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October 8, 2011July 17, 2012 by Jean-Luc Aufranc (CNXSoft) - No Comments

Finding a Missing Package in Ubuntu with Aptitude

When you configure a program before building, it will usually check for dependencies and if one is missing it will return an error such as: checking for OPENSSL… configure: error: Package requirements (openssl) were not met: No package ‘openssl’ found Consider adjusting the PKG_CONFIG_PATH environment variable if you installed software in a non-standard prefix. It could be a PATH issue, but usually that simply means the development version of the library is not installed. Sometimes the name is easy to guess and can be installed with apt-get: sudo apt-get install packagename-devel But sometimes it’s more difficult to guess and Google is not always very helpful. In that case you can use aptitude to search for the package. For example for nss3: sudo aptitude search nss3 i libnss3 – Network Security Service libraries i libnss3-1d – Network Security Service libraries p libnss3-dbg – Development files for the Network Security p libnss3-dev […]

October 7, 2011July 17, 2012 by Jean-Luc Aufranc (CNXSoft) - No Comments

Embedded Linux Conference Europe 2011

Embedded Linux Conference Europe (ELC-E 2011) will take place on October 26 – 28, 2011 at Clarion Congress Hotel in Prague, Czech Republic. The event will be co-located with LinuxCon Europe 2011 and GStreamer Conference. The day before the official opening of the conference, two tutorials will be offered on Tuesday 25th of October:b Outside the Box: An Introduction to Embedded Linux and Hardware Interfacing Using the Snowball Board – 9:00 – 17:00 – Trainer: Chris Simmonds – Cost: 350 USD. Embedded Android Workshop – 9:00 – 17:00 – Trainer: Karim Yaghmour- Cost: 300 USD. ELCE consists of 3 days of presentations, tutorials and sessions. There will be over 50 sessions during those 3 days. I’ll highlight a few sessions that I find particularly interesting. October 26 10:45 – 11:45 – Linaro’s Android Platform by Zach Pfeffer, Linaro Android Platform team leader. Linaro uses components from the Android Open Source […]

October 6, 2011October 6, 2011 by Jean-Luc Aufranc (CNXSoft) - 2 Comments

Dropbear: Lightweight SSH Server / Client

You may need to remotely access your embedded device, or your embedded systems is simply headless. You could use telnet, but this is insecure. A secure way to access a device remotly is to use SSH protocol. OpenSSH is one implementation but this is relatively too large and may use uncesary space on a device with limited storage. That’s where Dropbear comes into play. Dropbear is a lightweight implementation of an SSH client and server and is ideal for embedded systems. Dropbear ARM executable is only 200 KB. Here’s how it’s described on its website: Dropbear is a relatively small SSH 2 server and client. It runs on a variety of POSIX-based platforms. Dropbear is open source software, distributed under a MIT-style license. Dropbear is particularly useful for “embedded”-type Linux (or other Unix) systems, such as wireless routers. The main features of dropbear: A small memory footprint suitable for memory-constrained […]

October 2, 2011June 28, 2021 by Jean-Luc Aufranc (CNXSoft) - 3 Comments

How to Transfer files between the Host and Qemu via SSH and NFS

Last week, I wrote a blog post explaining how to copy files to a qemu image by mounting the qemu image in the host. This is only useful if emulated platform does not support networking. If networking is enabled, using SSH (Secure Shell) or NFS (Network File System) is more convenient. Using SSH with Qemu To initiate the SSH connection from qemu, there is actually nothing extra to do as long as you have sshd installed and running on the host. If it is not installed simply run sudo apt-get install openssh-shell on the host. This will install and automatically sshd. To initiate the SSH connection from the host, you’ll have to redirect the ssh port to an unknown port and start qemu as follow (for overo):

sudo qemu-system-arm -M overo -m 256 -drive file=./overo_sd_alip.img,if=sd,cache=writeback -clock unix -serial stdio -device usb-kbd -device usb-mouse -redir tcp:2222::22

