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/cmd/zip.c

@@ -0,0 +1,42 @@
+/*
+ * (C) Copyright 2012
+ * Lei Wen <leiwen@marvell.com>, Marvell Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <command.h>
+
+static int do_zip(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	unsigned long src, dst;
+	unsigned long src_len, dst_len = ~0UL;
+
+	switch (argc) {
+		case 5:
+			dst_len = simple_strtoul(argv[4], NULL, 16);
+			/* fall through */
+		case 4:
+			src = simple_strtoul(argv[1], NULL, 16);
+			src_len = simple_strtoul(argv[2], NULL, 16);
+			dst = simple_strtoul(argv[3], NULL, 16);
+			break;
+		default:
+			return cmd_usage(cmdtp);
+	}
+
+	if (gzip((void *) dst, &dst_len, (void *) src, src_len) != 0)
+		return 1;
+
+	printf("Compressed size: %ld = 0x%lX\n", dst_len, dst_len);
+	setenv_hex("filesize", dst_len);
+
+	return 0;
+}
+
+U_BOOT_CMD(
+	zip,	5,	1,	do_zip,
+	"zip a memory region",
+	"srcaddr srcsize dstaddr [dstsize]"
+);