x86_64: move files out of the way

50 files changed, 3223 insertions, 0 deletions

diff --git a/arch/x86_64/pre/include/arch/context_switching/interrupt_descriptor_table/gate_descriptor.hpp b/arch/x86_64/pre/include/arch/context_switching/interrupt_descriptor_table/gate_descriptor.hpp
new file mode 100644
index 0000000..07110c8
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/context_switching/interrupt_descriptor_table/gate_descriptor.hpp
@@ -0,0 +1,69 @@
+#ifndef TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_INTERRUPT_DESCRIPTOR_TABLE_GATE_DESCRIPTOR_HPP
+#define TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_INTERRUPT_DESCRIPTOR_TABLE_GATE_DESCRIPTOR_HPP
+
+#include "arch/context_switching/interrupt_descriptor_table/idt_flags.hpp"
+#include "arch/context_switching/interrupt_descriptor_table/ist_offset.hpp"
+#include "arch/context_switching/interrupt_descriptor_table/segment_selector.hpp"
+
+#include <bitset>
+#include <cstdint>
+
+namespace teachos::arch::context_switching::interrupt_descriptor_table
+{
+  __extension__ typedef __int128 int128_t;
+  __extension__ typedef unsigned __int128 uint128_t;
+
+  /**
+   * @brief Defines helper function for all states and the actual data the gate descriptor can have.
+   */
+  struct [[gnu::packed]] gate_descriptor
+  {
+    /**
+     * @brief Default Constructor.
+     */
+    gate_descriptor() = default;
+
+    /**
+     * @brief Constructor.
+     *
+     * @note Created gate descriptor copies the given bytes into these components ending with a 32 bit reserved
+     * field that has to be used, because the 64-bit gate descriptor needs to be big enough for two 32-bit gate
+     * descriptor.
+     * - 16 bit Segment Selector
+     * - 3 bit Interrupt Stack Table Offset
+     * - 8 bit Type and Flags
+     * - 64 bit Offset
+     *
+     * @param flags Copies the bits set from the given data into the individual components of a gate
+     * descriptor.
+     */
+    explicit gate_descriptor(uint128_t flags);
+
+    /**
+     * @brief Constructor.
+     *
+     * @param selector, ist, flags, offset Copies the bits set from the given data into the individual components of
+     * a gate descriptor.
+     */
+    gate_descriptor(segment_selector selector, ist_offset ist, idt_flags flags, uint64_t offset);
+
+    /**
+     * @brief Allows to compare the underlying bits of two instances.
+     *
+     * @param other Other instance that we want to compare with.
+     * @return Whether the underlying set bits of both types are the same.
+     */
+    auto operator==(gate_descriptor const & other) const -> bool = default;
+
+  private:
+    // The order in private variables starts for the first variable being the rightmost bit.
+    uint16_t _offset_1 = {};          ///< Lower 16 bits of handler function address (0 - 15)
+    segment_selector _selector = {};  ///< Segment selector (16 - 31)
+    ist_offset _ist = {};             ///< Interrupt Stack Table offset (32 - 39)
+    idt_flags _flags = {};            ///< Gate Type and Flags (40 - 47)
+    uint64_t _offset_2 : 48 = {};     ///< Upper 48 bits of handler function address (48 - 95)
+    uint32_t : 32;                    ///< Reserved field used to ensure this struct is 128 bits big (96 - 127)
+  };
+}  // namespace teachos::arch::context_switching::interrupt_descriptor_table
+
+#endif  // TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_INTERRUPT_DESCRIPTOR_TABLE_GATE_DESCRIPTOR_HPP
diff --git a/arch/x86_64/pre/include/arch/context_switching/interrupt_descriptor_table/idt_flags.hpp b/arch/x86_64/pre/include/arch/context_switching/interrupt_descriptor_table/idt_flags.hpp
new file mode 100644
index 0000000..5104c36
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/context_switching/interrupt_descriptor_table/idt_flags.hpp
@@ -0,0 +1,81 @@
+
+#ifndef TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_INTERRUPT_DESCRIPTOR_TABLE_IDT_FLAGS_HPP
+#define TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_INTERRUPT_DESCRIPTOR_TABLE_IDT_FLAGS_HPP
+
+#include <bitset>
+#include <cstdint>
+
+namespace teachos::arch::context_switching::interrupt_descriptor_table
+{
+  /**
+   * @brief Defines helper function for all states that the access byte field of a segment descriptor can
+   * have.
+   */
+  struct [[gnu::packed]] idt_flags
+  {
+    /**
+     * @brief Possible set bits in our underlying bits and the meaning when they are set.
+     */
+    enum bitset : uint8_t
+    {
+      INTERRUPT_GATE = 0b01110,  ///< The actual type of gate segment is a interrupt gate.
+      TRAP_GATE = 0b01111,       ///< The actual type of gate segment is a trap gate.
+      DESCRIPTOR_LEVEL_KERNEL =
+          0U << 5U,  ///< Highest privileged level used by the kernel to allow for full access of resources.
+      DESCRIPTOR_LEVEL_ADMIN =
+          1U << 5U,  ///< Restricts access to own application and thoose of lower privilege. Should only be used if more
+                     ///< than two privilege levels are required, otherwise using Level 3 and Level 0 is recommended.
+      DESCRIPTOR_LEVEL_PRIVILEGED_USER =
+          2U << 5U,  ///< Restricts access to own application and thoose of lower privilege. Should only be used if more
+                     ///< than two privilege levels are required, otherwise using Level 3 and Level 0 is recommended.
+      DESCRIPTOR_LEVEL_USER = 3U << 5U,  ///< Restricts access to only application and their specific memory.
+      PRESENT = 1U << 7U,                ///< Present bit; Allows an entry to refer to a valid segment.
+                                         ///< Must be set (1) for any valid segment.
+    };
+
+    /**
+     * @brief Default Constructor.
+     */
+    idt_flags() = default;
+
+    /**
+     * @brief Constructor.
+     *
+     * @param flags Allows to set flags for the access byte field using the unscoped enum contained in this class, used
+     * to allow for direct integer conversion. This value is saved and can later be used to check whether certain flags
+     * are enabled or not using contains_flags method.
+     */
+    idt_flags(uint8_t flags);
+
+    /**
+     * @brief Checks if the given std::bitset is a subset or equivalent to the underlying data.
+     *
+     * @note Meaning that all bits that are set in the given std::bitset also have to be set in the underlyng
+     * data. Any additional bits that are set are not relevant.
+     *
+     * @param other Flags that we want to compare against and check if the underlying data has the same bits set.
+     * @return Whether the given flags are a subset or equivalent with the underlying data.
+     */
+    auto contains_flags(std::bitset<8U> other) const -> bool;
+
+    /**
+     * @brief Allows to compare the underlying bits of two instances.
+     *
+     * @param other Other instance that we want to compare with.
+     * @return Whether the underlying set bits of both types are the same.
+     */
+    auto operator==(idt_flags const & other) const -> bool = default;
+
+    /**
+     * @brief Combines all bits that are set in the std::bitset flags with the bits already set in the underlying data.
+     *
+     * @param other Additional bits that should be set.
+     */
+    auto operator|=(std::bitset<8U> other) -> void;
+
+  private:
+    uint8_t _flags = {};  ///< Underlying bits used to read the flags from.
+  };
+}  // namespace teachos::arch::context_switching::interrupt_descriptor_table
+
+#endif  // TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_INTERRUPT_DESCRIPTOR_TABLE_IDT_FLAGS_HPP
\ No newline at end of file
diff --git a/arch/x86_64/pre/include/arch/context_switching/interrupt_descriptor_table/interrupt_descriptor_table.hpp b/arch/x86_64/pre/include/arch/context_switching/interrupt_descriptor_table/interrupt_descriptor_table.hpp
new file mode 100644
index 0000000..b388e0e
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/context_switching/interrupt_descriptor_table/interrupt_descriptor_table.hpp
@@ -0,0 +1,24 @@
+#ifndef TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_INTERRUPT_DESCRIPTOR_TABLE_INTERRUPT_DESCRIPTOR_TABLE_HPP
+#define TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_INTERRUPT_DESCRIPTOR_TABLE_INTERRUPT_DESCRIPTOR_TABLE_HPP
+
+#include "arch/context_switching/interrupt_descriptor_table/interrupt_descriptor_table_pointer.hpp"
+
+namespace teachos::arch::context_switching::interrupt_descriptor_table
+{
+  /**
+   * @brief Updates the IDTR with the created interrupt descriptor table. If it has not been created yet this
+   * method will create it.
+   */
+  auto update_interrupt_descriptor_table_register() -> void;
+
+  /**
+   * @brief Creates the interrupt descriptor table, with the minimum required configuration. If this method is called
+   * more than once, the previously created instance is returned instead.
+   *
+   * @return Reference to the created interrupt_descriptor_table.
+   */
+  auto get_or_create_interrupt_descriptor_table() -> interrupt_descriptor_table &;
+
+}  // namespace teachos::arch::context_switching::interrupt_descriptor_table
+
+#endif  // TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_INTERRUPT_DESCRIPTOR_TABLE_INTERRUPT_DESCRIPTOR_TABLE_HPP
diff --git a/arch/x86_64/pre/include/arch/context_switching/interrupt_descriptor_table/interrupt_descriptor_table_pointer.hpp b/arch/x86_64/pre/include/arch/context_switching/interrupt_descriptor_table/interrupt_descriptor_table_pointer.hpp
new file mode 100644
index 0000000..7fe933b
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/context_switching/interrupt_descriptor_table/interrupt_descriptor_table_pointer.hpp
@@ -0,0 +1,40 @@
+#ifndef TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_INTERRUPT_DESCRIPTOR_TABLE_INTERRUPT_DESCRIPTOR_TABLE_POINTER_HPP
+#define TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_INTERRUPT_DESCRIPTOR_TABLE_INTERRUPT_DESCRIPTOR_TABLE_POINTER_HPP
+
+#include "arch/context_switching/interrupt_descriptor_table/gate_descriptor.hpp"
+#include "arch/stl/vector.hpp"
+
+namespace teachos::arch::context_switching::interrupt_descriptor_table
+{
+  using interrupt_descriptor_table = stl::vector<gate_descriptor>;
+
+  /**
+   * @brief Represents a pointer to the Interrupt Descriptor Table (IDT).
+   *
+   * This structure is used to store the base address and length of the IDT.
+   */
+  struct [[gnu::packed]] interrupt_descriptor_table_pointer
+  {
+    /**
+     * @brief Default constructor.
+     */
+    interrupt_descriptor_table_pointer() = default;
+
+    /**
+     * @brief Constructor.
+     */
+    interrupt_descriptor_table_pointer(uint16_t table_length, gate_descriptor * address);
+
+    /**
+     * @brief Defaulted three-way comparsion operator.
+     */
+    auto operator<=>(interrupt_descriptor_table_pointer const & other) const -> std::strong_ordering = default;
+
+  private:
+    uint16_t table_length = {};      ///< The amount of segment descriptor entries in the global descriptor table - 1.
+    gate_descriptor * address = {};  ///< Non-owning pointer to the IDT base address.
+  };
+
+}  // namespace teachos::arch::context_switching::interrupt_descriptor_table
+
+#endif  // TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_INTERRUPT_DESCRIPTOR_TABLE_INTERRUPT_DESCRIPTOR_TABLE_POINTER_HPP
diff --git a/arch/x86_64/pre/include/arch/context_switching/interrupt_descriptor_table/ist_offset.hpp b/arch/x86_64/pre/include/arch/context_switching/interrupt_descriptor_table/ist_offset.hpp
new file mode 100644
index 0000000..e45bcf4
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/context_switching/interrupt_descriptor_table/ist_offset.hpp
@@ -0,0 +1,45 @@
+#ifndef TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_INTERRUPT_DESCRIPTOR_TABLE_IST_OFFSET_HPP
+#define TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_INTERRUPT_DESCRIPTOR_TABLE_IST_OFFSET_HPP
+
+#include <bitset>
+#include <cstdint>
+
+namespace teachos::arch::context_switching::interrupt_descriptor_table
+{
+  /**
+   * @brief Defines helper function for all states that the interrupt stack table offset field of a gate descriptor can
+   * have. Is automatically increased to one byte in size, to include the following 5 reserved bits in the gate
+   * descriptor.
+   */
+  struct [[gnu::packed]] ist_offset
+  {
+    /**
+     * @brief Default Constructor.
+     */
+    ist_offset() = default;
+
+    /**
+     * @brief Constructor.
+     *
+     * @param offset Offset into the interrupt stack table. A value of of 0 means we do not switch stacks, whereas 1 - 7
+     * mean we switch to the n-th stack in the Interrupt Stack Table, contained in the TSS if the gate descriptor that
+     * contains this field is called.
+     */
+    ist_offset(uint8_t offset);
+
+    /**
+     * @brief Allows to compare the underlying set bits of two instances.
+     *
+     * @param other Other instance that we want to compare with.
+     * @return Whether the underlying set bits of both types are the same.
+     */
+    auto operator==(ist_offset const & other) const -> bool = default;
+
+  private:
+    uint8_t _ist : 3 = {};  ///< Offset into the interrupt stack table. A value of of 0 means we do not switch stacks,
+                            ///< whereas 1 - 7 mean we switch to the n-th stack in the Interrupt Stack Table, contained
+                            ///< in the TSS if the gate descriptor that contains this field is called.
+  };
+}  // namespace teachos::arch::context_switching::interrupt_descriptor_table
+
+#endif  // TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_INTERRUPT_DESCRIPTOR_TABLE_IST_OFFSET_HPP
diff --git a/arch/x86_64/pre/include/arch/context_switching/interrupt_descriptor_table/segment_selector.hpp b/arch/x86_64/pre/include/arch/context_switching/interrupt_descriptor_table/segment_selector.hpp
new file mode 100644
index 0000000..2a7704e
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/context_switching/interrupt_descriptor_table/segment_selector.hpp
@@ -0,0 +1,105 @@
+#ifndef TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_INTERRUPT_DESCRIPTOR_TABLE_SEGMENT_SELECTOR_HPP
+#define TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_INTERRUPT_DESCRIPTOR_TABLE_SEGMENT_SELECTOR_HPP
+
+#include <bitset>
+#include <cstdint>
+
+namespace teachos::arch::context_switching::interrupt_descriptor_table
+{
+  /**
+   * @brief Represents a segment selector in the x86_64 architecture, which points to a valid code segment in the global
+   * descriptor table.
+   *
+   * A segment selector is a 16-bit identifier used to select a segment descriptor
+   * from the Global Descriptor Table (GDT) or the Local Descriptor Table (LDT).
+   * It contains an index, a table indicator (TI), and a requested privilege level (RPL).
+   */
+  struct [[gnu::packed]] segment_selector
+  {
+    /**
+     * @brief Possible set bits in our underlying bits and the meaning when they are set.
+     */
+    enum bitset : uint8_t
+    {
+      REQUEST_LEVEL_KERNEL =
+          0U << 0U,  ///< Highest privileged level used by the kernel to allow for full access of resources.
+      REQUEST_LEVEL_ADMIN =
+          1U << 0U,  ///< Restricts access to own application and thoose of lower privilege. Should only be used if more
+                     ///< than two privilege levels are required, otherwise using Level 3 and Level 0 is recommended.
+      REQUEST_LEVEL_PRIVILEGED_USER =
+          2U << 0U,  ///< Restricts access to own application and thoose of lower privilege. Should only be used if more
+                     ///< than two privilege levels are required, otherwise using Level 3 and Level 0 is recommended.
+      REQUEST_LEVEL_USER = 3U << 0U,      ///< Restricts access to only application and their specific memory.
+      LOCAL_DESCRIPTOR_TABLE = 1U << 2U,  ///< Wheter the index referes to an entry in the local or global descriptor
+                                          ///< table. If enabled the index points to a local descriptor table, if it is
+                                          ///< cleared it referes to a global descriptor table instead.
+    };
+
+    /**
+     * @brief Default constructor.
+     */
+    segment_selector() = default;
+
+    /**
+     * @brief Constructor.
+     *
+     * @param index Index into the local or global descriptor table. Processor multiplies the index value by 8 (number
+     * of bytes in 32-bit segment descriptor) and adds the result to the base GDT or LDT address.
+     * @param flags Allows to set flags for the flags field using the unscoped enum contained in this class, used to
+     * allow for direct integer conversion.
+     */
+    constexpr segment_selector(uint16_t index, uint8_t flags)
+        : _flags(flags)
+        , _index(index)
+    {
+      // Nothing to do.
+    }
+
+    /**
+     * @brief Checks if the given std::bitset is a subset or equivalent to the underlying data.
+     *
+     * @note Meaning that all bits that are set in the given std::bitset also have to be set in the underlyng
+     * data. Any additional bits that are set are not relevant.
+     *
+     * @param other Flags that we want to compare against and check if the underlying data has the same bits set.
+     * @return Whether the given flags are a subset or equivalent with the underlying data.
+     */
+    auto contains_flags(std::bitset<3U> other) const -> bool;
+
+    /**
+     * @brief Gets the index into the global descriptor table or the local descriptor table this segment selector is
+     * pointing too.
+     *
+     * @return Underlying value of the index field, bit 3 - 16.
+     */
+    [[gnu::section(".user_text")]]
+    auto get_index() const -> uint16_t;
+
+    /**
+     * @brief Defaulted three-way comparsion operator.
+     */
+    auto operator<=>(segment_selector const & other) const -> std::strong_ordering = default;
+
+    /**
+     * @brief Combines all bits that are set in the std::bitset flags with the bits already set in the underlying data.
+     *
+     * @param other Additional bits that should be set.
+     */
+    auto operator|=(std::bitset<3U> other) -> void;
+
+    /**
+     * @brief Cast the underlying data into a combined 16-bit form, that contains all data.
+     *
+     * @return Underlying value combined into it's full size.
+     */
+    operator uint16_t() const;
+
+  private:
+    uint8_t _flags : 3 = {};  ///< Underlying bits used to read the flags from.
+    uint16_t _index : 13 =
+        {};  ///< Index into the local or global descriptor table. Processor multiplies the index value by 16 (number of
+             ///< bytes in segment descriptor) and adds the result to the base address.
+  };
+}  // namespace teachos::arch::context_switching::interrupt_descriptor_table
+
+#endif  // TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_INTERRUPT_DESCRIPTOR_TABLE_SEGMENT_SELECTOR_HPP
diff --git a/arch/x86_64/pre/include/arch/context_switching/main.hpp b/arch/x86_64/pre/include/arch/context_switching/main.hpp
new file mode 100644
index 0000000..f8477ea
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/context_switching/main.hpp
@@ -0,0 +1,51 @@
+#ifndef TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_MAIN_HPP
+#define TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_MAIN_HPP
+
+#include "arch/context_switching/interrupt_descriptor_table/interrupt_descriptor_table.hpp"
+#include "arch/context_switching/segment_descriptor_table/global_descriptor_table.hpp"
+
+namespace teachos::arch::context_switching
+{
+  /**
+   * @brief Contains the references to the tables required for context switching
+   */
+  struct descriptor_tables
+  {
+    segment_descriptor_table::global_descriptor_table & gdt;       ///< Reference to the global descriptor table.
