%general-entities; ]> glibc &glibc-version;
&glibc-url;
Glibc-&glibc-version; Glibc <para>The Glibc package contains the main C library. This library provides the basic routines for allocating memory, searching directories, opening and closing files, reading and writing files, string handling, pattern matching, arithmetic, and so on.</para> <segmentedlist> <segtitle>&buildtime;</segtitle> <segtitle>&diskspace;</segtitle> <seglistitem> <seg>&glibc-ch6-sbu;</seg> <seg>&glibc-ch6-du;</seg> </seglistitem> </segmentedlist> </sect2> <sect2 role="installation"> <title>Installation of Glibc Some packages outside of LFS suggest installing GNU libiconv in order to translate data from one encoding to another. The project's home page () says This library provides an iconv() implementation, for use on systems which don't have one, or whose implementation cannot convert from/to Unicode. Glibc provides an iconv() implementation and can convert from/to Unicode, therefore libiconv is not required on an LFS system. The Glibc build system is self-contained and will install perfectly, even though the compiler specs file and linker are still pointing at /tools. The specs and linker cannot be adjusted before the Glibc install because the Glibc autoconf tests would give false results and defeat the goal of achieving a clean build. In the vi_VN.TCVN locale, bash enters an infinite loop at startup. It is unknown whether this is a bash bug or a Glibc problem. Disable installation of this locale in order to avoid the problem: sed -i '/vi_VN.TCVN/d' localedata/SUPPORTED First apply two patches which correct failures in the test suite: patch -Np1 -i ../&glibc-iconv-test-fixes-patch; patch -Np1 -i ../&glibc-ildoubl-test-fix-patch; The ldd shell script contains Bash-specific syntax. Change its default program interpreter to /bin/bash in case another /bin/sh is installed as described in the Shells chapter of the BLFS book: sed -i 's|@BASH@|/bin/bash|' elf/ldd.bash.in The Glibc documentation recommends building Glibc outside of the source directory in a dedicated build directory: mkdir -v ../glibc-build cd ../glibc-build Again, add the needed compiler flags to CFLAGS for x86 machines: case `uname -m` in i?86) echo "CFLAGS += -march=i486 -mtune=native" > configparms ;; esac Prepare Glibc for compilation: ../glibc-&glibc-version;/configure --prefix=/usr \ --disable-profile --enable-add-ons \ --enable-kernel=2.6.0 --libexecdir=/usr/lib/glibc The meaning of the new configure options: --libexecdir=/usr/lib/glibc This changes the location of the pt_chown program from its default of /usr/libexec to /usr/lib/glibc. Compile the package: make In this section, the test suite for Glibc is considered critical. Do not skip it under any circumstance. Before running the tests, copy a file from the source tree into our build tree to prevent a couple of test failures, then test the results: cp -v ../glibc-&glibc-version;/iconvdata/gconv-modules iconvdata make -k check 2>&1 | tee glibc-check-log grep Error glibc-check-log You will probably see an expected (ignored) failure in the posix/annexc test. In addition the Glibc test suite is somewhat dependent on the host system. This is a list of the most common issues: The nptl/tst-cancel1 test will fail when using the 4.1 series of GCC. The nptl/tst-clock2 and tst-attr3 tests sometimes fail. The reason is not completely understood, but indications are that a heavy system load can trigger these failures. The math tests sometimes fail when running on systems where the CPU is not a relatively new genuine Intel or authentic AMD processor. If you have mounted the LFS partition with the noatime option, the atime test will fail. As mentioned in , do not use the noatime option while building LFS. When running on older and slower hardware or on systems under load, some tests can fail because of test timeouts being exceeded. Though it is a harmless message, the install stage of Glibc will complain about the absence of /etc/ld.so.conf. Prevent this warning with: touch /etc/ld.so.conf Install the package: make install The locales that can make the system respond in a different language were not installed by the above command. None of the