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/include/asm/arch-stv0991/gpio.h

@@ -0,0 +1,22 @@
+/*
+ * (C) Copyright 2014
+ * Vikas Manocha, ST Micoelectronics, vikas.manocha@st.com
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __ASM_ARCH_STV0991_GPIO_H
+#define __ASM_ARCH_STV0991_GPIO_H
+
+enum gpio_direction {
+	GPIO_DIRECTION_IN,
+	GPIO_DIRECTION_OUT,
+};
+
+struct gpio_regs {
+	u32 data;		/* offset 0x0 */
+	u32 reserved[0xff];	/* 0x4--0x3fc */
+	u32 dir;		/* offset 0x400 */
+};
+
+#endif	/* __ASM_ARCH_STV0991_GPIO_H */