Abstract: Concerning the shortages of traditional embedded software updates, a new on-site update method with high-reliability was proposed, which achieved embedded system software updating by copying update files from a SD card to the flash partitions of the embedded device. On condition of fast update, the compatibility detection of update files for fault-avoidance, the double-Bootloader design, the test and verification of the update files, and the exception handling mechanism were adopted to effectively improve fault-avoidance and fault-tolerance properties of the software. The high reliability of this method is proved through the reliability assessment based on the Nelson model and the application in the product.

Key words: embedded system software, on-site update, fault-avoidance and fault-tolerance, reliability assessment

摘要： 针对传统嵌入式软件更新方法的不足，提出了一种高可靠性的嵌入式软件现场更新方法，通过读取SD卡上的更新文件来更新嵌入式设备的Flash分区，从而实现设备软件的更新。该方法在保证快速更新功能的前提下，采用更新文件兼容性避错检测、双Bootloader设计、更新文件验证及软件异常处理机制，有效提高了软件的避错、容错性能。通过Nelson模型可靠性评估及其在产品中的应用，证明该更新方法具有高可靠性。

关键词: 嵌入式软件, 现场更新, 避错容错, 可靠性评估