implement page table members

3 files changed, 32 insertions, 4 deletions

diff --git a/arch/x86_64/include/arch/memory/frame_allocator.hpp b/arch/x86_64/include/arch/memory/frame_allocator.hpp
index 69c108c..3d1f826 100644
--- a/arch/x86_64/include/arch/memory/frame_allocator.hpp
+++ b/arch/x86_64/include/arch/memory/frame_allocator.hpp
@@ -32,9 +32,9 @@ namespace teachos::arch::memory
     static auto containing_address(std::size_t address) -> physical_frame;
 
     /**
-     * @brief  TODO
+     * @brief Evaluates the start address of the physical frame
      *
-     * @return uint64_t
+     * @return start address of the physical frame
      */
     auto start_address() const -> uint64_t;
 
diff --git a/arch/x86_64/include/arch/memory/paging.hpp b/arch/x86_64/include/arch/memory/paging.hpp
index 1870c28..43f13e0 100644
--- a/arch/x86_64/include/arch/memory/paging.hpp
+++ b/arch/x86_64/include/arch/memory/paging.hpp
@@ -89,11 +89,28 @@ namespace teachos::arch::memory
   };
 
   /**
-   * @brief TODO
-   *
+   * @brief A Page table containing 512 entries
    */
   struct page_table
   {
+    /**
+     * @brief Set every entry of the page to unused
+     */
+    auto zero_entries() -> void;
+
+    /**
+     * @brief Index operator overload to access specific entries directy
+     *
+     * @param index
+     * @return The address of the accessed entry
+     */
+    entry & operator[](size_t index)
+    {
+      arch::exception_handling::assert(index < PAGE_TABLE_ENTRY_COUNT, "[Page Table] index out of bounds");
+      return entries[index];
+    }
+
+  private:
     entry entries[PAGE_TABLE_ENTRY_COUNT];
   };
 }  // namespace teachos::arch::memory
diff --git a/arch/x86_64/src/memory/paging.cpp b/arch/x86_64/src/memory/paging.cpp
index 90c4199..58a2b99 100644
--- a/arch/x86_64/src/memory/paging.cpp
+++ b/arch/x86_64/src/memory/paging.cpp
@@ -40,4 +40,15 @@ namespace teachos::arch::memory
 
   auto entry::contains_flags(std::bitset<64U> b) const -> bool { return (flags & b) == b; }
 
+  auto page_table::zero_entries() -> void
+  {
+    auto begin = &entries[0];
+    auto end = &entries[PAGE_TABLE_ENTRY_COUNT];
+
+    for (auto entry = begin; entry < end; ++entry)
+    {
+      entry->set_unused();
+    }
+  }
+
 }  // namespace teachos::arch::memory