12 files changed, 565 insertions, 239 deletions

diff --git a/arch/x86_64/kapi/platform.cpp b/arch/x86_64/kapi/platform.cpp
index 4ee35c7..fb27329 100644
--- a/arch/x86_64/kapi/platform.cpp
+++ b/arch/x86_64/kapi/platform.cpp
@@ -8,57 +8,54 @@
 #include <kstd/memory>
 #include <kstd/print>
 
-#include <cstddef>
+#include <ranges>
 #include <utility>
 
 namespace kapi::platform
 {
+  namespace
+  {
+    constexpr auto candidate_flags = acpi::processor_local_apic::flags::processor_enabled  //
+                                     | acpi::processor_local_apic::flags::online_capable;
+  }
 
   auto discover_cpu_topology(kapi::devices::bus & bus) -> bool
   {
     auto static const core_major = kapi::devices::allocate_major_number();
     auto static const interrupt_controller_major = kapi::devices::allocate_major_number();
 
-    auto madt = kapi::acpi::get_table("APIC");
+    auto madt = kapi::acpi::get_table<acpi::madt_table_signature>();
     if (!madt)
     {
       kstd::println("[x86_64:PLT] Failed to find ACPI APIC table");
       return false;
     }
 
-    auto real_madt = static_cast<acpi::madt_header const *>(madt.get());
-    auto current = reinterpret_cast<std::byte const *>(madt.get()) + sizeof(kapi::acpi::madt_header);
-    auto end = reinterpret_cast<std::byte const *>(madt.get()) + madt->length();
-
     auto bsp_found = false;
     auto core_count = 0uz;
+    auto local_apic_address = madt->local_interrupt_controller_address();
 
-    while (current < end)
+    auto lapic_entries = *madt | std::views::filter([](auto const & entry) {
+      return entry.type() == acpi::multiple_apic_description_table_entry::types::processor_local_apic;
+    }) | std::views::transform([](auto const & entry) {
+      return static_cast<acpi::processor_local_apic const &>(entry);
+    }) | std::views::filter([](auto const & entry) {
+      return static_cast<bool>(entry.active_flags() & candidate_flags);
+    });
+
+    for (auto const & apic : lapic_entries)
     {
-      auto const * sub_table = reinterpret_cast<kapi::acpi::madt_subtable_header const *>(current);
-      if (sub_table->type() == 0)
+      auto is_bsp = !bsp_found;
+      bsp_found = true;
+      auto instance = kstd::make_unique<arch::devices::local_apic>(interrupt_controller_major, core_count,
+                                                                   apic.apic_id(), local_apic_address, is_bsp);
+      if (kapi::platform::cpu_detected(bus, core_major, core_count, apic.processor_id(), is_bsp, std::move(instance)))
       {
-        auto const * local_apic = reinterpret_cast<kapi::acpi::madt_local_apic const *>(sub_table);
-        if (local_apic->flags() & 0b11)
-        {
-          auto is_bsp = !bsp_found;
-          bsp_found = true;
-          auto lapic = kstd::make_unique<arch::devices::local_apic>(
-              interrupt_controller_major, core_count, local_apic->apic_id(),
-              real_madt->local_interrupt_controller_address(), is_bsp);
-          if (kapi::platform::cpu_detected(bus, core_major, core_count, local_apic->processor_id(), is_bsp,
-                                           std::move(lapic)))
-          {
-            ++core_count;
-          }
-        }
+        ++core_count;
       }
-
-      current += sub_table->length();
     }
 
     kstd::println("[x86_64:PLT] Found {} CPU cores", core_count);
-
     return core_count > 0;
   }
 
diff --git a/kapi/include/kapi/acpi.hpp b/kapi/include/kapi/acpi.hpp
index 75b6c48..5323fee 100644
--- a/kapi/include/kapi/acpi.hpp
+++ b/kapi/include/kapi/acpi.hpp
@@ -1,14 +1,15 @@
 #ifndef TEACHOS_KAPI_ACPI_HPP
 #define TEACHOS_KAPI_ACPI_HPP
 
