Is there anyway I can have Optiboot bootloader AND read/verify fuses set so eeprom cant be readback ?
I tried to change boards.txt to write a new bootloader with adjusted fuses and the IDE didnt like it
Anyone know how ?
Is there anyway I can have Optiboot bootloader AND read/verify fuses set so eeprom cant be readback ?
I tried to change boards.txt to write a new bootloader with adjusted fuses and the IDE didnt like it
Anyone know how ?
you can always disable the SPI interface and the reset pin
@mcnobby, you have been here more than one day...
Date Registered: Jun 29, 2012, 05:46 am
You have actively participated during that time...
Posts: 950 (0.621 per day)
You know you are not going to get away with this vague description...
mcnobby:
I tried to change boards.txt to write a new bootloader with adjusted fuses and the IDE didnt like it
So...
What did you change in boards.txt?
What did the IDE not like? What was the error message?
Smacked wrist accepted
I shall repeat my test and come back with a non-vague answer
Bob
Did you mean EEPROM (non volatile data memory) or did you mean the flash memory (code)?
Note that the bootloader itself doesn't pay any attention to the lock bit fuses; you can still read/write the flash using the bootloader, even if SPI and paralllel read/write is prohibited.
Bootloader access to flash is still limited by the BLB bits in the lock bits, per pg 285~286.
But that's flash.
EEPROM read/write can be disabled with the lockbits (though one can still erase the chip and reprogram it if SPI programming is enabled).
Optiboot (at least the version normally used - it can be built ) doesn't support reading or writing from the EEPROM.
westfw:
Did you mean EEPROM (non volatile data memory) or did you mean the flash memory (code)?
Note that the bootloader itself doesn't pay any attention to the lock bit fuses; you can still read/write the flash using the bootloader, even if SPI and paralllel read/write is prohibited.
Thanks All
I'd probably like to protect the flash AND EEPROM from readback over SPI
and since the bootloader only writes to the flash and not EEPROM (?) I use certain bytes in EEPROM that the bootloaded software must read correctly before running
Its not totally unbreakable, but at least its a start