Basic power profiling method in the device

1. With Power board (hardware)
 - https://mostly-tech.com/2015/05/31/how-to-power-profile-your-app-using-hardware/
 - http://www.anandtech.com/print/6529/busting-the-x86-power-myth-indepth-clover-trail-power-analysis
2. Clock profiling (software)
 - Application processor is consist of CPU, GPU, BUS, ...
3. With tools (software)
3.1 ARM DS-5 stream line
 - https://developer.arm.com/products/software-development-tools/ds-5-development-studio/streamline
3.2 TOP command (process load)
 - http://www.tecmint.com/12-top-command-examples-in-linux/
 - https://www.lifewire.com/linux-top-command-2201163
3.3 Systrace
 - https://developer.android.com/studio/profile/systrace-commandline.html
 - https://developer.android.com/studio/profile/systrace.html

LTE CDRX and Power consumption

What is the CDRX
CDRX stands for Connected Discontinus Rx (reception).
 - http://www.simpletechpost.com/
 - http://www.sharetechnote.com/html/Handbook_LTE_DRX.html

About Power
Optimize UE Design for Greater Battery Run-Time
 - http://www.keysight.com/upload/cmc_upload/All/Optimize_UE_design_for_greater_battery_run-time_V3.pdf

In the 3G network
 - http://gsmaterminals.github.io/Developer-Guidelines-Public/
   refer to "3.3 Efficient Network Connection Usage"

Benchmark Android vs. iPhone

Powerful

https://daringfireball.net/linked/2016/09/14/geekbench-android-a10
http://bgr.com/2016/09/15/iphone-7-vs-android-benchmarks/

Android OS vs. Android System

Android OS is based on Linux Kernel. It is low level kernel.
Android System is based on Android Platform. It is high level System.


Android System Arcitecture

+- Application Framework
+- Binder IPC Proxies
+- Android System Services (Media Server, System Server)
+- HAL
+- Linux Kernel

Android System controlls hardware with HAL interface. And HAL interface conncted with Linux Kernel. That is Android OS is Linux Kernel (low level kernel), Android System is Android platform.

1. http://forum.xda-developers.com/showpost.php?p=10922010&postcount=3
2. http://android.stackexchange.com/questions/11985/what-is-the-difference-between-the-android-os-and-android-system
3. https://source.android.com/devices/

In gvim, how can I set or change font size and type?

If you use vim, copy .vimrc to .gvimrc
1. cp .vimrc .gvimrc
2. open .gvimrc
3. add
 set fgn=Monospace\ Regular\ 12

After executing gvim, you can find changed font type and size.

http://www.troubleshooters.com/linux/vifont.htm

How to capture TCP dump in iPhone?

1. Need a Mac PC.
2. Install Xcode in the Mac
 - check UDID
 - execute rvictl command
3. Run Xcode > Window > Devices
 iPhone > Identifier
4. Run Terminal
 $ rvictl -s

 # start capturing TCP dump
 $ sudo tcpdump -i rvi0 -w trace.pcap

 # stop capturing TCP dump
 $ rvictl -x

* Reference
https://developer.apple.com/library/mac/qa/qa1176/_index.html
http://useyourloaf.com/blog/2012/02/07/remote-packet-capture-for-ios-devices.html

Android sleep

1. Wake up
write on /sys/power/state
2. Sleep
write mem /sys/power/state

Why mem?
I think mem means that suspend to RAM (memory).

From the Linux Document
https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-power
and https://www.kernel.org/doc/Documentation/power/states.txt