Buttons lower half: Undefine __KERNEL__ before including board.h to suppress bad included; fix some configuratin issues

drivers/input/Kconfig

@@ -349,7 +349,9 @@ config BUTTONS_LOWER
 		   NUM_BUTTONS, and
 		4. The board.h header file must not include any other
 		   header files that are not accessibble in this context
-		   (such as those in arch/<arch>/src/<chip>).
+		   (such as those in arch/<arch>/src/<chip>) UNLESS those
+		   inclusions are conditioned on __KERNEL__.  button_lower.c
+		   will undefine __KERNEL__ before included board.h.
 
 		If your board does not meet these requirements, then the
 		board_lower.c file can still be copied to your your

drivers/input/button_lower.c

@@ -47,6 +47,8 @@
 #include <nuttx/input/buttons.h>
 
 #include <arch/irq.h>
+
+#undef __KERNEL__
 #include <arch/board/board.h>
 
 #if CONFIG_BUTTONS_LOWER

fs/nxffs/README.txt

@@ -175,6 +175,6 @@ Things to Do
   done.  That garbarge collection should search for valid blocks that no
   longer contain valid data.  It should pre-erase them, put them in
   a good but empty state... all ready for file system re-organization.
-
-
+- And worse, when NXFSS reorganization the FLASH a power cycle can
+  damage the file system content if it happens at the wrong time.