Mem: Separate the host and guest views of memory backing store

This patch moves all the memory backing store operations from the
independent memory controllers to the global physical memory. The main
reason for this patch is to allow address striping in a future set of
patches, but at this point it already provides some useful
functionality in that it is now possible to change the number of
memory controllers and their address mapping in combination with
checkpointing. Thus, the host and guest view of the memory backing
store are now completely separate.

With this patch, the individual memory controllers are far simpler as
all responsibility for serializing/unserializing is moved to the
physical memory. Currently, the functionality is more or less moved
from AbstractMemory to PhysicalMemory without any major
changes. However, in a future patch the physical memory will also
resolve any ranges that are interleaved and properly assign the
backing store to the memory controllers, and keep the host memory as a
single contigous chunk per address range.

Functionality for future extensions which involve CPU virtualization
also enable the host to get pointers to the backing store.

util/cpt_upgrader.py

@@ -61,11 +61,8 @@ import ConfigParser
 import sys, os
 import os.path as osp
 
-def from_0(cpt):
-    pass
-
 # An example of a translator
-def from_1(cpt):
+def from_0(cpt):
     if cpt.get('root','isa') == 'arm':
         for sec in cpt.sections():
             import re
@@ -77,6 +74,37 @@ def from_1(cpt):
                 #mr.insert(26,0)
                 cpt.set(sec, 'miscRegs', ' '.join(str(x) for x in mr))
 
+# The backing store supporting the memories in the system has changed
+# in that it is now stored globally per address range. As a result the
+# actual storage is separate from the memory controllers themselves.
+def from_1(cpt):
+    for sec in cpt.sections():
+        import re
+        # Search for a physical memory
+        if re.search('.*sys.*\.physmem$', sec):
+            # Add the number of stores attribute to the global physmem
+            cpt.set(sec, 'nbr_of_stores', '1')
+
+            # Get the filename and size as this is moving to the
+            # specific backing store
+            mem_filename = cpt.get(sec, 'filename')
+            mem_size = cpt.get(sec, '_size')
+            cpt.remove_option(sec, 'filename')
+            cpt.remove_option(sec, '_size')
+
+            # Get the name so that we can create the new section
+            system_name = str(sec).split('.')[0]
+            section_name = system_name + '.physmem.store0'
+            cpt.add_section(section_name)
+            cpt.set(section_name, 'store_id', '0')
+            cpt.set(section_name, 'range_size', mem_size)
+            cpt.set(section_name, 'filename', mem_filename)
+        elif re.search('.*sys.*\.\w*mem$', sec):
+            # Due to the lack of information about a start address,
+            # this migration only works if there is a single memory in
+            # the system, thus starting at 0
+            raise ValueError("more than one memory detected (" + sec + ")")
+
 migrations = []
 migrations.append(from_0)
 migrations.append(from_1)