^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) .. _readme:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) Linux kernel release 5.x <http://kernel.org/>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) =============================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) These are the release notes for Linux version 5. Read them carefully,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) as they tell you what this is all about, explain how to install the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) kernel, and what to do if something goes wrong.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) What is Linux?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) --------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) Linux is a clone of the operating system Unix, written from scratch by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) Linus Torvalds with assistance from a loosely-knit team of hackers across
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) the Net. It aims towards POSIX and Single UNIX Specification compliance.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) It has all the features you would expect in a modern fully-fledged Unix,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) including true multitasking, virtual memory, shared libraries, demand
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) loading, shared copy-on-write executables, proper memory management,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) and multistack networking including IPv4 and IPv6.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) It is distributed under the GNU General Public License v2 - see the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) accompanying COPYING file for more details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) On what hardware does it run?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) -----------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) Although originally developed first for 32-bit x86-based PCs (386 or higher),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) today Linux also runs on (at least) the Compaq Alpha AXP, Sun SPARC and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) UltraSPARC, Motorola 68000, PowerPC, PowerPC64, ARM, Hitachi SuperH, Cell,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) IBM S/390, MIPS, HP PA-RISC, Intel IA-64, DEC VAX, AMD x86-64 Xtensa, and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) ARC architectures.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) Linux is easily portable to most general-purpose 32- or 64-bit architectures
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) as long as they have a paged memory management unit (PMMU) and a port of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) GNU C compiler (gcc) (part of The GNU Compiler Collection, GCC). Linux has
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) also been ported to a number of architectures without a PMMU, although
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) functionality is then obviously somewhat limited.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) Linux has also been ported to itself. You can now run the kernel as a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) userspace application - this is called UserMode Linux (UML).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) Documentation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) -------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) - There is a lot of documentation available both in electronic form on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) the Internet and in books, both Linux-specific and pertaining to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) general UNIX questions. I'd recommend looking into the documentation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) subdirectories on any Linux FTP site for the LDP (Linux Documentation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) Project) books. This README is not meant to be documentation on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) system: there are much better sources available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) - There are various README files in the Documentation/ subdirectory:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) these typically contain kernel-specific installation notes for some
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) drivers for example. Please read the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) :ref:`Documentation/process/changes.rst <changes>` file, as it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) contains information about the problems, which may result by upgrading
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) your kernel.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) Installing the kernel source
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) ----------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) - If you install the full sources, put the kernel tarball in a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) directory where you have permissions (e.g. your home directory) and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) unpack it::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) xz -cd linux-5.x.tar.xz | tar xvf -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) Replace "X" with the version number of the latest kernel.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) Do NOT use the /usr/src/linux area! This area has a (usually
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) incomplete) set of kernel headers that are used by the library header
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) files. They should match the library, and not get messed up by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) whatever the kernel-du-jour happens to be.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) - You can also upgrade between 5.x releases by patching. Patches are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) distributed in the xz format. To install by patching, get all the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) newer patch files, enter the top level directory of the kernel source
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) (linux-5.x) and execute::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) xz -cd ../patch-5.x.xz | patch -p1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) Replace "x" for all versions bigger than the version "x" of your current
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) source tree, **in_order**, and you should be ok. You may want to remove
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) the backup files (some-file-name~ or some-file-name.orig), and make sure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) that there are no failed patches (some-file-name# or some-file-name.rej).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) If there are, either you or I have made a mistake.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) Unlike patches for the 5.x kernels, patches for the 5.x.y kernels
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) (also known as the -stable kernels) are not incremental but instead apply
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) directly to the base 5.x kernel. For example, if your base kernel is 5.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) and you want to apply the 5.0.3 patch, you must not first apply the 5.0.1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) and 5.0.2 patches. Similarly, if you are running kernel version 5.0.2 and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) want to jump to 5.0.3, you must first reverse the 5.0.2 patch (that is,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) patch -R) **before** applying the 5.0.3 patch. You can read more on this in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) :ref:`Documentation/process/applying-patches.rst <applying_patches>`.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) Alternatively, the script patch-kernel can be used to automate this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) process. It determines the current kernel version and applies any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) patches found::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) linux/scripts/patch-kernel linux
