1.. _changes: 2 3Minimal requirements to compile the Kernel 4++++++++++++++++++++++++++++++++++++++++++ 5 6Intro 7===== 8 9This document is designed to provide a list of the minimum levels of 10software necessary to run the current kernel version. 11 12This document is originally based on my "Changes" file for 2.0.x kernels 13and therefore owes credit to the same people as that file (Jared Mauch, 14Axel Boldt, Alessandro Sigala, and countless other users all over the 15'net). 16 17Current Minimal Requirements 18**************************** 19 20Upgrade to at **least** these software revisions before thinking you've 21encountered a bug! If you're unsure what version you're currently 22running, the suggested command should tell you. 23 24Again, keep in mind that this list assumes you are already functionally 25running a Linux kernel. Also, not all tools are necessary on all 26systems; obviously, if you don't have any PC Card hardware, for example, 27you probably needn't concern yourself with pcmciautils. 28 29====================== =============== ======================================== 30 Program Minimal version Command to check the version 31====================== =============== ======================================== 32GNU C 5.1 gcc --version 33Clang/LLVM (optional) 11.0.0 clang --version 34Rust (optional) 1.68.2 rustc --version 35bindgen (optional) 0.56.0 bindgen --version 36GNU make 3.82 make --version 37bash 4.2 bash --version 38binutils 2.25 ld -v 39flex 2.5.35 flex --version 40bison 2.0 bison --version 41pahole 1.16 pahole --version 42util-linux 2.10o fdformat --version 43kmod 13 depmod -V 44e2fsprogs 1.41.4 e2fsck -V 45jfsutils 1.1.3 fsck.jfs -V 46reiserfsprogs 3.6.3 reiserfsck -V 47xfsprogs 2.6.0 xfs_db -V 48squashfs-tools 4.0 mksquashfs -version 49btrfs-progs 0.18 btrfsck 50pcmciautils 004 pccardctl -V 51quota-tools 3.09 quota -V 52PPP 2.4.0 pppd --version 53nfs-utils 1.0.5 showmount --version 54procps 3.2.0 ps --version 55udev 081 udevd --version 56grub 0.93 grub --version || grub-install --version 57mcelog 0.6 mcelog --version 58iptables 1.4.2 iptables -V 59openssl & libcrypto 1.0.0 openssl version 60bc 1.06.95 bc --version 61Sphinx\ [#f1]_ 1.7 sphinx-build --version 62cpio any cpio --version 63====================== =============== ======================================== 64 65.. [#f1] Sphinx is needed only to build the Kernel documentation 66 67Kernel compilation 68****************** 69 70GCC 71--- 72 73The gcc version requirements may vary depending on the type of CPU in your 74computer. 75 76Clang/LLVM (optional) 77--------------------- 78 79The latest formal release of clang and LLVM utils (according to 80`releases.llvm.org <https://releases.llvm.org>`_) are supported for building 81kernels. Older releases aren't guaranteed to work, and we may drop workarounds 82from the kernel that were used to support older versions. Please see additional 83docs on :ref:`Building Linux with Clang/LLVM <kbuild_llvm>`. 84 85Rust (optional) 86--------------- 87 88A particular version of the Rust toolchain is required. Newer versions may or 89may not work because the kernel depends on some unstable Rust features, for 90the moment. 91 92Each Rust toolchain comes with several "components", some of which are required 93(like ``rustc``) and some that are optional. The ``rust-src`` component (which 94is optional) needs to be installed to build the kernel. Other components are 95useful for developing. 96 97Please see Documentation/rust/quick-start.rst for instructions on how to 98satisfy the build requirements of Rust support. In particular, the ``Makefile`` 99target ``rustavailable`` is useful to check why the Rust toolchain may not 100be detected. 101 102bindgen (optional) 103------------------ 104 105``bindgen`` is used to generate the Rust bindings to the C side of the kernel. 106It depends on ``libclang``. 107 108Make 109---- 110 111You will need GNU make 3.82 or later to build the kernel. 