locales are required, but if some of them are missing, testsuites of the future packages would skip important testcases. Individual locales can be installed using the localedef program. E.g., the first localedef command below combines the /usr/share/i18n/locales/cs_CZ charset-independent locale definition with the /usr/share/i18n/charmaps/UTF-8.gz charmap definition and appends the result to the /usr/lib/locale/locale-archive file. The following instructions will install the minimum set of locales necessary for the optimal coverage of tests: mkdir -pv /usr/lib/locale localedef -i cs_CZ -f UTF-8 cs_CZ.UTF-8 localedef -i de_DE -f ISO-8859-1 de_DE localedef -i de_DE@euro -f ISO-8859-15 de_DE@euro localedef -i de_DE -f UTF-8 de_DE.UTF-8 localedef -i en_HK -f ISO-8859-1 en_HK localedef -i en_PH -f ISO-8859-1 en_PH localedef -i en_US -f ISO-8859-1 en_US localedef -i en_US -f UTF-8 en_US.UTF-8 localedef -i es_MX -f ISO-8859-1 es_MX localedef -i fa_IR -f UTF-8 fa_IR localedef -i fr_FR -f ISO-8859-1 fr_FR localedef -i fr_FR@euro -f ISO-8859-15 fr_FR@euro localedef -i fr_FR -f UTF-8 fr_FR.UTF-8 localedef -i it_IT -f ISO-8859-1 it_IT localedef -i ja_JP -f EUC-JP ja_JP localedef -i tr_TR -f UTF-8 tr_TR.UTF-8 localedef -i zh_CN -f GB18030 zh_CN.GB18030 In addition, install the locale for your own country, language and character set. Alternatively, install all locales listed in the glibc-&glibc-version;/localedata/SUPPORTED file (it includes every locale listed above and many more) at once with the following time-consuming command: make localedata/install-locales Then use the localedef command to create and install locales not listed in the glibc-&glibc-version;/localedata/SUPPORTED file in the unlikely case you need them. Configuring Glibc /etc/nsswitch.conf /etc/localtime The /etc/nsswitch.conf file needs to be created because, although Glibc provides defaults when this file is missing or corrupt, the Glibc defaults do not work well in a networked environment. The time zone also needs to be configured. Create a new file /etc/nsswitch.conf by running the following: cat > /etc/nsswitch.conf << "EOF" # Begin /etc/nsswitch.conf passwd: files group: files shadow: files hosts: files dns networks: files protocols: files services: files ethers: files rpc: files # End /etc/nsswitch.conf EOF One way to determine the local time zone, run the following script: tzselect After answering a few questions about the location, the script will output the name of the time zone (e.g., America/Edmonton). There are also some other possible timezones listed in /usr/share/zoneinfo such as Canada/Eastern or EST5EDT that are not identified by the script but can be used. Then create the /etc/localtime file by running: cp -v --remove-destination /usr/share/zoneinfo/<xxx> \ /etc/localtime Replace <xxx> with the name of the time zone selected (e.g., Canada/Eastern). The meaning of the cp option: --remove-destination This is needed to force removal of the already existing symbolic link. The reason for copying the file instead of using a symlink is to cover the situation where /usr is on a separate partition. This could be important when booted into single user mode. Configuring the Dynamic Loader /etc/ld.so.conf By default, the dynamic loader (/lib/ld-linux.so.2) searches through /lib and /usr/lib for dynamic libraries that are needed by programs as they are run. However, if there are libraries in directories other than /lib and /usr/lib, these need to be added to the /etc/ld.so.conf file in order for the dynamic loader to find them. Two directories that are commonly known to contain additional libraries are /usr/local/lib and /opt/lib, so add those directories to the dynamic loader's search path. Create a new file /etc/ld.so.conf by running the following: cat > /etc/ld.so.conf << "EOF" # Begin /etc/ld.so.conf /usr/local/lib /opt/lib # End /etc/ld.so.conf EOF Contents of Glibc Installed programs Installed libraries catchsegv, gencat, getconf, getent, iconv, iconvconfig, ldconfig, ldd, lddlibc4, locale, localedef, mtrace, nscd, pcprofiledump, pt_chown, rpcgen, rpcinfo, sln, sprof, tzselect, xtrace, zdump, and zic ld.so, libBrokenLocale.{a,so}, libSegFault.so, libanl.