| .. _changes: | 
 |  | 
 | Minimal requirements to compile the Kernel | 
 | ++++++++++++++++++++++++++++++++++++++++++ | 
 |  | 
 | Intro | 
 | ===== | 
 |  | 
 | This document is designed to provide a list of the minimum levels of | 
 | software necessary to run the 4.x kernels. | 
 |  | 
 | This document is originally based on my "Changes" file for 2.0.x kernels | 
 | and therefore owes credit to the same people as that file (Jared Mauch, | 
 | Axel Boldt, Alessandro Sigala, and countless other users all over the | 
 | 'net). | 
 |  | 
 | Current Minimal Requirements | 
 | **************************** | 
 |  | 
 | Upgrade to at **least** these software revisions before thinking you've | 
 | encountered a bug!  If you're unsure what version you're currently | 
 | running, the suggested command should tell you. | 
 |  | 
 | Again, keep in mind that this list assumes you are already functionally | 
 | running a Linux kernel.  Also, not all tools are necessary on all | 
 | systems; obviously, if you don't have any PC Card hardware, for example, | 
 | you probably needn't concern yourself with pcmciautils. | 
 |  | 
 | ====================== ===============  ======================================== | 
 |         Program        Minimal version       Command to check the version | 
 | ====================== ===============  ======================================== | 
 | GNU C                  4.9              gcc --version | 
 | Clang/LLVM (optional)  10.0.1           clang --version | 
 | GNU make               3.81             make --version | 
 | binutils               2.23             ld -v | 
 | flex                   2.5.35           flex --version | 
 | bison                  2.0              bison --version | 
 | util-linux             2.10o            fdformat --version | 
 | kmod                   13               depmod -V | 
 | e2fsprogs              1.41.4           e2fsck -V | 
 | jfsutils               1.1.3            fsck.jfs -V | 
 | reiserfsprogs          3.6.3            reiserfsck -V | 
 | xfsprogs               2.6.0            xfs_db -V | 
 | squashfs-tools         4.0              mksquashfs -version | 
 | btrfs-progs            0.18             btrfsck | 
 | pcmciautils            004              pccardctl -V | 
 | quota-tools            3.09             quota -V | 
 | PPP                    2.4.0            pppd --version | 
 | nfs-utils              1.0.5            showmount --version | 
 | procps                 3.2.0            ps --version | 
 | oprofile               0.9              oprofiled --version | 
 | udev                   081              udevd --version | 
 | grub                   0.93             grub --version || grub-install --version | 
 | mcelog                 0.6              mcelog --version | 
 | iptables               1.4.2            iptables -V | 
 | openssl & libcrypto    1.0.0            openssl version | 
 | bc                     1.06.95          bc --version | 
 | Sphinx\ [#f1]_	       1.3		sphinx-build --version | 
 | ====================== ===============  ======================================== | 
 |  | 
 | .. [#f1] Sphinx is needed only to build the Kernel documentation | 
 |  | 
 | Kernel compilation | 
 | ****************** | 
 |  | 
 | GCC | 
 | --- | 
 |  | 
 | The gcc version requirements may vary depending on the type of CPU in your | 
 | computer. | 
 |  | 
 | Clang/LLVM (optional) | 
 | --------------------- | 
 |  | 
 | The latest formal release of clang and LLVM utils (according to | 
 | `releases.llvm.org <https://releases.llvm.org>`_) are supported for building | 
 | kernels. Older releases aren't guaranteed to work, and we may drop workarounds | 
 | from the kernel that were used to support older versions. Please see additional | 
 | docs on :ref:`Building Linux with Clang/LLVM <kbuild_llvm>`. | 
 |  | 
 | Make | 
 | ---- | 
 |  | 
 | You will need GNU make 3.81 or later to build the kernel. | 
 |  | 
 | Binutils | 
 | -------- | 
 |  | 
 | Binutils 2.23 or newer is needed to build the kernel. | 
