Hi
I have been using the DFU for quite a while. I adapted the boot loader to my hardware and compiled it using Keil. All my other code is written in another environment using gcc, so I wanted to be able to do the boot loader in that same environment.
I managed to get the boot loader compiled and working, however, still got 2 issues:
- apparently, even with the maximum optimization, the size is really at then limit, so I cannot add extra things apparently - is there a way to overcome this?
- a bigger issue for me is that, when using the bootloader compiled with gcc, I cannot start my program after programming boot loader, soft device and application hex files using a JlinkExe script, I need to program the application using the DFU; with the Keil version that was not necessary;
After reading through the forum, it seems that in the gcc version, no valid flag is written tot he BOOTLOADER_SETTINGS flash space. I tried to fix that by including a write of the good value at this position, as suggested here but apparently that flash location was already written to 0, so cannot write to it anymore, that location or page should be erased first.
Can anyone help me solve this issue?
Is there a way of erasing and re-writing a single byte in flash using JlinkExe? And is this 1 byte the only thing checked at startup of the bootloader, or are there some other integrity checks? Or is the only way editing the boot loader hex file? How does the Keil project do this, make sure the application valid flag is already set in the hex file?
For information: I am using SDK7.2.0 on custom hardware, and I am doing all my development on Mac OSX.