{a,so}, libbsd-compat.a, libc.{a,so}, libcidn.so, libcrypt.{a,so}, libdl.{a,so}, libg.a, libieee.a, libm.{a,so}, libmcheck.a, libmemusage.so, libnsl.{a,so}, libnss_compat.so, libnss_dns.so, libnss_files.so, libnss_hesiod.so, libnss_nis.so, libnss_nisplus.so, libpcprofile.so, libpthread.{a,so}, libresolv.{a,so}, librpcsvc.a, librt.{a,so}, libthread_db.so, and libutil.{a,so} Short Descriptions catchsegv Can be used to create a stack trace when a program terminates with a segmentation fault catchsegv gencat Generates message catalogues gencat getconf Displays the system configuration values for file system specific variables getconf getent Gets entries from an administrative database getent iconv Performs character set conversion iconv iconvconfig Creates fastloading iconv module configuration files iconvconfig ldconfig Configures the dynamic linker runtime bindings ldconfig ldd Reports which shared libraries are required by each given program or shared library ldd lddlibc4 Assists ldd with object files lddlibc4 locale Prints various information about the current locale locale localedef Compiles locale specifications localedef mtrace Reads and interprets a memory trace file and displays a summary in human-readable format mtrace nscd A daemon that provides a cache for the most common name service requests nscd pcprofiledump Dumps information generated by PC profiling pcprofiledump pt_chown A helper program for grantpt to set the owner, group and access permissions of a slave pseudo terminal pt_chown rpcgen Generates C code to implement the Remote Procedure Call (RPC) protocol rpcgen rpcinfo Makes an RPC call to an RPC server rpcinfo sln A statically linked ln program sln sprof Reads and displays shared object profiling data sprof tzselect Asks the user about the location of the system and reports the corresponding time zone description tzselect xtrace Traces the execution of a program by printing the currently executed function xtrace zdump The time zone dumper zdump zic The time zone compiler zic ld.so The helper program for shared library executables ld.so libBrokenLocale Used internally by Glibc as a gross hack to get broken programs (e.g., some Motif applications) running. See comments in glibc-&glibc-version;/locale/broken_cur_max.c for more information libBrokenLocale libSegFault The segmentation fault signal handler, used by catchsegv libSegFault libanl An asynchronous name lookup library libanl libbsd-compat Provides the portability needed in order to run certain Berkeley Software Distribution (BSD) programs under Linux libbsd-compat libc The main C library libc libcidn Used internally by Glibc for handling internationalized domain names in the getaddrinfo() function libcrypt libcrypt The cryptography library libcrypt libdl The dynamic linking interface library libdl libg Dummy library containing no functions. Previously was a runtime library for g++ libg libieee Linking in this module forces error handling rules for math functions as defined by the Institute of Electrical and Electronic Engineers (IEEE). The default is POSIX.1 error handling libieee libm The mathematical library libm libmcheck Turns on memory allocation checking when linked to libmcheck libmemusage Used by memusage to help collect information about the memory usage of a program libmemusage libnsl The network services library libnsl libnss The Name Service Switch libraries, containing functions for resolving host names, user names, group names, aliases, services, protocols, etc. libnss libpcprofile Contains profiling functions used to track the amount of CPU time spent in specific source code lines libpcprofile libpthread The POSIX threads library libpthread libresolv Contains functions for creating, sending, and interpreting packets to the Internet domain name servers libresolv librpcsvc Contains functions providing miscellaneous RPC services librpcsvc librt Contains functions providing most of the interfaces specified by the POSIX.1b Realtime Extension librt libthread_db Contains functions useful for building debuggers for multi-threaded programs libthread_db libutil Contains code for standard functions used in many different Unix utilities libutil