+    interrupt_descriptor_table::interrupt_descriptor_table & idt;  ///< Reference to the interrupt descriptor table.
+  };
+
+  /**
+   * @brief Creates the Interrupt Descriptor Table and Global Descriptor Table as a static variable the first time this
+   * method is called and update IDTR and GDTR registers values.
+   *
+   * @note Subsequent calls after the first one, will simply return the previously created tables, but not update the
+   * registers again.
+   *
+   * @return References to the statically created Interrupt Descriptor and Global Descriptor Table.
+   */
+  auto initialize_descriptor_tables() -> descriptor_tables;
+
+  /**
+   * @brief Switches from the current Kernel Mode (Level 0) to User Mode (Level 3). Will simply use predefined Segment
+   * Selectors for the User Data and User Code Segment, which are Index 3 and 4 in the GDT respectively.
+   */
+  auto switch_to_user_mode() -> void;
+
+  /**
+   * @brief Switches from the current Code and Data Segment to the given Code and Data Segment.
+   *
+   * @note This method will additionally call initialize_descriptor_tables, to ensure the GDTR and IDTR have been setup
+   * correctly before attempting to switch the context. This switch is achieved using a far return, which will once
+   * executed call the given void function.
+   *
+   * @param data_segment Data Segment that the SS, DS; ES, FS and GS register will be set too.
+   * @param code_segment Code Segment that the CS register will be set too.
+   * @param return_function Function that will be called once the switch has been achieved.
+   */
+  auto switch_context(interrupt_descriptor_table::segment_selector data_segment,
+                      interrupt_descriptor_table::segment_selector code_segment, void (*return_function)()) -> void;
+
+}  // namespace teachos::arch::context_switching
+
+#endif  // TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_MAIN_HPP
diff --git a/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/access_byte.hpp b/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/access_byte.hpp
new file mode 100644
index 0000000..7450330
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/access_byte.hpp
@@ -0,0 +1,104 @@
+
+#ifndef TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_ACCESS_BYTE_HPP
+#define TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_ACCESS_BYTE_HPP
+
+#include <bitset>
+#include <cstdint>
+
+namespace teachos::arch::context_switching::segment_descriptor_table
+{
+  /**
+   * @brief Defines helper function for all states that the access byte field of a segment descriptor can
+   * have.
+   */
+  struct [[gnu::packed]] access_byte
+  {
+    /**
+     * @brief Possible set bits in our underlying bits and the meaning when they are set.
+     */
+    enum bitset : uint8_t
+    {
+      ACCESSED =
+          1U
+          << 0U,  ///< Whether the segment has been accessed since the last time the operating system has cleared the
+                  ///< flag. If enabled it has been accessed, otherwise it has not been accessed since the last clear.
+      WRITABLE = 1U << 1U,  ///< Indicates if the data segment is writable or not. If enabled the code segment allows
+                            ///< read and write access, otherwise only read access is possible.
+      READABLE = 1U << 1U,  ///< Indicates if the code segment is readable or not. If enabled the code segment allows
+                            ///< read and execute access, otherwise only executable access is possible.
+      CONFORMING =
+          1U << 2U,  ///< Indicates if the code is allowed to be executed by different access levels
+                     ///< (higher or lower) in code segments. If enabled the code segment allows access, otherwise
+                     ///< access from different privilege levels with throw a General-Protectione exception.
+      EXPAND_DOWN = 1U << 2U,   ///< Indicates if the expansion direction is up or down in data segments. If enabled the
+                                ///< data segment expands downwards, otherwise it expands upwards.
+      CODE_SEGMENT = 1U << 3U,  ///< Further defines the actual type of the segment. If enabled this segment is a code
+                                ///< segment, otherwise its a data segment.
+      LOCAL_DESCRIPTOR_TABLE = 2,  ///< The actual type of sytem segment is a local descriptor table.
+      TASK_STATE_SEGMENT_AVAILABLE =
+          9,  ///< The actual type of sytem segment is a task state segment that is still available.
+      TASK_STATE_SEGMENT_BUSY = 11,  ///< The actual type of sytem segment is a task state segment that is currently in
+                                     ///< use and therefore busy.
+      CALL_GATE = 11,                ///< The actual type of sytem segment is a call gate.
+      INTERRUPT_GATE = 14,           ///< The actual type of sytem segment is a interrupt gate.
+      TRAP_GATE = 15,                ///< The actual type of sytem segment is a trap gate.
+      CODE_OR_DATA_SEGMENT = 1U << 4U,  ///< Defines a system segment (if 0) or a code/data segment (if 1).
+      DESCRIPTOR_LEVEL_KERNEL =
+          0U << 5U,  ///< Highest privileged level used by the kernel to allow for full access of resources.
+      DESCRIPTOR_LEVEL_ADMIN =
+          1U << 5U,  ///< Restricts access to own application and thoose of lower privilege. Should only be used if more
+                     ///< than two privilege levels are required, otherwise using Level 3 and Level 0 is recommended.
+      DESCRIPTOR_LEVEL_PRIVILEGED_USER =
+          2U << 5U,  ///< Restricts access to own application and thoose of lower privilege. Should only be used if more
+                     ///< than two privilege levels are required, otherwise using Level 3 and Level 0 is recommended.
+      DESCRIPTOR_LEVEL_USER = 3U << 5U,  ///< Restricts access to only application and their specific memory.
+      PRESENT = 1U << 7U,                ///< Present bit; Allows an entry to refer to a valid segment.
+                                         ///< Must be set (1) for any valid segment.
+    };
+
+    /**
+     * @brief Default Constructor.
+     */
+    access_byte() = default;
+
+    /**
+     * @brief Constructor.
+     *
+     * @param flags Allows to set flags for the access byte field using the unscoped enum contained in this class, used
+     * to allow for direct integer conversion. This value is saved and can later be used to check whether certain flags
+     * are enabled or not using contains_flags method.
+     */
+    access_byte(uint8_t flags);
+
+    /**
+     * @brief Checks if the given std::bitset is a subset or equivalent to the underlying data.
+     *
+     * @note Meaning that all bits that are set in the given std::bitset also have to be set in the underlyng
+     * data. Any additional bits that are set are not relevant.
+     *
+     * @param other Flags that we want to compare against and check if the underlying data has the same bits set.
+     * @return Whether the given flags are a subset or equivalent with the underlying data.
+     */
+    auto contains_flags(std::bitset<8U> other) const -> bool;
+
+    /**
+     * @brief Allows to compare the underlying data of two instances.
+     *
+     * @param other Other instance that we want to compare with.
+     * @return Whether the underlying data of both types is the same.
+     */
+    auto operator==(access_byte const & other) const -> bool = default;
+
+    /**
+     * @brief Combines all bits that are set in the std::bitset flags with the bits already set in the underlying data.
+     *
+     * @param other Additional bits that should be set.
+     */
+    auto operator|=(std::bitset<8U> other) -> void;
+
+  private:
+    uint8_t _flags = {};  ///< Underlying bits used to read the flags from.
+  };
+}  // namespace teachos::arch::context_switching::segment_descriptor_table
+
+#endif  // TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_ACCESS_BYTE_HPP
\ No newline at end of file
diff --git a/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/gdt_flags.hpp b/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/gdt_flags.hpp
new file mode 100644
index 0000000..e24b988
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/gdt_flags.hpp
@@ -0,0 +1,93 @@
+#ifndef TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_GDT_FLAGS_HPP
+#define TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_GDT_FLAGS_HPP
+
+#include "arch/context_switching/segment_descriptor_table/segment_descriptor_type.hpp"
+
+#include <bitset>
+
+namespace teachos::arch::context_switching::segment_descriptor_table
+{
+  /**
+   * @brief Defines helper function for all states that the flags field of a segment descriptor can
+   * have.
+   */
+  struct [[gnu::packed]] gdt_flags
+  {
+    /**
+     * @brief Possible set bits in our underlying bits and the meaning when they are set.
+     */
+    enum bitset : uint8_t
+    {
+      LONG_MODE = 1U << 1U,  ///< Defines in IA-32e mode (64-bit code and 32-bit compatability mode) if the segment
+                             ///< contains 64-bit code. Otherwise this bit should always be 0. Enable if instructions
+                             ///< are executed in 64-bit code, otherwise they are executed in compatability 32-bit mode.
+                             ///< If this bit is set the 3rd bit needs to be clear (0).
+      UPPER_BOUND = 1U << 2U,  ///< Specifies the upper bound of the segment for expand down data segment. Enable for 4
+                               ///< GiB, 4 KiB otherwise.
+      STACK_POINTER_SIZE = 1U << 2U,  ///< Specifies the size of the Stack Pointer (SP) for stack segments used for
+                                      ///< implicit stack operations. Enable for 32 bit, 16 bit otherwise.
+      DEFAULT_LENGTH = 1U << 2U,      ///< Indicates the default length for code segments with effective addresses and
+                                      ///< operands. Enable for 32 bit, 16 bit otherwise.
+      GRANULARITY = 1U << 3U,  ///< Indicates the size the Limit value in the segment descriptor is scaled by 1 Byte
+                               ///< blocks if the bit is not set or by 4 KiB blocks if the bit is set.
+    };
+
+    /**
+     * @brief Default Constructor.
+     */
+    gdt_flags() = default;
+
+    /**
+     * @brief Constructor.
+     *
+     * @param flags Allows to set flags for the flags field using the unscoped enum contained in this class, used to
+     * allow for direct integer conversion. This value is saved and can later be used to check whether certain flags are
+     * enabled or not using contains_flags method.
+     * @param limit Does not necessarily make sense in the gdt flags type, but because the flags alone are only 4 bit
+     * the type would still require the space for a complete bit. Therefore the 4 bit segment limit field before the
+     * flags field is included in this type to ensure we actually contain 8 bit of data.
+     */
+    gdt_flags(uint8_t flags, std::bitset<20U> limit);
+
+    /**
+     * @brief Checks if the given std::bitset is a subset or equivalent to the underlying data.
+     *
+     * @note Meaning that all bits that are set in the given std::bitset also have to be set in the underlyng
+     * data. Any additional bits that are set are not relevant.
+     *
+     * @param other Flags that we want to compare against and check if the underlying data has the same bits set.
+     * @return Whether the given flags are a subset or equivalent with the underlying data.
+     */
+    auto contains_flags(std::bitset<4U> other) const -> bool;
+
+    /**
+     * @brief Get part of the segment limit that is saved in the gdt flags. This does not necessarily make sense in this
+     * object, but it has to be included here because a struct can not be smaller than a full byte. Therefore we include
+     * the 4 bit segment limit field so that it results in a compelte byte with the addtional 4 bit of gdt flags.
+     *
+     * @return 4-bit limit segment
+     */
+    auto get_limit() const -> std::bitset<4U>;
+
+    /**
+     * @brief Allows to compare the underlying set bits of two instances.
+     *
+     * @param other Other instance that we want to compare with.
+     * @return Whether the underlying set bits of both types are the same.
+     */
+    auto operator==(gdt_flags const & other) const -> bool = default;
+
+    /**
+     * @brief Combines all bits that are set in the std::bitset flags with the bits already set in the underlying data.
+     *
+     * @param other Additional bits that should be set.
+     */
+    auto operator|=(std::bitset<4U> other) -> void;
+
+  private:
+    uint8_t _limit_2 : 4 = {};  ///< Second part of the limit field.
+    uint8_t _flags : 4 = {};    ///< Underlying bits used to read the flags from.
+  };
+}  // namespace teachos::arch::context_switching::segment_descriptor_table
+
+#endif  // TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_GDT_FLAGS_HPP
diff --git a/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/global_descriptor_table.hpp b/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/global_descriptor_table.hpp
new file mode 100644
index 0000000..44f2692
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/global_descriptor_table.hpp
@@ -0,0 +1,37 @@
+#ifndef TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_GLOBAL_DESCRIPTOR_TABLE_HPP
+#define TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_GLOBAL_DESCRIPTOR_TABLE_HPP
+
+#include "arch/context_switching/segment_descriptor_table/global_descriptor_table_pointer.hpp"
+#include "arch/context_switching/segment_descriptor_table/task_state_segment.hpp"
+
+namespace teachos::arch::context_switching::segment_descriptor_table
+{
+  /**
+   * @brief Creates the global descriptor table, with the minimum required configuration. If this method is called more
+   * than once, the previously created instance is returned instead.
+   *
+   * @return Reference to the created global_descriptor_table.
+   */
+  auto get_or_create_gdt() -> global_descriptor_table &;
+
+  /**
+   * @brief Updates the GDTR with the created global descriptor table. If it has not been created yet this
+   * method will create it.
+   *
+   * @note This method will only set the GDTR, but for the processor to actually register the change a far jump
+   * has to be executed. This also has to be done before updating the TR.
+   */
+  auto update_gdtr() -> void;
+
+  /**
+   * @brief Updates the TR with the created task state segment. If it has not been created yet this
+   * method will create it.
+   *
+   * @note This method should only be called after update_gdtr() and a far jump has been
+   * executed. Because before that trying to access the segment will cause an exception.
+   */
+  auto update_tss_register() -> void;
+
+}  // namespace teachos::arch::context_switching::segment_descriptor_table
+
+#endif  // TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_GLOBAL_DESCRIPTOR_TABLE_HPP
diff --git a/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/global_descriptor_table_pointer.hpp b/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/global_descriptor_table_pointer.hpp
new file mode 100644
index 0000000..292ff70
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/global_descriptor_table_pointer.hpp
@@ -0,0 +1,41 @@
+#ifndef TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_GLOBAL_DESCRIPTOR_TABLE_POINTER_HPP
+#define TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_GLOBAL_DESCRIPTOR_TABLE_POINTER_HPP
+
+#include "arch/stl/vector.hpp"
+
+#include <cstdint>
+
+namespace teachos::arch::context_switching::segment_descriptor_table
+{
+  using global_descriptor_table = stl::vector<uint64_t>;
+
+  /**
+   * @brief Represents a pointer to the Global Descriptor Table (GDT).
+   *
+   * This structure is used to store the base address and length of the GDT.
+   * It is used when loading or modifying the GDT during context switching.
+   */
+  struct [[gnu::packed]] global_descriptor_table_pointer
+  {
+    /**
+     * @brief Default constructor.
+     */
+    global_descriptor_table_pointer() = default;
+
+    /**
+     * @brief Constructor.
+     */
+    global_descriptor_table_pointer(uint16_t table_length, uint64_t * address);
+
+    /**
+     * @brief Defaulted three-way comparsion operator.
+     */
+    auto operator<=>(global_descriptor_table_pointer const & other) const -> std::strong_ordering = default;
+
+  private:
+    uint16_t table_length = {};  ///< The amount of segment descriptor entries in the global descriptor table - 1.
+    uint64_t * address = {};     ///< Non-owning pointer to the GDT base address.
+  };
+}  // namespace teachos::arch::context_switching::segment_descriptor_table
+
+#endif  // TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_GLOBAL_DESCRIPTOR_TABLE_POINTER_HPP
diff --git a/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/segment_descriptor_base.hpp b/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/segment_descriptor_base.hpp
new file mode 100644
index 0000000..933fb4d
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/segment_descriptor_base.hpp
@@ -0,0 +1,73 @@
+#ifndef TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_SEGMENT_DESCRIPTOR_BASE_HPP
+#define TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_SEGMENT_DESCRIPTOR_BASE_HPP
+
+#include "arch/context_switching/segment_descriptor_table/access_byte.hpp"
+#include "arch/context_switching/segment_descriptor_table/gdt_flags.hpp"
+#include "arch/context_switching/segment_descriptor_table/segment_descriptor_type.hpp"
+
+namespace teachos::arch::context_switching::segment_descriptor_table
+{
+  /**
+   * @brief Defines helper function for all states and the actual data the segment descriptor can have.
+   */
+  struct [[gnu::packed]] segment_descriptor_base
+  {
+    /**
+     * @brief Default Constructor.
+     */
+    segment_descriptor_base() = default;
+
+    /**
+     * @brief Constructor.
+     *
+     * @note Created segment descriptor copies the given bytes into these components requiring the space of one
+     * segment descriptor entry in the global descriptor table being 64-bit.
+     * - 8 bit Access Type
+     * - 4 bit Flags
+     * - 32 bit Base Address
+     * - 20 bit Limit
+     *
+     * @param flags Copies the bits set from the given data into the individual components of a segment
+     * descriptor.
+     */
+    explicit segment_descriptor_base(uint64_t flags);
+
+    /**
+     * @brief Constructor.
+     *
+     * @param access_byte, flags, base, limit Copies the bits set from the given data into the individual components of
+     * a segment descriptor.
+     */
+    segment_descriptor_base(access_byte access_byte, gdt_flags flags, uint32_t base, std::bitset<20U> limit);
+
+    /**
+     * @brief Calculates the underlying segment type that this segement descriptor is describing.
+     */
+    auto get_segment_type() const -> segment_descriptor_type;
+
+    /**
+     * @brief Cast the underlying data into a combined 64-bit form, that contains all data.
+     *
+     * @return Underlying value combined into it's full size.
+     */
+    operator uint64_t() const;
+
+    /**
+     * @brief Allows to compare the underlying bits of two instances.
+     *
+     * @param other Other instance that we want to compare with.
+     * @return Whether the underlying set bits of both types are the same.
+     */
+    auto operator==(segment_descriptor_base const & other) const -> bool = default;
+
+  private:
+    // The order in private variables starts for the first variable being the rightmost bit.
+    uint16_t _limit_1 = {};      ///< First part of the limit field (0 - 15)
+    uint32_t _base_1 : 24 = {};  ///< First part of the base field (16 - 39)
+    access_byte _access = {};    ///< Access byte field (40 - 47)
+    gdt_flags _flag = {};        ///< Second part of the limit field + Flags field (48 - 55)
+    uint8_t _base_2 = {};        ///< Second part of the base field (56 - 63)
+  };
+}  // namespace teachos::arch::context_switching::segment_descriptor_table
+
+#endif  // TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_SEGMENT_DESCRIPTOR_BASE_HPP
diff --git a/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/segment_descriptor_extension.hpp b/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/segment_descriptor_extension.hpp
new file mode 100644
index 0000000..40bcc8a
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/segment_descriptor_extension.hpp
@@ -0,0 +1,74 @@
+#ifndef TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_SEGMENT_DESCRIPTOR_EXTENSION_HPP
+#define TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_SEGMENT_DESCRIPTOR_EXTENSION_HPP
+
+#include "arch/context_switching/segment_descriptor_table/segment_descriptor_base.hpp"
+
+namespace teachos::arch::context_switching::segment_descriptor_table
+{
+  __extension__ typedef __int128 int128_t;
+  __extension__ typedef unsigned __int128 uint128_t;
+
+  /**
+   * @brief Defines helper function for all states and the actual data the segment descriptor can have.
+   */
+  struct [[gnu::packed]] segment_descriptor_extension
+  {
+    /**
+     * @brief Default Constructor.
+     */
+    segment_descriptor_extension() = default;
+
+    /**
+     * @brief Constructor.
+     *
+     * @note Created segment descriptor copies the given bytes into these components requiring the space of two
+     * segment descriptor entry in the global descriptor table being 128-bit. Ending with a 32 bit reserved
+     * field that has to be used, because the segment descriptor needs to be big enough for two segment
+     * descriptor entries.
