kapi: extract ACPI functionality to libs

25 files changed, 406 insertions, 393 deletions

diff --git a/arch/x86_64/kapi/acpi.cpp b/arch/x86_64/kapi/acpi.cpp
index ec38aee..40b7160 100644
--- a/arch/x86_64/kapi/acpi.cpp
+++ b/arch/x86_64/kapi/acpi.cpp
@@ -4,24 +4,26 @@
 
 #include <kstd/memory>
 
+#include <acpi/acpi.hpp>
+
 namespace kapi::acpi
 {
 
-  auto get_root_pointer() -> kstd::observer_ptr<root_system_description_pointer const>
+  auto get_root_pointer() -> kstd::observer_ptr<::acpi::rsdp const>
   {
     auto const & mbi = kapi::boot::bootstrap_information.mbi;
-    auto system_description_pointer = static_cast<kapi::acpi::root_system_description_pointer const *>(nullptr);
+    auto system_description_pointer = static_cast<::acpi::rsdp const *>(nullptr);
 
     if (auto const & xsdp = mbi->maybe_acpi_xsdp())
     {
       auto data = xsdp->pointer().data();
 
-      system_description_pointer = reinterpret_cast<kapi::acpi::root_system_description_pointer const *>(data);
+      system_description_pointer = reinterpret_cast<::acpi::xsdp const *>(data);
     }
     else if (auto const & rsdp = mbi->maybe_acpi_rsdp())
     {
       auto data = rsdp->pointer().data();
-      system_description_pointer = reinterpret_cast<kapi::acpi::root_system_description_pointer const *>(data);
+      system_description_pointer = reinterpret_cast<::acpi::rsdp const *>(data);
     }
 
     return kstd::make_observer(system_description_pointer);
diff --git a/arch/x86_64/kapi/cpu.cpp b/arch/x86_64/kapi/cpu.cpp
index 726ec6a..a836b20 100644
--- a/arch/x86_64/kapi/cpu.cpp
+++ b/arch/x86_64/kapi/cpu.cpp
@@ -3,6 +3,7 @@
 #include "kapi/acpi.hpp"
 #include "kapi/devices.hpp"
 #include "kapi/devices/cpu.hpp"
+#include "kapi/memory.hpp"
 #include "kapi/system.hpp"
 
 #include "arch/cpu/initialization.hpp"
@@ -11,6 +12,8 @@
 #include <kstd/memory>
 #include <kstd/print>
 
+#include <acpi/acpi.hpp>
+
 #include <atomic>
 #include <ranges>
 #include <utility>
@@ -20,8 +23,8 @@ namespace kapi::cpu
 
   namespace
   {
-    constexpr auto candidate_flags = acpi::processor_local_apic::flags::processor_enabled  //
-                                     | acpi::processor_local_apic::flags::online_capable;
+    constexpr auto candidate_flags = ::acpi::processor_local_apic::flags::processor_enabled  //
+                                     | ::acpi::processor_local_apic::flags::online_capable;
   }
 
   auto init() -> void
@@ -49,7 +52,7 @@ namespace kapi::cpu
     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<acpi::madt_table_signature>();
+    auto madt = kapi::acpi::get_table<::acpi::madt_table_signature>();
     if (!madt)
     {
       kstd::println("[x86_64:PLT] Failed to find ACPI APIC table");
@@ -57,16 +60,16 @@ namespace kapi::cpu
     }
 
     auto lapic_entries = *madt | std::views::filter([](auto const & entry) {
-      return entry.type() == acpi::multiple_apic_description_table_entry::types::processor_local_apic;
+      return entry.type() == ::acpi::madt_entry::types::processor_local_apic;
     }) | std::views::transform([](auto const & entry) {
-      return static_cast<acpi::processor_local_apic 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);
     });
 
     auto bsp_found = false;
     auto core_count = 0uz;
-    auto local_apic_address = madt->local_interrupt_controller_address();
+    auto local_apic_address = memory::physical_address{madt->local_interrupt_controller_address()};
     auto cpu_bus = kstd::make_unique<devices::cpu>(cpu_major, 0);
 
     for (auto const & apic : lapic_entries)
diff --git a/kapi/CMakeLists.txt b/kapi/CMakeLists.txt
index c9aa23f..99a8725 100644
--- a/kapi/CMakeLists.txt
+++ b/kapi/CMakeLists.txt
@@ -15,6 +15,7 @@ target_include_directories("kapi" INTERFACE
 )
 
 target_link_libraries("kapi" INTERFACE
+    "libs::acpi"
     "libs::kstd"
 
