- Category: Embedded Systems
Virtualization for embedded systems
"Summary: Today's technical news is filled with stories of server and desktop virtualization, but there's another virtualization technology that's growing rapidly: embedded virtualization. The embedded domain has several useful applications for virtualization, including mobile handsets, security kernels, and concurrent embedded operating systems. This article explores the area of embedded virtualization and explains why it's coming to an embedded system near you."
- Category: Linux
Kernel logging: APIs and implementation
"Summary: In kernel development, we use printk for logging without much thought. But have you considered the process and underlying implementation of kernel logging? Explore the entire process of kernel logging, from printk to insertion into the user space log file."
- Category: Embedded Systems
Avoiding memory leaks in POSIX thread programming
"Summary: POSIX thread (pthread) programming defines a standard set of C programming language types, functions, and constants—and pthreads provide a powerful tool for thread management. To use pthreads to the fullest, you'll want to avoid the common mistakes. One common mistake is forgetting to join joinable threads, which can create memory leaks and cause extra work. In this tips-oriented article, learn the basics of POSIX threads, see how to identify and detect thread memory leaks, and get solid advice for avoiding them."
- Category: Samsung
ARM`s James Bruce on Exynos, big.LITTLE and SoC Design, Part I
"How has ARM come to be the industry standard for building mobile application processor (AP) structures?
In two fundamental ways: Through improving power efficiency (i.e. doing more with less) and through the ARM business model. In the past, a lot of people designed processors for use by their own companies, which had major challenges. It’s very expensive to actually design and build out your own processor, and you also have to worry about compatibility across the industry.
Now that we’ve developed a common, industry-standard CPU, system-on-chip (SoC) companies can build off of that blueprint much more easily. SoC companies like Samsung can now focus on designing their Exynos chips, rather than spending a lot of time and resources trying to design and build their own CPUs. ARM was one of the companies at the forefront of this changeover in business models, which is part of the reason why it is now regarded as the industry standard for mobile processors. "
- Category: USB
How to avoid a USB meltdown in harsh environments
" The USB specification
Indiana Jones and the Last Crusade is set in 1938. Had it been real life, Jones could never have his zeppelin adventure. (Commercial airship service had come to its abrupt end the year before.) But he might easily have lived long enough to see the introduction of electronic data communications and factory automation. He might even have lived long enough to see the introduction of USB.
Developed to be a universal serial bus, hence the name, USB was intended to simplify and standardize the connection of computer peripherals and to eliminate much of the need for specialized expansion cards, which were installed by opening the computer case and physically adding new parts to the machine. And it has proven to be a great improvement upon earlier data communications standards. USB not only simplifies installation, it allows you to connect up to 127 devices to a single port. Devices are also hot swappable, and it will supply 5 VDC power downstream. We’ve come a long way since the days of airships and singing telegrams. But the laws of physics have remained the same, and USB can’t get around them.
- Category: Cortex-A9
AML8726-MX
AML8726-MX is AMLogic dual core Cortex-A9 code named MESON6.
Linux GPL code release 2012-08-03 - kernel-common-2012-08-03-git-a63244fb9c.tar.gz - blog post web page link
fards Github project link
AMLogic OpenLinix - web page link
- Category: Uncategorised
Open source hardware
Thinking about releasing that open source board? Check these posts for some interesting thoughts on open source software vs hardware.
"Open source — be it software or hardware — is underpinned by liberal licensing which actively promotes reuse and building upon the work of others. But is it possible for copying within the terms of an open source licence to cross a line and to be considered bad practice, and are there times when open source simply isn't?"
Open Source (hardware) rules - web page link
"I truly believe open source hardware is here to stay. It has established itself as a great community, a great effort, and for many, a great business. I spend most of my days working on open source hardware in some way, and I wanted to talk about some of the {unspoken} rules we all, well, many, seem to follow. Why? Because the core group of people who’ve been doing what we’ve collectively called “open source hardware” know each other — we’re friends, we overlap and compete in some ways, but we all work towards a common goal: sharing our work to make the world a better place and to stand on each other’s shoulders and not each other’s toes : ) I’m sure there will be some folks who agree strongly with what I’ve outlined as “unspoken rules,” others, I hope will completely disagree with many points too. That’s great, it’s time we start this conversation."
The {Unspoken} Rules of Open Source Hardware - web page link
And finally some clone wars or "Cloning ain’t cool".
"Matt Strong invented a 3-D printer called TangiBot. More precisely, he built an exact replica of the MakerBot Replicator and is attempting to raise $500,000 on Kickstarter to fund its production.
In most cases, he would be met with a swift cease-and-desist letter, but the MakerBot Replicator is open source, meaning anyone can copy it and sell it. While legal, the TangiBot has raised the ethical hackles of many in the maker community.
Strong is unapologetic about the TangiBot’s lack of originality, saying, “I want to bring a low-cost machine to market that people can trust. The Replicator is the best and completely open source. I discussed the licenses with lawyers, and it’s totally legit.”"
Cloning the MakerBot Is Legal, But Does That Make It Right? - web page link
- Category: USB
WinUSB communication with STM32
Series of blog posts explaining step by step how to use WinUSB to communicate with embedded board based on STM32.
STM32 firmware source code and WinUSB demo application posted on Google Code.
"I wanted to test the use of WinUSB with STM32F103 for some time now. When I finally got time I created a demo project. It shows basic request - response communication.
WinUSB kernel mode driver enables raw communication through USB pipes. In other words you can communicate with your USB device directly from application on the PC. So there is only code for application and code for firmware. Presuming you are not making standard USB class device like Mass Storage or HID. You might not even need custom PC side software in this case.
Furthermore the libraries to communicate are written for both ends to some extent. There SetupAPI and WinUSB on Windows side while ST has libraries for everything."
Part 1: Intro - web page link
Part 2: Firmware - web page link
Part 3: Driver - web page link
Part 4: Software - web page link
Project Page - web page link
And a Darren Kattan comment from the blog:
"This whole process can be short-cutted by modifying your firmware to respond properly to Windows Extended IDs. Windows will them autobind the WinUSB driver."
STM32 WinUSB driver Autobinding. Get it here - web page link
- Category: Uncategorised
ARM Extends Toward a Future of Low-Power System Design
"Every system designer understands power-versus-performance trade-offs: the more computing performance your application requires, the more power your design will consume. But new classes of applications are challenging this rule. Smart-phone designers want to combine PC-level peak application speed with long battery life. Embedded-system architects dream of intelligent sensors that can perform demanding data analyses and connect securely to the Internet, but can operate indefinitely on scavenged power. By traditional thinking, these are clear impossibilities. But presentations by ARM engineers at the Design Automation Conference (DAC) in June showed the CPU intellectual-property (IP) leader moving in a direction that might make these impossibilities feasible."
"Running Very Slowly
Most systems have tasks that don’t need speed, they just need to get done. Often, they must remain active for one reason or another, so the system can’t simply switch on, rush through them, and then shut itself off again. There are energy-saving approaches specifically for minimizing leakage power in these tasks."
