Loading...
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) 13.0.1 clang --version
34Rust (optional) 1.78.0 rustc --version
35bindgen (optional) 0.65.1 bindgen --version
36GNU make 4.0 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 mount --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 btrfs --version
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]_ 2.4.4 sphinx-build --version
62cpio any cpio --version
63GNU tar 1.28 tar --version
64gtags (optional) 6.6.5 gtags --version
65mkimage (optional) 2017.01 mkimage --version
66Python (optional) 3.5.x python3 --version
67GNU AWK (optional) 5.1.0 gawk --version
68====================== =============== ========================================
69
70.. [#f1] Sphinx is needed only to build the Kernel documentation
71
72Kernel compilation
73******************
74
75GCC
76---
77
78The gcc version requirements may vary depending on the type of CPU in your
79computer.
80
81Clang/LLVM (optional)
82---------------------
83
84The latest formal release of clang and LLVM utils (according to
85`releases.llvm.org <https://releases.llvm.org>`_) are supported for building
86kernels. Older releases aren't guaranteed to work, and we may drop workarounds
87from the kernel that were used to support older versions. Please see additional
88docs on :ref:`Building Linux with Clang/LLVM <kbuild_llvm>`.
89
90Rust (optional)
91---------------
92
93A recent version of the Rust compiler is required.
94
95Please see Documentation/rust/quick-start.rst for instructions on how to
96satisfy the build requirements of Rust support. In particular, the ``Makefile``
97target ``rustavailable`` is useful to check why the Rust toolchain may not
98be detected.
99
100bindgen (optional)
101------------------
102
103``bindgen`` is used to generate the Rust bindings to the C side of the kernel.
104It depends on ``libclang``.
105
106Make
107----
108
109You will need GNU make 4.0 or later to build the kernel.
110
111Bash
112----
113
114Some bash scripts are used for the kernel build.
115Bash 4.2 or newer is needed.
116
117Binutils
118--------
119
120Binutils 2.25 or newer is needed to build the kernel.
121
122pkg-config
123----------
124
125The build system, as of 4.18, requires pkg-config to check for installed
126kconfig tools and to determine flags settings for use in
127'make {g,x}config'. Previously pkg-config was being used but not
128verified or documented.
129
130Flex
131----
132
133Since Linux 4.16, the build system generates lexical analyzers
134during build. This requires flex 2.5.35 or later.
135
136
137Bison
138-----
139
140Since Linux 4.16, the build system generates parsers
141during build. This requires bison 2.0 or later.
142
143pahole
144------
145
146Since Linux 5.2, if CONFIG_DEBUG_INFO_BTF is selected, the build system
147generates BTF (BPF Type Format) from DWARF in vmlinux, a bit later from kernel
148modules as well. This requires pahole v1.16 or later.
149
150It is found in the 'dwarves' or 'pahole' distro packages or from
151https://fedorapeople.org/~acme/dwarves/.
152
153Perl
154----
155
156You will need perl 5 and the following modules: ``Getopt::Long``,
157``Getopt::Std``, ``File::Basename``, and ``File::Find`` to build the kernel.
158
159BC
160--
161
162You will need bc to build kernels 3.10 and higher
163
164
165OpenSSL
166-------
167
168Module signing and external certificate handling use the OpenSSL program and
169crypto library to do key creation and signature generation.
170
171You will need openssl to build kernels 3.7 and higher if module signing is
172enabled. You will also need openssl development packages to build kernels 4.3
173and higher.
174
175Tar
176---
177
178GNU tar is needed if you want to enable access to the kernel headers via sysfs
179(CONFIG_IKHEADERS).
180
181gtags / GNU GLOBAL (optional)
182-----------------------------
183
184The kernel build requires GNU GLOBAL version 6.6.5 or later to generate
185tag files through ``make gtags``. This is due to its use of the gtags
186``-C (--directory)`` flag.
