serial port weird chars ...

serial port weird chars ...

[Roberto Alejandro Espi Munoz]

Hi ... I'm currently having some trouble with displaying characters 
correctly in my terminal.  I'm using a board equivalent to the 
mini2440.  This one has a NOR and a NAND.  I connect to it over a serial 
port interface.  When I boot up the board in debug mode I'm able to see 
clearly the messages displayed by the S3C2440A USB Downloader which is 
copied in the NOR interface, I then download my barebox binary over the 
USB interface and when it boots I get a lot of weird characters on 
screen.  The console seems to respond correctly, I issue for example the 
"reset" command and it resets but I can't make out what is displayed.   
I was guessing at first a serial port configuration problem on my 
operating system (I use Linux), tried it over on Windows and same 
effect, the first bootloader works great and barebox when starting just 
mangles the characters.

The other weird problem is than when I use a USB-Serial converter to 
connect to the board's serial port everything works !

I'm currently using barebox 2012.09 and OpenSuse Linux 13.2

Any ideas ? thanks


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Re: serial port weird chars ...

[Antony Pavlov]

On Fri, 07 Aug 2015 10:41:12 -0400
Roberto Alejandro Espi Munoz <raespi@icid.cu> wrote:

> Hi ... I'm currently having some trouble with displaying characters 
> correctly in my terminal.  I'm using a board equivalent to the 
> mini2440.  This one has a NOR and a NAND.  I connect to it over a serial 
> port interface.  When I boot up the board in debug mode I'm able to see 
> clearly the messages displayed by the S3C2440A USB Downloader which is 
> copied in the NOR interface, I then download my barebox binary over the 
> USB interface and when it boots I get a lot of weird characters on 
> screen.  The console seems to respond correctly, I issue for example the 
> "reset" command and it resets but I can't make out what is displayed.   
> I was guessing at first a serial port configuration problem on my 
> operating system (I use Linux), tried it over on Windows and same 
> effect, the first bootloader works great and barebox when starting just 
> mangles the characters.
> 
> The other weird problem is than when I use a USB-Serial converter to 
> connect to the board's serial port everything works !
> 
> I'm currently using barebox 2012.09 and OpenSuse Linux 13.2
> 
> Any ideas ? thanks

You have the problem if you use your host computer motherboard serial port (no matter, Linux or Windows),
isn't it?
And no problem if you use USB-Serial dongle. So it looks like host serial port problem.

Could you try to connect the board to another host computer?

-- 
Best regards,
  Antony Pavlov

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Re: serial port weird chars ...

[Roberto Alejandro Espi Munoz]

Both scenarios work well on another host.  On my host serial port when 
interacting with one bootloader the communication is fine and with 
barebox fails.  When using a USB-serial adapter there's no problem.   
Perhaps there's a problem on my board but why does the first connection 
work and with barebox doesn't ?

On 08/07/2015 12:41 PM, Antony Pavlov wrote:
> On Fri, 07 Aug 2015 10:41:12 -0400
> Roberto Alejandro Espi Munoz <raespi@icid.cu> wrote:
>
>> Hi ... I'm currently having some trouble with displaying characters
>> correctly in my terminal.  I'm using a board equivalent to the
>> mini2440.  This one has a NOR and a NAND.  I connect to it over a serial
>> port interface.  When I boot up the board in debug mode I'm able to see
>> clearly the messages displayed by the S3C2440A USB Downloader which is
>> copied in the NOR interface, I then download my barebox binary over the
>> USB interface and when it boots I get a lot of weird characters on
>> screen.  The console seems to respond correctly, I issue for example the
>> "reset" command and it resets but I can't make out what is displayed.
>> I was guessing at first a serial port configuration problem on my
>> operating system (I use Linux), tried it over on Windows and same
>> effect, the first bootloader works great and barebox when starting just
>> mangles the characters.
>>
>> The other weird problem is than when I use a USB-Serial converter to
>> connect to the board's serial port everything works !
>>
>> I'm currently using barebox 2012.09 and OpenSuse Linux 13.2
>>
>> Any ideas ? thanks
> You have the problem if you use your host computer motherboard serial port (no matter, Linux or Windows),
> isn't it?
> And no problem if you use USB-Serial dongle. So it looks like host serial port problem.
>
> Could you try to connect the board to another host computer?
>
> -- 
> Best regards,
>    Antony Pavlov
>
> _______________________________________________
> barebox mailing list
> barebox@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/barebox



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Re: serial port weird chars ...

[Antony Pavlov]

On Fri, 07 Aug 2015 15:03:52 -0400
Roberto Alejandro Espi Munoz <raespi@icid.cu> wrote:

> Both scenarios work well on another host.  On my host serial port when 
> interacting with one bootloader the communication is fine and with 
> barebox fails.  When using a USB-serial adapter there's no problem.   
> Perhaps there's a problem on my board but why does the first connection 
> work and with barebox doesn't ?

May be barebox programs UART clocks in a slightly different way than S3C2440A USB Downloader does,
so waveform for one character is too short or too long for your host computer UART receiver?

