[efi] Add a USB host controller driver based on EFI_USB_IO_PROTOCOL

Allow iPXE to coexist with other USB device drivers, by attaching to
the EFI_USB_IO_PROTOCOL instances provided by the UEFI platform
firmware.

The EFI_USB_IO_PROTOCOL is an unsurprisingly badly designed
abstraction of a USB device.  The poor design choices intrinsic in the
UEFI specification prevent efficient operation as a network device,
with the result that devices operated using the EFI_USB_IO_PROTOCOL
operate approximately two orders of magnitude slower than devices
operated using our native EHCI or xHCI host controller drivers.

Since the performance is so abysmally slow, and since the underlying
problems are due to fundamental architectural mistakes in the UEFI
specification, support for the EFI_USB_IO_PROTOCOL host controller
driver is left as disabled by default.  Users are advised to use the
native iPXE host controller drivers instead.

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

src/include/ipxe/errfile.h

@@ -85,6 +85,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #define ERRFILE_uhci		     ( ERRFILE_DRIVER | 0x000b0000 )
 #define ERRFILE_usbhid		     ( ERRFILE_DRIVER | 0x000c0000 )
 #define ERRFILE_usbkbd		     ( ERRFILE_DRIVER | 0x000d0000 )
+#define ERRFILE_usbio		     ( ERRFILE_DRIVER | 0x000e0000 )
 
 #define ERRFILE_nvs		     ( ERRFILE_DRIVER | 0x00100000 )
 #define ERRFILE_spi		     ( ERRFILE_DRIVER | 0x00110000 )

src/include/ipxe/usb.h

@@ -68,7 +68,7 @@ enum usb_pid {
 struct usb_setup_packet {
 	/** Request */
 	uint16_t request;
-	/** Value paramer */
+	/** Value parameter */
 	uint16_t value;
 	/** Index parameter */
 	uint16_t index;
@@ -91,6 +91,9 @@ struct usb_setup_packet {
 /** Vendor-specific request type */
 #define USB_TYPE_VENDOR ( 2 << 5 )
 
+/** Request recipient mask */
+#define USB_RECIP_MASK ( 0x1f << 0 )
+
 /** Request recipient is the device */
 #define USB_RECIP_DEVICE ( 0 << 0 )