2 files changed, 24 insertions, 8 deletions
diff --git a/arch/x86_64/src/memory/frame_allocator.cpp b/arch/x86_64/src/memory/frame_allocator.cpp
index 01dcc88..70276ae 100644
--- a/arch/x86_64/src/memory/frame_allocator.cpp
+++ b/arch/x86_64/src/memory/frame_allocator.cpp
@@ -4,8 +4,6 @@
 
 namespace teachos::arch::memory
 {
-  uint64_t PAGE_SIZE;
-
   physical_frame::physical_frame(std::size_t frame_number)
       : frame_number(frame_number)
   {
@@ -17,7 +15,7 @@ namespace teachos::arch::memory
     return physical_frame{address / PAGE_FRAME_SIZE};
   }
 
-  auto physical_frame::start_address() const -> uint64_t { return frame_number * PAGE_SIZE; }
+  auto physical_frame::start_address() const -> uint64_t { return frame_number * PAGE_FRAME_SIZE; }
 
   memory_area_iterator::memory_area_iterator(memory_area * p)
       : ptr(p)
@@ -39,6 +37,21 @@ namespace teachos::arch::memory
     return *this;
   }
 
+  area_frame_allocator::area_frame_allocator(std::size_t kernel_start, std::size_t kernel_end,
+                                             std::size_t multiboot_start, std::size_t multiboot_end,
+                                             memory_area * memory_areas, uint8_t area_count)
+      : next_free_frame(0)
+      , current_area(std::nullopt)
+      , area_begin(memory_areas)
+      , area_end(memory_areas + area_count)
+      , kernel_start(physical_frame::containing_address(kernel_start))
+      , kernel_end(physical_frame::containing_address(kernel_end))
+      , multiboot_start(physical_frame::containing_address(multiboot_start))
+      , multiboot_end(physical_frame::containing_address(multiboot_end))
+  {
+    choose_next_area();
+  }
+
   auto area_frame_allocator::choose_next_area() -> void
   {
     current_area = std::nullopt;
diff --git a/arch/x86_64/src/memory/paging.cpp b/arch/x86_64/src/memory/paging.cpp
index 2f78da8..a07b2c0 100644
--- a/arch/x86_64/src/memory/paging.cpp
+++ b/arch/x86_64/src/memory/paging.cpp
@@ -42,12 +42,9 @@ namespace teachos::arch::memory
 
   auto page_table::zero_entries() -> void
   {
-    auto begin = &entries[0];
-    auto end = &entries[PAGE_TABLE_ENTRY_COUNT];
-
-    for (auto entry = begin; entry < end; ++entry)
+    for (size_t i = 0; i < sizeof(entries) / sizeof(entries[0]); ++i)
     {
-      entry->set_unused();
+      entries[i].set_unused();
     }
   }
 
@@ -75,4 +72,10 @@ namespace teachos::arch::memory
 
     return std::nullopt;
   }
+
+  entry & page_table::operator[](std::size_t index)
+  {
+    arch::exception_handling::assert(index < PAGE_TABLE_ENTRY_COUNT, "[Page Table] index out of bounds");
+    return entries[index];
+  }
 }  // namespace teachos::arch::memory