-#include "kapi/memory.hpp"
+#include "kapi/acpi/multiple_apic_description_table.hpp"  // IWYU pragma: export
+#include "kapi/acpi/pointers.hpp"                         // IWYU pragma: export
+#include "kapi/acpi/system_description_table_header.hpp"  // IWYU pragma: export
+#include "kapi/acpi/table_type.hpp"
 
 #include <kstd/memory>
 #include <kstd/units>
 
-#include <array>
 #include <cstddef>
-#include <cstdint>
 #include <span>
 #include <string_view>
 
@@ -18,91 +19,6 @@ namespace kapi::acpi
   //! @addtogroup kapi-acpi-kernel-defined
   //! @{
 
-  struct [[gnu::packed]] root_system_description_pointer
-  {
-    [[nodiscard]] auto oem_id() const noexcept -> std::string_view;
-    [[nodiscard]] auto revision() const noexcept -> std::uint8_t;
-    [[nodiscard]] auto signature() const noexcept -> std::string_view;
-    [[nodiscard]] auto table_address() const noexcept -> memory::physical_address;
-    [[nodiscard]] auto validate() const noexcept -> bool;
-
-  private:
-    std::array<char, 8> m_signature;
-    [[maybe_unused]] std::uint8_t m_checksum;
-    std::array<char, 6> m_oem_id;
-    std::uint8_t m_revision;
-    std::array<std::byte, 4> m_rsdt_address;
-  };
-
-  struct [[gnu::packed]] extended_system_description_pointer : root_system_description_pointer
-  {
-    [[nodiscard]] auto length() const noexcept -> kstd::units::bytes;
-    [[nodiscard]] auto table_address() const noexcept -> memory::physical_address;
-    [[nodiscard]] auto validate() const noexcept -> bool;
-
-  private:
-    std::uint32_t m_length;
-    std::array<std::byte, 8> m_xsdt_address;
-    [[maybe_unused]] std::uint8_t m_extended_checksum;
-    [[maybe_unused]] std::array<std::byte, 3> m_reserved;
-  };
-
-  struct [[gnu::packed]] system_description_table_header
-  {
-    [[nodiscard]] auto checksum() const noexcept -> std::uint8_t;
-    [[nodiscard]] auto creator_revision() const noexcept -> std::uint32_t;
-    [[nodiscard]] auto creator_id() const noexcept -> std::uint32_t;
-    [[nodiscard]] auto length() const noexcept -> kstd::units::bytes;
-    [[nodiscard]] auto oem_id() const noexcept -> std::string_view;
-    [[nodiscard]] auto oem_revision() const noexcept -> std::uint32_t;
-    [[nodiscard]] auto oem_table_id() const noexcept -> std::string_view;
-    [[nodiscard]] auto revision() const noexcept -> std::uint8_t;
-    [[nodiscard]] auto signature() const noexcept -> std::string_view;
-
-  private:
-    std::array<char, 4> m_signature;
-    std::uint32_t m_length;
-    std::uint8_t m_revision;
-    std::uint8_t m_checksum;
-    std::array<char, 6> m_oem_id;
-    std::array<char, 8> m_oem_table_id;
-    std::uint32_t m_oem_revision;
-    std::uint32_t m_creator_id;
-    std::uint32_t m_creator_revision;
-  };
-
-  struct [[gnu::packed]] madt_header : system_description_table_header
-  {
-    [[nodiscard]] auto local_interrupt_controller_address() const noexcept -> memory::physical_address;
-    [[nodiscard]] auto flags() const noexcept -> std::uint32_t;
-
-  private:
-    std::uint32_t m_local_interrupt_controller_address;
-    std::uint32_t m_flags;
-  };
-
-  struct [[gnu::packed]] madt_subtable_header
-  {
-    [[nodiscard]] auto type() const noexcept -> std::uint8_t;
-    [[nodiscard]] auto length() const noexcept -> std::size_t;
-
-  private:
-    std::uint8_t m_type;
-    std::uint8_t m_length;
-  };
-
-  struct [[gnu::packed]] madt_local_apic : madt_subtable_header
-  {
-    [[nodiscard]] auto apic_id() const noexcept -> std::uint8_t;
-    [[nodiscard]] auto flags() const noexcept -> std::uint32_t;
-    [[nodiscard]] auto processor_id() const noexcept -> std::uint32_t;
-
-  private:
-    std::uint8_t m_processor_id;
-    std::uint8_t m_apic_id;
-    std::uint32_t m_flags;
-  };
-
   //! Initialize the ACPI subsystem and discover the available tables.
   //!
   //! @return true iff. a valid system description tabled was found, false otherwise.
@@ -114,17 +30,30 @@ namespace kapi::acpi
   //! @return true iff. the checksum is valid, false otherwise.
   auto validate_checksum(std::span<std::byte const> data) -> bool;
 
