x86_64: use p1204 project layout

32 files changed, 0 insertions, 1941 deletions

diff --git a/arch/x86_64/include/arch/boot/boot.hpp b/arch/x86_64/include/arch/boot/boot.hpp
deleted file mode 100644
index 7df61c4..0000000
--- a/arch/x86_64/include/arch/boot/boot.hpp
+++ /dev/null
@@ -1,56 +0,0 @@
-#ifndef TEACHOS_X86_64_BOOT_BOOT_HPP
-#define TEACHOS_X86_64_BOOT_BOOT_HPP
-
-#ifdef __ASSEMBLER__
-// clang-format off
-
-//! The number of huge pages to map during bootstrap.
-#define HUGE_PAGES_TO_MAP (16)
-
-//! The magic value to be set in eax by the multiboot 2 loader.
-#define MULTIBOOT2_MAGIC (0x36d76289)
-
-//! The "A" bit in a GDT entry.
-#define GDT_ACCESSED (1 << 40)
-
-//! The "R/W" bit in a GDT entry
-#define GDT_READ_WRITE (1 << 41)
-
-//! The "E" bit in a GDT entry.
-#define GDT_EXECUTABLE (1 << 43)
-
-//! The "S" bit in a GDT entry.
-#define GDT_DESCRIPTOR_TYPE (1 << 44)
-
-//! The "P" bit in a GDT entry.
-#define GDT_PRESENT (1 << 47)
-
-//! The "L" bit in a GDT entry.
-#define GDT_LONG_MODE (1 << 53)
-
-// clang-format on
-#else
-
-#include <kapi/boot.hpp>  // IWYU pragma: export
-
-#include <multiboot2/information.hpp>
-
-#include <cstddef>
-
-namespace kapi::boot
-{
-
-  struct information
-  {
-    //! A pointer to the loader provided Multiboot2 Information structure.
-    multiboot2::information_view const * mbi;
-
-    //! The index of the next character to be written in the VGA text buffer after handoff.
-    std::size_t vga_buffer_index;
-  };
-
-}  // namespace kapi::boot
-
-#endif
-
-#endif
diff --git a/arch/x86_64/include/arch/boot/ld.hpp b/arch/x86_64/include/arch/boot/ld.hpp
deleted file mode 100644
index 988723d..0000000
--- a/arch/x86_64/include/arch/boot/ld.hpp
+++ /dev/null
@@ -1,61 +0,0 @@
-//! @file
-//! The interface to linker script defined symbols.
-//!
-//! This header provides declarations for symbols that are defined in the linker script itself. The symbols declared
-//! here provide important information, for example the start and end of the kernel image in virtual and physical
-//! memory.
-//!
-//! Any variables defined in this file must not be read themselves, but rather their address shall be taken, yielding a
-//! pointer to the memory location the represent.
-//!
-//! @note The symbols declared in this header are declared using C-language linkage in order to suppress name mangling.
-//!
-//! @see arch/x86_64/scripts/kernel.ld
-
-#ifndef TEACHOS_X86_64_BOOT_LD_HPP
-#define TEACHOS_X86_64_BOOT_LD_HPP
-
-#include <cstddef>
-
-namespace arch::boot
-{
-
-  extern "C"
-  {
-    //! The beginning of the kernel image in physical memory
-    //!
-    //! This symbol marks the start of the kernel image in physical memory.
-    //!
-    //! @see _end_physical
-    extern std::byte _start_physical;
-
-    //! The first byte after the loaded kernel image.
-    //!
-    //! This symbol marks the end of the kernel image in physical memory.
-    //!
-    //! @see _start_physical
-    extern std::byte _end_physical;
-
-    //! The first byte of the loaded kernel image in the virtual address space.
-    //!
-    //! This symbol and marks the start of the kernel image in virtual memory.
-    //!
-    //! @see _end_virtual
-    extern std::byte _start_virtual;
-
-    //! The first byte after the loaded kernel image in the virtual address space.
-    //!
-    //! This symbol marks the end of the kernel image in virtual memory.
-    //!
