CEWG-update-2011-05-Jamboree37 - eLinux.org

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Dec 10, 2013 (3 years and 8 months ago)

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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

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 3
rd

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!