-  //! Get an ACPI table by its signature.
+  //! Get a pointer to an ACPI table by its signature.
   //!
   //! @param signature The signature of the table to get.
   //! @return A pointer to the table if found, nullptr otherwise.
   auto get_table(std::string_view signature) -> kstd::observer_ptr<system_description_table_header const>;
 
+  //! Get a type-cast pointer to an ACPI table by its signature.
+  //!
+  //! @tparam Signature The signature of the table to get
+  //! @return A pointer to the table if found, nullptr otherwise.
+  template<char const * Signature>
+  auto get_table() -> kstd::observer_ptr<table_type_t<Signature> const>
+  {
+    return kstd::make_observer(static_cast<table_type_t<Signature> const *>(get_table(Signature).get()));
+  }
+
   //! @}
 
   //! @addtogroup kapi-acpi-platform-defined
   //! @{
 
+  //! Retrieve the RSDP or XSDP for this system.
+  //!
+  //! @return a pointer to either the RSDP or XSDP data structure, or @p nullptr if neither is present.
   auto get_root_pointer() -> kstd::observer_ptr<root_system_description_pointer const>;
 
   //! @}
diff --git a/kapi/include/kapi/acpi/multiple_apic_description_table.hpp b/kapi/include/kapi/acpi/multiple_apic_description_table.hpp
new file mode 100644
index 0000000..33acac9
--- /dev/null
+++ b/kapi/include/kapi/acpi/multiple_apic_description_table.hpp
@@ -0,0 +1,104 @@
+#ifndef TEACHOS_KAPI_ACPI_MUTIPLE_APIC_DESCRIPTION_TABLE_HEADER_HPP
+#define TEACHOS_KAPI_ACPI_MUTIPLE_APIC_DESCRIPTION_TABLE_HEADER_HPP
+
+// IWYU pragma: private, include "kapi/acpi.hpp"
+
+#include "kapi/acpi/system_description_table_header.hpp"
+#include "kapi/acpi/table_iterator.hpp"
+#include "kapi/acpi/table_type.hpp"
+#include "kapi/memory.hpp"
+
+#include <kstd/ext/bitfield_enum>
+#include <kstd/units>
+
+#include <cstddef>
+#include <cstdint>
+#include <type_traits>
+
+namespace kapi::acpi
+{
+
+  //! @addtogroup kapi-acpi-kernel-defined
+  //! @{
+
+  struct [[gnu::packed]] multiple_apic_description_table_entry
+  {
+    enum struct types : std::uint8_t
+    {
+      processor_local_apic,
+      io_apic,
+      io_apic_interrupt_source_override,
+      io_apic_nmi_source,
+      local_apic_nmi_interrupts,
+      local_apic_address_override,
+      processor_local_x2_apic,
+    };
+
+    [[nodiscard]] auto type() const noexcept -> types;
+    [[nodiscard]] auto length() const noexcept -> std::size_t;
+
+  private:
+    std::uint8_t m_type;
+    std::uint8_t m_length;
+  };
+
+  //! The common header for all
+  struct [[gnu::packed]] multiple_apic_description_table : system_description_table_header
+  {
+    using iterator = table_iterator<multiple_apic_description_table_entry const>;
+    using const_iterator = iterator;
+
+    [[nodiscard]] auto local_interrupt_controller_address() const noexcept -> memory::physical_address;
+    [[nodiscard]] auto flags() const noexcept -> std::uint32_t;
+
+    [[nodiscard]] auto begin() const noexcept -> iterator;
+    [[nodiscard]] auto cbegin() const noexcept -> iterator;
+    [[nodiscard]] auto end() const noexcept -> iterator;
+    [[nodiscard]] auto cend() const noexcept -> iterator;
