17.4.1 Bootstrap Exception
A Reset exception is any exception which occurs while bootstrap code is running
(StatusBEV=1). All Reset exceptions are vectored to
0xBFC00380.
At this location, the 32-bit toolchain places a branch instruction targeting a function
named _bootstrap_exception_handler(). In the standard library, a
default weak version of this function is provided, which merely causes a software Reset.
When compiling for in-circuit debugging or emulation, the default implementation of
_bootstrap_exception_handler will first cause a software breakpoint
and then a software Reset. If the user application provides an implementation of
_bootstrap_exception_handler(), that implementation will be used
instead.