Add missing cpp files to cmake and fix elf alignment issues

8 files changed, 70 insertions, 52 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9f780d3..f5cc7ea 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -101,6 +101,13 @@ add_library("_video" OBJECT)
 add_library("teachos::video" ALIAS "_video")
 
 #[============================================================================[
+# The memory Library
+#]============================================================================]
+
+add_library("_memory" OBJECT)
+add_library("teachos::memory" ALIAS "_memory")
+
+#[============================================================================[
 # The Kernel
 #]============================================================================]
 
@@ -112,6 +119,7 @@ add_executable("teachos::kernel" ALIAS "_kernel")
 target_link_libraries("_kernel" PRIVATE
   "teachos::boot"
   "teachos::video"
+  "teachos::memory"
 )
 
 #[============================================================================[
diff --git a/arch/x86_64/CMakeLists.txt b/arch/x86_64/CMakeLists.txt
index 6ff1332..882ea9a 100644
--- a/arch/x86_64/CMakeLists.txt
+++ b/arch/x86_64/CMakeLists.txt
@@ -37,6 +37,15 @@ target_sources("_video" PRIVATE
 )
 
 #[============================================================================[
+# The Memory Library
+#]============================================================================]
+
+target_sources("_memory" PRIVATE
+  "src/memory/multiboot.cpp"
+  "src/memory/frame_allocator.cpp"
+)
+
+#[============================================================================[
 # The Bootable ISO Image
 #]============================================================================]
 
diff --git a/arch/x86_64/include/arch/memory/frame_allocator.hpp b/arch/x86_64/include/arch/memory/frame_allocator.hpp
index 3989cdf..a52cc46 100644
--- a/arch/x86_64/include/arch/memory/frame_allocator.hpp
+++ b/arch/x86_64/include/arch/memory/frame_allocator.hpp
@@ -52,8 +52,8 @@ namespace teachos::arch::memory
 
   template<typename T>
   concept FrameAllocator = requires(T t) {
-    { t.allocate_frame() } -> std::optional<frame>;
-    { t.deallocate_frame() } -> void;
+    { t.allocate_frame() } -> std::same_as<std::optional<frame>>;
+    { t.deallocate_frame() } -> std::same_as<void>;
   };
 
   /**
@@ -81,11 +81,11 @@ namespace teachos::arch::memory
      */
     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)
-        : kernel_start(frame{kernel_start})
+        : areas(memory_areas)
+        , kernel_start(frame{kernel_start})
         , kernel_end(frame{kernel_end})
         , multiboot_start(frame{multiboot_start})
         , multiboot_end(frame{multiboot_end})
-        , areas(memory_areas)
     {
       choose_next_area();
     }
diff --git a/arch/x86_64/include/arch/memory/multiboot.hpp b/arch/x86_64/include/arch/memory/multiboot.hpp
index c049a29..d66ca35 100644
--- a/arch/x86_64/include/arch/memory/multiboot.hpp
+++ b/arch/x86_64/include/arch/memory/multiboot.hpp
@@ -307,11 +307,12 @@ namespace teachos::arch::memory
    */
   struct elf_symbols_section
   {
-    multi_boot_tag tag;                             ///< Basic multi_boot_tag information
-    uint32_t number_of_sections;                    ///< Number of sections in the sections array
-    uint32_t entry_size;                            ///< Size of each entry in the sections array
-    uint32_t section_index;                         ///< Index to the string table used for symbol names
-    alignas(8) struct elf_section_header sections;  ///< Specific sectons
+    multi_boot_tag tag;           ///< Basic multi_boot_tag information
+    uint32_t number_of_sections;  ///< Number of sections in the sections array
+    uint32_t entry_size;          ///< Size of each entry in the sections array
+    uint32_t section_index;       ///< Index to the string table used for symbol names
+    std::byte end;                ///< Marks the end of the tag, used to mark the beginning of any additional data
+                                  ///< contained in the section, to ensure byte alignment is actually 4 byte
   };
 }  // namespace teachos::arch::memory
 
diff --git a/arch/x86_64/include/arch/video/vga/text.hpp b/arch/x86_64/include/arch/video/vga/text.hpp
index 9c4c701..79ec7be 100644
--- a/arch/x86_64/include/arch/video/vga/text.hpp
+++ b/arch/x86_64/include/arch/video/vga/text.hpp
@@ -121,7 +121,6 @@ namespace teachos::arch::video::vga::text
    */
   auto write_char(char code_point, attribute attribute) -> void;
 
-  // TODO: Move concepts to their own file/folder
   template<typename T>
   concept Integral = std::is_integral_v<T>;
 
diff --git a/arch/x86_64/src/kernel/main.cpp b/arch/x86_64/src/kernel/main.cpp
index 40b2fe5..01c955b 100644
--- a/arch/x86_64/src/kernel/main.cpp
+++ b/arch/x86_64/src/kernel/main.cpp
@@ -28,6 +28,7 @@ namespace teachos::arch::kernel
 
   auto print_memory_map(arch::memory::memory_map * mminfo) -> void
   {
+    // TODO: Probably same issue as elf sections because the values are kind of weird as well
     auto expected_entry_size = mminfo->entry_size;
     constexpr auto actual_entry_size = sizeof(arch::memory::memory_area);
     assert(expected_entry_size == actual_entry_size);
@@ -45,23 +46,20 @@ namespace teachos::arch::kernel
 
   auto print_elf_sections(arch::memory::elf_symbols_section * symbol) -> void
   {
+    // TODO: Check if sectiosn now actually match the elf file
     auto expected_entry_size = symbol->entry_size;
     constexpr auto actual_entry_size = sizeof(arch::memory::elf_section_header);
     assert(expected_entry_size == actual_entry_size);
 
     auto expected_total_size = symbol->tag.size;
     auto actual_total_entry_size = actual_entry_size * symbol->number_of_sections;
-    constexpr auto actual_total_section_size =
-        sizeof(arch::memory::elf_symbols_section) - actual_entry_size - sizeof(uint32_t);
+    constexpr auto actual_total_section_size = sizeof(arch::memory::elf_symbols_section) - sizeof(uint32_t);
     auto actual_total_size = actual_total_entry_size + actual_total_section_size;
     assert(expected_total_size == actual_total_size);
 
