[ncm] Add support for CDC-NCM USB Ethernet devices

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/drivers/net/ecm.h

@@ -0,0 +1,40 @@
+#ifndef _ECM_H
+#define _ECM_H
+
+/** @file
+ *
+ * CDC-ECM USB Ethernet driver
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <ipxe/usb.h>
+#include <ipxe/cdc.h>
+
+/** An Ethernet Functional Descriptor */
+struct ecm_ethernet_descriptor {
+	/** Descriptor header */
+	struct usb_descriptor_header header;
+	/** Descriptor subtype */
+	uint8_t subtype;
+	/** MAC addres string */
+	uint8_t mac;
+	/** Ethernet statistics bitmap */
+	uint32_t statistics;
+	/** Maximum segment size */
+	uint16_t mtu;
+	/** Multicast filter configuration */
+	uint16_t mcast;
+	/** Number of wake-on-LAN filters */
+	uint8_t wol;
+} __attribute__ (( packed ));
+
+extern struct ecm_ethernet_descriptor *
+ecm_ethernet_descriptor ( struct usb_configuration_descriptor *config,
+			  struct usb_interface_descriptor *interface );
+extern int ecm_fetch_mac ( struct usb_device *usb,
+			   struct ecm_ethernet_descriptor *desc,
+			   uint8_t *hw_addr );
+
+#endif /* _ECM_H */