Great Reorganisation, modify structure and makefile

1 files changed, 34 insertions, 0 deletions

diff --git a/src/arm/PL0/PL0_test.c b/src/arm/PL0/PL0_test.c
new file mode 100644
index 0000000..0bfebc7
--- /dev/null
+++ b/src/arm/PL0/PL0_test.c
@@ -0,0 +1,34 @@
+#include "PL0_utils.h"
+
+// entry point - must remain the only function in the file!
+void PL0_main(void)
+{
+  // If loading program to userspace and handling of svc are
+  // implemented correctly, this shall get printed
+  puts("Hello userspace! Type 'f' if you want me to try accessing "
+       "kernel memory!");
+
+  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);
+	}
+    }
+}