print: add mutex for smp

kernel-src/sys/syscalls/print.c

@@ -1,14 +1,25 @@
 #include <kernel/syscalls.h>
 #include <printf.h>
 #include <arch/e9.h>
+#include <mutex.h>
 
 syscallret_t syscall_print(context_t *context, char *message) {
 	syscallret_t ret = {
 		.ret = 0,
 		.errno = 0
 	};
-	//printf("%s\n", message);
+
+	static mutex_t mutex;
+	static bool initialized = false;
+
+	if (initialized == false) {
+		MUTEX_INIT(&mutex);
+		initialized = true;
+	}
+
+	MUTEX_ACQUIRE(&mutex, false);
 	arch_e9_puts(message);
 	arch_e9_putc('\n');
+	MUTEX_RELEASE(&mutex);
 	return ret;
 }