Abstract: Aiming at the shortage of the traditional method of embedded system upgrade, a project of embedded system online upgrade based on TFFS is put forward. The operation core, application and bootRom can be online upgraded from remote host without ICE. First of all, the whole project is described, secondly, some key techniques, such as the TFFS file system, the design of the start flow and system backup are discussed, then the realization of the project is discussed in detail, the reliability is designed at last. This project is implemented and verified in the embedded AFTN gateway system.

Key words: TFFS; Embedded system; Online upgrade; VxWorks; AFTN

摘要： 针对传统嵌入式系统升级方式的不足，提出了一种基于TFFS 的嵌入式系统在线升级方案，实现了不需仿真器就可远程在线升级操作系统内核和应用程序以及引导映像的功能。描述了总体方案，讨论了关键技术，包括TFFS 文件系统、启动流程设计和双机热备份，论述了方案的具体实现，进行了可靠性设计。该方案在嵌入式航空固定电信网(AFTN)网关系统中得到了应用和验证。

关键词: TFFS；嵌入式系统；在线升级；VxWorks；航空固定电信网