187
188mkimage
189-------
190
191This tool is used when building a Flat Image Tree (FIT), commonly used on ARM
192platforms. The tool is available via the ``u-boot-tools`` package or can be
193built from the U-Boot source code. See the instructions at
194https://docs.u-boot.org/en/latest/build/tools.html#building-tools-for-linux
195
196GNU AWK
197-------
198
199GNU AWK is needed if you want kernel builds to generate address range data for
200builtin modules (CONFIG_BUILTIN_MODULE_RANGES).
201
202System utilities
203****************
204
205Architectural changes
206---------------------
207
208DevFS has been obsoleted in favour of udev
209(https://www.kernel.org/pub/linux/utils/kernel/hotplug/)
210
21132-bit UID support is now in place. Have fun!
212
213Linux documentation for functions is transitioning to inline
214documentation via specially-formatted comments near their
215definitions in the source. These comments can be combined with ReST
216files the Documentation/ directory to make enriched documentation, which can
217then be converted to PostScript, HTML, LaTex, ePUB and PDF files.
218In order to convert from ReST format to a format of your choice, you'll need
219Sphinx.
220
221Util-linux
222----------
223
224New versions of util-linux provide ``fdisk`` support for larger disks,
225support new options to mount, recognize more supported partition
226types, and similar goodies.
227You'll probably want to upgrade.
228
229Ksymoops
230--------
231
232If the unthinkable happens and your kernel oopses, you may need the
233ksymoops tool to decode it, but in most cases you don't.
234It is generally preferred to build the kernel with ``CONFIG_KALLSYMS`` so
235that it produces readable dumps that can be used as-is (this also
236produces better output than ksymoops). If for some reason your kernel
237is not build with ``CONFIG_KALLSYMS`` and you have no way to rebuild and
238reproduce the Oops with that option, then you can still decode that Oops
239with ksymoops.
240
241Mkinitrd
242--------
243
244These changes to the ``/lib/modules`` file tree layout also require that
245mkinitrd be upgraded.
246
247E2fsprogs
248---------
249
250The latest version of ``e2fsprogs`` fixes several bugs in fsck and
251debugfs. Obviously, it's a good idea to upgrade.
252
253JFSutils
254--------
255
256The ``jfsutils`` package contains the utilities for the file system.
257The 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
266Reiserfsprogs
267-------------
268
269The reiserfsprogs package should be used for reiserfs-3.6.x
270(Linux kernels 2.4.x). It is a combined package and contains working
271versions of ``mkreiserfs``, ``resize_reiserfs``, ``debugreiserfs`` and
272``reiserfsck``. These utils work on both i386 and alpha platforms.
273
274Xfsprogs
275--------
276
277The latest version of ``xfsprogs`` contains ``mkfs.xfs``, ``xfs_db``, and the
278``xfs_repair`` utilities, among others, for the XFS filesystem. It is
279architecture independent and any version from 2.0.0 onward should
280work correctly with this version of the XFS kernel code (2.6.0 or
281later is recommended, due to some significant improvements).
282
283PCMCIAutils
284-----------
285
286PCMCIAutils replaces ``pcmcia-cs``. It properly sets up
287PCMCIA sockets at system startup and loads the appropriate modules
288for 16-bit PCMCIA devices if the kernel is modularized and the hotplug
289subsystem is used.
290
291Quota-tools
292-----------
293
294Support for 32 bit uid's and gid's is required if you want to use
295the newer version 2 quota format. Quota-tools version 3.07 and
296newer has this support. Use the recommended version or newer
297from the table above.
298
299Intel IA32 microcode
300--------------------
301
302A driver has been added to allow updating of Intel IA32 microcode,
303accessible as a normal (misc) character device. If you are not using
304udev you may need to::
305
306 mkdir /dev/cpu
307 mknod /dev/cpu/microcode c 10 184
308 chmod 0644 /dev/cpu/microcode
309
310as root before you can use this. You'll probably also want to
311get the user-space microcode_ctl utility to use with this.
312
313udev
314----
315
316``udev`` is a userspace application for populating ``/dev`` dynamically with
317only entries for devices actually present. ``udev`` replaces the basic
318functionality of devfs, while allowing persistent device naming for
319devices.
