fs.mitm: Implement bis protection

common/defaults/system_settings.ini

@@ -20,6 +20,12 @@
 ; for restoration on new game launch. 1 = always save toggles,
 ; 0 = only save toggles if toggle file exists.
 ; dmnt_always_save_cheat_toggles = u8!0x0
+; Enable writing to BIS partitions for HBL.
+; This is probably undesirable for normal usage.
+; enable_hbl_bis_write = u8!0x0
+; Enable reading the CAL0 partition for HBL.
+; This is probably undesirable for normal usage.
+; enable_hbl_cal_read = u8!0x0
 ; Controls whether fs.mitm should redirect save files
 ; to directories on the sd card.
 ; 0 = Do not redirect, 1 = Redirect.