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