Posted by Cliff Brake on 2009-11-23 | 
9 Comments to Read
This article provides an overview of the Linux kernel support for the suspend state in the TI OMAP3. Power management has always been one of the more difficult parts of a system to get right. The OMAP3 power management is quite extensive. There are many levels of very granular control over the entire system. Initially, [...]
Posted by Cliff Brake on 2009-11-19 | 3 Comments to Read
I just received an email notification from EMS (http://ems-wuensche.com/) that support for their CAN controllers is now in mainline Linux kernels. The EMS PCI products are supported in 2.6.31, and the CPC-USB product will be supported in 2.6.32. I’ve used various Linux CAN stacks in the past, but none were as well integrated as the [...]
Posted by Cliff Brake on 2009-11-05 | 2 Comments to Read
I do quite a few OpenEmbedded project builds during the course of a week. This process usually takes 3-5 minutes. That is just enough time to get distracted doing something else and forget about the build until an hour later when you realize — oops, I was supposed to send out a release email once [...]
Posted by Cliff Brake on 2009-10-13 | 2 Comments to Read
A common question is how do you do kernel development with OpenEmbedded? Typically, OpenEmbedded builds a kernel by checking the source out of a git repository, or by applying patch files to a released version of the kernel. See the many recipes for examples. This works very well for a Linux distribution build system, but [...]
Posted by Cliff Brake on 2009-09-08 | 6 Comments to Read
I recently wrote an article about best practices building Qt applications with OpenEmbedded, and it occured to me that I should write an equivalent article for Gtk+ applications. The same points apply — put your application source in a SCM system, and put the install logic in the application source (read the above article). The [...]
Posted by Cliff Brake on 2009-08-06 | 14 Comments to Read
This article describes how to cross compile a Qt application (named qt_tutorial) with OpenEmbedded, and several best practices you should consider. OpenEmbedded currently includes fairly good support for building Qt — both Qt Embedded and Qt X11. OE also includes a number of qt classes that make building Qt applications easy. One of the main [...]
Posted by Cliff Brake on 2009-07-30 | 2 Comments to Read
The Gumstix Overo Pinout Spreadsheet has been updated with the Palo board connector pinouts, and a few mistakes have been fixed.
Posted by Cliff Brake on 2009-07-14 | 4 Comments to Read
One task that is a often confusing to new OpenEmbedded users is how to capture changes to the source code for a package/recipe. First, lets review the progression in tools use to capture source code changes. In days of yore, developers often used gnu diff to capture modifications to a source tree. The typical practice [...]
Posted by Cliff Brake on 2009-06-20 | Read the First Comment
Occasionally I am asked how Embedded Linux compares with Windows CE. I have spent the past 5 years doing mostly embedded Linux development, and the previous 5 years doing mostly WinCE development with a few exceptions, so my thoughts are no doubt a little biased toward what I understand best. So take this with a [...]
Posted by Cliff Brake on 2009-05-26 | Be the First to Comment
I’m currently dealing with a programming problem where I need access to several 64MB, file-backed data structures concurrently on an Embedded Linux system that only has 64MB of RAM. The data structures are fairly sparse (mostly zero data), and I typically only need to access small portions of them at any particular time. There is [...]
Posted by Cliff Brake on 2009-05-13 | 2 Comments to Read
Very interesting news from MontaVista yesterday as they announced MontaVista Linux 6. It turns out they are using bitbake, which is the core of the OpenEmbedded build system. Along with the adoption of OpenEmbedded in many leading Embedded Linux efforts (Beagleboard, Gumstix, Bug Labs, etc), this is a resounding affirmation that the OpenEmbedded way of [...]
Posted by Cliff Brake on 2009-05-11 | Be the First to Comment
Although ssh and friends work really well for embedded systems, occasionally you want to set up a NFS root for development. One of the scenarios where nfsroot is useful is if you are making a lot of rootfs changes, and you don’t want to spend the time to reprogram the flash on the target system. [...]
Posted by Cliff Brake on 2009-04-24 | Be the First to Comment
The cm-x270 kernel support in OpenEmbedded has just been updated to version 2.6.29.
Posted by Cliff Brake on 2009-03-19 | Read the First Comment
The Wi2Wi W2CBW003 is a highly integrated module that provides both Wifi and Bluetooth radios for embedded designs. This module is ideal for embedded designs, as it provides a lot of functionality in a small package and includes standard interfaces like SPI, SDIO and serial that connect with most embedded CPUs. With the availability of [...]
Posted by Cliff Brake on 2009-03-04 | 4 Comments to Read
Marcin just published an interesting article about memory performance on various embedded systems using the hdparm -T as a simple benchmarq. This test gives a pretty good indicator of memory performance in the system. From the hdparm man page: Perform timings of cache reads for benchmark and comparison purposes. For meaningful results, this operation should [...]