320
321FUSE
322----
323
324Needs libfuse 2.4.0 or later. Absolute minimum is 2.3.0 but mount
325options ``direct_io`` and ``kernel_cache`` won't work.
326
327Networking
328**********
329
330General changes
331---------------
332
333If you have advanced network configuration needs, you should probably
334consider using the network tools from ip-route2.
335
336Packet Filter / NAT
337-------------------
338The packet filtering and NAT code uses the same tools like the previous 2.4.x
339kernel series (iptables). It still includes backwards-compatibility modules
340for 2.2.x-style ipchains and 2.0.x-style ipfwadm.
341
342PPP
343---
344
345The PPP driver has been restructured to support multilink and to
346enable it to operate over diverse media layers. If you use PPP,
347upgrade pppd to at least 2.4.0.
348
349If you are not using udev, you must have the device file /dev/ppp
350which can be made by::
351
352 mknod /dev/ppp c 108 0
353
354as root.
355
356NFS-utils
357---------
358
359In ancient (2.4 and earlier) kernels, the nfs server needed to know
360about any client that expected to be able to access files via NFS. This
361information would be given to the kernel by ``mountd`` when the client
362mounted the filesystem, or by ``exportfs`` at system startup. exportfs
363would take information about active clients from ``/var/lib/nfs/rmtab``.
364
365This approach is quite fragile as it depends on rmtab being correct
366which is not always easy, particularly when trying to implement
367fail-over. Even when the system is working well, ``rmtab`` suffers from
368getting lots of old entries that never get removed.
369
370With modern kernels we have the option of having the kernel tell mountd
371when it gets a request from an unknown host, and mountd can give
372appropriate export information to the kernel. This removes the
373dependency on ``rmtab`` and means that the kernel only needs to know about
374currently active clients.
375
376To enable this new functionality, you need to::
377
378 mount -t nfsd nfsd /proc/fs/nfsd
379
380before running exportfs or mountd. It is recommended that all NFS
381services be protected from the internet-at-large by a firewall where
382that is possible.
383
384mcelog
385------
386
387On x86 kernels the mcelog utility is needed to process and log machine check
388events when ``CONFIG_X86_MCE`` is enabled. Machine check events are errors
389reported by the CPU. Processing them is strongly encouraged.
390
391Kernel documentation
392********************
393
394Sphinx
395------
396
397Please see :ref:`sphinx_install` in :ref:`Documentation/doc-guide/sphinx.rst <sphinxdoc>`
398for details about Sphinx requirements.
399
400rustdoc
401-------
402
403``rustdoc`` is used to generate the documentation for Rust code. Please see
404Documentation/rust/general-information.rst for more information.
405
406Getting updated software
407========================
408
409Kernel compilation
410******************
411
412gcc
413---
414
415- <ftp://ftp.gnu.org/gnu/gcc/>
416
417Clang/LLVM
418----------
419
420- :ref:`Getting LLVM <getting_llvm>`.
421
422Rust
423----
424
425- Documentation/rust/quick-start.rst.
426
427bindgen
428-------
429
430- Documentation/rust/quick-start.rst.
