Custom Kernel - Revision history

Darkfader: /* Configuring kernel */

2026-03-29T16:03:09Z

Configuring kernel

← Older revision		Revision as of 16:03, 29 March 2026
Line 125:		Line 125:

	You want to remove <code>ncurses-dev</code>. When you are done, it will be stored in ''.config'' which you need to again override the {{path\|lts.ARCH.config}} file.		You want to remove <code>ncurses-dev</code>. When you are done, it will be stored in ''.config'' which you need to again override the {{path\|lts.ARCH.config}} file.

			<pre>
			cp .config ../../lts-my-kernel.x86_64.config
			</pre>

	When you are done updating the {{path\|config-NAME.ARCH}}, you need to update sums:		When you are done updating the {{path\|config-NAME.ARCH}}, you need to update sums:

Darkfader: /* Configuring kernel */

2026-03-29T15:31:10Z

Configuring kernel

← Older revision		Revision as of 15:31, 29 March 2026
Line 101:		Line 101:

	There are multiple ways to prepare and change kernel config. The basic one is to just edit your custom config file. You can also attempt to create a config tailored for your currently running system and modules.		There are multiple ways to prepare and change kernel config. The basic one is to just edit your custom config file. You can also attempt to create a config tailored for your currently running system and modules.

			Extract your kernel and apply the standard patches:

			<pre>
			abuild fetch && abuild unpack && abuild prepare
			</pre>

	To create a kernel config based on your currently running PC, use:		To create a kernel config based on your currently running PC, use:

John3-16: "Work-in-progress" flag removed further to no objections; see Talk:Custom Kernel/Page ready for regular release?

2026-02-01T02:05:47Z

"Work-in-progress" flag removed further to no objections; see Talk:Custom Kernel/Page ready for regular release?

← Older revision		Revision as of 02:05, 1 February 2026
Line 1:		Line 1:
	~~{{Draft}}~~

	This process of building a '''custom configured kernel''' assumes you are running on Alpine Linux utilizing abuild & aports.		This process of building a '''custom configured kernel''' assumes you are running on Alpine Linux utilizing abuild & aports.

Prabuanand: Undo revision 31901 by Prabuanand (talk)

2025-12-31T04:45:00Z

Undo revision 31901 by Prabuanand (talk)

← Older revision		Revision as of 04:45, 31 December 2025
Line 1:		Line 1:
	This process of building a '''custom configured kernel''' assumes you are running on Alpine Linux utilizing [[abuild]] & [[aports~~]]. Alpine Linux has several [[Kernels\|kernel]]~~.		{{Draft}}

			This process of building a '''custom configured kernel''' assumes you are running on Alpine Linux utilizing abuild & aports.

	== But why? ==		== But why? ==
Line 5:		Line 7:
	You want to build a custom kernel to enable experimental hardware or features or outdated hardware, to reduce bloat further, to tune the kernel to the hardware.		You want to build a custom kernel to enable experimental hardware or features or outdated hardware, to reduce bloat further, to tune the kernel to the hardware.

	The lts kernel for most Alpine ARCHs uses defaults to balance throughput at the expense of some responsiveness, and support for many devices. You can tweak the kernel for desktop use and low latency and responsiveness.		The lts kernel for most Alpine ARCHs uses defaults to balance throughput at the expense of some responsiveness, and support for many devices. You can tweak the kernel for desktop use and low latency and responsiveness.

	You should disable modules to increase security. By default, Alpine will install modules but not disable most of them. Disabling modules will reduce an DMA attack but not eliminate it completely. If you have a newer processor with VT-d, you can mitigate as long as you:		You should disable modules to increase security. By default, Alpine will install modules but not disable most of them. Disabling modules will reduce an DMA attack but not eliminate it completely. If you have a newer processor with VT-d, you can mitigate as long as you:

Prabuanand: removed draft notice

2025-12-31T04:23:43Z

removed draft notice

← Older revision		Revision as of 04:23, 31 December 2025
Line 1:		Line 1:
	~~{{Draft}}~~		This process of building a '''custom configured kernel''' assumes you are running on Alpine Linux utilizing [[abuild]] & [[aports]]. Alpine Linux has several [[Kernels\|kernel]].

	This process of building a '''custom configured kernel''' assumes you are running on Alpine Linux utilizing abuild & aports.

	== But why? ==		== But why? ==
Line 7:		Line 5:
	You want to build a custom kernel to enable experimental hardware or features or outdated hardware, to reduce bloat further, to tune the kernel to the hardware.		You want to build a custom kernel to enable experimental hardware or features or outdated hardware, to reduce bloat further, to tune the kernel to the hardware.

