【经验】Silicon Labs的蓝牙SoC EFR32BG22如何进行在线的OTA升级？

SILICON LABS的蓝牙SoC EFR32BG目前已经能够支持到蓝牙5.2，工艺升级后的EFR32BG22的功耗能够达到接收4.1mA，0dbm发射功耗3.6mA，休眠功耗低至1.4uA，如此低的功耗，能够大幅延长蓝牙设备的电池续航时间。

目前SiliconLabs提供的默认的OTA升级方式是In-place方式，流程为：

1、  APP发起OTA，显示连接断开，搜索OTA设备。

2、  EFR32BG22断开连接并重新启动；

3、  EFR32BG22 重启后以”OTA”广播；

4、  APP连接OTA并开始OTA升级；

5、  升级完成后EFR32BG22重启，升级成功。

这种方式占用的空间最小，但是可能在实际应用时，有些情况大家更喜欢传统的在线升级，链接不断开。本文介绍下方法。

首先需要选择一个Bootloader，本文以Internal Flash Bootloader为例，在ThunderBoard EFR32BG22的平台上进行操作：

然后，以SOC-Empty为例：

然后，复制Bootloader的API文件到工程中：

C:\SiliconLabs\SimplicityStudio\v4\developer\sdks\gecko_sdk_suite\v2.7\platform\bootloader\api\*

使用如下代码替换工程的app.c

//////////////////////////////////分割线////////////////////////////////////////////////

/***********************************************************************************************//**

 * \file   app.c

 * \brief  This example shows how to do Bluetooth OTA update under application control.

 *

 *  For more details about the Bluetooth OTA, refer to application note AN1086.

 *

 ***************************************************************************************************

 * <b> (C) Copyright 2018 Silicon Labs, http://www.silabs.com</b>

 ***************************************************************************************************

 * This file is licensed under the Silabs License Agreement. See the file

 * "Silabs_License_Agreement.txt" for details. Before using this software for

 * any purpose, you must agree to the terms of that agreement.

 **************************************************************************************************/

/* Bluetooth stack headers */

#include "bg_types.h"

#include "native_gecko.h"

#include "gatt_db.h"

#include "app.h"

#if DEBUG_LEVEL

/* printf debugging is enabled */

#include "retargetserial.h"

#include <stdio.h>

#define uart_flush RETARGET_SerialFlush

#else

/* debug prints are DISABLED - replace printf etc. with empty implementation */

#define printf(fmt, ...) (0)

#define uart_flush() (0)

#endif

#include "btl_interface.h"

#include "btl_interface_storage.h"

static void bootMessage(struct gecko_msg_system_boot_evt_t *bootevt);

static BootloaderInformation_t bldInfo;

static BootloaderStorageSlot_t slotInfo;

/* OTA variables */

static uint32 ota_image_position = 0;

static uint8 ota_in_progress = 0;

static uint8 ota_image_finished = 0;

static uint16 ota_time_elapsed = 0;

static int32_t get_slot_info()

{

    int32_t err;

    bootloader_getInfo(&bldInfo);

    printf("Gecko bootloader version: %u.%u\r\n", (bldInfo.version & 0xFF000000) >> 24, (bldInfo.version & 0x00FF0000) >> 16);

    err = bootloader_getStorageSlotInfo(0, &slotInfo);

    if(err == BOOTLOADER_OK)

    {

       printf("Slot 0 starts @ 0x%8.8x, size %u bytes\r\n", slotInfo.address, slotInfo.length);

    }

    else

    {

       printf("Unable to get storage slot info, error %x\r\n", err);

    }

    return(err);

}

static void erase_slot_if_needed()

{

    uint32_t offset = 0;

    uint8_t buffer[256];

    int i;

    int dirty = 0;

    int32_t err = BOOTLOADER_OK;

    int num_blocks = 0;

    /* check the download area content by reading it in 256-byte blocks */

    num_blocks = slotInfo.length / 256;

    while((dirty == 0) && (offset < 256*num_blocks) && (err == BOOTLOADER_OK))

    {

       err = bootloader_readStorage(0, offset, buffer, 256);

       if(err == BOOTLOADER_OK)

       {

           i=0;

           while(i<256)

           {

              if(buffer[i++] != 0xFF)

              {

                  dirty = 1;

                  break;

              }

           }

           offset += 256;

       }

       printf(".");

