Implement idtr structure and document possible flags.

8 files changed, 139 insertions, 67 deletions

diff --git a/arch/x86_64/src/context_switching/interrupt_descriptor_table/gate_descriptor.cpp b/arch/x86_64/src/context_switching/interrupt_descriptor_table/gate_descriptor.cpp
index 4f18197..28f289c 100644
--- a/arch/x86_64/src/context_switching/interrupt_descriptor_table/gate_descriptor.cpp
+++ b/arch/x86_64/src/context_switching/interrupt_descriptor_table/gate_descriptor.cpp
@@ -2,4 +2,23 @@
 
 namespace teachos::arch::context_switching::interrupt_descriptor_table
 {
+  gate_descriptor::gate_descriptor(uint128_t flags)
+      : _offset_1(flags)
+      , _selector(flags >> 19U, flags >> 16U)
+      , _ist(flags >> 32U)
+      , _flags(flags >> 40U)
+      , _offset_2(flags >> 48U)
+  {
+    // Nothing to do.
+  }
+
+  gate_descriptor::gate_descriptor(segment_selector selector, ist_offset ist, idt_flags flags, uint64_t offset)
+      : _offset_1(offset)
+      , _selector(selector)
+      , _ist(ist)
+      , _flags(flags)
+      , _offset_2(offset >> 16U)
+  {
+    // Nothing to do.
+  }
 }  // namespace teachos::arch::context_switching::interrupt_descriptor_table
diff --git a/arch/x86_64/src/context_switching/interrupt_descriptor_table/idt_flags.cpp b/arch/x86_64/src/context_switching/interrupt_descriptor_table/idt_flags.cpp
new file mode 100644
index 0000000..e7379ef
--- /dev/null
+++ b/arch/x86_64/src/context_switching/interrupt_descriptor_table/idt_flags.cpp
@@ -0,0 +1,15 @@
+#include "arch/context_switching/interrupt_descriptor_table/idt_flags.hpp"
+
+namespace teachos::arch::context_switching::interrupt_descriptor_table
+{
+  idt_flags::idt_flags(uint8_t flags)
+      : _flags(flags)
+  {
+    // Nothing to do.
+  }
+
+  auto idt_flags::contains_flags(std::bitset<8U> other) const -> bool
+  {
+    return (std::bitset<8U>{_flags} & other) == other;
+  }
+}  // namespace teachos::arch::context_switching::interrupt_descriptor_table
diff --git a/arch/x86_64/src/context_switching/interrupt_descriptor_table/interrupt_descriptor_table.cpp b/arch/x86_64/src/context_switching/interrupt_descriptor_table/interrupt_descriptor_table.cpp
index 619a695..7346248 100644
--- a/arch/x86_64/src/context_switching/interrupt_descriptor_table/interrupt_descriptor_table.cpp
+++ b/arch/x86_64/src/context_switching/interrupt_descriptor_table/interrupt_descriptor_table.cpp
@@ -1,10 +1,28 @@
 #include "arch/context_switching/interrupt_descriptor_table/interrupt_descriptor_table.hpp"
 
+#include "arch/exception_handling/assert.hpp"
+#include "arch/kernel/cpu/idtr.hpp"
+
 namespace teachos::arch::context_switching::interrupt_descriptor_table
 {
-  auto initialize_interrupt_descriptor_table() -> void
+  namespace
   {
-    // DO NOT
-  }
+    auto create_interrupt_descriptor_table() -> interrupt_descriptor_table { return interrupt_descriptor_table{}; }
+  }  // namespace
+
+  auto initialize_interrupt_descriptor_table() -> interrupt_descriptor_table &
+  {
+    // Interrupt Descriptor Table needs to be kept alive
+    static auto idt = create_interrupt_descriptor_table();
 
