Fix: on board

bootloader/main.c

@@ -14,7 +14,7 @@ void main(void *dtb)
   uart_puts("waiting for kernel to be sent ..." ENDL);
 
   union {
-    int size;
+    int32_t size;
     uint8_t buf[4];
   } kernel_header;
   kernel_header.size = 0;