112 113Bash 114---- 115 116Some bash scripts are used for the kernel build. 117Bash 4.2 or newer is needed. 118 119Binutils 120-------- 121 122Binutils 2.25 or newer is needed to build the kernel. 123 124pkg-config 125---------- 126 127The build system, as of 4.18, requires pkg-config to check for installed 128kconfig tools and to determine flags settings for use in 129'make {g,x}config'. Previously pkg-config was being used but not 130verified or documented. 131 132Flex 133---- 134 135Since Linux 4.16, the build system generates lexical analyzers 136during build. This requires flex 2.5.35 or later. 137 138 139Bison 140----- 141 142Since Linux 4.16, the build system generates parsers 143during build. This requires bison 2.0 or later. 144 145pahole: 146------- 147 148Since Linux 5.2, if CONFIG_DEBUG_INFO_BTF is selected, the build system 149generates BTF (BPF Type Format) from DWARF in vmlinux, a bit later from kernel 150modules as well. This requires pahole v1.16 or later. 151 152It is found in the 'dwarves' or 'pahole' distro packages or from 153https://fedorapeople.org/~acme/dwarves/. 154 155Perl 156---- 157 158You will need perl 5 and the following modules: ``Getopt::Long``, 159``Getopt::Std``, ``File::Basename``, and ``File::Find`` to build the kernel. 160 161BC 162-- 163 164You will need bc to build kernels 3.10 and higher 165 166 167OpenSSL 168------- 169 170Module signing and external certificate handling use the OpenSSL program and 171crypto library to do key creation and signature generation. 172 173You will need openssl to build kernels 3.7 and higher if module signing is 174enabled. You will also need openssl development packages to build kernels 4.3 175and higher. 176 177 178System utilities 179**************** 180 181Architectural changes 182--------------------- 183 184DevFS has been obsoleted in favour of udev 185(https://www.kernel.org/pub/linux/utils/kernel/hotplug/) 186 18732-bit UID support is now in place. Have fun! 188 189Linux documentation for functions is transitioning to inline 190documentation via specially-formatted comments near their 191definitions in the source. These comments can be combined with ReST 192files the Documentation/ directory to make enriched documentation, which can 193then be converted to PostScript, HTML, LaTex, ePUB and PDF files. 194In order to convert from ReST format to a format of your choice, you'll need 195Sphinx. 196 197Util-linux 198---------- 199 200New versions of util-linux provide ``fdisk`` support for larger disks, 201support new options to mount, recognize more supported partition 202types, have a fdformat which works with 2.4 kernels, and similar goodies. 203You'll probably want to upgrade. 204 205Ksymoops 206-------- 207 208If the unthinkable happens and your kernel oopses, you may need the 209ksymoops tool to decode it, but in most cases you don't. 210It is generally preferred to build the kernel with ``CONFIG_KALLSYMS`` so 211that it produces readable dumps that can be used as-is (this also 212produces better output than ksymoops). If for some reason your kernel 213is not build with ``CONFIG_KALLSYMS`` and you have no way to rebuild and 214reproduce the Oops with that option, then you can still decode that Oops 215with ksymoops. 216 217Mkinitrd 218-------- 219 220These changes to the ``/lib/modules`` file tree layout also require that 221mkinitrd be upgraded. 222 223E2fsprogs 224--------- 225 226The latest version of ``e2fsprogs`` fixes several bugs in fsck and 227debugfs. Obviously, it's a good idea to upgrade. 228 229JFSutils 230-------- 231 232The ``jfsutils`` package contains the utilities for the file system. 233The following utilities are available: 234 235- ``fsck.jfs`` - initiate replay of the transaction log, and check 236 and repair a JFS formatted partition. 237 238- ``mkfs.jfs`` - create a JFS formatted partition. 239 240- other file system utilities are also available in this package. 