kapi: move independent implementation to kernel

2 files changed, 69 insertions, 0 deletions

diff --git a/kernel/CMakeLists.txt b/kernel/CMakeLists.txt
index 9868eb9..ab77467 100644
--- a/kernel/CMakeLists.txt
+++ b/kernel/CMakeLists.txt
@@ -1,5 +1,6 @@
 add_library("kernel_objs" OBJECT
     # Platform-independent KAPI implementation
+    "kapi/acpi.cpp"
     "kapi/boot_modules.cpp"
     "kapi/cio.cpp"
     "kapi/cpu.cpp"
diff --git a/kernel/kapi/acpi.cpp b/kernel/kapi/acpi.cpp
new file mode 100644
index 0000000..aa0066d
--- /dev/null
+++ b/kernel/kapi/acpi.cpp
@@ -0,0 +1,68 @@
+#include "kapi/acpi.hpp"
+
+#include "kapi/memory.hpp"
+
+#include <kstd/units>
+
+#include <algorithm>
+#include <bit>
+#include <cstddef>
+#include <cstdint>
+#include <span>
+#include <string_view>
+
+namespace kapi::acpi
+{
+
+  namespace
+  {
+    constexpr auto validate_checksum(std::span<std::byte const> data) -> bool
+    {
+      auto sum = std::ranges::fold_left(
+          data, std::uint8_t{}, [](std::uint8_t acc, auto byte) { return static_cast<std::uint8_t>(byte) + acc; });
+      return sum == 0;
+    }
+  }  // namespace
+
+  auto root_system_description_pointer::oem_id() const noexcept -> std::string_view
+  {
+    return {m_oem_id.data(), m_oem_id.size()};
+  }
+
+  auto root_system_description_pointer::revision() const noexcept -> std::uint8_t
+  {
+    return m_revision;
+  }
+
+  auto root_system_description_pointer::signature() const noexcept -> std::string_view
+  {
+    return {m_signature.data(), m_signature.size()};
+  }
+
+  auto root_system_description_pointer::table_address() const noexcept -> memory::physical_address
+  {
+    auto raw = std::bit_cast<std::uint32_t>(m_rsdt_address);
+    return memory::physical_address{static_cast<std::uintptr_t>(raw)};
+  }
+
+  auto root_system_description_pointer::validate() const noexcept -> bool
+  {
+    return validate_checksum({reinterpret_cast<std::byte const *>(this), sizeof(root_system_description_pointer)});
+  }
+
+  auto extended_system_description_pointer::length() const noexcept -> kstd::units::bytes
+  {
+    return kstd::units::bytes{m_length};
+  }
+
+  auto extended_system_description_pointer::table_address() const noexcept -> memory::physical_address
+  {
+    return memory::physical_address{std::bit_cast<std::uintptr_t>(m_xsdt_address)};
+  }
+
+  auto extended_system_description_pointer::validate() const noexcept -> bool
+  {
+    return validate_checksum({reinterpret_cast<std::byte const *>(this), m_length});
+  }
+
+};  // namespace kapi::acpi