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-rw-r--r--arch/x86_64/include/arch/memory/allocator/physical_frame.hpp2
-rw-r--r--arch/x86_64/include/arch/memory/paging/page_mapper.hpp2
-rw-r--r--arch/x86_64/include/arch/memory/paging/page_table.hpp22
-rw-r--r--arch/x86_64/include/arch/memory/paging/virtual_page.hpp2
-rw-r--r--arch/x86_64/src/kernel/main.cpp27
-rw-r--r--arch/x86_64/src/memory/paging/page_mapper.cpp14
-rw-r--r--arch/x86_64/src/memory/paging/page_table.cpp16
7 files changed, 61 insertions, 24 deletions
diff --git a/arch/x86_64/include/arch/memory/allocator/physical_frame.hpp b/arch/x86_64/include/arch/memory/allocator/physical_frame.hpp
index e013e0d..e33c77a 100644
--- a/arch/x86_64/include/arch/memory/allocator/physical_frame.hpp
+++ b/arch/x86_64/include/arch/memory/allocator/physical_frame.hpp
@@ -27,7 +27,7 @@ namespace teachos::arch::memory::allocator
* @param physical_address Physical address we want to get the corresponding physical frame for.
* @return Frame the given address is contained in.
*/
- static auto containing_address(std::size_t physical_address) -> physical_frame;
+ auto static containing_address(std::size_t physical_address) -> physical_frame;
/**
* @brief Evaluates the start address of the physical frame.
diff --git a/arch/x86_64/include/arch/memory/paging/page_mapper.hpp b/arch/x86_64/include/arch/memory/paging/page_mapper.hpp
index 0f226e2..a8cca4c 100644
--- a/arch/x86_64/include/arch/memory/paging/page_mapper.hpp
+++ b/arch/x86_64/include/arch/memory/paging/page_mapper.hpp
@@ -145,7 +145,9 @@ namespace teachos::arch::memory::paging
exception_handling::assert(level1_frame.has_value(),
"[Page Mapper] Attempted to unmap page, which has not been mapped previously");
level1_entry.set_unused();
+ // TODO: Flush the translation lookaside buffer to clear the entry from cache as well. (mov cr3, cr3)
// TODO: Deallocate and unmap level 1, 2, 3 page table entry if this was the last page in them.
+ // TODO: Fix deallocate because it is not yet implemented.
allocator.deallocate_frame(level1_frame.value());
}
} // namespace teachos::arch::memory::paging
diff --git a/arch/x86_64/include/arch/memory/paging/page_table.hpp b/arch/x86_64/include/arch/memory/paging/page_table.hpp
index 91ce81c..3a31dc5 100644
--- a/arch/x86_64/include/arch/memory/paging/page_table.hpp
+++ b/arch/x86_64/include/arch/memory/paging/page_table.hpp
@@ -5,10 +5,7 @@
namespace teachos::arch::memory::paging
{
- namespace
- {
- constexpr std::size_t PAGE_TABLE_ENTRY_COUNT = 512U; ///< Default entry count of a page table in x86_84 is 512.
- }
+ constexpr std::size_t PAGE_TABLE_ENTRY_COUNT = 512U; ///< Default entry count of a page table in x86_84 is 512.
/**
* @brief Forward delcaration of the page_table, because it should only be accessible over the handle, the actual
@@ -66,13 +63,26 @@ namespace teachos::arch::memory::paging
*/
auto operator[](std::size_t index) const -> entry;
+ /**
+ * @brief Decrements the page table handle level enum by one, is defined so we can use it as a replacement for an
+ * int index in a range based for loop. Will halt execution if called with page_table_handle::LEVEL1, because there
+ * is no level below. Has to be defined as either a friend function or inline header method, because we define an
+ * operator of another type. In this instance friend function was choosen, because the struct itself also requires
+ * the operator, but declaring before the struct is not possible, because the enum is in the struct. This is
+ * inpossible because the struct requires the operator declared before itself to work, and the operator requires the
+ * struct declared before itself to work. Furthermore this allows the defintion of the method to be done in the cpp,
+ * avoiding includes in the header file.
+ *
+ * @param value Value we want to decrement on
+ * @return level New level value decrement by one, meaning the level is also decrement by one Level4 --> Level3, ...
+ */
+ friend auto operator--(level value, int) -> level;
+
private:
page_table * handle; ///< Handle to underlying page table, can never be null (invariant ensured by constructor)
level handle_level; ///< Level page table is currently on, depends on how often next_level was
///< called successfully.
};
-
- auto operator--(page_table_handle::level & level, int) -> page_table_handle::level;
} // namespace teachos::arch::memory::paging
#endif // TEACHOS_ARCH_X86_64_MEMORY_PAGING_PAGE_TABLE_HPP
diff --git a/arch/x86_64/include/arch/memory/paging/virtual_page.hpp b/arch/x86_64/include/arch/memory/paging/virtual_page.hpp
index ca11b3c..79801ee 100644
--- a/arch/x86_64/include/arch/memory/paging/virtual_page.hpp
+++ b/arch/x86_64/include/arch/memory/paging/virtual_page.hpp
@@ -28,7 +28,7 @@ namespace teachos::arch::memory::paging
* @param virtual_address Virtual address we want to get the corresponding virtual page for.
* @return Frame the given address is contained in.
