
How to use external LEDs
Type in console: echo 252 > /sys/class/backlight/rk32_bl/brightness # to light up green leds echo 252 > /sys/class/backlight/rk_bl/brightness # to light up red leds echo 0 > /sys/class/backlight/rk32_bl/brightness # to disable echo 0 > /sys/class/backlight/rk_bl/brightness