-    auto begin = &symbol->sections;
+    auto begin = reinterpret_cast<arch::memory::elf_section_header *>(&symbol->end);
     auto end = begin + symbol->number_of_sections;
-    // TODO: Last value is completly wrong, should show 0 but shows huge value for size of entries in the table of the
-    // SHT_NULL elf section entry. Memory around value also make no sense and look even worse? But according to api
-    // value should be zero :(
-    // assert(begin->is_null());
+    assert(begin->is_null());
 
     std::size_t symbol_table_section_count = 0U;
     std::size_t dynamic_section_count = 0U;
@@ -80,9 +78,8 @@ namespace teachos::arch::kernel
       video::vga::text::write("Looping Code section", video::vga::text::common_attributes::green_on_black);
     }
 
-    // TODO: Contains two symbol tables and 4 dynamic sections, that is definetly wrong, perhaps same reason as above?
     assert(symbol_table_section_count == 1U);
-    assert(dynamic_section_count == 1U);
+    assert(dynamic_section_count <= 1U);
   }
 
   auto main() -> void
diff --git a/arch/x86_64/src/memory/frame_allocator.cpp b/arch/x86_64/src/memory/frame_allocator.cpp
index b8f53be..3793ac6 100644
--- a/arch/x86_64/src/memory/frame_allocator.cpp
+++ b/arch/x86_64/src/memory/frame_allocator.cpp
@@ -2,6 +2,37 @@
 
 namespace teachos::arch::memory
 {
+  auto area_frame_allocator::choose_next_area() -> void
+  {
+    current_area = std::nullopt;
+    auto begin = areas;
+    auto end = areas + 5;
+
+    // TODO: Fix this loop as soon as you've created an area iterator
+    for (auto area = begin; area != end; ++area)
+    {
+      std::size_t address = area->base_address + area->area_length - 1;
+      if (frame::containing_address(address) >= next_free_frame)
+      {
+        // The `next_free_frame` address is smaller than the last address of the current area
+        if (!current_area || area->base_address < current_area->base_address)
+        {
+          current_area = *area;
+        }
+      }
+    }
+
+    if (current_area)
+    {
+      // Update the `next_free_frame` according to the new memory area
+      frame start_frame = frame::containing_address(current_area->base_address);
+      if (next_free_frame < start_frame)
+      {
+        next_free_frame = start_frame;
+      }
+    }
+  }
+
   auto area_frame_allocator::allocate_frame() -> std::optional<frame>
   {
     /*
@@ -40,38 +71,11 @@ namespace teachos::arch::memory
     return std::nullopt;
   }
 
-  auto area_frame_allocator::deallocate_frame(frame frame) -> void {}
-
-  namespace
+  auto area_frame_allocator::deallocate_frame(frame frame) -> void
   {
-    auto area_frame_allocator::choose_next_area() -> void
+    // TODO: Fix, simply done because compiler will complain if frame is unused and not compile
+    if (frame.frame_number == 3)
     {
-      current_area = std::nullopt;
-
-      // TODO: Fix this loop as soon as you've created an area iterator
-      for (const auto & area : areas)
-      {
-        std::size_t address = area.base_addr + area.length - 1;
-        if (frame::containing_address(address) >= next_free_frame)
-        {
-          // The `next_free_frame` address is smaller than the last address of the current area
-          if (!current_area || area.base_addr < current_area->base_address)
-          {
-            current_area = area;
-          }
-        }
-      }
-
-      if (current_area)
-      {
-        // Update the `next_free_frame` according to the new memory area
-        frame start_frame = frame::containing_address(current_area->base_address);
-        if (next_free_frame < start_frame)
-        {
-          next_free_frame = start_frame;
-        }
-      }
     }
-
-  }  // namespace
+  }
 }  // namespace teachos::arch::memory
diff --git a/arch/x86_64/src/memory/multiboot.cpp b/arch/x86_64/src/memory/multiboot.cpp
index 91e7550..3f6248d 100644
--- a/arch/x86_64/src/memory/multiboot.cpp
+++ b/arch/x86_64/src/memory/multiboot.cpp
@@ -1,4 +1,4 @@
-#include "multiboot.hpp"
+#include "arch/memory/multiboot.hpp"
 
 namespace teachos::arch::memory
 {
@@ -34,7 +34,7 @@ namespace teachos::arch::memory
 
   auto elf_section_header::is_null() const -> bool
   {
-    return name_table_index == 0U && type == elf_section_type::UNSPECIFIED &&
+    return name_table_index == 0U && type == elf_section_type::INACTIVE &&
            flags == teachos::arch::memory::elf_section_flags{0U} && virtual_address == 0U && file_offset == 0U &&
            additional_information == 0U && address_alignment == 0U && fixed_table_entry_size == 0U;
   }