431
432Make
433----
434
435- <ftp://ftp.gnu.org/gnu/make/>
436
437Bash
438----
439
440- <ftp://ftp.gnu.org/gnu/bash/>
441
442Binutils
443--------
444
445- <https://www.kernel.org/pub/linux/devel/binutils/>
446
447Flex
448----
449
450- <https://github.com/westes/flex/releases>
451
452Bison
453-----
454
455- <ftp://ftp.gnu.org/gnu/bison/>
456
457OpenSSL
458-------
459
460- <https://www.openssl.org/>
461
462System utilities
463****************
464
465Util-linux
466----------
467
468- <https://www.kernel.org/pub/linux/utils/util-linux/>
469
470Kmod
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
476Ksymoops
477--------
478
479- <https://www.kernel.org/pub/linux/utils/kernel/ksymoops/v2.4/>
480
481Mkinitrd
482--------
483
484- <https://code.launchpad.net/initrd-tools/main>
485
486E2fsprogs
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
492JFSutils
493--------
494
495- <https://jfs.sourceforge.net/>
496
497Reiserfsprogs
498-------------
499
500- <https://git.kernel.org/pub/scm/linux/kernel/git/jeffm/reiserfsprogs.git/>
501
502Xfsprogs
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
508Pcmciautils
509-----------
510
511- <https://www.kernel.org/pub/linux/utils/kernel/pcmcia/>
512
513Quota-tools
514-----------
515
516- <https://sourceforge.net/projects/linuxquota/>
517
518
519Intel P6 microcode
520------------------
521
522- <https://downloadcenter.intel.com/>
523
524udev
525----
526
527- <https://www.freedesktop.org/software/systemd/man/udev.html>
528
529FUSE
530----
531
532- <https://github.com/libfuse/libfuse/releases>
533
534mcelog
535------
536
537- <https://www.mcelog.org/>
538
539cpio
540----
541
542- <https://www.gnu.org/software/cpio/>
543
544Networking
545**********
546
547PPP
548---
549
550- <https://download.samba.org/pub/ppp/>
551- <https://git.ozlabs.org/?p=ppp.git>
552- <https://github.com/paulusmack/ppp/>
553
554NFS-utils
555---------
556
557- <https://sourceforge.net/project/showfiles.php?group_id=14>
558- <https://nfs.sourceforge.net/>
559
560Iptables
561--------
562
563- <https://netfilter.org/projects/iptables/index.html>
564
565Ip-route2
566---------
567
568- <https://www.kernel.org/pub/linux/utils/net/iproute2/>
569
570OProfile
571--------
572
573- <https://oprofile.sf.net/download/>
574
575Kernel documentation
576********************
577
578Sphinx
579------
580
581- <https://www.sphinx-doc.org/>
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) 13.0.1 clang --version
34Rust (optional) 1.76.0 rustc --version
35bindgen (optional) 0.65.1 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 mount --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]_ 2.4.4 sphinx-build --version
62cpio any cpio --version
63GNU tar 1.28 tar --version
64gtags (optional) 6.6.5 gtags --version
65====================== =============== ========================================
66
67.. [#f1] Sphinx is needed only to build the Kernel documentation
68
69Kernel compilation
70******************
71
72GCC
73---
74
75The gcc version requirements may vary depending on the type of CPU in your
76computer.
77
78Clang/LLVM (optional)
79---------------------
80
81The latest formal release of clang and LLVM utils (according to
82`releases.llvm.org <https://releases.llvm.org>`_) are supported for building
83kernels. Older releases aren't guaranteed to work, and we may drop workarounds
84from the kernel that were used to support older versions. Please see additional
85docs on :ref:`Building Linux with Clang/LLVM <kbuild_llvm>`.
86
87Rust (optional)
88---------------
89
90A particular version of the Rust toolchain is required. Newer versions may or
91may not work because the kernel depends on some unstable Rust features, for
92the moment.
93
94Each Rust toolchain comes with several "components", some of which are required
95(like ``rustc``) and some that are optional. The ``rust-src`` component (which
96is optional) needs to be installed to build the kernel. Other components are
97useful for developing.
98
99Please see Documentation/rust/quick-start.rst for instructions on how to
100satisfy the build requirements of Rust support. In particular, the ``Makefile``
101target ``rustavailable`` is useful to check why the Rust toolchain may not
102be detected.
103
104bindgen (optional)
105------------------
106
107``bindgen`` is used to generate the Rust bindings to the C side of the kernel.
108It depends on ``libclang``.
109
110Make
111----
112
113You will need GNU make 3.82 or later to build the kernel.
114
115Bash
116----
117
118Some bash scripts are used for the kernel build.
119Bash 4.2 or newer is needed.
120
121Binutils
122--------
123
124Binutils 2.25 or newer is needed to build the kernel.
125
126pkg-config
127----------
128
129The build system, as of 4.18, requires pkg-config to check for installed
130kconfig tools and to determine flags settings for use in
131'make {g,x}config'. Previously pkg-config was being used but not
132verified or documented.
