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 embedded Linux systems. It is much smaller then 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 supports standard Linux architectures (such as x86, strongArm, and powerpc), and also supports MMU-less (also known as µClinux) architectures such as the Coldfire, Dragonball, and ARM7TDMI micro-controllers. 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, then 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
uClibc has a mailing list. To subscribe, go and visit this page.
Known Working Applications List
uClibc now has a list of applications that are known to work. Submissions are welcome! Since most applications work just fine with uClibc, we are especially interested in knowing about any applications that either do not compile at all or do not work properly with uClibc.
Frequently Asked Questions
uClibc now has a list of Frequently Asked Questions. You might want to take a look.
Latest News

- 10 April 2002, uClibc 0.9.11 Released
  CodePoet Consulting is pleased to announce the immediate availability of uClibc 0.9.11. This release is primarily focused on fixing the issues that have turned up since the last release. Several bugs in the gcc wrapper have been fixed, allowing things like iproute2 and XFree86 to link properly now. Large file support has been improved, and a thread locking bug was fixed that could cause s*printf calls to deadlock when threading was enabled. Several bugs were also fixed with the powerpc, h8300, m68k, sparc, and mips architecture support. Many additional applications now compile and run perfectly and have been added to the end of the working applications list .

  The Changelog and source code for this release are available here.

- 10 April 2002, Native uClibc/gcc-3.0.4 toolchain
  CodePoet Consulting has released source code and a Makefile to build a gcc-3.0.4 toolchain that natively targets uClibc. This brings with it full C++ support for uClibc, including the libstdc++ library. A gcc-2.95.x toolchain will also be released shortly, but is not yet ready. At this time, only source code and a Makefile for the native uClibc toolchain is being released (i.e. no binaries, sorry). Source code can be downloaded here, but be aware that the source code is 27 MB.

  To build the toolchain, simply grab the source, edit the Makefile to select where you would like the toolchain installed. Then run 'make and wait for it to compile. If you do not have a copy of uClibc already, it will download the latest daily snapshot.

- 21 March 2002, uClibc 0.9.10 Released!
  CodePoet Consulting is pleased to announce the immediate availability of uClibc 0.9.10. This release adds pthreads support (including pthreads support for mmu-less systems!). Additionally, thanks to Manuel Novoa III, we now have a completely new stdio library, which is small, standards compliant, supports pthreads, wide/narrow streams, large files, and can even operate in a low-memory unbuffered mode. Many, many bugs have been fixed and a number of additional applications now compile and run perfectly. Even with all these changes, uClibc continues to be very small. On x86, a default build of the uClibc C library is still just 168k.

  To make things more interesting, the release also adds support for C++ constructors and destructors. To make it easy to use uClibc when developing C++ applications, this release also provides a wrapper for the GNU C++ compiler. Of course, for more complex C++ applications, such as those using iostreams, a standard C++ library (libstdc++) is required. A native GNU toolchain (binutils/gcc) that provides libstdc++ linked with uClibc 0.9.10 will be released in the next couple of days, so stay tuned.

  The Changelog and Source code for this release are available here.

- 4 February 2002, uClibc 0.9.9 Released!
  CodePoet Consulting is pleased to announce the immediate availability of uClibc 0.9.9. With this release, just about everything we have tested now compiles and runs. In fact, there are now so many programs on the working application list that rather than continue to add to this list, from now on we will only be adding applications to the not working list. Most applications on the not working list either require pthreads, or require wide-character support. Work on wide-character support is well underway, and will hopefully be moving into CVS in the next week or two. Full pthreads support and rentrancy are on the TODO list and are expected to be complete in the next couple of months.

  The Changelog and Source code for this release are available here.

  One final bit on news -- as some of you may have noticed, uclibc.org has been a bit overloaded and somewhat slow recently. The server should be getting colocated tomorrow, which will eliminate the speed problem. During the move, there may be some temporary disruption of service...

  Have Fun!

- 22 December 2001, uClibc 0.9.8 Released!
  After many months of initial development, we are pleased to announce the release of uClibc 0.9.8. This release should be quite solid, and is very usable. This also, hopefully, marks a transition from a slow incubation phase to a more methodical release cycle. From now one, there should be approximately one release per month.

  The source code for this release is available here.

- Old News
  Click here to read older news.

Download

- There is now a script that creates a daily snapshot tarball of uClibc and posts it on here.
- uClibc also has a publicly browsable CVS tree
- Anonymous CVS access is available, and
- For those that are actively contributing there is even CVS write access.

Help Support uClibc development

Do you like uClibc? Do you need support? Do you need some feature added to uClibc? Then why not help out? We are happy to accept donations, provide support contracts, and implement funded feature requests. Additionally, uClibc is looking for corporate sponsors to assist development, pay for bandwidth, and help with hardware donations, especially donations of hardware for non-Intel architectures. Click here to help support uClibc and/or request features.
If you prefer to contact us directly for payments (we have a credit card machine so you can avoid online payments), hardware donations, support requests, etc., you can contact CodePoet Consulting here.

TODO

Here are a few things on the TODO list:

- Shared library support for all supported architectures. We now have our own ld.so, but it needs to be ported to support each architecture.
- Shared library support for mmu-less systems. This is very doable (think of C++ vtables for example), but will take some work.
- Someone (hopefully) needs to volunteer to take the LSB Test Suite, pull out the C library testing stuff, and convert it (perl script, by hand, I don't care how) into a form that is usable without having it take over your entire system (i.e. similar to what is currently in the uClibc test suite). This will be enormously helpful!
- other things as I think of them.

Other 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

- BusyBox

- udhcp

- The uClinux home page

- The uClinux CVS repository

- CodePoet Consulting

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