create temporary page implementation

3 files changed, 67 insertions, 27 deletions

diff --git a/arch/x86_64/src/kernel/main.cpp b/arch/x86_64/src/kernel/main.cpp
index 5c55213..a27631f 100644
--- a/arch/x86_64/src/kernel/main.cpp
+++ b/arch/x86_64/src/kernel/main.cpp
@@ -4,6 +4,7 @@
 #include "arch/memory/allocator/area_frame_allocator.hpp"
 #include "arch/memory/multiboot/reader.hpp"
 #include "arch/memory/paging/page_mapper.hpp"
+#include "arch/memory/paging/temporary_page.hpp"
 #include "arch/video/vga/text.hpp"
 
 #include <algorithm>
@@ -22,22 +23,26 @@ namespace teachos::arch::kernel
     size_t address = 42 * memory::paging::PAGE_TABLE_ENTRY_COUNT * memory::paging::PAGE_TABLE_ENTRY_COUNT *
                      memory::allocator::PAGE_FRAME_SIZE;  // 42th P3 entry
     auto const page = memory::paging::virtual_page::containing_address(address);
-    memory::paging::map_next_free_page_to_frame(allocator, page, 0U);
-    auto optional_frame = memory::paging::translate_page(page);
-    video::vga::text::newline();
-    video::vga::text::write("Mapped physical frame: ", video::vga::text::common_attributes::green_on_black);
-    video::vga::text::write_number(optional_frame.value().frame_number,
-                                   video::vga::text::common_attributes::green_on_black);
-    video::vga::text::write(" to virtual page: ", video::vga::text::common_attributes::green_on_black);
-    video::vga::text::write_number(page.page_number, video::vga::text::common_attributes::green_on_black);
 
-    memory::paging::unmap_page(allocator, page);
-    video::vga::text::newline();
-    video::vga::text::write("Unapped virtual page from physical frame: ",
-                            video::vga::text::common_attributes::green_on_black);
-    optional_frame = memory::paging::translate_page(page);
-    exception_handling::assert(!optional_frame.has_value(), "[Main] Ummapping failed");
-    video::vga::text::write_number(page.page_number, video::vga::text::common_attributes::green_on_black);
+    memory::paging::temporary_page temp_page{page, allocator};
+    temp_page.zero_entries();
+
+    // memory::paging::map_next_free_page_to_frame(allocator, page, 0U);
+    // auto optional_frame = memory::paging::translate_page(page);
+    // video::vga::text::newline();
+    // video::vga::text::write("Mapped physical frame: ", video::vga::text::common_attributes::green_on_black);
+    // video::vga::text::write_number(optional_frame.value().frame_number,
+    //                                video::vga::text::common_attributes::green_on_black);
+    // video::vga::text::write(" to virtual page: ", video::vga::text::common_attributes::green_on_black);
+    // video::vga::text::write_number(page.page_number, video::vga::text::common_attributes::green_on_black);
+
+    // memory::paging::unmap_page(allocator, page);
+    // video::vga::text::newline();
+    // video::vga::text::write("Unapped virtual page from physical frame: ",
+    //                         video::vga::text::common_attributes::green_on_black);
+    // optional_frame = memory::paging::translate_page(page);
+    // exception_handling::assert(!optional_frame.has_value(), "[Main] Ummapping failed");
+    // video::vga::text::write_number(page.page_number, video::vga::text::common_attributes::green_on_black);
 
     auto last_allocated = allocator.allocate_frame();
     auto allocated = last_allocated;
diff --git a/arch/x86_64/src/memory/paging/page_table.cpp b/arch/x86_64/src/memory/paging/page_table.cpp
index 3ad1d54..3c9942a 100644
--- a/arch/x86_64/src/memory/paging/page_table.cpp
+++ b/arch/x86_64/src/memory/paging/page_table.cpp
@@ -88,33 +88,33 @@ namespace teachos::arch::memory::paging
     return std::nullopt;
   }
 
-  page_table_handle::page_table_handle(page_table * handle, page_table_handle::level handle_level)
-      : handle(handle)
-      , handle_level(handle_level)
+  page_table_handle::page_table_handle(page_table * table, page_table_handle::level table_level)
+      : table(table)
+      , table_level(table_level)
   {
-    exception_handling::assert(handle != nullptr,
-                               "[Page Table] Attempted to pass nullptr as handle to page table handle method");
+    exception_handling::assert(table != nullptr,
+                               "[Page Table] Attempted to pass nullptr as table to page table table method");
   }
 
-  auto page_table_handle::zero_entries() -> void { handle->zero_entries(); }
+  auto page_table_handle::zero_entries() -> void { table->zero_entries(); }
 
-  auto page_table_handle::is_empty() const -> bool { return handle->is_empty(); }
+  auto page_table_handle::is_empty() const -> bool { return table->is_empty(); }
 
   auto page_table_handle::next_table(std::size_t table_index) -> std::optional<page_table_handle>
   {
-    exception_handling::assert(handle_level != page_table_handle::LEVEL1,
+    exception_handling::assert(table_level != page_table_handle::LEVEL1,
                                "[Page Table] Attempted to call next_table on level 1 page table");
-    auto const next_table = handle->next_table(table_index);
+    auto const next_table = table->next_table(table_index);
     if (next_table.has_value())
     {
-      return page_table_handle{next_table.value(), --handle_level};
+      return page_table_handle{next_table.value(), --table_level};
     }
     return std::nullopt;
   }
 
-  auto page_table_handle::get_level() const -> page_table_handle::level { return handle_level; }
+  auto page_table_handle::get_level() const -> page_table_handle::level { return table_level; }
 
-  auto page_table_handle::operator[](std::size_t index) -> entry & { return handle->operator[](index); }
+  auto page_table_handle::operator[](std::size_t index) -> entry & { return table->operator[](index); }
 
   auto operator--(page_table_handle::level & value) -> page_table_handle::level &
   {
diff --git a/arch/x86_64/src/memory/paging/temporary_page.cpp b/arch/x86_64/src/memory/paging/temporary_page.cpp
new file mode 100644
index 0000000..433f0ce
--- /dev/null
+++ b/arch/x86_64/src/memory/paging/temporary_page.cpp
@@ -0,0 +1,35 @@
+#include "arch/memory/paging/temporary_page.hpp"
+
+#include "arch/memory/paging/page_entry.hpp"
+#include "arch/memory/paging/page_mapper.hpp"
+
+namespace teachos::arch::memory::paging
+{
+  auto temporary_page::map_to_frame(allocator::physical_frame frame) -> virtual_address
+  {
+    exception_handling::assert(!translate_page(page).has_value(), "[Temporary page] Page is already mapped");
+
+    map_page_to_frame(allocator, page, frame, entry::WRITABLE);
+    return page.start_address();
+  }
+
+  auto temporary_page::unmap() -> void { unmap_page(allocator, page); }
+
+  auto temporary_page::map_table_frame(allocator::physical_frame frame) -> page_table_handle
+  {
+    page_table_handle handle{reinterpret_cast<page_table *>(map_to_frame(frame)), page_table_handle::LEVEL1};
+    return handle;
+  }
+
+  auto temporary_page::zero_entries() -> void
+  {
+    auto frame = allocator.allocate_frame();
+    exception_handling::assert(!frame.has_value(), "[Temporary Page] Tiny allocator could not allocate a frame");
+
+    page_table_handle handle = map_table_frame(frame.value());
+    handle.zero_entries();
+    handle[511].set_entry(frame.value(), entry::PRESENT | entry::WRITABLE);
+
+    unmap();
+  }
+}  // namespace teachos::arch::memory::paging
\ No newline at end of file