+    interrupt_descriptor_table_pointer idt_pointer{static_cast<uint16_t>(idt.size() - 1), &idt};
+    kernel::cpu::load_interrupt_descriptor_table(idt_pointer);
+
+    auto const stored_gdt_pointer = kernel::cpu::store_interrupt_descriptor_table();
+    arch::exception_handling::assert(
+        idt_pointer == stored_gdt_pointer,
+        "[Interrupt Descriptor Table] Loaded IDTR value is not the same as the stored value.");
+
+    return idt;
+  }
 }  // namespace teachos::arch::context_switching::interrupt_descriptor_table
diff --git a/arch/x86_64/src/context_switching/interrupt_descriptor_table/ist_offset.cpp b/arch/x86_64/src/context_switching/interrupt_descriptor_table/ist_offset.cpp
new file mode 100644
index 0000000..a70e75d
--- /dev/null
+++ b/arch/x86_64/src/context_switching/interrupt_descriptor_table/ist_offset.cpp
@@ -0,0 +1,10 @@
+#include "arch/context_switching/interrupt_descriptor_table/ist_offset.hpp"
+
+namespace teachos::arch::context_switching::interrupt_descriptor_table
+{
+  ist_offset::ist_offset(uint8_t index)
+      : _ist(index)
+  {
+    // Nothing to do.
+  }
+}  // namespace teachos::arch::context_switching::interrupt_descriptor_table
diff --git a/arch/x86_64/src/context_switching/interrupt_descriptor_table/segment_selector.cpp b/arch/x86_64/src/context_switching/interrupt_descriptor_table/segment_selector.cpp
new file mode 100644
index 0000000..494e50f
--- /dev/null
+++ b/arch/x86_64/src/context_switching/interrupt_descriptor_table/segment_selector.cpp
@@ -0,0 +1,16 @@
+#include "arch/context_switching/interrupt_descriptor_table/segment_selector.hpp"
+
+namespace teachos::arch::context_switching::interrupt_descriptor_table
+{
+  segment_selector::segment_selector(uint16_t index, uint8_t flags)
+      : _flags(flags)
+      , _index(index)
+  {
+    // Nothing to do.
+  }
+
+  auto segment_selector::contains_flags(std::bitset<3U> other) const -> bool
+  {
+    return (std::bitset<3U>{_flags} & other) == other;
+  }
+}  // namespace teachos::arch::context_switching::interrupt_descriptor_table
diff --git a/arch/x86_64/src/context_switching/main.cpp b/arch/x86_64/src/context_switching/main.cpp
index b682e79..95a25e0 100644
--- a/arch/x86_64/src/context_switching/main.cpp
+++ b/arch/x86_64/src/context_switching/main.cpp
@@ -11,10 +11,7 @@ namespace teachos::arch::context_switching
   auto initialize_descriptor_tables() -> descriptor_tables
   {
     decltype(auto) global_descriptor_table = segment_descriptor_table::initialize_global_descriptor_table();
-
-    // TODO: Replace random construction with return value of initialization.
-    interrupt_descriptor_table::interrupt_descriptor_table idt{};
-    interrupt_descriptor_table::initialize_interrupt_descriptor_table();
+    decltype(auto) interrupt_descriptor_table = interrupt_descriptor_table::initialize_interrupt_descriptor_table();
 
     kernel::cpu::jmp((uint64_t)&global_descriptor_table.at(1), boot::segment_register_reload_pointer);
 
@@ -30,7 +27,7 @@ namespace teachos::arch::context_switching
 
     kernel::cpu::set_interrupt_flag();
 
-    descriptor_tables tables = {global_descriptor_table, idt};
+    descriptor_tables tables = {global_descriptor_table, interrupt_descriptor_table};
     return tables;
   }
 }  // namespace teachos::arch::context_switching
diff --git a/arch/x86_64/src/context_switching/segment_descriptor_table/global_descriptor_table.cpp b/arch/x86_64/src/context_switching/segment_descriptor_table/global_descriptor_table.cpp
index 1bbd24f..69cce19 100644
--- a/arch/x86_64/src/context_switching/segment_descriptor_table/global_descriptor_table.cpp
+++ b/arch/x86_64/src/context_switching/segment_descriptor_table/global_descriptor_table.cpp
@@ -9,69 +9,66 @@
 