-    //! @see _start_virtual
-    extern std::byte _end_virtual;
-
-    //! The first byte of the kernel's virtual address space.
-    //!
-    //! This symbol marks beginning of the kernel virtual address space.
-    extern std::byte TEACHOS_VMA;
-  }
-
-}  // namespace arch::boot
-
-#endif
diff --git a/arch/x86_64/include/arch/bus/isa.hpp b/arch/x86_64/include/arch/bus/isa.hpp
deleted file mode 100644
index e56f56a..0000000
--- a/arch/x86_64/include/arch/bus/isa.hpp
+++ /dev/null
@@ -1,18 +0,0 @@
-#ifndef TEACHOS_X86_64_BUS_ISA_HPP
-#define TEACHOS_X86_64_BUS_ISA_HPP
-
-#include <kapi/devices/bus.hpp>
-
-#include <cstddef>
-
-namespace arch::bus
-{
-
-  struct isa final : public kapi::devices::bus
-  {
-    isa(std::size_t major);
-  };
-
-}  // namespace arch::bus
-
-#endif  // TEACHOS_X86_64_BUS_ISA_HPP
diff --git a/arch/x86_64/include/arch/cpu/control_register.hpp b/arch/x86_64/include/arch/cpu/control_register.hpp
deleted file mode 100644
index 9cedc35..0000000
--- a/arch/x86_64/include/arch/cpu/control_register.hpp
+++ /dev/null
@@ -1,249 +0,0 @@
-#ifndef TEACHOS_X86_64_CPU_CONTROL_REGISTERS_HPP
-#define TEACHOS_X86_64_CPU_CONTROL_REGISTERS_HPP
-
-// IWYU pragma: private, include <arch/cpu/registers.hpp>
-
-#include <kapi/memory.hpp>
-
-#include <kstd/ext/bitfield_enum>
-
-#include <cstdint>
-#include <string_view>
-#include <type_traits>
-#include <utility>
-
-namespace arch::cpu
-{
-  namespace impl
-  {
-    //! The assembler templates used to access (r/w) CR0;
-    constexpr auto static cr0_asm = std::pair<std::string_view, std::string_view>{"mov %%cr0, %0", "mov %0, %%cr0"};
-
-    //! The assembler templates used to access (r/w) CR2;
-    constexpr auto static cr2_asm = std::pair<std::string_view, std::string_view>{"mov %%cr2, %0", "mov %0, %%cr2"};
-
-    //! The assembler templates used to access (r/w) CR3;
-    constexpr auto static cr3_asm = std::pair<std::string_view, std::string_view>{"mov %%cr3, %0", "mov %0, %%cr3"};
-  }  // namespace impl
-
-  //! The flags that can be set on CR0 configuration register.
-  enum struct cr0_flags : uint64_t
-  {
-    //! Enable protected mode.
-    protection_enable = 1uz << 0,
-    //! Enable wait-monitoring of the coprocessor after task switching.
-    monitor_coprocessor = 1uz << 1,
-    //! Emulate floating point coprocessor.
-    emulation = 1uz << 2,
-    //! Marks that a task switch has occurred.
-    task_switched = 1uz << 3,
-    //! Marks Intel 387 DX math coprocessor as available
-    extension_type = 1uz << 4,
-    //! Numeric error handling mode.
-    numeric_error = 1uz << 5,
-    //! Disable writing to read-only marked memory.
-    write_protect = 1uz << 16,
-    //! Enable Ring-3 alignment checks
-    alignment_check = 1uz << 18,
-    //! Disable write through
-    not_write_through = 1uz << 29,
-    //! Disable caching of memory accesses
-    cache_disable = 1uz << 30,
-    //! Enable paging
-    paging = 1uz << 31
-  };
-
-  enum struct cr3_flags : std::uint64_t
-  {
-    page_level_write_through = 1uz << 0,
-    page_level_cache_disable = 1uz << 1,
-  };
-}  // namespace arch::cpu
-
-namespace kstd::ext
-{
-  template<>
-  struct is_bitfield_enum<arch::cpu::cr0_flags> : std::true_type
-  {
-  };
-
-  template<>
-  struct is_bitfield_enum<arch::cpu::cr3_flags> : std::true_type
-  {
-  };
-}  // namespace kstd::ext
-
-namespace arch::cpu
-{
-  //! A mixin for flag-oriented control registers.