+     * - 8 bit Access Type
+     * - 4 bit Flags
+     * - 64 bit Base Address
+     * - 20 bit Limit
+     *
+     * @param flags Copies the bits set from the given data into the individual components of a segment
+     * descriptor.
+     */
+    explicit segment_descriptor_extension(uint128_t flags);
+
+    /**
+     * @brief Constructor.
+     *
+     * @param access_byte, flags, base, limit Copies the bits set from the given data into the individual components of
+     * a segment descriptor.
+     */
+    segment_descriptor_extension(access_byte access_byte, gdt_flags flags, uint64_t base, std::bitset<20U> limit);
+
+    /**
+     * @brief Returns the underlying base segment descriptor, being the first part of the segment descriptor consisting
+     * of two entries in the global descriptor table.
+     */
+    auto get_first_gdt_entry() const -> segment_descriptor_base;
+
+    /**
+     * @brief Returns the underlying extension to the segment descriptor, being the second part of the segment
+     * descriptor consiting of two entries in the global descriptor table.
+     */
+    auto get_second_gdt_entry() const -> uint64_t;
+
+    /**
+     * @brief Allows to compare the underlying bits of two instances.
+     *
+     * @param other Other instance that we want to compare with.
+     * @return Whether the underlying set bits of both types are the same.
+     */
+    auto operator==(segment_descriptor_extension const & other) const -> bool = default;
+
+  private:
+    // The order in private variables starts for the first variable being the rightmost bit.
+    segment_descriptor_base _base = {};  ///< Base Segment Descriptor representing single entry in GDT (0 - 63)
+    uint32_t _base_3 = {};               ///< Third part of the base field (63 - 95)
+    uint32_t : 32;                       ///< Reserved field used to ensure this struct is 128 bits big (96 - 127)
+  };
+}  // namespace teachos::arch::context_switching::segment_descriptor_table
+
+#endif  // TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_SEGMENT_DESCRIPTOR_EXTENSION_HPP
diff --git a/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/segment_descriptor_type.hpp b/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/segment_descriptor_type.hpp
new file mode 100644
index 0000000..8770b81
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/segment_descriptor_type.hpp
@@ -0,0 +1,27 @@
+#ifndef TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_SEGMENT_DESCRIPTOR_TYPES_HPP
+#define TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_SEGMENT_DESCRIPTOR_TYPES_HPP
+
+#include <cstdint>
+
+namespace teachos::arch::context_switching::segment_descriptor_table
+{
+  /**
+   * @brief Possible overlying types of the segment descriptor. Allowing to discern between the major types, which
+   * result in different handling of the actual data contained in the descriptor.
+   */
+  enum class segment_descriptor_type : uint8_t
+  {
+    SYSTEM_SEGMENT,  ///< The segment is of type system, is distinguished by the Descriptor Type field in the Access
+                     ///< Byte. Can be further distinguised to specific system segment types using the Type Field in the
+                     ///< Access Byte.
+    DATA_SEGMENT,    ///< The segment is of type data, is is distinguished by the Descriptor Type field in the Access
+                     ///< Byte and the first bit of the Type Field in the Access Byte. Can be further distinguised to
+                     ///< specific data segment types using the the remaining bits in the Type Field in the Access Byte.
+    CODE_SEGMENT,    ///< The segment is of type code, is is distinguished by the Descriptor Type field in
+                     ///< the Access Byte and the first bit of the Type Field in the Access Byte. Can be
+                     ///< further distinguised to specific data segment types using the the remaining bits in
+                     ///< the Type Field in the Access Byte.
+  };
+}  // namespace teachos::arch::context_switching::segment_descriptor_table
+
+#endif  // TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_SEGMENT_DESCRIPTOR_TYPES_HPP
diff --git a/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/task_state_segment.hpp b/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/task_state_segment.hpp
new file mode 100644
index 0000000..d4aa5e8
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/context_switching/segment_descriptor_table/task_state_segment.hpp
@@ -0,0 +1,32 @@
+#ifndef TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_TASK_STATE_SEGMENT_HPP
+#define TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_TASK_STATE_SEGMENT_HPP
+
+#include <cstdint>
+
+namespace teachos::arch::context_switching::segment_descriptor_table
+{
+  /**
+   * @brief 64-bit task state segment
+   */
+  struct [[gnu::packed]] task_state_segment
+  {
+  private:
+    uint32_t : 32;
+    uint64_t rsp0 = {};
+    uint64_t rsp1 = {};
+    uint64_t rsp2 = {};
+    uint64_t : 64;
+    uint64_t ist1 = {};
+    uint64_t ist2 = {};
+    uint64_t ist3 = {};
+    uint64_t ist4 = {};
+    uint64_t ist5 = {};
+    uint64_t ist6 = {};
+    uint64_t ist7 = {};
+    uint64_t : 64;
+    uint16_t : 16;
+    uint16_t io_map_base_address = {};
+  };
+}  // namespace teachos::arch::context_switching::segment_descriptor_table
+
+#endif  // TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SEGMENT_DESCRIPTOR_TABLE_TASK_STATE_SEGMENT_HPP
diff --git a/arch/x86_64/pre/include/arch/context_switching/syscall/main.hpp b/arch/x86_64/pre/include/arch/context_switching/syscall/main.hpp
new file mode 100644
index 0000000..59adc13
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/context_switching/syscall/main.hpp
@@ -0,0 +1,88 @@
+#ifndef TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SYSCALL_MAIN_HPP
+#define TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SYSCALL_MAIN_HPP
+
+#include <cstdint>
+
+namespace teachos::arch::context_switching::syscall
+{
+  /**
+   * @brief Possible syscall implementation that should actually be called.
+   *
+   * @note Attempts to reflect the Linux interface partially. See https://filippo.io/linux-syscall-table/ for more
+   * information.
+   */
+  enum class type : uint64_t
+  {
+    WRITE = 1U,  ///< Loads the arg_0 parameter as an address pointing to a const char array, which will then be printed
+                 ///< onto the VGA buffer screen.
+    EXPAND_HEAP = 2U,  /// Expands the User Heap by additonally mapping 100 KiB of virtual page memory. Ignores the
+                       /// parameters and uses them as out parameters instead, where arg_0 is the start of the newly
+                       /// mapped heap area and arg_1 is the size of the entire area. Can be less than 100 KiB if less
+                       /// space remains.
+    ASSERT = 3U,       /// Loads the arg_0 parameter as a boolean which needs to be true or it will print the message in
+                  /// arg_1 parameter onto the VGA buffer screen, keep it as a nullptr if it shouldn't print anything
+                  /// and then it halts the further execution of the application.
+  };
+
+  /**
+   * @brief Possible error codes that can be returned by the different syscall methods called depending on the type
+   * enum.
+   */
+  enum class error : uint8_t
+  {
+    OK = 0U,             ///< No error occured in syscall.
+    OUT_OF_MEMORY = 1U,  ///< Expanding heap failed because we have run out of mappable virtual address space.
+  };
+
+  /**
+   * @brief Allows to convert the error enum type into a boolean directly. Where any code besides 0 being no error, will
+   * return true. The remaining errors return true.
+   *
+   * @param e Error code that was returned by the syscall.
+   * @return Return true if there was no error and false otherwise.
+   */
+  constexpr bool operator!(error e) { return e == error::OK; }
+
+  /**
+   * @brief Maximum amount of arguments that can be passed to a syscall. Default value is 0 and arguments are only ever
+   * used depending on the actual enum type and if the method requires thoose parameters.
+   */
+  struct arguments
+  {
+    uint64_t arg_0{};  ///< First optional paramter to the syscall representing the RDI register.
+    uint64_t arg_1{};  ///< Second optional paramter to the syscall representing the RSI register.
+    uint64_t arg_2{};  ///< Third optional paramter to the syscall representing the RDX register.
+    uint64_t arg_3{};  ///< Fourth optional paramter to the syscall representing the R10 register.
+    uint64_t arg_4{};  ///< Fifth optional paramter to the syscall representing the R8 register.
+    uint64_t arg_5{};  ///< Sixth optional paramter to the syscall representing the R9 register.
+  };
+
+  /**
+   * @brief Response of a systemcall always containin an error code, signaling if the syscall even succeeded or not.
+   * Additionally it may contain up to 6 return values in the values struct.
+   */
+  struct response
+  {
+    error error_code;       ///< Error code returned by the syscall. If it failed all the values will be 0.
+    arguments values = {};  ///< Optional return values of the syscall implementation.
+  };
+
+  /**
+   * @brief Calls the method associated with the given syscall number and passes the given optional arguments to it,
+   * over the RDI, RSI, RDX, R10, R8 and R9 register.
+   *
+   * @param syscall_number Syscall method that should be called. See enum values in type for possible implemented
+   * methods.
+   * @param args Optional arguments passable to the different syscall methods, called depending on the syscall_number.
+   * Not passing the required parameters to the method, will result in passing 0 instead, which might make the fail or
+   * not function correctly.
+   * @return The syscall implementation always returns a bool-convertable error code converting to true if the syscall
+   * failed or false if it didn't. Additionally it might pase additional values besides the error code, they will be set
+   * in the arguments struct. So the value can be read and used for further processing.
+   */
+  [[gnu::section(".user_text")]]
+  auto syscall(type syscall_number, arguments args = {}) -> response;
+
+}  // namespace teachos::arch::context_switching::syscall
+
+#endif  // TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SYSCALL_MAIN_HPP
diff --git a/arch/x86_64/pre/include/arch/context_switching/syscall/syscall_enable.hpp b/arch/x86_64/pre/include/arch/context_switching/syscall/syscall_enable.hpp
new file mode 100644
index 0000000..8cb468a
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/context_switching/syscall/syscall_enable.hpp
@@ -0,0 +1,18 @@
+#ifndef TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SYSCALL_SYSCALL_ENABLE_HPP
+#define TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SYSCALL_SYSCALL_ENABLE_HPP
+
+namespace teachos::arch::context_switching::syscall
+{
+  /**
+   * @brief Enables and sets up internal CPU registers to allow for syscall to function correctly and switch context
+   * temporarily back to the kernel level.
+   *
+   * @note Configures the Model Specific Register required by syscall (LSTAR, FMASK, STAR) with the correct values so
+   * that the syscall_handler is called and sets the System Call Extension bit on the EFER flags to allow for syscall
+   * to be used.
+   */
+  auto enable_syscall() -> void;
+
+}  // namespace teachos::arch::context_switching::syscall
+
+#endif  // TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SYSCALL_SYSCALL_ENABLE_HPP
diff --git a/arch/x86_64/pre/include/arch/context_switching/syscall/syscall_handler.hpp b/arch/x86_64/pre/include/arch/context_switching/syscall/syscall_handler.hpp
new file mode 100644
index 0000000..2e7bcd1
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/context_switching/syscall/syscall_handler.hpp
@@ -0,0 +1,18 @@
+#ifndef TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SYSCALL_SYSCALL_HANDLER_HPP
+#define TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SYSCALL_SYSCALL_HANDLER_HPP
+
+#include <cstdint>
+
+namespace teachos::arch::context_switching::syscall
+{
+  /**
+   * @brief Handler for SYSCALL instruction. Calls a specific implementation based
+   * on the register RAX.
+   *
+   * @return Returns with LEAVE, SYSRETQ
+   */
+  auto syscall_handler() -> void;
+
+}  // namespace teachos::arch::context_switching::syscall
+
+#endif  // TEACHOS_ARCH_X86_64_CONTEXT_SWITCHING_SYSCALL_SYSCALL_HANDLER_HPP
diff --git a/arch/x86_64/pre/include/arch/exception_handling/assert.hpp b/arch/x86_64/pre/include/arch/exception_handling/assert.hpp
new file mode 100644
index 0000000..1286768
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/exception_handling/assert.hpp
@@ -0,0 +1,17 @@
+#ifndef TEACHOS_ARCH_X86_64_EXCEPTION_HANDLING_ASSERT_HPP
+#define TEACHOS_ARCH_X86_64_EXCEPTION_HANDLING_ASSERT_HPP
+
+namespace teachos::arch::exception_handling
+{
+  /**
+   * @brief Assert a condition to be true, if not do not continue
+   * execution of the code and print the given message to screen.
+   *
+   * @param condition Condition we want to be true or else halt execution.
+   * @param message Message that should be printed before halting the execution if the condition is not met.
+   */
+  auto assert(bool condition, char const * message) -> void;
+
+}  // namespace teachos::arch::exception_handling
+
+#endif  // TEACHOS_ARCH_X86_64_EXCEPTION_HANDLING_ASSERT_HPP
diff --git a/arch/x86_64/pre/include/arch/exception_handling/panic.hpp b/arch/x86_64/pre/include/arch/exception_handling/panic.hpp
new file mode 100644
index 0000000..6a2404c
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/exception_handling/panic.hpp
@@ -0,0 +1,23 @@
+#ifndef TEACHOS_ARCH_X86_64_EXCEPTION_HANDLING_PANIC_HPP
+#define TEACHOS_ARCH_X86_64_EXCEPTION_HANDLING_PANIC_HPP
+
+namespace teachos::arch::exception_handling
+{
+  /**
+   * @brief Print the given kernel panic message and then halt the system.
+   *
+   * @param reason Reason to print before halting the system.
+   */
+  [[noreturn]] auto panic(char const * reason) -> void;
+
+  /**
+   * @brief Print the given kernel panic message started by a given prefix and then halt the system.
+   *
+   * @param prefix Prefix to print before printing the reason.
+   * @param reason Reason to print before halting the system.
+   */
+  [[noreturn]] auto panic(char const * prefix, char const * reason) -> void;
+
+}  // namespace teachos::arch::exception_handling
+
+#endif  // TEACHOS_ARCH_X86_64_EXCEPTION_HANDLING_PANIC_HPP
diff --git a/arch/x86_64/pre/include/arch/interrupt_handling/generic_interrupt_handler.hpp b/arch/x86_64/pre/include/arch/interrupt_handling/generic_interrupt_handler.hpp
new file mode 100644
index 0000000..15b35c1
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/interrupt_handling/generic_interrupt_handler.hpp
@@ -0,0 +1,34 @@
+#ifndef TEACHOS_ARCH_X86_64_INTERRUPT_HANDLING_GENERIC_INTERRUPT_HANDLER_HPP
+#define TEACHOS_ARCH_X86_64_INTERRUPT_HANDLING_GENERIC_INTERRUPT_HANDLER_HPP
+
+#include <cstdint>
+
+namespace teachos::arch::interrupt_handling
+{
+  /**
+   * @brief Represents the CPU state during an interrupt.
+   *
+   * Some interrupts push an error code, while others do not. The full list
+   * of which vector number contains the error code can be found here: https://wiki.osdev.org/Exceptions
+   */
+  struct [[gnu::packed]] interrupt_frame
+  {
+    // uint64_t error_code;  ///< Error code only pushed by some exceptions, therefore it is commented out.
+    uint64_t ip;     ///< Instruction pointer at the time of the interrupt.
+    uint64_t cs;     ///< Code segment selector indicating privilege level.
+    uint64_t flags;  ///< CPU flags (RFLAGS) storing processor state.
+    uint64_t sp;     ///< Stack pointer at the time of the interrupt.
+    uint64_t ss;     ///< Stack segment selector, usually unused in 64-bit mode.
+  };
+
+  /**
+   * @brief Generic interrupt handler function.
+   *
+   * @param frame Pointer to the interrupt frame containing CPU state.
+   */
+  [[gnu::interrupt]]
+  auto generic_interrupt_handler(interrupt_frame * frame) -> void;
+
+}  // namespace teachos::arch::interrupt_handling
+
+#endif  // TEACHOS_ARCH_X86_64_INTERRUPT_HANDLING_GENERIC_INTERRUPT_HANDLER_HPP
diff --git a/arch/x86_64/pre/include/arch/kernel/cpu/call.hpp b/arch/x86_64/pre/include/arch/kernel/cpu/call.hpp
new file mode 100644
index 0000000..3c43304
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/kernel/cpu/call.hpp
@@ -0,0 +1,30 @@
+#ifndef TEACHOS_ARCH_X86_64_KERNEL_CPU_JMP_HPP
+#define TEACHOS_ARCH_X86_64_KERNEL_CPU_JMP_HPP
+
+#include "arch/context_switching/interrupt_descriptor_table/segment_selector.hpp"
+
+#include <cstdint>
+
+namespace teachos::arch::kernel::cpu
+{
+  /**
+   * @brief Far Pointer. Address to function located in another code segment.
+   */
+  struct far_pointer
+  {
+    void (*function)();  ///< Address of the function we want to call. (0-63)
+    context_switching::interrupt_descriptor_table::segment_selector
+        selector;  ///< Segment selector pointing to the GDT entry we want to load into register CS. (64-79)
+  };
+
+  /**
+   * @brief Far call - A call to an instruction located in a different segment than the current code segment but at the
+   * same privilege level.
+   *
+   * @param pointer 64-bit operand size far pointer that we want to call.
+   */
+  auto call(far_pointer pointer) -> void;
+
+}  // namespace teachos::arch::kernel::cpu
+
+#endif  // TEACHOS_ARCH_X86_64_KERNEL_CPU_JMP_HPP
diff --git a/arch/x86_64/pre/include/arch/kernel/cpu/gdtr.hpp b/arch/x86_64/pre/include/arch/kernel/cpu/gdtr.hpp
new file mode 100644
index 0000000..68b950d
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/kernel/cpu/gdtr.hpp
@@ -0,0 +1,27 @@
+#ifndef TEACHOS_ARCH_X86_64_KERNEL_CPU_GDTR_HPP
+#define TEACHOS_ARCH_X86_64_KERNEL_CPU_GDTR_HPP
+
+#include "arch/context_switching/segment_descriptor_table/global_descriptor_table_pointer.hpp"
+
+#include <bitset>
+#include <cstdint>
+
+namespace teachos::arch::kernel::cpu
+{
+
+  /**
+   * @brief Returns the value in the GDTR register.
+   *
+   * @return Value of GDTR register.
+   */
+  auto store_global_descriptor_table() -> context_switching::segment_descriptor_table::global_descriptor_table_pointer;
+
+  /**
+   * @brief Loads the global_descriptor_table_pointer into the global descriptor table register (GDTR).
+   */
+  auto load_global_descriptor_table(
+      context_switching::segment_descriptor_table::global_descriptor_table_pointer const & gdt_pointer) -> void;
+
+}  // namespace teachos::arch::kernel::cpu
+
+#endif  // TEACHOS_ARCH_X86_64_KERNEL_CPU_GDTR_HPP
diff --git a/arch/x86_64/pre/include/arch/kernel/cpu/idtr.hpp b/arch/x86_64/pre/include/arch/kernel/cpu/idtr.hpp
new file mode 100644
index 0000000..cb800d0
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/kernel/cpu/idtr.hpp
@@ -0,0 +1,27 @@
+#ifndef TEACHOS_ARCH_X86_64_KERNEL_CPU_IDTR_HPP
+#define TEACHOS_ARCH_X86_64_KERNEL_CPU_IDTR_HPP
+
+#include "arch/context_switching/interrupt_descriptor_table/interrupt_descriptor_table_pointer.hpp"
+
+#include <bitset>
+#include <cstdint>
+
+namespace teachos::arch::kernel::cpu
+{
+  /**
+   * @brief Returns the value in the IDTR register.
