1 .. _changes:
2
3 Minimal requirements to compile the Kernel
4 ++++++++++++++++++++++++++++++++++++++++++
5
6 Intro
7 =====
8
9 This document is designed to provide a list of the minimum levels of
10 software necessary to run the current kernel version.
11
12 This document is originally based on my "Changes" file for 2.0.x kernels
13 and therefore owes credit to the same people as that file (Jared Mauch,
14 Axel Boldt, Alessandro Sigala, and countless other users all over the
15 'net).
16
17 Current Minimal Requirements
18 ****************************
19
20 Upgrade to at **least** these software revisions before thinking you've
21 encountered a bug! If you're unsure what version you're currently
22 running, the suggested command should tell you.
23
24 Again, keep in mind that this list assumes you are already functionally
25 running a Linux kernel. Also, not all tools are necessary on all
26 systems; obviously, if you don't have any PC Card hardware, for example,
27 you probably needn't concern yourself with pcmciautils.
28
29 ====================== =============== ========================================
30 Program Minimal version Command to check the version
31 ====================== =============== ========================================
32 GNU C 5.1 gcc --version
33 Clang/LLVM (optional) 13.0.1 clang --version
34 Rust (optional) 1.78.0 rustc --version
35 bindgen (optional) 0.65.1 bindgen --version
36 GNU make 4.0 make --version
37 bash 4.2 bash --version
38 binutils 2.25 ld -v
39 flex 2.5.35 flex --version
40 bison 2.0 bison --version
41 pahole 1.16 pahole --version
42 util-linux 2.10o mount --version
43 kmod 13 depmod -V
44 e2fsprogs 1.41.4 e2fsck -V
45 jfsutils 1.1.3 fsck.jfs -V
46 reiserfsprogs 3.6.3 reiserfsck -V
47 xfsprogs 2.6.0 xfs_db -V
48 squashfs-tools 4.0 mksquashfs -version
49 btrfs-progs 0.18 btrfsck
50 pcmciautils 004 pccardctl -V
51 quota-tools 3.09 quota -V
52 PPP 2.4.0 pppd --version
53 nfs-utils 1.0.5 showmount --version
54 procps 3.2.0 ps --version
55 udev 081 udevd --version
56 grub 0.93 grub --version || grub-install --version
57 mcelog 0.6 mcelog --version
58 iptables 1.4.2 iptables -V
59 openssl & libcrypto 1.0.0 openssl version
60 bc 1.06.95 bc --version
61 Sphinx\ [#f1]_ 2.4.4 sphinx-build --version
62 cpio any cpio --version
63 GNU tar 1.28 tar --version
64 gtags (optional) 6.6.5 gtags --version
65 mkimage (optional) 2017.01 mkimage --version
66 Python (optional) 3.5.x python3 --version
67 GNU AWK (optional) 5.1.0 gawk --version
68 ====================== =============== ========================================
69
70 .. [#f1] Sphinx is needed only to build the Kernel documentation
71
72 Kernel compilation
73 ******************
74
75 GCC
76 ---
77
78 The gcc version requirements may vary depending on the type of CPU in your
79 computer.
80
81 Clang/LLVM (optional)
82 ---------------------
83
84 The latest formal release of clang and LLVM utils (according to
85 `releases.llvm.org <https://releases.llvm.org>`_) are supported for building
86 kernels. Older releases aren't guaranteed to work, and we may drop workarounds
87 from the kernel that were used to support older versions. Please see additional
88 docs on :ref:`Building Linux with Clang/LLVM <kbuild_llvm>`.
89
90 Rust (optional)
91 ---------------
92
93 A recent version of the Rust compiler is required.
94
95 Please see Documentation/rust/quick-start.rst for instructions on how to
96 satisfy the build requirements of Rust support. In particular, the ``Makefile``
97 target ``rustavailable`` is useful to check why the Rust toolchain may not
98 be detected.
99
100 bindgen (optional)
101 ------------------
102
103 ``bindgen`` is used to generate the Rust bindings to the C side of the kernel.
104 It depends on ``libclang``.
105
106 Make
107 ----
108
109 You will need GNU make 4.0 or later to build the kernel.
110
111 Bash
112 ----
113
114 Some bash scripts are used for the kernel build.
115 Bash 4.2 or newer is needed.
116
117 Binutils
118 --------
119
120 Binutils 2.25 or newer is needed to build the kernel.
121
122 pkg-config
123 ----------
124
125 The build system, as of 4.18, requires pkg-config to check for installed
126 kconfig tools and to determine flags settings for use in
127 'make {g,x}config'. Previously pkg-config was being used but not
128 verified or documented.