    }

    if(err != BOOTLOADER_OK)

    {

       printf("error reading flash! %x\r\n", err);

    }

    else if(dirty)

    {

       printf("download area is not empty, erasing...\r\n");

       bootloader_eraseStorageSlot(0);

       printf("done\r\n");

    }

    else

    {

       printf("download area is empty\r\n");

    }

    return;

}

static void print_progress()

{

    // estimate transfer speed in kbps

    int kbps = ota_image_position*8/(1024*ota_time_elapsed);

    printf("pos: %u, time: %u, kbps: %u\r\n", ota_image_position, ota_time_elapsed, kbps);

}

void appMain(gecko_configuration_t *pconfig)

{

#if DISABLE_SLEEP > 0

    pconfig->sleep.flags = 0;

#endif

#if DEBUG_LEVEL

    RETARGET_SerialInit();

#endif

      // Initialize stack

      gecko_init(pconfig);

      while (1) {

        /* Event pointer for handling events */

        struct gecko_cmd_packet* evt;

#if DEBUG_LEVEL

        /* if there are no events pending then the next call to gecko_wait_event() may cause

         * device go to deep sleep. Make sure that debug prints are flushed before going to sleep */

        if (!gecko_event_pending()) {

            uart_flush();

        }

#endif

        /* Check for stack event. */

        evt = gecko_wait_event();

        /* Handle events */

        switch (BGLIB_MSG_ID(evt->header)) {

          /* This boot event is generated when the system boots up after reset.

           * Do not call any stack commands before receiving the boot event.

           * Here the system is set to start advertising immediately after boot procedure. */

          case gecko_evt_system_boot_id:

#if DEBUG_LEVEL

           bootMessage(&(evt->data.evt_system_boot));

#endif

           /* 1 second soft timer, used for performance statistics during OTA file upload */

           gecko_cmd_hardware_set_soft_timer(32768, 0, 0);

            /* set advertising interval to 100 ms */

            gecko_cmd_le_gap_set_advertise_timing(0, 160, 160, 0, 0);

            /* Start general advertising and enable connections. */

            printf("boot event - starting advertising\r\n");

            gecko_cmd_le_gap_start_advertising(0, le_gap_general_discoverable, le_gap_connectable_scannable);

            /* bootloader init must be called before calling other bootloader_xxx API calls */

            bootloader_init();

            /* read slot information from bootloader */

            if(get_slot_info() == BOOTLOADER_OK)

            {

             /* the download area is erased here (if needed), prior to any connections are opened */

             erase_slot_if_needed();

            }

            else

            {

             printf("Check that you have installed correct type of Gecko bootloader!\r\n");

            }

            break;

          case gecko_evt_le_connection_opened_id:

           printf("connection opened\r\n");

           break;

          case gecko_evt_le_connection_closed_id:

           printf("connection closed, reason: 0x%2.2x\r\n", evt->data.evt_le_connection_closed.reason);

           if (ota_image_finished) {

              printf("Installing new image\r\n");

#if DEBUG_LEVEL

              uart_flush();

#endif

              bootloader_setImageToBootload(0);

              bootloader_rebootAndInstall();

           } else {

              /* Restart advertising after client has disconnected */

              gecko_cmd_le_gap_start_advertising(0, le_gap_general_discoverable, le_gap_connectable_scannable);

           }

           break;

          case gecko_evt_hardware_soft_timer_id:

           if(ota_in_progress)

           {

              ota_time_elapsed++;

              print_progress();

           }

           break;

           /* write operations to ota_data, ot_control characteristics are handled here :*/

          case gecko_evt_gatt_server_user_write_request_id:

          {

           uint32_t connection = evt->data.evt_gatt_server_user_write_request.connection;

           uint32_t characteristic = evt->data.evt_gatt_server_user_write_request.characteristic;

           if(characteristic == ota_control)

           {

              switch(evt->data.evt_gatt_server_user_write_request.value.data[0])

              {

              case 0://Erase and use slot 0

                 // NOTE: download are is NOT erased here, because the long blocking delay would result in supervision timeout

                 //bootloader_eraseStorageSlot(0);

                 ota_image_position=0;

                 ota_in_progress=1;

                 break;

              case 3://END OTA process

                 //wait for connection close and then reboot

                 ota_in_progress=0;

                 ota_image_finished=1;

                 printf("upload finished. received file size %u bytes\r\n", ota_image_position);

                 uart_flush();

                 break;

              default:

                 break;

