Re: [avr-gcc-list] Non initialized data in EEPROM

[Ned Konz]

dimax un wrote:

> I have an array and some config data in eeprom
>
> char config_data __attribute__ ((section (".eeprom"))) = 5;
> char eep_array[1024] __attribute__ ((section (".eeprom")));
>
> I use array as temporary storage.

In the EEPROM? So you use the various eeprom functions in avr/eeprom.h 
to read and write this area? You know you can't just use it like

eep_array[3] = 'C';

right?

> The make produces hex file for
> EEPROM image that is 1024+1 = 1025 bytes long. Actually I do not need
> eep_array to be initialized and thus do not want to burn it. Do you
> see any chance to declare some place in eeprom but make it non
> initialized and do not have it in EEPROM image hex file to minimize
> burning time.

Given that config_data is at the beginning of EEPROM, why not just use 0 
as its EEPROM address? After all, you can't directly read and write to 
EEPROM anyway; you have to use the EEPROM functions and give them 
offsets into EEPROM.

What I generally do is to define a pointer to the beginning of EEPROM by 
taking the address of the first EEPROM data item I've defined, and then 
calculate offsets from it to various data items in EEPROM.

--
Ned Konz
address@hidden
http://bike-nomad.com