1. effective "Differential Upgrade" patch algorithm with high compression rate
2. effective recovery algorithm support recovery firmware in blocks which has low memory consumption and wear-leveling strategies, especially suitable for embeded devices with low RAM.
3. add sample ota bootloader project, see:
board\TencentOS_tiny_EVB_MX_Plus\KEIL\ota\ota_bootloader_recovery
4. add sample application project for download firmware through http, see:
board\TencentOS_tiny_EVB_MX_Plus\KEIL\ota\ota_application_download_through_http
5. add sample application project for download firmware through qcloud explorer console, see:
board\TencentOS_tiny_EVB_MX_Plus\KEIL\ota\ota_application_download_through_qcloud_iot_explorer
6. an OTA markdown document is pending

fix bug for lora incoming buffer

Update LoRaMac-node to Version 4.4.4，fix Security breach found by Tencent Blade Team please refer to security advisory - CVE-2020-11068

fix Security breach found by Tencent Blade Team please refer to security advisory - CVE-2020-11068

add nationz N32G4XM_STB board support

add mqtt client support for ec20 LTE DTU

modify ec20 recv mode

拉取更新

add pm2.5 demo for evbmx+

add iot explorer demo for LN882x

add support for LilyGO T-Display-GD32V board

fix cigcc  project

add udp support of ec20

add support for ec20

M26 Module

fix l073 lorawankeil  project

2020-05-07拉取更新

1. iot-hub sdk update to 3.2.0
2. iot-explorer update to 3.1.1

增加小熊派使用ESP8266+MQTT对接IoThub工程

2020-04-28拉取官方最新更新

1. make port_systick_reload the same as port_systick_config

Minor optimizes such as output info err etc