+
+  private:
+    std::uint32_t m_local_interrupt_controller_address;
+    std::uint32_t m_flags;
+  };
+
+  struct [[gnu::packed]] processor_local_apic : multiple_apic_description_table_entry
+  {
+    enum struct flags : std::uint32_t
+    {
+      processor_enabled = 1,
+      online_capable = 2,
+    };
+
+    [[nodiscard]] auto apic_id() const noexcept -> std::uint8_t;
+    [[nodiscard]] auto active_flags() const noexcept -> flags;
+    [[nodiscard]] auto processor_id() const noexcept -> std::uint32_t;
+
+  private:
+    std::uint8_t m_processor_id;
+    std::uint8_t m_apic_id;
+    std::uint32_t m_flags;
+  };
+
+  //! @}
+
+  //! @addtogroup kapi-acpi
+  //! @{
+
+  constexpr char const madt_table_signature[] = "APIC";  // NOLINT
+
+  template<>
+  struct table_type<madt_table_signature>
+  {
+    using type = multiple_apic_description_table;
+  };
+
+  //! @}
+
+}  // namespace kapi::acpi
+
+template<>
+struct kstd::ext::is_bitfield_enum<kapi::acpi::processor_local_apic::flags> : std::true_type
+{
+};
+
+#endif
diff --git a/kapi/include/kapi/acpi/pointers.hpp b/kapi/include/kapi/acpi/pointers.hpp
new file mode 100644
index 0000000..2b88720
--- /dev/null
+++ b/kapi/include/kapi/acpi/pointers.hpp
@@ -0,0 +1,79 @@
+#ifndef TEACHOS_KAPI_ACPI_POINTERS_HPP
+#define TEACHOS_KAPI_ACPI_POINTERS_HPP
+
+// IWYU pragma: private, include "kapi/acpi.hpp"
+
+#include "kapi/memory.hpp"
+
+#include <kstd/units>
+
+#include <array>
+#include <cstddef>
+#include <cstdint>
+#include <string_view>
+
+namespace kapi::acpi
+{
+
+  //! @addtogroup kapi-acpi-kernel-defined
+  //! @{
+
+  //! A pointer to the Root System Description Table.
+  struct [[gnu::packed]] root_system_description_pointer
+  {
+    //! Get the ID of the OEM, usually a vendor name.
+    [[nodiscard]] auto oem_id() const noexcept -> std::string_view;
+
+    //! Get the revision of the ACPI Root System Description Table.
+    //!
+    //! @note Revisions greater or equal to two indicate that the system uses the Extended System Description Table, and
+    //! as such that table should be use to query information.
+    [[nodiscard]] auto revision() const noexcept -> std::uint8_t;
+
+    //! Get the signature of this pointer.
+    //!
+    //! A valid RSDP must always carry the signature "RSD PTR ".
+    [[nodiscard]] auto signature() const noexcept -> std::string_view;
+
+    //! Get the physical address of the pointed-to Root System Description Table.
+    [[nodiscard]] auto table_address() const noexcept -> memory::physical_address;
+
+    //! Validate the checksum of this RSDP.
+    //!
+    //! @return @p true iff. the checksum of this RSDP is valid, @p false otherwise.
+    [[nodiscard]] auto validate() const noexcept -> bool;
+
+  private:
+    std::array<char, 8> m_signature;
+    [[maybe_unused]] std::uint8_t m_checksum;
+    std::array<char, 6> m_oem_id;
+    std::uint8_t m_revision;
+    std::array<std::byte, 4> m_rsdt_address;
+  };
+
+  //! A pointer to the Extended System Description Table.
+  struct [[gnu::packed]] extended_system_description_pointer : root_system_description_pointer
