tests/vfs_fat_ramdisk: Allow to override sector size.

tests/extmod/vfs_fat_ramdisk.py

@@ -8,23 +8,28 @@ except AttributeError:
 
 
 class RAMFS:
+
+    SEC_SIZE = 512
+
     def __init__(self, blocks):
-        self.data = bytearray(blocks * 512)
+        self.data = bytearray(blocks * self.SEC_SIZE)
 
     def readblocks(self, n, buf):
         #print("readblocks(%s, %x(%d))" % (n, id(buf), len(buf)))
         for i in range(len(buf)):
-            buf[i] = self.data[n*512+i]
+            buf[i] = self.data[n * self.SEC_SIZE + i]
 
     def writeblocks(self, n, buf):
         #print("writeblocks(%s, %x)" % (n, id(buf)))
         for i in range(len(buf)):
-            self.data[n*512+i] = buf[i]
+            self.data[n * self.SEC_SIZE + i] = buf[i]
 
     def ioctl(self, op, arg):
         #print("ioctl(%d, %r)" % (op, arg))
         if op == 4:  # BP_IOCTL_SEC_COUNT
-            return len(self.data) // 512
+            return len(self.data) // self.SEC_SIZE
+        if op == 5:  # BP_IOCTL_SEC_SIZE
+            return self.SEC_SIZE
 
 
 bdev = RAMFS(48)