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/arm/cpu/armv7m/Makefile

@@ -0,0 +1,9 @@
+#
+# (C) Copyright 2000-2006
+# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+extra-y := start.o
+obj-y += cpu.o

u-boot/arch/arm/cpu/armv7m/config.mk

@@ -0,0 +1,8 @@
+#
+# (C) Copyright 2015
+# Kamil Lulko, <kamil.lulko@gmail.com>
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+PLATFORM_CPPFLAGS += -march=armv7-m -mthumb

u-boot/arch/arm/cpu/armv7m/cpu.c

@@ -0,0 +1,35 @@
+/*
+ * (C) Copyright 2010,2011
+ * Vladimir Khusainov, Emcraft Systems, vlad@emcraft.com
+ *
+ * (C) Copyright 2015
+ * Kamil Lulko, <kamil.lulko@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/armv7m.h>
+
+/*
+ * This is called right before passing control to
+ * the Linux kernel point.
+ */
+int cleanup_before_linux(void)
+{
+	return 0;
+}
+
+/*
+ * Perform the low-level reset.
+ */
+void reset_cpu(ulong addr)
+{
+	/*
+	 * Perform reset but keep priority group unchanged.
+	 */
+	writel((V7M_AIRCR_VECTKEY << V7M_AIRCR_VECTKEY_SHIFT)
+		| (V7M_SCB->aircr & V7M_AIRCR_PRIGROUP_MSK)
+		| V7M_AIRCR_SYSRESET, &V7M_SCB->aircr);
+}

u-boot/arch/arm/cpu/armv7m/start.S

@@ -0,0 +1,15 @@
+/*
+ * (C) Copyright 2015
+ * Kamil Lulko, <kamil.lulko@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+.globl	reset
+.type reset, %function
+reset:
+	b	_main
+
+.globl	c_runtime_cpu_setup
+c_runtime_cpu_setup:
+	mov	pc, lr