 namespace teachos::arch::context_switching::segment_descriptor_table
 {
-  auto create_segment_descriptor(segment_descriptor_type segment_descriptor_type, access_level access_level)
-      -> segment_descriptor
+  namespace
   {
-    uint8_t access_level_bitset = access_byte::PRESENT | access_byte::CODE_OR_DATA_SEGMENT;
-    if (access_level == access_level::KERNEL)
-    {
-      access_level_bitset |= access_byte::ACCESS_LEVEL_KERNEL;
-    }
-    else if (access_level == access_level::USER)
-    {
-      access_level_bitset |= access_byte::ACCESS_LEVEL_USER;
-    }
 
-    uint8_t gdt_flags_bitset = gdt_flags::GRANULARITY;
-    if (segment_descriptor_type == segment_descriptor_type::CODE_SEGMENT)
+    auto create_segment_descriptor(segment_descriptor_type segment_descriptor_type, access_byte access_level)
+        -> segment_descriptor
     {
-      gdt_flags_bitset |= gdt_flags::LENGTH;
-      access_level_bitset |= access_byte::CODE_SEGMENT | access_byte::READABLE;
+      uint8_t access_level_bits =
+          access_byte::PRESENT | access_byte::CODE_OR_DATA_SEGMENT | *reinterpret_cast<uint8_t *>(&access_level);
+      uint8_t gdt_flags_bits = gdt_flags::GRANULARITY;
+      if (segment_descriptor_type == segment_descriptor_type::CODE_SEGMENT)
+      {
+        gdt_flags_bits |= gdt_flags::LENGTH;
+        access_level_bits |= access_byte::CODE_SEGMENT | access_byte::READABLE;
+      }
+      else if (segment_descriptor_type == segment_descriptor_type::DATA_SEGMENT)
+      {
+        gdt_flags_bits |= gdt_flags::UPPER_BOUND;
+        access_level_bits |= access_byte::WRITABLE;
+      }
+
+      uint64_t const base = 0x0;
+      std::bitset<20U> const limit{0xFFFFF};
+      access_byte const access_byte{access_level_bits};
+      gdt_flags const gdt_flags{gdt_flags_bits, limit};
+      segment_descriptor const segment_descriptor{access_byte, gdt_flags, base, limit};
+      return segment_descriptor;
     }
-    else if (segment_descriptor_type == segment_descriptor_type::DATA_SEGMENT)
+
+    auto create_task_state_segment_descriptor(task_state_segment * tss) -> segment_descriptor
     {
-      gdt_flags_bitset |= gdt_flags::UPPER_BOUND;
-      access_level_bitset |= access_byte::WRITABLE;
+      constexpr uint64_t TSS_LIMIT = sizeof(task_state_segment) - 1;
+      access_byte const tss_access_byte{access_byte::PRESENT | access_byte::DESCRIPTOR_LEVEL_KERNEL |
+                                        access_byte::TASK_STATE_SEGMENT_AVAILABLE};
+      gdt_flags const tss_gdt_flags{0U, TSS_LIMIT};
+      segment_descriptor const tss_descriptor{tss_access_byte, tss_gdt_flags, reinterpret_cast<uint64_t>(tss),
+                                              TSS_LIMIT};
+      return tss_descriptor;
     }
 
