Archive

Posts Tagged ‘ubifs’

UBI Fastmap – ELCE 2012

January 17th, 2013 No comments

Thomas Gleixner, Linux kernel programmer at Linutronix, talks about UBI flash management layer, and fastmap implementation to speed up boot times at the Embedded Linux Conference Europe, on November 7, 2012.

Abstract:

UBI is a flash management layer in the Linux kernel designed to handle especially the shortcomings of NAND flash. UBI itself has the requirement to scan the full flash at boot time. With flash sizes becoming larger and larger this can take quite some time. A recent development implemented fast mapping functionality which is designed to put an upper bound on the number of flash eraseblocks to scan. This allows faster boot times without sacrifying the robustness of UBI. This talk gives an overview of the UBI fastmap design and looks at costs and benefits.

UBIFS

The talk provides an overview of UBI and its shortcomings, and explains UBI fastmap implementation in details showing it provides significant speedup proportional to the flash size. UBI fastmap has been merged in Kernel 3.7.

You can also download the presentation slides for this talk.

Digg This
Reddit This
Stumble Now!
Buzz This
Vote on DZone
Share on Facebook
Bookmark this on Delicious
Kick It on DotNetKicks.com
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter

Status of Embedded Linux – ELC 2012

February 26th, 2012 No comments

Tim Bird, software engineer at Sony, discusses recent development in embedded Linux at the Embedded Linux Conference 2012.

Abstract:  Tim discusses changes to the kernel, improvements to embedded-related sub-systems, and new industry initiatives likely to affect embedded Linux developers in the future. Also, Tim discusses the direction of the Linux Foundation CE Workgroup, and their contract work and projects for this year. Last year highlights are also discussed, as well as ways to continue to improve Linux going forward.

Here are the key points of this presentation:

  • Linux Kernel Version changes: 2.6.38 to 3.3-rc3
  • Technology Areas:
    • Bootup Time  – With improvement in the kernel, bootloader and user-space
    • Graphics – 2D/3D implementation. New /dev/ion and CMA graphics stuffs
    • Accelerated Rendering – e.g. Renderscript
    • Graphics Drivers – e.g. PowerVR
    • Multimedia – Gstreamer, Android Media Layer (stagefright) and codec wars (e.g. patent issues with WebM/VP8 that interferes open source licenses).
    • File systems – Mainly UBIFS (default raw flash file system replacing JFFS2) and YAFFS2. But Google is moving to ext-4 with eMMC devices.
    • Power Management
    • System Size – Work is still going on on low footprint distros such as linux-tiny and poky-tiny.

    The hot areas right now are power management, ARM board support refactoring and GPU management.

  • CE Workgroup Projects:
  • Miscellaneous:
    • Tools:
      • Qemu for Linux and Android emulation
      • Eclipse
      • Tracing tools (Perf, ftrace, LTTng 2.0)
    • Build Systems: Yocto project and custom build systems.
    • Embedded Distributions:
      • Tizen
      • WebOS
      • Legacy Custom embedded distros (no standard)
    • Android 4.0 SDK release (last October)
    • Resources:
      • Stack Overflow is used more and more for embedded Linux
      • elinux.org Wiki has got a lot of good documentation
      • LWN.net to follow kernel changes.

You can also download the presentation slides on elinux.org.

Digg This
Reddit This
Stumble Now!
Buzz This
Vote on DZone
Share on Facebook
Bookmark this on Delicious
Kick It on DotNetKicks.com
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter