Draft: lab 3 irq wtf

kernel/include/utils.h

@@ -43,8 +43,14 @@ void exit(int);
     : [a] "=r" (ret) \
   )
 
-#define W_SYSREG(val, reg) \
+#define W_SYSREG(reg, val) \
   asm volatile( \
     "msr " #reg ", %[a]" \
-    : [a] "r" (val) \
+    :: [a] "r" (val) \
+  )
+
+#define R_REG(ret, reg) \
+  asm volatile( \
+    "mov %[a], " #reg \
+    : [a] "=r" (ret) \
   )