OpenCloudOS-Kernel/Documentation/admin-guide
Linus Torvalds 9388076b4c ACPI updates for 6.1-rc1
- Reimplement acpi_get_pci_dev() using the list of physical devices
    associated with the given ACPI device object (Rafael Wysocki).
 
  - Rename ACPI device object reference counting functions (Rafael
    Wysocki).
 
  - Rearrange ACPI device object initialization code (Rafael Wysocki).
 
  - Drop parent field from struct acpi_device (Rafael Wysocki).
 
  - Extend the the int3472-tps68470 driver to support multiple consumers
    of a single TPS68470 along with the requisite framework-level
    support (Daniel Scally).
 
  - Filter out non-memory resources in is_memory(), add a helper
    function to find all memory type resources of an ACPI device object
    and use that function in 3 places (Heikki Krogerus).
 
  - Add IRQ override quirks for Asus Vivobook K3402ZA/K3502ZA and ASUS
    model S5402ZA (Tamim Khan, Kellen Renshaw).
 
  - Fix acpi_dev_state_d0() kerneldoc (Sakari Ailus).
 
  - Fix up suspend-to-idle support on ASUS Rembrandt laptops (Mario
    Limonciello).
 
  - Clean up ACPI platform devices support code (Andy Shevchenko, John
    Garry).
 
  - Clean up ACPI bus management code (Andy Shevchenko, ye xingchen).
 
  - Add support for multiple DMA windows with different offsets to the
    ACPI device enumeration code and use it on LoongArch (Jianmin Lv).
 
  - Clean up the ACPI LPSS (Intel SoC) driver (Andy Shevchenko).
 
  - Add a quirk for Dell Inspiron 14 2-in-1 for StorageD3Enable (Mario
    Limonciello).
 
  - Drop unused dev_fmt() and redundant 'HMAT' prefix from the HMAT
    parsing code (Liu Shixin).
 
  - Make ACPI FPDT parsing code avoid calling acpi_os_map_memory() on
    invalid physical addresses (Hans de Goede).
 
  - Silence missing-declarations warning related to Apple device
    properties management (Lukas Wunner).
 
  - Disable frequency invariance in the CPPC library if registers used
    by cppc_get_perf_ctrs() are accessed via PCC (Jeremy Linton).
 
  - Add ACPI disabled check to acpi_cpc_valid() (Perry Yuan).
 
  - Fix Tx acknowledge in the PCC address space handler (Huisong Li).
 
  - Use wait_for_completion_timeout() for PCC mailbox operations (Huisong
    Li).
 
  - Release resources on PCC address space setup failure path (Rafael
    Mendonca).
 
  - Remove unneeded result variables from APEI code (ye xingchen).
 
  - Print total number of records found during BERT log parsing (Dmitry
    Monakhov).
 
  - Drop support for 3 _OSI strings that should not be necessary any
    more and update documentation on custom _OSI strings so that adding
    new ones is not encouraged any more (Mario Limonciello).
 
  - Drop unneeded result variable from ec_write() (ye xingchen).
 
  - Remove the leftover struct acpi_ac_bl from the ACPI AC driver (Hanjun
    Guo).
 
  - Reorder symbols to get rid of a few forward declarations in the ACPI
    fan driver (Uwe Kleine-König).
 
  - Add Toshiba Satellite/Portege Z830 ACPI backlight quirk (Arvid
    Norlander).
 
  - Add ARM DMA-330 controller to the supported list in the ACPI AMBA
    driver (Vijayenthiran Subramaniam).
 
  - Drop references to non-functional 01.org/linux-acpi web site from
    MAINTAINERS and Kconfig help texts (Rafael Wysocki).
 
  - Replace strlcpy() with unused retval with strscpy() in the ACPI
    support code (Wolfram Sang).
 
  - Do not initialize ret in main() in the pfrut utility (Shi junming).
 
  - Drop useless ACPI DSDT override documentation (Rafael Wysocki).
 
  - Fix a few typos and wording mistakes in the ACPI device enumeration
    documentation (Jean Delvare).
 