	The lts kernel for most Alpine ARCHs uses defaults to balance throughput at the expense of some responsiveness, and support for many devices. You can tweak the kernel for desktop use and low latency and responsiveness.		The lts kernel for most Alpine ARCHs uses defaults to balance throughput at the expense of some responsiveness, and support for many devices. You can tweak the kernel for desktop use and low latency and responsiveness.

	You should disable modules to increase security. By default, Alpine will install modules but not disable most of them. Disabling modules will reduce an DMA attack but not eliminate it completely. If you have a newer processor with VT-d, you can mitigate as long as you:		You should disable modules to increase security. By default, Alpine will install modules but not disable most of them. Disabling modules will reduce an DMA attack but not eliminate it completely. If you have a newer processor with VT-d, you can mitigate as long as you:

Prabuanand: added wiki templates

2025-12-30T16:03:06Z

added wiki templates

← Older revision		Revision as of 16:03, 30 December 2025
Line 41:		Line 41:
	\| master		\| master
	\|-		\|-
	\| ~~3.23.0~~		\|{{#expr:{{AlpineLatest}}}}
	\| ~~3.23~~-stable		\|{{#expr:{{AlpineLatest}}}}-stable
	\|-		\|-
	\|}		\|}
Line 48:		Line 48:
	The following is required to get access to the {{path\|APKBUILD}} released for that version of Alpine and which you will create a commit for.		The following is required to get access to the {{path\|APKBUILD}} released for that version of Alpine and which you will create a commit for.

	If you are on ~~3.23~~ do:		If you are on {{#expr:{{AlpineLatest}}}} do:

	{{cmd\|$ git checkout -b ~~3.23~~-stable origin/~~3.23~~-stable}}		{{cmd\|$ git checkout -b {{#expr:{{AlpineLatest}}}}-stable origin/{{#expr:{{AlpineLatest}}}}-stable}}

	If you are on Edge do:		If you are on Edge do:
Line 60:		Line 60:
	You can use {{pkg\|linux-lts}} but what you should do is create a local branch by doing:		You can use {{pkg\|linux-lts}} but what you should do is create a local branch by doing:

	For ~~Alpine 3.23 (~~linux-lts ~~- 6.18)~~:		For <var>linux-lts</var> kernel on Alpine {{#expr:{{AlpineLatest}}}}:

	{{cmd\|$ git checkout -b my-custom-kernel origin/~~3.23~~-stable}}		{{cmd\|$ git checkout -b my-custom-kernel origin/{{#expr:{{AlpineLatest}}}}-stable}}

	For Alpine Edge:		For Alpine Edge:
Line 68:		Line 68:
	{{cmd\|$ git checkout -b my-custom-kernel}}		{{cmd\|$ git checkout -b my-custom-kernel}}

	Doing it this way, you do less work in maintaining. All you need to do is keep ''master'' or ''~~3.23~~-stable'' in sync[https://help.github.com/articles/syncing-a-fork/][https://help.github.com/articles/configuring-a-remote-for-a-fork/] and merge any conflicts.		Doing it this way, you do less work in maintaining. All you need to do is keep ''master'' or ''{{#expr:{{AlpineLatest}}}}-stable'' in sync[https://help.github.com/articles/syncing-a-fork/][https://help.github.com/articles/configuring-a-remote-for-a-fork/] and merge any conflicts.

	First switch to the branch by doing		First switch to the branch by doing:{{cmd\|$ git checkout my-custom-kernel}}
	~~<code>~~git checkout my-custom-kernel~~</code>.~~
	Then, you need to navigate to the {{path\|main/linux-lts}} folder where you should see a APKBUILD and some config- files.		Then, you need to navigate to the {{path\|main/linux-lts}} folder where you should see a APKBUILD and some config- files.