+   *
+   * @return Value of IDTR register.
+   */
+  auto store_interrupt_descriptor_table()
+      -> context_switching::interrupt_descriptor_table::interrupt_descriptor_table_pointer;
+
+  /**
+   * @brief Loads the interrupt_descriptor_table_pointer into the interrupt descriptor table register (IDTR).
+   */
+  auto load_interrupt_descriptor_table(
+      context_switching::interrupt_descriptor_table::interrupt_descriptor_table_pointer const & idt_pointer) -> void;
+
+}  // namespace teachos::arch::kernel::cpu
+
+#endif  // TEACHOS_ARCH_X86_64_KERNEL_CPU_IDTR_HPP
diff --git a/arch/x86_64/pre/include/arch/kernel/cpu/if.hpp b/arch/x86_64/pre/include/arch/kernel/cpu/if.hpp
new file mode 100644
index 0000000..48707dc
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/kernel/cpu/if.hpp
@@ -0,0 +1,21 @@
+#ifndef TEACHOS_ARCH_X86_64_KERNEL_CPU_IF_HPP
+#define TEACHOS_ARCH_X86_64_KERNEL_CPU_IF_HPP
+
+namespace teachos::arch::kernel::cpu
+{
+  /**
+   * @brief Sets the interrupt flag (IF) in the EFLAGS register.
+   * This allows the processor to respond to maskable hardware interrupts.
+   */
+  auto set_interrupt_flag() -> void;
+
+  /**
+   * @brief Clears the interrupt flag (IF) in the EFLAGS register.
+   * This will stop the processor to respond to maskable hardware interrupts and needs to be done before changing the
+   * Interrupt Descriptor Table with lidt.
+   */
+  auto clear_interrupt_flag() -> void;
+
+}  // namespace teachos::arch::kernel::cpu
+
+#endif  // TEACHOS_ARCH_X86_64_KERNEL_CPU_IF_HPP
diff --git a/arch/x86_64/pre/include/arch/kernel/cpu/msr.hpp b/arch/x86_64/pre/include/arch/kernel/cpu/msr.hpp
new file mode 100644
index 0000000..99d6378
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/kernel/cpu/msr.hpp
@@ -0,0 +1,64 @@
+#ifndef TEACHOS_ARCH_X86_64_KERNEL_CPU_NXE_HPP
+#define TEACHOS_ARCH_X86_64_KERNEL_CPU_NXE_HPP
+
+#include <bitset>
+#include <cstdint>
+
+namespace teachos::arch::kernel::cpu
+{
+  /**
+   * @brief Important flags that can be writen into the Extended Feature Enable Register (EFER).
+   *
+   * @note EFER is a model-specific register allowing to configure CPU extensions. Only the most important extensions
+   * are listed below, the rest are excluded for brevity. See https://en.wikipedia.org/wiki/Control_register#EFER for
+   * more information.
+   */
+  enum class efer_flags : uint64_t
+  {
+    SCE = 1UL << 0UL,     ///< System Call Extensions.
+    LME = 1UL << 8UL,     ///< Long Mode Enabled.
+    LMA = 1UL << 10UL,    ///< Long Mode Active.
+    NXE = 1UL << 11UL,    ///< No-Execute Enable.
+    SVME = 1UL << 12UL,   ///< Secure Virtual Machine Enable.
+    LMSLE = 1UL << 13UL,  ///< Long Mode Segment Limit Enable.
+    FFXSR = 1UL << 14UL,  ///< Fast FXSAVE/FXSTOR.
+    TCE = 1UL << 15UL,    ///< Translation Cache Extension.
+  };
+
+  /**
+   * @brief Reads a 64-bit from the Model-Specific Register (MSR).
+   *
+   * @note This function reads the value of an MSR specified by the given address. It combines the lower and upper
+   * 32-bits of the MSR value read using the 'rdmsr' instruction and returns it as a 64-bit unsigned integer.
+   *
+   * @param msr The address of the MSR to read.
+   * @return The 64-bit value read from the MSR.
+   */
+  auto read_msr(uint32_t msr) -> uint64_t;
+
+  /**
+   * @brief Writes a 64-bit value to a Model-Specific Register (MSR).
+   *
+   * @note This function writes a 64-bit value to the MSR specified by the given address.
+   * It splits the 64-bit value into two 32-bit parts and writes them using the
+   * `wrmsr` instruction.
+   *
+   * @param msr The address of the MSR to write to.
+   * @param new_value The 64-bit value to write to the MSR.
+   */
+  auto write_msr(uint32_t msr, uint64_t new_value) -> void;
+
+  /**
+   * @brief Sets a specific bit in the Extended Feature Enable Register (EFER), which is a Model-Specific Register
+   * (MSR).
+   *
+   * @note This function reads the current value of the EFER register, ORs the specified
+   * bit with the current value, and writes the updated value back to the EFER register.
+   *
+   * @param flag The flag to set in the EFER register.
+   */
+  auto set_efer_bit(efer_flags flag) -> void;
+
+}  // namespace teachos::arch::kernel::cpu
+
+#endif  // TEACHOS_ARCH_X86_64_KERNEL_CPU_NXE_HPP
\ No newline at end of file
diff --git a/arch/x86_64/pre/include/arch/kernel/cpu/segment_register.hpp b/arch/x86_64/pre/include/arch/kernel/cpu/segment_register.hpp
new file mode 100644
index 0000000..a236452
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/kernel/cpu/segment_register.hpp
@@ -0,0 +1,97 @@
+#ifndef TEACHOS_ARCH_X86_64_KERNEL_CPU_SEGMENT_REGISTER_HPP
+#define TEACHOS_ARCH_X86_64_KERNEL_CPU_SEGMENT_REGISTER_HPP
+
+#include "arch/context_switching/interrupt_descriptor_table/segment_selector.hpp"
+
+namespace teachos::arch::kernel::cpu
+{
+  /**
+   * @brief Clear all Data Segment registers (DS / ES / FS / GS).
+   */
+  auto reload_data_segment_registers() -> void;
+
+  /**
+   * @brief Updates the value of the Data Segment Register (DS), Extra Segment Register (ES), Thread-Local Storage
+   * Registers (FS / GS).
+   *
+   * @note The Stack Segment Register (SS) value should also be updated, but the value can not be directly set in
+   * comparsion to the other registers. This is the case because the register is used for stack management and can not
+   * be directly changed, instead this has to be done by a special instruction. Therefore
+   * validate_data_segment_registers should only be called after set_code_segment_register has been called as well.
+   *
+   * @param data_segment Value that should be loaded into the registers.
+   */
+  auto set_data_segment_registers(context_switching::interrupt_descriptor_table::segment_selector data_segment) -> void;
+
+  /**
+   * @brief Returns the Segment Selector pointing to the Code Segment that has been loaded into the Code Segment
+   * Register (CS).
+   *
+   * @note The CS register can not be directly changed, instead a Far Return has to be executed to change it
+   *
+   * @return Segment Selector pointing to the currently loaded Code Segment.
+   */
+  [[gnu::section(".user_text")]]
+  auto read_code_segment_register() -> context_switching::interrupt_descriptor_table::segment_selector;
+
+  /**
+   * @brief Validates that all Data Segment Registers (DS / ES / FS / GS / SS) are the same as the given Data Segment
+   * and asserts and stops the application if they are not.
+   *
+   * @note This is only the case after set_code_segment_register has been executed as well, because it makes a far
+   * return that updates the SS register.
+   *
+   * @param data_segment Value that should be loaded into all Data Segment Registers.
+   */
+  auto validate_data_segment_registers(context_switching::interrupt_descriptor_table::segment_selector data_segment)
+      -> void;
+
+  /**
+   * @brief Validates that the Code Segment Register (CS) is the same as the given Code Segment
+   * and asserts and stops the application if they are not.
+   *
+   * @param code_segment Value that should be loaded into the Code Segment Register.
+   */
+  auto validate_code_segment_register(context_switching::interrupt_descriptor_table::segment_selector code_segment)
+      -> void;
+
+  /**
+   * @brief Simply forwards the call to validate_data_segment_registers and validate_code_segment_register and ensures
+   * that all Segment Registers, have been configured correctly.
+   *
+   * @note If all Segment Register have been set correctly the Context Switch using the set_code_segment_register method
+   * was successfull and the Privilege Level has been changed.
+   *
+   * @param data_segment Value that should be loaded into all Data Segment Registers.
+   * @param code_segment Value that should be loaded into the Code Segment Register.
+   */
+  auto validate_segment_registers(context_switching::interrupt_descriptor_table::segment_selector data_segment,
+                                  context_switching::interrupt_descriptor_table::segment_selector code_segment) -> void;
+
+  /**
+   * @brief Sets the value of the Code Segment Register (CS), this is achieved using a Far Return.
+   *
+   * @note The Far Return used by this method, will cause the context to switch, because we are changing from the
+   * current Code Segment and it's associated  Privilege Level to another Code Segment. The given method will then be
+   * called in the new context and it should be possible to call validate_segment_registers, with the same values
+   * without assertions if the switch was successful.
+   *
+   * To achieve this Far Return we call IRETQ, which expects the stack to be defined a certain way to achieve that we:
+   * 1. Push the Data Segment Selector
+   * 2. Push the current Stack Pointer
+   * 3. Push Eflags
+   * 4. Push Code Segment Selector
+   * 5. Push Return Address
+   *
+   * @param data_segment Data Segment that should be loaded into the SS register.
+   * @param code_segment Code Segment that should be loaded into the CS register.
+   * @param address Function that we want to call in the new context created by the given Code Segment.
+   */
+  [[gnu::naked]]
+  auto set_code_segment_register(context_switching::interrupt_descriptor_table::segment_selector data_segment,
+                                 context_switching::interrupt_descriptor_table::segment_selector code_segment,
+                                 uint64_t address) -> void;
+
+}  // namespace teachos::arch::kernel::cpu
+
+#endif  // TEACHOS_ARCH_X86_64_KERNEL_CPU_SEGMENT_REGISTER_HPP
diff --git a/arch/x86_64/pre/include/arch/kernel/cpu/tr.hpp b/arch/x86_64/pre/include/arch/kernel/cpu/tr.hpp
new file mode 100644
index 0000000..7c856f1
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/kernel/cpu/tr.hpp
@@ -0,0 +1,24 @@
+#ifndef TEACHOS_ARCH_X86_64_KERNEL_CPU_TR_HPP
+#define TEACHOS_ARCH_X86_64_KERNEL_CPU_TR_HPP
+
+#include <bitset>
+#include <cstdint>
+
+namespace teachos::arch::kernel::cpu
+{
+
+  /**
+   * @brief Returns the value in the LTR register.
+   *
+   * @return Value of LTR register.
+   */
+  auto store_task_register() -> uint16_t;
+
+  /**
+   * @brief Loads the gdt offset to the tss segment descriptor into the task register (TR).
+   */
+  auto load_task_register(uint16_t gdt_offset) -> void;
+
+}  // namespace teachos::arch::kernel::cpu
+
+#endif  // TEACHOS_ARCH_X86_64_KERNEL_CPU_TR_HPP
diff --git a/arch/x86_64/pre/include/arch/kernel/halt.hpp b/arch/x86_64/pre/include/arch/kernel/halt.hpp
new file mode 100644
index 0000000..377acc0
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/kernel/halt.hpp
@@ -0,0 +1,13 @@
+#ifndef TEACHOS_ARCH_X86_64_KERNEL_HALT_HPP
+#define TEACHOS_ARCH_X86_64_KERNEL_HALT_HPP
+
+namespace teachos::arch::kernel
+{
+  /**
+   * @brief Halts the kernel execution, meaning any code after a call to this will not run anymore.
+   */
+  extern "C" [[noreturn]] auto halt() -> void;
+
+}  // namespace teachos::arch::kernel
+
+#endif  // TEACHOS_ARCH_X86_64_KERNEL_HALT_HPP
diff --git a/arch/x86_64/pre/include/arch/kernel/main.hpp b/arch/x86_64/pre/include/arch/kernel/main.hpp
new file mode 100644
index 0000000..a13e5f4
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/kernel/main.hpp
@@ -0,0 +1,13 @@
+#ifndef TEACHOS_ARCH_X86_64_KERNEL_MAIN_HPP
+#define TEACHOS_ARCH_X86_64_KERNEL_MAIN_HPP
+
+namespace teachos::arch::kernel
+{
+  /**
+   * @brief Initalizes the kernel system.
+   */
+  auto main() -> void;
+
+}  // namespace teachos::arch::kernel
+
+#endif  // TEACHOS_ARCH_X86_64_KERNEL_MAIN_HPP
diff --git a/arch/x86_64/pre/include/arch/memory/allocator/area_frame_allocator.hpp b/arch/x86_64/pre/include/arch/memory/allocator/area_frame_allocator.hpp
new file mode 100644
index 0000000..a86c9b7
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/allocator/area_frame_allocator.hpp
@@ -0,0 +1,67 @@
+#ifndef TEACHOS_X86_64_MEMORY_AREA_ALLOCATOR_HPP
+#define TEACHOS_X86_64_MEMORY_AREA_ALLOCATOR_HPP
+
+// #include "arch/memory/allocator/physical_frame.hpp"
+// #include "arch/memory/multiboot/reader.hpp"
+
+#include <optional>
+
+namespace x86_64::memory
+{
+  /**
+   * @brief Allocates memory linearly using memory areas read from the multiboot2 information pointer and leaks any
+   * deallocated frames.
+   */
+  struct area_frame_allocator
+  {
+    /**
+     * @brief Constructor.
+     *
+     * @param mem_info Structure containg all relevant information to map and allocate memory.
+     */
+    area_frame_allocator(multiboot::memory_information const & mem_info);
+
+    /**
+     * @brief Allocate memory by finding and returning a free physical frame.
+     *
+     * @note The physical_frame allocation executes multiple checks before returning
+     * the physical_frame that is available to allocate. It must at least
+     * do the following:
+     * - check if the next_free_frame is within the current_area
+     * - check if the next_free_frame is actually free
+     * - update the next_free_frame after finding a free physical_frame
+     *
+     * @return next free physical frame or nullopt if none was found.
+     */
+    auto allocate_frame() -> std::optional<physical_frame>;
+
+    /**
+     * @brief Deallocates a previously allocated physical frame.
+     *
+     * @note Simply does nothing, because the simply area frame
+     * allocator implementation does not keep track of free or used frames and can therefore not deallocate, because it
+     * does not know which frames have been alocated in the first place.
+     *
+     * @param physical_frame Previously allocated physical_frame that should be deallocated.
+     */
+    auto deallocate_frame(physical_frame const & physical_frame) -> void;
+
+  private:
+    /**
+     * @brief Find the next memory area and write it into current_area.
+     */
+    auto choose_next_area() -> void;
+
+    physical_frame next_free_frame;                      ///< The physical_frame after the last allocated one.
+    std::optional<multiboot::memory_area> current_area;  ///< The current memory area.
+    multiboot::memory_area_container const
+        memory_areas;                      ///< All memory areas in custom container allows to use std::ranges.
+    physical_frame const kernel_start;     ///< The start address of the kernel code in memory.
+    physical_frame const kernel_end;       ///< The end address of the kernel code in memory.
+    physical_frame const multiboot_start;  ///< The start address of the multiboot code in memory.
+    physical_frame const multiboot_end;    ///< The end address of the multiboot code in memory.
+  };
+
+}  // namespace x86_64::memory
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_ALLOCATOR_AREA_FRAME_ALLOCATOR_HPP
diff --git a/arch/x86_64/pre/include/arch/memory/allocator/concept.hpp b/arch/x86_64/pre/include/arch/memory/allocator/concept.hpp
new file mode 100644
index 0000000..2d3f4ae
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/allocator/concept.hpp
@@ -0,0 +1,21 @@
+#ifndef TEACHOS_ARCH_X86_64_MEMORY_ALLOCATOR_CONCEPT_HPP
+#define TEACHOS_ARCH_X86_64_MEMORY_ALLOCATOR_CONCEPT_HPP
+
+#include "arch/memory/allocator/physical_frame.hpp"
+
+#include <optional>
+
+namespace teachos::arch::memory::allocator
+{
+  /**
+   * @brief Frame allocator concept required for allocating and deallocating physical frames in memory.
+   */
+  template<typename T>
+  concept FrameAllocator = requires(T t, physical_frame const & a) {
+    { t.allocate_frame() } -> std::same_as<std::optional<physical_frame>>;
+    { t.deallocate_frame(a) } -> std::same_as<void>;
+  };
+
+}  // namespace teachos::arch::memory::allocator
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_ALLOCATOR_CONCEPT_HPP
diff --git a/arch/x86_64/pre/include/arch/memory/allocator/tiny_frame_allocator.hpp b/arch/x86_64/pre/include/arch/memory/allocator/tiny_frame_allocator.hpp
new file mode 100644
index 0000000..1ceb74d
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/allocator/tiny_frame_allocator.hpp
@@ -0,0 +1,74 @@
+#ifndef TEACHOS_ARCH_X86_64_MEMORY_ALLOCATOR_TINY_FRAME_ALLOCATOR_HPP
+#define TEACHOS_ARCH_X86_64_MEMORY_ALLOCATOR_TINY_FRAME_ALLOCATOR_HPP
+
+#include "arch/memory/allocator/concept.hpp"
+#include "arch/memory/allocator/physical_frame.hpp"
+
+#include <array>
+
+namespace teachos::arch::memory::allocator
+{
+  namespace
+  {
+    uint8_t constexpr TINY_ALLOCATOR_FRAMES_COUNT = 3U;
+  }
+
+  /**
+   * @brief Allocates memory using memory areas read from the multiboot2 information pointer. Does not allocate its own
+   * frames, but uses the necessary three frames provided by another allocator to map one virtual level 1 page entry and
+   * the necessary upper layers.
+   */
+  struct tiny_frame_allocator
+  {
+    /**
+     * @brief Constructor.
+     *
+     * @tparam T Contract the allocator that should be used to actually allocate and deallocate, the underlying three
+     * frames has to follow.
+     *
+     * @param allocator Reference to an allocator following the FrameAllocator concept, which is used to allocate
+     * entries when the underlying frames are created.
+     */
+    template<allocator::FrameAllocator T>
+    tiny_frame_allocator(T & allocator)
+        : frames{}
+    {
+      // Has to be done this way, because constructing the constructor with the data from allocator.allocate_frames(),
+      // does not work because it would set the value correctly but because we pass it as an std::optional it would not
+      // set the engaged flag. Meaning the has_value() method would still return false.
+      for (auto & frame : frames)
+      {
+        auto allocated = allocator.allocate_frame();
+        if (allocated.has_value())
+        {
+          frame.emplace(allocated.value());
+        }
+      }
+    }
+
+    /**
+     * @brief Allocate memory by finding and returning one of the three free physical frames.
+     *
+     * @return First free physical frames of the three frames held by this allocator or nullopt if we used up all three
+     * frames already.
+     */
+    auto allocate_frame() -> std::optional<physical_frame>;
+
+    /**
+     * @brief Deallocates one of the three previously allocated physical frames.