     "gcc"
diff --git a/kapi/include/kapi/acpi.hpp b/kapi/include/kapi/acpi.hpp
index 5323fee..01fd113 100644
--- a/kapi/include/kapi/acpi.hpp
+++ b/kapi/include/kapi/acpi.hpp
@@ -1,16 +1,11 @@
 #ifndef TEACHOS_KAPI_ACPI_HPP
 #define TEACHOS_KAPI_ACPI_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 <cstddef>
-#include <span>
+#include <acpi/acpi.hpp>
+
 #include <string_view>
 
 namespace kapi::acpi
@@ -22,28 +17,22 @@ namespace kapi::acpi
   //! Initialize the ACPI subsystem and discover the available tables.
   //!
   //! @return true iff. a valid system description tabled was found, false otherwise.
-  auto init(root_system_description_pointer const & sdp) -> bool;
-
-  //! Validate and ACPI entity checksum.
-  //!
-  //! @param data The data to validate the checksum of.
-  //! @return true iff. the checksum is valid, false otherwise.
-  auto validate_checksum(std::span<std::byte const> data) -> bool;
+  auto init(::acpi::rsdp const & sdp) -> bool;
 
   //! 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>;
+  auto get_table(std::string_view signature) -> kstd::observer_ptr<::acpi::sdt 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>
+  auto get_table() -> kstd::observer_ptr<::acpi::table_type_t<Signature> const>
   {
-    return kstd::make_observer(static_cast<table_type_t<Signature> const *>(get_table(Signature).get()));
+    return kstd::make_observer(static_cast<::acpi::table_type_t<Signature> const *>(get_table(Signature).get()));
   }
 
   //! @}
@@ -54,7 +43,7 @@ namespace kapi::acpi
   //! 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>;
+  auto get_root_pointer() -> kstd::observer_ptr<::acpi::rsdp const>;
 
   //! @}
 
diff --git a/kapi/include/kapi/acpi/table_iterator.hpp b/kapi/include/kapi/acpi/table_iterator.hpp
deleted file mode 100644
index 998d6d6..0000000
--- a/kapi/include/kapi/acpi/table_iterator.hpp
+++ /dev/null
@@ -1,64 +0,0 @@
-#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
deleted file mode 100644
index e088a24..0000000
--- a/kapi/include/kapi/acpi/table_type.hpp
+++ /dev/null
@@ -1,22 +0,0 @@
-#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 b9e01eb..74233cb 100644
--- a/kernel/CMakeLists.txt
+++ b/kernel/CMakeLists.txt
@@ -1,9 +1,6 @@
 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/include/kernel/acpi/manager.hpp b/kernel/include/kernel/acpi/manager.hpp
index fae59a6..420b44a 100644
--- a/kernel/include/kernel/acpi/manager.hpp
+++ b/kernel/include/kernel/acpi/manager.hpp
@@ -1,12 +1,12 @@
 #ifndef TEACHOS_KERNEL_ACPI_MANAGER_HPP
 #define TEACHOS_KERNEL_ACPI_MANAGER_HPP
 
-#include "kapi/acpi.hpp"
-
 #include <kstd/flat_map>
 #include <kstd/memory>
 #include <kstd/vector>
 
+#include <acpi/acpi.hpp>
+
 #include <string_view>
 
 namespace kernel::acpi
@@ -14,16 +14,16 @@ namespace kernel::acpi
 
   struct manager
   {
-    explicit manager(kapi::acpi::root_system_description_pointer const & sdp);
+    explicit manager(::acpi::rsdp const & sdp);
 
     auto load_tables() -> bool;
 
-    auto get_table(std::string_view signature) -> kstd::observer_ptr<kapi::acpi::system_description_table_header const>;
+    auto get_table(std::string_view signature) -> kstd::observer_ptr<::acpi::sdt const>;
 
   private:
-    kapi::acpi::root_system_description_pointer const * m_sdp{};
-    kapi::acpi::system_description_table_header const * m_rsdt{};
-    kstd::flat_map<std::string_view, kapi::acpi::system_description_table_header const *> m_tables{};
+    ::acpi::rsdp const * m_sdp{};
+    ::acpi::sdt const * m_rsdt{};
+    kstd::flat_map<std::string_view, ::acpi::sdt const *> m_tables{};
     bool m_extended{};
   };
 
diff --git a/kernel/kapi/acpi.cpp b/kernel/kapi/acpi.cpp
index e7c4921..df2bf05 100644
--- a/kernel/kapi/acpi.cpp
+++ b/kernel/kapi/acpi.cpp
@@ -6,12 +6,10 @@
 
