Resource: LCA14 Name: LCA14-501: GLIBC & EGLIBC Date: 07-03-2014 Speaker: Ryan Arnold Video: https://www.youtube.com/watch?v=_xAo1zvmyC8 Website: http://www.linaro.org/ Linaro Connect: http://connect.linaro.org/ Slide: https://www.slideshare.net/linaroorg/lca14-14501-glibceglibc

1. Ryan Arnold, LCA14, Macau
LCA14-14-501: GLIBC & EGLIBC

2. • Eglibc 2.19 has been created (Feb, 7 2014)
• Eglibc 2.19 is the last eglibc release
[Patches] EGLIBC 2.19 set up (last release branch), EGLIBC trunk now closed
From: Joseph Myers
Date: Fri, 7 Feb 2014 21:45:09 +0000
http://www.eglibc.org/archives/patches/msg01327.html
• Glibc is the future!
Eglibc is being retired

3. • glibc release cycle is 6 months +/- 2 months.
• glibc 2.19 released on Feb 7, 2014.
• glibc 2.20 Sept, or Oct.
How long do we have?

4. • ‘E’ stands for Embedded
• Created in 2006
• For embedded software/hardware providers.
• Reduced library size.
• Improved cross compilation and cross debugging.
• Glibc did not accept embedded changes.
History of Eglibc

5. • Past flash memory constraints & RAM constraints.
• Ubuntu on ARM - early consumer of Linaro’s
toolchain.
Why is Linaro using Eglibc?
Debian:
eglibc
Ubuntu:
eglibc
Linaro:
eglibc

6. • Glibc community leadership sea change.
• Embedded is no longer a dirty word in glibc.
• The Eglibc maintainer principle glibc maintainer.
• Cross building features glibc.
• ARM hardware has increased capacity in cycles, RAM,
and Flash Memory.
Why is Eglibc no longer needed?

7. • No, eglibc has always been glibc.
• But, your applications might get a bit bigger.
Is this scary?

8. • Option group users will have larger libraries.
• Option group users will have larger static binaries..
Is there risk?

9. • Glibc, the parent project.
• Newlib or uClibc
What’s the Alternative?

10. • System glibc version Linaro toolchain glibc version.
• Mentor/CodeSourcery will be moving to glibc.
• Canonical will be moving to glibc for Ubuntu.
It’s not just us

11. • Linaro GCC 4.9 toolchain (July 2014)
• Track current stable glibc release starting with glibc 2.19.
• Linaro GCC 4.8 toolchain (July 2014)
• Freeze on eglibc 2.19 and accept critical backports.
• Linaro GCC 4.7 toolchain (July 2014)
• no release - leave support frozen on eglibc 2.19.
What’s Linaro’s release plan with eglibc?

12. • Linaro will start to maintain an upstream glibc branch:
• linaro/X.Y/master
Linaro Upstream Glibc Branch

13. • Option Group Support
• Cross-localedef
• Some features not relevant to ARM.
What’s being left behind?

14. • Get a formalized request.
• Propose configure flags for selective removal to glibc
community.
• Is glibc the right c-library for your application?
But We Use That!

15. • Aarch64 Stack Smashing Protector
• Malloc Benchmarking Integrated in glibc.
• Malloc replacement?
• Testsuite Improvement.
• ports/ promotion into main repository.
Looking Forward: Glibc 2.20

16. • eglibc 2.19 is the last eglibc release.
• Glibc is the replacement.
• This isn’t scary.
• First Linaro toolchain with glibc 2.19 in July.
Questions?
Conclusion

17. More about Linaro Connect: http://connect.linaro.org
More about Linaro: http://www.linaro.org/about/
More about Linaro engineering: http://www.linaro.org/engineering/
Linaro members: www.linaro.org/members