dcc_parser: Fix offset type descriptor parse issue

Write indicator only works for address type descriptor. Move the
checker into address type case. This fixes an issue in offset type
descriptor if len2 is above 64. Check empty indicator 0xdededede
before parsing the descriptor.

Change-Id: I49acf1a86f92965584b16348cb14cc453e1a3669

dcc_parser/dcc_parser.py

@@ -99,6 +99,8 @@ def read_config(config_pt):
         on_zero_link_len = -1
         #word size
         track_len = 4
+        #empty SRAM is filled with 0xdededede
+        empty_ind = 0xdededede
 
     if options.config_offset is not None:
         config_pt.seek(int(options.config_offset, 16), 1)
@@ -121,12 +123,15 @@ def read_config(config_pt):
         descriptor = val & (0x3 << 30)
 	read_write_ind = val & (0x1 << 28)
 
-	if read_write_ind == dcc_write_ind:
+        if val == empty_ind:
             config_pt.seek(8, 1)
         elif descriptor == address_descriptor:
-            base = ((val & 0x0FFFFFFF) << 4)
-            offset = 0
-            length = 1
+            if read_write_ind == dcc_write_ind:
+                config_pt.seek(8, 1)
+            else:
+                base = ((val & 0x0FFFFFFF) << 4)
+                offset = 0
+                length = 1
         elif descriptor == link_descriptor:
             for i in range(0, 2):
                 offset = offset + (val & 0xFF) * 4 + (length - 1) * track_len