avionic design with actual uboot and tooling

submodule of avionic design uboot bootloader and with included tools to
get you started , read readme.md and readme-tk1-loader.md

u-boot/post/cpu/mpc8xx/watchdog.c

@@ -0,0 +1,59 @@
+/*
+ * (C) Copyright 2002
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+
+/*
+ * Watchdog test
+ *
+ * The test verifies the watchdog timer operation.
+ * On the first iteration, the test routine disables interrupts and
+ * makes a 10-second delay. If the system does not reboot during this delay,
+ * the watchdog timer is not operational and the test fails. If the system
+ * reboots, on the second iteration the test routine reports a success.
+ */
+
+#include <post.h>
+#include <watchdog.h>
+
+#if CONFIG_POST & CONFIG_SYS_POST_WATCHDOG
+
+static ulong gettbl (void)
+{
+	ulong r;
+
+  asm ("mftbl %0":"=r" (r));
+
+	return r;
+}
+
+int watchdog_post_test (int flags)
+{
+	if (flags & POST_REBOOT) {
+		/* Test passed */
+
+		return 0;
+	} else {
+		/* 10-second delay */
+		int ints = disable_interrupts ();
+		ulong base = gettbl ();
+		ulong clk = get_tbclk ();
+
+		while ((gettbl () - base) / 10 < clk);
+
+		if (ints)
+			enable_interrupts ();
+
+		/*
+		 * If we have reached this point, the watchdog timer
+		 * does not work
+		 */
+		return -1;
+	}
+}
+
+#endif /* CONFIG_POST & CONFIG_SYS_POST_WATCHDOG */