1 This directory contains the version VERSION release of the GNU C Library.
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.
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.
13 Version 2.4 is the first release after a long period of development, and
14 introduces changes to the API and a new ABI for all configurations. It
15 has been tested and deployed in new production systems, but should still
16 be considered somewhat experimental. The stable 2.3 release series
17 continues to be maintained, and implements a widely-deployed ABI.
18 Version 2.3.6 is available, and we will release 2.3.7 with more bug fixes.
20 The GNU C Library implements much of the POSIX.1 functionality in the
21 GNU/Hurd system, using configurations i[34567]86-*-gnu.
23 When working with Linux kernels, the GNU C Library version 2.4 is
24 intended primarily for use with Linux kernel version 2.6.0 and later.
25 We only support using the NPTL implementation of pthreads, which is now
26 the default configuration. Most of the C library will continue to work
27 on older Linux kernels and many programs will not require a 2.6 kernel
28 to run correctly. However, pthreads and related functionality will not
29 work at all on old kernels and we do not recommend using glibc 2.4 with
30 any Linux kernel prior to 2.6.
32 All Linux kernel versions prior to 2.6.16 are known to have some bugs that
33 may cause some of the tests related to pthreads in "make check" to fail.
34 If you see such problems, please try the test suite on the most recent
35 Linux kernel version that you can use, before pursuing those bugs further.
37 The old LinuxThreads add-on implementation of pthreads for older Linux
38 kernels is no longer supported, and we are not distributing it with this
39 release. Someone has volunteered to revive its maintenance unofficially
40 for at least a short time for the benefit of those using Linux kernels
41 older than 2.6, but a working version is not presently available. When
42 it is in working condition, we will make it available alongside future
43 glibc releases. LinuxThreads will not be supported.
45 The GNU C Library supports these configurations for using Linux kernels:
47 i[34567]86-*-linux-gnu
57 alpha*-*-linux-gnu Requires Linux 2.6.9 for NPTL
58 sh[34]-*-linux-gnu Requires Linux 2.6.11
60 The code for other CPU configurations supported by volunteers outside of
61 the core glibc maintenance effort is contained in the separate `ports'
62 add-on. You can find glibc-ports-VERSION distributed separately in the
63 same place where you got the main glibc distribution files.
64 Currently these configurations are known to work using the `ports' add-on:
66 arm-*-linux-gnu Requires Linux 2.6.15 for NPTL, no SMP support
67 arm-*-linux-gnueabi Requires Linux 2.6.16-rc1 for NPTL, no SMP
68 mips-*-linux-gnu Requires Linux 2.6.12 for NPTL
69 mips64-*-linux-gnu Requires Linux 2.6.12 for NPTL
71 The ports distribution also contains code for other configurations that
72 do not work or have not been maintained recently, but will be of use to
73 anyone trying to make a new configuration work. If you are interested
74 in doing a port, please contact the glibc maintainers; see
75 http://www.gnu.org/software/libc/ for more information.
77 See the file INSTALL to find out how to configure, build, and install
78 the GNU C Library. You might also consider reading the WWW pages for
79 the C library at http://www.gnu.org/software/libc/.
81 The GNU C Library is (almost) completely documented by the Texinfo manual
82 found in the `manual/' subdirectory. The manual is still being updated
83 and contains some known errors and omissions; we regret that we do not
84 have the resources to work on the manual as much as we would like. For
85 corrections to the manual, please file a bug in the `manual' component,
86 following the bug-reporting instructions below. Please be sure to check
87 the manual in the current development sources to see if your problem has
88 already been corrected.
90 The file NOTES contains a description of the feature-test macros used
91 in the GNU C library, explaining how you can tell the library what
92 facilities you want it to make available.
94 Please see http://www.gnu.org/software/libc/bugs.html for bug reporting
95 information. We are now using the Bugzilla system to track all bug reports.
96 This web page gives detailed information on how to report bugs properly.
98 The GNU C Library is free software. See the file COPYING.LIB for copying
99 conditions, and LICENSES for notices about a few contributions that require
100 these additional notices to be distributed.