usb: add trezor1-like debuglink

src/main.py

@@ -33,6 +33,30 @@ usb_wire = io.HID(
         0xc0,              # END_COLLECTION
     ]),
 )
+if __debug__:
+    usb_debug = io.HID(
+        iface_num=0x04,
+        ep_in=0x85,
+        ep_out=0x04,
+        report_desc=bytes([
+            0x06, 0x01, 0xff,  # USAGE_PAGE (Vendor Defined)
+            0x09, 0x01,        # USAGE (1)
+            0xa1, 0x01,        # COLLECTION (Application)
+            0x09, 0x20,        # USAGE (Input Report Data)
+            0x15, 0x00,        # LOGICAL_MINIMUM (0)
+            0x26, 0xff, 0x00,  # LOGICAL_MAXIMUM (255)
+            0x75, 0x08,        # REPORT_SIZE (8)
+            0x95, 0x40,        # REPORT_COUNT (64)
+            0x81, 0x02,        # INPUT (Data,Var,Abs)
+            0x09, 0x21,        # USAGE (Output Report Data)
+            0x15, 0x00,        # LOGICAL_MINIMUM (0)
+            0x26, 0xff, 0x00,  # LOGICAL_MAXIMUM (255)
+            0x75, 0x08,        # REPORT_SIZE (8)
+            0x95, 0x40,        # REPORT_COUNT (64)
+            0x91, 0x02,        # OUTPUT (Data,Var,Abs)
+            0xc0,              # END_COLLECTION
+        ]),
+    )
 usb_vcp = io.VCP(
     iface_num=0x01,
     data_iface_num=0x02,
@@ -72,6 +96,8 @@ usb = io.USB(
     serial_number="000000000000000000000000",
 )
 usb.add(usb_wire)
+if __debug__:
+    usb.add(usb_debug)
 usb.add(usb_vcp)
 usb.add(usb_u2f)
 
@@ -96,6 +122,8 @@ fido_u2f.boot(usb_u2f)
 
 # initialize the wire codec and start the USB
 wire.setup(usb_wire)
+if __debug__:
+    wire.setup(usb_debug)
 usb.open()
 
 # load default homescreen