Line 289:		Line 288:
	== Testing ==		== Testing ==

	In case your new kernel may be missing a module and can't boot it is generally a good idea to keep the default <code>linux-lts</code> so make sure you have it installed~~... <code>~~apk add {{pkg\|linux-lts}}~~</code>.~~		In case your new kernel may be missing a module and can't boot it is generally a good idea to keep the default <code>linux-lts</code>, so make sure you have it installed using the command: {{Cmd\|# apk add {{pkg\|linux-lts}}}}

	Normally during the installation using with ''apk'' there are tools that will update initramfs and a boot loader automatically for you. For easier debugging you may want to change boot loader config and remove <code>quiet</code> from linux command line in ~~<code>~~/etc/default/grub~~</code>~~ or ~~<code>~~/etc/update-extlinux.conf~~</code>~~.		Normally during the installation using with [[apk]], there are tools that will update initramfs and a boot loader automatically for you. For easier debugging you may want to change boot loader config and remove <code>quiet</code> from linux command line in {{Path\|/etc/default/grub}} or {{Path\|/etc/update-extlinux.conf}}.
	Or perhaps you want to change other kernel options in ~~<code>~~/etc/mkinitfs/mkinitfs.conf~~</code> - please~~ remember to generate initramfs and update your bootloader manually, eg:		Or perhaps you want to change other kernel options in {{Path\|/etc/mkinitfs/mkinitfs.conf}}. Please remember to generate initramfs and update your bootloader manually, eg:
	<~~pre~~>		{{Cmd\|<nowiki># mkinitfs
	# mkinitfs		# grub-mkconfig -o /boot/grub/grub.cfg</nowiki>}}
	# grub-mkconfig -o /boot/grub/grub.cfg
	</~~pre~~>

	In case something goes wrong with a boot process it is also a good idea to have a bootable rescue Alpine USB ready.		In case something goes wrong with a boot process it is also a good idea to have a bootable rescue Alpine USB ready.

Pawciobiel: rephrase configuration

2025-12-30T09:52:52Z

rephrase configuration

← Older revision		Revision as of 09:52, 30 December 2025
Line 102:		Line 102:
	== Configuring kernel ==		== Configuring kernel ==

	~~Attempt~~ to create a config for your currently running system and modules ~~first~~.		There are multiple ways to prepare and change kernel config. The basic one is to just edit your custom config file. You can also attempt to create a config tailored for your currently running system and modules.

	To create a kernel config based on your currently running PC, use:		To create a kernel config based on your currently running PC, use:
	<~~code~~>make localmodconfig</~~code~~>		<pre>
			make localmodconfig
			</pre>
	This command reads your current kernel's configuration from /proc/config.gz (if available) or /boot/config-* and creates a .config file that includes only the modules currently loaded on your system. This results in a minimal configuration tailored to your hardware.		This command reads your current kernel's configuration from /proc/config.gz (if available) or /boot/config-* and creates a .config file that includes only the modules currently loaded on your system. This results in a minimal configuration tailored to your hardware.
	Alternatively, you can use:		Alternatively, you can use:
	<~~code~~>make localyesconfig</~~code~~>		<pre>make localyesconfig</pre>
	This is similar to ''localmodconfig'', but instead of building features as modules (m), it builds them directly into the kernel (y), which can result in a larger kernel image but eliminates the need for separate module files.		This is similar to ''localmodconfig'', but instead of building features as modules (m), it builds them directly into the kernel (y), which can result in a larger kernel image but eliminates the need for separate module files.
	Note: Before running either command, make sure you have all the hardware you want to support actively in use (USB devices plugged in, network cards active, etc.) so their modules are loaded and included in the configuration.		Note: Before running either command, make sure you have all the hardware you want to support actively in use (USB devices plugged in, network cards active, etc.) so their modules are loaded and included in the configuration.
Line 114:		Line 116:
	The alternative is to use the kernel configuration menu in the build-NAME folder, but before you do that you need to <code>sudo apk add {{pkg\|ncurses-dev}}</code>		The alternative is to use the kernel configuration menu in the build-NAME folder, but before you do that you need to <code>sudo apk add {{pkg\|ncurses-dev}}</code>

	After you are done using the menu in the build-NAME folder by doing <~~code~~>make menuconfig</~~code~~>~~, you~~ want to remove <code>ncurses-dev</code>. When you are done, it will be stored in ''.config'' which you need to again override the {{path\|lts.ARCH.config}} file. When you are done updating the {{path\|config-NAME.ARCH}}, you need to do <~~code~~>abuild checksum</~~code~~>.		After you are done using the menu in the build-NAME folder by doing:

			<pre>make menuconfig</pre>

			You want to remove <code>ncurses-dev</code>. When you are done, it will be stored in ''.config'' which you need to again override the {{path\|lts.ARCH.config}} file.

			When you are done updating the {{path\|config-NAME.ARCH}}, you need to update sums:
			<pre>
			abuild checksum
			</pre>

	The options in the kernel config are typically defaults. If your device is old, it may be set to n by default.		The options in the kernel config are typically defaults. If your device is old, it may be set to n by default.

