1 files changed, 17 insertions, 12 deletions

diff --git a/PL0_test.c b/PL0_test.c
index ac74ad4..c6cbe18 100644
--- a/PL0_test.c
+++ b/PL0_test.c
@@ -5,25 +5,30 @@ void PL0_main(void)
 {
   // If loading program to userspace and handling of svc are
   // implemented correctly, this shall get printed
-  puts("Hello userspace!");
+  puts("Hello userspace! Type 'f' if you want me to try accessing "
+       "kernel memory!");
   
-  // if we're indeed in PL0, we should trigger the abort handler now,
-  // when trying to access memory we're not allowed to
-  puts("Attempting to meddle with kernel memory from userspace :d");
-  char first_kernel_byte[2];
-
-  first_kernel_byte[0] = *(char*) 0x0;
-  first_kernel_byte[1] = '\0';
-
-  puts(first_kernel_byte);
-    
   while (1)
     {
       char c = getchar();
       
       if (c == '\r')
 	putchar('\n');
-
+      
       putchar(c);
+      
+      if (c == 'f')
+	{
+	  // if we're indeed in PL0, we should trigger the abort
+	  // handler now, when trying to access memory we're not
+	  // allowed to
+	  puts("Attempting to read kernel memory from userspace :d");
+	  char first_kernel_byte[2];
+
+	  first_kernel_byte[0] = *(char*) 0x0;
+	  first_kernel_byte[1] = '\0';
+
+	  puts(first_kernel_byte);
+	}
     }
 }