Re: [Buildroot] [PATCH v4 1/3] package/tinyinit: new package

["Yann E. MORIN" <yann.morin.1998@free.fr>]

Dario, All,

On 2024-08-31 14:08 +0200, Dario Binacchi spake thusly:
> This package contains a Linux init script suitable for resource-limited
> systems which can be used as an alternative to the one provided by
> Busybox.
> 
> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> Cc: Yann E. MORIN <yann.morin.1998@free.fr>
> Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
> ---
[--SNIP--]
> diff --git a/package/tinyinit/Config.in b/package/tinyinit/Config.in
> new file mode 100644
> index 000000000000..f68b030e7e0f
> --- /dev/null
> +++ b/package/tinyinit/Config.in
> @@ -0,0 +1,8 @@
> +config BR2_PACKAGE_TINYINIT
> +	bool "tinyinit"
> +	depends on BR2_INIT_TINYINIT
> +	imply BR2_PACKAGE_BUSYBOX

As discussed with together with the other maintainers at the dev-days,
we concluded that we do not want to use 'imply', at least not in this
case.

Indeed, imply is a soft requirement, that makes the target enabled by
default, but can still be de-selectable. In our case, busybox is already
enabled by default, so 'imply' has no impact.

Applied to master with 'imply' dropped, thanks!

Regards,
Yann E. MORIN.

> +	help
> +	  A Linux tiny initialization script suitable for resource
> +	  limited systems, which can be used as an alternative to the
> +	  one provided by Busybox.
> diff --git a/package/tinyinit/init b/package/tinyinit/init
> new file mode 100644
> index 000000000000..fbcb481010c2
> --- /dev/null
> +++ b/package/tinyinit/init
> @@ -0,0 +1,32 @@
> +#!/bin/sh
> +
> +# This script replaces the default busybox init process to avoid having that
> +# process staying alive and sleeping in the background, (uselessly) consuming
> +# precious memory.
> +
> +# Mount procfs and sysfs
> +/bin/mount -t proc proc /proc
> +/bin/mount -t sysfs sysfs /sys
> +
> +# When the kernel is directly booted, devtmpfs is not automatically mounted.
> +# Manually mount it if needed.
> +devmnt=$(mount | grep -c devtmpfs)
> +if [ "${devmnt}" -eq 0 ]; then
> +    /bin/mount -t devtmpfs devtmpfs /dev
> +fi
> +
> +# Use the /dev/console device node from devtmpfs if possible to not
> +# confuse glibc's ttyname_r().
> +# This may fail (E.G. booted with console=), and errors from exec will
> +# terminate the shell, so use a subshell for the test
> +if (exec 0</dev/console) 2>/dev/null; then
> +    exec 0</dev/console
> +    exec 1>/dev/console
> +    exec 2>/dev/console
> +fi
> +
> +# Clear memory to reduce page fragmentation
> +echo 3 > /proc/sys/vm/drop_caches
> +
> +# Finally, let's start an interactive shell
> +exec /bin/sh
> diff --git a/package/tinyinit/tinyinit.mk b/package/tinyinit/tinyinit.mk
> new file mode 100644
> index 000000000000..ac1f0f736e38
> --- /dev/null
> +++ b/package/tinyinit/tinyinit.mk
> @@ -0,0 +1,13 @@
> +################################################################################
> +#
> +# tinyinit
> +#
> +################################################################################
> +
> +define TINYINIT_INSTALL_TARGET_CMDS
> +	$(INSTALL) -m 0755 -D $(TINYINIT_PKGDIR)/init $(TARGET_DIR)/sbin/init
> +	# Downside: In non-initramfs systems the symlink isn't used/needed
> +	(cd $(TARGET_DIR); ln -sf /sbin/init init)
> +endef
> +
> +$(eval $(generic-package))
> diff --git a/system/Config.in b/system/Config.in
> index d7d59db47db7..974152bd23e6 100644
> --- a/system/Config.in
> +++ b/system/Config.in
> @@ -165,6 +165,15 @@ config BR2_INIT_TINI
>  
>  	  https://github.com/krallin/tini
>  
> +config BR2_INIT_TINYINIT
> +	bool "tiny init"
> +	select BR2_PACKAGE_TINYINIT
> +	select BR2_PACKAGE_SKELETON_INIT_NONE if BR2_ROOTFS_SKELETON_DEFAULT
> +	help
> +	  A Linux tiny initialization script suitable for resource
> +	  limited systems, which can be used as an alternative to the
> +	  one provided by Busybox.
> +
>  config BR2_INIT_NONE
>  	bool "Custom (none)"
>  	select BR2_PACKAGE_SKELETON_INIT_NONE if BR2_ROOTFS_SKELETON_DEFAULT
> -- 
> 2.43.0
> 
> _______________________________________________
> buildroot mailing list
> buildroot@buildroot.org
> https://lists.buildroot.org/mailman/listinfo/buildroot

-- 
.-----------------.--------------------.------------------.--------------------.
|  Yann E. MORIN  | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software  Designer | \ / CAMPAIGN     |  ___               |
| +33 561 099 427 `------------.-------:  X  AGAINST      |  \e/  There is no  |
| http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL    |   v   conspiracy.  |
'------------------------------^-------^------------------^--------------------'
_______________________________________________
buildroot mailing list
buildroot@buildroot.org
https://lists.buildroot.org/mailman/listinfo/buildroot