 #include <kstd/memory>
 
-#include <algorithm>
+#include <acpi/acpi.hpp>
+
 #include <atomic>
-#include <cstddef>
-#include <cstdint>
 #include <optional>
-#include <span>
 #include <string_view>
 
 namespace kapi::acpi
@@ -22,7 +20,7 @@ namespace kapi::acpi
     auto constinit manager = std::optional<kernel::acpi::manager>{};
   }  // namespace
 
-  auto init(root_system_description_pointer const & sdp) -> bool
+  auto init(::acpi::rsdp const & sdp) -> bool
   {
     auto static constinit initialized = std::atomic_flag{};
     if (initialized.test_and_set())
@@ -34,15 +32,7 @@ namespace kapi::acpi
     return manager->load_tables();
   }
 
-  auto validate_checksum(std::span<std::byte const> data) -> bool
-  {
-    auto sum = std::ranges::fold_left(data, std::uint8_t{}, [](auto acc, auto byte) {
-      return static_cast<std::uint8_t>(acc + static_cast<std::uint8_t>(byte));
-    });
-    return sum == 0;
-  }
-
-  auto get_table(std::string_view signature) -> kstd::observer_ptr<system_description_table_header const>
+  auto get_table(std::string_view signature) -> kstd::observer_ptr<::acpi::sdt const>
   {
     return manager->get_table(signature);
   }
diff --git a/kernel/kapi/acpi/multiple_apic_description_table.cpp b/kernel/kapi/acpi/multiple_apic_description_table.cpp
deleted file mode 100644
index c0360a3..0000000
--- a/kernel/kapi/acpi/multiple_apic_description_table.cpp
+++ /dev/null
@@ -1,70 +0,0 @@
-#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
deleted file mode 100644
index 63831e9..0000000
--- a/kernel/kapi/acpi/pointers.cpp
+++ /dev/null
@@ -1,55 +0,0 @@
-#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
deleted file mode 100644
index f688b4d..0000000
--- a/kernel/kapi/acpi/system_description_table_header.cpp
+++ /dev/null
@@ -1,51 +0,0 @@
-#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
diff --git a/kernel/src/acpi/manager.cpp b/kernel/src/acpi/manager.cpp
index 300b85e..501ce92 100644
--- a/kernel/src/acpi/manager.cpp
+++ b/kernel/src/acpi/manager.cpp
@@ -1,12 +1,13 @@
 #include "kernel/acpi/manager.hpp"
 
-#include "kapi/acpi.hpp"
 #include "kapi/memory.hpp"
 #include "kapi/system.hpp"
 
 #include <kstd/memory>
 #include <kstd/print>
 
+#include <acpi/acpi.hpp>
+
 #include <cstddef>
 #include <cstdint>
 #include <string_view>
@@ -14,7 +15,7 @@
 namespace kernel::acpi
 {
 
-  manager::manager(kapi::acpi::root_system_description_pointer const & sdp)
+  manager::manager(::acpi::rsdp const & sdp)
       : m_sdp{&sdp}
   {
     if (m_sdp->signature() != "RSD PTR ")
@@ -24,14 +25,14 @@ namespace kernel::acpi
 
     if (m_sdp->revision() >= 2)
     {
-      auto const xsdp = static_cast<kapi::acpi::extended_system_description_pointer const *>(m_sdp);
+      auto const xsdp = static_cast<::acpi::xsdp const *>(m_sdp);
       if (!xsdp->validate())
       {
         kapi::system::panic("[OS:ACPI] Invalid XSDP signature!");
       }
-      auto physical_extended_table_address = xsdp->table_address();
+      auto physical_extended_table_address = kapi::memory::physical_address{xsdp->table_address()};
       auto linear_extended_table_address = kapi::memory::hhdm_to_linear(physical_extended_table_address);
-      m_rsdt = static_cast<kapi::acpi::system_description_table_header const *>(linear_extended_table_address);
+      m_rsdt = static_cast<::acpi::sdt const *>(linear_extended_table_address);
       m_extended = true;
     }
     else
@@ -40,23 +41,22 @@ namespace kernel::acpi
       {
         kapi::system::panic("[OS:ACPI] Invalid RSDP checksum!");
       }
-      auto physical_root_table_address = m_sdp->table_address();
+      auto physical_root_table_address = kapi::memory::physical_address{m_sdp->table_address()};
       auto linear_root_table_address = kapi::memory::hhdm_to_linear(physical_root_table_address);
-      m_rsdt = static_cast<kapi::acpi::system_description_table_header const *>(linear_root_table_address);
+      m_rsdt = static_cast<::acpi::sdt const *>(linear_root_table_address);
     }
   }
 
