Halt draft

user/halt.c

@@ -0,0 +1,9 @@
+#include "user.h"
+
+/** Stops the machine */
+int
+main(int argc, char *argv[])
+{
+  halt();
+  return 0;
+}

user/user.h

@@ -74,6 +74,9 @@ int uptime(void);
 /** trace */
 int trace(int);
 
+/** halt */
+void halt(void);
+
 /**
  * Library functions (ulib.c)
  */

user/usys.pl

@@ -14,7 +14,7 @@ sub entry {
     print " ecall\n";
     print " ret\n";
 }
-	
+
 entry("fork");
 entry("exit");
 entry("wait");
@@ -37,3 +37,4 @@ entry("sbrk");
 entry("sleep");
 entry("uptime");
 entry("trace");
+entry("halt");