implemented microSD mount/unmount functions

deck/fs.py

@@ -5,7 +5,7 @@ import os
 
 MCU_STORAGE = False
 try:
-  import storage
+  import storage, sdcardio, board
   MCU_STORAGE = True
 except:
   pass
@@ -18,6 +18,28 @@ def lock_rootfs():
   if MCU_STORAGE:
     storage.remount("/", readonly=True)
 
+def mount_sd(path='/sd', readonly=False):
+  sd_ok = True
+  if MCU_STORAGE:
+    try:
+      sdcard = sdcardio.SDCard(board.SPI(), board.SDCARD_CS)
+      vfs = storage.VfsFat(sdcard)
+      storage.mount(vfs, path, readonly=readonly)
+      sd_ok = True
+    except:
+      sd_ok = False
+  return sd_ok
+
+def umount_sd(path='/sd'):
+  sd_ok = True
+  if MCU_STORAGE:
+    try:
+      storage.umount(path)
+      sd_ok = True
+    except:
+      sd_ok = False
+  return sd_ok
+
 # TODO: switch to buffered copying to avoid RAM overflow
 def copy(p1, p2):
   with open(p1, 'rb') as f1: