MEM: Enable multiple distributed generalized memories

This patch removes the assumption on having on single instance of
PhysicalMemory, and enables a distributed memory where the individual
memories in the system are each responsible for a single contiguous
address range.

All memories inherit from an AbstractMemory that encompasses the basic
behaviuor of a random access memory, and provides untimed access
methods. What was previously called PhysicalMemory is now
SimpleMemory, and a subclass of AbstractMemory. All future types of
memory controllers should inherit from AbstractMemory.

To enable e.g. the atomic CPU and RubyPort to access the now
distributed memory, the system has a wrapper class, called
PhysicalMemory that is aware of all the memories in the system and
their associated address ranges. This class thus acts as an
infinitely-fast bus and performs address decoding for these "shortcut"
accesses. Each memory can specify that it should not be part of the
global address map (used e.g. by the functional memories by some
testers). Moreover, each memory can be configured to be reported to
the OS configuration table, useful for populating ATAG structures, and
any potential ACPI tables.

Checkpointing support currently assumes that all memories have the
same size and organisation when creating and resuming from the
checkpoint. A future patch will enable a more flexible
re-organisation.

--HG--
rename : src/mem/PhysicalMemory.py => src/mem/AbstractMemory.py
rename : src/mem/PhysicalMemory.py => src/mem/SimpleMemory.py
rename : src/mem/physical.cc => src/mem/abstract_mem.cc
rename : src/mem/physical.hh => src/mem/abstract_mem.hh
rename : src/mem/physical.cc => src/mem/simple_mem.cc
rename : src/mem/physical.hh => src/mem/simple_mem.hh

4 files changed, 7 insertions, 10 deletions

diff --git a/src/arch/arm/ArmSystem.py b/src/arch/arm/ArmSystem.py
index e744c026c..f4aedaf98 100644
--- a/src/arch/arm/ArmSystem.py
+++ b/src/arch/arm/ArmSystem.py
@@ -56,8 +56,6 @@ class ArmSystem(System):
     # 0x0 Revision
     midr_regval = Param.UInt32(0x350fc000, "MIDR value")
     boot_loader = Param.String("", "File that contains the boot loader code if any")
-    boot_loader_mem = Param.PhysicalMemory(NULL,
-                          "Memory object that boot loader is to be loaded into")
     gic_cpu_addr = Param.Addr(0, "Addres of the GIC CPU interface")
     flags_addr = Param.Addr(0, "Address of the flags register for MP booting")
 
@@ -67,5 +65,3 @@ class LinuxArmSystem(ArmSystem):
     machine_type = Param.ArmMachineType('RealView_PBX',
         "Machine id from http://www.arm.linux.org.uk/developer/machines/")
     atags_addr = Param.Addr(0x100, "Address where default atags structure should be written")
-
-
diff --git a/src/arch/arm/linux/system.cc b/src/arch/arm/linux/system.cc
index 64bda4b4d..0d9e73a53 100644
--- a/src/arch/arm/linux/system.cc
+++ b/src/arch/arm/linux/system.cc
@@ -125,9 +125,14 @@ LinuxArmSystem::initState()
     ac->pagesize(8192);
     ac->rootdev(0);
 
+    AddrRangeList atagRanges = physmem.getConfAddrRanges();
+    if (atagRanges.size() != 1) {
+        fatal("Expected a single ATAG memory entry but got %d\n",
+              atagRanges.size());
+    }
     AtagMem *am = new AtagMem;
-    am->memSize(params()->physmem->size());
-    am->memStart(params()->physmem->start());
+    am->memSize(atagRanges.begin()->size());
+    am->memStart(atagRanges.begin()->start);
 
     AtagCmdline *ad = new AtagCmdline;
     ad->cmdline(params()->boot_osflags);
diff --git a/src/arch/arm/remote_gdb.hh b/src/arch/arm/remote_gdb.hh
index 9ff93b8e6..b75d921fb 100644
--- a/src/arch/arm/remote_gdb.hh
+++ b/src/arch/arm/remote_gdb.hh
@@ -37,7 +37,6 @@
 
 class System;
 class ThreadContext;
-class PhysicalMemory;
 
 namespace ArmISA
 {
diff --git a/src/arch/arm/system.cc b/src/arch/arm/system.cc
index 7fbabafcb..f6c4ad783 100644
--- a/src/arch/arm/system.cc
+++ b/src/arch/arm/system.cc
@@ -55,9 +55,6 @@ using namespace Linux;
 ArmSystem::ArmSystem(Params *p)
     : System(p), bootldr(NULL)
 {
-    if ((p->boot_loader == "") != (p->boot_loader_mem == NULL))
-        fatal("If boot_loader is specifed, memory to load it must be also.\n");
-
     if (p->boot_loader != "") {
         bootldr = createObjectFile(p->boot_loader);