+     *
+     * @note If more than the three frames are deallocated the method will halt execution, because it can only hold 3
+     * frames.
+     *
+     * @param physical_frame Previously allocated physical_frame that should be deallocated.
+     */
+    auto deallocate_frame(physical_frame const & physical_frame) -> void;
+
+  private:
+    std::array<std::optional<physical_frame>, TINY_ALLOCATOR_FRAMES_COUNT> frames =
+        {};  ///< Container that holds the frames allocated by another allocator.
+  };
+
+}  // namespace teachos::arch::memory::allocator
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_ALLOCATOR_TINY_FRAME_ALLOCATOR_HPP
diff --git a/arch/x86_64/pre/include/arch/memory/heap/bump_allocator.hpp b/arch/x86_64/pre/include/arch/memory/heap/bump_allocator.hpp
new file mode 100644
index 0000000..011f45c
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/heap/bump_allocator.hpp
@@ -0,0 +1,48 @@
+#ifndef TEACHOS_ARCH_X86_64_MEMORY_HEAP_BUMP_ALLOCATOR_HPP
+#define TEACHOS_ARCH_X86_64_MEMORY_HEAP_BUMP_ALLOCATOR_HPP
+
+#include "arch/memory/heap/heap_allocator.hpp"
+
+#include <atomic>
+#include <cstdint>
+
+namespace teachos::arch::memory::heap
+{
+  /**
+   * @brief Simple heap allocator, which allocates linearly and leaks all allocated memory, because it does not really
+   * deallocate anything.
+   */
+  struct bump_allocator : heap_allocator
+  {
+    /**
+     * @brief Constructor.
+     *
+     * @param heap_start Start of the allocatable heap area
+     * @param heap_end End of the allocatable heap area (Start + Size)
+     */
+    bump_allocator(std::size_t heap_start, std::size_t heap_end)
+        : heap_start{heap_start}
+        , heap_end{heap_end}
+        , next{heap_start}
+    {
+      // Nothing to do
+    }
+
+    auto allocate(std::size_t size) -> void * override;
+
+    /**
+     * @copybrief heap_allocator::deallocate
+     *
+     * @note Simply does nothing, because this allocator leaks all memory
+     */
+    auto deallocate(void * pointer) noexcept -> void override;
+
+  private:
+    std::size_t heap_start;     ///< Start of the allocatable heap area
+    std::size_t heap_end;       ///< End of the allocatable heap area
+    std::atomic_uint64_t next;  ///< Current address, which is the start of still unused allocatable heap area
+  };
+
+}  // namespace teachos::arch::memory::heap
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_HEAP_BUMP_ALLOCATOR_HPP
diff --git a/arch/x86_64/pre/include/arch/memory/heap/global_heap_allocator.hpp b/arch/x86_64/pre/include/arch/memory/heap/global_heap_allocator.hpp
new file mode 100644
index 0000000..c98c130
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/heap/global_heap_allocator.hpp
@@ -0,0 +1,118 @@
+#ifndef TEACHOS_ARCH_X86_64_MEMORY_HEAP_GLOBAL_HEAP_ALLOCATOR_HPP
+#define TEACHOS_ARCH_X86_64_MEMORY_HEAP_GLOBAL_HEAP_ALLOCATOR_HPP
+
+#include "arch/memory/heap/heap_allocator.hpp"
+#include "arch/memory/heap/user_heap_allocator.hpp"
+
+namespace teachos::arch::memory::heap
+{
+  /**
+   * @brief Possible types that should be constructed by the register_heap_allocator factory method.
+   * Creates the underlying heap allocator instance that is then used by all global allocations using new and delete
+   */
+  enum class heap_allocator_type : uint8_t
+  {
+    NONE,  ///< Don't use any heap allocation implementation, this will result in all calls of new and delte halting
+           ///< further execution of the kernel
+    BUMP,  ///< Use the bump allocator as the heap allocation implementation, be aware that using this allocator leaks
+           ///< memory, because there is no delete implementation
+    LINKED_LIST  ///< Use the linked list allocator as the heap implementation, recommended because it does not leak
+                 ///< memory
+  };
+
+  /**
+   * @brief Global instance of a heap allocator implementation created by the factory method pattern @see
+   * https://refactoring.guru/design-patterns/factory-method for more information.
+   *
+   * @note Can only be registered once and only once the kernel and the heap part of the kernel has been remapped
+   * successfully. If the instance is created before than the device will abort, because it acceses unmapped memory
+   * areas.
+   */
+  struct global_heap_allocator
+  {
+    /**
+     * @brief Registers the heap allocation implementation that should be used by the global heap allocator.
+     * Meaning all future calls to the global new or delete will be forwarded to the allocate and deallocate calls of
+     * the underlying heap allocation implementation
+     *
+     * @param new_type Type of the heap allocation implementation we want to instantiate
+     */
+    static auto register_heap_allocator(heap_allocator_type new_type) -> void;
+
+    /**
+     * @brief Allocates the given amount of memory and returns the pointer to the start of the allocatable memory area.
+     * Simply forwards the call to the allocate method of the registered heap_allocation implementation
+     *
+     * @param size Amount of bytes that should be allocated
+     * @return void* Pointer to the start of the allocatable memory area
+     */
+    static auto kmalloc(std::size_t size) -> void *;
+
+    /**
+     * @brief Deallocated all memory associated with the memory area starting from the given pointer address.
+     * Simply forwards the call to the deallocate method of the registered heap_allocation implementation
+     *
+     * @param pointer Previously allocated memory area, that should now be freed
+     */
+    static auto kfree(void * pointer) noexcept -> void;
+
+    /**
+     * @brief Allocates the given amount of memory and returns the pointer to the start of the allocatable memory area.
+     * Simply forwards the call to the allocate method of the registered heap_allocation implementation
+     *
+     * @param size Amount of bytes that should be allocated
+     * @return void* Pointer to the start of the allocatable memory area
+     */
+    [[gnu::section(".user_text")]]
+    static auto malloc(std::size_t size) -> void *;
+
+    /**
+     * @brief Deallocated all memory associated with the memory area starting from the given pointer address.
+     * Simply forwards the call to the deallocate method of the registered heap_allocation implementation
+     *
+     * @param pointer Previously allocated memory area, that should now be freed
+     */
+    [[gnu::section(".user_text")]]
+    static auto free(void * pointer) noexcept -> void;
+
+  private:
+    static heap_allocator * kernel_allocator_instance;  ///< Instance used to allocate and deallocate kernel heap memory
+    [[gnu::section(".user_data")]] static user_heap_allocator *
+        user_allocator_instance;  ///< Instance used to allocate and deallocate user heap memory
+
+    /**
+     * @brief Either returns the previously registered heap allocated or halts further execution
+     *
+     * @return Reference to the registered kernel heap allocation
+     */
+    static auto kernel() -> heap_allocator &;
+
+    /**
+     * @brief Either returns the previously registered heap allocated or halts further execution
+     *
+     * @return Reference to the registered user heap allocation
+     */
+    [[gnu::section(".user_text")]]
+    static auto user() -> user_heap_allocator &;
+  };
+}  // namespace teachos::arch::memory::heap
+
+[[gnu::section(".user_text")]]
+auto operator new(std::size_t size) -> void *;
+
+[[gnu::section(".user_text")]]
+auto operator delete(void * pointer) noexcept -> void;
+
+[[gnu::section(".user_text")]]
+auto operator delete(void * pointer, std::size_t size) noexcept -> void;
+
+[[gnu::section(".user_text")]]
+auto operator new[](std::size_t size) -> void *;
+
+[[gnu::section(".user_text")]]
+auto operator delete[](void * pointer) noexcept -> void;
+
+[[gnu::section(".user_text")]]
+auto operator delete[](void * pointer, std::size_t size) noexcept -> void;
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_HEAP_GLOBAL_HEAP_ALLOCATOR_HPP
diff --git a/arch/x86_64/pre/include/arch/memory/heap/heap_allocator.hpp b/arch/x86_64/pre/include/arch/memory/heap/heap_allocator.hpp
new file mode 100644
index 0000000..420a1d3
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/heap/heap_allocator.hpp
@@ -0,0 +1,45 @@
+#ifndef TEACHOS_ARCH_X86_64_MEMORY_HEAP_HEAP_ALLOCATOR_HPP
+#define TEACHOS_ARCH_X86_64_MEMORY_HEAP_HEAP_ALLOCATOR_HPP
+
+#include <cstdint>
+
+namespace teachos::arch::memory::heap
+{
+  std::size_t constexpr KERNEL_HEAP_START = 0x100000000;
+  std::size_t constexpr KERNEL_HEAP_SIZE = 100 * 1024;
+  std::size_t constexpr USER_HEAP_START = 0x100019000;  // Starts directly after kernel heap
+  std::size_t constexpr USER_HEAP_SIZE = 100 * 1024;
+
+  /**
+   * @brief Heap allocator interface containing methods required to allocate and deallocate heap memory areas
+   */
+  struct heap_allocator
+  {
+    /**
+     * @brief Virtual default destructor, created to ensure that if a pointer to this class is used and deleted, we will
+     * also call the derived base class destructor. Deleting a base class destructor that does not have a virtual
+     * destructor is undefined behaviour, because the derived class destructor originally instantiated with new is never
+     * called. This can cause potential memory leaks, because derived classes can not clean up their internal members as
+     * expected and instead simply leak them
+     */
+    virtual ~heap_allocator() {}
+
+    /**
+     * @brief Allocates the given amount of memory and returns the pointer to the start of the allocatable memory area
+     *
+     * @param size Amount of bytes that should be allocated
+     * @return void* Pointer to the start of the allocatable memory area
+     */
+    virtual auto allocate(std::size_t size) -> void * = 0;
+
+    /**
+     * @brief Deallocates all memory associated with the given pointer address.
+     * Simply deallocates the amount of memory created with the corresponding call to allocate
+     *
+     * @param pointer Previously allocated memory area, that should now be freed
+     */
+    virtual auto deallocate(void * pointer) noexcept -> void = 0;
+  };
+}  // namespace teachos::arch::memory::heap
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_HEAP_HEAP_ALLOCATOR_HPP
diff --git a/arch/x86_64/pre/include/arch/memory/heap/linked_list_allocator.hpp b/arch/x86_64/pre/include/arch/memory/heap/linked_list_allocator.hpp
new file mode 100644
index 0000000..bbbad19
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/heap/linked_list_allocator.hpp
@@ -0,0 +1,120 @@
+#ifndef TEACHOS_ARCH_X86_64_MEMORY_HEAP_LINKED_LIST_ALLOCATOR_HPP
+#define TEACHOS_ARCH_X86_64_MEMORY_HEAP_LINKED_LIST_ALLOCATOR_HPP
+
+#include "arch/memory/heap/heap_allocator.hpp"
+#include "arch/memory/heap/memory_block.hpp"
+
+#include <kstd/mutex.hpp>
+
+namespace teachos::arch::memory::heap
+{
+  /**
+   * @brief Sorted by address list of memory holes (free memory). Uses free holes itself to save the information,
+   * containing the size and pointer to the next hole. Resulting in a singly linked list.
+   */
+  struct linked_list_allocator : heap_allocator
+  {
+    /**
+     * @brief Constructor.
+     *
+     * @param heap_start Start of the allocatable heap area
+     * @param heap_end End of the allocatable heap area (Start + Size)
+     */
+    linked_list_allocator(std::size_t heap_start, std::size_t heap_end);
+
+    /**
+     * @copybrief heap_allocator::allocate
+     *
+     * @note The specified size is used to find a free memory block with the exact same size, meaning we can remove that
+     * free memory block from the free list and simply return its address. Or it has to be big enough to hold the size
+     * and alteast enough memory for another free memory block entry (16 bytes). If the amount of memory of that free
+     * memory block is in between we cannot use it for our allocation, because we could only return it to the user, but
+     * the additional bytes, could not be used to create a free memory block. Additionaly the user couldn't know
+     * they received more memory than wanted. Therefore the memory would simply be unused and because it is neither
+     * allocated nor deallocated would never be indexed by the free memory list. We would therefore permanently loose
+     * that memory, to prevent that allocation into free memory blocks like that are impossible.
+     */
+    auto allocate(std::size_t size) -> void * override;
+
+    auto deallocate(void * pointer) noexcept -> void override;
+
+  private:
+    /**
+     * @brief Returns the smallest allocatable block of heap memory.
+     *
+     * @return Smallest allocatable block of heap memory.
+     */
+    auto constexpr min_allocatable_size() -> std::size_t { return sizeof(memory_block); }
+
+    /**
+     * @brief Removes a free memory block from the free list and returns its address so the caller can allocate into it.
+     *
+     * @param previous_block Free memory block before the block to allocate in our heap memory. Was to small to
+     * allocate the required size into.
+     * @param current_block Free memory block we want to remove from the free list and return for the allocation.
+     *
+     * @return Previous start address of the memory block we removed, because it can now be used for the allocation.
+     */
+    auto remove_free_memory_block(memory_block * previous_block, memory_block * current_block) -> void *;
+
+    /**
+     * @brief Splits the given free memory block into two, where the latter block keeps being free and the first
+     * part will be used for the allocation.
+     *
+     * @param previous_block Free memory block before the block to allocate in our heap memory. Was to small to
+     * allocate the required size into.
+     * @param current_block Free memory block we want to split into a size part for the allocation and the rest for
+     * future allocations.
+     * @param size Size we want to allocate at the start of the free memory block.
+     *
+     * @return Previous start address of the memory block we just split, because it can now be used for the allocation.
+     */
+    auto split_free_memory_block(memory_block * previous_block, memory_block * current_block, std::size_t size)
+        -> void *;
+
+    /**
+     * @brief Removes a free memory block from the free list and returns its address so the caller can allocate into it.
+     *
+     * @param previous_block Free memory block before the block to allocate in our heap memory. Was to small to
+     * allocate the required size into.
+     * @param current_block Free memory block we want to remove from the free list and return for the allocation.
+     * @param new_block Replaces the current block with the given new block can be nullptr, meaning the free list will
+     * end here.
+     *
+     * @return Previous start address of the memory block we removed, because it can now be used for the allocation.
+     */
+    auto replace_free_memory_block(memory_block * previous_block, memory_block * current_block,
+                                   memory_block * new_block) -> void *;
+
+    /**
+     * @brief Combines multiple free memory blocks into one if they are adjacent.
+     *
+     * @note The internal algorithm for recombination functions like this:
+     * 1. Check if there is even any memory left, if not the first entry of our linked list should be a nullptr and
+     * we can therefore set the first entry to our newly created entry. This entry is created in the now deallocated
+     * memory area.
+     * 2. If there are more blocks but neither the previous nor the current block are adjacent, we simply create a
+     * new free memory block of the given size and set the previous next to our block and the next of our block to
+     * the current block.
+     * 3. If the current block is adjacent the start address of the newly created block stays the same, but the size
+     * increases by the amount in the current memory block header. After reading it we also clear the header.
+     * 4. If the previous block is adjacent the size of the previous block simply increases to include the given
+     * size as well.
+     * 5. If the previous block is directly in our start address, so they overlap then it has to mean some or all of
+     * the region we are trying to deallocate has been freed before. Which would result in a double free therefore
+     * we halt the execution of the program.
+     *
+     * @param previous_block Free memory block before the block to deallocate in our heap memory.
+     * @param current_block Free memory block after the block to deallocate in our heap memory.
+     * @param pointer Block to deallocate.
+     * @param size Size of the block we want to deallocate.
+     */
+    auto coalesce_free_memory_block(memory_block * previous_block, memory_block * current_block, void * pointer,
+                                    std::size_t size) -> void;
+
+    memory_block * first;  ///< First free entry in our memory.
+    kstd::mutex mutex;     ///< Mutex to ensure only one thread calls allocate or deallocate at once.
+  };
+}  // namespace teachos::arch::memory::heap
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_HEAP_LINKED_LIST_ALLOCATOR_HPP
diff --git a/arch/x86_64/pre/include/arch/memory/heap/memory_block.hpp b/arch/x86_64/pre/include/arch/memory/heap/memory_block.hpp
new file mode 100644
index 0000000..9d1fb02
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/heap/memory_block.hpp
@@ -0,0 +1,39 @@
+#ifndef TEACHOS_ARCH_X86_64_MEMORY_HEAP_MEMORY_BLOCK_HPP
+#define TEACHOS_ARCH_X86_64_MEMORY_HEAP_MEMORY_BLOCK_HPP
+
+#include <cstdint>
+
+namespace teachos::arch::memory::heap
+{
+  /**
+   * @brief Block containing free memory, pointing to the next free hole (nullptr) if there is none.
+   * Forms a singly linked list of free memory blocks that we can callocate memory into.
+   */
+  struct memory_block
+  {
+    /**
+     * @brief Constructor. Clears all memory from the place it was allocated until the end (address +
+     * size).
+     *
+     * @param size Amount of free memory of this specific hole.
+     * @param next Optional pointer to the next free memory.
+     */
+    [[gnu::section(".user_text")]]
+    memory_block(std::size_t size, memory_block * next);
+
+    /**
+     * @brief Destructor. Clears all internal memory.
+     *
+     * @note Used so the memory can be reused to construct other classes into, without having the old values.
+     * Required because we cannot call delete, because it causes "undefined reference to `sbrk`".
+     */
+    [[gnu::section(".user_text")]]
+    ~memory_block();
+
+    std::size_t size;     ///< Amount of free memory this hole contains, has to always be atleast 16 bytes to hold the
+                          ///< size variable and the pointer to the next hole.
+    memory_block * next;  ///< Optional pointer to the next free memory, holds nullptr if there is none.
+  };
+}  // namespace teachos::arch::memory::heap
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_HEAP_MEMORY_BLOCK_HPP
diff --git a/arch/x86_64/pre/include/arch/memory/heap/user_heap_allocator.hpp b/arch/x86_64/pre/include/arch/memory/heap/user_heap_allocator.hpp
new file mode 100644
index 0000000..3b47f15
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/heap/user_heap_allocator.hpp
@@ -0,0 +1,149 @@
+#ifndef TEACHOS_ARCH_X86_64_MEMORY_HEAP_USER_HEAP_ALLOCATOR_HPP
+#define TEACHOS_ARCH_X86_64_MEMORY_HEAP_USER_HEAP_ALLOCATOR_HPP
+
+#include "arch/memory/heap/memory_block.hpp"
+
+// #include <kstd/mutex.hpp>
+#include <kstd/mutex.hpp>
+#include <optional>
+
+namespace teachos::arch::memory::heap
+{
+  /**
+   * @brief Sorted by address list of memory holes (free memory). Uses free holes itself to save the information,
+   * containing the size and pointer to the next hole. Resulting in a singly linked list.
+   */
+  struct user_heap_allocator
+  {
+    /**
+     * @brief Constructor.
