Compile usb ip drivers into kernel

1. Create a new directory named usbip in "$ (KERNELSOURCE)/drivers/usb/" directory, copy all driver files into that directory. The directory file list below:
   | USB IP
   | ---- Stub. h
   | ---- Stub_tx.c
   | ---- Stub_rx.c
   | ---- Stub_dev.c
   | ---- Stub_main.c
   | ---- Usbip_common.h
   | ---- Usbip_common.c
   | ---- Usbip_event.c
   | ---- Vhci. h
   | ---- Vhci_hcd.c
   | ---- Vhci_rx.c
   | ---- Vhci_tx.c
   | ---- Vhci_sysfs.c
2. Create a Kconfig file in "usbip" directory with contents below:
   #
   # Usb ip driver configuration
   #
   Comment "usb ip Driver"
   Config USB IP
   Bool "usb ip support"
   Config USBIP_STUB
   Tristate "Usbip stub driver"
   Depends on USB IP
   Config USBIP_VHCI
   Tristate "usb ip vhci driver"
   Depends on USB IP
3. Modify the Kconfig file of its parent directory "usb", add contents:
   Source "drivers/usb IP/Kconfig"
   Then we can find a item named "usbip" in "Device Driver-> USB devices support" when we use "make menuconfig/xconfig ".
4. Create a Makefile file in "usbip" directory with contents below:
   Ksource? =/Lib/modules/$ (shell uname-R)/build
   Hcd_header: = $ (ksource)/Drivers/USB/CORE/HCD. h
   Usbip_common_mod-objs: = usbip_common.o usbip_event.o
   Usbip-objs: = stub_dev.o stub_main.o stub_rx.o stub_tx.o
   Vhci-HCD-objs: = vhci_sysfs.o vhci_tx.o vhci_rx.o vhci_hcd.o
   OBJ-$ (config_usbip) + = usbip_common_mod.o
   OBJ-$ (config_usbip_stub) + = usb ip. o
   OBJ-$ (config_usbip_vhci) + = vhci-hcd.o
   Extra_cflags + =-dhcd_header =/"$ (hcd_header )/"
5. Modify the Makefile file of its parent directory "usb", add contents:
   OBJ-$ (config_usbip) + = usb ip/
   All things done!