-    uint64_t const base = 0x0;
-    std::bitset<20U> const limit{0xFFFFF};
-    access_byte const access_byte{access_level_bitset};
-    gdt_flags const gdt_flags{gdt_flags_bitset, limit};
-    segment_descriptor const segment_descriptor{access_byte, gdt_flags, base, limit};
-    return segment_descriptor;
-  }
-
-  auto create_global_descriptor_table() -> global_descriptor_table
-  {
-    segment_descriptor const null_segment{0};
-    segment_descriptor const kernel_code_segment =
-        create_segment_descriptor(segment_descriptor_type::CODE_SEGMENT, access_level::KERNEL);
-    segment_descriptor const kernel_data_segment =
-        create_segment_descriptor(segment_descriptor_type::DATA_SEGMENT, access_level::KERNEL);
-    segment_descriptor const user_code_segment =
-        create_segment_descriptor(segment_descriptor_type::CODE_SEGMENT, access_level::USER);
-    segment_descriptor const user_data_segment =
-        create_segment_descriptor(segment_descriptor_type::DATA_SEGMENT, access_level::USER);
-
-    // Task State Segment needs to be kept alive
-    static auto tss = new task_state_segment();
-    segment_descriptor const tss_descriptor = create_task_state_segment_descriptor(tss);
+    auto create_global_descriptor_table() -> global_descriptor_table
+    {
+      segment_descriptor const null_segment{0};
+      segment_descriptor const kernel_code_segment =
+          create_segment_descriptor(segment_descriptor_type::CODE_SEGMENT, access_byte::DESCRIPTOR_LEVEL_KERNEL);
+      segment_descriptor const kernel_data_segment =
+          create_segment_descriptor(segment_descriptor_type::DATA_SEGMENT, access_byte::DESCRIPTOR_LEVEL_KERNEL);
+      segment_descriptor const user_code_segment =
+          create_segment_descriptor(segment_descriptor_type::CODE_SEGMENT, access_byte::DESCRIPTOR_LEVEL_USER);
+      segment_descriptor const user_data_segment =
+          create_segment_descriptor(segment_descriptor_type::DATA_SEGMENT, access_byte::DESCRIPTOR_LEVEL_USER);
 
-    global_descriptor_table const global_descriptor_table{null_segment,      kernel_code_segment, kernel_data_segment,
-                                                          user_code_segment, user_data_segment,   tss_descriptor};
-    return global_descriptor_table;
-  }
+      // Task State Segment needs to be kept alive
+      static auto tss = new task_state_segment();
+      segment_descriptor const tss_descriptor = create_task_state_segment_descriptor(tss);
 
-  auto create_task_state_segment_descriptor(task_state_segment * tss) -> segment_descriptor
-  {
-    constexpr uint64_t TSS_LIMIT = sizeof(task_state_segment) - 1;
-    access_byte const tss_access_byte{access_byte::PRESENT | access_byte::ACCESS_LEVEL_KERNEL |
-                                      access_byte::TASK_STATE_SEGMENT_AVAILABLE};
-    gdt_flags const tss_gdt_flags{0U, TSS_LIMIT};
-    segment_descriptor const tss_descriptor{tss_access_byte, tss_gdt_flags, reinterpret_cast<uint64_t>(tss), TSS_LIMIT};
-    return tss_descriptor;
-  }
+      global_descriptor_table const global_descriptor_table{null_segment,      kernel_code_segment, kernel_data_segment,
+                                                            user_code_segment, user_data_segment,   tss_descriptor};
+      return global_descriptor_table;
+    }
+  }  // namespace
 
   auto initialize_global_descriptor_table() -> global_descriptor_table &
   {
diff --git a/arch/x86_64/src/context_switching/segment_descriptor_table/segment_descriptor.cpp b/arch/x86_64/src/context_switching/segment_descriptor_table/segment_descriptor.cpp
index 6d831a1..74f93b2 100644
--- a/arch/x86_64/src/context_switching/segment_descriptor_table/segment_descriptor.cpp
+++ b/arch/x86_64/src/context_switching/segment_descriptor_table/segment_descriptor.cpp
@@ -3,11 +3,11 @@
 namespace teachos::arch::context_switching::segment_descriptor_table
 {
   segment_descriptor::segment_descriptor(uint128_t flags)
-      : _limit_1(flags << 112U)
-      , _base_1((flags >> 16U) << 88U)
-      , _access((flags >> 40U) << 80U)
-      , _flag((flags >> 52U) << 72U, (flags >> 48U) << 72U)
-      , _base_2((flags >> 56U) << 32U)
+      : _limit_1(flags)
+      , _base_1(flags >> 16U)
+      , _access(flags >> 40U)
+      , _flag(flags >> 52U, flags >> 48U)
+      , _base_2(flags >> 56U)
   {
     // Nothing to do.
   }