Re: [avrdude-dev] Why is eeprom file overwritten?

[Brian Dean]

Hi Bob,

On Wed, Sep 29, 2004 at 11:40:36AM -0400, Bob Paddock wrote:

> Today is my first adventure at using AVRDUDE to program
> EEPROM while programming the flash, using AVRDUDE 4.4.0.
> 
> I start out with two files irmem.hex for flash, and irmem.eep
> both in Intel hex format.
> 
> After using this command line:
> 
> avrdude -p atmega162 -P com1 -c stk500 -v -v \
>  -U flash:w:irmem.hex -U eeprom:w:irmem.eep
> 
> My irmem.eep file now looks like this, and my eeprom is still
> blank when I read it:
> 
> :00000001FF

I can't reproduce this.  I tested using a program file and a 400 byte
ascii file to load into the eeprom, i.e.:

     avrdude -p m128 -U flash:w:truck.hex -U eeprom:w:etf:r

It worked as expected, loading both files into flash and eeprom,
respectively, and the file used for eeprom input was not overwritten
and remained intact.

> If I leave off either -U eeprom... or both -U eeprom and -U flash,
> irmem.eep is created with the above contents, which I don't understand.

I'm not sure I under stand this.  Are you saying that if you run the
program without _any_ -U options, a file named irmem.eep is created
with the content of ':00000001FF'?

> It seems to be the signature read that is overwriting the eeprom file.
> 
> My work-around is to call the eeprom file eeprom.eep rather than  
> $(TARGET).eep.

Ah, this is a clue.  Are you running this from a Makefile?  Can you
provide the Makefile that you are using?  I wonder if another rule is
overwriting te file somewhere, i.e., I suspect this might be a bug in
your Makefile, as opposed to a bug in avrdude.

-Brian
-- 
Brian Dean
BDMICRO - ATmega128 Based MAVRIC Controllers
http://www.bdmicro.com/