133
134Flex
135----
136
137Since Linux 4.16, the build system generates lexical analyzers
138during build. This requires flex 2.5.35 or later.
139
140
141Bison
142-----
143
144Since Linux 4.16, the build system generates parsers
145during build. This requires bison 2.0 or later.
146
147pahole
148------
149
150Since Linux 5.2, if CONFIG_DEBUG_INFO_BTF is selected, the build system
151generates BTF (BPF Type Format) from DWARF in vmlinux, a bit later from kernel
152modules as well. This requires pahole v1.16 or later.
153
154It is found in the 'dwarves' or 'pahole' distro packages or from
155https://fedorapeople.org/~acme/dwarves/.
156
157Perl
158----
159
160You will need perl 5 and the following modules: ``Getopt::Long``,
161``Getopt::Std``, ``File::Basename``, and ``File::Find`` to build the kernel.
162
163BC
164--
165
166You will need bc to build kernels 3.10 and higher
167
168
169OpenSSL
170-------
171
172Module signing and external certificate handling use the OpenSSL program and
173crypto library to do key creation and signature generation.
174
175You will need openssl to build kernels 3.7 and higher if module signing is
176enabled. You will also need openssl development packages to build kernels 4.3
177and higher.
178
179Tar
180---
181
182GNU tar is needed if you want to enable access to the kernel headers via sysfs
183(CONFIG_IKHEADERS).
184
185gtags / GNU GLOBAL (optional)
186-----------------------------
187
188The kernel build requires GNU GLOBAL version 6.6.5 or later to generate
189tag files through ``make gtags``. This is due to its use of the gtags
190``-C (--directory)`` flag.
191
192System utilities
193****************
194
195Architectural changes
196---------------------
197
198DevFS has been obsoleted in favour of udev
199(https://www.kernel.org/pub/linux/utils/kernel/hotplug/)
200
20132-bit UID support is now in place. Have fun!
202
203Linux documentation for functions is transitioning to inline
204documentation via specially-formatted comments near their
205definitions in the source. These comments can be combined with ReST
206files the Documentation/ directory to make enriched documentation, which can
207then be converted to PostScript, HTML, LaTex, ePUB and PDF files.
208In order to convert from ReST format to a format of your choice, you'll need
209Sphinx.
210
211Util-linux
212----------
213
214New versions of util-linux provide ``fdisk`` support for larger disks,
215support new options to mount, recognize more supported partition
216types, and similar goodies.
217You'll probably want to upgrade.
218
219Ksymoops
220--------
221
222If the unthinkable happens and your kernel oopses, you may need the
223ksymoops tool to decode it, but in most cases you don't.
224It is generally preferred to build the kernel with ``CONFIG_KALLSYMS`` so
225that it produces readable dumps that can be used as-is (this also
226produces better output than ksymoops). If for some reason your kernel
227is not build with ``CONFIG_KALLSYMS`` and you have no way to rebuild and
228reproduce the Oops with that option, then you can still decode that Oops
229with ksymoops.
230
231Mkinitrd
232--------
233
234These changes to the ``/lib/modules`` file tree layout also require that
235mkinitrd be upgraded.
236
237E2fsprogs
238---------
239
240The latest version of ``e2fsprogs`` fixes several bugs in fsck and
241debugfs. Obviously, it's a good idea to upgrade.
242
243JFSutils
244--------
245
246The ``jfsutils`` package contains the utilities for the file system.
247The following utilities are available:
248
249- ``fsck.jfs`` - initiate replay of the transaction log, and check
250 and repair a JFS formatted partition.
251
252- ``mkfs.jfs`` - create a JFS formatted partition.
253
254- other file system utilities are also available in this package.
255
256Reiserfsprogs
257-------------
258
259The reiserfsprogs package should be used for reiserfs-3.6.x
260(Linux kernels 2.4.x). It is a combined package and contains working
261versions of ``mkreiserfs``, ``resize_reiserfs``, ``debugreiserfs`` and
262``reiserfsck``. These utils work on both i386 and alpha platforms.