-  //!
-  //! This mixin provides additional functionality for flag-oriented, or partially flag-oriented, control registers. A
-  //! control register is flag-oriented, if it comprises a bitfield and zero or more additional non-bitfield parts.
-  //!
-  //! @tparam Derived The class deriving from this mixin.
-  //! @tparam ValueType The value type of the class deriving from this mixin.
-  template<typename Derived, typename ValueType, typename = void>
-  struct control_register_with_flags
-  {
-  private:
-    constexpr control_register_with_flags() noexcept = default;
-    friend Derived;
-  };
-
-  //! @copydoc control_register_with_flags
-  //!
-  //! @note This specialization provides the implementation for the case in which the value type of the control register
-  //! is an enum.
-  template<typename Derived, typename ValueType>
-  struct control_register_with_flags<Derived, ValueType, std::enable_if_t<kstd::ext::bitfield_enum<ValueType>>>
-  {
-    //! The type of the flags used by this control register
-    using flags = ValueType;
-
-    //! Set one or more flags in this control register.
-    //!
-    //! @warning This function is to be considered **UNSAFE**. Setting flags in a control register may lead to
-    //! unexpected CPU behavior if the prerequisites imposed by the CPU specification are not fulfilled. This function
-    //! will perform no additional checks, and may, by extension, crash the system.
-    //!
-    //! @param value One or a combination of flags to be set in the control register.
-    auto static set(ValueType value) -> void
-    {
-      auto current = Derived::read();
-      current |= value;
-      Derived::write(current);
-    }
-
-    //! Clear one or more flags in this control register.
-    //!
-    //! @warning This function is to be considered **UNSAFE**. Clearing flags in a control register may lead to
-    //! unexpected CPU behavior if the prerequisites imposed by the CPU specification are not fulfilled. This function
-    //! will perform no additional checks, and may, by extension, crash the system.
-    //!
-    //! @param value One or a combination of flags to be cleared in the control register.
-    auto static clear(ValueType value) -> void
-    {
-      auto current = Derived::read();
-      current &= ~value;
-      Derived::write(current);
-    }
-  };
-
-  //! A CPU control register.
-  //!
-  //! CPU control registers are used to configure builtin features of the CPU, for example memory protection and FPU
-  //! error reporting. Writing to a control register is inherently dangerous, since a misconfiguration can leave the CPU
-  //! in an invalid/undefined state.
-  template<typename ValueType, auto AssemblerTemplates>
-  struct control_register : control_register_with_flags<control_register<ValueType, AssemblerTemplates>, ValueType>
-  {
-    //! Read the current value of the control register.
-    //!
-    //! @return The currently set value of the control register.
-    [[nodiscard]] auto static read() -> ValueType
-    {
-      auto value = ValueType{};
-      asm volatile((AssemblerTemplates->first) : "=r"(value));
-      return value;
-    }
-
-    //! Write a new value to the control register.
-    //!
-    //! @warning This function should be considered **UNSAFE**. Writing values to a control register may lead to
-    //! unexpected CPU behavior if the prerequisites imposed by the CPU specification are not fulfilled. This function
-    //! will perform no additional checks, and may, by extension, crash the system.
-    //!
-    //! @param value The new value to write to the control register.
-    auto static write(ValueType value) -> void
-    {
-      asm volatile((AssemblerTemplates->second) : : "r"(value));
-    }
-  };
-
-  //! The value type of the CR3 control register.
-  //!
-  //! The CR3 control register holds the root configuration of the virtual memory protection mechanism. It contains the
-  //! page aligned physical address of the root page map, as well as the root paging configuration flags.
-  struct cr3_value
-  {
-    //! Contstruct a 0-value CR3 value.
-    constexpr cr3_value() = default;
-
-    //! Construct a CR3 value using the given root page map address and flags.
-    //!
-    //! @param address The physical address of the root page map
-    //! @param flags The root configuration flags of the paging system.
