Add cause number check in test kernel

test-kernel/src/main.rs

@@ -7,7 +7,7 @@
 mod console;
 mod sbi;
 
-use riscv::register::{sepc, stvec::{self, TrapMode}};
+use riscv::register::{sepc, stvec::{self, TrapMode}, scause::{self, Trap, Exception}};
 
 pub extern "C" fn rust_main(hartid: usize, dtb_pa: usize) -> ! {
     println!("<< Test-kernel: Hart id = {}, DTB physical address = {:#x}", hartid, dtb_pa);
@@ -45,6 +45,12 @@ fn test_sbi_ins_emulation() {
 }
 
 pub extern "C" fn rust_trap_exception() {
+    let cause = scause::read().cause();
+    println!("<< Test-kernel: Value of scause: {:?}", cause);
+    if cause != Trap::Exception(Exception::IllegalInstruction) {
+        println!("!! Test-kernel: Wrong cause associated to illegal instruction");
+        sbi::shutdown()
+    }
     println!("<< Test-kernel: Illegal exception delegate success");
     sepc::write(sepc::read().wrapping_add(4));
 }