基于USB连接的系统启动和下载方式优化设计研究

Research on Optimization System Boot and Download Mode Based on USB Connection

多数智能手机产品的系统软件启动和下载都是通过USB连接方式进行,通过硬件的下拉管脚或者启动按键方式进行硬件握手,进入USB下载模式。对于车载模块和手表系列产品,硬件没有设计外部按键和相关测试点,无法完全保证这类产品的正常下载,不能保证在下载出现异常时,让产品能够再次、多次下载,并正常启动,以致产品变成“砖头”。通过对启动和下载的软件过程进行深挖分析,对软件处理流程和分页数据写入的先后顺序进行重新设计,进行启动和下载流程的优化,同时通过断电切片试验验证优化设计后的方案的正确性,彻底解决了硬件上不支持下拉管脚或者启动按键的产品不能确保系统正常启动和下载的问题。该研究成果可为相关应用与研究提供参考。

In the form of vehicle-mounted modules and watches, because there are no external buttons or relevant test points on the hardware, there is no guarantee that the kind of product will be able to download multiple times in case of a download exception and when starting normally. In order to prevent the product from becoming a "brick", by analyzing deeply the software process of the system boot and download, redesign the software processing process and the sequence of writing paging data, optimize the startup and download process. At the same time by slicing test verifies the correctness of the optimized scheme, completely solve the problem which ensure the products without strap pin or Boot key to be normally started and downloaded.This research results can provide reference for related application and research.