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bluebird 08/12/31 15:17:33 |
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|
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Modified: index.xml |
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Added: multilib.xml |
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Log: |
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Move multilib migration guide from dev space to normal docs space |
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|
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Revision Changes Path |
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1.45 xml/htdocs/proj/en/base/sparc/index.xml |
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|
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file : http://sources.gentoo.org/viewcvs.py/gentoo/xml/htdocs/proj/en/base/sparc/index.xml?rev=1.45&view=markup |
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plain: http://sources.gentoo.org/viewcvs.py/gentoo/xml/htdocs/proj/en/base/sparc/index.xml?rev=1.45&content-type=text/plain |
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diff : http://sources.gentoo.org/viewcvs.py/gentoo/xml/htdocs/proj/en/base/sparc/index.xml?r1=1.44&r2=1.45 |
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|
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Index: index.xml |
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=================================================================== |
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RCS file: /var/cvsroot/gentoo/xml/htdocs/proj/en/base/sparc/index.xml,v |
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retrieving revision 1.44 |
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retrieving revision 1.45 |
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diff -u -r1.44 -r1.45 |
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--- index.xml 14 Nov 2008 20:58:15 -0000 1.44 |
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+++ index.xml 31 Dec 2008 15:17:33 -0000 1.45 |
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@@ -112,6 +112,9 @@ |
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<uri link="qla2xxx.xml">How to get QLA2xxx adapters working with kernel |
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>=2.6.18</uri> |
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</li> |
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+ <li> |
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+ <uri link="multilib.xml">Gentoo Linux SPARC Multilib Migration Guide</uri> |
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+ </li> |
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</ul> |
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|
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<p> |
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|
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|
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|
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1.1 xml/htdocs/proj/en/base/sparc/multilib.xml |
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|
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file : http://sources.gentoo.org/viewcvs.py/gentoo/xml/htdocs/proj/en/base/sparc/multilib.xml?rev=1.1&view=markup |
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plain: http://sources.gentoo.org/viewcvs.py/gentoo/xml/htdocs/proj/en/base/sparc/multilib.xml?rev=1.1&content-type=text/plain |
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|
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Index: multilib.xml |
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=================================================================== |
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<?xml version="1.0" encoding="UTF-8"?> |
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<!DOCTYPE guide SYSTEM "/dtd/guide.dtd"> |
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<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/proj/en/base/sparc/multilib.xml,v 1.1 2008/12/31 15:17:33 bluebird Exp $ --> |
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|
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<guide link="/doc/en/guide.xml" lang="en"> |
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<title>Gentoo Linux SPARC Multilib Migration Guide</title> |
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|
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<author title="Author"> |
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<mail link="bluebird"/> |
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</author> |
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|
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<abstract> |
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This guide will help you to migrate your existing Gentoo Linux SPARC |
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installation from a non-multilib profile to a multilib profile. |
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</abstract> |
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|
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<!-- The content of this document is licensed under the CC-BY-SA license --> |
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<!-- See http://creativecommons.org/licenses/by-sa/2.5 --> |
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<license/> |
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|
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<version>1.2</version> |
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<date>2008-12-30</date> |
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|
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<chapter> |
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<title>Overview</title> |
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<section> |
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<body> |
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|
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<p> |
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This guide will help you to migrate your existing Gentoo Linux SPARC |
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installation from a non-multilib profile to a multilib profile. |
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</p> |
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|
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<impo> |
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Multilib is still experimental, do not use it if you have to rely on a fully |
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working machine. |
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</impo> |
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|
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<p> |
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Multlib has advantages but it also has some disadvantages, these are the facts: |
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</p> |
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|
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<dl> |
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<dt>Advantages</dt> |
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<dd> |
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<ul> |
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<li>You can compile and run 64 bit binaries</li> |
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<li>Gcc can handle -m32 and -m64 (biarch)</li> |
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<li>One compiler for both kernel and userland</li> |
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</ul> |
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</dd> |
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<dt>Drawbacks</dt> |
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<dd> |
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<ul> |
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<li>Compiling gcc takes twice as long as it did before</li> |
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<li>Compiling glibc takes twice as long as it did before</li> |
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</ul> |
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</dd> |
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</dl> |