  - Introduce acpi_dev_uid_to_integer() to convert a _UID string into an
    integer value (Andy Shevchenko).
 
  - Use acpi_dev_uid_to_integer() in several places to unify _UID
    handling (Andy Shevchenko).
 
  - Drop unused pnpid32_to_pnpid() declaration from  PNP code (Gaosheng
    Cui).
 -----BEGIN PGP SIGNATURE-----
 
 iQJGBAABCAAwFiEE4fcc61cGeeHD/fCwgsRv/nhiVHEFAmM7OhkSHHJqd0Byand5
 c29ja2kubmV0AAoJEILEb/54YlRx/TkQALQ4TN451dPSj9jcYSNY6qZ/9b4P9Iym
 TmRf3wO3+IVZQ8JajeKKRuVKNsW3sC0RcFkJJVmgZkydJBr1Uui2L0ZLzi8axGNy
 RlbZm5NyBeFnlP0fA8Gb2iRMXVAUcRIx+RvZCulxxFmgQ8UhoU4wlVZWlEcko4TQ
 hGp++lJYcRHR1NbVLSXZhFvzopKLdhGL6vB1Awsjb/I7TVqn23+k4jVRV1DYkIQ7
 qgFM+Z7osRVZiVQbaPoOgdykeSa43qXu7Vgs7F/QeJuIiUYx59xDh0/WCJBxnuDM
 cHGiaNnvuJghKmCg43X8+joaHEH/jCFyvBVGfiSzRvjz03WOPRs1XztwdEiCi+py
 RcZGzrPaXmkCjNeytPRooiifyqm95HT7aMBN/aTvKBXDaGRrfPheXF+i2idl24HM
 NrHqMaa0+5qoDGHLUEaf5znlCHfS+3lwq6+lGVrq/UGf6B3cP+9HwOyevEW493JX
 4nuv69Y517moR9W3mBU8sAn5mUjshcka7pghRj7QnuoqRqWLbU3lIz8oUDHr84cI
 ixpIPvt2KlZ5UjnN9aqu/6k70JkJvy4SrKjnx4iqu03ePmMrRc0Hcpy7+VMlgumD
 tgN9aW+YDgy0/Z5QmO1MOvFodVmA5sX6+gnX1neAjuDdIo3LkJptlkO1fCx2jfQu
 cgPQk1CtPOos
 =xyUK
 -----END PGP SIGNATURE-----

Merge tag 'acpi-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI updates from Rafael Wysocki:
 "ACPI and PNP updates for 6.1-rc1.

  These rearrange the ACPI device object initialization code (to get rid
  of a redundant parent pointer from struct acpi_device among other
  things), unify the _UID handling, drop support for some _OSI strings
  that should not be necessary any more, add new IDs to support more
  hardware and some more quirks, fix a few issues and clean up code all
  over.

  Specifics:

   - Reimplement acpi_get_pci_dev() using the list of physical devices
     associated with the given ACPI device object (Rafael Wysocki)

   - Rename ACPI device object reference counting functions (Rafael
     Wysocki)

   - Rearrange ACPI device object initialization code (Rafael Wysocki)

   - Drop parent field from struct acpi_device (Rafael Wysocki)

   - Extend the the int3472-tps68470 driver to support multiple
     consumers of a single TPS68470 along with the requisite
     framework-level support (Daniel Scally)

   - Filter out non-memory resources in is_memory(), add a helper
     function to find all memory type resources of an ACPI device object
     and use that function in 3 places (Heikki Krogerus)

   - Add IRQ override quirks for Asus Vivobook K3402ZA/K3502ZA and ASUS
     model S5402ZA (Tamim Khan, Kellen Renshaw)

   - Fix acpi_dev_state_d0() kerneldoc (Sakari Ailus)

   - Fix up suspend-to-idle support on ASUS Rembrandt laptops (Mario
     Limonciello)

   - Clean up ACPI platform devices support code (Andy Shevchenko, John
     Garry)

   - Clean up ACPI bus management code (Andy Shevchenko, ye xingchen)

