/* * Copyright (C) 2006 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef ANDROID_USB_API_ADBWINUSBAPI_H__ #define ANDROID_USB_API_ADBWINUSBAPI_H__ /** \file Contains declarations required to link AdbWinApi and AdbWinUsbApi DLLs. */ /** \brief Function prototype for InstantiateWinUsbInterface routine exported from AdbWinUsbApi.dll In order to provide backward compatibility with the systems that still run legacy (custom) USB drivers, and have not installed WINUSB.DLL we need to split functionality of our ADB API on Windows between two DLLs: AdbWinApi, and AdbWinUsbApi. AdbWinApi is fully capable of working on top of the legacy driver, but has no traces to WinUsb. AdbWinUsbApi is capable of working on top of WinUsb API. We are forced to do this split, because we can have dependency on WINUSB.DLL in the DLL that implements legacy API. The problem is that customers may have a legacy driver that they don't want to upgrade to WinUsb, so they may not have WINUSB.DLL installed on their machines, but they still must be able to use ADB. So, the idea behind the split is as such. When AdbWinApi.dll is loaded into a process, it will check WINUSB.DLL installation (by checking existance of C:\Windows\System32\winusb.dll). If WINUSB.DLL is installed, AdbWinApi will also load AdbWinUsbApi.dll (by calling LoadLibrary), and will extract address of InstantiateWinUsbInterface routine exported from AdbWinUsbApi.dll. Then this routine will be used to instantiate AdbInterfaceObject instance on condition that it is confirmed that USB driver underneath us is in deed WinUsb. */ typedef class AdbInterfaceObject* \ (__cdecl *PFN_INSTWINUSBINTERFACE)(const wchar_t*); #endif // ANDROID_USB_API_ADBWINUSBAPI_H__