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|
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|
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</body> |
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</section> |
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</chapter> |
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|
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<chapter> |
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<title>Preparation</title> |
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<section> |
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<title>Unmask required packages</title> |
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<body> |
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|
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<p> |
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The multilib profile requires recent versions of gcc and glibc, to be |
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exact: |
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</p> |
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|
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<ul> |
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<li><c>>=sys-devel/gcc-4.3.2-r1</c></li> |
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<li><c>>=sys-libs/glibc-2.7</c></li> |
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</ul> |
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|
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<p> |
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Depending on your configuration you may need to add them to |
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<path>/etc/portage/packages.keywords</path> to avoid holdups. |
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</p> |
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|
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</body> |
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</section> |
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|
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<section> |
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<title>Kernel configuration</title> |
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<body> |
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|
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<p> |
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The Linux kernel can be configured to disable 64 bit ELF support and only |
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enable 32 bit ELF support. Make sure your kernel <e>is not</e> configured like |
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that and can acually run 64 bit ELF binaries. |
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</p> |
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|
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<pre caption="Configuration options"> |
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Executable file formats ---> |
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<*> Kernel support for ELF binaries |
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</pre> |
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|
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<p> |
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Which translated to the <path>.config</path> file would be: |
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</p> |
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|
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<pre caption=".config options"> |
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CONFIG_BINFMT_ELF=y |
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</pre> |
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|
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</body> |
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</section> |
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</chapter> |
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|
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<chapter> |
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<title>Migration</title> |
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|
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<section> |
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<title>Update the make.profile symlink</title> |
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<body> |
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|
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<p> |
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Because the profile is still in an experimental state you have to create/change |
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the <path>/etc/make.profile</path> symlink manually. |
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</p> |
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<p> |
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The multilib profile also provides these three sub-profiles for your |
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convenience, just like 2008.0 does: |
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</p> |
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|
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<ul> |
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<li>desktop</li> |
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<li>developer</li> |
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<li>server</li> |
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</ul> |
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|
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<pre caption="Update the make.profile symlink"> |
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$ <i>rm /etc/make.profile</i> |
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|
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$ <i>ln -s /usr/portage/profiles/default/linux/sparc/experimental/multilib /etc/make.profile</i> |
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or |
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$ <i>ln -s /usr/portage/profiles/default/linux/sparc/experimental/multilib/desktop /etc/make.profile</i> |
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or |
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$ <i>ln -s /usr/portage/profiles/default/linux/sparc/experimental/multilib/developer /etc/make.profile</i> |
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or |
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$ <i>ln -s /usr/portage/profiles/default/linux/sparc/experimental/multilib/server /etc/make.profile</i> |
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</pre> |
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|
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</body> |
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</section> |
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|
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<section> |
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<title>Rename lib to lib32</title> |
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<body> |
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|
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<p> |
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Though it is not fully compliant with FHS, common practice in Gentoo is to store |
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32 bit libraries in <e>lib32</e>, 64 bit libraries in <e>lib64</e> and to have |
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<e>lib</e> as a symlink to the default library directory. |
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</p> |
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<p> |
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The 2008.0 profile stores libraries in <e>lib</e>. These commands will rename |
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all <e>lib</e> directories to <e>lib32</e> and create a symlink <e>lib</e> to |
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<e>lib32</e>. Additionally they will create empty <e>lib64</e> directories. |
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</p> |
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|