1	sudo qemu-system-arm -M overo -m 256 -drive file=./overo_sd_alip.img,if=sd,cache=writeback -clock unix -serial stdio -device usb-kbd -device usb-mouse -redir tcp:2222::22

Please refer to Beagleboard Emulator in Ubuntu with Qemu for the detailed instructions on how to setup qemu to emulate beagleboard or […]

September 23, 2011September 23, 2011 by Jean-Luc Aufranc (CNXSoft) - No Comments

UEFI Secure Boot – Windows 8 vs Linux

Last week, Microsoft showcased Windows 8 PCs with super fast boot thanks to the Unified Extensible Firmware Interface (UEFI). The latest UEFI standard, released on April 8, includes a secure boot protocol which will be required for Windows 8 clients. Secure UEFI is intended to thwart rootkit infections by requiring keys before allowing executables or drivers to be loaded onto the device. Problem is, such keys can also be used to keep the PC’s owner from wiping out the current OS and installing another option such as Linux. It all started with slide 11 in one Powerpoint presentation entitled “Delivering a secure and fast boot experience with UEFI” presented by Arie van der Hoeven, Principal Lead Program Manager Microsoft Corporation during Build conference: Secure boot Current issues with boot Growing class of malware targets the boot path Often the only fix is to reinstall the operating system UEFI and secure […]

September 22, 2011September 22, 2011 by Jean-Luc Aufranc (CNXSoft) - No Comments

Open a File Directly at the Requested Line with Vi

When you compile a program and an error occur, the compiler will report the file name and line number with the error. Usually, I use vi to access the file, then type “:line_num”, for example if I want to jump to line 123, I would type :123 after opening the file. But there is a way to do that directly with vi by using +line_num. For example: vi +123 code.c To go to the last line, I would normally use the capital letter G when vi is started, but this can be done while opening the file as follows: vi +$ code.c One last tip: To go back at the top of the file in vi, simply use :0 or the capital letter H. Jean-Luc Aufranc (CNXSoft)Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily […]

September 22, 2011September 22, 2011 by Jean-Luc Aufranc (CNXSoft) - 2 Comments

99 USD OMAP3 Based Overo Computer On Module by Gumstix

Gumstix has manufactured its Overo COMS based on OMAP3503 and OMAP3530 since 2008. They have now announced a new low cost version named Overa Sand that sells for 115 USD per unit or less than 99 USD per unit for orders of 1,000 units or more. Overo Sand COM is Gumstix’s most basic computer-on-module with 256MB RAM and no on-board NAND. Here are the board specifications and features: Processor: Texas Instruments OMAP 3503 Applications Processor: – ARM Cortex-A8 CPU @ 600 Mhz Memory: 256MB RAM NO On-Board NAND Included Features: microSD card slot TPS65950 Power Management Expandability: via one 140-pin expansion board of Gumstix Overo series or custom, 140-pin expansion board via 27-pin camera board Connections: – (2) 70-pin connectors with 140 signals for: – I2C, PWM lines (6), A/D (6), 1-wire – UART, SPI, Extra MMC lines – Headset, Microphone – Backup battery – High Speed USB Host and […]

September 22, 2011 by Jean-Luc Aufranc (CNXSoft) - 3 Comments

How-to Convert a Command Line Result into an Image in Linux

Here’s a technique to convert a command line result into an image in Linux using ImageMagick. You could also do a screenshot (with PrtSrc key) and use Gimp to trim the image, but this method is faster and does not require a graphical interface. The simplest command to convert the result of ifconfig into an image: ifconfig | convert label:@- cmd.png This will give an image with a white background and black text, but If you want to have a black background with white text you can use the following: ifconfig | convert -background black -fill white \ label:@- cmd.png If you want to change the font and the font size: ifconfig | convert -background black -fill white \ -font Helvetica -pointsize 14 \ label:@- cmd.png You can retrieve the list of fonts with this command: convert -list font | grep Font: Finally, use this command to add an extra […]