i use a Little Assembler Program to copy a Bootloader from Flash to RAM and it works fine so far.
The question i'm asking myself: The Program starts automatically at the Reset-Vector in Flash and defines no other Interrupt Service Vector.
For me, thats's OK, because all Interrupts are disabled but what happens if a NMI appears?
For my Controller STM32F103RB, the NMI is only sourced by a so called Clock Security System.
Because i don't use it nothing happens. But what if i change the Controller some day?
Is it good Practice to handle the NMI in such a small Program or is it not neccessary?
At least you should consider the boot-loader (or any low-level software) as SoC dependent. So if you switch to another Cortex-M which uses the NMI differently, you will have to adjust the boot-loader.
Since the NMI seems to point to a "catastrophic" error, I'd rather do a reset instead of "ignoring".
Thank you for your Reply.
I found a "Application Interrupt and Reset Control Register in the System Control Block.
Is that usually a sufficient reset, or is it better to use the SOC's Watchdog if present?
I'm not really shure, if the "non-ARM" Parts of the SOC's are sufficiently involved in this Core Reset.
To be sure, you need to check the SoC's manual. It might vary.