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) The first argument in the command above is the location of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) kernel source. Patches are applied from the current directory, but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) an alternative directory can be specified as the second argument.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) - Make sure you have no stale .o files and dependencies lying around::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) cd linux
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) make mrproper
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) You should now have the sources correctly installed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) Software requirements
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) ---------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) Compiling and running the 5.x kernels requires up-to-date
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) versions of various software packages. Consult
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) :ref:`Documentation/process/changes.rst <changes>` for the minimum version numbers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) required and how to get updates for these packages. Beware that using
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) excessively old versions of these packages can cause indirect
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) errors that are very difficult to track down, so don't assume that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) you can just update packages when obvious problems arise during
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) build or operation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) Build directory for the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) ------------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) When compiling the kernel, all output files will per default be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) stored together with the kernel source code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) Using the option ``make O=output/dir`` allows you to specify an alternate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) place for the output files (including .config).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) Example::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) kernel source code: /usr/src/linux-5.x
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) build directory: /home/name/build/kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) To configure and build the kernel, use::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) cd /usr/src/linux-5.x
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) make O=/home/name/build/kernel menuconfig
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) make O=/home/name/build/kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) sudo make O=/home/name/build/kernel modules_install install
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) Please note: If the ``O=output/dir`` option is used, then it must be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) used for all invocations of make.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) Configuring the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) ----------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) Do not skip this step even if you are only upgrading one minor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) version. New configuration options are added in each release, and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) odd problems will turn up if the configuration files are not set up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) as expected. If you want to carry your existing configuration to a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) new version with minimal work, use ``make oldconfig``, which will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) only ask you for the answers to new questions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) - Alternative configuration commands are::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) "make config" Plain text interface.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) "make menuconfig" Text based color menus, radiolists & dialogs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) "make nconfig" Enhanced text based color menus.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) "make xconfig" Qt based configuration tool.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) "make gconfig" GTK+ based configuration tool.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) "make oldconfig" Default all questions based on the contents of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) your existing ./.config file and asking about
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) new config symbols.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) "make olddefconfig"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) Like above, but sets new symbols to their default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) values without prompting.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) "make defconfig" Create a ./.config file by using the default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) symbol values from either arch/$ARCH/defconfig
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) or arch/$ARCH/configs/${PLATFORM}_defconfig,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) depending on the architecture.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) "make ${PLATFORM}_defconfig"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) Create a ./.config file by using the default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) symbol values from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) arch/$ARCH/configs/${PLATFORM}_defconfig.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) Use "make help" to get a list of all available
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) platforms of your architecture.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) "make allyesconfig"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) Create a ./.config file by setting symbol
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) values to 'y' as much as possible.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) "make allmodconfig"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) Create a ./.config file by setting symbol
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) values to 'm' as much as possible.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) "make allnoconfig" Create a ./.config file by setting symbol
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) values to 'n' as much as possible.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) "make randconfig" Create a ./.config file by setting symbol
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) values to random values.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) "make localmodconfig" Create a config based on current config and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) loaded modules (lsmod). Disables any module
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) option that is not needed for the loaded modules.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) To create a localmodconfig for another machine,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) store the lsmod of that machine into a file
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) and pass it in as a LSMOD parameter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) Also, you can preserve modules in certain folders
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) or kconfig files by specifying their paths in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) parameter LMC_KEEP.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) target$ lsmod > /tmp/mylsmod
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) target$ scp /tmp/mylsmod host:/tmp
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) host$ make LSMOD=/tmp/mylsmod \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) LMC_KEEP="drivers/usb:drivers/gpu:fs" \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) localmodconfig