   - Add support for multiple DMA windows with different offsets to the
     ACPI device enumeration code and use it on LoongArch (Jianmin Lv)

   - Clean up the ACPI LPSS (Intel SoC) driver (Andy Shevchenko)

   - Add a quirk for Dell Inspiron 14 2-in-1 for StorageD3Enable (Mario
     Limonciello)

   - Drop unused dev_fmt() and redundant 'HMAT' prefix from the HMAT
     parsing code (Liu Shixin)

   - Make ACPI FPDT parsing code avoid calling acpi_os_map_memory() on
     invalid physical addresses (Hans de Goede)

   - Silence missing-declarations warning related to Apple device
     properties management (Lukas Wunner)

   - Disable frequency invariance in the CPPC library if registers used
     by cppc_get_perf_ctrs() are accessed via PCC (Jeremy Linton)

   - Add ACPI disabled check to acpi_cpc_valid() (Perry Yuan)

   - Fix Tx acknowledge in the PCC address space handler (Huisong Li)

   - Use wait_for_completion_timeout() for PCC mailbox operations
     (Huisong Li)

   - Release resources on PCC address space setup failure path (Rafael
     Mendonca)

   - Remove unneeded result variables from APEI code (ye xingchen)

   - Print total number of records found during BERT log parsing (Dmitry
     Monakhov)

   - Drop support for 3 _OSI strings that should not be necessary any
     more and update documentation on custom _OSI strings so that adding
     new ones is not encouraged any more (Mario Limonciello)

   - Drop unneeded result variable from ec_write() (ye xingchen)

   - Remove the leftover struct acpi_ac_bl from the ACPI AC driver
     (Hanjun Guo)

   - Reorder symbols to get rid of a few forward declarations in the
     ACPI fan driver (Uwe Kleine-König)

   - Add Toshiba Satellite/Portege Z830 ACPI backlight quirk (Arvid
     Norlander)

   - Add ARM DMA-330 controller to the supported list in the ACPI AMBA
     driver (Vijayenthiran Subramaniam)

   - Drop references to non-functional 01.org/linux-acpi web site from
     MAINTAINERS and Kconfig help texts (Rafael Wysocki)

   - Replace strlcpy() with unused retval with strscpy() in the ACPI
     support code (Wolfram Sang)

   - Do not initialize ret in main() in the pfrut utility (Shi junming)

   - Drop useless ACPI DSDT override documentation (Rafael Wysocki)

   - Fix a few typos and wording mistakes in the ACPI device enumeration
     documentation (Jean Delvare)

   - Introduce acpi_dev_uid_to_integer() to convert a _UID string into
     an integer value (Andy Shevchenko)

   - Use acpi_dev_uid_to_integer() in several places to unify _UID
     handling (Andy Shevchenko)

   - Drop unused pnpid32_to_pnpid() declaration from PNP code (Gaosheng
     Cui)"