+  {
+    //! Get the length of the data contained in this pointer.
+    [[nodiscard]] auto length() const noexcept -> kstd::units::bytes;
+
+    //! Get the address of the pointed-to Extended System Description Table.
+    [[nodiscard]] auto table_address() const noexcept -> memory::physical_address;
+
+    //! Validate the checksum of this XSDP.
+    //!
+    //! @return @p true iff. the checksum of this RSDP is valid, @p false otherwise.
+    [[nodiscard]] auto validate() const noexcept -> bool;
+
+  private:
+    std::uint32_t m_length;
+    std::array<std::byte, 8> m_xsdt_address;
+    [[maybe_unused]] std::uint8_t m_extended_checksum;
+    [[maybe_unused]] std::array<std::byte, 3> m_reserved;
+  };
+
+  //! @}
+
+}  // namespace kapi::acpi
+
+#endif
diff --git a/kapi/include/kapi/acpi/system_description_table_header.hpp b/kapi/include/kapi/acpi/system_description_table_header.hpp
new file mode 100644
index 0000000..b336ea1
--- /dev/null
+++ b/kapi/include/kapi/acpi/system_description_table_header.hpp
@@ -0,0 +1,76 @@
+#ifndef TEACHOS_KAPI_ACPI_SYSTEM_DESCRIPTION_TABLE_HEADER_HPP
+#define TEACHOS_KAPI_ACPI_SYSTEM_DESCRIPTION_TABLE_HEADER_HPP
+
+// IWYU pragma: private, include "kapi/acpi.hpp"
+
+#include "kapi/acpi/table_type.hpp"
+
+#include <kstd/units>
+
+#include <array>
+#include <cstdint>
+#include <string_view>
+
+namespace kapi::acpi
+{
+
+  //! @addtogroup kapi-acpi-kernel-defined
+  //! @{
+
+  //! The common header of all System Description Tables.
+  struct [[gnu::packed]] system_description_table_header
+  {
+    //! Get the revision of the utility used to create this table.
+    [[nodiscard]] auto creator_revision() const noexcept -> std::uint32_t;
+
+    //! Get the vendor ID of the utility used to create this table.
+    [[nodiscard]] auto creator_id() const noexcept -> std::uint32_t;
+
+    //! Get the length of the entire table, including this header.
+    [[nodiscard]] auto length() const noexcept -> kstd::units::bytes;
+
+    //! Get the ID of the OEM.
+    [[nodiscard]] auto oem_id() const noexcept -> std::string_view;
+
+    //! Get the OEMs revision number of this table.
+    [[nodiscard]] auto oem_revision() const noexcept -> std::uint32_t;
+
+    //! Get the OEMs ID of this table.
+    [[nodiscard]] auto oem_table_id() const noexcept -> std::string_view;
+
+    //! Get the revision number of the structure of this table.
+    [[nodiscard]] auto revision() const noexcept -> std::uint8_t;
+
+    //! Get the signature of this table.
+    [[nodiscard]] auto signature() const noexcept -> std::string_view;
+
+  private:
+    std::array<char, 4> m_signature;
+    std::uint32_t m_length;
+    std::uint8_t m_revision;
+    [[maybe_unused]] std::uint8_t m_checksum;
+    std::array<char, 6> m_oem_id;
+    std::array<char, 8> m_oem_table_id;
+    std::uint32_t m_oem_revision;
+    std::uint32_t m_creator_id;
+    std::uint32_t m_creator_revision;
+  };
+
+  //! @}
+  //
+  //! @addtogroup kapi-acpi
+  //! @{
+
+  constexpr char const rsdt_table_signature[] = "RSDT";  // NOLINT
+
+  template<>
+  struct table_type<rsdt_table_signature>
