gcc 4.7, g++ 4.7 install on 12.04 LTS

1. Update apt repositories

$ sudo add-apt-repository ppa:ubuntu-toolchain-r/test
$ sudo apt-get update

2. Check

$ sudo apt-cache search "g\+\+"

3. Install

$ sudo apt-get install gcc-4.7 g++-4.7

4. Set as a default gcc

$ sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.6 60 --slave /usr/bin/g++ g++ /usr/bin/g++-4.6
$ sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.7 40 --slave /usr/bin/g++ g++ /usr/bin/g++-4.7
$ sudo update-alternatives --config gcc
then Select gcc-4.7

5. Confirm

dokyun@redbomb-server:~$ g++ --version
g++ (Ubuntu/Linaro 4.7.3-2ubuntu1~12.04) 4.7.3
Copyright (C) 2012 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
dokyun@redbomb-server:~$

Cyanogenmod source code build env setup ( cm-11 )

You must setup android development enviroment before getting source code cm-11 .
Refer to
http://dokyunblog.blogspot.kr/2012/07/android-tool-chain-install.html

• Download cyanogenmod source code

$ mkdir ~/cm-11

$ cd ~/cm-11

$ repo init -u git://github.com/CyanogenMod/android.git -b cm-11.0

$ repo sync

It take over than 1 hour....keep patient
Refer to https://github.com/CyanogenMod/android/tree/cm-11.0

• Download device specific source code

Run build enviroment setup script.
dokyun@redbomb-server:~/cm-11$ source ./build/envsetup.sh

Then execute lunch command

LG G Pad install stock rom

1. Go into download mode.
 Power off , push volume up/down and power button simultaniouly for a while
when it shows "dwonload mode" box on the screen,

2. go lg mobile downloda center
http://www.lgmobile.co.kr/lgmobile/front/download/retrieveDownloadMain.dev

3. follow as below

























4. Then LG Mobile Support Tool pop-up

5. Install USB driver then connect G-Pad

6. Then select 부가기능 > 업그레이드 오류복구

In my case it takes about 11 minutes...

LG G Pad 8.3 v50020a Custom recovery install (TWRP)

There are a lot of methos to unlock bootloader and intall custom recovery for old version of LG G Pad. I tried to those methods...but noting works

Only the below,works under v50020a, before doing this, you must root device.

http://forum.xda-developers.com/showthread.php?t=2698267

In my case, adb reboot recovery command does not works after intalling TWRP.
but I can go into custom recovery mode by key combination.

After installing , you can see below messages when it boot as recovery mode but nothing happens

Refer to below, end of this video show how to go into recovery mode by key combination after TWRP install.

http://www.youtube.com/watch?v=_tOtfF6gKkg

Setup Android NDK under windows

1. Install cgywin.
 Because windows doesn't have gcc build env, we must install cgywin
 Dowload cgywin here
 http://www.cygwin.com/
 and choose install option only devel

In Korean case, add this http://ftp.daum.net/cygwin for download mirror site.

2. Install Android NDK

downlodd Android NDK here and unzip
http://developer.android.com/tools/sdk/ndk/index.html

For convenience, I unziped it on cygwin/home/administrator directory

3. Setup path

Open .bashrc or .bash_profile export NDK directory
( In my case it located on C:\cygwin\home\Administrator )
export ANDROID_NDK_ROOT=/home/Administrator/android-ndk-r9

Add NDK directory to path
PATH="$PATH:$ANDROID_NDK_ROOT"

Save and close

4. Check NDK sample build
 Move to NDK sample directory and build

$ cd android-ndk-r9/samples/hello-jni/jni
$ ndk-build

then you can see belows

Gdbserver      : [arm-linux-androideabi-4.6] libs/armeabi/gdbserver
Gdbsetup       : libs/armeabi/gdb.setup
Cygwin         : Generating dependency file converter script
Compile thumb  : hello-jni <= hello-jni.c
SharedLibrary  : libhello-jni.so
Install        : libhello-jni.so => libs/armeabi/libhello-jni.so

참 쉽죠~~

setup android app development enviroment

1. Install JDK

 Download JDK and install latest version
 http://www.oracle.com/technetwork/java/javase/downloads/index.html

2. Install ADT (Android Development toolkit)
 Download ADT and unzip , it does not need to install
 http://developer.android.com/sdk/index.html

3. Run SDK Manager under ADT installed directory and install SW pacakges what you need
 In my case, it located C:\adt-bundle-windows-x86-20131030\SDK Manager.exe and Android 4.3(API18) is installed

4. After installing package, run eclipse.
 In my case, it loacated C:\adt-bundle-windows-x86-20131030\eclipse\eclipse.exe

5. Set up virtual device for debugging
Select menu > windows > android SDK manager then tools > manageADVs on android SDK manager dialog and create virtual device. If your PC is not good enough, vitual device can not run. In this case, select lpw option of vitual device

6. Make sample project
 Select file > new > android application project.
 Now just setup project name and use default others (just click next)

7. Build project
 Right click Project name on Project ecplorer, then select debug as >  android application
 then application runs on ADV

8. Create APK  If you want to install on the phone, you must create APK file
 Right click Project name on Project ecplorer, then Android tools > export signed application package
 There is unsigned application package, if you create unsigned package , it can not be intalled so you shoud be better install signed package

For creating signed package, you need keystore. If you already have keystore, select "use existing keystore", if not, select "Create new keystore"

9. Phone test
 Copy Created APK file to youer phone and run

sobel filter by using 2D image interface opencl

I made a simple image sobel filter application using 2D interfacing example.
Firt add sobel filter kernel into imagecpy.cl file and create sobel filter kernel instead of image2d_copier.

__kernel void sobel_rgb(read_only image2d_t src, write_only image2d_t dst, sampler_t sampler)
{
  int x = (int)get_global_id(0); int y = (int)get_global_id(1);
 
  float4 p00 = read_imagef(src, sampler, (int2)(x - 1, y-1));
  float4 p10 = read_imagef(src, sampler, (int2)(x, y-1));
  float4 p20 = read_imagef(src, sampler, (int2)(x + 1, y-1));
  float4 p01 = read_imagef(src, sampler, (int2)(x - 1, y));
  float4 p21 = read_imagef(src, sampler, (int2)(x + 1, y));
  float4 p02 = read_imagef(src, sampler, (int2)(x - 1, y+1));
  float4 p12 = read_imagef(src, sampler, (int2)(x, y+1));
  float4 p22 = read_imagef(src, sampler, (int2)(x + 1, y + 1));
 
  float3 gx = -p00.xyz + p20.xyz + 2.0f * (p21.xyz - p01.xyz) - p02.xyz + p22.xyz;
  float3 gy = -p00.xyz - p20.xyz + 2.0f * (p12.xyz - p10.xyz) + p02.xyz + p22.xyz;
  float3 norm = gx * gx + gy * gy;
  float3 g = native_sqrt(norm.x+norm.y+norm.z);
  write_imagef(dst, (int2)(x, y), (float4)(g.x, g.y, g.z, 1.0f));
 
}

I got the result as below

참 쉽죠~~