129
130 Flex
131 ----
132
133 Since Linux 4.16, the build system generates lexical analyzers
134 during build. This requires flex 2.5.35 or later.
135
136
137 Bison
138 -----
139
140 Since Linux 4.16, the build system generates parsers
141 during build. This requires bison 2.0 or later.
142
143 pahole
144 ------
145
146 Since Linux 5.2, if CONFIG_DEBUG_INFO_BTF is selected, the build system
147 generates BTF (BPF Type Format) from DWARF in vmlinux, a bit later from kernel
148 modules as well. This requires pahole v1.16 or later.
149
150 It is found in the 'dwarves' or 'pahole' distro packages or from
151 https://fedorapeople.org/~acme/dwarves/.
152
153 Perl
154 ----
155
156 You will need perl 5 and the following modules: ``Getopt::Long``,
157 ``Getopt::Std``, ``File::Basename``, and ``File::Find`` to build the kernel.
158
159 BC
160 --
161
162 You will need bc to build kernels 3.10 and higher
163
164
165 OpenSSL
166 -------
167
168 Module signing and external certificate handling use the OpenSSL program and
169 crypto library to do key creation and signature generation.
170
171 You will need openssl to build kernels 3.7 and higher if module signing is
172 enabled. You will also need openssl development packages to build kernels 4.3
173 and higher.
174
175 Tar
176 ---
177
178 GNU tar is needed if you want to enable access to the kernel headers via sysfs
179 (CONFIG_IKHEADERS).
180
181 gtags / GNU GLOBAL (optional)
182 -----------------------------
183
184 The kernel build requires GNU GLOBAL version 6.6.5 or later to generate
185 tag files through ``make gtags``. This is due to its use of the gtags
186 ``-C (--directory)`` flag.
187
188 mkimage
189 -------
190
191 This tool is used when building a Flat Image Tree (FIT), commonly used on ARM
192 platforms. The tool is available via the ``u-boot-tools`` package or can be
193 built from the U-Boot source code. See the instructions at
194 https://docs.u-boot.org/en/latest/build/tools.html#building-tools-for-linux
195
196 GNU AWK
197 -------
198
199 GNU AWK is needed if you want kernel builds to generate address range data for
200 builtin modules (CONFIG_BUILTIN_MODULE_RANGES).
201
202 System utilities
203 ****************
204
205 Architectural changes
206 ---------------------
207
208 DevFS has been obsoleted in favour of udev
209 (https://www.kernel.org/pub/linux/utils/kernel/hotplug/)
210
211 32-bit UID support is now in place. Have fun!
212
213 Linux documentation for functions is transitioning to inline
214 documentation via specially-formatted comments near their
215 definitions in the source. These comments can be combined with ReST
216 files the Documentation/ directory to make enriched documentation, which can
217 then be converted to PostScript, HTML, LaTex, ePUB and PDF files.
218 In order to convert from ReST format to a format of your choice, you'll need
219 Sphinx.
220
221 Util-linux
222 ----------
223
224 New versions of util-linux provide ``fdisk`` support for larger disks,
225 support new options to mount, recognize more supported partition
226 types, and similar goodies.
227 You'll probably want to upgrade.
228
229 Ksymoops
230 --------
231
232 If the unthinkable happens and your kernel oopses, you may need the
233 ksymoops tool to decode it, but in most cases you don't.
234 It is generally preferred to build the kernel with ``CONFIG_KALLSYMS`` so
235 that it produces readable dumps that can be used as-is (this also
236 produces better output than ksymoops). If for some reason your kernel
237 is not build with ``CONFIG_KALLSYMS`` and you have no way to rebuild and
238 reproduce the Oops with that option, then you can still decode that Oops
239 with ksymoops.
240
241 Mkinitrd
242 --------
243
244 These changes to the ``/lib/modules`` file tree layout also require that
245 mkinitrd be upgraded.
246
247 E2fsprogs
248 ---------
249
250 The latest version of ``e2fsprogs`` fixes several bugs in fsck and
251 debugfs. Obviously, it's a good idea to upgrade.
252
253 JFSutils
254 --------
255
256 The ``jfsutils`` package contains the utilities for the file system.
257 The following utilities are available:
258
259 - ``fsck.jfs`` - initiate replay of the transaction log, and check
260 and repair a JFS formatted partition.
261
262 - ``mkfs.jfs`` - create a JFS formatted partition.
