tutorials

Posted on by Jean-Luc Aufranc (CNXSoft) - 2 Comments on 15 Linaro OnAir Sessions about Android, Linux, Debugging and Software QA

15 Linaro OnAir Sessions about Android, Linux, Debugging and Software QA

Linaro has planned 15 virtual conferences between Monday, August 13 and Saturday, August 18, 2012. Those online events will deal with the work done at Linaro, including software optimization, software QA, Android and Linux kernel development, Open Embedded on ARMv8 and more. Those conferences are public and anybody can join. All times indicated below are GMT+07:00 (Bangkok), so you can either mentally convert the time (recommended), or click on the links below to get the date and time in your timezone. Exploring The Performance Impact of PGO and LTO on ARM– Mon, August 13, 5:00 PM Abstract: Profile guided and linked time optimisation (PGO and LTO) are two of GCC’s cross program optimisations that should improve both the startup and runtime of typical programs.  We know that they basically work on ARM but don’t know the potential speed up or the work involved in proper support. This session will cover […]

Posted on by Jean-Luc Aufranc (CNXSoft) - 38 Comments on How To Root CX-01 Android mini PC

How To Root CX-01 Android mini PC

CX-01 is a cool low cost Android mini PC (as low as $40), but unlike many other Chinese Android device it is not rooted. Here are the instructions to root it: Download Unlock Root http://www.unlockroot.com/. NB: The download link does not appear to work right now, but the filename is unlockroot23.exe, so here are some alternative untested download links. Find Unlockroot\driver\android_winusb.inf in the directory where you install Unlockroot Open the file in a text editor, and add the following lines: For Win 7 (64-bit): [Google.NTamd64] 64-bit] ;TCC8920 %SingleAdbInterface% = USB_Install, USB\Vid_18D1&Pid_DEED&MI_01 %CompositeAdbInterface% = USB_Install, USB\Vid_18D1&Pid_DEED&Rev_0231&MI_01 For WinXP (32-bit): [Google.NTx86] ;TCC8920 %SingleAdbInterface% = USB_Install, USB\Vid_18D1&Pid_DEED&MI_01 %CompositeAdbInterface% = USB_Install, USB\Vid_18D1&Pid_DEED&Rev_0231&MI_01 Connect CX-01 to your PC via USB, it should then detect your new device. If it doesn’t simply press “fn” key on CX-01 TV Stick. Select the driver that you edited in Unlockroot\driver\android_winusb.inf Once the driver is installed, run unlockroot Press ROOT, then […]

Posted on by Jean-Luc Aufranc (CNXSoft) - 82 Comments on 84 MB Minimal Raspbian ARMHF Image for Raspberry Pi

84 MB Minimal Raspbian ARMHF Image for Raspberry Pi

Many embedded systems applications do not require a desktop environment or graphical interface on the screen (e.g. server), and you may want to only install the files you really need on the SD card either to reserve as much space as possible for data and/or your program or to reduce costs. After searching for a minimal image based on Raspbian ARMHF distribution for the Raspberry, I could only find Linux Systems minimal image based on the Alpha version of the Raspbian Wheezy. Their compressed image is 109 MB in size, has a custom kernel,  sshd and ntpd are enabled, but the wireless tools were deleted, and at the time the swap was located in another partition instead of a file inside the rootfs. The uncompress rootfs is about 414 MB (as reported by df -h when mounted as a loop device). I decided to prepare a minimal image myself based […]

Posted on by Jean-Luc Aufranc (CNXSoft) - No Comments on LinuxCon North America 2012 Schedule

LinuxCon North America 2012 Schedule

LinuxCon (North America) 2012 will take place on August 29 – 31, 2012 at Sheraton Hotel & Marina, in San Diego, California. The event will be co-located with the Linux Kernel Summit, the Linux Plumbers Conference, and CloudOpen 2012. LinuxCon consists of 3 days of keynotes, business and developers related sessions as well as tutorials. There will be over 80 sessions and keynotes during those 3 days. I’ll highlight a few sessions that I find particularly interesting and related to embedded Linux, software development and ARM. August 29 10:45 – 11:30 – Life After BerkeleyDB: OpenLDAP’s Memory-Mapped Database by Howard Chu, Symas Abstract: OpenLDAP’s new MDB library is a highly optimized B+tree implementation that is orders of magnitude faster and more efficient than everything else in the software world. Reads scale perfectly linearly across arbitrarily many CPUs with no bottlenecks, and data is returned with zero memcpy’s. Writes are on […]

