[ECOS] redboot with console baudrate 115200

[ECOS] redboot with console baudrate 115200

[Dirk Eibach]

Hello,

I'm trying to get redboot running with a console baudrate of 115200 on 
an Atmel EB40A board.

First everything looks fine:
I can read the output from redboot after power-up, enter commands and 
these things.

The problem is that file downloads via xmodem don't work with the higher 
baudrate.

Any suggestions ?


Best regards

Matthias




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Re: [ECOS] redboot with console baudrate 115200

[Andrew Lunn]

On Fri, May 05, 2006 at 01:55:02PM +0200, Dirk Eibach wrote:
> Hello,
> 
> I'm trying to get redboot running with a console baudrate of 115200 on 
> an Atmel EB40A board.
> 
> First everything looks fine:
> I can read the output from redboot after power-up, enter commands and 
> these things.
> 
> The problem is that file downloads via xmodem don't work with the higher 
> baudrate.
> 
> Any suggestions ?

Probably you are overflowing the receive buffer and so causing CRC
errors. Try a slower speed.

        Andrew

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Re: [ECOS] redboot with console baudrate 115200

[Jürgen Lambrecht]

Hello,

on my custom board based on eb55 (also AT91M55800), I have the same 
problem: Redboot works fine with all baudrates, but ymodem or xmodem not.
The highest speed I can use is 19200 baud.
Also Vince Z. has the same problem. Like him, I now also use TFTP instead.

The strange thing is that on the eb55 demoboard, 38400 downloads are no 
problem.

Kind regards,
Juergen


Andrew Lunn wrote:
> On Fri, May 05, 2006 at 01:55:02PM +0200, Dirk Eibach wrote:
> 
>>Hello,
>>
>>I'm trying to get redboot running with a console baudrate of 115200 on 
>>an Atmel EB40A board.
>>
>>First everything looks fine:
>>I can read the output from redboot after power-up, enter commands and 
>>these things.
>>
>>The problem is that file downloads via xmodem don't work with the higher 
>>baudrate.
>>
>>Any suggestions ?
> 
> 
> Probably you are overflowing the receive buffer and so causing CRC
> errors. Try a slower speed.
> 
>         Andrew
> 

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Re: [ECOS] redboot with console baudrate 115200

[Andrew Lunn]

On Wed, Jun 07, 2006 at 10:55:09AM +0200, J?rgen Lambrecht wrote:
> Hello,
> 
> on my custom board based on eb55 (also AT91M55800), I have the same 
> problem: Redboot works fine with all baudrates, but ymodem or xmodem not.
> The highest speed I can use is 19200 baud.
> Also Vince Z. has the same problem. Like him, I now also use TFTP instead.
> 
> The strange thing is that on the eb55 demoboard, 38400 downloads are no 
> problem.

How accurate is your boad rate generator? I think the older AT91 cores
had a limited baud rate generator which could not always generate the
exact baud rate needed. It could be the error is too big for higher
boad rates.

     Andrew

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Re: [ECOS] redboot with console baudrate 115200

[GONZALEZ Laurent]

On Wed, 07 Jun 2006 10:55:09 +0200
Jürgen Lambrecht <Jurgen.Lambrecht@tiscali.be> wrote:

> 
> The strange thing is that on the eb55 demoboard, 38400 downloads are no 
> problem.

Do both boards use the same quartz ? Is internal PLL programmed in a similar way ? Are the timing/width of SRAM or flash access identical ?

It may look strange, but at 38400, the one-char buffer time-frame does not meet the critical path of xmodem routine, and sometime char is lost. Remind that this path increases a lot if you try to download an elf (compared to raw).

A few years ago there has been discussion here about a buffered serial driver (in kernel configurations, using interrupts), but I am not sure that the hal-serial used by redboot has been enhanced in the same way.

best regards.

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GONZALEZ Laurent
-----------------------------------------
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-----------------------------------------
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