GK SDK 源码库: XMIPCLinuxV100R005C00SPC030 (kernel/tools/open_source excluded)

source/bootloader/u-boot-2020.01/board/google/gru/gru.c

@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2018 Google
+ */
+
+#include <common.h>
+
+#ifdef CONFIG_SPL_BUILD
+/* provided to defeat compiler optimisation in board_init_f() */
+void gru_dummy_function(int i)
+{
+}
+
+int board_early_init_f(void)
+{
+# ifdef CONFIG_TARGET_CHROMEBOOK_BOB
+	int sum, i;
+
+	/*
+	 * Add a delay and ensure that the compiler does not optimise this out.
+	 * This is needed since the power rails tail a while to turn on, and
+	 * we get garbage serial output otherwise.
+	 */
+	sum = 0;
+	for (i = 0; i < 150000; i++)
+		sum += i;
+	gru_dummy_function(sum);
+#endif /* CONFIG_TARGET_CHROMEBOOK_BOB */
+
+	return 0;
+}
+#endif