status of embedded linux
DESCRIPTION
Status of Embedded Linux. CE Worgroup Work Update May 2011. Tim Bird Architecture Group Chair LF CE Workgroup. Outline. Status of merger with Linux Foundation CELF contract work Review of 2010 work Plan for 2011 work Conferences Other meetings Other initiatives. Merger Status. - PowerPoint PPT PresentationTRANSCRIPT
Status of Embedded Linux
CE WorgroupWork Update
May 2011
Tim Bird
Architecture Group Chair
LF CE Workgroup
Outline
• Status of merger with Linux Foundation• CELF contract work• Review of 2010 work• Plan for 2011 work
• Conferences• Other meetings
• Other initiatives
Merger Status
Merger with Linux Foundation
• Merger was completed in January 2011• Some final legal details still being wrapped
up• CELF is now the Linux Foundation “CE
Workgroup”• Now starting to utilize Linux Foundation
infrastructure– Should mean it's easier for non-members
to participate in CE WG projects!
Contract Work 2010
CELF Contract Work 2010
• Bootchart and smemcap in busybox• Function-sections• YAFFS2 mainline effort• SquashFS enhancements• U-Boot ARM enhancements• Trace format standard• Kexecboot enhancements• Flash filesystem testing
Bootchart and smemcap support in busybox Smemcap applet
• Bootchart applet - Captures bootchart data• See
http://elinux.org/Japan_Technical_Jamboree_33• See http://elinux.org/Bootchart#BusyBox
• Smemcap applet – captures smem data• Data can be moved to host for analysis and
visualization• Contractor: Denys Vlasenko• Status: Completed• Applets are available in busybox mainline
Function-sections
• Description:• Add support to Linux kernel for gcc –ffunction-
sections option, to shrink kernel size by improving dead code removal• Puts each function in its own linker section• Required a big section rename in kernel
• Contractor: Denys Vlasenko• Status:• Most parts mainlined• Waiting to resolve linker issues for weird
symbols on PARISC• Effort stalled – need to finish it
Mainline YAFFS2
• Description:• YAFFS2 is a popular NAND flash filesystem• Was used by Android in many devices
• Add support for YAFFS2 to mainline kernel• Contractor: Aleph One Ltd• Google Co-Sponsored this project• Status:• 3 mainline attempts made, but hit some barriers• Currently stuck on some locking issues
• Outlook for mainline acceptance is uncertain
SquashFS LZMA/LZO Support
Description: LZMA and LZO support
Contractor: Phillip Lougher Status:
LZMA work was submitted, and was in Linux-next, but got rejected
LZO work (contributed by LGE) was mainlined!!
ARM improvements in U-boot
• Description:• Improve aspects of U-boot for ARM• Allow relocating bootloader• Turn caches on for faster booting
• Contractor: Wolfgang Denx• Status:• Work was completed and mainlined in U-Boot
U-Boot Results:
• Limit for boot time into app code is 5s so U-boot image compression was not possible. But now it is.• Results from Matthias Weißer on Aug 5, 2010
• See http://article.gmane.org/gmane.comp.boot-loaders.u-boot/82079
Test Old (icache) New (i+d cache
Improvement
U-boot image size 191K 204K -
Copy 32M NOR -> RAM 7.0s 6.5s x 1.07
iminfo of 1.2 MiB image 0.5s 0.1s x 5.0
bootm of 1.2 MiB gz image 5.4s 0.5s x 10.8
Bootm of 0.8 MiB lzma image 17,1s 1.5s x 11.4
Bootm of 1.6 MiB lzo image 3.2s 0.2s x 16.0
Trace format standard
• Description:• Create a singled trace format standard for the
embedded industry• Contractor: Efficios (Matthieu Desnoyers)• Status:• Standard (Common Trace Format) was created• See http://www.efficios.com/ctf
• BabelTrace trace conversion library• Proof of concept conversion implementation
– Can convert kernel messages with timestamps to CTF and back to text
Kexecboot improvements
Description: Improve user interface and supported storage
devices for kexecboot Contractor: Yuri Bushmelev Status:
Interface has been enhanced Work on reading other storage devices was
completed
Flash filesystem testing
Description: Measure different flash filesystems for
comparisons Contractor: Free Electrons Status:
Results were shown at ELC Europe 2010
Contract Work 2011
Open Project Proposal
• Project ideas were collected in Dec. 2010 and Jan. 2011
• Bids were solicited in March• Architecture Group approved projects in April– 11 projects approved out of 28– Still have budget for more projects
• Contracts are being finalized now• Have a good list, but would like more
proposals from CE WG/LF members
Contract Work 2011
• Improve UBIFS mount time• Mainline Android kernel features• Mainline fast symbol resolution• Work on Linux tiny patches• Support read-only block filesystems on flash
devices
Contract Work 2011 (cont.)
