test,uart: preset some keys and them generate random keys

* now we can control the characters in PAL to trigger a battle

src/test/csrc/uart.cpp

@@ -14,38 +14,40 @@ static void uart_enqueue(char ch) {
   }
 }
 
-// generate a random key every 1s for pal
-static int rand_key(void) {
+static int uart_dequeue(void) {
+  int k = 0;
+  if (f != r) {
+    k = queue[f];
+    f = (f + 1) % QUEUE_SIZE;
+  } else {
+    // generate a random key every 1s for pal
+    k = "uiojkl"[rand()% 6];
+  }
+  return k;
+}
+
+int uart_getc(void) {
   uint32_t uptime(void);
   static uint32_t lasttime = 0;
   uint32_t now = uptime();
 
-  if (now - lasttime > 1000) {
+  if (now - lasttime > 30000) {
     lasttime = now;
-    return "uiojkl"[rand()% 6];
+    return uart_dequeue();
   } else {
     return 0;
   }
 }
 
-int uart_getc(void) {
-  int k = 0;
-  if (f != r) {
-    k = queue[f];
-    f = (f + 1) % QUEUE_SIZE;
-  } else {
-    k = rand_key();
-  }
-  return k;
-}
-
 void uart_putc(char c) {
   eprintf("%c", c);
 }
 
 static void preset_input() {
   char rtthread_cmd[128] = "memtrace\n";
-  char init_cmd[128] = "2";     // choose PAL
+  char init_cmd[128] = "2" // choose PAL
+    "jjjjjjjkkkkkk" // walk to enemy
+    ;
   char *buf = init_cmd;
   int i;
   for (i = 0; i < strlen(buf); i ++) {