   auto manager::load_tables() -> bool
   {
-    if (!kapi::acpi::validate_checksum({reinterpret_cast<std::byte const *>(m_rsdt), m_rsdt->length().value}))
+    if (!::acpi::validate_checksum({reinterpret_cast<std::byte const *>(m_rsdt), m_rsdt->length().value}))
     {
       kapi::system::panic("[OS:ACPI] Invalid RSDT checksum!");
     }
 
     auto entry_size = m_extended ? sizeof(std::uint64_t) : sizeof(std::uint32_t);
-    auto entry_count = (m_rsdt->length().value - sizeof(kapi::acpi::system_description_table_header)) / entry_size;
-    auto entries_base =
-        reinterpret_cast<std::byte const *>(m_rsdt) + sizeof(kapi::acpi::system_description_table_header);
+    auto entry_count = (m_rsdt->length().value - sizeof(::acpi::sdt)) / entry_size;
+    auto entries_base = reinterpret_cast<std::byte const *>(m_rsdt) + sizeof(::acpi::sdt);
 
     for (std::size_t i = 0; i < entry_count; ++i)
     {
@@ -74,9 +74,9 @@ namespace kernel::acpi
       }
 
       auto linear_table_address = kapi::memory::hhdm_to_linear(physical_table_address);
-      auto table = static_cast<kapi::acpi::system_description_table_header const *>(linear_table_address);
+      auto table = static_cast<::acpi::sdt const *>(linear_table_address);
 
-      if (!kapi::acpi::validate_checksum({reinterpret_cast<std::byte const *>(table), table->length().value}))
+      if (!::acpi::validate_checksum({reinterpret_cast<std::byte const *>(table), table->length().value}))
       {
         kstd::println(kstd::print_sink::stderr, "[OS:ACPI] Invalid table checksum!");
       }
@@ -90,8 +90,7 @@ namespace kernel::acpi
     return !m_tables.empty();
   }
 
