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/fs/sandbox/Makefile

@@ -0,0 +1,13 @@
+#
+# Copyright (c) 2012, Google Inc.
+#
+# (C) Copyright 2006
+# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+#
+# (C) Copyright 2003
+# Pavel Bartusek, Sysgo Real-Time Solutions AG, pba@sysgo.de
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+obj-y := sandboxfs.o

u-boot/fs/sandbox/sandboxfs.c

@@ -0,0 +1,141 @@
+/*
+ * Copyright (c) 2012, Google Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <fs.h>
+#include <os.h>
+
+int sandbox_fs_set_blk_dev(struct blk_desc *rbdd, disk_partition_t *info)
+{
+	/*
+	 * Only accept a NULL struct blk_desc for the sandbox, which is when
+	 * hostfs interface is used
+	 */
+	return rbdd != NULL;
+}
+
+int sandbox_fs_read_at(const char *filename, loff_t pos, void *buffer,
+		       loff_t maxsize, loff_t *actread)
+{
+	loff_t size;
+	int fd, ret;
+
+	fd = os_open(filename, OS_O_RDONLY);
+	if (fd < 0)
+		return fd;
+	ret = os_lseek(fd, pos, OS_SEEK_SET);
+	if (ret == -1) {
+		os_close(fd);
+		return ret;
+	}
+	if (!maxsize) {
+		ret = os_get_filesize(filename, &size);
+		if (ret) {
+			os_close(fd);
+			return ret;
+		}
+
+		maxsize = size;
+	}
+
+	size = os_read(fd, buffer, maxsize);
+	os_close(fd);
+
+	if (size < 0) {
+		ret = -1;
+	} else {
+		ret = 0;
+		*actread = size;
+	}
+
+	return ret;
+}
+
+int sandbox_fs_write_at(const char *filename, loff_t pos, void *buffer,
+			loff_t towrite, loff_t *actwrite)
+{
+	ssize_t size;
+	int fd, ret;
+
+	fd = os_open(filename, OS_O_RDWR | OS_O_CREAT);
+	if (fd < 0)
+		return fd;
+	ret = os_lseek(fd, pos, OS_SEEK_SET);
+	if (ret == -1) {
+		os_close(fd);
+		return ret;
+	}
+	size = os_write(fd, buffer, towrite);
+	os_close(fd);
+
+	if (size == -1) {
+		ret = -1;
+	} else {
+		ret = 0;
+		*actwrite = size;
+	}
+
+	return ret;
+}
+
+int sandbox_fs_ls(const char *dirname)
+{
+	struct os_dirent_node *head, *node;
+	int ret;
+
+	ret = os_dirent_ls(dirname, &head);
+	if (ret)
+		return ret;
+
+	for (node = head; node; node = node->next) {
+		printf("%s %10lu %s\n", os_dirent_get_typename(node->type),
+		       node->size, node->name);
+	}
+
+	return 0;
+}
+
+int sandbox_fs_exists(const char *filename)
+{
+	loff_t size;
+	int ret;
+
+	ret = os_get_filesize(filename, &size);
+	return ret == 0;
+}
+
+int sandbox_fs_size(const char *filename, loff_t *size)
+{
+	return os_get_filesize(filename, size);
+}
+
+void sandbox_fs_close(void)
+{
+}
+
+int fs_read_sandbox(const char *filename, void *buf, loff_t offset, loff_t len,
+		    loff_t *actread)
+{
+	int ret;
+
+	ret = sandbox_fs_read_at(filename, offset, buf, len, actread);
+	if (ret)
+		printf("** Unable to read file %s **\n", filename);
+
+	return ret;
+}
+
+int fs_write_sandbox(const char *filename, void *buf, loff_t offset,
+		     loff_t len, loff_t *actwrite)
+{
+	int ret;
+
+	ret = sandbox_fs_write_at(filename, offset, buf, len, actwrite);
+	if (ret)
+		printf("** Unable to write file %s **\n", filename);
+
+	return ret;
+}