uClibc -- a C library for embedded systems

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, cris, 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, then using glibc may make more sense. Unless, for example, that 12 Terabytes will be Network Attached Storage and you plan to burn Linux into the system's firmware... 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
13 November 2003, uClibc 0.9.23 Released CodePoet Consulting is pleased to announce the immediate availability of uClibc 0.9.23. Of course, we are somewhat less than pleased that there were configuration problems in the previous release that made such it necessary to release .23 so quickly. Updated uClibc development systems using uClibc 0.9.23 are being built and will be posted shortly. And Erik has built Debian stable (woody) for x86 with uClibc and it runs great. This release continues to be binary compatible with uClibc 0.9.21 and 0.9.22 -- as long as you pick compatible configuration options. Enabling or disabling things like soft-float, locale, wide char support, or changing cpu optimizations are all good examples of binary incompatible configuration options. If have changed any of those sorts of options (or if you are not sure!) you will need to recompile all your applications and libraries. As usual, the Changelog, detailed changelog, and source code for this release are available here. 8 November 2003, uClibc 0.9.22 Released CodePoet Consulting is pleased to announce the immediate availability of uClibc 0.9.22. This release has been cooking for a couple of months now and is looking quite solid. We have done quite a lot of testing with this release and things are looking good. And Erik has built Debian stable (woody) for x86 with uClibc and it runs great. Expect that to be released in the next few days. This release is binary compatible with uClibc 0.9.21 -- as long as you pick compatible configuration options. Enabling or disabling things like soft-float, locale, wide char support, or changing cpu optimizations are all good examples of binary incompatible configuration options. If have changed any of those sorts of options (or if you are not sure!) you will need to recompile all your applications and libraries. Updated uClibc development systems using uClibc 0.9.22 will be made available within a few days. Meanwhile, we invite you to try out uClibc with the latest Linux Test Project test suite (you will need to apply a small patch. And also give the latest Perl and Python test suites a try as well. If you find any bugs in uClibc, PLEASE let us know! As usual, the Changelog, detailed changelog, and source code for this release are available here. 30 September 2003, dev systems updated to uClibc 0.9.21+ The uClibc development systems for i386, powerpc, arm, mips, have been updated to uClibc 0.9.21 (plus all the CVS updates up to today). Several problems have been fixed up, gcc has been updated to version 3.3.1, binutils was updated to 2.14.90.0.6, and tada everything finally works for cross compiling. These were all cross compiled (which really makes things faster since the older mipsel releases used to take 2 days to build!) These are ~100 MB ext2 filesystems that run natively on the specified architecture. They 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 them you can chroot into them, you can boot into with 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 these uClibc development systems were created. 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 features 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 Embedded Linux Developer Forum CodePoet Consulting

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