+     */
+    user_heap_allocator() = default;
+
+    /**
+     * @copybrief heap_allocator::allocate
+     *
+     * @note The specified size is used to find a free memory block with the exact same size, meaning we can remove that
+     * free memory block from the free list and simply return its address. Or it has to be big enough to hold the size
+     * and alteast enough memory for another free memory block entry (16 bytes). If the amount of memory of that free
+     * memory block is in between we cannot use it for our allocation, because we could only return it to the user, but
+     * the additional bytes, could not be used to create a free memory block. Additionaly the user couldn't know
+     * they received more memory than wanted. Therefore the memory would simply be unused and because it is neither
+     * allocated nor deallocated would never be indexed by the free memory list. We would therefore permanently loose
+     * that memory, to prevent that allocation into free memory blocks like that are impossible.
+     */
+    [[gnu::section(".user_text")]]
+    auto allocate(std::size_t size) -> void *;
+
+    /**
+     *  @copybrief heap_allocator::deallocate
+     */
+    [[gnu::section(".user_text")]]
+    auto deallocate(void * pointer) noexcept -> void;
+
+  private:
+    /**
+     * @brief Returns the smallest allocatable block of heap memory.
+     *
+     * @return Smallest allocatable block of heap memory.
+     */
+    [[gnu::section(".user_text")]] auto constexpr min_allocatable_size() -> std::size_t { return sizeof(memory_block); }
+
+    /**
+     * @brief Checks if the given memory block is big enough and if it is allocates into the current block.
+     *
+     * @note Adjusts the link of the previous memory block to the new smaller remaining block. If the allocation used
+     * the complete block instead the previous block will point to the next block of the current memroy block that was
+     * used for the allocation.
+     *
+     * @return Allocated usable memory area.
+     */
+    [[gnu::section(".user_text")]] auto
+    allocate_into_memory_block_if_big_enough(memory_block * current, memory_block * previous, std::size_t total_size)
+        -> std::optional<void *>;
+
+    /**
+     * @brief Special functionality fo the user heap allocator. Which will result in it being expanded by a syscall with
+     * addtionally 100 KiB, which are mapped into the page table. Will always work until there is no physical memory
+     * left.
+     *
+     * @return Start of the newly with syscall allocated free memory block. Nullptr if the syscall failed.
+     */
+    [[gnu::section(".user_text")]] auto expand_heap_if_full() -> memory_block *;
+
+    /**
+     * @brief Removes a free memory block from the free list and returns its address so the caller can allocate into it.
+     *
+     * @param previous_block Free memory block before the block to allocate in our heap memory. Was to small to
+     * allocate the required size into.
+     * @param current_block Free memory block we want to remove from the free list and return for the allocation.
+     *
+     * @return Previous start address of the memory block we removed, because it can now be used for the allocation.
+     */
+    [[gnu::section(".user_text")]]
+    auto remove_free_memory_block(memory_block * previous_block, memory_block * current_block) -> void *;
+
+    /**
+     * @brief Splits the given free memory block into two, where the latter block keeps being free and the first
+     * part will be used for the allocation.
+     *
+     * @param previous_block Free memory block before the block to allocate in our heap memory. Was to small to
+     * allocate the required size into.
+     * @param current_block Free memory block we want to split into a size part for the allocation and the rest for
+     * future allocations.
+     * @param size Size we want to allocate at the start of the free memory block.
+     *
+     * @return Previous start address of the memory block we just split, because it can now be used for the allocation.
+     */
+    [[gnu::section(".user_text")]]
+    auto split_free_memory_block(memory_block * previous_block, memory_block * current_block, std::size_t size)
+        -> void *;
+
+    /**
+     * @brief Removes a free memory block from the free list and returns its address so the caller can allocate into it.
+     *
+     * @param previous_block Free memory block before the block to allocate in our heap memory. Was to small to
+     * allocate the required size into.
+     * @param current_block Free memory block we want to remove from the free list and return for the allocation.
+     * @param new_block Replaces the current block with the given new block can be nullptr, meaning the free list will
+     * end here.
+     *
+     * @return Previous start address of the memory block we removed, because it can now be used for the allocation.
+     */
+    [[gnu::section(".user_text")]]
+    auto replace_free_memory_block(memory_block * previous_block, memory_block * current_block,
+                                   memory_block * new_block) -> void *;
+
+    /**
+     * @brief Combines multiple free memory blocks into one if they are adjacent.
+     *
+     * @note The internal algorithm for recombination functions like this:
+     * 1. Check if there is even any memory left, if not the first entry of our linked list should be a nullptr and
+     * we can therefore set the first entry to our newly created entry. This entry is created in the now deallocated
+     * memory area.
+     * 2. If there are more blocks but neither the previous nor the current block are adjacent, we simply create a
+     * new free memory block of the given size and set the previous next to our block and the next of our block to
+     * the current block.
+     * 3. If the current block is adjacent the start address of the newly created block stays the same, but the size
+     * increases by the amount in the current memory block header. After reading it we also clear the header.
+     * 4. If the previous block is adjacent the size of the previous block simply increases to include the given
+     * size as well.
+     * 5. If the previous block is directly in our start address, so they overlap then it has to mean some or all of
+     * the region we are trying to deallocate has been freed before. Which would result in a double free therefore
+     * we halt the execution of the program.
+     *
+     * @param previous_block Free memory block before the block to deallocate in our heap memory.
+     * @param current_block Free memory block after the block to deallocate in our heap memory.
+     * @param pointer Block to deallocate.
+     * @param size Size of the block we want to deallocate.
+     */
+    [[gnu::section(".user_text")]]
+    auto coalesce_free_memory_block(memory_block * previous_block, memory_block * current_block, void * pointer,
+                                    std::size_t size) -> void;
+
+    memory_block * first = {};  ///< First free entry in our memory.
+    kstd::mutex mutex = {};     ///< Mutex to ensure only one thread calls allocate or deallocate at once.
+  };
+}  // namespace teachos::arch::memory::heap
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_HEAP_USER_HEAP_ALLOCATOR_HPP
diff --git a/arch/x86_64/pre/include/arch/memory/main.hpp b/arch/x86_64/pre/include/arch/memory/main.hpp
new file mode 100644
index 0000000..d51815f
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/main.hpp
@@ -0,0 +1,30 @@
+#ifndef TEACHOS_ARCH_X86_64_MEMORY_MAIN_HPP
+#define TEACHOS_ARCH_X86_64_MEMORY_MAIN_HPP
+
+#include "arch/memory/paging/page_entry.hpp"
+
+#include <cstdint>
+
+namespace teachos::arch::memory
+{
+
+  /**
+   * @brief Maps a heap section to a page.
+   *
+   * @param heap_start Start-address of the heap.
+   * @param heap_size Size of the heap.
+   * @param additional_flags Additional flags to apply to the page entry.
+   */
+  auto remap_heap(std::size_t heap_start, std::size_t heap_size, paging::entry::bitset additional_flags) -> void;
+
+  /**
+   * @brief Initializes memory management.
+   *
+   * @note Enables the necessary register flags and remaps the kernel,
+   * elf_sections, vga_text and the heap.
+   */
+  auto initialize_memory_management() -> void;
+
+}  // namespace teachos::arch::memory
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_MAIN_HPP
diff --git a/arch/x86_64/pre/include/arch/memory/multiboot/elf_symbols_section.hpp b/arch/x86_64/pre/include/arch/memory/multiboot/elf_symbols_section.hpp
new file mode 100644
index 0000000..348c159
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/multiboot/elf_symbols_section.hpp
@@ -0,0 +1,170 @@
+#ifndef TEACHOS_ARCH_X86_64_MEMORY_MULTIBOOT_ELF_SYBOLS_SECTION_HPP
+#define TEACHOS_ARCH_X86_64_MEMORY_MULTIBOOT_ELF_SYBOLS_SECTION_HPP
+
+// #include "arch/memory/multiboot/info.hpp"
+// #include "arch/stl/container.hpp"
+// #include "arch/stl/contiguous_pointer_iterator.hpp"
+
+#include <bitset>
+#include <cstdint>
+
+namespace teachos::arch::memory::multiboot
+{
+  /**
+   * @brief Defines all elf section types an elf section header can have.
+   *
+   * @note See https://docs.oracle.com/cd/E19683-01/816-1386/chapter6-94076/index.html for more information.
+   */
+  enum struct elf_section_type : uint32_t
+  {
+    INACTIVE,                       ///< (SHT_NULL) Unused, meaning all values are zeroed out.
+    PROGRAMM,                       ///< (SHT_PROGBITS) Program data (DATA, CODE).
+    SYMBOL_TABLE,                   ///< (SHT_SYMBTAB) Contains actual entries pointed to in symbol hash table.
+    STRING_TABLE,                   ///< (SHT_STRTAB) Contains symbols, section and debugging null-terminated strings.
+    RELOCATION_ENTRY_WITH_ADDENDS,  ///< (SHT_RELA) Only used on 64 bit systems.
+    SYMBOL_HASH_TABLE,              ///< (SHT_HASH) Hash table used by dynamic linker to locate symbols.
+    DYNAMIC,                        ///< (SHT_DYNAMIC) Contains dynamic linking information.
+    NOTE,                           ///< (SHT_NOTE) Stores information that marks files in some way.
+    EMPTY,                          ///< (SHT_NOBITS) Program data section, that occupies no space in the file (.bss).
+    RELOCATION_ENTRY_WITHOUT_ADDENDS,   ///< (SHT_REL) Only used on 32 bit systems.
+    UNSPECIFIED,                        ///< (SHT_SHLIB) Reserved but has unspecified semantics.
+    DYNAMIC_SYMBOL_TABLE,               ///< (SHT_DYNSYM) Holds minimal set of symbols adequate for dynamic linking.
+    INITALIZATION_FUNCTION_ARRAY = 14,  ///< (SHT_INIT_ARRAY) Array of pointers to intialization functions () -> void.
+    TERMINATION_FUNCTION_ARRAY,         ///< (SHT_FINI_ARRAY) Array of pointers to termination functions () -> void.
+    PRE_INITALIZATION_FUNCTION_ARRAY    ///< (SHT_PRE_INIT_ARRAY) Array of pointers to functions invoked before other
+                                        ///< initalization functions () -> void.
+  };
+
+  /**
+   * @brief Defines helper function for all states that the elf section flags of an elf section header can
+   * have.
+   *
+   * @note See https://docs.oracle.com/cd/E19683-01/816-1386/chapter6-94076/index.html for more information.
+   */
+  struct elf_section_flags
+  {
+    /**
+     * @brief Possible set bits in our underlying std::bitset and the meaning when they are set.
+     */
+    enum bitset : uint32_t
+    {
+      WRITABLE = 1U << 0U,         ///< (SHF_WRITE) Section is writable at runtime. If it isn't then the section
+                                   ///< is assumed to be READONLY and only that flag is shown in the objdump.
+      OCCUPIES_MEMORY = 1U << 1U,  ///< (SHF_ALLOC) Section occupies memory during execution.
+                                   ///< ALLOC flag is shown in the objdump.
+      EXECUTABLE_CODE = 1U << 2U,  ///< (SHF_EXECINSTR) Section is executable. CODE flag is shown in the object dump.
+      DUPLICATE_DATA = 1U << 4U,   ///< (SHF_MERGE) Section might be merged with another section.
+      CONTAINS_STRING = 1U << 5U,  ///< (SHF_STRINGS) Section contains null-terminated strings.
+      SECTION_HEADER_INFO_IS_SECTION_HEADER_TABLE_INDEX =
+          1U << 6U,  ///< (SHF_INFO_LINK) Section contains the section header table index in the (sh_info)
+                     ///< additional_information variable.
+      PRESERVE_ORDERING_AFTER_COMBINATION =
+          1U << 7U,  ///< (SHF_LINK_ORDER) Section preserves order after combining with another section.
+      REQUIRES_SPECIAL_OS_PROCESSING =
+          1U << 8U,  ///< (SHF_OS_NONCONFORMING) Section requires non-standard OS specific handling of its code or
+                     ///< data, which does not confirm to standard ELF specifications.
+      SECTION_GROUP_MEMBER = 1U << 9U,      ///< (SHF_GROUP) Section is a member of a section group.
+      HOLDS_THREAD_LOCAL_DATA = 1U << 10U,  ///< (SHF_TLS) Section holds thread-local data.
+      COMPRESSED = 1U << 11U,               ///< (SHF_COMPRESSED) Section contains compressed data.
+      SPECIAL_ORDERING_REQUIREMENTS =
+          1U << 30U,  ///< (SHF_ORDERED) Section has special ordering requirements, meaning it
+                      ///< should be ordered in relation to other sections of the same type.
+      EXCLUDED_UNLESS_REFERENCED_OR_ALLOCATED = 1U << 31U,  ///< (SHF_EXCLUDE)Section is excluded unless referenced or
+                                                            ///< allocated, used for LTO (Link-Time Optimizations).
+    };
+
+    /**
+     * @brief Constructor.
+     *
+     * @param flags Actual value read from the elf section header, which should be converted into a std::bitset, to
+     * allow reading the state of single bits more easily.
+     */
+    explicit elf_section_flags(uint64_t flags)
+        : flags(flags)
+    {
+      // Nothing to do
+    }
+
+    /**
+     * @brief Checks if the given std::bitset is a subset or equivalent to the underlying std::bitset.
+     *
+     * @note Meaning that all bits that are set in the given std::bitset also have to be set in the underlyng
+     * std::bitset. Any additional bits that are set are not relevant.
+     *
+     * @param other Flags that we want to compare against and check if the underlying std::bitset has the same bits set.
+     * @return Whether the given flags are a subset or equivalent with the underlying std::bitset.
+     */
+    auto contains_flags(std::bitset<64U> other) const -> bool;
+
+    /**
+     * @brief Allows to compare the underlying std::bitset of two instances.
+     *
+     * @param other Other instance that we want to compare with.
+     * @return Whether the underlying std::bitset of both types is the same.
+     */
+    auto operator==(elf_section_flags const & other) const -> bool = default;
+
+  private:
+    std::bitset<64U> flags;  ///< Underlying bitset used to read the flags from. Bits 21 - 28 are reserved for operating
+                             ///< system specific semantics and bits 29 - 32 are reserved for processor specific
+                             ///< semantics. Bits 33 - 64 are unused for compatability with ELF32.
+  };
+
+  /**
+   * @brief Defines the data included in a section header, where each section has exactly one section header.
+   *
+   * @note See https://refspecs.linuxbase.org/elf/gabi4+/ch4.sheader.html for more information.
+   */
+  struct elf_section_header
+  {
+    uint32_t name_table_index;  ///< Index into the section header string table, specifies the name of the section.
+    elf_section_type type;      ///< Categorizes the sections content and semantics.
+    elf_section_flags flags;    ///< 1-bit flgas that describe section attributes.
+    uint64_t physical_address;  ///< If section appears in memory image of a process, gives address at which the
+                                ///< sections first byte should reside, otherwise 0.
+    uint64_t file_offset;       ///< Offset from the beginning of the file to the first byte in the section. SHT_NOBITS
+                           ///< contains the conceptual placement instead (because it occupies no space in the file).
+    uint64_t section_size;   ///< Complete section size in bytes, SHT_NOBITS may have non-zero value but will always
+                             ///< occupy no space in the file.
+    uint32_t other_section;  ///< Section header table index link, behaviour varies on type
+                             ///< https://refspecs.linuxbase.org/elf/gabi4+/ch4.sheader.html#sh_link.
+    uint32_t additional_information;  ///< Extra information, behaviour varies on type
+                                      ///< https://refspecs.linuxbase.org/elf/gabi4+/ch4.sheader.html#sh_link.
+    uint64_t address_alignment;  ///< Possible address alignment constraints. Value of virutal_address must be 0 % value
+                                 ///< of address_alignment. Value 0 or 1 mean no alignment constraints.
+    uint64_t fixed_table_entry_size;  ///< If sections holds table with fixed-sized entries, this gives the size in
+                                      ///< bytes of each entry.
+
+    /**
+     * @brief Detect whether a section header is inactive or not, should always be the case for the first entry in the
+     * sections table.
+     *
+     * @return Whether the current section header is actually null or not, requires all fields besides section_size and
+     * other_section to contain 0.
+     */
+    auto is_null() const -> bool;
+  };
+
+  // /**
+  //  * @brief Defines an entry in the multi_boot_tag array of the multi_boot_info struct, of type
+  //  * multi_boot_tag_type::ELF_SECTIONS.
+  //  *
+  //  * @note The first section in the sections array will always be INACTIVE, there can only ever be one DYNAMIC
+  //  section
+  //  * and only either one DYNAMIC_SYMBOL_TABLE or SYMBOL_TABLE.
+  //  */
+  // struct elf_symbols_section_header
+  // {
+  //   tag info;                     ///< Basic multi_boot_tag information.
+  //   uint32_t number_of_sections;  ///< Number of sections in the sections array.
+  //   uint32_t entry_size;          ///< Size of each entry in the sections array.
+  //   uint32_t section_index;       ///< Index to the string table used for symbol names.
+  //   std::byte end;                ///< Marks the end of the tag, used to mark the beginning of any additional data.
+  //                                 ///< contained in the section, to ensure byte alignment is actually 4 byte.
+  // };
+
+  // using elf_section_header_container = stl::container<stl::contiguous_pointer_iterator<elf_section_header>>;
+
+}  // namespace teachos::arch::memory::multiboot
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_MULTIBOOT_ELF_SYBOLS_SECTION_HPP
diff --git a/arch/x86_64/pre/include/arch/memory/multiboot/reader.hpp b/arch/x86_64/pre/include/arch/memory/multiboot/reader.hpp
new file mode 100644
index 0000000..c5464cb
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/multiboot/reader.hpp
@@ -0,0 +1,58 @@
+#ifndef TEACHOS_ARCH_X86_64_MEMORY_MULTIBOOT_READER_HPP
+#define TEACHOS_ARCH_X86_64_MEMORY_MULTIBOOT_READER_HPP
+
+// #include "arch/memory/multiboot/elf_symbols_section.hpp"
+// #include "arch/memory/multiboot/memory_map.hpp"
+
+#include "arch/memory/multiboot/elf_symbols_section.hpp"
+
+#include <cstdint>
+#include <multiboot2/information.hpp>
+#include <span>
+
+namespace teachos::arch::memory::multiboot
+{
+  /**
+   * @brief Contains all relevant information to map and allocate memory that is read from the multiboot2 information
+   * structure.
+   */
+  struct memory_information
+  {
+    std::size_t kernel_start;     ///< Start address of the kernel code in memory.
+    std::size_t kernel_end;       ///< End address of the kernel code in memory.
+    multiboot2::elf_symbols;      ///< Contains non-owning pointers to all kernel sections.
+    std::size_t multiboot_start;  ///< Start address of the multiboot code in memory.
+    std::size_t multiboot_end;    ///< End address of the multiboot code in memory.
+    // std::sp
+    // memory_area_container areas;            ///< Contains non-owning pointers to all memory areas.
+  };
+
+  /**
+   * @brief Reads the relevant multiboot2 information data from memory.
+   *
+   * @note This is done using the multiboot_information_pointer, which marks the start of the multiboot2 data. The
+   * indivdual headers we have to read are 8 byte aligned, whereas the data contained in those headers does not have to
+   * be. All sections that are read additionaly receive some sanity to ensure the read address is actually pointing to
+   * the expected structure, if they are not this method will assert.
+   *
+   * The memory_information variables are calcualted like this:
+   * - kernel_start: Calculated by getting the lowest address specified in the elf symbols headers.