IMHO a logic analyzer can help you. Use it to compare output mini2440 UART waveform from USB Downloader
with output UART waveform from barebox.

> 
> On 08/07/2015 12:41 PM, Antony Pavlov wrote:
> > On Fri, 07 Aug 2015 10:41:12 -0400
> > Roberto Alejandro Espi Munoz <raespi@icid.cu> wrote:
> >
> >> Hi ... I'm currently having some trouble with displaying characters
> >> correctly in my terminal.  I'm using a board equivalent to the
> >> mini2440.  This one has a NOR and a NAND.  I connect to it over a serial
> >> port interface.  When I boot up the board in debug mode I'm able to see
> >> clearly the messages displayed by the S3C2440A USB Downloader which is
> >> copied in the NOR interface, I then download my barebox binary over the
> >> USB interface and when it boots I get a lot of weird characters on
> >> screen.  The console seems to respond correctly, I issue for example the
> >> "reset" command and it resets but I can't make out what is displayed.
> >> I was guessing at first a serial port configuration problem on my
> >> operating system (I use Linux), tried it over on Windows and same
> >> effect, the first bootloader works great and barebox when starting just
> >> mangles the characters.
> >>
> >> The other weird problem is than when I use a USB-Serial converter to
> >> connect to the board's serial port everything works !
> >>
> >> I'm currently using barebox 2012.09 and OpenSuse Linux 13.2
> >>
> >> Any ideas ? thanks
> > You have the problem if you use your host computer motherboard serial port (no matter, Linux or Windows),
> > isn't it?
> > And no problem if you use USB-Serial dongle. So it looks like host serial port problem.
> >
> > Could you try to connect the board to another host computer?
> >
> > -- 
> > Best regards,
> >    Antony Pavlov
> >
> > _______________________________________________
> > barebox mailing list
> > barebox@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/barebox
> 
> 
> 
> _______________________________________________
> barebox mailing list
> barebox@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/barebox


-- 
-- 
Best regards,
  Antony Pavlov

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Re: serial port weird chars ...

[Roberto Alejandro Espi Munoz]

Supposing that's the issue, is there an option in barebox that I could 
use to circumvent this ?

Thanks for the replies ...

On 08/08/2015 11:23 AM, Antony Pavlov wrote:
> On Fri, 07 Aug 2015 15:03:52 -0400
> Roberto Alejandro Espi Munoz <raespi@icid.cu> wrote:
>
>> Both scenarios work well on another host.  On my host serial port when
>> interacting with one bootloader the communication is fine and with
>> barebox fails.  When using a USB-serial adapter there's no problem.
>> Perhaps there's a problem on my board but why does the first connection
>> work and with barebox doesn't ?
> May be barebox programs UART clocks in a slightly different way than S3C2440A USB Downloader does,
> so waveform for one character is too short or too long for your host computer UART receiver?
>
> IMHO a logic analyzer can help you. Use it to compare output mini2440 UART waveform from USB Downloader
> with output UART waveform from barebox.
>
>> On 08/07/2015 12:41 PM, Antony Pavlov wrote:
>>> On Fri, 07 Aug 2015 10:41:12 -0400
>>> Roberto Alejandro Espi Munoz <raespi@icid.cu> wrote:
>>>
>>>> Hi ... I'm currently having some trouble with displaying characters
>>>> correctly in my terminal.  I'm using a board equivalent to the
>>>> mini2440.  This one has a NOR and a NAND.  I connect to it over a serial
>>>> port interface.  When I boot up the board in debug mode I'm able to see
>>>> clearly the messages displayed by the S3C2440A USB Downloader which is
>>>> copied in the NOR interface, I then download my barebox binary over the
>>>> USB interface and when it boots I get a lot of weird characters on
>>>> screen.  The console seems to respond correctly, I issue for example the
>>>> "reset" command and it resets but I can't make out what is displayed.
>>>> I was guessing at first a serial port configuration problem on my
>>>> operating system (I use Linux), tried it over on Windows and same
>>>> effect, the first bootloader works great and barebox when starting just
>>>> mangles the characters.
>>>>
>>>> The other weird problem is than when I use a USB-Serial converter to
>>>> connect to the board's serial port everything works !
>>>>
>>>> I'm currently using barebox 2012.09 and OpenSuse Linux 13.2
>>>>
>>>> Any ideas ? thanks
>>> You have the problem if you use your host computer motherboard serial port (no matter, Linux or Windows),
>>> isn't it?
>>> And no problem if you use USB-Serial dongle. So it looks like host serial port problem.
>>>
>>> Could you try to connect the board to another host computer?
>>>
>>> -- 
>>> Best regards,
>>>     Antony Pavlov
>>>
>>> _______________________________________________
>>> barebox mailing list
>>> barebox@lists.infradead.org
>>> http://lists.infradead.org/mailman/listinfo/barebox
>>
>>
>> _______________________________________________
>> barebox mailing list
>> barebox@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/barebox
>



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