BLE lib
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Diff: services/DFUService.h
- Revision:
- 0:289fd2dae405
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/services/DFUService.h Fri Dec 19 18:54:46 2014 +0000 @@ -0,0 +1,115 @@ +/* mbed Microcontroller Library + * Copyright (c) 2006-2013 ARM Limited + * + * 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 __BLE_DFU_SERVICE_H__ +#define __BLE_DFU_SERVICE_H__ + +#include "BLEDevice.h" +#include "UUID.h" + +extern "C" void bootloader_start(void); + +extern const uint8_t DFUServiceBaseUUID[]; +extern const uint16_t DFUServiceShortUUID; +extern const uint16_t DFUServiceControlCharacteristicShortUUID; + +extern const uint8_t DFUServiceUUID[]; +extern const uint8_t DFUServiceControlCharacteristicUUID[]; +extern const uint8_t DFUServicePacketCharacteristicUUID[]; + +class DFUService { +public: + /** + * Signature for the handover callback. The application may provide such a + * callback when setting up the DFU service, in which case it will be + * invoked before handing control over to the bootloader. + */ + typedef void (*ResetPrepare_t)(void); + +public: + DFUService(BLEDevice &_ble, ResetPrepare_t _handoverCallback = NULL) : + ble(_ble), + controlBytes(), + packetBytes(), + controlPoint(DFUServiceControlCharacteristicUUID, controlBytes, SIZEOF_CONTROL_BYTES, SIZEOF_CONTROL_BYTES, + GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_WRITE | GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY), + packet(DFUServicePacketCharacteristicUUID, packetBytes, SIZEOF_PACKET_BYTES, SIZEOF_PACKET_BYTES, + GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_WRITE_WITHOUT_RESPONSE) { + static bool serviceAdded = false; /* We should only ever need to add the DFU service once. */ + if (serviceAdded) { + return; + } + + /* Set an initial value for control bytes so that the application's DFUService can + * be distinguished from the real DFU service provided by the bootloader. */ + controlBytes[0] = 0xFF; + controlBytes[1] = 0xFF; + + GattCharacteristic *dfuChars[] = {&controlPoint, &packet}; + GattService dfuService(DFUServiceUUID, dfuChars, sizeof(dfuChars) / sizeof(GattCharacteristic *)); + + ble.addService(dfuService); + handoverCallback = _handoverCallback; + serviceAdded = true; + + ble.onDataWritten(this, &DFUService::onDataWritten); + } + + uint16_t getControlHandle(void) { + return controlPoint.getValueAttribute().getHandle(); + } + + /** + * This callback allows the DFU service to receive the initial trigger to + * handover control to the bootloader; but first the application is given a + * chance to clean up. + */ + virtual void onDataWritten(const GattCharacteristicWriteCBParams *params) { + if (params->charHandle == controlPoint.getValueAttribute().getHandle()) { + /* At present, writing anything will do the trick--this needs to be improved. */ + if (handoverCallback) { + handoverCallback(); + } + + bootloader_start(); + } + } + +private: + static const unsigned SIZEOF_CONTROL_BYTES = 2; + static const unsigned SIZEOF_PACKET_BYTES = 20; + + static ResetPrepare_t handoverCallback; /**< application specific handover callback. */ + +private: + BLEDevice &ble; + uint8_t controlBytes[SIZEOF_CONTROL_BYTES]; + uint8_t packetBytes[SIZEOF_PACKET_BYTES]; + + /**< Writing to the control characteristic triggers the handover to dfu- + * bootloader. At present, writing anything will do the trick--this needs + * to be improved. */ + GattCharacteristic controlPoint; + + /**< The packet characteristic in this service doesn't do anything meaningful, but + * is only a placeholder to mimic the corresponding characteristic in the + * actual DFU service implemented by the bootloader. Without this, some + * FOTA clients might get confused as service definitions change after + * handing control over to the bootloader. */ + GattCharacteristic packet; +}; + +#endif /* #ifndef __BLE_DFU_SERVICE_H__*/