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) The above also works when cross compiling.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) "make localyesconfig" Similar to localmodconfig, except it will convert
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) all module options to built in (=y) options. You can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) also preserve modules by LMC_KEEP.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) "make kvmconfig" Enable additional options for kvm guest kernel support.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) "make xenconfig" Enable additional options for xen dom0 guest kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) support.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) "make tinyconfig" Configure the tiniest possible kernel.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) You can find more information on using the Linux kernel config tools
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) in Documentation/kbuild/kconfig.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) - NOTES on ``make config``:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) - Having unnecessary drivers will make the kernel bigger, and can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) under some circumstances lead to problems: probing for a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) nonexistent controller card may confuse your other controllers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) - A kernel with math-emulation compiled in will still use the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) coprocessor if one is present: the math emulation will just
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) never get used in that case. The kernel will be slightly larger,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) but will work on different machines regardless of whether they
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) have a math coprocessor or not.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) - The "kernel hacking" configuration details usually result in a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) bigger or slower kernel (or both), and can even make the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) less stable by configuring some routines to actively try to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) break bad code to find kernel problems (kmalloc()). Thus you
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) should probably answer 'n' to the questions for "development",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) "experimental", or "debugging" features.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) Compiling the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) --------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) - Make sure you have at least gcc 4.9 available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) For more information, refer to :ref:`Documentation/process/changes.rst <changes>`.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) Please note that you can still run a.out user programs with this kernel.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) - Do a ``make`` to create a compressed kernel image. It is also
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) possible to do ``make install`` if you have lilo installed to suit the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) kernel makefiles, but you may want to check your particular lilo setup first.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) To do the actual install, you have to be root, but none of the normal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) build should require that. Don't take the name of root in vain.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) - If you configured any of the parts of the kernel as ``modules``, you
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) will also have to do ``make modules_install``.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) - Verbose kernel compile/build output:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) Normally, the kernel build system runs in a fairly quiet mode (but not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) totally silent). However, sometimes you or other kernel developers need
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) to see compile, link, or other commands exactly as they are executed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) For this, use "verbose" build mode. This is done by passing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) ``V=1`` to the ``make`` command, e.g.::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) make V=1 all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) To have the build system also tell the reason for the rebuild of each
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) target, use ``V=2``. The default is ``V=0``.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) - Keep a backup kernel handy in case something goes wrong. This is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) especially true for the development releases, since each new release
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) contains new code which has not been debugged. Make sure you keep a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) backup of the modules corresponding to that kernel, as well. If you
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) are installing a new kernel with the same version number as your
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) working kernel, make a backup of your modules directory before you
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) do a ``make modules_install``.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) Alternatively, before compiling, use the kernel config option
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) "LOCALVERSION" to append a unique suffix to the regular kernel version.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) LOCALVERSION can be set in the "General Setup" menu.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) - In order to boot your new kernel, you'll need to copy the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) image (e.g. .../linux/arch/x86/boot/bzImage after compilation)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) to the place where your regular bootable kernel is found.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) - Booting a kernel directly from a floppy without the assistance of a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) bootloader such as LILO, is no longer supported.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) If you boot Linux from the hard drive, chances are you use LILO, which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) uses the kernel image as specified in the file /etc/lilo.conf. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) kernel image file is usually /vmlinuz, /boot/vmlinuz, /bzImage or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) /boot/bzImage. To use the new kernel, save a copy of the old image
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) and copy the new image over the old one. Then, you MUST RERUN LILO
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) to update the loading map! If you don't, you won't be able to boot
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) the new kernel image.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) Reinstalling LILO is usually a matter of running /sbin/lilo.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) You may wish to edit /etc/lilo.conf to specify an entry for your
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) old kernel image (say, /vmlinux.old) in case the new one does not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) work. See the LILO docs for more information.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) After reinstalling LILO, you should be all set. Shutdown the system,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) reboot, and enjoy!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) If you ever need to change the default root device, video mode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) etc. in the kernel image, use your bootloader's boot options