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<warn> |
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Do not exit your shell while doing this! You would not be able to login again |
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and would have to boot a livecd to recover. |
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</warn> |
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|
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<pre caption="Rename lib to lib32"> |
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$ <i>mv /lib /lib32</i> |
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# sln is a statically linked version of ln |
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$ <i>sln lib32 /lib</i> |
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$ <i>mkdir -p /lib64</i> |
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$ <i>touch /lib64/.keep</i> |
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$ <i>for dir in /usr/qt/*/lib /usr/kde/*/lib /usr/local/lib /usr/lib</i> |
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<i>do</i> |
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<i>if [ -d ${dir} ]</i> |
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<i>then</i> |
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<i>mv ${dir} ${dir}32</i> |
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<i>ln -sf lib32 ${dir}</i> |
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<i>mkdir -p ${dir}64</i> |
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<i>touch ${dir}64/.keep</i> |
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<i>fi</i> |
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<i>done</i> |
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$ <i>ldconfig</i> |
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</pre> |
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|
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</body> |
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</section> |
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|
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<section> |
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<title>Remerge baselayout</title> |
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<body> |
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|
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<p> |
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For multilib profiles, <c>sys-apps/baselayout</c> installs additional files, |
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like <path>/etc/env.d/04multilib</path>. To get these you need to remerge it. |
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</p> |
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|
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<pre caption="Remerge baselayout"> |
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$ <i>emerge --oneshot sys-apps/baselayout</i> |
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$ <i>env-update && source /etc/profile</i> |
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</pre> |
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|
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</body> |
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</section> |
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|
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<section> |
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<title>Install a multilib glibc</title> |
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<body> |
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|
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<p> |
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To compile a multilib glibc you need a biarch gcc but to compile a biarch gcc |
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you need a multilib glibc. You <e>could</e> compile glibc using a |
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cross-compiler such as <c>sys-devel/kgcc64</c> but that is not something you |
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would enjoy... |
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</p> |
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<p> |
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Therefore we will install a binary packages of glibc first and afterwards, |
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once the migration is complete, remerge it with your USE- and CFLAGS. |
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</p> |
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|
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<pre caption="Install binary glibc package"> |
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$ <i>PORTAGE_BINHOST="http://dev.gentoo.org/~bluebird/sparc-multilib/packages" emerge --getbinpkgonly --usepkgonly --oneshot sys-libs/glibc</i> |
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</pre> |
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|
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<p> |
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If you get <e>All ebuilds that could satisfy "sys-libs/glibc" have been |
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masked.</e> try using a different version of glibc, these three are available |
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as binary packages: |
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</p> |
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|
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<ul> |
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<li><c>=sys-libs/glibc-2.7-r2</c></li> |
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<li><c>=sys-libs/glibc-2.8_p20080602-r1</c></li> |
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<li><c>=sys-libs/glibc-2.9_p20081201-r1</c></li> |
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</ul> |
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|
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</body> |
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</section> |
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|
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<section> |
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<title>Install a biarch gcc</title> |
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<body> |
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|
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<p> |
| 294 |
With a multilib glibc installed you can simply compile a biarch gcc using |
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portage. |
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</p> |
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|
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<pre caption="Install biarch gcc"> |
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$ <i>emerge --oneshot sys-devel/gcc</i> |
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</pre> |
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|
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<p> |
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Now you need to configure your system to use the newly installed gcc using |
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gcc-config. Replace <e>4.3.2</e> with the version you just installed. |
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</p> |
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|
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<pre caption="Set native-compiler"> |
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$ <i>gcc-config sparc-unknown-linux-gnu-4.3.2</i> |
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$ <i>source /etc/profile</i> |
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</pre> |
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|
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</body> |
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</section> |
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|
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<section> |
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<title>Remerge glibc with your preferred settings</title> |
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<body> |
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|