* tag 'acpi-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (79 commits)
  ACPI: LPSS: Deduplicate skipping device in acpi_lpss_create_device()
  ACPI: LPSS: Replace loop with first entry retrieval
  ACPI: x86: s2idle: Add another ID to s2idle_dmi_table
  ACPI: x86: s2idle: Fix a NULL pointer dereference
  MAINTAINERS: Drop records pointing to 01.org/linux-acpi
  ACPI: Kconfig: Drop link to https://01.org/linux-acpi
  ACPI: docs: Drop useless DSDT override documentation
  ACPI: DPTF: Drop stale link from Kconfig help
  ACPI: x86: s2idle: Add a quirk for ASUSTeK COMPUTER INC. ROG Flow X13
  ACPI: x86: s2idle: Add a quirk for Lenovo Slim 7 Pro 14ARH7
  ACPI: x86: s2idle: Add a quirk for ASUS ROG Zephyrus G14
  ACPI: x86: s2idle: Add a quirk for ASUS TUF Gaming A17 FA707RE
  ACPI: x86: s2idle: Add module parameter to prefer Microsoft GUID
  ACPI: x86: s2idle: If a new AMD _HID is missing assume Rembrandt
  ACPI: x86: s2idle: Move _HID handling for AMD systems into structures
  platform/x86: int3472: Add board data for Surface Go2 IR camera
  platform/x86: int3472: Support multiple gpio lookups in board data
  platform/x86: int3472: Support multiple clock consumers
  ACPI: bus: Add iterator for dependent devices
  ACPI: scan: Add acpi_dev_get_next_consumer_dev()
  ...
2022-10-03 13:19:53 -07:00
..
LSM security/loadpin: Update the changing interface in the source code. 2021-03-15 13:32:32 -06:00
acpi ACPI: docs: Drop useless DSDT override documentation 2022-09-28 17:31:23 +02:00
aoe
auxdisplay treewide: Miguel has moved 2021-02-26 09:41:03 -08:00
blockdev A handful of late-arriving documentation fixes and the addition of an SVG 2022-06-02 15:36:06 -07:00
cgroup-v1 filemap: Remove add_to_page_cache() and add_to_page_cache_locked() 2022-06-29 08:51:05 -04:00
cifs Documentation, arch: Remove leftovers from CIFS_WEAK_PW_HASH 2021-12-17 14:12:03 +01:00
device-mapper dm writecache: count number of blocks discarded, not number of discard bios 2022-07-14 15:54:46 -04:00
gpio gpio: sim: add doc file to index file 2022-01-24 09:21:28 +01:00
hw-vuln There's not a huge amount of activity in the docs tree this time around, 2022-10-03 10:23:32 -07:00
kdump Remove duplicate words inside documentation 2022-09-27 13:21:43 -06:00
laptops lg-laptop: Move setting of battery charge limit to common location 2022-02-23 11:36:24 +01:00
media media: vimc: documentation for lens 2022-07-15 14:44:51 +01:00
mm There's not a huge amount of activity in the docs tree this time around, 2022-10-03 10:23:32 -07:00
namespaces
nfs NFS: update documentation for the nfs4_unique_id parameter 2022-05-17 15:30:03 -04:00
perf docs: perf: Include hns3-pmu.rst in toctree to fix 'htmldocs' WARNING 2022-07-07 11:25:40 +01:00
pm - Remove the vendor check when selecting MWAIT as the default idle state 2022-08-01 09:49:29 -07:00
sysctl net: Fix data-races around netdev_max_backlog. 2022-08-24 13:46:57 +01:00
README.rst There's not a huge amount of activity in the docs tree this time around, 2022-10-03 10:23:32 -07:00
abi-obsolete.rst docs: ABI: don't escape ReST-incompatible chars from obsolete and removed 2020-10-30 13:07:02 +01:00
abi-removed.rst docs: ABI: don't escape ReST-incompatible chars from obsolete and removed 2020-10-30 13:07:02 +01:00
abi-stable.rst docs: ABI: make it parse ABI/stable as ReST-compatible files 2020-10-30 13:07:02 +01:00
abi-testing.rst docs: abi-testing.rst: enable --rst-sources when building docs 2020-10-30 13:07:02 +01:00
abi.rst docs: ABI: create a 2-depth index for ABI 2020-10-30 13:07:02 +01:00
bcache.rst
binderfs.rst docs: binderfs: add section about feature files 2021-07-21 13:46:36 +02:00
binfmt-misc.rst docs: binfmt-misc: Fix .rst formatting 2021-01-07 14:43:03 -07:00