 |  | 
 | pkg-config | 
 | ---------- | 
 |  | 
 | The build system, as of 4.18, requires pkg-config to check for installed | 
 | kconfig tools and to determine flags settings for use in | 
 | 'make {g,x}config'.  Previously pkg-config was being used but not | 
 | verified or documented. | 
 |  | 
 | Flex | 
 | ---- | 
 |  | 
 | Since Linux 4.16, the build system generates lexical analyzers | 
 | during build.  This requires flex 2.5.35 or later. | 
 |  | 
 |  | 
 | Bison | 
 | ----- | 
 |  | 
 | Since Linux 4.16, the build system generates parsers | 
 | during build.  This requires bison 2.0 or later. | 
 |  | 
 | Perl | 
 | ---- | 
 |  | 
 | You will need perl 5 and the following modules: ``Getopt::Long``, | 
 | ``Getopt::Std``, ``File::Basename``, and ``File::Find`` to build the kernel. | 
 |  | 
 | BC | 
 | -- | 
 |  | 
 | You will need bc to build kernels 3.10 and higher | 
 |  | 
 |  | 
 | OpenSSL | 
 | ------- | 
 |  | 
 | Module signing and external certificate handling use the OpenSSL program and | 
 | crypto library to do key creation and signature generation. | 
 |  | 
 | You will need openssl to build kernels 3.7 and higher if module signing is | 
 | enabled.  You will also need openssl development packages to build kernels 4.3 | 
 | and higher. | 
 |  | 
 |  | 
 | System utilities | 
 | **************** | 
 |  | 
 | Architectural changes | 
 | --------------------- | 
 |  | 
 | DevFS has been obsoleted in favour of udev | 
 | (https://www.kernel.org/pub/linux/utils/kernel/hotplug/) | 
 |  | 
 | 32-bit UID support is now in place.  Have fun! | 
 |  | 
 | Linux documentation for functions is transitioning to inline | 
 | documentation via specially-formatted comments near their | 
 | definitions in the source.  These comments can be combined with ReST | 
 | files the Documentation/ directory to make enriched documentation, which can | 
 | then be converted to PostScript, HTML, LaTex, ePUB and PDF files. | 
 | In order to convert from ReST format to a format of your choice, you'll need | 
 | Sphinx. | 
 |  | 
 | Util-linux | 
 | ---------- | 
 |  | 
 | New versions of util-linux provide ``fdisk`` support for larger disks, | 
 | support new options to mount, recognize more supported partition | 
 | types, have a fdformat which works with 2.4 kernels, and similar goodies. | 
 | You'll probably want to upgrade. | 
 |  | 
 | Ksymoops | 
 | -------- | 
 |  | 
 | If the unthinkable happens and your kernel oopses, you may need the | 
 | ksymoops tool to decode it, but in most cases you don't. | 
 | It is generally preferred to build the kernel with ``CONFIG_KALLSYMS`` so | 
 | that it produces readable dumps that can be used as-is (this also | 
 | produces better output than ksymoops).  If for some reason your kernel | 
 | is not build with ``CONFIG_KALLSYMS`` and you have no way to rebuild and | 
 | reproduce the Oops with that option, then you can still decode that Oops | 
 | with ksymoops. | 
 |  | 
 | Mkinitrd | 
 | -------- | 
 |  | 
 | These changes to the ``/lib/modules`` file tree layout also require that | 
 | mkinitrd be upgraded. | 
 |  | 
 | E2fsprogs | 
 | --------- | 
 |  | 
 | The latest version of ``e2fsprogs`` fixes several bugs in fsck and | 
 | debugfs.  Obviously, it's a good idea to upgrade. | 
 |  | 
 | JFSutils | 
 | -------- | 
 |  | 
 | The ``jfsutils`` package contains the utilities for the file system. | 
 | The following utilities are available: | 
 |  | 
 | - ``fsck.jfs`` - initiate replay of the transaction log, and check | 
 |   and repair a JFS formatted partition. | 
 |  | 
 | - ``mkfs.jfs`` - create a JFS formatted partition. | 
 |  | 
 | - other file system utilities are also available in this package. | 
 |  | 
 | Reiserfsprogs | 
 | ------------- | 
 |  | 
 | The reiserfsprogs package should be used for reiserfs-3.6.x | 
 | (Linux kernels 2.4.x). It is a combined package and contains working | 
 | versions of ``mkreiserfs``, ``resize_reiserfs``, ``debugreiserfs`` and | 