Posted on by Jean-Luc Aufranc (CNXSoft) - No Comments on AnDevCon IV Classes and Workshops Schedule

AnDevCon IV Classes and Workshops Schedule

AnDevCon is a technical conference for software developers building Android apps, and the fourth Android developer conference will take place in San Francisco on December 4-7, 2012. The organizers have already listed the schedule, including details about the workshops and classes which will take place at the conference. The 4th of December is reserved for workshops, and the other 3 days can be spent on shorter classes. All workshops will provide sample code, as well as most classes, excluding the overview session and business related sessions. There will be three full day Android workshops: Android Development Boot Camp – Hands-on introduction to Android application development and the tools essential to the process. Beyond an introduction to the basics, this workshop also covers some of the common hurdles met with development, and how to overcome them. You will also have the opportunity to build an Android app of your own where […]

Posted on by Jean-Luc Aufranc (CNXSoft) - 25 Comments on How To Use Putty with an SSH Private Key Generated by OpenSSH

How To Use Putty with an SSH Private Key Generated by OpenSSH

I have access to a remote server where I am only allowed to login via SSH with a key, and I can’t add an extra key by myself, as described in “No Password SSH” post. The private key (RSA) has been generated with ssh-keygen in Linux, and I can login from Linux without issue. This morning, I wanted to do the same with Putty in Windows XP, so I just copied the private key to Windows and loaded it in Putty, but it failed:

After a few minutes of research, I found my answer on UbuntuForums, and the reason it fails is because Putty does not support openssh keys, but uses its own format. Here’s what I had to do: Convert OpenSSH private key to Putty private key with Putty Key Generator (puttygen) Start puttygen, and click on Conversions->Import key, then click Browse and select the private key generated with […]

Posted on by Jean-Luc Aufranc (CNXSoft) - 6 Comments on Installing Android SDK on Ubuntu 12.04

Installing Android SDK on Ubuntu 12.04

The official instructions to install Android SDK do not appear to be really up-to-date for Ubuntu 12.04, so I’ll post how I’ve installed the Android SDK and Eclipse on Ubuntu 12.04. First download and decompress Android SDK for Linux:

on 64-bit Ubuntu:

Sun Java is not part of Ubuntu packages anymore, so you’ll need to use openjdk instead

Now install the SDK

Android SDK Manager should show up. Use the default recommended packages and platforms, as well as any extra packages you may need, and click on Install x packages, accept all licenses and after installation is complete, the Android SDK is installed. Eclipse IDE is optional, but it’s the most widely used IDE to develop Android apps. You can install Eclipse as follows:

Once both Android packages and platforms, and eclipse are installed, start eclipse:

Then in the top menu, click on Help->Install […]

Posted on by Jean-Luc Aufranc (CNXSoft) - 81 Comments on Hardware Packs for AllWinner A10 Devices and Easier Method to Create a Bootable Ubuntu 12.04 SD Card

Hardware Packs for AllWinner A10 Devices and Easier Method to Create a Bootable Ubuntu 12.04 SD Card

Linaro has a tool called linaro-media-create to install Linaro Ubuntu to an SD card by passing the device, hardware pack file, the rootfs and the board as arguments. Hardware packs are files that contains hardware specific binaries and configs files (e.g. bootloader, kernel…). I’ve done something similar (albeit more basic) for AllWinner A10 devices so that you can easily install and run Ubuntu (and possibly other distributions) on an SD card. I’ve written 2 scripts for this: a10-hwpack-bld.sh – Script to generate evb.bin, build the latest u-boot and linux kernel, retrieve some config files and compress all this in an hardware pack file a1x-media-create.sh – Script to make a bootable SD card for AllWinner A10 devices. You can get the scripts with git:

I’ve only tested it with Mele A1000, but if you have other A10 devices such as MK802 mini PC or MINI X media player, it should […]

UP 7000 x86 SBC