+  {
+    using type = system_description_table_header;
+  };
+
+  //! @}
+
+}  // namespace kapi::acpi
+
+#endif
diff --git a/kapi/include/kapi/acpi/table_iterator.hpp b/kapi/include/kapi/acpi/table_iterator.hpp
new file mode 100644
index 0000000..998d6d6
--- /dev/null
+++ b/kapi/include/kapi/acpi/table_iterator.hpp
@@ -0,0 +1,64 @@
+#ifndef TEACHOS_KAPI_ACPI_TABLE_ITERATOR_HPP
+#define TEACHOS_KAPI_ACPI_TABLE_ITERATOR_HPP
+
+#include <bit>
+#include <cstddef>
+#include <iterator>
+
+namespace kapi::acpi
+{
+
+  template<typename EntryType>
+  struct table_iterator
+  {
+    using iterator_category = std::forward_iterator_tag;
+    using value_type = EntryType;
+    using pointer = value_type *;
+    using reference = value_type &;
+    using difference_type = std::ptrdiff_t;
+
+    constexpr table_iterator() noexcept = default;
+
+    constexpr table_iterator(pointer entry, pointer limit) noexcept
+        : m_entry{entry}
+        , m_limit{limit}
+    {}
+
+    constexpr auto operator++() noexcept -> table_iterator &
+    {
+      auto decayed = std::bit_cast<std::byte *>(m_entry);
+      decayed += m_entry->length();
+      m_entry = std::bit_cast<pointer>(decayed);
+      return *this;
+    }
+
+    constexpr auto operator++(int) noexcept -> table_iterator
+    {
+      auto copy = *this;
+      ++*this;
+      return copy;
+    }
+
+    constexpr auto operator*() const noexcept -> reference
+    {
+      return *m_entry;
+    }
+
+    constexpr auto operator==(table_iterator const & other) const noexcept -> bool
+    {
+      return m_entry == other.m_entry || (is_end() && other.is_end());
+    }
+
+  private:
+    [[nodiscard]] constexpr auto is_end() const noexcept -> bool
+    {
+      return m_entry == m_limit;
+    }
+
+    pointer m_entry{};
+    pointer m_limit{};
+  };
+
+}  // namespace kapi::acpi
+
+#endif
diff --git a/kapi/include/kapi/acpi/table_type.hpp b/kapi/include/kapi/acpi/table_type.hpp
new file mode 100644
index 0000000..e088a24
--- /dev/null
+++ b/kapi/include/kapi/acpi/table_type.hpp
@@ -0,0 +1,22 @@
+#ifndef TEACHOS_KAPI_ACPI_TABLE_TYPE_HPP
+#define TEACHOS_KAPI_ACPI_TABLE_TYPE_HPP
+
+// IWYU pragma: private
+
+namespace kapi::acpi
+{
+
+  //! @addtogroup kapi-acpi-kernel-defined
+  //! @{
+
+  template<char const *>
+  struct table_type;
+
+  template<char const * Signature>
+  using table_type_t = typename table_type<Signature>::type;
+
+  //! @}
+
+}  // namespace kapi::acpi
+
+#endif
diff --git a/kernel/CMakeLists.txt b/kernel/CMakeLists.txt
index 67db0a8..8af6fe7 100644
--- a/kernel/CMakeLists.txt
+++ b/kernel/CMakeLists.txt
@@ -1,6 +1,9 @@
 add_library("kernel_objs" OBJECT
     # Platform-independent KAPI implementation
     "kapi/acpi.cpp"
+    "kapi/acpi/multiple_apic_description_table.cpp"
+    "kapi/acpi/pointers.cpp"
+    "kapi/acpi/system_description_table_header.cpp"
     "kapi/boot_modules.cpp"
     "kapi/cio.cpp"
     "kapi/cpu.cpp"
diff --git a/kernel/kapi/acpi.cpp b/kernel/kapi/acpi.cpp
index 1283d7e..e7c4921 100644
--- a/kernel/kapi/acpi.cpp
+++ b/kernel/kapi/acpi.cpp
@@ -1,16 +1,13 @@
 #include "kapi/acpi.hpp"
 