 | ``reiserfsck``. These utils work on both i386 and alpha platforms. | 
 |  | 
 | Xfsprogs | 
 | -------- | 
 |  | 
 | The latest version of ``xfsprogs`` contains ``mkfs.xfs``, ``xfs_db``, and the | 
 | ``xfs_repair`` utilities, among others, for the XFS filesystem.  It is | 
 | architecture independent and any version from 2.0.0 onward should | 
 | work correctly with this version of the XFS kernel code (2.6.0 or | 
 | later is recommended, due to some significant improvements). | 
 |  | 
 | PCMCIAutils | 
 | ----------- | 
 |  | 
 | PCMCIAutils replaces ``pcmcia-cs``. It properly sets up | 
 | PCMCIA sockets at system startup and loads the appropriate modules | 
 | for 16-bit PCMCIA devices if the kernel is modularized and the hotplug | 
 | subsystem is used. | 
 |  | 
 | Quota-tools | 
 | ----------- | 
 |  | 
 | Support for 32 bit uid's and gid's is required if you want to use | 
 | the newer version 2 quota format.  Quota-tools version 3.07 and | 
 | newer has this support.  Use the recommended version or newer | 
 | from the table above. | 
 |  | 
 | Intel IA32 microcode | 
 | -------------------- | 
 |  | 
 | A driver has been added to allow updating of Intel IA32 microcode, | 
 | accessible as a normal (misc) character device.  If you are not using | 
 | udev you may need to:: | 
 |  | 
 |   mkdir /dev/cpu | 
 |   mknod /dev/cpu/microcode c 10 184 | 
 |   chmod 0644 /dev/cpu/microcode | 
 |  | 
 | as root before you can use this.  You'll probably also want to | 
 | get the user-space microcode_ctl utility to use with this. | 
 |  | 
 | udev | 
 | ---- | 
 |  | 
 | ``udev`` is a userspace application for populating ``/dev`` dynamically with | 
 | only entries for devices actually present. ``udev`` replaces the basic | 
 | functionality of devfs, while allowing persistent device naming for | 
 | devices. | 
 |  | 
 | FUSE | 
 | ---- | 
 |  | 
 | Needs libfuse 2.4.0 or later.  Absolute minimum is 2.3.0 but mount | 
 | options ``direct_io`` and ``kernel_cache`` won't work. | 
 |  | 
 | Networking | 
 | ********** | 
 |  | 
 | General changes | 
 | --------------- | 
 |  | 
 | If you have advanced network configuration needs, you should probably | 
 | consider using the network tools from ip-route2. | 
 |  | 
 | Packet Filter / NAT | 
 | ------------------- | 
 | The packet filtering and NAT code uses the same tools like the previous 2.4.x | 
 | kernel series (iptables).  It still includes backwards-compatibility modules | 
 | for 2.2.x-style ipchains and 2.0.x-style ipfwadm. | 
 |  | 
 | PPP | 
 | --- | 
 |  | 
 | The PPP driver has been restructured to support multilink and to | 
 | enable it to operate over diverse media layers.  If you use PPP, | 
 | upgrade pppd to at least 2.4.0. | 
 |  | 
 | If you are not using udev, you must have the device file /dev/ppp | 
 | which can be made by:: | 
 |  | 
 |   mknod /dev/ppp c 108 0 | 
 |  | 
 | as root. | 
 |  | 
 | NFS-utils | 
 | --------- | 
 |  | 
 | In ancient (2.4 and earlier) kernels, the nfs server needed to know | 
 | about any client that expected to be able to access files via NFS.  This | 
 | information would be given to the kernel by ``mountd`` when the client | 
 | mounted the filesystem, or by ``exportfs`` at system startup.  exportfs | 
 | would take information about active clients from ``/var/lib/nfs/rmtab``. | 
 |  | 
 | This approach is quite fragile as it depends on rmtab being correct | 
 | which is not always easy, particularly when trying to implement | 
 | fail-over.  Even when the system is working well, ``rmtab`` suffers from | 
 | getting lots of old entries that never get removed. | 
 |  | 
 | With modern kernels we have the option of having the kernel tell mountd | 
 | when it gets a request from an unknown host, and mountd can give | 
 | appropriate export information to the kernel.  This removes the | 
 | dependency on ``rmtab`` and means that the kernel only needs to know about | 
 | currently active clients. | 
 |  | 
 | To enable this new functionality, you need to:: | 