bootconfig.rst docs: bootconfig: Add how to embed the bootconfig into kernel 2022-04-26 17:58:51 -04:00
braille-console.rst
btmrvl.rst
bug-bisect.rst docs: make reporting-bugs.rst obsolete 2020-12-08 10:33:27 -07:00
bug-hunting.rst Documentation: fix typos found in admin-guide subdirectory 2020-12-08 10:25:42 -07:00
cgroup-v2.rst - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
clearing-warn-once.rst
cpu-load.rst Documentation: Replace lkml.org links with lore 2021-01-11 12:47:38 -07:00
cputopology.rst topology/sysfs: get rid of htmldoc warning 2021-12-07 11:20:45 +01:00
dell_rbu.rst
devices.rst docs: admin: devices: drop confusing outdated statement on Latex 2022-07-14 15:03:56 -06:00
devices.txt net: wan: remove support for COSA and SRP synchronous serial boards 2022-04-27 12:22:56 +01:00
dynamic-debug-howto.rst dyndbg: refine verbosity 1-4 summary-detail 2021-10-21 13:01:25 +02:00
edid.rst
efi-stub.rst docs: efi-stub: Fix paths for x86 / arm stubs 2022-07-28 09:41:56 -06:00
ext4.rst docs: fix a cross-ref 2021-06-13 17:02:46 -06:00
features.rst docs: admin-guide: add a features list 2020-12-03 15:10:15 -07:00
filesystem-monitoring.rst docs: Fix formatting of literal sections in fanotify docs 2021-11-01 12:45:06 +01:00
highuid.rst
hw_random.rst
index.rst docs: add two documents about regression handling 2022-02-24 12:57:25 -07:00
init.rst
initrd.rst
iostats.rst Documentation: block/diskstats: update function names 2022-02-24 12:18:54 -07:00
java.rst
jfs.rst
kernel-parameters.rst Docs/admin: alphabetize some kernel-parameters (part 1) 2022-04-16 02:49:05 -06:00
kernel-parameters.txt arm64: fix rodata=full 2022-08-23 11:02:02 +01:00
kernel-per-CPU-kthreads.rst doc: Remove obsolete kernel-per-CPU-kthreads RCU_FAST_NO_HZ advice 2021-11-30 17:23:06 -08:00
lcd-panel-cgram.rst
ldm.rst
lockup-watchdogs.rst doc: watchdog: modify the explanation related to watchdog thread 2021-06-29 10:53:46 -07:00
md.rst Documentation: fix multiple typos found in the admin-guide subdirectory 2020-12-08 10:27:56 -07:00
module-signing.rst Documentation: fix multiple typos found in the admin-guide subdirectory 2020-12-08 10:27:56 -07:00
mono.rst
numastat.rst
parport.rst
perf-security.rst doc/admin-guide: fix spelling mistake: "perfomance" -> "performance" 2021-02-11 09:38:40 -07:00
pnp.rst PNP: remove the now unused pnp_find_card() function 2020-10-08 18:00:08 +02:00
pstore-blk.rst pstore/blk: Fix kerndoc and redundancy on blkdev param 2021-06-16 09:27:32 -07:00
ramoops.rst dt-bindings: reserved-memory: ramoops: update ramoops.yaml references 2021-10-19 11:54:16 -05:00
rapidio.rst
ras.rst
reporting-issues.rst docs: reporting-issues.rst: link new document about regressions 2022-02-24 12:57:25 -07:00
reporting-regressions.rst docs: *-regressions.rst: explain how quickly issues should be handled 2022-02-24 12:57:25 -07:00
rtc.rst
security-bugs.rst docs: make reporting-bugs.rst obsolete 2020-12-08 10:33:27 -07:00
serial-console.rst
spkguide.txt speakup: Fix typo in documentation "boo" -> "boot" 2021-11-01 11:17:21 -06:00
svga.rst Documentation/admin-guide: README & svga: remove use of "rdev" 2020-09-24 10:50:31 -06:00
syscall-user-dispatch.rst entry: Use different define for selector variable in SUD 2021-02-06 00:21:42 +01:00
sysfs-rules.rst
sysrq.rst Documentation: sysrq: convert to third person 2021-07-15 06:33:44 -06:00
tainted-kernels.rst panic: Taint kernel if tests are run 2022-07-01 16:38:35 -06:00
thunderbolt.rst thunderbolt: Add support for retimer NVM upgrade when there is no link 2021-06-01 10:53:31 +03:00
ufs.rst
unicode.rst
vga-softcursor.rst
video-output.rst
xfs.rst xfs: rename the blockgc workqueue 2021-03-25 16:47:50 -07:00