241 242Reiserfsprogs 243------------- 244 245The reiserfsprogs package should be used for reiserfs-3.6.x 246(Linux kernels 2.4.x). It is a combined package and contains working 247versions of ``mkreiserfs``, ``resize_reiserfs``, ``debugreiserfs`` and 248``reiserfsck``. These utils work on both i386 and alpha platforms. 249 250Xfsprogs 251-------- 252 253The latest version of ``xfsprogs`` contains ``mkfs.xfs``, ``xfs_db``, and the 254``xfs_repair`` utilities, among others, for the XFS filesystem. It is 255architecture independent and any version from 2.0.0 onward should 256work correctly with this version of the XFS kernel code (2.6.0 or 257later is recommended, due to some significant improvements). 258 259PCMCIAutils 260----------- 261 262PCMCIAutils replaces ``pcmcia-cs``. It properly sets up 263PCMCIA sockets at system startup and loads the appropriate modules 264for 16-bit PCMCIA devices if the kernel is modularized and the hotplug 265subsystem is used. 266 267Quota-tools 268----------- 269 270Support for 32 bit uid's and gid's is required if you want to use 271the newer version 2 quota format. Quota-tools version 3.07 and 272newer has this support. Use the recommended version or newer 273from the table above. 274 275Intel IA32 microcode 276-------------------- 277 278A driver has been added to allow updating of Intel IA32 microcode, 279accessible as a normal (misc) character device. If you are not using 280udev you may need to:: 281 282 mkdir /dev/cpu 283 mknod /dev/cpu/microcode c 10 184 284 chmod 0644 /dev/cpu/microcode 285 286as root before you can use this. You'll probably also want to 287get the user-space microcode_ctl utility to use with this. 288 289udev 290---- 291 292``udev`` is a userspace application for populating ``/dev`` dynamically with 293only entries for devices actually present. ``udev`` replaces the basic 294functionality of devfs, while allowing persistent device naming for 295devices. 296 297FUSE 298---- 299 300Needs libfuse 2.4.0 or later. Absolute minimum is 2.3.0 but mount 301options ``direct_io`` and ``kernel_cache`` won't work. 302 303Networking 304********** 305 306General changes 307--------------- 308 309If you have advanced network configuration needs, you should probably 310consider using the network tools from ip-route2. 311 312Packet Filter / NAT 313------------------- 314The packet filtering and NAT code uses the same tools like the previous 2.4.x 315kernel series (iptables). It still includes backwards-compatibility modules 316for 2.2.x-style ipchains and 2.0.x-style ipfwadm. 317 318PPP 319--- 320 321The PPP driver has been restructured to support multilink and to 322enable it to operate over diverse media layers. If you use PPP, 323upgrade pppd to at least 2.4.0. 324 325If you are not using udev, you must have the device file /dev/ppp 326which can be made by:: 327 328 mknod /dev/ppp c 108 0 329 330as root. 331 332NFS-utils 333--------- 334 335In ancient (2.4 and earlier) kernels, the nfs server needed to know 336about any client that expected to be able to access files via NFS. This 337information would be given to the kernel by ``mountd`` when the client 338mounted the filesystem, or by ``exportfs`` at system startup. exportfs 339would take information about active clients from ``/var/lib/nfs/rmtab``. 340 341This approach is quite fragile as it depends on rmtab being correct 342which is not always easy, particularly when trying to implement 343fail-over. Even when the system is working well, ``rmtab`` suffers from 344getting lots of old entries that never get removed. 345 346With modern kernels we have the option of having the kernel tell mountd 347when it gets a request from an unknown host, and mountd can give 348appropriate export information to the kernel. This removes the 349dependency on ``rmtab`` and means that the kernel only needs to know about 350currently active clients. 