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2023-02-22Allow forcing unconditional bootconfig processingPaul E. McKenney1-1/+5
The BOOT_CONFIG family of Kconfig options allows a bootconfig file containing kernel boot parameters to be embedded into an initrd or into the kernel itself. This can be extremely useful when deploying kernels in cases where some of the boot parameters depend on the kernel version rather than on the server hardware, firmware, or workload. Unfortunately, the "bootconfig" kernel parameter must be specified in order to cause the kernel to look for the embedded bootconfig file, and it clearly does not help to embed this "bootconfig" kernel parameter into that file. Therefore, provide a new BOOT_CONFIG_FORCE Kconfig option that causes the kernel to act as if the "bootconfig" kernel parameter had been specified. In other words, kernels built with CONFIG_BOOT_CONFIG_FORCE=y will look for the embedded bootconfig file even when the "bootconfig" kernel parameter is omitted. This permits kernel-version-dependent kernel boot parameters to be embedded into the kernel image without the need to (for example) update large numbers of boot loaders. Link: https://lore.kernel.org/all/20230105005838.GA1772817@paulmck-ThinkPad-P17-Gen-1/ Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: <linux-doc@vger.kernel.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2022-12-03Documentation: Fixed a typo in bootconfig.rstKushagra Verma1-1/+1
Fixed a typo in the word 'concatenated'. Signed-off-by: Kushagra Verma <kushagra765@outlook.com> Link: https://lore.kernel.org/r/HK0PR01MB2801DA243B726141A97FE92EF8179@HK0PR01MB2801.apcprd01.prod.exchangelabs.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-04-27docs: bootconfig: Add how to embed the bootconfig into kernelMasami Hiramatsu1-3/+28
Add a description how to embed the bootconfig file into kernel. Link: https://lkml.kernel.org/r/164921228987.1090670.16843569536974147213.stgit@devnote2 Cc: Padmanabha Srinivasaiah <treasure4paddy@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Linux Kbuild mailing list <linux-kbuild@vger.kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2021-09-08docs: bootconfig: Add how to use bootconfig for kernel parametersMasami Hiramatsu1-1/+38
Add a section to describe how to use the bootconfig for specifying kernel and init parameters. This is an important section because it is the reason why this document is under the admin-guide. Link: https://lkml.kernel.org/r/163077086399.222577.5881779375643977991.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-06-10docs: bootconfig: Update for mixing value and subkeysMasami Hiramatsu1-4/+26
Update document for the mixing value and subkeys on a key. Link: https://lkml.kernel.org/r/162262196510.264090.15044943496205914148.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-01-08docs: admin-guide: bootconfig: Fix feils to failsBhaskar Chowdhury1-1/+1
s/feils/fails/p Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20210107125610.1576368-1-unixbhaskar@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-12-01docs: bootconfig: Add the endianness of fieldsMasami Hiramatsu1-1/+3
Add a description about the endianness of the size and the checksum fields. Those must be stored as le32 instead of u32. This will allow us to apply bootconfig to the cross build initrd without caring the endianness. Link: https://lkml.kernel.org/r/160583936246.547349.10964204130590955409.stgit@devnote2 Reported-by: Steven Rostedt <rostedt@goodmis.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-19docs: bootconfig: Update file format on initrd imageMasami Hiramatsu1-5/+13
To align the total file size, add padding null character when appending the bootconfig to initrd image. Link: https://lkml.kernel.org/r/160576522916.320071.4145530996151028855.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-08-03Documentation: bootconfig: Add bootconfig override operatorMasami Hiramatsu1-0/+11
Add a sentence about bootconfig override operator (":=") to bootconfig.rst. Link: https://lkml.kernel.org/r/159482884682.126704.7198860675721719878.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-03-30Merge tag 'docs-5.7' of git://git.lwn.net/linuxLinus Torvalds1-1/+1
Pull documentation updates from Jonathan Corbet: "This has been a busy cycle for documentation work. Highlights include: - Lots of RST conversion work by Mauro, Daniel ALmeida, and others. Maybe someday we'll get to the end of this stuff...maybe... - Some organizational work to bring some order to the core-api manual. - Various new docs and additions to the existing documentation. - Typo fixes, warning fixes, ..." * tag 'docs-5.7' of git://git.lwn.net/linux: (123 commits) Documentation: x86: exception-tables: document CONFIG_BUILDTIME_TABLE_SORT MAINTAINERS: adjust to filesystem doc ReST conversion docs: deprecated.rst: Add BUG()-family doc: zh_CN: add translation for virtiofs doc: zh_CN: index files in filesystems subdirectory docs: locking: Drop :c:func: throughout docs: locking: Add 'need' to hardirq section docs: conf.py: avoid thousands of duplicate label warning on Sphinx docs: prevent warnings due to autosectionlabel docs: fix reference to core-api/namespaces.rst docs: fix pointers to io-mapping.rst and io_ordering.rst files Documentation: Better document the softlockup_panic sysctl docs: hw-vuln: tsx_async_abort.rst: get rid of an unused ref docs: perf: imx-ddr.rst: get rid of a warning docs: filesystems: fuse.rst: supress a Sphinx warning docs: translations: it: avoid duplicate refs at programming-language.rst docs: driver.rst: supress two ReSt warnings docs: trace: events.rst: convert some new stuff to ReST format Documentation: Add io_ordering.rst to driver-api manual Documentation: Add io-mapping.rst to driver-api manual ...
