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/arch/nds32/cpu/n1213/ag101/watchdog.S

@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2011 Andes Technology Corporation
+ * Macpaul Lin, Andes Technology Corporation <macpaul@andestech.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <asm/arch-ag101/ag101.h>
+#include <linux/linkage.h>
+
+.text
+
+#ifndef CONFIG_SKIP_TRUNOFF_WATCHDOG
+ENTRY(turnoff_watchdog)
+
+#define WD_CR		0xC
+#define WD_ENABLE	0x1
+
+	! Turn off the watchdog, according to Faraday FTWDT010 spec
+	li 	$p0, (CONFIG_FTWDT010_BASE+WD_CR)	! Get the addr of WD CR
+	lwi	$p1, [$p0]				! Get the config of WD
+	andi	$p1, $p1, 0x1f				! Wipe out useless bits
+	li	$r0, ~WD_ENABLE
+	and	$p1, $p1, $r0				! Set WD disable
+	sw	$p1, [$p0]				! Write back to WD CR
+
+	! Disable Interrupts by clear GIE in $PSW reg
+	setgie.d
+
+	ret
+
+ENDPROC(turnoff_watchdog)
+#endif