Re: [OE-core] [PATCH] initramfs-framework: remove hard dependency with busybox

[Adrian Freihofer <adrian.freihofer@gmail.com>]

On Sat, 2025-03-29 at 09:29 -0700, Khem Raj via lists.openembedded.org
wrote:
> On Sat, Mar 29, 2025 at 9:01 AM Christos Gavros via
> lists.openembedded.org <gavrosc=yahoo.com@lists.openembedded.org>
> wrote:
> > 
> > hi Adrian
> > 
> > thank you for the comment. I had a look in commits log and it looks
> > that '-c' was there since the beginning in 2008/09/10 in script
> > 'init-live.sh' and then moved in 'finish.sh' in 2011/12/08.
> > I reproduced the issue by using qemu and I described how I did it
> > in detail in bug #15716.
> > After I applied the change I tested both busybox and packagegroup-
> > core-base-utils. The boot was successful in both cases.
> > Also '-c' is an option in busybox:
> > https://www.busybox.net/downloads/BusyBox.html
> > 
> 
> -c option is to redirect the console after switching root. Some
> devices it did not work properly because util-linux version moved the
> pseudo filesystems like /dev automatically
> but busybox version did not, maybe things have changed but I would
> suggest that this operation is now happening with both switch_root
> versions with you script manually doing so.

I tested this on a device with kernel 6.1+. It seams to work as
expected also with a busybox based initramfs. Maybe you are right and
this is more like a legacy thing which can (or even should?) be
removed.

Additionally I looked into the code from busybox. The related lines
are:

	if (console) {
		close(0);
		xopen(console, O_RDWR);
		xdup2(0, 1);
		xdup2(0, 2);
	}
https://github.com/brgl/busybox/blob/master/util-linux/switch_root.c#L143

At least on my device this would just close /dev/console and open it
again. Not really useful.

I think the patch is beneficial for probably all kind of systems.
Adrian


> 
> > I will wait for more comments and then I will extend the commit
> > message and send a v2.
> > 
> > Br
> > Christos
> > 
> > 
> > 
> > 
> 
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