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/drivers/watchdog/imx_watchdog.c

@@ -0,0 +1,55 @@
+/*
+ * watchdog.c - driver for i.mx on-chip watchdog
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <watchdog.h>
+#include <asm/arch/imx-regs.h>
+#include <fsl_wdog.h>
+
+#ifdef CONFIG_IMX_WATCHDOG
+void hw_watchdog_reset(void)
+{
+	struct watchdog_regs *wdog = (struct watchdog_regs *)WDOG1_BASE_ADDR;
+
+	writew(0x5555, &wdog->wsr);
+	writew(0xaaaa, &wdog->wsr);
+}
+
+void hw_watchdog_init(void)
+{
+	struct watchdog_regs *wdog = (struct watchdog_regs *)WDOG1_BASE_ADDR;
+	u16 timeout;
+
+	/*
+	 * The timer watchdog can be set between
+	 * 0.5 and 128 Seconds. If not defined
+	 * in configuration file, sets 128 Seconds
+	 */
+#ifndef CONFIG_WATCHDOG_TIMEOUT_MSECS
+#define CONFIG_WATCHDOG_TIMEOUT_MSECS 128000
+#endif
+	timeout = (CONFIG_WATCHDOG_TIMEOUT_MSECS / 500) - 1;
+	writew(WCR_WDZST | WCR_WDBG | WCR_WDE | WCR_WDT | WCR_SRS |
+		SET_WCR_WT(timeout), &wdog->wcr);
+	hw_watchdog_reset();
+}
+#endif
+
+void reset_cpu(ulong addr)
+{
+	struct watchdog_regs *wdog = (struct watchdog_regs *)WDOG1_BASE_ADDR;
+
+	clrsetbits_le16(&wdog->wcr, WCR_WT_MSK, WCR_WDE);
+
+	writew(0x5555, &wdog->wsr);
+	writew(0xaaaa, &wdog->wsr);	/* load minimum 1/2 second timeout */
+	while (1) {
+		/*
+		 * spin for .5 seconds before reset
+		 */
+	}
+}