Add iPod Nano 2G post-mortem memory dumper by Michael Sparmann

The files are downloaded from https://www.rockbox.org/tracker/task/11701

Change-Id: Ic6415f76207868661c231cb534cb179160eb60e0

utils/rbpms/librbpms.py

@@ -0,0 +1,55 @@
+#!/usr/bin/env python
+
+import sys
+import struct
+import usb
+
+
+class rbpms:
+  def __init__(self):
+    self.handle = usb.core.find(idVendor=0xffff, idProduct=0xa112)
+    if self.handle is None:
+        raise Exception("Could not find specified device")
+    self.handle.set_configuration()
+    print("Connected to Rockbox Post-Mortem Stub on iPod Nano 2G")
+
+
+  @staticmethod
+  def __myprint(data):
+    sys.stdout.write(data)
+    sys.stdout.flush()
+
+
+  def read(self, offset, size):
+    if offset & 15 != 0:
+      raise Exception("Unaligned data read!")
+
+    data = ""
+
+    while True:
+      blocklen = size
+      if blocklen == 0: break
+      if blocklen > 256 * 1024: blocklen = 256 * 1024
+      self.handle.write(4, struct.pack("<II", offset, blocklen), 0, 100)
+      block = struct.unpack("%ds" % blocklen, self.handle.read(0x83, blocklen, 0, 1000))[0]
+      offset += blocklen
+      data += block
+      size -= blocklen
+
+    return data
+
+
+  def download(self, offset, size, file):
+    self.__myprint("Downloading 0x%x bytes from 0x%8x to %s..." % (size, offset, file))
+    f = open(file, "wb")
+
+    while True:
+      blocklen = size
+      if blocklen == 0: break
+      if blocklen > 2048 * 1024: blocklen = 2048 * 1024
+      f.write(self.read(offset, blocklen))
+      offset += blocklen
+      size -= blocklen
+      self.__myprint(".")
+
+    self.__myprint(" done\n")

utils/rbpms/rbpms.py

@@ -0,0 +1,31 @@
+#!/usr/bin/env python
+import sys
+import librbpms
+
+
+def usage():
+  print ""
+  print "Please provide a command and (if needed) parameters as command line arguments"
+  print ""
+  print "Available commands:"
+  print ""
+  print "  download <address> <size> <file>"
+  print "    Downloads <size> bytes of data from the specified address on the device,"
+  print "    and stores it in the specified file."
+  print ""
+  print "All numbers are hexadecimal!"
+  exit(2)
+
+
+def parsecommand(dev, argv):
+  if len(argv) < 2: usage()
+
+  elif argv[1] == "download":
+    if len(argv) != 5: usage()
+    dev.download(int(argv[2], 16), int(argv[3], 16), argv[4])
+
+  else: usage()
+
+
+dev = librbpms.rbpms()
+parsecommand(dev, sys.argv)