add block support

This adds a simple block layer to barebox. Reading and writing
to block devices can be painfully slow without caching, so
add a simple caching layer here.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 32 insertions, 0 deletions

diff --git a/include/block.h b/include/block.h
new file mode 100644
index 0000000000..aaab4e3b36
--- /dev/null
+++ b/include/block.h
@@ -0,0 +1,32 @@
+#ifndef __BLOCK_H
+#define __BLOCK_H
+
+#include <driver.h>
+
+struct block_device;
+
+struct block_device_ops {
+	int (*read)(struct block_device *, void *buf, int block, int num_blocks);
+	int (*write)(struct block_device *, const void *buf, int block, int num_blocks);
+};
+
+struct block_device {
+	struct device_d *dev;
+	struct block_device_ops *ops;
+	int blockbits;
+	int num_blocks;
+	void *rdbuf; /* read buffer */
+	int rdbufsize;
+	int rdblock; /* start block in read buffer */
+	int rdblockend; /* end block in read buffer */
+	void *wrbuf; /* write buffer */
+	int wrblock; /* start block in write buffer */
+	int wrbufblocks; /* number of blocks currently in write buffer */
+	int wrbufsize; /* size of write buffer in blocks */
+	struct cdev cdev;
+};
+
+int blockdevice_register(struct block_device *blk);
+int blockdevice_unregister(struct block_device *blk);
+
+#endif /* __BLOCK_H */