-    constexpr cr3_value(kapi::memory::physical_address address, cr3_flags flags = static_cast<cr3_flags>(0))
-        : m_flags{static_cast<std::uint64_t>(flags)}
-        , m_address{static_cast<std::uint64_t>(address.raw())}
-    {}
-
-    //! Extract the physical address of the root page map from this value.
-    //!
-    //! @return The physical address of the root page map.
-    [[nodiscard]] constexpr auto address() const -> kapi::memory::physical_address
-    {
-      constexpr auto address_shift = 12uz;
-      return kapi::memory::physical_address{m_address << address_shift};
-    }
-
-    //! Encode the frame aligned physical address of the root page map into this value.
-    //!
-    //! @param frame The frame containing a PML4.
-    constexpr auto frame(kapi::memory::frame frame) -> void
-    {
-      m_address = static_cast<std::uint64_t>(frame.number());
-    }
-
-    //! Extract the root paging configuration flags from this value.
-    //!
-    //! @return The root paging configuration flags.
-    [[nodiscard]] constexpr auto flags() const -> cr3_flags
-    {
-      return static_cast<cr3_flags>(m_flags);
-    }
-
-    //! Encode the root paging configuration flags into this value.
-    //!
-    //! @param flags The root paging configuration flags.
-    constexpr auto flags(cr3_flags flags) -> void
-    {
-      m_flags = static_cast<std::uint64_t>(flags);
-    }
-
-    //! Add the given flags to the current set of encoded root configuration flags of this value.
-    //!
-    //! @param flags The root configuration flags to add.
-    //! @return A reference to this value.
-    constexpr auto operator|=(cr3_flags flags) -> cr3_value &
-    {
-      m_flags |= static_cast<std::uint64_t>(flags);
-      return *this;
-    }
-
-    //! Mask the root configuration flags of this value.
-    //!
-    //! @param mask The mask to apply to the root configuration flags.
-    //! @return A reference to this value.
-    constexpr auto operator&=(cr3_flags mask) -> cr3_value &
-    {
-      m_flags &= static_cast<std::uint64_t>(mask);
-      return *this;
-    }
-
-  private:
-    //! Reserved bits.
-    std::uint64_t : 3;
-    //! The root paging configuration flags.
-    std::uint64_t m_flags : 2 {};
-    //! Reserved bits.
-    std::uint64_t : 7;
-    //! The page aligned physical address of the root page map.
-    std::uint64_t m_address : 52 {};
-  };
-
-  static_assert(sizeof(cr3_value) == sizeof(std::uint64_t));
-
-}  // namespace arch::cpu
-
-#endif
\ No newline at end of file
diff --git a/arch/x86_64/include/arch/cpu/global_descriptor_table.hpp b/arch/x86_64/include/arch/cpu/global_descriptor_table.hpp
deleted file mode 100644
index b17c509..0000000
--- a/arch/x86_64/include/arch/cpu/global_descriptor_table.hpp
+++ /dev/null
@@ -1,91 +0,0 @@
-#ifndef TEACHOS_X86_64_GLOBAL_DESCRIPTOR_TABLE_HPP
-#define TEACHOS_X86_64_GLOBAL_DESCRIPTOR_TABLE_HPP
-
-#include <arch/cpu/segment_descriptor.hpp>
-
-#include <kapi/memory.hpp>
-
-#include <algorithm>
-#include <array>
-#include <bit>
-#include <concepts>
-#include <cstddef>
-#include <cstdint>
-#include <utility>
-
-namespace arch::cpu
-{
-
-  template<std::size_t Size>
-  struct global_descriptor_table;
-
-  struct [[gnu::packed]] global_descriptor_table_pointer
-  {
-    template<std::size_t GdtSize>
-    global_descriptor_table_pointer(global_descriptor_table<GdtSize> const & gdt)
-        : size{GdtSize * sizeof(segment_descriptor) - 1}
-        , address{kapi::memory::physical_address{std::bit_cast<std::uintptr_t>(&gdt)}.raw()}
-    {}
-
-    auto load() -> void
-    {
-      asm volatile("lgdt %0" : : "m"(*this));
-    }
-
-    std::uint16_t size{};
-    std::uint64_t address{};
-  };
-
-  static_assert(sizeof(global_descriptor_table_pointer) == sizeof(std::uint16_t) + sizeof(std::uint64_t));
-
-  template<std::size_t SizeInBytes>
-  struct global_descriptor_table
-  {
-    template<std::derived_from<segment_descriptor>... SegmentDescriptors>
-    constexpr global_descriptor_table(SegmentDescriptors const &... descriptors)
-        : m_descriptors{}
-    {
-      auto descriptor_data = std::array{
-        std::pair{std::bit_cast<std::byte const *>(&descriptors), sizeof(descriptors)}
-        ...