README.rst

.. _readme:

Linux kernel release 6.x <http://kernel.org/>
=============================================

These are the release notes for Linux version 6.  Read them carefully,
as they tell you what this is all about, explain how to install the
kernel, and what to do if something goes wrong.

What is Linux?
--------------

  Linux is a clone of the operating system Unix, written from scratch by
  Linus Torvalds with assistance from a loosely-knit team of hackers across
  the Net. It aims towards POSIX and Single UNIX Specification compliance.

  It has all the features you would expect in a modern fully-fledged Unix,
  including true multitasking, virtual memory, shared libraries, demand
  loading, shared copy-on-write executables, proper memory management,
  and multistack networking including IPv4 and IPv6.

  It is distributed under the GNU General Public License v2 - see the
  accompanying COPYING file for more details.

On what hardware does it run?
-----------------------------

  Although originally developed first for 32-bit x86-based PCs (386 or higher),
  today Linux also runs on (at least) the Compaq Alpha AXP, Sun SPARC and
  UltraSPARC, Motorola 68000, PowerPC, PowerPC64, ARM, Hitachi SuperH, Cell,
  IBM S/390, MIPS, HP PA-RISC, Intel IA-64, DEC VAX, AMD x86-64 Xtensa, and
  ARC architectures.

  Linux is easily portable to most general-purpose 32- or 64-bit architectures
  as long as they have a paged memory management unit (PMMU) and a port of the
  GNU C compiler (gcc) (part of The GNU Compiler Collection, GCC). Linux has
  also been ported to a number of architectures without a PMMU, although
  functionality is then obviously somewhat limited.
  Linux has also been ported to itself. You can now run the kernel as a
  userspace application - this is called UserMode Linux (UML).

Documentation
-------------

 - There is a lot of documentation available both in electronic form on
   the Internet and in books, both Linux-specific and pertaining to
   general UNIX questions.  I'd recommend looking into the documentation
   subdirectories on any Linux FTP site for the LDP (Linux Documentation
   Project) books.  This README is not meant to be documentation on the
   system: there are much better sources available.

 - There are various README files in the Documentation/ subdirectory:
   these typically contain kernel-specific installation notes for some
   drivers for example. Please read the
   :ref:`Documentation/process/changes.rst <changes>` file, as it
   contains information about the problems, which may result by upgrading
   your kernel.

Installing the kernel source
----------------------------

 - If you install the full sources, put the kernel tarball in a
   directory where you have permissions (e.g. your home directory) and
   unpack it::

     xz -cd linux-6.x.tar.xz | tar xvf -

   Replace "X" with the version number of the latest kernel.

   Do NOT use the /usr/src/linux area! This area has a (usually
   incomplete) set of kernel headers that are used by the library header
   files.  They should match the library, and not get messed up by
   whatever the kernel-du-jour happens to be.

 - You can also upgrade between 6.x releases by patching.  Patches are
   distributed in the xz format.  To install by patching, get all the
   newer patch files, enter the top level directory of the kernel source
   (linux-6.x) and execute::

     xz -cd ../patch-6.x.xz | patch -p1

   Replace "x" for all versions bigger than the version "x" of your current
   source tree, **in_order**, and you should be ok.  You may want to remove
   the backup files (some-file-name~ or some-file-name.orig), and make sure
   that there are no failed patches (some-file-name# or some-file-name.rej).
   If there are, either you or I have made a mistake.

   Unlike patches for the 6.x kernels, patches for the 6.x.y kernels
   (also known as the -stable kernels) are not incremental but instead apply
   directly to the base 6.x kernel.  For example, if your base kernel is 6.0
   and you want to apply the 6.0.3 patch, you must not first apply the 6.0.1
   and 6.0.2 patches. Similarly, if you are running kernel version 6.0.2 and
   want to jump to 6.0.3, you must first reverse the 6.0.2 patch (that is,
   patch -R) **before** applying the 6.0.3 patch. You can read more on this in
   :ref:`Documentation/process/applying-patches.rst <applying_patches>`.

   Alternatively, the script patch-kernel can be used to automate this
   process.  It determines the current kernel version and applies any
   patches found::

     linux/scripts/patch-kernel linux

   The first argument in the command above is the location of the
   kernel source.  Patches are applied from the current directory, but
   an alternative directory can be specified as the second argument.

