Tim Bird, senior staff software engineer at Sony Network Entertainment, hosts a BoF session about tools & methods for embedded Linux developers at ELCE 2012. Abstract: In this Birds-of-a-Feather-session, Tim will share some of his favorite tips for developing embedded Linux software. This will include tips for using ‘git’, how he does multi-platform development, and tips for other tools that other developers might find useful. Prior to the event, Tim will do a survey and solicit ideas from other developers as well. Please come to this BoF prepared to share your own productivity tips for embedded Linux development. Tim talks is divided into the following key points: Git tips – How to finds info about commits (git log, git show), use aliases (e.g. for colored output), find a commit that caused problem (git bisect), and more Patch management – quilt patch managing tool, diffinfo, and splitpatch (to break patches apart) […]
USB Debugging and Profiling Techniques – ELCE 2012
Kishon Vijay Abraham and Basak Partha, respectively software design engineer and tech lead at Texas Instruments, provide an overview of techniques that can be used to debug Linux USB drivers on the host PC or/and the device itself. Abstract: The widespread integration of USB into embedded applications presents many developers with the challenge of debugging problems, that are difficult to detect and isolate when a USB device misbehaves. This paper discusses about the various USB debugging techniques which includes debugging at the host PC, at the device and in the cable and discuss when each of the above techniques will be handy. This paper will also discuss about the various facilities provided within Linux kernel to aid in USB debugging e.g sysfs, trace points etc. and the various user space tools available to help USB debugging e.g USBMON. This paper also discusses about the profiling techniques at various levels in […]
OpenOCD: Hardware Debugging and More – ELCE 2012
Peter Stuge, self-employed hardware, software and security consultant, talks about OpenOCD open source tool for JTAG debugging at ELCE 2012 in Barcelona. Abstract: The presentation walks through how to use the OpenOCD open source software to debug embedded systems on the hardware level via JTAG interface, allowing single stepping, setting breakpoints, inspecting register and memory contents and more, starting before the CPU even executes the first instruction. After an introduction to JTAG debugging we look at how to use OpenOCD both standalone for firmware flashing as well as together with the GDB GNU Debugger for convenient debugging of bootloaders or the Linux kernel. These tasks will be demonstrated, and the respective OpenOCD configuration details will be explained.The presentation targets intermediate-level developers who work on bootloaders, BSPs and kernel drivers, deeply embedded systems, and test and production engineers with an interest in using OpenOCD, which can allow unified tooling across all […]
F2FS – A New Flash File System for Mobile Devices – ELCE 2012
Joo-Young Hwang, principal engineer at Samsung, presents F2FS (Flash-Friendly File System), a new file system designed for storage in mobile devices at the Embedded Linux Conference in Barcelona, Spain, on November 5, 2012. Abstract: Recent mobile devices adopt various flash storages as a primary storage. File system support for those flash storages is a must for flash device performance and lifespan. I will present a new file system, called F2FS, designed for mobile flash storages. F2FS is designed considering the characteristics of the underlying flash storage which has flash translation layer (FTL). F2FS outperforms EXT4, which is a popular file system for Android phones, in most of benchmarks. I will describe motivation, design, and implementation of the file system, then show performance comparison data with EXT4. Target audiences are those who are interested in file system support for flash storages such as eMMC and SSD. Kernel and file system expertise […]
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 […]
Piglit OpenGL Driver Testing Framework Now Works with ARM Linux & OpenGL ES
Piglit is a collection of automated tests for OpenGL implementations that aims at improving the quality of open source OpenGL drivers by providing developers with a simple means to perform regression tests. ARM SoCs that come with a GPU usually (always?) supports OpenGL ES however. That’s why, Tom Gall (Linaro) has modified Piglit in order to bring this test suite to ARM Linux and OpenGL ES. There are about 6,900 OpenGL tests in Piglit, and currently 1,047 Piglit (OpenGL ES) tests can run on ARM . Tom also explains that piglit developers are now using waffle, a cross-platform C library that allows one to defer selection of GL API and window system until runtime. This will allow your to select the variation of the GL API (GL, GL ES) and windowing system (X11, Wayland…) you want to use at runtime. The code is still heavily modified, but it’s in the […]
ZOPO ZP900S Leader Smartphone Unboxing and Review
I’ve just received ZOPO ZP900S smartphone from Pandawill by Fedex. This phablet features a 5.3″ display, MediaTek MTK6577 dual core cortex A9 processor with 512 MB RAM, 4GB flash and runs Android 4.0 (upgradable to Android 4.1 once the firmware is released). This is the lite version of ZOPO ZP900 which comes with 1GB RAM. Both devices look like low cost versions of the Samsung Galaxy Note as you can see from the comparison table below between ZOPO ZP900S, ZOPO ZP900 and Samsung Galaxy Note N7000. ZOPO ZP900S & ZP900 Specifications ZOPO ZP900S Leader ZOPO ZP900 Leader Samsung Galaxy Note CPU Mediatek MTK6577 @ 1GHz Samsung Exynos 4210 @ 1.4 GHz GPU POWERVR SGX531T ARM Mali-400MP RAM 512 MB 1GB 1GB Storage 4 GB Flash + microSD 16GB/32GB Flash + microSD Display 5.3″ IPS 960×540 (qHD) 5.3″ super AMOLED 1280×800 Camera 8MP Rear, 2MP Front 8MP Rear, 2MP Front Wi-Fi […]
SoC Power Measurement with ARM Energy Probes and Linux EAP Tools
Andy Green, TI Landing Team lead at Linaro, gave an interesting presentation entitled “How to measure SoC power” at Linaro Connect Europe 2012. This talk was specifically aimed at software engineers, so that they know how to properly measure power consumption, and take actions to optimize the software to decrease it. In the first part of the presentation, he gives an overview of electronics basics with definition of voltage, load, current and power, units used for power measurements (Clue: you need to use Watts), and how voltage, current and power can be measured with voltmeters and ammeters. When you want to measure power in a rail, you would usually insert a shun resistor, use a multimeter and derive the power from the resistance and the measured voltage (P=V2/R). He also gives details about regulator efficiency, choosing measurement sampling… There are 4 common measurements strategies: DC IN – Easiest way, gives the complete […]