sandbox: block driver using host file/device as backing store

Provide a way to use any host file or device as a block device in U-Boot.
This can be used to provide filesystem access within U-Boot to an ext2
image file on the host, for example.

The support is plumbed into the filesystem and partition interfaces.

We don't want to print a message in the driver every time we find a missing
device. Pass the information back to the caller where a message can be printed
if desired.

Signed-off-by: Henrik Nordström <henrik@henriknordstrom.net>
Signed-off-by: Simon Glass <sjg@chromium.org>
- Removed change to part.c get_device_and_partition()

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>

include/sandboxblockdev.h

@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2013, Henrik Nordstrom <henrik@henriknordstrom.net>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __SANDBOX_BLOCK_DEV__
+#define __SANDBOX_BLOCK_DEV__
+
+struct host_block_dev {
+	block_dev_desc_t blk_dev;
+	char *filename;
+	int fd;
+};
+
+int host_dev_bind(int dev, char *filename);
+
+#endif