嵌入式软件空中升级(OTA)时,需要升级包具备完整性、安全性和容错机制。本文研究了一系列嵌入式软件故障自动安全升级和在线评估技术,设计了安全回卷机制,设置了多重“阻隔点”,确保升级失败时能够安全恢复上一版本并通过硬件看门狗防止死锁;提出基于局部软件安全签名的升级包“合法性”验证技术;设置“防火墙”机制以保证核心数据区安全;“沙盒”运行模式,通过“试运行”验证可升级模块的安全性。

Over-the-air(OTA) of the embedded software requires that the alternative package be complete,legal,and restorable when updating fail.In the paper,a series of embedded security tools and techniques are proposed.Specifically,a rollback mechanism is designed that prevent deadlocks through the hardware watchdog.The validity of alternative package is verified by digital signature.We set up "firewall" to protect core data zone and "sandbox" using "trial run" to verify the modules.