• eLinux wiki content for kernel trace and debug• Mainline the watchdog framework• Flash filesystem testing• Extend bluetooth stack with Remote SIM
Access protocol• Mainline Device Firmware Upgrade (DFU)
code in U-Boot• Solicit project proposals throughout year
Improve UBIFS mount time
• Description:• Add logging or checkpointing to UBI to avoid bad-
block scan of whole device on UBI attach• Contractor: Linutronix (Thomas Gleixner)• Status:• Contract almost finished
Mainline Android kernel features
• Description:• Add a single Android feature (logger) to mainline,
as a pilot project for 3rd party mainlining of Android code
• Longterm goal is to mainline as much of Android as possible, to reduce difference and allow for easier “unified distro kernel”• Kernel that can run Ubuntu, Android, etc.
• Contractor: have interest from Alessio Bogani• Status:• Still working on project plan and bid
Mainline fast symbol resolution
• Description:• Change symbol lookup to use binary search
instead of linear scan• Speeds up module loading
• Contractor: Alessio Bogani• Status:• Patches are in linux-next
Work on Linux tiny patches
Description: Revive Linux-tiny patch set Forward-port patches to latest kernel Add more patches to improve kernel
configurability Contractor: We Zhanjin Status:
Contract ready to sign
Support read-only block filesystems on flash media
Description: Write block emulation layer to support read-only
filesystems on top of MTD layer in kernel Will allow Squashfs to be used on raw NAND
flash media Contractor: Phillip Lougher Status:
Contract in progress
eLinux wiki content for trace and debug
Description: Collect content on kernel trace and debug
techniques and publish on eLinux wiki Contractor: Peter Huewe Status:
Contract ready to sign
Mainline the watchdog framework
Description: Mainline the watchdog framework Original framework was written by Alan Cox and
others Provides a generalized watchdog mechanism Should provide easier method to add
watchdogging to drivers and the kernel going forward
Contractors: Wolfram Sang and Wim van Sebroeck
Status: Contract ready to sign
Flash filesystem testing
Description: Perform mount and runtime performance tests on
multiple flash filesystems, for each new kernel release
Publish results on eLinux wiki Contractor: Free Electrons Status:
Contract ready to sign
Extend bluetooth stack with Remote SIM Access protocol
Description: Allows for Linux bluetooth and telephony stack to
utilize SIM in external device for operation Primary use case is for Linux-based in-car system
to utilize SIM in mobile device for calls, etc. Contractor: ProFusion Status:
Contract almost complete
Mainline Device Firmware Upgrade (DFU) code in U-Boot
Description: Device Firmware Upgrade (DFU) is an industry
standard system for upgrading and manipulating firmware in embedded devices
Add support for this protocol to U-Boot mainline Contractor: Stefan Schmidt Status:
Contract ready to sign
Solicit project proposals throughout the year
Description: CE Workgroup will continue to maintain the
Project Proposal wiki page, and will continue accepting ideas and proposals for contract work through 2011
This will allow ideas to come in as they are generated and relevant, instead of accumulating them throughout the year
Contractor: Bill Traynor Status:
Contract ready to sign
Conferences
Conferences
Past
– ELC 2011 and Android Builders Summit
• Videos just announced – see wiki page
• Kato-san will give a report later today Future
LinuxCon Japan – June 1-3, Yokohama ELC Europe 2011 – Oct 26-28, Prague LinuxCon Brazil – Nov 17-18, Sao Paulo Continuing Japan Jamborees ELC and Android Builders Summit in 2012
See http://events.linuxfoundation.com/ and http://elinux.org/events
Embedded Linux Summit
• Invitation-only event to discuss embedded issues between key industry and community leaders• Was held September 30, 2010 in Tokyo and
October 26 in Cambrige, UK• Similar to other mini-summits, but with focus
on embedded issues• Leading up to kernel summit in November– Has lead to several initiatives– Big one was longterm kernel branch,
maintained by Andi Kleen
Android mainline BOF
• Invitation-only event to discuss Android mainline issues• Was held April 14 in San Francisco– Linaro, CE WG, Google and Qualcomm
attended• Very good discussion about what different
members of the “Android/Linux ecosystem” could do to coordinate work and mainline Android technologies• CE WG “mainline Android logger” project is a
result of this meeting
Other Initiatives
eLinux Wiki
• http://elinux.org/• Wikipedia for embedded Linux developers• Very good for some technical areas• I have been working on Android Portal
section of site• Recently moved to OSU Open Source Lab
hosting• Promotion• Contest – just finished best editor contest!
• Please use it and post stuff
Hardware Donations
• CELF donates hardware for some open source developers• example: Board for BKL removal work
• E-mail me if you need hardware for a project that you think CELF would be interested in
Thanks!