Implement argument_ptr () syscall for handling process arguments

init/init.c

@@ -9,23 +9,10 @@
 
 LOCAL volatile char letter = 'c';
 
-void app_proc1 (void) {
-  letter = 'b';
+void app_proc (void) {
+  char arg_letter = (char)(uintptr_t)argument_ptr ();
 
-  for (;;) {
-    mutex_lock (MUTEX);
-
-    for (int i = 0; i < 3; i++)
-      test (letter);
-
-    mutex_unlock (MUTEX);
-  }
-
-  process_quit ();
-}
-
-void app_proc2 (void) {
-  letter = 'd';
+  letter = arg_letter;
 
   for (;;) {
     mutex_lock (MUTEX);
@@ -44,8 +31,9 @@ void app_main (void) {
 
   letter = 'a';
 
-  process_spawn (&app_proc1);
-  process_spawn (&app_proc2);
+  process_spawn (&app_proc, (void*)'a');
+  process_spawn (&app_proc, (void*)'b');
+  process_spawn (&app_proc, (void*)'c');
 
   for (;;) {
     mutex_lock (MUTEX);