Merge branch 'syscall_interrupt_handler' into feat_inital_context_switching

4 files changed, 30 insertions, 7 deletions

diff --git a/arch/x86_64/include/arch/interrupt_handling/generic_interrupt_handler.hpp b/arch/x86_64/include/arch/interrupt_handling/generic_interrupt_handler.hpp
index 6c1db12..309acbb 100644
--- a/arch/x86_64/include/arch/interrupt_handling/generic_interrupt_handler.hpp
+++ b/arch/x86_64/include/arch/interrupt_handling/generic_interrupt_handler.hpp
@@ -13,12 +13,12 @@ namespace teachos::arch::interrupt_handling
    */
   struct [[gnu::packed]] interrupt_frame
   {
-    uint64_t error_code;  ///< Error code pushed by some exceptions.
-    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.
+    // uint64_t error_code;  ///< Error code pushed by some exceptions.
+    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.
   };
 
   /**
@@ -29,6 +29,14 @@ namespace teachos::arch::interrupt_handling
   [[gnu::interrupt]]
   auto generic_interrupt_handler(struct interrupt_frame * frame) -> void;
 
+  /**
+   * @brief Interrupt handler function for syscalls (INT 0x80).
+   *
+   * @param frame Pointer to the interrupt frame containing CPU state.
+   */
+  [[gnu::interrupt]]
+  auto syscall_interrupt_handler(struct 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/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 80f01a8..c50ac1d 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
@@ -10,7 +10,7 @@ namespace teachos::arch::context_switching::interrupt_descriptor_table
   {
     /// @brief Amount of currently reserved interrupt indicies.
     /// See https://wiki.osdev.org/Interrupt_Descriptor_Table#IDT_items for more information.
-    constexpr uint8_t RESERVED_INTERRUPT_COUNT = 32U;
+    constexpr uint16_t RESERVED_INTERRUPT_COUNT = 256U;
 
     auto create_interrupt_descriptor_table() -> interrupt_descriptor_table
     {
@@ -26,6 +26,11 @@ namespace teachos::arch::context_switching::interrupt_descriptor_table
         interrupt_descriptor_table.at(i) = {selector, ist, flags, offset};
       }
 
+      interrupt_descriptor_table.at(0x80) = {
+          segment_selector{3U, segment_selector::REQUEST_LEVEL_USER}, ist_offset{0U},
+          idt_flags{idt_flags::DESCRIPTOR_LEVEL_USER | idt_flags::INTERRUPT_GATE | idt_flags::PRESENT},
+          uint64_t{reinterpret_cast<uint64_t>(interrupt_handling::syscall_interrupt_handler)}};
+
       return interrupt_descriptor_table;
     }
   }  // namespace
diff --git a/arch/x86_64/src/context_switching/main.cpp b/arch/x86_64/src/context_switching/main.cpp
index 486a09f..7be286a 100644
--- a/arch/x86_64/src/context_switching/main.cpp
+++ b/arch/x86_64/src/context_switching/main.cpp
@@ -51,6 +51,9 @@ namespace teachos::arch::context_switching
   auto user_mode_main() -> void
   {
     kernel::cpu::validate_segment_registers(USER_DATA_SEGMENT_SELECTOR, USER_CODE_SEGMENT_SELECTOR);
+
+    asm volatile("INT $0x80");
+
     video::vga::text::write("Successfully entered user mode!", video::vga::text::common_attributes::green_on_black);
   }
 
diff --git a/arch/x86_64/src/interrupt_handling/generic_interrupt_handler.cpp b/arch/x86_64/src/interrupt_handling/generic_interrupt_handler.cpp
index 4392b04..6075770 100644
--- a/arch/x86_64/src/interrupt_handling/generic_interrupt_handler.cpp
+++ b/arch/x86_64/src/interrupt_handling/generic_interrupt_handler.cpp
@@ -11,4 +11,11 @@ namespace teachos::arch::interrupt_handling
     (void)frame;
     video::vga::text::write("An Interrupt occurred.", video::vga::text::common_attributes::green_on_black);
   }
+
+  [[gnu::interrupt]] [[gnu::section(".interrupt_text")]]
+  auto syscall_interrupt_handler(interrupt_frame * frame) -> void
+  {
+    (void)frame;
+    video::vga::text::write("A SYSCALL interrupt occurred.", video::vga::text::common_attributes::green_on_black);
+  }
 }  // namespace teachos::arch::interrupt_handling