-      };
-      auto written_size = 0uz;
-      std::ranges::for_each(descriptor_data, [&written_size, this](auto entry) {
-        std::ranges::copy(entry.first, entry.first + entry.second, m_descriptors.begin() + written_size);
-        written_size += entry.second;
-      });
-    }
-
-    auto load(std::size_t code_segment_index, std::size_t data_segment_index) const -> void
-    {
-      auto pointer = global_descriptor_table_pointer{*this};
-      pointer.load();
-
-      asm volatile("push %0\n"
-                   "lea 1f(%%rip), %%rax\n"
-                   "push %%rax\n"
-                   "lretq\n"
-                   "1:\n"
-                   "mov %1, %%rax\n"
-                   "mov %%rax, %%ss\n"
-                   "mov %%rax, %%ds\n"
-                   "mov %%rax, %%es\n"
-                   "mov %%rax, %%fs\n"
-                   "mov %%rax, %%gs\n"
-                   :
-                   : "X"(code_segment_index * sizeof(segment_descriptor)),
-                     "X"(data_segment_index * sizeof(segment_descriptor))
-                   : "rax");
-    }
-
-  private:
-    std::array<std::byte, SizeInBytes> m_descriptors;
-  };
-
-  template<std::derived_from<segment_descriptor>... SegmentDescriptors>
-  global_descriptor_table(SegmentDescriptors const &... descriptors)
-      -> global_descriptor_table<(sizeof(SegmentDescriptors) + ...)>;
-
-}  // namespace arch::cpu
-
-#endif
\ No newline at end of file
diff --git a/arch/x86_64/include/arch/cpu/initialization.hpp b/arch/x86_64/include/arch/cpu/initialization.hpp
deleted file mode 100644
index 564c544..0000000
--- a/arch/x86_64/include/arch/cpu/initialization.hpp
+++ /dev/null
@@ -1,12 +0,0 @@
-#ifndef TEACHOS_ARCH_X86_64_CPU_INITIALIZATION_HPP
-#define TEACHOS_ARCH_X86_64_CPU_INITIALIZATION_HPP
-
-namespace arch::cpu
-{
-  auto initialize_descriptors() -> void;
-
-  auto initialize_legacy_interrupts() -> void;
-
-}  // namespace arch::cpu
-
-#endif
diff --git a/arch/x86_64/include/arch/cpu/interrupts.hpp b/arch/x86_64/include/arch/cpu/interrupts.hpp
deleted file mode 100644
index 6162f56..0000000
--- a/arch/x86_64/include/arch/cpu/interrupts.hpp
+++ /dev/null
@@ -1,116 +0,0 @@
-#ifndef TEACHOS_X86_64_CPU_INTERRUPTS_HPP
-#define TEACHOS_X86_64_CPU_INTERRUPTS_HPP
-
-#include <arch/cpu/segment_selector.hpp>
-
-#include <kapi/memory.hpp>
-
-#include <array>
-#include <cstdint>
-#include <type_traits>
-
-namespace arch::cpu
-{
-
-  //! The types of supported gates.
-  enum struct gate_type : std::uint8_t
-  {
-    //! A gate entered through the @p INT instruction.
-    interrupt_gate = 0b1110,
-    //! A gate entered via an exception.
-    trap_gate = 0b1111,
-  };
-
-  struct alignas(std::uint64_t) gate_descriptor
-  {
-    //! The lowest 16 bits of the address of this gate's handler function.