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<p> |
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Remerge glibc with your system specific settings(USE-flags, CFLAGS and such). |
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</p> |
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|
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<pre caption="Remerge glibc"> |
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$ <i>emerge --oneshot sys-libs/glibc</i> |
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</pre> |
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|
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<p> |
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If the glibc compilation finishes without any strange error messages it means |
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that your multilib setup is working. You can use <c>file</c> to verify this by |
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checking the contents of <path>/lib64</path>. |
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</p> |
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<pre caption="Verify multilib glibc installation"> |
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$ <i>file /lib64/libc-*.so</i> |
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/lib64/libc-2.7.so: ELF 64-bit MSB shared object, SPARC V9, version 1 (SYSV), for GNU/Linux 2.6.9, stripped |
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</pre> |
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|
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</body> |
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</section> |
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|
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<section> |
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<title>Unmerge kgcc64</title> |
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<body> |
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|
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<p> |
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<c>sys-devel/gcc</c> can compile the kernel now, therefore you don't need |
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<c>sys-devel/kgcc64</c> anymore to do it. If you have some scripts that need |
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it, just replace <e>sparc64-unknown-linux-gnu-gcc</e> with |
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<e>sparc-unknown-linux-gnu-gcc -m64</e>. |
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</p> |
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|
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<pre caption="Unmerge kgcc64"> |
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$ <i>emerge --unmerge sys-devel/kgcc64</i> |
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</pre> |
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|
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</body> |
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</section> |
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|
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<section> |
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<title>Remerge world</title> |
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<body> |
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|
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<note> |
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This step is optional. |
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</note> |
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|
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<p> |
| 367 |
Your system was build with <e>lib</e> as library directory, now it's |
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<e>lib32</e>. Though you will not notice anything because there is a symlink in |
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place but if you have a lot of spare cpu time and like your system clean... |
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</p> |
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<p> |
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Or in other words: If you are one of those guys who uses portage's |
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multilib-strict feature just for the fun of it...this is for you! |
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</p> |
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|
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<pre caption="Remerge world"> |
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$ <i>emerge --emptytree world</i> |
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</pre> |
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|
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</body> |
| 381 |
</section> |
| 382 |
</chapter> |
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<chapter> |
| 384 |
<title>Closing-off</title> |
| 385 |
<section> |
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<title>Usage example</title> |
| 387 |
<body> |
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|
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<p> |
| 390 |
Here's a simple example how to compile a hello world programm in both 32 and |
| 391 |
64 bit. |
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</p> |
| 393 |
|
| 394 |
<pre caption="Sample hello world program, hello_world.c"> |
| 395 |
<ident>#include</ident> <<var>stdio.h</var>> |
| 396 |
<ident>#include</ident> <<var>stdlib.h</var>> |
| 397 |
|
| 398 |
<stmt>int main(int argc, char** argv)</stmt> { |
| 399 |
<keyword>printf</keyword>("<const>hello, world\n</const>"); |
| 400 |
<keyword>return</keyword> <const>EXIT_SUCCESS</const>; |
| 401 |
} |
| 402 |
</pre> |
| 403 |
|
| 404 |
<pre caption="Compile it as 32 bit binary"> |
| 405 |
$ <i>sparc-unknown-linux-gnu-gcc -m32 -o hello_world hello_world.c</i> |
| 406 |
or |
| 407 |
$ <i>sparc-unknown-linux-gnu-gcc -o hello_world hello_world.c</i> |
| 408 |
</pre> |
| 409 |
|
| 410 |
<note> |
| 411 |
If you specify neigther -m32 nor -m64 the compiler will default to -m32. |
| 412 |
</note> |
| 413 |
|
| 414 |
<pre caption="Compile it as 64 bit binary"> |
| 415 |
$ <i>sparc-unknown-linux-gnu-gcc -m64 -o hello_world hello_world.c</i> |
| 416 |
</pre> |
| 417 |
|
| 418 |
</body> |
| 419 |
</section> |
| 420 |
|
| 421 |
<section> |
| 422 |
<title>Things you shouldn't do</title> |
| 423 |
<body> |
| 424 |
|
| 425 |
<p> |
| 426 |
So now you have a multlib installation and you are thinking about adding -m64 |
| 427 |
to CFLAGS in /etc/make.conf and recompiling your entire userland in 64 bit? |
| 428 |
PLEASE DO NOT! |
| 429 |
</p> |
| 430 |
|
| 431 |
<warn> |
| 432 |
<e>Doing this will render your system unusable!</e> Any bugs you report |
| 433 |
will just be closed without any further action. |
| 434 |
</warn> |
| 435 |
|
| 436 |
<p> |
| 437 |
While compiling everything in 64 bit may be a good idea on other 64 bit |
| 438 |
architectures, like AMD64, on SPARC it is not. There are good reasons why we |
| 439 |
have been using a pure 32 bit userland until now, some of these are: |
| 440 |
</p> |
| 441 |
|
| 442 |
<ul> |
| 443 |
<li>32 bit is faster than 64 bit</li> |
| 444 |
<li>32 bit is well tested, 64 bit isn't tested at all</li> |
| 445 |
<li>2039 is still long way off</li> |
| 446 |
</ul> |
| 447 |
|
| 448 |
<p> |
| 449 |
The only reasons why it <e>might</e> be appropriate to compile an application |
| 450 |
in 64 bit are: |
| 451 |
</p> |
| 452 |
|
| 453 |
<ul> |
| 454 |
<li>It needs to access more than 4GB of memory. In the real world this only |
| 455 |
applies to huge databases.</li> |
| 456 |
<li>It needs to talk to the kernel directly. Some applications, like |
| 457 |
<c>net-firewall/iptables</c>, contain ugly hacks to support the 64 bit |
| 458 |
kernel/32 bit userland thing.</li> |
| 459 |
<li>It is a kernel.</li> |
| 460 |
</ul> |
| 461 |
|
| 462 |
<p> |
| 463 |
If you would like to read more about the differences between 32 and 64 bit, |
| 464 |
there are dozens of webpages about it on the internet, one of them is |
| 465 |
<uri>http://www.superlogic.net/downloads/pub/docs/64bit.htm</uri>. |
| 466 |
</p> |
| 467 |
|
| 468 |
</body> |
| 469 |
</section> |
| 470 |
</chapter> |
| 471 |
|
| 472 |
</guide> |
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