Data-transfer interface should now be functionally complete.

src/core/hw.c

@@ -0,0 +1,68 @@
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <gpxe/refcnt.h>
+#include <gpxe/xfer.h>
+#include <gpxe/open.h>
+
+/** @file
+ *
+ * "Hello World" data source
+ *
+ */
+
+struct hw {
+	struct refcnt refcnt;
+	struct xfer_interface xfer;
+};
+
+static const char hw_msg[] = "Hello world!\n";
+
+static void hw_finished ( struct hw *hw, int rc ) {
+	xfer_nullify ( &hw->xfer );
+	xfer_close ( &hw->xfer, rc );
+	ref_put ( &hw->refcnt );
+}
+
+static void hw_xfer_close ( struct xfer_interface *xfer, int rc ) {
+	struct hw *hw = container_of ( xfer, struct hw, xfer );
+
+	hw_finished ( hw, rc );
+}
+
+static int hw_xfer_request ( struct xfer_interface *xfer, off_t start __unused,
+			     int whence __unused, size_t len __unused ) {
+	struct hw *hw = container_of ( xfer, struct hw, xfer );
+
+	xfer_deliver_raw ( xfer, hw_msg, sizeof ( hw_msg ) );
+	hw_finished ( hw, 0 );
+	return 0;
+}
+
+static struct xfer_interface_operations hw_xfer_operations = {
+	.close		= hw_xfer_close,
+	.vredirect	= ignore_xfer_vredirect,
+	.request	= hw_xfer_request,
+	.seek		= ignore_xfer_seek,
+	.deliver_iob	= xfer_deliver_as_raw,
+	.deliver_raw	= ignore_xfer_deliver_raw,
+};
+
+static int hw_open ( struct xfer_interface *xfer, struct uri *uri __unused ) {
+	struct hw *hw;
+
+	hw = malloc ( sizeof ( *hw ) );
+	if ( ! hw )
+		return -ENOMEM;
+	memset ( hw, 0, sizeof ( *hw ) );
+	xfer_init ( &hw->xfer, &hw_xfer_operations, &hw->refcnt );
+
+	xfer_plug_plug ( &hw->xfer, xfer );
+	return 0;
+}
+
+struct uri_opener hw_uri_opener __uri_opener = {
+	.scheme = "hw",
+	.open = hw_open,
+};