1: This directory contains the version VERSION release of the GNU C Library.
    2: 
    3: The GNU C Library is the standard system C library for all GNU systems,
    4: and is an important part of what makes up a GNU system.  It provides the
    5: system API for all programs written in C and C-compatible languages such
    6: as C++ and Objective C; the runtime facilities of other programming
    7: languages use the C library to access the underlying operating system.
    8: 
    9: In GNU/Linux systems, the C library works with the Linux kernel to
   10: implement the operating system behavior seen by user applications.
   11: In GNU/Hurd systems, it works with a microkernel and Hurd servers.
   12: 
   13: The GNU C Library implements much of the POSIX.1 functionality in the
   14: GNU/Hurd system, using configurations i[34567]86-*-gnu.
   15: 
   16: When working with Linux kernels, the GNU C Library version 2.4 is
   17: intended primarily for use with Linux kernel version 2.6.0 and later.
   18: We only support using the NPTL implementation of pthreads, which is now
   19: the default configuration.  Most of the C library will continue to work
   20: on older Linux kernels and many programs will not require a 2.6 kernel
   21: to run correctly.  However, pthreads and related functionality will not
   22: work at all on old kernels and we do not recommend using glibc 2.4 with
   23: any Linux kernel prior to 2.6.
   24: 
   25: All Linux kernel versions prior to 2.6.16 are known to have some bugs that
   26: may cause some of the tests related to pthreads in "make check" to fail.
   27: If you see such problems, please try the test suite on the most recent
   28: Linux kernel version that you can use, before pursuing those bugs further.
   29: 
   30: The old LinuxThreads add-on implementation of pthreads for older Linux
   31: kernels is no longer supported, and we are not distributing it with this
   32: release.  Someone has volunteered to revive its maintenance unofficially
   33: for at least a short time for the benefit of those using Linux kernels
   34: older than 2.6, but a working version is not presently available.  When
   35: it is in working condition, we will make it available alongside future
   36: glibc releases.  LinuxThreads will not be supported.
   37: 
   38: The GNU C Library supports these configurations for using Linux kernels:
   39: 
   40:         i[34567]86-*-linux-gnu
   41:         x86_64-*-linux-gnu
   42:         powerpc-*-linux-gnu
   43:         powerpc64-*-linux-gnu
   44:         s390-*-linux-gnu
   45:         s390x-*-linux-gnu
   46:         ia64-*-linux-gnu
   47:         sparc*-*-linux-gnu
   48:         sparc64*-*-linux-gnu
   49: 
   50:         alpha*-*-linux-gnu     Requires Linux 2.6.9 for NPTL
   51:         sh[34]-*-linux-gnu     Requires Linux 2.6.11
   52: 
   53: The code for other CPU configurations supported by volunteers outside of
   54: the core glibc maintenance effort is contained in the separate `ports'
   55: add-on.  You can find glibc-ports-VERSION distributed separately in the
   56: same place where you got the main glibc distribution files.
   57: Currently these configurations are known to work using the `ports' add-on:
   58: 
   59:         arm-*-linux-gnu                Requires Linux 2.6.15 for NPTL, no SMP support
   60:         arm-*-linux-gnueabi    Requires Linux 2.6.16-rc1 for NPTL, no SMP
   61:         mips-*-linux-gnu       Requires Linux 2.6.12 for NPTL
   62:         mips64-*-linux-gnu     Requires Linux 2.6.12 for NPTL
   63: 
   64: The ports distribution also contains code for other configurations that
   65: do not work or have not been maintained recently, but will be of use to
   66: anyone trying to make a new configuration work.  If you are interested
   67: in doing a port, please contact the glibc maintainers; see
   68: http://www.gnu.org/software/libc/ for more information.
   69: 
   70: See the file INSTALL to find out how to configure, build, and install
   71: the GNU C Library.  You might also consider reading the WWW pages for
   72: the C library at http://www.gnu.org/software/libc/.
   73: 
   74: The GNU C Library is (almost) completely documented by the Texinfo manual
   75: found in the `manual/' subdirectory.  The manual is still being updated
   76: and contains some known errors and omissions; we regret that we do not
   77: have the resources to work on the manual as much as we would like.  For
   78: corrections to the manual, please file a bug in the `manual' component,
   79: following the bug-reporting instructions below.  Please be sure to check
   80: the manual in the current development sources to see if your problem has
   81: already been corrected.
   82: 
   83: The file NOTES contains a description of the feature-test macros used
   84: in the GNU C library, explaining how you can tell the library what
   85: facilities you want it to make available.
   86: 
   87: Please see http://www.gnu.org/software/libc/bugs.html for bug reporting
   88: information.  We are now using the Bugzilla system to track all bug reports.
   89: This web page gives detailed information on how to report bugs properly.
   90: 
   91: The GNU C Library is free software.  See the file COPYING.LIB for copying
   92: conditions, and LICENSES for notices about a few contributions that require
   93: these additional notices to be distributed.