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

You might want to take a look at the list of Frequently Asked Questions before asking questions on the mailing list...

### 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

- 9 August 2002, uClibc 0.9.13 Released
  CodePoet Consulting is pleased to announce the immediate availability of uClibc 0.9.13. After several days of testing, this release is looking very solid. This release fixes three security vulnerabilites in previous releases. There was an off-by-one buffer overflow in the group handling code, and integer overflows in calloc() and xdr_array().

  This release adds native shared library support for the Hitachi SuperH architecture, thanks to Stefan Allius and Edie C. Dost. A new mmap based malloc was implemented by Miles Bader. This is much smarter than the old "malloc-simple" and is now the default for mmu-less systems, where it should greatly help reduce memory fragmentation and wastage. In addition to these larger items, there has been a lot of work done to make uClibc a cleaner, more capable, library. Most applications now compile and run without any trouble.

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

  Have fun!

- 9 August 2002, uClibc now mirrored on kernel.org!
  uClibc is now available from the kernel.org mirrors! This should make uClibc downloads much faster. The kernel.org mirrors will have all uClibc release versions (everything but the daily snapshots). Here is a list of all the kernel.org mirror sites. Just pick the closest mirror site, and then go to "/pub/linux/libs/uclibc/" to download uClibc. For example, is you live the USA, you can go to http://www.us.kernel.org/pub/linux/libs/uclibc/ to download the latest uClibc release from a nice fast system.

- 11 July 2002, Native uClibc toolchains updated
  CodePoet Consulting (i.e. Erik) has released updated native uClibc/gcc-3.1 and uClibc/gcc-2.95 toolchains. These toolchains build real gcc cross compilers (i.e. not just a wrapper) and create executables linked vs uClibc. These toolchains have been tested and found working on x86, arm, and mmu-less arm. They should work (at least in theory!) for all architectures supported by uClibc.

  These toolchains should make it easy to 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 demand when you compile things. To build the 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-3.1 toolchain (w/C++ support) on his Athlon XP 1600 (not counting the time it takes to download source code). Your results may vary...

- 20 June 2002, uClibc 0.9.12 Released
  CodePoet Consulting is pleased to announce the immediate availability of uClibc 0.9.12. This release adds an i960 port, an initial alpha port, fully working mips shared library support, shared library support fixes for on powerpc, and many other improvements. One very exciting new feature is nearly complete locale support, thanks to a lot of hard work by Manuel Novoa III. uClibc's locale support is much smaller than glibc's, though it is also slightly less flexible. This release was delayed by a month due to the arrival of a new baby at Erik's house. For those that have been anxiously waiting, this release should certainly be worth the wait. Have fun!

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

- 28 May 2002, Native uClibc/gcc-3.1 toolchain
  CodePoet Consulting has released source code and a Makefile to build a gcc-3.1 toolchain that natively targets uClibc. Additionally, the gcc-3.0.4 and gcc-2.95 toolchains have also been updated. These toolchains make it easy to build uClibc based applications. Source code can be downloaded here and is now much smaller, since much of the needed binutils and gcc source code is now downloaded on demand. To build the toolchain, simply grab the source, edit the Makefile to select where you would like the toolchain installed, and then run 'make' and wait for it to compile.

- 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 applications such as iproute2 and XFree86 to link properly. 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 working applications list .

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

- 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 new snapshot of the source is made daily and is available here
- uClibc has its own publically browsable CVS tree with anonymous CVS access, and for those that are actively contributing there is even CVS write access.

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 |  |  |  |  |