uClibc - a Small C Library for Linux
Erik Andersen
uClibc (aka Clibc/pronounced yew-see-lib-see) is a size-optimized
implementation of the standard C library. It is primarily designed
for developing 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
even supports shared libraries and threading. It currently runs on
standard Linux and MMU-less (also known as ClinuxClinux) systems
with support for ARM, i386, h8300, m68k, mips, mipsel, PowerPC, SH,
SPARC, and v850 processors.
For installation instructions, see the file INSTALL.
This distribution contains a wrapper for gcc and ld that allows you
to use existing toolchains that were targetted for glibc. See
extra/gcc-uClibc/ for information.
uClibc strives to be standards compliant, which means that most
documentation written for functions in glibc also apply to uClibc
functions. However, many GNU extensions are not supported because
they have not been ported, or more importantly, would increase the
size of uClibc disproportional to the added functionality.
Additional information (recent releases, FAQ, mailing list, bugs,
etc.) can be found at http://www.uclibc.org/.
uClibc may be freely modified distributed under the terms of the
GNU Library General Public License, which can be found in the
file COPYING.LIB.
Please Note:
There is an unwholesomely huge amount of code out there
that depends on the presence of GNU libc header files.
We have GNU libc header files. So we have committed a
horrible sin in uClibc. We _lie_ and claim to be GNU
libc in order to force these applications to work as their
developers intended. This is IMHO, pardonable, since
these defines are not really intended to check for the
presence of a particular library, but rather are used to
define an _interface_. Some programs (such as GNU
binutils) are especially chummy with glibc, and need this
behavior disabled by adding CFLAGS+=__FORCE_NOGLIBC