Hi,
I'm looking to flash RIOT to an OpenMote cc2538 via the serial interface provided by the OpenBase board. I don't have a JTAG programmer at the moment so I need to do everything via the bootloader on the chip, and I'd therefore like to make sure I don't get locked out of it.
This is apparently done by ensuring the top page of flash memory (CCA) is written with a special byte sequence to enable a bootloader "backdoor", allowing one to force bootloader execution even in the presence of an existing flash image by setting a specified pin to high or low during reset. This is what I would like to achieve on the OpenMote.
I can see that this is implemented in cpu/cc2538/vectors.c, and there is a linker script in cpu/cc2538/ldscripts for the cc2538sf53 which is what the OpenMote is. However the CCA array in vectors.c is protected by an if/endif directive and is only included if UPDATE_CCA is defined. I notice that this gets defined in the header files for the cc2538dk and the ReMote, but *not* for the OpenMote.
So my question is, is this an oversight or is there a reason for it being excluded on this platform? If I define UPDATE_CCA, I can then flash the resulting binary using the script in dist/tools/cc2538-bsl without being locked out of the bootloader, no?
Cheers, Aaron