Server refused to start a shell/command (Buildroot - RPi)

[Kevin Hill]

I'm sure the issue is that the kernel is not setup to create PTYs, and 
I'm not sure how to create them.
I will try your suggestion tonight.
In my googling, I read that it needs a /dev/ptmx which it uses as a 
template to create ptys...?
I haven't got one of those either.

Kernel is 3.6.11.
Using uCLib 0.9.33.x

Where should I add --disable-openpty (if I need to add that compile 
option)?

Thanks,
Kevin.



On 2015-01-14 15:50, Matt Johnston wrote:
> Thinking a bit further, try doing:
>
> mount -t devpts devpts /dev/pts
>
> That special filesystem probably needs to be mounted for openpty to
> work. I’m not sure how that works with buildroot by default.
>
> Cheers,
> Matt
>
>> On Wed 14/1/2015, at 9:54 pm, Kevin Hill 
>> <dropbear at procountsoftware.co.uk> wrote:
>>
>> I found this post from 2006 !!!!
>>
>> http://lists.ucc.gu.uwa.edu.au/pipermail/dropbear/2006q1/000366.html
>>
>> It suggests: "So.. configure with --disable-openpty helped and it 
>> works perfectly now."
>>
>> What does this do? Is it still relevant?
>>
>> Thanks,
>> Kevin
>>
>>
>> On 2015-01-14 13:31, dropbear at procountsoftware.co.uk wrote:
>>> df shows /dev having about 90MB in size and 0% used. I think /dev 
>>> type is
>>> set to tmpfs in buildroot(?). It appears to be r/w.
>>>
>>> Original email:
>>> -----------------
>>> From: Matt Johnston matt at ucc.asn.au
>>> Date: Wed, 14 Jan 2015 21:14:43 +0800
>>> To: dropbear at ucc.asn.au, dropbear at procountsoftware.co.uk
>>> Subject: Re: Server refused to start a shell/command (Buildroot - 
>>> RPi)
>>>
>>>
>>> My guess would be that /dev is full. Running “df� should show 
>>> amounts
>>> of free space.
>>>
>>> Cheers,
>>> Matt
>>>
>>>> On Wed 14/1/2015, at 5:42 am, Kevin Hill
>>> <dropbear at procountsoftware.co.uk> wrote:
>>>>
>>>> After logging in successfully the following log messages are 
>>>> indicative
>>> of my problem:
>>>>
>>>> pty_allocate: openpty: No space left on device
>>>> No pty was allocated, couldn't execute
>>>> Exit (root): Exited normally.
>>>>
>>>> PuTTY gets the messages:
>>>> Server refused to allocate pty
>>>> Server refused to start a shell/command.
>>>>
>>>> So how do I fix this?
>>>> Which device is it talking about?
>>>> My buildroot system is running from initramfs.
>>>>
>>>> Thanks,
>>>> Kevin
>>>>
>>>> On 2015-01-13 13:35, Matt Johnston wrote:
>>>>> Hi,
>>>>>
>>>>> If you run “dropbear -F -E� (kill the existing server process 
>>>>> first)
>>>>> then it will run in the foreground and print logging. That should
>>>>> suggest what’s going wrong. Alternatively it might already be 
>>>>> logging
>>>>> to somewhere in /var/log depending if syslog is running.
>>>>>
>>>>> Cheers,
>>>>> Matt
>>>>>
>>>>>> On Tue 13/1/2015, at 9:24 pm, dropbear at procountsoftware.co.uk 
>>>>>> wrote:
>>>>>>
>>>>>> I have a minimalistic buildroot system for the Raspberry Pi and 
>>>>>> would
>>> like
>>>>>> to add a dropbear ssh server to it that is started and is 
>>>>>> available from
>>>>>> boot, but for now I'm just trying to enable it manually and I'm 
>>>>>> having a
>>>>>> few problems.
>>>>>>
>>>>>> I enabled dropbear within 'make menuconfig' and rebuilt 
>>>>>> buildroot. It
>>>>>> downloaded dropbear 2013.58 which I know is a little old, but it 
>>>>>> should
>>>>>> still work, right?
>>>>>> After booting my new system I didn't use S50dropbear itself but 
>>>>>> tried
>>> to do
>>>>>> things manually. I created /etc/dropbear and within there I 
>>>>>> created the
>>>>>> keys necessary for dropbear using:
>>>>>>
>>>>>> dropbearkey -t rsa -f dropbear_rsa_host_key
>>>>>> dropbearkey -t dss -f dropbear_dss_host_key
>>>>>>
>>>>>> Then I executed dropbear (no arguments) and I could see it in 
>>>>>> the
>>> process
>>>>>> list.
>>>>>>
>>>>>> When I tried to connect to it from Putty, I got the following 
>>>>>> error:
>>>>>> "Server refused to allocate pty" which I discovered was possibly 
>>>>>> due to
>>> not
>>>>>> having a suitable mountpoint.
>>>>>> So I added the following entry to FSTAB (as per a google post I 
>>>>>> found):
>>>>>>
>>>>>>   none            /dev/pts        devpts        gid=5,mode=620   
>>>>>> 0 0
>>>>>>
>>>>>> Now the error has changed to "Server refused to start a 
>>>>>> shell/command"
>>> and
>>>>>> I haven't been able to find a solution. I can connect to the Pi 
>>>>>> using
>>>>>> WinSCP over SCP fine, but I really want a command shell using 
>>>>>> PuTTY.
>>>>>>
>>>>>> This may be more to do with my minimalistic buildroot 
>>>>>> configuration than
>>>>>> anything else, but this is my first buildroot build so I'm a bit 
>>>>>> of a
>>>>>> newbie. My starting point was the buildroot configuration used 
>>>>>> to create
>>>>>> the RPi NOOBS recovery program.
>>>>>>
>>>>>>
>>>>>> 
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