*/
- static auto containing_address(std::size_t virtual_address) -> virtual_page;
+ auto static containing_address(std::size_t virtual_address) -> virtual_page;
/**
* @brief Evaluates the start address of the virtual page.
diff --git a/arch/x86_64/src/kernel/main.cpp b/arch/x86_64/src/kernel/main.cpp
index 8e5aa05..3e25d2d 100644
--- a/arch/x86_64/src/kernel/main.cpp
+++ b/arch/x86_64/src/kernel/main.cpp
@@ -10,6 +10,7 @@
namespace teachos::arch::kernel
{
+
auto main() -> void
{
video::vga::text::clear();
@@ -19,6 +20,25 @@ namespace teachos::arch::kernel
auto memory_information = memory::multiboot::read_multiboot2();
memory::allocator::area_frame_allocator allocator(memory_information);
+ 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 page = memory::paging::virtual_page::containing_address(address);
+ auto frame = allocator.allocate_frame();
+ exception_handling::assert(frame.has_value(), "[Main] Out of memory exception");
+ auto optional_frame = memory::paging::translate_page(page);
+ memory::paging::map_page_to_frame(allocator, page, frame.value(), 0U);
+ 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);
+
+ memory::paging::unmap_page(allocator, page);
+ video::vga::text::write("Unapped physical page: ", 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;
do
@@ -26,12 +46,9 @@ namespace teachos::arch::kernel
last_allocated = allocated;
allocated = allocator.allocate_frame();
} while (allocated);
- video::vga::text::write("Allocated Frames", video::vga::text::common_attributes::green_on_black);
+ video::vga::text::newline();
+ video::vga::text::write("Allocated Frames: ", video::vga::text::common_attributes::green_on_black);
video::vga::text::write_number(last_allocated.value().frame_number,
video::vga::text::common_attributes::green_on_black);
- memory::paging::map_page_to_frame(allocator, memory::paging::virtual_page{0U}, last_allocated.value(), 0U);
- memory::paging::map_next_free_page_to_frame(allocator, memory::paging::virtual_page{0U}, 0U);
- memory::paging::identity_map(allocator, last_allocated.value(), 0U);
- memory::paging::unmap_page(allocator, memory::paging::virtual_page{0U});
}
} // namespace teachos::arch::kernel
diff --git a/arch/x86_64/src/memory/paging/page_mapper.cpp b/arch/x86_64/src/memory/paging/page_mapper.cpp
index b8f6b89..75b17ff 100644
--- a/arch/x86_64/src/memory/paging/page_mapper.cpp
+++ b/arch/x86_64/src/memory/paging/page_mapper.cpp
@@ -14,15 +14,23 @@ namespace teachos::arch::memory::paging
return page_table_handle{active_page, page_table_handle::LEVEL4};
}
+ auto subtract_level(page_table_handle::level level) -> page_table_handle::level
+ {
+ exception_handling::assert(level != page_table_handle::LEVEL1,
+ "[Page table] Attemptd to decrement enum to value outside of range");
+ auto value = static_cast<std::underlying_type<page_table_handle::level>::type>(level);
+ return static_cast<page_table_handle::level>(--value);
+ }
+
auto translate_page(virtual_page page) -> std::optional<allocator::physical_frame>
{
auto current_handle = create_or_get();
- for (auto level = page_table_handle::LEVEL4; level != page_table_handle::LEVEL1; level--)
+ for (auto level = page_table_handle::LEVEL4; level != page_table_handle::LEVEL1; level = subtract_level(level))
{
auto next_handle = current_handle.next_table(page.get_level_index(level));
- // If the next table method failed then it is highly likely that it was a huge page and we therefore have to parse
- // the table differently. Therefore, we attempt to parse it using the method required by huge pages.
+ // If the next table method failed then it is highly likely that it was a huge page and we therefore have to
+ // parse the table differently. Therefore, we attempt to parse it using the method required by huge pages.
if (!next_handle)
{
return translate_huge_page(page);
diff --git a/arch/x86_64/src/memory/paging/page_table.cpp b/arch/x86_64/src/memory/paging/page_table.cpp
index 852bbd5..9c9ca76 100644
--- a/arch/x86_64/src/memory/paging/page_table.cpp
+++ b/arch/x86_64/src/memory/paging/page_table.cpp
@@ -47,14 +47,6 @@ namespace teachos::arch::memory::paging
///< virtual addresses for the level 1 page table.
};
- auto operator--(page_table_handle::level level, int) -> page_table_handle::level
- {
- exception_handling::assert(level != page_table_handle::LEVEL1,
- "[Page table] Attemptd to decrement enum to value outside of range");
- auto value = static_cast<std::underlying_type<page_table_handle::level>::type>(level);
- return static_cast<page_table_handle::level>(--value);
- }
-
auto page_table::zero_entries() -> void
{
constexpr size_t entry_amount = sizeof(entries) / sizeof(entries[0]);
@@ -117,4 +109,12 @@ namespace teachos::arch::memory::paging
}
auto page_table_handle::operator[](std::size_t index) const -> entry { return handle->operator[](index); }
+
+ auto operator--(page_table_handle::level value, int) -> page_table_handle::level
+ {
+ exception_handling::assert(value != page_table_handle::LEVEL1,
+ "[Page table] Attemptd to decrement enum to value outside of range");
+ auto new_value = static_cast<std::underlying_type<page_table_handle::level>::type>(value);
+ return static_cast<page_table_handle::level>(--new_value);
+ }
} // namespace teachos::arch::memory::paging
generated by cgit v1.2.3 (git 2.25.1) at 2026-04-19 18:27:03 +0000