351 352To enable this new functionality, you need to:: 353 354 mount -t nfsd nfsd /proc/fs/nfsd 355 356before running exportfs or mountd. It is recommended that all NFS 357services be protected from the internet-at-large by a firewall where 358that is possible. 359 360mcelog 361------ 362 363On x86 kernels the mcelog utility is needed to process and log machine check 364events when ``CONFIG_X86_MCE`` is enabled. Machine check events are errors 365reported by the CPU. Processing them is strongly encouraged. 366 367Kernel documentation 368******************** 369 370Sphinx 371------ 372 373Please see :ref:`sphinx_install` in :ref:`Documentation/doc-guide/sphinx.rst <sphinxdoc>` 374for details about Sphinx requirements. 375 376rustdoc 377------- 378 379``rustdoc`` is used to generate the documentation for Rust code. Please see 380Documentation/rust/general-information.rst for more information. 381 382Getting updated software 383======================== 384 385Kernel compilation 386****************** 387 388gcc 389--- 390 391- <ftp://ftp.gnu.org/gnu/gcc/> 392 393Clang/LLVM 394---------- 395 396- :ref:`Getting LLVM <getting_llvm>`. 397 398Rust 399---- 400 401- Documentation/rust/quick-start.rst. 402 403bindgen 404------- 405 406- Documentation/rust/quick-start.rst. 407 408Make 409---- 410 411- <ftp://ftp.gnu.org/gnu/make/> 412 413Bash 414---- 415 416- <ftp://ftp.gnu.org/gnu/bash/> 417 418Binutils 419-------- 420 421- <https://www.kernel.org/pub/linux/devel/binutils/> 422 423Flex 424---- 425 426- <https://github.com/westes/flex/releases> 427 428Bison 429----- 430 431- <ftp://ftp.gnu.org/gnu/bison/> 432 433OpenSSL 434------- 435 436- <https://www.openssl.org/> 437 438System utilities 439**************** 440 441Util-linux 442---------- 443 444- <https://www.kernel.org/pub/linux/utils/util-linux/> 445 446Kmod 447---- 448 449- <https://www.kernel.org/pub/linux/utils/kernel/kmod/> 450- <https://git.kernel.org/pub/scm/utils/kernel/kmod/kmod.git> 451 452Ksymoops 453-------- 454 455- <https://www.kernel.org/pub/linux/utils/kernel/ksymoops/v2.4/> 456 457Mkinitrd 458-------- 459 460- <https://code.launchpad.net/initrd-tools/main> 461 462E2fsprogs 463--------- 464 465- <https://www.kernel.org/pub/linux/kernel/people/tytso/e2fsprogs/> 466- <https://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git/> 467 468JFSutils 469-------- 470 471- <http://jfs.sourceforge.net/> 472 473Reiserfsprogs 474------------- 475 476- <https://git.kernel.org/pub/scm/linux/kernel/git/jeffm/reiserfsprogs.git/> 477 478Xfsprogs 479-------- 480 481- <https://git.kernel.org/pub/scm/fs/xfs/xfsprogs-dev.git> 482- <https://www.kernel.org/pub/linux/utils/fs/xfs/xfsprogs/> 483 484Pcmciautils 485----------- 486 487- <https://www.kernel.org/pub/linux/utils/kernel/pcmcia/> 488 489Quota-tools 490----------- 491 492- <http://sourceforge.net/projects/linuxquota/> 493 494 495Intel P6 microcode 496------------------ 497 498- <https://downloadcenter.intel.com/> 499 500udev 501---- 502 503- <https://www.freedesktop.org/software/systemd/man/udev.html> 504 505FUSE 506---- 507 508- <https://github.com/libfuse/libfuse/releases> 509 510mcelog 511------ 512 513- <http://www.mcelog.org/> 514 515cpio 516---- 517 518- <https://www.gnu.org/software/cpio/> 519 520Networking 521********** 522 523PPP 524--- 525 526- <https://download.samba.org/pub/ppp/> 527- <https://git.ozlabs.org/?p=ppp.git> 528- <https://github.com/paulusmack/ppp/> 529 530NFS-utils 531--------- 532 533- <http://sourceforge.net/project/showfiles.php?group_id=14> 534 535Iptables 536-------- 537 538- <https://netfilter.org/projects/iptables/index.html> 539 540Ip-route2 541--------- 542 543- <https://www.kernel.org/pub/linux/utils/net/iproute2/> 544 545OProfile 546-------- 547 548- <http://oprofile.sf.net/download/> 549 550NFS-Utils 551--------- 552 553- <http://nfs.sourceforge.net/> 554 555Kernel documentation 556******************** 557 558Sphinx 559------ 560 561- <https://www.sphinx-doc.org/> 562