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/mach-rockchip/rk3036-board-spl.c

@@ -0,0 +1,62 @@
+/*
+ * (C) Copyright 2015 Rockchip Electronics Co., Ltd
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <debug_uart.h>
+#include <asm/io.h>
+#include <asm/arch/grf_rk3036.h>
+#include <asm/arch/hardware.h>
+#include <asm/arch/sdram_rk3036.h>
+#include <asm/arch/timer.h>
+#include <asm/arch/uart.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define GRF_BASE	0x20008000
+static struct rk3036_grf * const grf = (void *)GRF_BASE;
+
+#define DEBUG_UART_BASE	0x20068000
+
+extern void back_to_bootrom(void);
+
+void board_init_f(ulong dummy)
+{
+#ifdef EARLY_DEBUG
+	/*
+	 * NOTE: sd card and debug uart use same iomux in rk3036,
+	 * so if you enable uart,
+	 * you can not boot from sdcard
+	 */
+	rk_clrsetreg(&grf->gpio1c_iomux,
+		     GPIO1C3_MASK << GPIO1C3_SHIFT |
+		     GPIO1C2_MASK << GPIO1C2_SHIFT,
+		     GPIO1C3_UART2_SOUT << GPIO1C3_SHIFT |
+		     GPIO1C2_UART2_SIN << GPIO1C2_SHIFT);
+	debug_uart_init();
+#endif
+	rockchip_timer_init();
+	sdram_init();
+
+	/* return to maskrom */
+	back_to_bootrom();
+}
+
+/* Place Holders */
+void board_init_r(gd_t *id, ulong dest_addr)
+{
+	/*
+	 * Function attribute is no-return
+	 * This Function never executes
+	 */
+	while (1)
+		;
+}
+
+void hang(void)
+{
+	while (1)
+		;
+}