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/cache.c

@@ -0,0 +1,106 @@
+/*
+ * (C) Copyright 2000
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+/*
+ * Cache support: switch on or off, get status
+ */
+#include <common.h>
+#include <command.h>
+#include <linux/compiler.h>
+
+static int parse_argv(const char *);
+
+void __weak invalidate_icache_all(void)
+{
+	/* please define arch specific invalidate_icache_all */
+	puts("No arch specific invalidate_icache_all available!\n");
+}
+
+static int do_icache(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	switch (argc) {
+	case 2:			/* on / off	*/
+		switch (parse_argv(argv[1])) {
+		case 0:
+			icache_disable();
+			break;
+		case 1:
+			icache_enable();
+			break;
+		case 2:
+			invalidate_icache_all();
+			break;
+		}
+		break;
+	case 1:			/* get status */
+		printf("Instruction Cache is %s\n",
+			icache_status() ? "ON" : "OFF");
+		return 0;
+	default:
+		return CMD_RET_USAGE;
+	}
+	return 0;
+}
+
+void __weak flush_dcache_all(void)
+{
+	puts("No arch specific flush_dcache_all available!\n");
+	/* please define arch specific flush_dcache_all */
+}
+
+static int do_dcache(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	switch (argc) {
+	case 2:			/* on / off */
+		switch (parse_argv(argv[1])) {
+		case 0:
+			dcache_disable();
+			break;
+		case 1:
+			dcache_enable();
+			break;
+		case 2:
+			flush_dcache_all();
+			break;
+		}
+		break;
+	case 1:			/* get status */
+		printf("Data (writethrough) Cache is %s\n",
+			dcache_status() ? "ON" : "OFF");
+		return 0;
+	default:
+		return CMD_RET_USAGE;
+	}
+	return 0;
+}
+
+static int parse_argv(const char *s)
+{
+	if (strcmp(s, "flush") == 0)
+		return 2;
+	else if (strcmp(s, "on") == 0)
+		return 1;
+	else if (strcmp(s, "off") == 0)
+		return 0;
+
+	return -1;
+}
+
+
+U_BOOT_CMD(
+	icache,   2,   1,     do_icache,
+	"enable or disable instruction cache",
+	"[on, off, flush]\n"
+	"    - enable, disable, or flush instruction cache"
+);
+
+U_BOOT_CMD(
+	dcache,   2,   1,     do_dcache,
+	"enable or disable data cache",
+	"[on, off, flush]\n"
+	"    - enable, disable, or flush data (writethrough) cache"
+);