              }

           } else if(characteristic == ota_data)

           {

              if(ota_in_progress)

              {

                 bootloader_writeStorage(0,//use slot 0

                        ota_image_position,

                           evt->data.evt_gatt_server_user_write_request.value.data,

                           evt->data.evt_gatt_server_user_write_request.value.len);

                 ota_image_position+=evt->data.evt_gatt_server_user_write_request.value.len;

              }

           }

           gecko_cmd_gatt_server_send_user_write_response(connection,characteristic,0);

          }

           break;

          default:

            break;

        }

      }

}

static void bootMessage(struct gecko_msg_system_boot_evt_t *bootevt)

{

    bd_addr local_addr;

    int i;

    printf("stack version: %u.%u.%u\r\n", bootevt->major, bootevt->minor, bootevt->patch);

    local_addr = gecko_cmd_system_get_bt_address()->address;

    printf("local BT device address: ");

    for(i=0;i<5;i++)

    {

       printf("%2.2x:", local_addr.addr[5-i]);

    }

    printf("%2.2x\r\n", local_addr.addr[0]);

}

//////////////////////////////////分割线/////////////////////////////////////////////////

使用如下替代gatt.xml

////////////////////////////////////分割线////////////////////////////////////

<?xml version="1.0" encoding="UTF-8" standalone="no"?>

<!--Custom BLE GATT-->

<gatt gatt_caching="false" generic_attribute_service="false" name="Custom BLE GATT" prefix="">

  <!--Generic Access-->

  <service advertise="false" name="Generic Access" requirement="mandatory" sourceId="org.bluetooth.service.generic_access" type="primary" uuid="1800">

    <informativeText>Abstract:  The generic_access service contains generic information about the device. All available Characteristics are readonly.  </informativeText>

    <!--Device Name-->

    <characteristic name="Device Name" sourceId="org.bluetooth.characteristic.gap.device_name" uuid="2A00">

      <informativeText/>

      <value length="16" type="utf-8" variable_length="false">EFR32WaitForOTA</value>

      <properties const="true" const_requirement="optional" read="true" read_requirement="mandatory"/>

    </characteristic>

    <!--Appearance-->

    <characteristic name="Appearance" sourceId="org.bluetooth.characteristic.gap.appearance" uuid="2A01">

      <informativeText>Abstract:  The external appearance of this device. The values are composed of a category (10-bits) and sub-categories (6-bits).  </informativeText>

      <value length="2" type="hex" variable_length="false">0000</value>

      <properties const="true" const_requirement="optional" read="true" read_requirement="mandatory"/>

    </characteristic>

  </service>

  <!--Silicon Labs OTA-->

  <service advertise="false" name="Silicon Labs OTA" requirement="mandatory" sourceId="com.silabs.service.ota" type="primary" uuid="1D14D6EE-FD63-4FA1-BFA4-8F47B42119F0">

    <informativeText>Abstract:  The Silicon Labs OTA Service enables over-the-air firmware update of the device.  </informativeText>

    <!--Silicon Labs OTA Control-->

    <characteristic id="ota_control" name="Silicon Labs OTA Control" sourceId="com.silabs.characteristic.ota_control" uuid="F7BF3564-FB6D-4E53-88A4-5E37E0326063">

      <informativeText>Abstract:  Silicon Labs OTA Control.  </informativeText>

      <value length="1" type="user" variable_length="false"/>

      <properties write="true" write_requirement="mandatory"/>

    </characteristic>

    <!--Silicon Labs OTA Data-->

    <characteristic id="ota_data" name="Silicon Labs OTA Data" sourceId="com.silabs.characteristic.ota_data" uuid="984227F3-34FC-4045-A5D0-2C581F81A153">

      <informativeText>Abstract:  Silicon Labs OTA Data.  </informativeText>

      <value length="255" type="user" variable_length="true"/>

      <properties write="true" write_no_response="true" write_no_response_requirement="mandatory" write_requirement="excluded"/>

    </characteristic>

  </service>

</gatt>

////////////////////////////////分割线/////////////////////////////////////////////

在图形界面导入gatt.xml，然后重新生成一下，如有需要可以添加一些：

重新生成后编译即可。

这样就可以按照原先的OTA方法，进行在线升级了。