kernel

Posted on by Jean-Luc Aufranc (CNXSoft) - 1 Comment on Embedded Linux Boot Time Optimizations – ELCE 2012

Embedded Linux Boot Time Optimizations – ELCE 2012

Alexandre Belloni, embedded Linux engineer and trainer at Adeneo Embedded, gives a presentation about different techniques to optimize boot time for Embedded Linux at ELCE 2012. He also explains how they’ve measured the boot time. Abstract: A common problem faced when embedding Linux is the long boot time before the system is functional. There are many ways to improve boot up time. For a particular project, we had to answer a CAN message from Linux userspace in less than 420 ms from going out of CPU reset. We will describe our methodology and the techniques we finally chose to implement in that particular use case. We will also detail how we measured the boot time efficiently. A live demo will show the results of our work. More specifically, Alexandre discusses two projects at Adeneo where boot time was critical: An automotive platform based on Freescale i.mx53 needs to reply to […]

Posted on by Jean-Luc Aufranc (CNXSoft) - No Comments on Inside Android’s User Interface – ELCE 2012

Inside Android’s User Interface – ELCE 2012

Karim Yaghmour, Opersys inc, talks about the internals of the Android user interface at Embedded Linux Conference Europe on November 5, 2012. Abstract: Android is a very complex stack comprising several dozens of novel components and moving parts. Still, it’s intrinsically a user-centric system and, therefore, its parts which deal with user interface are of special interest for anyone aiming to put Android in a device. This talk will examine the internals of Android’s user-facing components. Specifically, we will cover the inner-workings and interactions of the Window Manager, Surface Flinger, Input Method Manager, and the rest of the system. We will also cover key display and input components such as the Status Bar, Soft Keyboard and Notifications. This talk will be especially useful to developers intending to use Android in user-facing embedded systems, those needing to implement support for their graphics hardware and anyone interested in the internals of Android’s […]

Posted on by Jean-Luc Aufranc (CNXSoft) - No Comments on Near Field Communication with Linux – ELCE 2012

Near Field Communication with Linux – ELCE 2012

Samuel Otiz, software engineer at the Intel Open Source Technology Center, talks about NFC support for Linux at the Embedded Linux Conference Europe in , on November 5, 2012. Abstract: Linux recently gained support for NFC (Neard Field Communication), and this presentation will describe the status of the current NFC stack in terms of actual features, hardware support and also distribution availability.After showing how this stack is architectured, we will also explain what our long and short term plans are. NFC hardware is typically found on mobile devices, many of them running Linux or Android. Up until recently, only Android provided a real and viable software support for those chipsets. During this presentation I will show how the Linux NFC stack is now getting on par with the Android stack features and API wise and how its design allows for an already broader range of supported chipsets. The presentation is divided into  […]

Posted on by Jean-Luc Aufranc (CNXSoft) - 4 Comments on Olimex A13-OLinuXino-MICRO Development Board Unboxing And Review

Olimex A13-OLinuXino-MICRO Development Board Unboxing And Review

Every Friday, Olimex organizes an online competition where they give away one of their board. They’ll ask a (usually simple) technical question on their twitter account at 22h00 (GMT+7), and all you have to do is to reply to their tweet with the correct answer within one hour. The winner is then selected randomly with random.org. There are usually 50 to 100 respondents so the odds are pretty good. I played a few times, and finally, I was lucky enough to win an A13-OLinuXino-MICRO development board at the beginning of December. I received it yesterday, after UPS took a whooping 15 days to deliver the board (Way to go UPS!). The board can be purchased on Olimex for 35 Euros plus shipping and taxes, or even lower if you order larger quantities. A13-OLinuXino-MICRO is a stripped down version of A13-OLinuXino-WIFI with the following specs: SoC – AllWinner A13 Cortex A8 […]

Posted on by Jean-Luc Aufranc (CNXSoft) - 5 Comments on Linaro 12.12 Release with Linux Kernel 3.7 and Android 4.2.1

