kernel/memory: implement basic free-list heap

4 files changed, 24 insertions, 9 deletions

diff --git a/kapi/include/kapi/memory.hpp b/kapi/include/kapi/memory.hpp
index b234cde..9ef2cd7 100644
--- a/kapi/include/kapi/memory.hpp
+++ b/kapi/include/kapi/memory.hpp
@@ -78,8 +78,9 @@ namespace kapi::memory
   //!
   //! @param page The page to map.
   //! @param frame The frame to map the page into.
+  //! @param flags The flags to apply to this mapping.
   //! @return A pointer to the first byte of the mapped page.
-  auto map(page page, frame frame) -> std::byte *;
+  auto map(page page, frame frame, page_mapper::flags flags = page_mapper::flags::empty) -> std::byte *;
 
   //! @qualifier kernel-defined
   //! Unmap a page.
diff --git a/kapi/include/kapi/memory/address.hpp b/kapi/include/kapi/memory/address.hpp
index 39eb1ee..e5cf50b 100644
--- a/kapi/include/kapi/memory/address.hpp
+++ b/kapi/include/kapi/memory/address.hpp
@@ -55,6 +55,25 @@ namespace kapi::memory
       return std::bit_cast<std::byte *>(m_value);
     }
 
+    //! Create a new address n beyond this one.
+    //!
+    //! @param n The amount to increase the address by.
+    //! @return A new address, n further than this one.
+    constexpr auto operator+(std::uintptr_t n) const noexcept -> address
+    {
+      return address{m_value + n};
+    }
+
+    //! Increase this address by a given amount.
+    //!
+    //! @param n The amount to increase the address by.
+    //! @return A reference to this address.
+    constexpr auto operator+=(std::uintptr_t n) noexcept -> address &
+    {
+      m_value += n;
+      return *this;
+    }
+
     //! Shift this address n bits to the right.
     //!
     //! @param n The width of the shift.
diff --git a/kapi/include/kapi/memory/page.hpp b/kapi/include/kapi/memory/page.hpp
index 3846bd8..aa161ee 100644
--- a/kapi/include/kapi/memory/page.hpp
+++ b/kapi/include/kapi/memory/page.hpp
@@ -24,14 +24,6 @@ namespace kapi::memory
         : chunk{number}
     {}
 
-    //! @copydoc chunk::containing
-    //!
-    //! @note This factory shadows the base factory to aid in type deduction.
-    constexpr auto static containing(linear_address address) noexcept -> page
-    {
-      return page{chunk::containing(address)};
-    }
-
     //! Convert a base chunk into a page.
     //!
     //! This constructor allows for conversion from chunk<linear_address, PLATFORM_PAGE_SIZE> to a page for convenience.
diff --git a/kapi/include/kapi/memory/page_mapper.hpp b/kapi/include/kapi/memory/page_mapper.hpp
index 07eabcf..c6052e9 100644
--- a/kapi/include/kapi/memory/page_mapper.hpp
+++ b/kapi/include/kapi/memory/page_mapper.hpp
@@ -8,6 +8,8 @@
 
 #include <kstd/ext/bitfield_enum>
 
+#include <cstddef>
+#include <cstdint>
 #include <type_traits>
 
 namespace kapi::memory
@@ -30,6 +32,7 @@ namespace kapi::memory
       executable = 1 << 1,       //! The page contains executable instructions.
       uncached = 1 << 2,         //! The page contents must not be cached.
       supervisor_only = 1 << 3,  //! The page is only accessible in supervisor mode.
+      global = 1 << 4,           //! The page translation persists across context switches.
     };
 
     virtual ~page_mapper() = default;