+   * - kernel_end: Calculated by getting the highest address specified in the elf symbols headers and adding the length
+   * of that section.
+   * - multiboot_start: Calcualted by simply getting the value of the multiboot information pointer, because it already
+   * contains the address pointint to the start of the multiboot2 data.
+   * - multiboot_end: Calcualted by getting the value of the multiboot information pointer and adding the total size of
+   * the complete multiboot2 data
+   * - memory_areas: Calculated by simply accessing the address of the entries variable in the memory map header
+   * structure.
+   * - area_count: Calculated by subtracing the memory map header size from the total tag size, which results in the
+   * remaining size (size of the entries array), this size is then divided by the size of one entry in that array, which
+   * should be 24 bytes.
+   *
+   * @return Relevant data read from multiboot2.
+   */
+  auto read_multiboot2() -> memory_information;
+
+}  // namespace teachos::arch::memory::multiboot
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_MULTIBOOT_READER_HPP
diff --git a/arch/x86_64/pre/include/arch/memory/paging/active_page_table.hpp b/arch/x86_64/pre/include/arch/memory/paging/active_page_table.hpp
new file mode 100644
index 0000000..f68d8b6
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/paging/active_page_table.hpp
@@ -0,0 +1,206 @@
+#ifndef TEACHOS_ARCH_X86_64_MEMORY_PAGING_ACTIVE_PAGE_TABLE_HPP
+#define TEACHOS_ARCH_X86_64_MEMORY_PAGING_ACTIVE_PAGE_TABLE_HPP
+
+#include "arch/exception_handling/assert.hpp"
+#include "arch/kernel/cpu/tlb.hpp"
+#include "arch/memory/allocator/concept.hpp"
+#include "arch/memory/paging/virtual_page.hpp"
+
+#include <array>
+#include <bitset>
+#include <optional>
+
+namespace teachos::arch::memory::paging
+{
+  /**
+   * @brief Currently actively by the CPU used level 4 page table, is used to ensure there is only ever one valid
+   * instance and it cannot be copied or constructed again.
+   */
+  struct active_page_table
+  {
+    /**
+     * @brief Creates a single instance of an active level 4 page table table and returns the created instance or
+     * alternatively returns the previously created instance instead. The instance is owned by this method and is
+     * static, meaning it lives on for the complete lifetime of the program.
+     *
+     * @return Active single unique instance of the level 4 page table.
+     */
+    static auto create_or_get() -> active_page_table &;
+
+    /**
+     * @brief Index operator overload to access specific mutable entry directy of the level 4 page table.
+     *
+     * @param index Index of the entry we want to access and only read.
+     * @return Entry at the given table index.
+     */
+    auto operator[](std::size_t index) -> entry &;
+
+    /**
+     * @brief Translates virtual address into corresponding physical address. Calls translate_page under the hood.
+     *
+     * @param address Virtual address we want to translate into physical one.
+     * @return Physical address corresponding to the provided virtual address.
+     */
+    auto translate_address(virtual_address address) -> std::optional<allocator::physical_address>;
+
+    /**
+     * @brief Translates page into physical frame, will first attempt to parse normally using default page size and if
+     * it failed attempt to parse using huge pages.
+     *
+     * @param page Page to translate into physical frame.
+     * @return Physical frame corresponding to the provided virtual page.
+     */
+    auto translate_page(virtual_page page) -> std::optional<allocator::physical_frame>;
+
+    /**
+     * @brief Translates huge page into actual physical frame.
+     *
+     * @param page Page to translate into physical frame.
+     * @return Physical frame corresponding to the provided virtual page.
+     */
+    auto translate_huge_page(virtual_page page) -> std::optional<allocator::physical_frame>;
+
+    /**
+     * @brief Maps a virtual page to a physical frame in the page table with the specified flags.
+     *
+     * @note Allocates and maps an entry in every page level if it does not exists yet down to level 1. If the level 1
+     * page table already exists it halts execution instead.
+     *
+     * @tparam T Type constraint of the allocator, being that is follows the given concept and contains an allocate and
+     * deallocate method.
+     * @param allocator Reference to an allocator following the FrameAllocator concept, which is used to allocate
+     * entries when a new page table is required.
+     * @param page Virtual page that is being mapped.
+     * @param frame Physical frame that the virtual page will be mapped to.
+     * @param flags A bitset of flags that configure the page table entry for this mapping.
+     */
+    template<allocator::FrameAllocator T>
+    auto map_page_to_frame(T & allocator, virtual_page page, allocator::physical_frame frame, std::bitset<64U> flags)
+        -> void
+    {
+      auto current_handle = active_handle;
+
+      for (auto level = page_table_handle::LEVEL4; level != page_table_handle::LEVEL1; --level)
+      {
+        current_handle = current_handle.next_table_or_create(allocator, page.get_level_index(level), flags);
+      }
+
+      auto & level1_entry = current_handle[page.get_level_index(page_table_handle::LEVEL1)];
+      arch::exception_handling::assert(!level1_entry.contains_flags(entry::HUGE_PAGE),
+                                       "[Page Mapper] Unable to map huge pages");
+      arch::exception_handling::assert(level1_entry.is_unused(), "[Page Mapper] Page table entry is already used");
+      level1_entry.set_entry(frame, flags.to_ulong() | entry::PRESENT);
+    }
+
+    /**
+     * @brief Allocates the next free frame and then uses that frame to call map_page_to_frame.
+     *
+     * @see map_page_to_frame
+     */
+    template<allocator::FrameAllocator T>
+    auto map_page_to_next_free_frame(T & allocator, virtual_page page, std::bitset<64U> flags) -> void
+    {
+      auto const frame = allocator.allocate_frame();
+      exception_handling::assert(frame.has_value(), "[Page mapper] Out of memory exception");
+      map_page_to_frame(allocator, page, frame.value(), flags);
+    }
+
+    /**
+     * @brief Gets the corresponding page the given frame has to be contained in and uses that to call
+     * map_page_to_frame.
+     *
+     * @see map_page_to_frame
+     */
+    template<allocator::FrameAllocator T>
+    auto identity_map(T & allocator, allocator::physical_frame frame, std::bitset<64U> flags) -> void
+    {
+      auto const page = virtual_page::containing_address(frame.start_address());
+      map_page_to_frame(allocator, page, frame, flags);
+    }
+
+    /**
+     * @brief Unmaps the virtual page from the previously mapped to physical frame and resets the flags.
+     *
+     *  @note For the unmap function to deallocates and unmaps correctly, the entry in every page level if this page was
+     * the last one up to level 4 should be unmapped and ensured to clear the Translation Lookaside Buffer, so that the
+     * unmapped value is removed from cache as well. This is currently not done and instead we only dallocate and unmap
+     * the level 1 page table entry, this is the case because it conflicts with our recursive mapping for the temporary
+     * page, which requires the other page table entries to walk to the actual level 4 page table. If we remove all page
+     * table entries beforehand, we therefore can not remap the kernel anymore.
+     *
+     * @tparam T Type constraint of the allocator, being that is follows the given concept and contains an allocate and
+     * deallocate method.
+     * @param allocator Reference to an allocator following the FrameAllocator concept, which is used to allocate
+     * entries when a new page table is required.
+     * @param page Virtual page that is being unmapped.
+     */
+    template<allocator::FrameAllocator T>
+    auto unmap_page(T & allocator, virtual_page page) -> void
+    {
+      exception_handling::assert(translate_page(page).has_value(),
+                                 "[Page Mapper] Attempted to unmap page, which has not been mapped previously");
+
+      auto current_handle = active_handle;
+
+      for (auto level = page_table_handle::LEVEL4; level != page_table_handle::LEVEL1; --level)
+      {
+        auto const level_index = page.get_level_index(level);
+        auto const next_handle = current_handle.next_table(level_index);
+        // The next table method failed even tough the page has to be mapped already, because translate_page did not
+        // fail. This can only mean that we attempted to unmap a huge page, which is not supported in the first place.
+        exception_handling::assert(next_handle.has_value(), "[Page Mapper] Unable to unmap huge pages");
+        current_handle = next_handle.value();
+      }
+
+      unmap_page_table_entry(allocator, page, current_handle);
+      kernel::cpu::tlb_flush(page.start_address());
+    }
+
+  private:
+    /**
+     * @brief Private constructor should only be used by create or get method, which ensures to create only ever one
+     * instance.
+     *
+     * @param active_handle Handle to the underlying currently active level 4 page table.
+     */
+    active_page_table(page_table_handle active_handle);
+
+    /**
+     * @brief Deleted copy constructor.
+     */
+    active_page_table(active_page_table const &) = delete;
+
+    /**
+     * @brief Deleted copy assignment operator.
+     */
+    active_page_table & operator=(active_page_table const &) = delete;
+
+    /**
+     * @brief Unmaps specific page at the current internal handle level.
+     *
+     * @tparam T Type constraint of the allocator, being that is follows the given concept and contains an allocate and
+     * deallocate method.
+     * @param allocator Reference to an allocator following the FrameAllocator concept, which is used to allocate
+     * entries *when a new page table is required.
+     * @param page Virtual page that is being unmapped.
+     * @param handle Page Table handle we want to access the entry that should be cleared on.
+     */
+    template<allocator::FrameAllocator T>
+    static auto unmap_page_table_entry(T & allocator, virtual_page page, page_table_handle & handle) -> void
+    {
+      auto level_index = page.get_level_index(handle.get_level());
+      auto & entry = handle[level_index];
+      auto const frame = entry.calculate_pointed_to_frame();
+      exception_handling::assert(frame.has_value(),
+                                 "[Page Mapper] Attempted to unmap page, which has not been mapped previously");
+      entry.set_unused();
+      allocator.deallocate_frame(frame.value());
+    }
+
+  public:
+    page_table_handle active_handle;  ///< Underlying active level 4 page table
+  };
+
+}  // namespace teachos::arch::memory::paging
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_PAGING_ACTIVE_PAGE_TABLE_HPP
diff --git a/arch/x86_64/pre/include/arch/memory/paging/inactive_page_table.hpp b/arch/x86_64/pre/include/arch/memory/paging/inactive_page_table.hpp
new file mode 100644
index 0000000..8d96740
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/paging/inactive_page_table.hpp
@@ -0,0 +1,39 @@
+#ifndef TEACHOS_ARCH_X86_64_MEMORY_PAGING_INACTIVE_PAGE_TABLE_HPP
+#define TEACHOS_ARCH_X86_64_MEMORY_PAGING_INACTIVE_PAGE_TABLE_HPP
+
+#include "arch/memory/allocator/physical_frame.hpp"
+#include "arch/memory/paging/active_page_table.hpp"
+#include "arch/memory/paging/temporary_page.hpp"
+
+namespace teachos::arch::memory::paging
+{
+  /**
+   * @brief By the CPU used level 4 page table.
+   */
+  struct inactive_page_table
+  {
+    /**
+     * @brief Constructor.
+     *
+     * @param frame Frame that should be mapped as the level 4 page table.
+     */
+    inactive_page_table(allocator::physical_frame frame);
+
+    /**
+     * @brief Constructor.
+     *
+     * @param frame Frame that should be mapped as the level 4 page table.
+     * @param active_page_table Actual active page table that should be unmapped so we can map a new level 4
+     * page table.
+     * @param temporary_page Temporary page that should be used to map the given frame as the new level 4 page
+     * table.
+     */
+    inactive_page_table(allocator::physical_frame frame, active_page_table & active_page_table,
+                        temporary_page & temporary_page);
+
+    allocator::physical_frame page_table_level_4_frame;  ///< Temporary level 4 page table
+  };
+
+}  // namespace teachos::arch::memory::paging
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_PAGING_INACTIVE_PAGE_TABLE_HPP
diff --git a/arch/x86_64/pre/include/arch/memory/paging/kernel_mapper.hpp b/arch/x86_64/pre/include/arch/memory/paging/kernel_mapper.hpp
new file mode 100644
index 0000000..3afb54b
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/paging/kernel_mapper.hpp
@@ -0,0 +1,180 @@
+#ifndef TEACHOS_ARCH_X86_64_MEMORY_PAGING_KERNEL_MAPPER_HPP
+#define TEACHOS_ARCH_X86_64_MEMORY_PAGING_KERNEL_MAPPER_HPP
+
+#include "arch/kernel/cpu/control_register.hpp"
+#include "arch/memory/paging/active_page_table.hpp"
+#include "arch/memory/paging/inactive_page_table.hpp"
+#include "arch/memory/paging/temporary_page.hpp"
+#include "arch/video/vga/text.hpp"
+
+#include <algorithm>
+#include <array>
+
+namespace teachos::arch::memory::paging
+{
+  /**
+   * @brief Kernel mapper that allows to remap the kernel elf sections in C++.
+   *
+   * @tparam T Contract the allocator that should be used to allocate frames for the remapping process has to fulfill.
+   */
+  template<allocator::FrameAllocator T>
+  struct kernel_mapper
+  {
+    /**
+     * @brief Constructor.
+     *
+     * @param allocator Allocator that should be used to allocate frames for the remapping process.
+     * @param mem_info Information about elf kernel sections required for remapping process.
+     */
+    kernel_mapper(T & allocator, multiboot::memory_information const & mem_info)
+        : allocator(allocator)
+        , mem_info(mem_info)
+    {
+      // Nothing to do
+    }
+
+    /**
+     * @brief Remap the kernel, meaning we map the entire kernel and all of it's elf sections with the correct flags
+     * into memory and then replace the created mapping with the current one.
+     *
+     * @note We have to use a workaround with an
+     * inactive page table, that is not used by the CPU to ensure we are not changign memory that we are using. Because
+     * remapping active kernel memory in the kernel wouldn't work.
+     */
+    auto remap_kernel() -> void
+    {
+      // Set Page Global Enable bit
+      auto cr4 = kernel::cpu::read_control_register(kernel::cpu::control_register::CR4);
+      kernel::cpu::write_control_register(kernel::cpu::control_register::CR4, cr4 | 0x80);
+
+      temporary_page temporary_page{virtual_page{0xCAFEBABE}, allocator};
+      decltype(auto) active_table = active_page_table::create_or_get();
+      auto const frame = allocator.allocate_frame();
+      exception_handling::assert(frame.has_value(),
+                                 "[Kernel Mapper] Frame could not be allocated and therefore kernel not mapped");
+      inactive_page_table new_table{frame.value(), active_table, temporary_page};
+      remap_elf_kernel_sections(new_table, temporary_page, active_table);
+      auto const old_table = switch_active_page_table(new_table);
+      // Turn old level 4 page table, mapped by assembler code into stack guard page.
+      // Only works if the identity mapped page tables by assembler are right above the stack.
+      auto const old_level_4_page =
+          virtual_page::containing_address(old_table.page_table_level_4_frame.start_address());
+      active_table.unmap_page(allocator, old_level_4_page);
+    }
+
+  private:
+    /**
+     * @brief Remaps the kernel elf sections.
+     *
+     * This is done with switching the current level 4 page table recursive
+     * mapping to any unmapped address in memory and then actually mapping the level 4 page table on that address.
+     * Once the remapping process is done we can restore the original recursive mapping with the complete remapped
+     * kernel.
+     *
+     * @note Because we change the entries we also have to ensure we flush the translation lookaside buffer, before we
+     * map the entries.
+     *
+     * @param inactive_table Level 4 page table we temporarily map the kernel into.
+     * @param temporary_page Temporary page that should be used for the mapping process and then
+     * unmapped once finished.
+     * @param active_table Active level 4 page table that has its recursive mapping overwritten temporarily and then
+     * restored once the process is finished.
+     */
+    auto remap_elf_kernel_sections(inactive_page_table & inactive_table, temporary_page & temporary_page,
+                                   active_page_table & active_table) -> void
+    {
+      auto const backup = allocator::physical_frame::containing_address(
+          kernel::cpu::read_control_register(kernel::cpu::control_register::CR3));
+      auto page_table_level4 = temporary_page.map_table_frame(backup, active_table);
+
+      active_table[511].set_entry(inactive_table.page_table_level_4_frame, entry::PRESENT | entry::WRITABLE);
+      kernel::cpu::tlb_flush_all();
+      map_elf_kernel_sections(active_table);
+
+      page_table_level4[511].set_entry(backup, entry::PRESENT | entry::WRITABLE);
+      kernel::cpu::tlb_flush_all();
+      temporary_page.unmap_page(active_table);
+    }
+
+    /**
+     * @brief Switches the current active table pointed to by the CR3 register with another page table that is currently
+     * inactive.
+     *
+     * @param new_table Inactive page table that should now be made active and replace the current active one.
+     * @return The previous active page table.
+     */
+    auto switch_active_page_table(inactive_page_table new_table) -> inactive_page_table
+    {
+      auto const backup = allocator::physical_frame::containing_address(
+          kernel::cpu::read_control_register(kernel::cpu::control_register::CR3));
+      auto const old_table = inactive_page_table{backup};
+
+      auto const new_address = new_table.page_table_level_4_frame.start_address();
+      kernel::cpu::write_control_register(kernel::cpu::control_register::CR3, new_address);
+      return old_table;
+    }
+
+    /**
+     * @brief Maps the required entries according to every elf section and it's contained frames. Additionally each of
+     * thoose frames gets the correct entry flags according to elf section flags.
+     *
+     * @param active_table Active level 4 page table that should be used to map the required elf sections into entries.
+     * Has had its recursive mapping temporarily replaced and points to unmapped place in memory.
+     */
+    auto map_elf_kernel_sections(active_page_table & active_table) -> void
+    {
+      exception_handling::assert(!mem_info.sections.empty(), "[Kernel Mapper] Kernel elf sections empty");
+      std::array<uint64_t, 6U> constexpr USER_SECTION_BASES = {
+          0x102000,  // .boot_bss (Contains statically allocated variables)
+          0x209000,  // .stl_text (Contains code for custom std implementations and standard library code)
+          0x217000,  // .user_text (Contains the actual user code executed)
+          0x21E000,  // .user_data (Contains static user variables)
+
+          0x20A000  // .text (Necessary, because symbols for all template standard library features are placed here if
+                    // they were first used in the Kernel Code Section)
+      };
+
+      for (auto const & section : mem_info.sections)
+      {
+        if (!section.flags.contains_flags(multiboot::elf_section_flags::OCCUPIES_MEMORY))
+        {
+          continue;
+        }
+        exception_handling::assert(section.physical_address % allocator::PAGE_FRAME_SIZE == 0U,
+                                   "[Kernel Mapper] Section must be page aligned");
+        auto const start_frame = allocator::physical_frame::containing_address(section.physical_address);
+        // End address is exclusive, so that it is not part of the section anymore (one past the last frame of this
+        // section). But end frame would now point to the actual last frame and not one past the last frame, therefore
+        // we increment by one to get one past the last frame of this section.
