preserving internal EEPROM when flashing

[Schmid.M.]

Posted on January 10, 2018 at 12:16

Hello,

I changed my linker file for flashing some initial values to the internal EEPROM of my stm32l0.

MEMORY

{...EEPROM (rw)      : ORIGIN = 0x80803E8, LENGTH = 1044 }/* Define output sections */SECTIONS{  .eepromAPN :  {    /*. = ALIGN(4);*/    KEEP(*(.eepromAPN.number)) /* numberofApns */    KEEP(*(.eepromAPN*)) /* APNs */    /*. = ALIGN(4);*/  } >EEPROM

...

}

this is implemented and working nicely. but:

whenever I reflash the controller, all other EEPROM parts (between 0x8080000 and 0x80803E8) are erased.

they were not reset before these changes to the linker file.

how can I prevent this? I have some important calibration data in the EEPROM, which MUST be unchanged when flashing.

Thanks,

Michael

#stm32l0 #linker

[Schmid.M.]

Posted on January 10, 2018 at 13:27

apart from this, also the st-link utility can't flash the .bin anymore, because it is 'bigger than flash memory size'. With segger j-link it flashes perfectly... what is the difference?

[Tesla DeLorean]

Posted on January 10, 2018 at 16:30

Does it work with a .HEX file? Those at least can be sparse, so that the .BIN in fact doesn't look bigger than the FLASH when considered without regard to the EEPROM size.

[Schmid.M.]

Posted on January 12, 2018 at 11:43

Thank you. using .hex format, it flashes successfully.

Still I have the problem with erased EEPROM Memory.

in the .hex file, 0x8080000 to 0x80803E8 are not defined, I checked that. still they are erase when I flash.

If I check the 'skip erase' option in st-link Utility, it does not erase anything (which is not the best way to do it as well).

Also other flashing tools like Segger J-link seem to erase the whole memory before flashing th .hex

Are there some linker file commands which can tell the flashing tool not to erase certain parts of EEPROM?

[Schmid.M.]

Posted on January 12, 2018 at 13:49

I changed the adresses of my linker file to the second EEPROM bank and it is not erasing the unused part in bank1 anymore.