target: are we running algorithm code?
Fixing one bug can easily uncover another .... in this case, making sure that we properly invalidate some cached NOR state when resuming arbitrary target code turned up an issue when the code wasn't quite arbitrary (and we couldn't know that, but some parts of OpenOCD assumed the cache would not be invalidated. Specifically: some flash drivers (like CFI) update that state in loops with downloaded algorithms, thus invalidating the state as it's probed. + Add a new target state flag, to record whether the target is running downloaded algorithm code. + Use that flag to add a special case: "trust" downloaded algorithms not to corrupt that cached state, bypassing cache invalidation. Also update some of the documentation to stipulate that this flavor of trustworthiness is now *required* ... not just a fortuitous acident. Signed-off-by: David Brownell <email@example.com>