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

- 30 June 2003, uClibc 0.9.20 Released
  CodePoet Consulting is pleased to announce the immediate availability of uClibc 0.9.20. This is primarily a bug-fix release. This release remains binary compatible with 0.9.18 and 0.9.19, so you don't have to recompile everything if you don't really feel like it.

  This release has many small improvements. At this point, most applications that compile and work with glibc will also compile and run with uClibc. Perl and Python even pass all the tests in their test suites.

  There is currently one notable exception. Applications with use dlopen() to load libraries that themselves depend on other libraries, may have weak symbols within those depended-upon libraries resolved incorrectly. This problem is currently being worked on. Other than that, everything seems to be working. And everything seems to now be working as expected....

  As usual, the Changelog, detailed changelog, and source code for this release are available here.

- 30 June March 2003, dev systems updated to uClibc 0.9.20
  The uClibc development systems for i386, powerpc, arm, mips, have been updated to uClibc 0.9.20. Several problems have been fixed up, gcc has been updated to version 3.3, and Perl 5.8.0 is now included.

  This is a 150 MB ext2 filesystem that runs natively on the specified architecture. It contains all the development software you need to build your own uClibc applications, including bash, coreutils, findutils, diffutils, patch, sed, ed, flex, bison, file, gawk, tar, grep gdb, strace, make, gcc, g++, autoconf, automake, ncurses, zlib, openssl, openssh perl, and more. And of course, everything is dynamically linked against uClibc. By using a uClibc only system, you can avoid all the painful cross-configuration problems that have made using uClibc somewhat painful in the past. If you want to quickly get started with testing or using uClibc you should give these images a try. You can loop mount and then chroot into them, you can boot into them using user-mode Linux, and you can even 'dd' them to a spare partition and use resize2fs to make them fill the drive. Whatever works for you.

  If you would like to build your own custom uClibc system, you can use buildroot, which is how the uClibc development systems were created.

- 6 March 2003, development system updates
  The uClibc development systems for i386, powerpc, arm, and now for the first time mips, have been updated to uClibc 0.9.19. Several smaller problems have also been fixed up.

  This is an ext2 filesystem that runs natively on the specified architecture. It contains all the development software you need to build your own uClibc applications, including bash, coreutils, findutils, diffutils, patch, sed, ed, flex, bison, file, gawk, tar, grep gdb, strace, make, gcc, g++, autoconf, automake, ncurses, zlib, openssl, openssh and more. And of course, everything is dynamically linked against uClibc. By using a uClibc only system, you can avoid all the painful cross-configuration problems that have made using uClibc somewhat painful in the past. If you want to quickly get started with testing or using uClibc you should give these images a try. You can loop mount and then chroot into them, you can boot into them using user-mode Linux, you can even 'dd' them to a spare partition and use resize2fs to make them fill the drive. Whatever works best for you.

  Have Fun.

- 3 March 2003, uClibc 0.9.19 Released
  CodePoet Consulting is pleased to announce the immediate availability of uClibc 0.9.19. This is once again primarily a bug-fix release. Several critical problems with system calls were fixed, the pthreads library was improved, debugging of applications using uClibc's pthreads library is now possible (requires gdb 5.3 or newer that is compiled using uClibc), and a number of other random fixes are included. This release retains binary compatibility with uClibc 0.9.18 (except for mips, which didn't work properly with uClibc 0.9.18 anyways). Updated development system images compiled with uClibc 0.9.19 will be released shortly.

  As usual, 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).

- Penguru Consulting
  Custom development for embedded Linux systems and multimedia platforms
- opensource.se
  Embedded open source consulting in Europe.
- 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
- You may want to download uClibc from the closest kernel.org mirror site. Just pick the closest mirror site, and then go to the /pub/linux/libs/uclibc/ directory to download uClibc.
- 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.

Toolchains

- Steven J. Hill has kindly provided RPMs and SRPMs with toolchains for mips.
- You can build your own uClibc toolchain using these Makefiles which automagically download all the source needed code and compile it for you.
- uClibc development systems for i386 and powerpc, and arm are available and contain complete gcc 3.2.2 toolchains.
- You can compile your own uClibc development system using buildroot.

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 |  |  |  |  |