Redesign fs_dev, raw_dev, introducing device_partition and switch_fs.

In theory, one could mount an encrypted FAT partition itself coming from a disk image, etc.

fusee/fusee-primary/src/hwinit.h

@@ -35,4 +35,5 @@ void display_enable_backlight(bool on);
 
 void cluster_enable_cpu0(u64 entry, u32 ns_disable);
 
+void mc_enable_ahb_redirect();
 #endif