Re: [yocto] lost busybox mysteriously

[JH <jupiter.hce@xxxxxxxxx>]

On 1/27/20, Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxxx> wrote:
> 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@xxxxxxxxxxxxxx> 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.

No, could not run /bin/ls as it was  linked to  /bin/busybox.nosuid,
the /bin/busybox.nosuid was damaged for some reason.

>> > 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.

Good to know. Thank you.

> Quentin
>

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