µ C l i b c

uClibc -- a C library for embedded systems

uClibc (aka µClibc/pronounced yew-see-lib-see) is a C library for developing embedded Linux systems. It is much smaller than the GNU C Library, but nearly all applications supported by glibc also work perfectly with uClibc. Porting applications from glibc to uClibc typically involves just recompiling the source code. uClibc even supports shared libraries and threading. It currently runs on standard Linux and MMU-less (also known as µClinux) systems with support for alpha, ARM, i386, i960, h8300, m68k, mips/mipsel, PowerPC, SH, SPARC, and v850 processors.

If you are building an embedded Linux system and you find that glibc is eating up too much space, you should consider using uClibc. If you are building a huge fileserver with 12 Terabytes of storage, than using glibc may be a better choice...

uClibc is maintained by Erik Andersen and is licensed under the GNU LIBRARY GENERAL PUBLIC LICENSE . This license allows you to make closed source commercial applications using uClibc (Please consider sharing some of the money you make ;-). You do not need to give away all your source code just because you use uClibc and/or run on Linux.

### Mailing List Information

uClibc has a mailing list.
To subscribe, go and visit this page.

### Frequently Asked Questions

Before asking questions on the uClibc mailing list, you might want to take a look at the list of Frequently Asked Questions or you might want to search the mailing list archives... ...

### Working Applications List

These days, pretty much everything compiles with uClibc. This is a list of applications that are known to work just fine with uClibc. Since most applications work just fine with uClibc, we are especially interested in knowing about any applications that either do not compile or do not work properly with uClibc. Submissions are welcome!

Latest News

- 8 November 2002, uClibc 0.9.16 Released
  CodePoet Consulting is pleased to announce the immediate availability of uClibc 0.9.16. This release adds full support (including a native shared library loader) for the CRIS architecture, contributed by Tobias Anderberg. Stefan Allius contributed a number of patches to fix the initialization order for shared library global constructors and destructors as well as a large number of SuperH fixes and cleanups. uClibc now compiles with newer versions of gcc (i.e. RedHat 8.0). Thanks to Christian Michon, uClibc no longer requires perl to compile. Steven J. Hill fixed dlopen for mips. Several problems with pty and tty handling were fixed. Manuel Novoa added new support for an /etc/TZ file to globally set the system timezone, and fixed up a number of remaining wide char issues. Manuel is still hard at work on bringing full locale support (optional of course) to uClibc. And of course, this release includes the usual pile of bug fixes. Many thanks for the large number of patches and fixes that were contributed!

  Erik and Manuel have been working on a document describing some of the differences between uClibc and glibc. It's not yet 100% complete, and it hasn't been nicely formatted yet. But it contains a lot of helpful information and is worth a look.

  And finally, the the old uClibc configuration system has been completely removed (and there was much rejoicing). It was replaced with an entirely new system based on LinuxKernelConf, which has since been included into Linux 2.5.45, so it looks like Erik made the right choice. Of course, those who have existing build systems using uClibc will need to make a few changes... We think the change is worth it.

  As usual, the Changelog and source code for this release are available here. You might want to download uClibc from the closest kernel.org mirror site. Just pick the closest mirror site, and then go to http://www.XX.kernel.org/pub/linux/libs/uclibc/ to download uClibc, where XX is your two letter country code.

  Updated gcc-3.2 and gcc-2.95 toolchains will be released shortly.

- 16 September 2002, gcc-3.2 and gcc-2.95 toolchains released
  CodePoet Consulting (i.e. Erik) has released updated gcc-3.2 and gcc-2.95 uClibc toolchains. These toolchains build real gcc cross compilers (i.e. not just a wrapper) and create executables linked vs uClibc. The new gcc-3.2 provides uClibc support with the latest and greatest compiler available from the gcc team. The gcc-2.95 toolchain has been updated to the latest version of uClibc and now provides full C++ support, using the STLport standard C++ library.

  This toolchain should make it easy for anyone to build uClibc based applications. Source code can be downloaded here. Be aware that much of the needed source code will actually be downloaded on when you compile the toolchains. To build a toolchain, simply grab the source, edit the Makefile to select where you would like the toolchain installed, run 'make', and then go watch TV, eat dinner, or visit with your friends while it compiles. It takes about 15 minutes for Erik to compile the gcc-3.2 toolchain (w/C++ support) on his Athlon XP 1600 (not counting the time it takes to download source code).

- Old News
  Click here to read older news.

Sponsors

Please visit our sponsors and thank them for their support! They have provided money, equipment, bandwidth, etc. Next time you need help with a project, consider these fine companies! Several individuals have also contributed (If you have contributed and would like your name added here, just email Erik and let him know).

- opensource.se
  Embedded open source consulting in Europe.
- http://i-netinnovations.com/
  Web hosting (currently hosting busybox.net and uclibc.org)
- Lineo
  Embedded Linux development and services.
- Codepoet Consulting
  Custom Linux, embedded Linux, BusyBox, and uClibc development.

Do you like uClibc? Do you need support? Do you need some feature added? Then why not help out? We are happy to accept donations (such as bandwidth, mirrors sites, and hardware for the various architectures). We can also provide support contracts, and implement funded feature requests. To contribute, you can either click on the Donate image to donate using PayPal, or you can contact Erik at CodePoet Consulting (we have a credit card machine so you can avoid PayPal if you wish).

Download

- Source for the latest release can always be downloaded from http://www.uclibc.org/downloads
- A daily snapshot of the source is available for those wishing to follow uClibc developments, but cannot or do not wish to use CVS.
- uClibc has a publically browsable CVS tree.
- Anonymous CVS access is available to let you track development.
- CVS write access is also available for those that are actively contributing.

Other Open Source C libraries:

I am currently aware of the following open source C libraries.

- GNU C Library (aka glibc)
- Al's FREE C Runtime Library
- diet libc
- the minix C library
- newlib
- and there is a C library, for eCos as well.

Links to other useful stuff

- The uClibc home page

- The uClibc CVS tree

- BusyBox

- udhcp

- The uClinux home page

- The uClinux CVS repository

- CodePoet Consulting

Mail all comments, insults, suggestions and bribes to Erik Andersen |  |  |  |  |