+        auto const end_frame =
+            ++(allocator::physical_frame::containing_address(section.physical_address + section.section_size - 1));
+
+        allocator::frame_container::iterator const begin{start_frame};
+        allocator::frame_container::iterator const end{end_frame};
+        allocator::frame_container const frames{begin, end};
+        entry entry{section.flags};
+
+        if (std::ranges::find(USER_SECTION_BASES, section.physical_address) != USER_SECTION_BASES.end())
+        {
+          entry.set_user_accessible();
+        }
+
+        for (auto const & frame : frames)
+        {
+          active_table.identity_map(allocator, frame, entry.get_flags());
+        }
+      }
+
+      auto const vga_buffer_frame =
+          allocator::physical_frame::containing_address(video::vga::text::DEFAULT_VGA_TEXT_BUFFER_ADDRESS);
+      active_table.identity_map(allocator, vga_buffer_frame, entry::WRITABLE);
+    }
+
+    T & allocator;
+    multiboot::memory_information const &
+        mem_info;  ///< Information about elf kernel sections required for remapping process.
+  };
+
+}  // namespace teachos::arch::memory::paging
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_PAGING_KERNEL_MAPPER_HPP
diff --git a/arch/x86_64/pre/include/arch/memory/paging/page_entry.hpp b/arch/x86_64/pre/include/arch/memory/paging/page_entry.hpp
new file mode 100644
index 0000000..8147c5c
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/paging/page_entry.hpp
@@ -0,0 +1,121 @@
+#ifndef TEACHOS_ARCH_X86_64_MEMORY_PAGING_PAGE_ENTRY_HPP
+#define TEACHOS_ARCH_X86_64_MEMORY_PAGING_PAGE_ENTRY_HPP
+
+#include "arch/memory/allocator/physical_frame.hpp"
+#include "arch/memory/multiboot/elf_symbols_section.hpp"
+
+#include <bitset>
+#include <optional>
+
+namespace teachos::arch::memory::paging
+{
+  /**
+   * @brief Marks a specific entry in an actual page table.
+   */
+  struct entry
+  {
+    /**
+     * @brief Possible set bits in our underlying std::bitset and the meaning when they are set.
+     */
+    enum bitset : uint64_t
+    {
+      PRESENT = 1UL << 0UL,                ///< Page is in memory and therefore present.
+                                           ///< is assumed to be READONLY and only that flag is shown in the objdump.
+      WRITABLE = 1UL << 1UL,               ///< It is possible to write to the page.
+      USER_ACCESSIBLE = 1UL << 2UL,        ///< Page can be accessed in user mode instead of only in kernel mode code.
+      WRITE_THROUGH_CACHING = 1UL << 3UL,  ///< Write to the page go directly to memory instead of the cache.
+      DISABLED_CACHING = 1UL << 4UL,       ///< Page uses caching.
+      ACCESSED = 1UL << 5UL,               ///< Page is currently in use.
+      DIRTY = 1UL << 6UL,                  ///< Page has been writen too.
+      HUGE_PAGE = 1UL << 7UL,  ///< Page is huge (2 MiB page size in P2 page table and 1 GiB in P3 page table,
+                               ///< instead of 4 KiB). Has to be false for P1 and P4 page tables.
+      GLOBAL = 1UL << 8UL,     ///< Page is not flushed from caches on address space switches (PGE bit of CR4 register
+                               ///< has to be set)
+      EXECUTING_CODE_FORBIDDEN =
+          1UL << 63UL,  ///< Page is forbidden from executing code (NXE bit in the EFER register has to be set)
+    };
+
+    /**
+     * @brief Defaulted constructor.
+     */
+    entry() = default;
+
+    /**
+     * @brief Creates a new entry object from a 64bit address. Should follow the scheme where bit index 12 - 51 are the
+     * actual address and the other bits are flags.
+     *
+     * @param flags Flags that will be passed to underlying std::bitset.
+     */
+    explicit entry(uint64_t flags);
+
+    /**
+     * @brief Creates a new entry converting the given elf section flags into the corresponding correct entry flags.
+     *
+     * @note Enables us to set the correct flags on a entry depending on which elf section it is contained in. For
+     * example entries of .text sections should be executable and read only or entries of .data sections should be
+     * writable but not executable.
+     *
+     * @param elf_flags Elf section flags we want to convert into entry flags.
+     */
+    explicit entry(multiboot::elf_section_flags elf_flags);
+
+    /**
+     * @brief Whether the current page is unused, meaning the underlying std::bitset is 0.
+     *
+     * @return Current page is in memory.
+     */
+    auto is_unused() const -> bool;
+
+    /**
+     * @brief Marks the page as unused, meaning the underlying std::bitset is set to 0.
+     */
+    auto set_unused() -> void;
+
+    /**
+     * @brief Marks the page as accessible in User mode, meaning the underlying std::bitset has the 2nd bit aditonally
+     * set.
+     */
+    auto set_user_accessible() -> void;
+
+    /**
+     * @brief Calculates the physical frame this entry is pointing too, can be null if the page is not present in
+     * memory.
+     *
+     * @return Calculated physical frame entry is pointing too.
+     */
+    auto calculate_pointed_to_frame() const -> std::optional<allocator::physical_frame>;
+
+    /**
+     * @brief Copies the address and flags from the given physical frame into the underlying std::bitset
+     *
+     * @param frame Physical frame that contains the address we want to copy into our underlying std::bitset.
+     * @param additional_flags Entry flags which will be copied into our underlying std::bitset.
+     */
+    auto set_entry(allocator::physical_frame frame, std::bitset<64U> additional_flags) -> void;
+
+    /**
+     * @brief Checks if the given std::bitset is a subset or equivalent to the underlying std::bitset.
+     *
+     * @note Meaning that all bits that are set in the given std::bitset also have to be set in the underlyng
+     * std::bitset. Any additional bits that are set are not relevant.
+     *
+     * @param other Flags that we want to compare against and check if the underlying std::bitset has the same bits set.
+     * @return Whether the given flags are a subset or equivalent with the underlying std::bitset.
+     */
+    auto contains_flags(std::bitset<64U> other) const -> bool;
+
+    /**
+     * @brief Extracts only the flags from the underlying entry and ignores all bits that contain the physical address.
+     *
+     * @return Extracted entry flags, without the physical address.
+     */
+    auto get_flags() const -> std::bitset<64U>;
+
+  private:
+    std::bitset<64U> flags;  ///< Underlying bitset used to read the flags from. Bits 9 - 11 and 52 - 62 can be
+                             ///< freely used for additional flags by the operating system.
+  };
+
+}  // namespace teachos::arch::memory::paging
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_PAGING_PAGE_ENTRY_HPP
diff --git a/arch/x86_64/pre/include/arch/memory/paging/page_table.hpp b/arch/x86_64/pre/include/arch/memory/paging/page_table.hpp
new file mode 100644
index 0000000..b972337
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/paging/page_table.hpp
@@ -0,0 +1,157 @@
+#ifndef TEACHOS_ARCH_X86_64_MEMORY_PAGING_PAGE_TABLE_HPP
+#define TEACHOS_ARCH_X86_64_MEMORY_PAGING_PAGE_TABLE_HPP
+
+#include "arch/exception_handling/assert.hpp"
+#include "arch/memory/allocator/concept.hpp"
+#include "arch/memory/paging/page_entry.hpp"
+
+namespace teachos::arch::memory::paging
+{
+  std::size_t constexpr PAGE_TABLE_ENTRY_COUNT = 512U;  ///< Default entry count of a page table in x86_84 is 512.
+
+  /**
+   * @brief Forward delcaration of the page_table, because it should only be accessible over the handle.
+   *
+   * @note The actual methods or constructor are not defined meaning they are not callable from outside. Instead the
+   * struct is only fully defined in the implementation (.cpp) file of the page table, and therefore the memthods are
+   * only accesible in that file.
+   */
+  struct page_table;
+
+  /**
+   * @brief Handle that ensures accessing the page table is safe because it adds additional checks to the next_table
+   * method and ensures it can only be called if the table level is not LEVEL1.
+   */
+  struct page_table_handle
+  {
+    /**
+     * @brief Level of the page table.
+     *
+     * Level 1 will not be able to call next_table anymore, because it would result in
+     * attempting to access memory that it should not.
+     */
+    enum level : uint8_t
+    {
+      LEVEL1,
+      LEVEL2,
+      LEVEL3,
+      LEVEL4
+    };
+
+    /**
+     * @brief Constructor.
+     *
+     * @param table Underlying page table the handle should point to.
+     * @param table_level Level the underlying page table is on, used to ensure safety.
+     */
+    page_table_handle(page_table * table, level table_level);
+
+    /**
+     * @brief Set every entry of the page to unused.
+     */
+    auto zero_entries() -> void;
+
+    /**
+     * @brief Checks if all entries of this page are unused.
+     */
+    auto is_empty() const -> bool;
+
+    /**
+     * @brief Get the current table level.
+     *
+     * @return Current table level.
+     */
+    auto get_level() const -> level;
+
+    /**
+     * @brief Returns the next page table level from the given page table index. Meaning we
+     * use an index into a Level 4 page table to get the according Level 3 page table.
+     *
+     * @note If this method is called with a Level 1 page table it will instead assert and halt execution, because there
+     * is no furthere page table and mangeling up and returning the physical address would cause hard to debug issues.
+     *
+     * @param table_index Index of this page table in the page table one level lower.
+     */
+    auto next_table(std::size_t table_index) const -> std::optional<page_table_handle>;
+
+    /**
+     * @brief Call next_table and then checks if the table already exists, if it does not it will use the given
+     * allocator to get the next free frame and set the entry to that instead.
+     *
+     * @param allocator Reference to an allocator following the FrameAllocator concept, which is used to allocate
+     * entries when a new page table is required.
+     * @param table_index Index of this page table in the page table one level lower.
+     * @param flags A bitset of flags that configure the page table entry for this mapping.
+     */
+    template<allocator::FrameAllocator T>
+    auto next_table_or_create(T & allocator, std::size_t table_index, std::bitset<64U> flags) -> page_table_handle
+    {
+      auto next_handle = next_table(table_index);
+      // If the next table method failed then it means that the page level of the frame we want allocate has not yet
+      // been created itself. So we have to do that before we are able to allocate the wanted frame. This has to be done
+      // for every level, meaning we potenitally create a level 4, level 3 and level 2 page entry, each pointing to a
+      // page table one level below.
+      if (!next_handle.has_value())
+      {
+        auto const allocated_frame = allocator.allocate_frame();
+        exception_handling::assert(allocated_frame.has_value(), "[Page mapper] Unable to allocate frame");
+        this->operator[](table_index).set_entry(allocated_frame.value(), entry::PRESENT | entry::WRITABLE);
+        // There should now be an entry at the previously not existent index, therefore we can simply access it again.
+        next_handle = next_table(table_index);
+        exception_handling::assert(next_handle.has_value(), "[Page mapper] Unable to create new entry into page table");
+        next_handle.value().zero_entries();
+      }
+
+      // Check if the now created or previously created  level 4, level 3 or level 2 page entry is used by user
+      // accessible code. If it is that page entry needs to be user accesible as well.
+      entry entry{flags.to_ulong()};
+      if (entry.contains_flags(entry::USER_ACCESSIBLE))
+      {
+        this->operator[](table_index).set_user_accessible();
+      }
+      return next_handle.value();
+    }
+
+    /**
+     * @brief Index operator overload to access specific mutable entry directy.
+     *
+     * @param index Index of the entry we want to access and only read.
+     * @return Entry at the given table index.
+     */
+    auto operator[](std::size_t index) -> entry &;
+
+    /**
+     * @brief Index operator overload to access specific immutable entry directy.
+     *
+     * @param index Index of the entry we want to access and read or write.
+     * @return Entry at the given table index.
+     */
+    auto operator[](std::size_t index) const -> entry const &;
+
+    /**
+     * @brief Pre decrement operator on the page table level enum, is defined so we can use it as a replacement
+     * for an int index in a range based for loop.
+     *
+     * @note Will halt execution if called with page_table_handle::LEVEL1, because there is no level below. Has to be
+     * defined as either a friend function or inline header method, because we define an operator of another type. In
+     * this instance friend function was choosen, because the struct itself also requires the operator, but declaring
+     * before the struct is not possible, because the enum is in the struct. This is inpossible because the struct
+     * requires the operator declared before itself to work, and the operator requires the struct declared before itself
+     * to work. Furthermore this allows the defintion of the method to be done in the cpp, avoiding includes in the
+     * header file.
+     *
+     * @param value Value we want to decrement on
+     * @return New level value decrement by one, meaning the level is also decrement by one Level4 --> Level3, ...
+     */
+    friend auto operator--(level & value) -> level &;
+
+  private:
+    page_table * table;  ///< Handle to underlying page table, can never be null (invariant ensured by
+                         ///< constructor)
+    level table_level;   ///< Level page table is currently on, depends on how often next_level was
+                         ///< called successfuly.
+  };
+
+}  // namespace teachos::arch::memory::paging
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_PAGING_PAGE_TABLE_HPP
diff --git a/arch/x86_64/pre/include/arch/memory/paging/temporary_page.hpp b/arch/x86_64/pre/include/arch/memory/paging/temporary_page.hpp
new file mode 100644
index 0000000..d0d7781
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/paging/temporary_page.hpp
@@ -0,0 +1,64 @@
+#ifndef TEACHOS_ARCH_X86_64_MEMORY_PAGING_TEMPORARY_PAGE_HPP
+#define TEACHOS_ARCH_X86_64_MEMORY_PAGING_TEMPORARY_PAGE_HPP
+
+#include "arch/memory/allocator/physical_frame.hpp"
+#include "arch/memory/allocator/tiny_frame_allocator.hpp"
+#include "arch/memory/paging/active_page_table.hpp"
+#include "arch/memory/paging/virtual_page.hpp"
+
+namespace teachos::arch::memory::paging
+{
+  /**
+   * @brief A temporary page used to remap the kernel.
+   */
+  struct temporary_page
+  {
+    /**
+     * @brief Construct a new temporary page object.
+     *
+     * @tparam Type constraint of the allocator, being that is follows the given concept and contains an allocate and
+     * deallocate method.
+     * @param page Page to turn into temporary page.
+     * @param allocator Frame allocator used to fill page.
+     */
+    template<allocator::FrameAllocator T>
+    temporary_page(virtual_page page, T & allocator)
+        : page{page}
+        , allocator{allocator}
+    {
+      // Nothing to do
+    }
+
+    /**
+     * @brief Unmap the current page.
+     *
+     * @param active_table The current active page table.
+     */
+    auto unmap_page(active_page_table & active_table) -> void;
+
+    /**
+     * @brief Map the temporary page to a frame.
+     *
+     * @param frame The frame to which the page is mapped.
+     * @param active_table The current active page table.
+     * @return level1 page table handle containing the mapped page.
+     */
+    auto map_table_frame(allocator::physical_frame frame, active_page_table & active_table) -> page_table_handle;
+
+  private:
+    /**
+     * @brief Map the temporary page to a frame.
+     *
+     * @param frame The frame to which the page is mapped.
+     * @param active_table The current active page table.
+     * @return The virtual address of the page.
+     */
+    auto map_to_frame(allocator::physical_frame frame, active_page_table & active_table) -> virtual_address;
+
+    virtual_page page;                          ///< Underlying virtual page we want to temporarily map.
+    allocator::tiny_frame_allocator allocator;  ///< Allocator that should be used to map the temporary page.
+  };
+
+}  // namespace teachos::arch::memory::paging
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_PAGING_TEMPORARY_PAGE_HPP
\ No newline at end of file
diff --git a/arch/x86_64/pre/include/arch/memory/paging/virtual_page.hpp b/arch/x86_64/pre/include/arch/memory/paging/virtual_page.hpp
new file mode 100644
index 0000000..a6c8c39
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/memory/paging/virtual_page.hpp
@@ -0,0 +1,91 @@
+#ifndef TEACHOS_ARCH_X86_64_MEMORY_PAGING_VIRTUAL_PAGE_HPP
+#define TEACHOS_ARCH_X86_64_MEMORY_PAGING_VIRTUAL_PAGE_HPP
+
+#include "arch/memory/allocator/physical_frame.hpp"
+#include "arch/memory/paging/page_table.hpp"
+
+#include <compare>
+#include <cstdint>
+#include <optional>
+
+namespace teachos::arch::memory::paging
+{
+  using virtual_address = std::size_t;
+
+  /**
+   * @brief Virtual page entry contained in P1 page tables
+   */
+  struct virtual_page
+  {
+    /**
+     * @brief Defaulted constructor.
+     */
+    constexpr virtual_page() = default;
+
+    /**
+     * @brief Constructor.
+     *
+     * @param page_number Index number of the current virtual page, used to distinguish it from other pages.
+     */
+    explicit constexpr virtual_page(std::size_t page_number)
+        : page_number(page_number)
+    {
+      // Nothing to do
+    }
+
+    /**
+     * @brief Returns the virtual page the given address is contained in.
+     *
+     * @param address Virtual address we want to get the corresponding virtual page for.
+     * @return Frame the given address is contained in.
+     */
+    auto static containing_address(virtual_address address) -> virtual_page;
+
+    /**
+     * @brief Evaluates the start address of the virtual page.
+     *
+     * @return Start address of the virtual page.
+     */
+    auto start_address() const -> virtual_address;
+
+    /**
+     * @brief Calculates the index into the page table with the given level, which leads to this virtual page.
+     *
+     * @param level Level of the page table we want to calculate the index for.
+     * @return Index into the page table with the given level.
+     */
+    auto get_level_index(page_table_handle::level level) const -> size_t;
+
+    /**
+     * @brief Post increment operator. Returns a copy of the value.
+     *
+     * @return Copy of the incremented underlying page number.
+     */
+    auto operator++(int) -> virtual_page;
+
+    /**
+     * @brief Pre increment operator. Returns a reference to the changed value.
+     *
+     * @return Reference to the incremented underlying page number.
+     */
+    auto operator++() -> virtual_page &;
+
+    /**
+     * @brief Defaulted equals operator.
+     */
+    auto operator==(const virtual_page & other) const -> bool = default;
+
+    /**
+     * @brief Defaulted three-way comparsion operator.
+     */
+    auto operator<=>(const virtual_page & other) const -> std::partial_ordering = default;
+
+    std::size_t page_number =
+        {};  ///< Index number of the current virtual page, used to distinguish it from other pages.
+  };
+
+  using page_container = stl::container<stl::forward_value_iterator<virtual_page>>;
+
+}  // namespace teachos::arch::memory::paging
+
+#endif  // TEACHOS_ARCH_X86_64_MEMORY_PAGING_VIRTUAL_PAGE_HPP
diff --git a/arch/x86_64/pre/include/arch/user/main.hpp b/arch/x86_64/pre/include/arch/user/main.hpp
new file mode 100644
index 0000000..c168a1f
--- /dev/null
+++ b/arch/x86_64/pre/include/arch/user/main.hpp
@@ -0,0 +1,16 @@
+#ifndef TEACHOS_ARCH_X86_64_USER_MAIN_HPP
+#define TEACHOS_ARCH_X86_64_USER_MAIN_HPP
+
+namespace teachos::arch::user
+{
+  /**
+   * @brief User Main method. If this method finishes there is no code left to run and the whole OS will shut down.
+   * Additionally this main method is executed at Ring 3 and accessing CPU Registers or Kernel level functionality can
+   * only be done over syscalls and not directly anymore.
+   */
+  [[gnu::section(".user_text")]]
+  auto main() -> void;
+
+}  // namespace teachos::arch::user
+
+#endif  // TEACHOS_ARCH_X86_64_USER_MAIN_HPP