WIP syscall

1 files changed, 21 insertions, 1 deletions

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 6075770..7afd87d 100644
--- a/arch/x86_64/src/interrupt_handling/generic_interrupt_handler.cpp
+++ b/arch/x86_64/src/interrupt_handling/generic_interrupt_handler.cpp
@@ -15,7 +15,27 @@ namespace teachos::arch::interrupt_handling
   [[gnu::interrupt]] [[gnu::section(".interrupt_text")]]
   auto syscall_interrupt_handler(interrupt_frame * frame) -> void
   {
+    // RDI, RSI, RDX, RCX, R8, R9
+    // RDI -> SYSCALL number
+    // Others are arguments
+
+    // TODO: The registers are not available here. We need to set them up on the stack
+    // and access them via argument.
+
+    uint64_t syscall_number{};
+    asm volatile("mov %%rdi, %0" : "=r"(syscall_number));
+
+    // Handle system call based on the number
+    switch (syscall_number)
+    {
+      case 1:
+        video::vga::text::write("SYSCALL 1.", video::vga::text::common_attributes::green_on_black);
+        break;
+      default:
+        // Handle unknown syscall
+        break;
+    }
+
     (void)frame;
-    video::vga::text::write("A SYSCALL interrupt occurred.", video::vga::text::common_attributes::green_on_black);
   }
 }  // namespace teachos::arch::interrupt_handling