-#include "kapi/memory.hpp"
 #include "kapi/system.hpp"
 
 #include "kernel/acpi/manager.hpp"
 
 #include <kstd/memory>
-#include <kstd/units>
 
 #include <algorithm>
 #include <atomic>
-#include <bit>
 #include <cstddef>
 #include <cstdint>
 #include <optional>
@@ -25,127 +22,6 @@ namespace kapi::acpi
     auto constinit manager = std::optional<kernel::acpi::manager>{};
   }  // 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});
-  }
-
-  [[nodiscard]] auto system_description_table_header::checksum() const noexcept -> std::uint8_t
-  {
-    return m_checksum;
-  }
-
-  [[nodiscard]] auto system_description_table_header::creator_revision() const noexcept -> std::uint32_t
-  {
-    return m_creator_revision;
-  }
-
-  [[nodiscard]] auto system_description_table_header::creator_id() const noexcept -> std::uint32_t
-  {
-    return m_creator_id;
-  }
-
-  [[nodiscard]] auto system_description_table_header::length() const noexcept -> kstd::units::bytes
-  {
-    return kstd::units::bytes{m_length};
-  }
-
-  [[nodiscard]] auto system_description_table_header::oem_id() const noexcept -> std::string_view
-  {
-    return {m_oem_id.data(), m_oem_id.size()};
-  }
-
-  [[nodiscard]] auto system_description_table_header::oem_revision() const noexcept -> std::uint32_t
-  {
-    return m_oem_revision;
-  }
-
-  [[nodiscard]] auto system_description_table_header::oem_table_id() const noexcept -> std::string_view
-  {
-    return {m_oem_table_id.data(), m_oem_table_id.size()};
-  }
-
-  [[nodiscard]] auto system_description_table_header::revision() const noexcept -> std::uint8_t
-  {
-    return m_revision;
-  }
-
-  [[nodiscard]] auto system_description_table_header::signature() const noexcept -> std::string_view
-  {
-    return {m_signature.data(), m_signature.size()};
-  }
-
-  [[nodiscard]] auto madt_header::local_interrupt_controller_address() const noexcept -> memory::physical_address
-  {
-    return memory::physical_address{static_cast<std::uintptr_t>(m_local_interrupt_controller_address)};
-  }
-
-  [[nodiscard]] auto madt_header::flags() const noexcept -> std::uint32_t
-  {
-    return m_flags;
-  }
-
-  [[nodiscard]] auto madt_subtable_header::type() const noexcept -> std::uint8_t
-  {
-    return m_type;
-  }
-
-  [[nodiscard]] auto madt_subtable_header::length() const noexcept -> std::size_t
-  {
-    return m_length;
-  }
-
-  [[nodiscard]] auto madt_local_apic::apic_id() const noexcept -> std::uint8_t
-  {
-    return m_apic_id;
-  }
-
-  [[nodiscard]] auto madt_local_apic::flags() const noexcept -> std::uint32_t
-  {
-    return m_flags;
-  }
-
-  [[nodiscard]] auto madt_local_apic::processor_id() const noexcept -> std::uint32_t
-  {
-    return m_processor_id;
-  }
-
   auto init(root_system_description_pointer const & sdp) -> bool
   {
     auto static constinit initialized = std::atomic_flag{};
diff --git a/kernel/kapi/acpi/multiple_apic_description_table.cpp b/kernel/kapi/acpi/multiple_apic_description_table.cpp
new file mode 100644
index 0000000..c0360a3
--- /dev/null
+++ b/kernel/kapi/acpi/multiple_apic_description_table.cpp
@@ -0,0 +1,70 @@
+#include "kapi/acpi.hpp"
+#include "kapi/memory.hpp"
+
+#include <cstddef>
+#include <cstdint>
+
+namespace kapi::acpi
+{
+
+  auto multiple_apic_description_table::local_interrupt_controller_address() const noexcept -> memory::physical_address
+  {
+    return memory::physical_address{static_cast<std::uintptr_t>(m_local_interrupt_controller_address)};
+  }
+
+  auto multiple_apic_description_table::flags() const noexcept -> std::uint32_t