263
264Xfsprogs
265--------
266
267The latest version of ``xfsprogs`` contains ``mkfs.xfs``, ``xfs_db``, and the
268``xfs_repair`` utilities, among others, for the XFS filesystem. It is
269architecture independent and any version from 2.0.0 onward should
270work correctly with this version of the XFS kernel code (2.6.0 or
271later is recommended, due to some significant improvements).
272
273PCMCIAutils
274-----------
275
276PCMCIAutils replaces ``pcmcia-cs``. It properly sets up
277PCMCIA sockets at system startup and loads the appropriate modules
278for 16-bit PCMCIA devices if the kernel is modularized and the hotplug
279subsystem is used.
280
281Quota-tools
282-----------
283
284Support for 32 bit uid's and gid's is required if you want to use
285the newer version 2 quota format. Quota-tools version 3.07 and
286newer has this support. Use the recommended version or newer
287from the table above.
288
289Intel IA32 microcode
290--------------------
291
292A driver has been added to allow updating of Intel IA32 microcode,
293accessible as a normal (misc) character device. If you are not using
294udev you may need to::
295
296 mkdir /dev/cpu
297 mknod /dev/cpu/microcode c 10 184
298 chmod 0644 /dev/cpu/microcode
299
300as root before you can use this. You'll probably also want to
301get the user-space microcode_ctl utility to use with this.
302
303udev
304----
305
306``udev`` is a userspace application for populating ``/dev`` dynamically with
307only entries for devices actually present. ``udev`` replaces the basic
308functionality of devfs, while allowing persistent device naming for
309devices.
310
311FUSE
312----
313
314Needs libfuse 2.4.0 or later. Absolute minimum is 2.3.0 but mount
315options ``direct_io`` and ``kernel_cache`` won't work.
316
317Networking
318**********
319
320General changes
321---------------
322
323If you have advanced network configuration needs, you should probably
324consider using the network tools from ip-route2.
325
326Packet Filter / NAT
327-------------------
328The packet filtering and NAT code uses the same tools like the previous 2.4.x
329kernel series (iptables). It still includes backwards-compatibility modules
330for 2.2.x-style ipchains and 2.0.x-style ipfwadm.
331
332PPP
333---
334
335The PPP driver has been restructured to support multilink and to
336enable it to operate over diverse media layers. If you use PPP,
337upgrade pppd to at least 2.4.0.
338
339If you are not using udev, you must have the device file /dev/ppp
340which can be made by::
341
342 mknod /dev/ppp c 108 0
343
344as root.
345
346NFS-utils
347---------
348
349In ancient (2.4 and earlier) kernels, the nfs server needed to know
350about any client that expected to be able to access files via NFS. This
351information would be given to the kernel by ``mountd`` when the client
352mounted the filesystem, or by ``exportfs`` at system startup. exportfs
353would take information about active clients from ``/var/lib/nfs/rmtab``.
354
355This approach is quite fragile as it depends on rmtab being correct
356which is not always easy, particularly when trying to implement
357fail-over. Even when the system is working well, ``rmtab`` suffers from
358getting lots of old entries that never get removed.
359
360With modern kernels we have the option of having the kernel tell mountd
361when it gets a request from an unknown host, and mountd can give
362appropriate export information to the kernel. This removes the
363dependency on ``rmtab`` and means that the kernel only needs to know about
364currently active clients.
365
366To enable this new functionality, you need to::
367
368 mount -t nfsd nfsd /proc/fs/nfsd
369
370before running exportfs or mountd. It is recommended that all NFS
371services be protected from the internet-at-large by a firewall where
372that is possible.
373
374mcelog
375------
376
377On x86 kernels the mcelog utility is needed to process and log machine check
378events when ``CONFIG_X86_MCE`` is enabled. Machine check events are errors
379reported by the CPU. Processing them is strongly encouraged.
