gistfile1.txt

Conditional behaviors:

1) vector_relay_table: created or not
2) vt_pointer: 4B reserved or not (and pointer set in relocate_vector_table or not)

Desired outcomes:

Application type         vt_pointer   vector_relay_table
--------------------     ----------   ------------------
mcuboot                  Y            Y
mcuboot child            Y            N
no bootloader            N            N

Let's say we have CONFIG_RUNS_AT_RESET, which defaults to y, and that
in Zephyr's Kconfig, vt_pointer reservation is something like:

config RESERVE_VT_POINTER
	bool
	default y if !RUNS_AT_RESET
	default n

Let's say that vector_relay_table is not created (N) by default via
some Kconfig.

- mcuboot sets CONFIG_RESERVE_VT_POINTER=y in a new
  prj_cortex_m0.conf, and ensures vector_relay_table=y as needed on M0
  targets, either in prj_cortex_m0.conf or via selects in its main
  Kconfig as in
  https://gist.github.com/mbolivar/dfabe2de1c4f773c52dabc5b359344b2.

- mcuboot child can bring in .conf mix-ins at cmake time as discussed
  above. these set CONFIG_RUNS_AT_RESET=n, so
  CONFIG_RESERVE_VT_POINTER=y by default. they leave
  vector_relay_table at its default, not created.

- "no bootloader" app leaves CONFIG_RUNS_AT_RESET at default y, so
  CONFIG_RESERVE_VT_POINTER=N. it also leaves vector_relay_table at
  its default, not created.