From a099a6dc101f022f02bb3107dd5b5f6fc10c2ea1 Mon Sep 17 00:00:00 2001
From: Nathan Giddings <nathan@nathan-laptop.localdomain>
Date: Thu, 10 Dec 2020 01:55:37 -0600
Subject: [PATCH] Started abstract memory manager class

---
 src/memorymanager.hpp | 50 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 src/memorymanager.hpp

diff --git a/src/memorymanager.hpp b/src/memorymanager.hpp
new file mode 100644
index 0000000..96d9c39
--- /dev/null
+++ b/src/memorymanager.hpp
@@ -0,0 +1,50 @@
+#ifndef MEMORYMANAGER_H
+#define MEMORYMANAGER_H
+
+#include "systypes.h"
+
+class MemoryManager
+{
+public:
+
+    /**
+     * Allocates space for a new top-level page table, and initializes it to
+     * point only to the kernel's page tables.
+     * 
+     * @returns the physical address of the new top-level page table
+     */
+    virtual physaddr_t createAddressSpace() = 0;
+
+    /**
+     * Loads the given top-level page table(s).
+     *
+     * @param table the top-level page table to load
+     */
+    virtual void loadAddressSpace(physaddr_t table) = 0;
+
+    /**
+     * Maps a single page to a single frame. Allocates a new page table if one
+     * does not exist for that frame.
+     * 
+     * @param page the virtual address of the page to map
+     * @param frame the physical address of the frame to map to
+     * @param flags flags to apply to the entry
+     * 
+     * @returns zero upon success, nonzero on failure
+     */
+    virtual int mapPage(void* page, physaddr_t frame, int flags) = 0;
+
+    /**
+     * Deletes the page table entry for the specified page. Does not deallocate
+     * redundant page tables or modify higher level tables; these are cleaned up
+     * after the owning process ends.
+     *
+     * @param page the virtual address of the page to unmap
+     *
+     * @returns zero upon success, nonzero on failure
+     */
+    virtual int unmapPage(void* page) = 0;
+
+};
+
+#endif
\ No newline at end of file