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/imx-common/spi.h

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2011 Freescale Semiconductor, Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __MXC_SPI_H_
+#define __MXC_SPI_H_
+
+/*
+ * Board-level chip-select callback
+ * Should return GPIO # to be used for chip-select
+ */
+
+int board_spi_cs_gpio(unsigned bus, unsigned cs);
+
+#endif