-  auto manager::get_table(std::string_view signature)
-      -> kstd::observer_ptr<kapi::acpi::system_description_table_header const>
+  auto manager::get_table(std::string_view signature) -> kstd::observer_ptr<::acpi::sdt const>
   {
     if (m_tables.contains(signature))
     {
diff --git a/libs/CMakeLists.txt b/libs/CMakeLists.txt
index 58d9796..2b61992 100644
--- a/libs/CMakeLists.txt
+++ b/libs/CMakeLists.txt
@@ -1,3 +1,4 @@
+add_subdirectory("acpi" EXCLUDE_FROM_ALL SYSTEM)
 add_subdirectory("elf" EXCLUDE_FROM_ALL SYSTEM)
 add_subdirectory("kstd" EXCLUDE_FROM_ALL SYSTEM)
-add_subdirectory("multiboot2" EXCLUDE_FROM_ALL SYSTEM)
\ No newline at end of file
+add_subdirectory("multiboot2" EXCLUDE_FROM_ALL SYSTEM)
diff --git a/libs/acpi/CMakeLists.txt b/libs/acpi/CMakeLists.txt
new file mode 100644
index 0000000..c6e63b9
--- /dev/null
+++ b/libs/acpi/CMakeLists.txt
@@ -0,0 +1,29 @@
+add_library("acpi" STATIC)
+add_library("libs::acpi" ALIAS "acpi")
+
+target_include_directories("acpi" PUBLIC
+  "${CMAKE_CURRENT_SOURCE_DIR}"
+)
+
+file(GLOB_RECURSE ACPI_HEADERS
+  RELATIVE ${CMAKE_CURRENT_SOURCE_DIR}
+  "acpi/*.hpp"
+)
+
+target_sources("acpi" PRIVATE
+  "acpi/checksum.cpp"
+  "acpi/madt.cpp"
+  "acpi/pointers.cpp"
+  "acpi/sdt.cpp"
+)
+
+target_sources("acpi" PUBLIC
+  FILE_SET HEADERS
+  BASE_DIRS "acpi"
+  FILES
+  ${ACPI_HEADERS}
+)
+
+target_link_libraries("acpi" PUBLIC
+  "libs::kstd"
+)
diff --git a/libs/acpi/acpi/acpi.hpp b/libs/acpi/acpi/acpi.hpp
new file mode 100644
index 0000000..fb358cc
--- /dev/null
+++ b/libs/acpi/acpi/acpi.hpp
@@ -0,0 +1,10 @@
+#ifndef ACPI_ACPI_HPP
+#define ACPI_ACPI_HPP
+
+#include <acpi/checksum.hpp>    // IWYU pragma: export
+#include <acpi/madt.hpp>        // IWYU pragma: export
+#include <acpi/pointers.hpp>    // IWYU pragma: export
+#include <acpi/sdt.hpp>         // IWYU pragma: export
+#include <acpi/table_type.hpp>  // IWYU pragma: export
+
+#endif
diff --git a/libs/acpi/acpi/checksum.cpp b/libs/acpi/acpi/checksum.cpp
new file mode 100644
index 0000000..56275c8
--- /dev/null
+++ b/libs/acpi/acpi/checksum.cpp
@@ -0,0 +1,19 @@
+#include <acpi/checksum.hpp>
+
+#include <algorithm>
+#include <cstddef>
+#include <cstdint>
+#include <span>
+
+namespace acpi
+{
+
+  auto validate_checksum(std::span<std::byte const> data) -> bool
+  {
+    auto sum = std::ranges::fold_left(data, std::uint8_t{}, [](auto acc, auto byte) {
+      return static_cast<std::uint8_t>(acc + static_cast<std::uint8_t>(byte));
+    });
+    return sum == 0;
+  }
+
+}  // namespace acpi
diff --git a/libs/acpi/acpi/checksum.hpp b/libs/acpi/acpi/checksum.hpp
new file mode 100644
index 0000000..a92c242
--- /dev/null
+++ b/libs/acpi/acpi/checksum.hpp
@@ -0,0 +1,20 @@
+#ifndef ACPI_CHECKSUM_HPP
+#define ACPI_CHECKSUM_HPP
+
+// IWYU pragma: private, include <acpi/acpi.hpp>
+
+#include <cstddef>
+#include <span>
+
+namespace acpi
+{
+
+  //! Validate and ACPI entity checksum.
+  //!
+  //! @param data The data to validate the checksum of.
+  //! @return true iff. the checksum is valid, false otherwise.
+  auto validate_checksum(std::span<std::byte const> data) -> bool;
+
+}  // namespace acpi
+
+#endif
diff --git a/libs/acpi/acpi/madt.cpp b/libs/acpi/acpi/madt.cpp
new file mode 100644
index 0000000..40289cf
--- /dev/null
+++ b/libs/acpi/acpi/madt.cpp
@@ -0,0 +1,68 @@
+#include <acpi/madt.hpp>
+
+#include <cstddef>
+#include <cstdint>
+
+namespace acpi
+{
+
+  auto madt::local_interrupt_controller_address() const noexcept -> std::uintptr_t
+  {
+    return static_cast<std::uintptr_t>(m_local_interrupt_controller_address);
+  }
+
+  auto madt::flags() const noexcept -> std::uint32_t
+  {
+    return m_flags;
+  }
+
+  auto madt_entry::type() const noexcept -> types
+  {
+    return static_cast<types>(m_type);
+  }
+
+  auto madt_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 madt::begin() const noexcept -> iterator
+  {
+    auto base = reinterpret_cast<std::byte const *>(this);
+    base += sizeof(madt);
+    auto limit = reinterpret_cast<std::byte const *>(this);
+    limit += length().value;
+    return iterator{reinterpret_cast<madt_entry const *>(base), reinterpret_cast<madt_entry const *>(limit)};
+  }
+
+  auto madt::cbegin() const noexcept -> iterator
+  {
+    return begin();
+  }
+
+  auto madt::end() const noexcept -> iterator
+  {
+    return {};
+  }
+
+  auto madt::cend() const noexcept -> iterator
+  {
+    return end();
+  }
+