From b9ece9bbcb376f4e36fe13ccb261fcfff8da8e7b Mon Sep 17 00:00:00 2001
From: Eryn Wells <eryn@erynwells.me>
Date: Fri, 25 Mar 2016 01:21:37 -0400
Subject: [PATCH] Add MemoryManager class

This will be the top-level class for the memory manager subsystem.
Copy in some code from kmain()
---
 src/Memory.cc  | 37 +++++++++++++++++++++++++++++++++++++
 src/Memory.hh  | 30 ++++++++++++++++++++++++++++++
 src/SConscript |  1 +
 3 files changed, 68 insertions(+)
 create mode 100644 src/Memory.cc
 create mode 100644 src/Memory.hh

diff --git a/src/Memory.cc b/src/Memory.cc
new file mode 100644
index 0000000..66342a6
--- /dev/null
+++ b/src/Memory.cc
@@ -0,0 +1,37 @@
+/* Memory.cc
+ * vim: set tw=80:
+ * Eryn Wells <eryn@erynwells.me>
+ */
+/**
+ * Top-level classes for managing system memory.
+ */
+
+#include "Memory.hh"
+
+namespace kernel {
+
+/*
+ * Public
+ */
+
+void
+MemoryManager::initialize(Console& console)
+{
+    initializeGDT();
+    console.printString("GDT loaded\n");
+}
+
+/*
+ * Private
+ */
+
+void
+MemoryManager::initializeGDT()
+{
+    mGDT.setNullDescriptor(0);
+    mGDT.setDescriptor(1, x86::GDT::DescriptorSpec::kernelSegment(0, 0xFFFFFFFF, x86::GDT::Type::CodeEXR));
+    mGDT.setDescriptor(2, x86::GDT::DescriptorSpec::kernelSegment(0, 0xFFFFFFFF, x86::GDT::Type::DataRW));
+    mGDT.load();
+}
+    
+} /* namespace kernel */
diff --git a/src/Memory.hh b/src/Memory.hh
new file mode 100644
index 0000000..257c17a
--- /dev/null
+++ b/src/Memory.hh
@@ -0,0 +1,30 @@
+/* Memory.hh
+ * vim: set tw=80:
+ * Eryn Wells <eryn@erynwells.me>
+ */
+/**
+ * Declaration of top-level classes for managing system memory.
+ */
+
+#ifndef __MEMORY_HH__
+#define __MEMORY_HH__
+
+#include "Console.hh"
+#include "Descriptors.hh"
+
+
+namespace kernel {
+
+struct MemoryManager
+{
+    void initialize(Console& console);
+
+private:
+    x86::GDT mGDT;
+
+    void initializeGDT();
+};
+    
+} /* namespace kernel */
+
+#endif /* __MEMORY_HH__ */
diff --git a/src/SConscript b/src/SConscript
index cdf8a01..d3af908 100644
--- a/src/SConscript
+++ b/src/SConscript
@@ -15,6 +15,7 @@ files = [
     'Descriptors.cc',
     'Interrupts.cc',
     'Kernel.cc',
+    'Memory.cc',
     'Multiboot.cc',
     'PIC.cc',
     'cxa.cc',