380
381Kernel documentation
382********************
383
384Sphinx
385------
386
387Please see :ref:`sphinx_install` in :ref:`Documentation/doc-guide/sphinx.rst <sphinxdoc>`
388for details about Sphinx requirements.
389
390rustdoc
391-------
392
393``rustdoc`` is used to generate the documentation for Rust code. Please see
394Documentation/rust/general-information.rst for more information.
395
396Getting updated software
397========================
398
399Kernel compilation
400******************
401
402gcc
403---
404
405- <ftp://ftp.gnu.org/gnu/gcc/>
406
407Clang/LLVM
408----------
409
410- :ref:`Getting LLVM <getting_llvm>`.
411
412Rust
413----
414
415- Documentation/rust/quick-start.rst.
416
417bindgen
418-------
419
420- Documentation/rust/quick-start.rst.
421
422Make
423----
424
425- <ftp://ftp.gnu.org/gnu/make/>
426
427Bash
428----
429
430- <ftp://ftp.gnu.org/gnu/bash/>
431
432Binutils
433--------
434
435- <https://www.kernel.org/pub/linux/devel/binutils/>
436
437Flex
438----
439
440- <https://github.com/westes/flex/releases>
441
442Bison
443-----
444
445- <ftp://ftp.gnu.org/gnu/bison/>
446
447OpenSSL
448-------
449
450- <https://www.openssl.org/>
451
452System utilities
453****************
454
455Util-linux
456----------
457
458- <https://www.kernel.org/pub/linux/utils/util-linux/>
459
460Kmod
461----
462
463- <https://www.kernel.org/pub/linux/utils/kernel/kmod/>
464- <https://git.kernel.org/pub/scm/utils/kernel/kmod/kmod.git>
465
466Ksymoops
467--------
468
469- <https://www.kernel.org/pub/linux/utils/kernel/ksymoops/v2.4/>
470
471Mkinitrd
472--------
473
474- <https://code.launchpad.net/initrd-tools/main>
475
476E2fsprogs
477---------
478
479- <https://www.kernel.org/pub/linux/kernel/people/tytso/e2fsprogs/>
480- <https://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git/>
481
482JFSutils
483--------
484
485- <https://jfs.sourceforge.net/>
486
487Reiserfsprogs
488-------------
489
490- <https://git.kernel.org/pub/scm/linux/kernel/git/jeffm/reiserfsprogs.git/>
491
492Xfsprogs
493--------
494
495- <https://git.kernel.org/pub/scm/fs/xfs/xfsprogs-dev.git>
496- <https://www.kernel.org/pub/linux/utils/fs/xfs/xfsprogs/>
497
498Pcmciautils
499-----------
500
501- <https://www.kernel.org/pub/linux/utils/kernel/pcmcia/>
502
503Quota-tools
504-----------
505
506- <https://sourceforge.net/projects/linuxquota/>
507
508
509Intel P6 microcode
510------------------
511
512- <https://downloadcenter.intel.com/>
513
514udev
515----
516
517- <https://www.freedesktop.org/software/systemd/man/udev.html>
518
519FUSE
520----
521
522- <https://github.com/libfuse/libfuse/releases>
523
524mcelog
525------
526
527- <https://www.mcelog.org/>
528
529cpio
530----
531
532- <https://www.gnu.org/software/cpio/>
533
534Networking
535**********
536
537PPP
538---
539
540- <https://download.samba.org/pub/ppp/>
541- <https://git.ozlabs.org/?p=ppp.git>
542- <https://github.com/paulusmack/ppp/>
543
544NFS-utils
545---------
546
547- <https://sourceforge.net/project/showfiles.php?group_id=14>
548- <https://nfs.sourceforge.net/>
549
550Iptables
551--------
552
553- <https://netfilter.org/projects/iptables/index.html>
554
555Ip-route2
556---------
557
558- <https://www.kernel.org/pub/linux/utils/net/iproute2/>
559
560OProfile
561--------
562
563- <https://oprofile.sf.net/download/>
564
565Kernel documentation
566********************
567
568Sphinx
569------
570
571- <https://www.sphinx-doc.org/>