基于压缩和差分算法的嵌入式平台远程更新设计与分析

Design and analysis of remote update of embedded platform based on compression and difference algorithm

传统的嵌入式远程更新方案普遍采用整包更新方式,这种方式更新数据量大,占用网络宽带时间长,同时也增加了设备的功耗。针对这些问题,提出了以减少更新数据量为核心的两种远程更新方案。这两种方案分别使用LZ77压缩和BSDiff差分算法处理更新包,减少需要传输的数据量;同时,在数据传输方面增加断点续传功能,实现终端从断线的地方继续获取数据,以此达到节省设备流量和功耗的目的。另外,设计了一种FLASH分区方式,优化了本地自更新操作的流程,去除了多余的拷贝操作。将这两种方案在STM32F407ZGT6和NB-IoT搭建的嵌入式平台中进行验证测试。实验结果显示,这两种更新方案的平均更新效率与整包更新的方式相比分别提升了26.44%和72.17%。

The traditional embedded remote update scheme generally adopts the whole package update method,which has massive update data,takes up a long time of network broadband,and increases the power consumption of the equipment too.Aiming at these problems,two remote update schemes with the core of reducing the amount of updated data were proposed.The two schemes use LZ77 compression and BSDiff differential algorithm respectively to process the updated package so as to reduce the amount of data to be transmitted.At the same time,the function of breakpoint resume was added in the aspect of data transmission so that the terminal could continue to obtain data from the breakpoint,thus achieving the purpose of saving device flow and power consumption.In addition,a FLASH partitioning method was designed to optimize the process of local self-update operation and eliminate redundant copy operation.The two schemes were tested in the embedded platform built by STM32 F407 ZGT6 and NB-IoT.The experimental results show that the average update efficiencies of these two update schemes are improved by 26.44%and 72.17%respectively compared with the whole package update method.