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) where appropriate. No need to recompile the kernel to change
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) these parameters.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) - Reboot with the new kernel and enjoy.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) If something goes wrong
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) -----------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) - If you have problems that seem to be due to kernel bugs, please check
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) the file MAINTAINERS to see if there is a particular person associated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) with the part of the kernel that you are having trouble with. If there
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) isn't anyone listed there, then the second best thing is to mail
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) them to me (torvalds@linux-foundation.org), and possibly to any other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) relevant mailing-list or to the newsgroup.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) - In all bug-reports, *please* tell what kernel you are talking about,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) how to duplicate the problem, and what your setup is (use your common
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) sense). If the problem is new, tell me so, and if the problem is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) old, please try to tell me when you first noticed it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) - If the bug results in a message like::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) unable to handle kernel paging request at address C0000010
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) Oops: 0002
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) EIP: 0010:XXXXXXXX
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) eax: xxxxxxxx ebx: xxxxxxxx ecx: xxxxxxxx edx: xxxxxxxx
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) esi: xxxxxxxx edi: xxxxxxxx ebp: xxxxxxxx
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) ds: xxxx es: xxxx fs: xxxx gs: xxxx
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) Pid: xx, process nr: xx
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) xx xx xx xx xx xx xx xx xx xx
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) or similar kernel debugging information on your screen or in your
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) system log, please duplicate it *exactly*. The dump may look
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) incomprehensible to you, but it does contain information that may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) help debugging the problem. The text above the dump is also
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) important: it tells something about why the kernel dumped code (in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) the above example, it's due to a bad kernel pointer). More information
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) on making sense of the dump is in Documentation/admin-guide/bug-hunting.rst
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) - If you compiled the kernel with CONFIG_KALLSYMS you can send the dump
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) as is, otherwise you will have to use the ``ksymoops`` program to make
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) sense of the dump (but compiling with CONFIG_KALLSYMS is usually preferred).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) This utility can be downloaded from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) https://www.kernel.org/pub/linux/utils/kernel/ksymoops/ .
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) Alternatively, you can do the dump lookup by hand:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) - In debugging dumps like the above, it helps enormously if you can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) look up what the EIP value means. The hex value as such doesn't help
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) me or anybody else very much: it will depend on your particular
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) kernel setup. What you should do is take the hex value from the EIP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) line (ignore the ``0010:``), and look it up in the kernel namelist to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) see which kernel function contains the offending address.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) To find out the kernel function name, you'll need to find the system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) binary associated with the kernel that exhibited the symptom. This is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) the file 'linux/vmlinux'. To extract the namelist and match it against
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) the EIP from the kernel crash, do::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) nm vmlinux | sort | less
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) This will give you a list of kernel addresses sorted in ascending
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) order, from which it is simple to find the function that contains the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) offending address. Note that the address given by the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) debugging messages will not necessarily match exactly with the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) function addresses (in fact, that is very unlikely), so you can't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) just 'grep' the list: the list will, however, give you the starting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) point of each kernel function, so by looking for the function that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) has a starting address lower than the one you are searching for but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) is followed by a function with a higher address you will find the one
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) you want. In fact, it may be a good idea to include a bit of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) "context" in your problem report, giving a few lines around the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) interesting one.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) If you for some reason cannot do the above (you have a pre-compiled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) kernel image or similar), telling me as much about your setup as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) possible will help. Please read the :ref:`admin-guide/reporting-bugs.rst <reportingbugs>`
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) document for details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) - Alternatively, you can use gdb on a running kernel. (read-only; i.e. you
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) cannot change values or set break points.) To do this, first compile the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) kernel with -g; edit arch/x86/Makefile appropriately, then do a ``make
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) clean``. You'll also need to enable CONFIG_PROC_FS (via ``make config``).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) After you've rebooted with the new kernel, do ``gdb vmlinux /proc/kcore``.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) You can now use all the usual gdb commands. The command to look up the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) point where your system crashed is ``l *0xXXXXXXXX``. (Replace the XXXes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) with the EIP value.)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) gdb'ing a non-running kernel currently fails because ``gdb`` (wrongly)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) disregards the starting offset for which the kernel is compiled.
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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