A FAT12 dump script that got left behing in some old master branch (was used in #1793)

radio/util/fat12decode.py

@@ -0,0 +1,52 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+
+"""
+  To dump FAT and prepare input for this program, one can use command like this:
+    # dd if=/dev/sde skip=1 count=1 | hexdump -v -e '/1 "%02X "' | tr -d ' '
+
+  Stock FAT is this:
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
+  
+"""
+
+import sys
+import os
+
+def displayCluster(cluster, hexfat):
+  decfat = int(hexfat, 16)
+
+  next = ""
+  if decfat == 0:
+    next = "-"
+  elif decfat == 1:
+    next = "invalid"
+  elif decfat <= 0xfef : # 002-fef: cluster in use
+    next = "next %03d" % decfat
+  elif decfat <= 0xff6:  # reserved,
+    next = "reserved (0x%03x)" % decfat
+  elif decfat == 0xff7: #bad cluster
+    next = "bad"
+  elif decfat <= 0xfff: # cluster in use, the last one in this file
+    next = "last in this file (0x%03x)" % decfat
+
+  print "cluster %03d: %s" % (cluster, next)
+
+
+data = sys.argv[1]
+
+cluster = 0
+while len(data) > 0:
+  twofats = data[0:6]
+  fat1 = twofats[3] + twofats[0:2]
+  fat2 = twofats[4:6] + twofats[2]
+  # print "fat1 %s, fat2 %s" % (fat1, fat2)
+  data = data[len(twofats):]
+
+  displayCluster(cluster, fat1)
+  displayCluster(cluster+1, fat2)
+
+  # print "cluster %03d: next %03d" % (cluster, int(fat1, 16))
+  # print "cluster %03d: next %03d" % (cluster+1, int(fat2, 16))
+  cluster = cluster + 2