+  {
+    return m_flags;
+  }
+
+  auto multiple_apic_description_table_entry::type() const noexcept -> types
+  {
+    return static_cast<types>(m_type);
+  }
+
+  auto multiple_apic_description_table_entry::length() const noexcept -> std::size_t
+  {
+    return m_length;
+  }
+
+  auto processor_local_apic::apic_id() const noexcept -> std::uint8_t
+  {
+    return m_apic_id;
+  }
+
+  auto processor_local_apic::active_flags() const noexcept -> flags
+  {
+    return static_cast<flags>(m_flags);
+  }
+
+  auto processor_local_apic::processor_id() const noexcept -> std::uint32_t
+  {
+    return m_processor_id;
+  }
+
+  auto multiple_apic_description_table::begin() const noexcept -> iterator
+  {
+    auto base = reinterpret_cast<std::byte const *>(this);
+    base += sizeof(multiple_apic_description_table);
+    auto limit = reinterpret_cast<std::byte const *>(this);
+    limit += length().value;
+    return iterator{reinterpret_cast<multiple_apic_description_table_entry const *>(base),
+                    reinterpret_cast<multiple_apic_description_table_entry const *>(limit)};
+  }
+
+  auto multiple_apic_description_table::cbegin() const noexcept -> iterator
+  {
+    return begin();
+  }
+
+  auto multiple_apic_description_table::end() const noexcept -> iterator
+  {
+    return {};
+  }
+
+  auto multiple_apic_description_table::cend() const noexcept -> iterator
+  {
+    return end();
+  }
+
+}  // namespace kapi::acpi
diff --git a/kernel/kapi/acpi/pointers.cpp b/kernel/kapi/acpi/pointers.cpp
new file mode 100644
index 0000000..63831e9
--- /dev/null
+++ b/kernel/kapi/acpi/pointers.cpp
@@ -0,0 +1,55 @@
+#include "kapi/acpi.hpp"
+#include "kapi/memory.hpp"
+
+#include <kstd/units>
+
+#include <bit>
+#include <cstddef>
+#include <cstdint>
+#include <string_view>
+
+namespace kapi::acpi
+{
+
+  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
diff --git a/kernel/kapi/acpi/system_description_table_header.cpp b/kernel/kapi/acpi/system_description_table_header.cpp
new file mode 100644
index 0000000..f688b4d
--- /dev/null
+++ b/kernel/kapi/acpi/system_description_table_header.cpp
@@ -0,0 +1,51 @@
+#include "kapi/acpi.hpp"
+
+#include <kstd/units>
+
+#include <cstdint>
+#include <string_view>
+
+namespace kapi::acpi
+{
+
+  [[nodiscard]] auto system_description_table_header::creator_revision() const noexcept -> std::uint32_t
+  {
+    return m_creator_revision;
+  }
+
+  [[nodiscard]] auto system_description_table_header::creator_id() const noexcept -> std::uint32_t
+  {
+    return m_creator_id;
+  }
+
+  [[nodiscard]] auto system_description_table_header::length() const noexcept -> kstd::units::bytes
+  {
+    return kstd::units::bytes{m_length};
+  }
+
+  [[nodiscard]] auto system_description_table_header::oem_id() const noexcept -> std::string_view
+  {
+    return {m_oem_id.data(), m_oem_id.size()};
+  }
+
+  [[nodiscard]] auto system_description_table_header::oem_revision() const noexcept -> std::uint32_t
+  {
+    return m_oem_revision;
+  }
+
+  [[nodiscard]] auto system_description_table_header::oem_table_id() const noexcept -> std::string_view
+  {
+    return {m_oem_table_id.data(), m_oem_table_id.size()};
+  }
+
+  [[nodiscard]] auto system_description_table_header::revision() const noexcept -> std::uint8_t
+  {
+    return m_revision;
+  }
+
+  [[nodiscard]] auto system_description_table_header::signature() const noexcept -> std::string_view
+  {
+    return {m_signature.data(), m_signature.size()};
+  }
+
+}  // namespace kapi::acpi