-    std::uint16_t offset_low : 16;
-    //! The code segment used when handling the respective interrupt.
-    segment_selector m_code_segment;
-    //! The index into the Interrupt Stack Table naming the stack to use.
-    std::uint8_t interrupt_stack_table_selector : 3;
-    //! Reserved
-    std::uint8_t : 5;
-    //! The type of this gate.
-    enum gate_type gate_type : 4;
-    //! Reserved
-    std::uint8_t : 1;
-    //! The privilege level required to enter through this gate.
-    std::uint8_t descriptor_privilege_level : 2;
-    //! Whether this gate is present or not.
-    std::uint8_t present : 1;
-    //! The middle 16 bits of the address of this gate's handler function.
-    std::uint16_t offset_middle : 16;
-    //! The highest 32 bits of the address of this gate's handler function.
-    std::uint32_t offset_high : 32;
-    //! Reserved
-    std::uint32_t : 32;
-  };
-
-  static_assert(sizeof(gate_descriptor) == 2 * sizeof(std::uint64_t));
-  static_assert(std::is_aggregate_v<gate_descriptor>);
-
-  //! The stack frame as established by the low-level assembly interrupt stubs.
-  //!
-  //! @note The layout of this struct is reverse than what would reasonably be expected. The reason for this reversal is
-  //! that fact that it represents a stack frame. Stack frames on x86_64 grow towards lower addresses, meaning the first
-  //! item on the stack is the last item in C++ memory layout order.
-  struct interrupt_frame
-  {
-    struct
-    {
-      std::uint64_t r15{};
-      std::uint64_t r14{};
-      std::uint64_t r13{};
-      std::uint64_t r12{};
-      std::uint64_t r11{};
-      std::uint64_t r10{};
-      std::uint64_t r9{};
-      std::uint64_t r8{};
-      std::uint64_t rdi{};
-      std::uint64_t rsi{};
-      std::uint64_t rbp{};
-      std::uint64_t rdx{};
-      std::uint64_t rcx{};
-      std::uint64_t rbx{};
-      std::uint64_t rax{};
-    } handler_saved;
-
-    struct
-    {
-      std::uint64_t number{};
-      std::uint64_t error_code{};
-    } interrupt;
-
-    struct
-    {
-      kapi::memory::linear_address rip{};
-      std::uint64_t cs{};
-      std::uint64_t rflags{};
-      kapi::memory::linear_address rsp{};
-      std::uint64_t ss{};
-    } cpu_saved;
-  };
-
-  struct interrupt_descriptor_table
-  {
-    interrupt_descriptor_table() noexcept;
-
-    auto load() const -> void;
-
-  private:
-    std::array<gate_descriptor, 256> m_descriptors{};
-  };
-
-  struct [[gnu::packed]] interrupt_descriptor_table_register
-  {
-    std::uint16_t limit;
-    gate_descriptor const * base;
-
-    auto load() const -> void;
-    auto static read() -> interrupt_descriptor_table_register;
-  };
-
-}  // namespace arch::cpu
-
-#endif
\ No newline at end of file
diff --git a/arch/x86_64/include/arch/cpu/legacy_pic.hpp b/arch/x86_64/include/arch/cpu/legacy_pic.hpp
deleted file mode 100644
index 56ca9c4..0000000
--- a/arch/x86_64/include/arch/cpu/legacy_pic.hpp
+++ /dev/null
@@ -1,19 +0,0 @@
-#ifndef TEACHOS_X86_64_CPU_LEGACY_PIC_HPP
-#define TEACHOS_X86_64_CPU_LEGACY_PIC_HPP
-
-#include <arch/device_io/port_io.hpp>
-
-#include <cstdint>
-
-namespace arch::cpu
-{
-  using pic_master_control_port = io::port<0x20, std::uint8_t, io::port_read, io::port_write>;
-  using pic_master_data_port = io::port<0x21, std::uint8_t, io::port_read, io::port_write>;
-  using pic_slave_control_port = io::port<0xa0, std::uint8_t, io::port_read, io::port_write>;
-  using pic_slave_data_port = io::port<0xa1, std::uint8_t, io::port_read, io::port_write>;
-
-  constexpr auto pic_end_of_interrupt = std::uint8_t{0x20};
-
-}  // namespace arch::cpu
-
-#endif
\ No newline at end of file
diff --git a/arch/x86_64/include/arch/cpu/model_specific_register.hpp b/arch/x86_64/include/arch/cpu/model_specific_register.hpp
deleted file mode 100644
index bd4aff9..0000000
--- a/arch/x86_64/include/arch/cpu/model_specific_register.hpp
+++ /dev/null
@@ -1,151 +0,0 @@
-#ifndef TEACHOS_X86_64_CPU_MODEL_SPECIFIC_REGISTER_HPP
-#define TEACHOS_X86_64_CPU_MODEL_SPECIFIC_REGISTER_HPP
-
-// IWYU pragma: private, include <x86_64/cpu/registers.hpp>
-
-#include <kstd/ext/bitfield_enum>
-
-#include <bit>
-#include <cstdint>
-#include <type_traits>
-
-namespace arch::cpu
-{
-
-  //! The flags of the IA32_EFER (Extended Features Enable Register) MSR.