 |  | 
 |   mount -t nfsd nfsd /proc/fs/nfsd | 
 |  | 
 | before running exportfs or mountd.  It is recommended that all NFS | 
 | services be protected from the internet-at-large by a firewall where | 
 | that is possible. | 
 |  | 
 | mcelog | 
 | ------ | 
 |  | 
 | On x86 kernels the mcelog utility is needed to process and log machine check | 
 | events when ``CONFIG_X86_MCE`` is enabled. Machine check events are errors | 
 | reported by the CPU. Processing them is strongly encouraged. | 
 |  | 
 | Kernel documentation | 
 | ******************** | 
 |  | 
 | Sphinx | 
 | ------ | 
 |  | 
 | Please see :ref:`sphinx_install` in :ref:`Documentation/doc-guide/sphinx.rst <sphinxdoc>` | 
 | for details about Sphinx requirements. | 
 |  | 
 | Getting updated software | 
 | ======================== | 
 |  | 
 | Kernel compilation | 
 | ****************** | 
 |  | 
 | gcc | 
 | --- | 
 |  | 
 | - <ftp://ftp.gnu.org/gnu/gcc/> | 
 |  | 
 | Clang/LLVM | 
 | ---------- | 
 |  | 
 | - :ref:`Getting LLVM <getting_llvm>`. | 
 |  | 
 | Make | 
 | ---- | 
 |  | 
 | - <ftp://ftp.gnu.org/gnu/make/> | 
 |  | 
 | Binutils | 
 | -------- | 
 |  | 
 | - <https://www.kernel.org/pub/linux/devel/binutils/> | 
 |  | 
 | Flex | 
 | ---- | 
 |  | 
 | - <https://github.com/westes/flex/releases> | 
 |  | 
 | Bison | 
 | ----- | 
 |  | 
 | - <ftp://ftp.gnu.org/gnu/bison/> | 
 |  | 
 | OpenSSL | 
 | ------- | 
 |  | 
 | - <https://www.openssl.org/> | 
 |  | 
 | System utilities | 
 | **************** | 
 |  | 
 | Util-linux | 
 | ---------- | 
 |  | 
 | - <https://www.kernel.org/pub/linux/utils/util-linux/> | 
 |  | 
 | Kmod | 
 | ---- | 
 |  | 
 | - <https://www.kernel.org/pub/linux/utils/kernel/kmod/> | 
 | - <https://git.kernel.org/pub/scm/utils/kernel/kmod/kmod.git> | 
 |  | 
 | Ksymoops | 
 | -------- | 
 |  | 
 | - <https://www.kernel.org/pub/linux/utils/kernel/ksymoops/v2.4/> | 
 |  | 
 | Mkinitrd | 
 | -------- | 
 |  | 
 | - <https://code.launchpad.net/initrd-tools/main> | 
 |  | 
 | E2fsprogs | 
 | --------- | 
 |  | 
 | - <https://www.kernel.org/pub/linux/kernel/people/tytso/e2fsprogs/> | 
 | - <https://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git/> | 
 |  | 
 | JFSutils | 
 | -------- | 
 |  | 
 | - <http://jfs.sourceforge.net/> | 
 |  | 
 | Reiserfsprogs | 
 | ------------- | 
 |  | 
 | - <https://git.kernel.org/pub/scm/linux/kernel/git/jeffm/reiserfsprogs.git/> | 
 |  | 
 | Xfsprogs | 
 | -------- | 
 |  | 
 | - <https://git.kernel.org/pub/scm/fs/xfs/xfsprogs-dev.git> | 
 | - <https://www.kernel.org/pub/linux/utils/fs/xfs/xfsprogs/> | 
 |  | 
 | Pcmciautils | 
 | ----------- | 
 |  | 
 | - <https://www.kernel.org/pub/linux/utils/kernel/pcmcia/> | 
 |  | 
 | Quota-tools | 
 | ----------- | 
 |  | 
 | - <http://sourceforge.net/projects/linuxquota/> | 
 |  | 
 |  | 
 | Intel P6 microcode | 
 | ------------------ | 
 |  | 
 | - <https://downloadcenter.intel.com/> | 
 |  | 
 | udev | 
 | ---- | 
 |  | 
 | - <https://www.freedesktop.org/software/systemd/man/udev.html> | 
 |  | 
 | FUSE | 
 | ---- | 
 |  | 
 | - <https://github.com/libfuse/libfuse/releases> | 
 |  | 
 | mcelog | 
 | ------ | 
 |  | 
 | - <http://www.mcelog.org/> | 
 |  | 
 | Networking | 
 | ********** | 
 |  | 
 | PPP | 
 | --- | 
 |  | 
 | - <https://download.samba.org/pub/ppp/> | 
 | - <https://git.ozlabs.org/?p=ppp.git> | 
 | - <https://github.com/paulusmack/ppp/> | 
 |  | 
 | NFS-utils | 
 | --------- | 
 |  | 
 | - <http://sourceforge.net/project/showfiles.php?group_id=14> | 
 |  | 
 | Iptables | 
 | -------- | 
 |  | 
 | - <https://netfilter.org/projects/iptables/index.html> | 
 |  | 
 | Ip-route2 | 
 | --------- | 
 |  | 
 | - <https://www.kernel.org/pub/linux/utils/net/iproute2/> | 
 |  | 
 | OProfile | 
 | -------- | 
 |  | 
 | - <http://oprofile.sf.net/download/> | 
 |  | 
 | NFS-Utils | 
 | --------- | 
 |  | 
 | - <http://nfs.sourceforge.net/> | 
 |  | 
 | Kernel documentation | 
 | ******************** | 
 |  | 
 | Sphinx | 
 | ------ | 
 |  | 
 | - <https://www.sphinx-doc.org/> |