Re: [yocto] lost busybox mysteriously

From: Quentin Schulz <quentin.schulz@streamunlimited.com>
To: JH <jupiter.hce@gmail.com>
Cc: connman <connman@lists.01.org>,
	Yocto discussion list <yocto@yoctoproject.org>,
	linux-mtd <linux-mtd@lists.infradead.org>,
	Andy Pont <andy.pont@sdcsystems.com>
Subject: Re: [yocto] lost busybox mysteriously
Date: Mon, 27 Jan 2020 13:06:39 +0100	[thread overview]
Message-ID: <20200127120638.2jpgvedxecwgwz6u@qschulz> (raw)
In-Reply-To: <CAA=hcWS2ncU4+RkeLydXOnGvswshK-0iDV3cRTdFgoQ4+Oe57w@mail.gmail.com>

Hi JH,

On Mon, Jan 27, 2020 at 10:13:37PM +1100, JH wrote:
> Hi Andy,
> 
> Thanks for the response.
> 
> On 1/27/20, Andy Pont <andy.pont@sdcsystems.com> wrote:
> > JH wrote...
> >
> >>That the same problem of missing busybox was not just occurred during
> >>the device running in the middle of operation, it was also occurred
> >>during booting image from NAND, I saw several times that the first and
> >>second cycles of booting image from NAND were working well, then some
> >>following booting process would be crashed by missing busybox, then
> >>could not run whole shell commands. I have been pondering if it could
> >>be caused by NAND issue or network virus / fishy? Appreciate any
> >>clues.
> > The first step is for us to understand what “missing” means?  Have you
> > got any mechanism (U-Boot, SD card boot, etc.) that will allow you to
> > mount and look at the contents of the NAND file system?
> 
> Means that busybox was not there anymore, it mysteriously lost, all
> shell commands would no longer available. It cannot to run mount or
> any shell commands. There was two scenarios when that happened:
> 
> - In the middle of running, the device all of certain could not run
> shell commands and failed mysteriously
> 
> - During the u-boot booting kernel process, there were full errors of
> failing shell commands. Let me make it clear,  that booting error did
> not occur in the first or second kernel booting after the new image
> installation, it happened in the following kernel booting, but there
> was nothing to delete busybox accidentally, busybox was just
> mysteriously disappeared. Because I could not run ls, I did not know
> if there are other things missing. If you ask how I could know the
> busybox was missing, I ran the zImage-initramfs to boot the linux in
> RAM, then mount the ubi0 to find  out busybox was gone.
> 
> 
> > If you look at the /bin directory (ls -la /bin/busy*) what do you see?
> > Have the files been deleted? Truncated? Zero length?
> 
> Could not run ls or any shell commands when the busybox was missing.
> 

/bin/ls -la /bin/busy* ?

Maybe something is messing with the PATH environment variable. Or
something is removing the symlinks from some binaries to busybox.

> > What file system are you using on the NAND flash?  How are the devices
> > being reset during the various boot cycles?  If it is a hardware reset
> > then some file systems are less resilient to it than others but I would
> > expect in that case more fundamental boot issues.
> 
> UBIFS, most device reset or boot cycles were calling halt or reboot,
> but it sometime it could just use power cycle.
> 

IIRC, UBIFS is safe from power cycles.

Quentin

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