-  enum struct ia32_efer_flags : std::uint64_t
-  {
-    //! Enable the syscall and sysret instructions.
-    syscall_enable = 1uz << 0,
-    //! Enable IA-32e mode operation.
-    ia32e_mode_enable = 1uz << 8,
-    //! Indicates IA-32e mode is active (read-only)
-    ia32e_mode_active = 1uz << 10,
-    //! Enable the use of the NX page table bit.
-    execute_disable_bit_enable = 1uz << 11,
-  };
-
-}  // namespace arch::cpu
-
-namespace kstd::ext
-{
-
-  template<>
-  struct is_bitfield_enum<arch::cpu::ia32_efer_flags> : std::true_type
-  {
-  };
-
-}  // namespace kstd::ext
-
-namespace arch::cpu
-{
-  //! The MSR number for the IA32_EFER MSR
-  constexpr auto ia32_efer_number = 0xC000'0080u;
-
-  //! A mixin for flag-oriented model specific registers.
-  //!
-  //! This mixin provides additional functionality for a flag-oriented model specific register. A models specific
-  //! register is flag-oriented, if it comprises a single field of bitfield.
-  //!
-  //! @tparam Derived The class deriving from this mixin.
-  //! @tparam ValueType The value type of the class deriving from this mixin.
-  template<typename Derived, typename ValueType, typename = void>
-  struct model_specific_register_with_flags
-  {
-  private:
-    constexpr model_specific_register_with_flags() noexcept = default;
-    friend Derived;
-  };
-
-  //! @copydoc model_specific_register_with_flags
-  //!
-  //! @note This specialization provides the implementation for the case in which the value type of the model specific
-  //! register is a bitfield enum.
-  template<typename Derived, typename ValueType>
-  struct model_specific_register_with_flags<Derived, ValueType, std::enable_if_t<kstd::ext::bitfield_enum<ValueType>>>
-  {
-    //! The of the flags used by this model specific register.
-    using flags = ValueType;
-
-    //! Set one or more flags in this model specific register.
-    //!
-    //! @warning This function is to be considered **UNSAFE**. Setting flags in a model specific register may lead to
-    //! unexpected CPU behavior if the prerequisites imposed by the CPU specification are not fulfilled. This function
-    //! will perform no additional checks, and may, by extension, crash the system.
-    //!
-    //! @param flag One or a combination of flags to be set in the model specific register.
-    auto static set(flags flag) -> void
-    {
-      auto current = Derived::read();
-      current |= flag;
-      Derived::write(current);
-    }
-
-    //! Clear one or more flags in this model specific register.
-    //!
-    //! @warning This function is to be considered **UNSAFE**. Clearing flags in a model specific register may lead to
-    //! unexpected CPU behavior if the prerequisites imposed by the CPU specification are not fulfilled. This function
-    //! will perform no additional checks, and may, by extension, crash the system.
-    //!
-    //! @param flag One or a combination of flags to be cleared in the model specific register.