Re: [OE-core] is "poky" distro defined to use "sysvinit" as INIT_MANAGER?

[Michael Opdenacker <michael.opdenacker@bootlin.com>]

Am 03.01.23 um 15:41 schrieb Michael Opdenacker via lists.openembedded.org:
> Hello Richard,
>
> Trying to improve the documentation about the selection of the init 
> system, I'm jumping back to this old conversation, following a change 
> that you made (https://lists.yoctoproject.org/g/poky/message/12760).
>
> Am 06.07.22 um 18:40 schrieb Khem Raj:
>> On Wed, Jul 6, 2022 at 12:38 PM Robert P. J. Day 
>> <rpjday@crashcourse.ca> wrote:
>>>
>>>    not sure why i never noticed this before, but i started a new
>>> project from the poky layer (not OE), and realized that poky.conf
>>> explicitly sets:
>>>
>>>    INIT_MANAGER = "sysvinit"
>>>
>>> which can't be overridden in my local.conf. if i want systemd, i guess
>>> i can initialize my project from the OE layer, and i also notice that
>>> i could use poky-altcfg.conf.
>>>
>>>    but is there a reason that the default poky-based project fixes
>>> INIT_MANAGER to "sysvinit". perhaps just for simplicity?
>>>
>> poky defaults to sysvinit.
>> poky has poky-alt distro fi you want to use say systemd
>
> But why not setting INIT_MANAGER with "?=" instead of "=" in poky.conf?
>
> This way, we could just override INIT_MANAGER from local.conf.
>
> I checked that the generated system works. This would make things 
> easier to document, unless I'm missing other reasons.


Richard told me on IRC that, from memory, this was set because of 
interference poky-altcfg (if I understood correctly).

I understand one recommended way to have systemd instead of sysvinit in 
Poky is to use "poky-altcfg" instead of "poky" as distro.

Similarly, I guess I should use "poky-tiny" if I want to use 
"mdev-busybox" as INIT_MANAGER.

Then, I guess I'll document something like this:

  * With the OpenEmbedded build system, you can choose your init system
    by setting INIT_MANAGER to "sysvinit", "systemd", "busybox-mdev" or
    "none"
  * BUT if you're using Poky, that won't work, so your options will be
    to use either "poky" (sysvinit), "poky-altcfg" (systemd) or
    "poky-tiny" (mdev-busybox).

Does this sound like the right way to document this?

Cheers
Michael.

-- 
Michael Opdenacker, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com