 - Make sure you have no stale .o files and dependencies lying around::

     cd linux
     make mrproper

   You should now have the sources correctly installed.

Software requirements
---------------------

   Compiling and running the 6.x kernels requires up-to-date
   versions of various software packages.  Consult
   :ref:`Documentation/process/changes.rst <changes>` for the minimum version numbers
   required and how to get updates for these packages.  Beware that using
   excessively old versions of these packages can cause indirect
   errors that are very difficult to track down, so don't assume that
   you can just update packages when obvious problems arise during
   build or operation.

Build directory for the kernel
------------------------------

   When compiling the kernel, all output files will per default be
   stored together with the kernel source code.
   Using the option ``make O=output/dir`` allows you to specify an alternate
   place for the output files (including .config).
   Example::

     kernel source code: /usr/src/linux-6.x
     build directory:    /home/name/build/kernel

   To configure and build the kernel, use::

     cd /usr/src/linux-6.x
     make O=/home/name/build/kernel menuconfig
     make O=/home/name/build/kernel
     sudo make O=/home/name/build/kernel modules_install install

   Please note: If the ``O=output/dir`` option is used, then it must be
   used for all invocations of make.

Configuring the kernel
----------------------

   Do not skip this step even if you are only upgrading one minor
   version.  New configuration options are added in each release, and
   odd problems will turn up if the configuration files are not set up
   as expected.  If you want to carry your existing configuration to a
   new version with minimal work, use ``make oldconfig``, which will
   only ask you for the answers to new questions.

 - Alternative configuration commands are::

     "make config"      Plain text interface.

     "make menuconfig"  Text based color menus, radiolists & dialogs.

     "make nconfig"     Enhanced text based color menus.

     "make xconfig"     Qt based configuration tool.

     "make gconfig"     GTK+ based configuration tool.

     "make oldconfig"   Default all questions based on the contents of
                        your existing ./.config file and asking about
                        new config symbols.

     "make olddefconfig"
                        Like above, but sets new symbols to their default
                        values without prompting.

     "make defconfig"   Create a ./.config file by using the default
                        symbol values from either arch/$ARCH/defconfig
                        or arch/$ARCH/configs/${PLATFORM}_defconfig,
                        depending on the architecture.

     "make ${PLATFORM}_defconfig"
                        Create a ./.config file by using the default
                        symbol values from
                        arch/$ARCH/configs/${PLATFORM}_defconfig.
                        Use "make help" to get a list of all available
                        platforms of your architecture.

     "make allyesconfig"
                        Create a ./.config file by setting symbol
                        values to 'y' as much as possible.

     "make allmodconfig"
                        Create a ./.config file by setting symbol
                        values to 'm' as much as possible.

     "make allnoconfig" Create a ./.config file by setting symbol
                        values to 'n' as much as possible.

     "make randconfig"  Create a ./.config file by setting symbol
                        values to random values.

     "make localmodconfig" Create a config based on current config and
                           loaded modules (lsmod). Disables any module
                           option that is not needed for the loaded modules.

                           To create a localmodconfig for another machine,
                           store the lsmod of that machine into a file
                           and pass it in as a LSMOD parameter.

                           Also, you can preserve modules in certain folders
                           or kconfig files by specifying their paths in
                           parameter LMC_KEEP.

                   target$ lsmod > /tmp/mylsmod
                   target$ scp /tmp/mylsmod host:/tmp

                   host$ make LSMOD=/tmp/mylsmod \
                           LMC_KEEP="drivers/usb:drivers/gpu:fs" \
                           localmodconfig

                           The above also works when cross compiling.

     "make localyesconfig" Similar to localmodconfig, except it will convert
                           all module options to built in (=y) options. You can
                           also preserve modules by LMC_KEEP.

     "make kvm_guest.config"   Enable additional options for kvm guest kernel
                               support.

     "make xen.config"   Enable additional options for xen dom0 guest kernel
                         support.

     "make tinyconfig"  Configure the tiniest possible kernel.

