add debug handler for x86_64

Signed-off-by: Godones <chenlinfeng25@outlook.com>

Author: Godones

src/trap.rs

@@ -19,6 +19,10 @@ pub static PAGE_FAULT: [fn(VirtAddr, PageFaultFlags) -> bool];
 #[def_trap_handler]
 pub static BREAK_HANDLER: [fn(&mut TrapFrame) -> bool];
 
+/// A slice of debug handler functions.
+#[def_trap_handler]
+pub static DEBUG_HANDLER: [fn(&mut TrapFrame) -> bool];
+
 #[allow(unused_macros)]
 macro_rules! handle_trap {
     ($trap:ident, $($args:tt)*) => {{

src/x86_64/trap.rs

@@ -46,10 +46,18 @@ fn handle_breakpoint(tf: &mut TrapFrame) {
     }
 }
 
+fn handle_debug(tf: &mut TrapFrame) {
+    debug!("#DB @ {:#x} ", tf.rip);
+    if core::hint::likely(handle_trap!(DEBUG_HANDLER, tf)) {
+        return;
+    }
+}
+
 #[unsafe(no_mangle)]
 fn x86_trap_handler(tf: &mut TrapFrame) {
     match tf.vector as u8 {
         PAGE_FAULT_VECTOR => handle_page_fault(tf),
+        DEBUG_VECTOR => handle_debug(tf),
         BREAKPOINT_VECTOR => handle_breakpoint(tf),
         GENERAL_PROTECTION_FAULT_VECTOR => {
             panic!(