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/sh/lib/zimageboot.c

@@ -0,0 +1,65 @@
+/*
+ * (C) Copyright 2010
+ *   Renesas Solutions Corp.
+ *   Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+/*
+ * Linux SuperH zImage loading and boot
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/zimage.h>
+
+int do_sh_zimageboot (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	ulong (*zboot_entry)(int, char * const []) = NULL;
+	char *s0, *s1;
+	unsigned char *param = NULL;
+	char *cmdline;
+	char *bootargs;
+
+	disable_interrupts();
+
+	if (argc >= 3) {
+		/* argv[1] holds the address of the zImage */
+		s0 = argv[1];
+		/* argv[2] holds the address of zero page */
+		s1 = argv[2];
+	} else {
+		goto exit;
+	}
+
+	if (s0)
+		zboot_entry = (ulong (*)(int, char * const []))simple_strtoul(s0, NULL, 16);
+
+	/* empty_zero_page */
+	if (s1)
+		param = (unsigned char*)simple_strtoul(s1, NULL, 16);
+
+	/* Linux kernel command line */
+	cmdline = (char *)param + COMMAND_LINE;
+	bootargs = getenv("bootargs");
+
+	/* Clear zero page */
+	/* cppcheck-suppress nullPointer */
+	memset(param, 0, 0x1000);
+
+	/* Set commandline */
+	strcpy(cmdline, bootargs);
+
+	/* Boot */
+	zboot_entry(0, NULL);
+
+exit:
+	return -1;
+}
+
+U_BOOT_CMD(
+	zimageboot, 3, 0,	do_sh_zimageboot,
+	"Boot zImage for Renesas SH",
+	""
+);