diff --git a/Cargo.toml b/Cargo.toml
index 440df504..ae26d14d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -24,6 +24,7 @@ log-panic = ["log-serial"]
 integration_tests = []
 coreboot = []
 efi-var = []
+debug = []
 
 [dependencies]
 bitflags = "2.2.1"
diff --git a/src/arch/aarch64/ram64.s b/src/arch/aarch64/ram64.s
index 93e28e63..0f6226f1 100644
--- a/src/arch/aarch64/ram64.s
+++ b/src/arch/aarch64/ram64.s
@@ -3,6 +3,7 @@
 
 .section .text.boot, "ax"
 .global ram64_start
+.global debug_point
 
 ram64_start:
   /*
@@ -26,6 +27,8 @@ ram64_start:
   .align 3
 
 jump_to_rust:
+  bl debug_point
+
   /* x0 typically points to device tree at entry */
   ldr x0, ={FDT_START}
 
@@ -34,4 +37,4 @@ jump_to_rust:
   mov sp, x30
 
   /* x0: pointer to device tree */
-  b rust64_start
\ No newline at end of file
+  b rust64_start
diff --git a/src/main.rs b/src/main.rs
index 53fb2dc2..fae986fd 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -27,6 +27,10 @@ use core::panic::PanicInfo;
 #[cfg(target_arch = "x86_64")]
 use x86_64::instructions::hlt;
 
+#[cfg(target_arch = "aarch64")]
+#[cfg(feature = "debug")]
+use core::arch::asm;
+
 #[macro_use]
 mod serial;
 
@@ -144,6 +148,19 @@ fn boot_from_device(device: &mut block::VirtioBlockDevice, info: &dyn bootinfo::
     };
 
     log!("Executable loaded");
+
+    // mark here as the end of firmware and put stub here
+    #[cfg(target_arch = "aarch64")]
+    #[cfg(feature = "debug")]
+    unsafe {
+        asm! {"
+            movz    x7, 0x0900, lsl 16
+            add     x7, x7, 0xf00
+            mov     x8, 0x02
+            str     w8, [x7]"
+        }
+    }
+
     efi::efi_exec(entry_addr, load_addr, size, info, &f, device);
     true
 }
@@ -165,6 +182,25 @@ pub extern "C" fn rust64_start(#[cfg(not(feature = "coreboot"))] pvh_info: &pvh:
     main(info)
 }
 
+#[cfg(target_arch = "aarch64")]
+#[cfg(feature = "debug")]
+#[no_mangle]
+pub extern "C" fn debug_point() {
+    unsafe {
+        asm! {"
+            movz    x7, 0x0900, lsl 16
+            add     x7, x7, 0xf00
+            mov     x8, 0x01
+            str     w8, [x7]"
+        }
+    }
+}
+
+#[cfg(target_arch = "aarch64")]
+#[cfg(not(feature = "debug"))]
+#[no_mangle]
+pub extern "C" fn debug_point() {}
+
 #[cfg(target_arch = "aarch64")]
 #[no_mangle]
 pub extern "C" fn rust64_start(x0: *const u8) -> ! {