263
264 - other file system utilities are also available in this package.
265
266 Reiserfsprogs
267 -------------
268
269 The reiserfsprogs package should be used for reiserfs-3.6.x
270 (Linux kernels 2.4.x). It is a combined package and contains working
271 versions of ``mkreiserfs``, ``resize_reiserfs``, ``debugreiserfs`` and
272 ``reiserfsck``. These utils work on both i386 and alpha platforms.
273
274 Xfsprogs
275 --------
276
277 The latest version of ``xfsprogs`` contains ``mkfs.xfs``, ``xfs_db``, and the
278 ``xfs_repair`` utilities, among others, for the XFS filesystem. It is
279 architecture independent and any version from 2.0.0 onward should
280 work correctly with this version of the XFS kernel code (2.6.0 or
281 later is recommended, due to some significant improvements).
282
283 PCMCIAutils
284 -----------
285
286 PCMCIAutils replaces ``pcmcia-cs``. It properly sets up
287 PCMCIA sockets at system startup and loads the appropriate modules
288 for 16-bit PCMCIA devices if the kernel is modularized and the hotplug
289 subsystem is used.
290
291 Quota-tools
292 -----------
293
294 Support for 32 bit uid's and gid's is required if you want to use
295 the newer version 2 quota format. Quota-tools version 3.07 and
296 newer has this support. Use the recommended version or newer
297 from the table above.
298
299 Intel IA32 microcode
300 --------------------
301
302 A driver has been added to allow updating of Intel IA32 microcode,
303 accessible as a normal (misc) character device. If you are not using
304 udev you may need to::
305
306 mkdir /dev/cpu
307 mknod /dev/cpu/microcode c 10 184
308 chmod 0644 /dev/cpu/microcode
309
310 as root before you can use this. You'll probably also want to
311 get the user-space microcode_ctl utility to use with this.
312
313 udev
314 ----
315
316 ``udev`` is a userspace application for populating ``/dev`` dynamically with
317 only entries for devices actually present. ``udev`` replaces the basic
318 functionality of devfs, while allowing persistent device naming for
319 devices.
320
321 FUSE
322 ----
323
324 Needs libfuse 2.4.0 or later. Absolute minimum is 2.3.0 but mount
325 options ``direct_io`` and ``kernel_cache`` won't work.
326
327 Networking
328 **********
329
330 General changes
331 ---------------
332
333 If you have advanced network configuration needs, you should probably
334 consider using the network tools from ip-route2.
335
336 Packet Filter / NAT
337 -------------------
338 The packet filtering and NAT code uses the same tools like the previous 2.4.x
339 kernel series (iptables). It still includes backwards-compatibility modules
340 for 2.2.x-style ipchains and 2.0.x-style ipfwadm.
341
342 PPP
343 ---
344
345 The PPP driver has been restructured to support multilink and to
346 enable it to operate over diverse media layers. If you use PPP,
347 upgrade pppd to at least 2.4.0.
348
349 If you are not using udev, you must have the device file /dev/ppp
350 which can be made by::
351
352 mknod /dev/ppp c 108 0
353
354 as root.
355
356 NFS-utils
357 ---------
358
359 In ancient (2.4 and earlier) kernels, the nfs server needed to know
360 about any client that expected to be able to access files via NFS. This
361 information would be given to the kernel by ``mountd`` when the client
362 mounted the filesystem, or by ``exportfs`` at system startup. exportfs
363 would take information about active clients from ``/var/lib/nfs/rmtab``.
364
365 This approach is quite fragile as it depends on rmtab being correct
366 which is not always easy, particularly when trying to implement
367 fail-over. Even when the system is working well, ``rmtab`` suffers from
368 getting lots of old entries that never get removed.
369
370 With modern kernels we have the option of having the kernel tell mountd
371 when it gets a request from an unknown host, and mountd can give
372 appropriate export information to the kernel. This removes the
373 dependency on ``rmtab`` and means that the kernel only needs to know about
374 currently active clients.
375
376 To enable this new functionality, you need to::
377
378 mount -t nfsd nfsd /proc/fs/nfsd
379
380 before running exportfs or mountd. It is recommended that all NFS
381 services be protected from the internet-at-large by a firewall where
382 that is possible.
383
384 mcelog
385 ------
386
387 On x86 kernels the mcelog utility is needed to process and log machine check
388 events when ``CONFIG_X86_MCE`` is enabled. Machine check events are errors
389 reported by the CPU. Processing them is strongly encouraged.
