1 files changed, 57 insertions, 0 deletions
diff --git a/kernel/src/test_support/page_mapper.cpp b/kernel/src/test_support/page_mapper.cpp
new file mode 100644
index 0000000..a026ec3
--- /dev/null
+++ b/kernel/src/test_support/page_mapper.cpp
@@ -0,0 +1,57 @@
+#include "kernel/tests/page_mapper.hpp"
+
+#include "kapi/memory.hpp"
+
+#include <kstd/units>
+
+#include <cstddef>
+#include <format>
+#include <stdexcept>
+
+namespace kernel::tests
+{
+
+  page_mapper::page_mapper(kstd::units::bytes memory_size)
+      : memory{memory_size}
+  {}
+
+  auto page_mapper::map(kapi::memory::page page, kapi::memory::frame frame, flags) -> std::byte *
+  {
+    page_mappings.insert({page.number(), frame});
+
+    auto page_address = page.start_address();
+
+    if (page_address >= kapi::memory::mmio_base)
+    {
+      throw std::invalid_argument{"MMIO mapping not yet supported in testing!"};
+    }
+    else if (page_address >= kapi::memory::higher_half_direct_map_base)
+    {
+      auto offset = frame.number() * kapi::memory::frame::size;
+      return memory.ram_base() + offset;
+    }
+
+    return nullptr;
+  }
+
+  auto page_mapper::unmap(kapi::memory::page page) -> void
+  {
+    if (!try_unmap(page))
+    {
+      auto error = std::format("Page {} was never mapped!", page.number());
+      throw std::invalid_argument{error};
+    }
+  }
+
+  auto page_mapper::try_unmap(kapi::memory::page page) noexcept -> bool
+  {
+    if (page_mappings.contains(page.number()))
+    {
+      page_mappings.erase(page.number());
+      return true;
+    }
+
+    return false;
+  }
+
+}  // namespace kernel::tests
+\ No newline at end of file