2020-02-21bootconfig: Add append value operator supportMasami Hiramatsu1-1/+9
Add append value operator "+=" support to bootconfig syntax. With this operator, user can add new value to the key as an entry of array instead of overwriting. For example, foo = bar ... foo += baz Then the key "foo" has "bar" and "baz" values as an array. Link: http://lkml.kernel.org/r/158227283195.12842.8310503105963275584.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-21bootconfig: Prohibit re-defining value on same keyMasami Hiramatsu1-1/+10
Currently, bootconfig adds a new value on the existing key to the tail of an array. But this looks a bit confusing because an admin can easily rewrite the original value in the same config file. This rejects the following value re-definition. key = value1 ... key = value2 You should rewrite value1 to value2 in this case. Link: http://lkml.kernel.org/r/158227282199.12842.10110929876059658601.stgit@devnote2 Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> [ Fixed spelling of arraies to arrays ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-21bootconfig: Reject subkey and value on same parent keyMasami Hiramatsu1-0/+7
Reject if a value node is mixed with subkey node on same parent key node. A value node can not co-exist with subkey node under some key node, e.g. key = value key.subkey = another-value This is not be allowed because bootconfig API is not designed to handle such case. Link: http://lkml.kernel.org/r/158220115232.26565.7792340045009731803.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-21bootconfig: Add bootconfig magic word for indicating bootconfig explicitlyMasami Hiramatsu1-3/+7
Add bootconfig magic word to the end of bootconfig on initrd image for indicating explicitly the bootconfig is there. Also tools/bootconfig treats wrong size or wrong checksum or parse error as an error, because if there is a bootconfig magic word, there must be a bootconfig. The bootconfig magic word is "#BOOTCONFIG\n", 12 bytes word. Thus the block image of the initrd file with bootconfig is as follows. [Initrd][bootconfig][size][csum][#BOOTCONFIG\n] Link: http://lkml.kernel.org/r/158220112263.26565.3944814205960612841.stgit@devnote2 Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-13Documentation: bootconfig: fix Sphinx block warningRandy Dunlap1-1/+1
Fix Sphinx format warning: lnx-56-rc1/Documentation/admin-guide/bootconfig.rst:26: WARNING: Literal block expected; none found. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Link: https://lore.kernel.org/r/07b3e31f-9b1e-1876-aa60-4436e4dd6da0@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-05bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdlineSteven Rostedt (VMware)1-0/+2
As the bootconfig is appended to the initrd it is not as easy to modify as the kernel command line. If there's some issue with the kernel, and the developer wants to boot a pristine kernel, it should not be needed to modify the initrd to remove the bootconfig for a single boot. As bootconfig is silently added (if the admin does not know where to look they may not know it's being loaded). It should be explicitly added to the kernel cmdline. The loading of the bootconfig is only done if "bootconfig" is on the kernel command line. This will let admins know that the kernel command line is extended. Note, after adding printk()s for when the size is too great or the checksum is wrong, exposed that the current method always looked for the boot config, and if this size and checksum matched, it would parse it (as if either is wrong a printk has been added to show this). It's better to only check this if the boot config is asked to be looked for. Link: https://lore.kernel.org/r/CAHk-=wjfjO+h6bQzrTf=YCZA53Y3EDyAs3Z4gEsT7icA3u_Psw@mail.gmail.com Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-22Documentation: bootconfig: Fix typos in bootconfig documentationMasami Hiramatsu1-15/+17
Fix typos in bootconfig.rst according to Randy's suggestions. Link: http://lkml.kernel.org/r/157949059219.25888.16939971423610233631.stgit@devnote2 Suggested-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13Documentation: tracing: Add boot-time tracing documentMasami Hiramatsu1-0/+2
Add a documentation about boot-time tracing options in boot config. Link: http://lkml.kernel.org/r/157867246028.17873.8047384554383977870.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13Documentation: bootconfig: Add a doc for extended boot configMasami Hiramatsu1-0/+184
Add a documentation for extended boot config under admin-guide, since it is including the syntax of boot config. Link: http://lkml.kernel.org/r/157867230658.17873.9309879174829924324.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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