Linaro 12.12 Release with Linux Kernel 3.7 and Android 4.2.1

Linaro release 12.12 has just been announced, and includes Linux Kernel 3.7 and Android 4.2.1. The tracking version (stable release) uses Kernel 3.4.22. This release upgrades Android to version 4.2.1, Ubuntu images are now based on Ubuntu 12.10 (Quantal Quetzal) and Linaro U-Boot 2012.12 has been released with support for Origen 4 Quad and Arndale boards. Further improvements have been done for OpenEmbedded ARMv8, where they replaced the php Apache module by php-fpm among other things. On the kernel side, USB drivers have been refactored, and a kernel size analysis have been performed on several platforms. The power management team has mainly worked on big.LITTLE IKS and MP implementations, and it’s the first time LEG (Linaro Enterprise Group) is included in the release, and they worked on UEFI for ARM, GRUB for U-Boot, and provided a Ubuntu server image for Arndale board which can boot via UEFI or UBoot. Here […]

Posted on by Jean-Luc Aufranc (CNXSoft) - 1 Comment on Linux 3.7 Release

Linux 3.7 Release

Linus Torvalds has announced the release of Linux Kernel 3.7: Whee. After an extra rc release, 3.7 is now out. After a few more trials at fixing things, in the end we ended up reverting the kswapd changes that caused problems. And with the extra rc, I had decided to risk doing the buffer.c cleanups that would otherwise have just been marked for stable during the next merge window, and had enough time to fix a few problems that people found there too. There’s also a fix for a SCSI driver bug that was exposed by the last-minute workqueue fixes in rc8. Other than that, there’s a few networking fixes, and some trivial fixes for sparc and MIPS. Anyway, it’s been a somewhat drawn out release despite the 3.7 merge window having otherwise appeared pretty straightforward, and none of the rc’s were all that big either. But we’re done, and […]

Posted on by Jean-Luc Aufranc (CNXSoft) - 44 Comments on Cubieboard Unboxing and Quick Start Guide

Cubieboard Unboxing and Quick Start Guide

I’ve received another cool board this week with the Cubieboard development board. As a quick reminder, the Cubieboard is the only proper low cost AllWinner A10 development board available, and comes with 512MB/1GB RAM, 4GB NAND Flash, 10/100 MBit Ethernet, HDMI output, 2x USB Host port, 1x USB OTG port, a microSD socket, a SATA interface, an IR sensor and 2 headers to access extra pins such as GPIOs, I2C, SPI,VGA pins, CVBS pins etc… CubieTech had a successful Indiegogo campaign where the 1GB board was available for $59 including worldwide shipping (and as low as $19 for early birds), and you can now buy it from resellers. [Update: It’s now available with several cables, USB to TTL debug board, and an enclosure for $80 on dx.com] Cubieboard Unboxing The board comes with a SATA cable and a USB cable for power. There’s no power supply so you’ll need you […]

Posted on by Jean-Luc Aufranc (CNXSoft) - 5 Comments on Big.LITTLE Processing Implementations and Current Status

Big.LITTLE Processing Implementations and Current Status

There was a big,LITTLE mini-summit during Linaro Connect Europe 2012, where an update was given on current big.LITTLE implementations and the results of measurement of power vs performance. Big.LITTLE Processing Implementations Overview As briefly mentioned in “Versatile Express TC2 (2xA15, 3xA7) Development Board at ARM Techcon 2012“, there are 2 big.LITTLE implementations: In-kernel switcher (IKS) This implementation is already available through Linaro and only required minimal changed to the kernel as it mainly an augmentation to DVFS (Dynamic Voltage and Frequency Scaling) except instead of only adjusting voltage and frequency depending on the load, it will also move the load to different cores. The main drawback is that this implementation only uses half the cores. For example, on a 2x Cortex A15 / 2x Cortex A7 system, it can only use 2 cores at the same time (either A15 or A7 cores), as the load is managed between one type […]