   You can find more information on using the Linux kernel config tools
   in Documentation/kbuild/kconfig.rst.

 - NOTES on ``make config``:

    - Having unnecessary drivers will make the kernel bigger, and can
      under some circumstances lead to problems: probing for a
      nonexistent controller card may confuse your other controllers.

    - A kernel with math-emulation compiled in will still use the
      coprocessor if one is present: the math emulation will just
      never get used in that case.  The kernel will be slightly larger,
      but will work on different machines regardless of whether they
      have a math coprocessor or not.

    - The "kernel hacking" configuration details usually result in a
      bigger or slower kernel (or both), and can even make the kernel
      less stable by configuring some routines to actively try to
      break bad code to find kernel problems (kmalloc()).  Thus you
      should probably answer 'n' to the questions for "development",
      "experimental", or "debugging" features.

Compiling the kernel
--------------------

 - Make sure you have at least gcc 5.1 available.
   For more information, refer to :ref:`Documentation/process/changes.rst <changes>`.

 - Do a ``make`` to create a compressed kernel image. It is also
   possible to do ``make install`` if you have lilo installed to suit the
   kernel makefiles, but you may want to check your particular lilo setup first.

   To do the actual install, you have to be root, but none of the normal
   build should require that. Don't take the name of root in vain.

 - If you configured any of the parts of the kernel as ``modules``, you
   will also have to do ``make modules_install``.

 - Verbose kernel compile/build output:

   Normally, the kernel build system runs in a fairly quiet mode (but not
   totally silent).  However, sometimes you or other kernel developers need
   to see compile, link, or other commands exactly as they are executed.
   For this, use "verbose" build mode.  This is done by passing
   ``V=1`` to the ``make`` command, e.g.::

     make V=1 all

   To have the build system also tell the reason for the rebuild of each
   target, use ``V=2``.  The default is ``V=0``.

 - Keep a backup kernel handy in case something goes wrong.  This is
   especially true for the development releases, since each new release
   contains new code which has not been debugged.  Make sure you keep a
   backup of the modules corresponding to that kernel, as well.  If you
   are installing a new kernel with the same version number as your
   working kernel, make a backup of your modules directory before you
   do a ``make modules_install``.

   Alternatively, before compiling, use the kernel config option
   "LOCALVERSION" to append a unique suffix to the regular kernel version.
   LOCALVERSION can be set in the "General Setup" menu.

 - In order to boot your new kernel, you'll need to copy the kernel
   image (e.g. .../linux/arch/x86/boot/bzImage after compilation)
   to the place where your regular bootable kernel is found.

 - Booting a kernel directly from a floppy without the assistance of a
   bootloader such as LILO, is no longer supported.

   If you boot Linux from the hard drive, chances are you use LILO, which
   uses the kernel image as specified in the file /etc/lilo.conf.  The
   kernel image file is usually /vmlinuz, /boot/vmlinuz, /bzImage or
   /boot/bzImage.  To use the new kernel, save a copy of the old image
   and copy the new image over the old one.  Then, you MUST RERUN LILO
   to update the loading map! If you don't, you won't be able to boot
   the new kernel image.

   Reinstalling LILO is usually a matter of running /sbin/lilo.
   You may wish to edit /etc/lilo.conf to specify an entry for your
   old kernel image (say, /vmlinux.old) in case the new one does not
   work.  See the LILO docs for more information.

   After reinstalling LILO, you should be all set.  Shutdown the system,
   reboot, and enjoy!

   If you ever need to change the default root device, video mode,
   etc. in the kernel image, use your bootloader's boot options
   where appropriate.  No need to recompile the kernel to change
   these parameters.

 - Reboot with the new kernel and enjoy.

If something goes wrong
-----------------------

If you have problems that seem to be due to kernel bugs, please follow the
instructions at 'Documentation/admin-guide/reporting-issues.rst'.

Hints on understanding kernel bug reports are in
'Documentation/admin-guide/bug-hunting.rst'. More on debugging the kernel
with gdb is in 'Documentation/dev-tools/gdb-kernel-debugging.rst' and
'Documentation/dev-tools/kgdb.rst'.