Pawciobiel: rephrase testing description

2025-12-30T09:46:48Z

rephrase testing description

← Older revision		Revision as of 09:46, 30 December 2025
Line 278:		Line 278:
	== Testing ==		== Testing ==

	~~Before you test, you should install~~ the lts ~~kernel too, using~~ <code>apk add {{pkg\|linux-lts}}</code>~~. You may be missing a module and can't boot, so you use the other kernel as the fallback boot kernel~~.		In case your new kernel may be missing a module and can't boot it is generally a good idea to keep the default <code>linux-lts</code> so make sure you have it installed... <code>apk add {{pkg\|linux-lts}}</code>.

	Normally during the installation using with ''apk'' there are tools that will update initramfs and a boot loader automatically for you. For easier debugging you may want to change boot loader config and remove <code>quiet</code> from linux command line in <code>/etc/default/grub</code> or <code>/etc/update-extlinux.conf</code>.		Normally during the installation using with ''apk'' there are tools that will update initramfs and a boot loader automatically for you. For easier debugging you may want to change boot loader config and remove <code>quiet</code> from linux command line in <code>/etc/default/grub</code> or <code>/etc/update-extlinux.conf</code>.
Line 287:		Line 287:
	</pre>		</pre>

	~~To test, first you should make~~ a bootable Alpine USB ~~image. Then, when you have your rescue USB done, you <code>reboot</code> the computer~~.		In case something goes wrong with a boot process it is also a good idea to have a bootable rescue Alpine USB ready.

	~~To test it,~~ you ~~basically do trial~~ and ~~error. Sometimes your config is missing something if you want to have a bare minimum setting~~.		Once you have the default lts kernel and rescue USB <code>reboot</code> the computer.

	If you are curious about correctness testing, some kernel modules or components do preform self tests at the beginning of the boot process. The tools may have test suites that you run with the make command.		If you are curious about correctness testing, some kernel modules or components do preform self tests at the beginning of the boot process. The tools may have test suites that you run with the make command.

Pawciobiel: Updated installing

2025-12-30T09:38:00Z

Updated installing

← Older revision		Revision as of 09:38, 30 December 2025
Line 273:		Line 273:
	== Installing ==		== Installing ==

	To install ~~it you do~~ a ~~{{ic\|doas apk add linux-NAME}} where NAME is~~ your ~~custom kernel name~~.		If the build was successful the kernel packages are located in <code>~/packages/main/ARCH</code>
			You probably already know how to install a package in your Alpine Linux...

	== Testing ==		== Testing ==

Pawciobiel: Update building with FLAVOR

2025-12-30T09:35:28Z

Update building with FLAVOR

← Older revision		Revision as of 09:35, 30 December 2025
Line 253:		Line 253:
	PACKAGER_PRIVKEY="/home/MY_USER_HERE/.abuild/my-email@mydomain.com-ID.rsa"		PACKAGER_PRIVKEY="/home/MY_USER_HERE/.abuild/my-email@mydomain.com-ID.rsa"
	USE_CCACHE=1		USE_CCACHE=1
			</pre>
			Please note that kernel build process may not use some of the settings you set in `abuild.conf` so in order to customize compiler or linker and/or it's flags you may need to edit APKBUILD.
			If you have your config ready, first try building with:

			<pre>
			FLAVOR=lts-my_custom abuild -rK 2>&1 \| tee build1.log
	</pre>		</pre>

	~~If you have your config ready, first try building with <code>abuild -rK</code> which~~ install most of the dependencies and keep buildtime temp dirs and files (srcdir/pkgdir/deps).		This will install most of the dependencies and keep buildtime temp dirs and files (srcdir/pkgdir/deps).

	If it complains about a dependency like {{pkg\|elfutils-dev}} use <code>-rKd</code>.		If it complains about a dependency like {{pkg\|elfutils-dev}} use <code>-rKd</code>.
	Then, when it prompts for values for new found config options just hold enter till it starts compiling the kernel.		Then, when it prompts for values for new found config options just hold enter till it starts compiling the kernel.
	Unless you removed or commented out <code>virt.*.config</code> configs		Unless you use <code>FLAVOR</code> or removed or commented out <code>virt.*.config</code> configs in APKBUILD there should be two sets one for -lts and the other for the -virt.
	there should be two sets one for -lts and the other for the -virt.
	Just {{Key\|Ctrl}}+{{Key\|C}} out of the compilation process after		Just {{Key\|Ctrl}}+{{Key\|C}} out of the compilation process after
	the second set so you can further customize the config.		the second set so you can further customize the config.