390
391 Kernel documentation
392 ********************
393
394 Sphinx
395 ------
396
397 Please see :ref:`sphinx_install` in :ref:`Documentation/doc-guide/sphinx.rst <sphinxdoc>`
398 for details about Sphinx requirements.
399
400 rustdoc
401 -------
402
403 ``rustdoc`` is used to generate the documentation for Rust code. Please see
404 Documentation/rust/general-information.rst for more information.
405
406 Getting updated software
407 ========================
408
409 Kernel compilation
410 ******************
411
412 gcc
413 ---
414
415 - <ftp://ftp.gnu.org/gnu/gcc/>
416
417 Clang/LLVM
418 ----------
419
420 - :ref:`Getting LLVM <getting_llvm>`.
421
422 Rust
423 ----
424
425 - Documentation/rust/quick-start.rst.
426
427 bindgen
428 -------
429
430 - Documentation/rust/quick-start.rst.
431
432 Make
433 ----
434
435 - <ftp://ftp.gnu.org/gnu/make/>
436
437 Bash
438 ----
439
440 - <ftp://ftp.gnu.org/gnu/bash/>
441
442 Binutils
443 --------
444
445 - <https://www.kernel.org/pub/linux/devel/binutils/>
446
447 Flex
448 ----
449
450 - <https://github.com/westes/flex/releases>
451
452 Bison
453 -----
454
455 - <ftp://ftp.gnu.org/gnu/bison/>
456
457 OpenSSL
458 -------
459
460 - <https://www.openssl.org/>
461
462 System utilities
463 ****************
464
465 Util-linux
466 ----------
467
468 - <https://www.kernel.org/pub/linux/utils/util-linux/>
469
470 Kmod
471 ----
472
473 - <https://www.kernel.org/pub/linux/utils/kernel/kmod/>
474 - <https://git.kernel.org/pub/scm/utils/kernel/kmod/kmod.git>
475
476 Ksymoops
477 --------
478
479 - <https://www.kernel.org/pub/linux/utils/kernel/ksymoops/v2.4/>
480
481 Mkinitrd
482 --------
483
484 - <https://code.launchpad.net/initrd-tools/main>
485
486 E2fsprogs
487 ---------
488
489 - <https://www.kernel.org/pub/linux/kernel/people/tytso/e2fsprogs/>
490 - <https://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git/>
491
492 JFSutils
493 --------
494
495 - <https://jfs.sourceforge.net/>
496
497 Reiserfsprogs
498 -------------
499
500 - <https://git.kernel.org/pub/scm/linux/kernel/git/jeffm/reiserfsprogs.git/>
501
502 Xfsprogs
503 --------
504
505 - <https://git.kernel.org/pub/scm/fs/xfs/xfsprogs-dev.git>
506 - <https://www.kernel.org/pub/linux/utils/fs/xfs/xfsprogs/>
507
508 Pcmciautils
509 -----------
510
511 - <https://www.kernel.org/pub/linux/utils/kernel/pcmcia/>
512
513 Quota-tools
514 -----------
515
516 - <https://sourceforge.net/projects/linuxquota/>
517
518
519 Intel P6 microcode
520 ------------------
521
522 - <https://downloadcenter.intel.com/>
523
524 udev
525 ----
526
527 - <https://www.freedesktop.org/software/systemd/man/udev.html>
528
529 FUSE
530 ----
531
532 - <https://github.com/libfuse/libfuse/releases>
533
534 mcelog
535 ------
536
537 - <https://www.mcelog.org/>
538
539 cpio
540 ----
541
542 - <https://www.gnu.org/software/cpio/>
543
544 Networking
545 **********
546
547 PPP
548 ---
549
550 - <https://download.samba.org/pub/ppp/>
551 - <https://git.ozlabs.org/?p=ppp.git>
552 - <https://github.com/paulusmack/ppp/>
553
554 NFS-utils
555 ---------
556
557 - <https://sourceforge.net/project/showfiles.php?group_id=14>
558 - <https://nfs.sourceforge.net/>
559
560 Iptables
561 --------
562
563 - <https://netfilter.org/projects/iptables/index.html>
564
565 Ip-route2
566 ---------
567
568 - <https://www.kernel.org/pub/linux/utils/net/iproute2/>
569
570 OProfile
571 --------
572
573 - <https://oprofile.sf.net/download/>
574
575 Kernel documentation
576 ********************
577
578 Sphinx
579 ------
580
581 - <https://www.sphinx-doc.org/>
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