面向S3C2440的U-Boot分析与改进  

Analysis and Improvement of S3C2440-oriented U-Boot

作　　者：孙棣华[1] 龚康[1] 廖孝勇[1] 

机构地区：[1]重庆大学自动化学院,重庆400044

出　　处：《控制工程》2012年第5期881-884,共4页Control Engineering of China

基　　金：国家863计划(2006AA04A124)资助

摘　　要：针对目前U-Boot引导程序无法从大页Nandflash启动,以及不能同时支持从Nandflash和Norflash启动的问题,在不改变代码通用性的前提下对U-Boot进行了改进。首先分析U-Boot阶段1的启动原理和U-Boot通用性的实现方法;然后依据S3C24加处理器提供的Nandflash存储启动机制以及大页Nandflash数据操作原理,修改阶段1实现代码,添加从大页Nandflash启动;最后利用大页Nandflash和Norflash存储器读写数据的差异性以及两种存储启动方式实现的不同机理,添加S3C2440处理器自动判断从何种存储器启动的代码,实现U-Boot兼容Nandflash和Norflash启动的改进。通过在基于S3C2440处理器的目标板上运行,结果证明对U-Boot所做的改进具有有效性,扩展了U-Boot的适用范围,增强了代码兼容性。Aiming at the issues that U - Boot can＇t boot from the large page of Nandflash and not support boot both from Nandflash and Norilash, this paper improved the U - Boot under the premise of codes generality unchanged. Firstly, analyze the stage 1 mechanism of U -Boot and implementation principle of the generality; secondly, according to the booting mechanism from Nandflash provided by S3C2440 and data manipulation principles of large page Nandflash, alter the implementation codes to add booting from large page Nand- flash; finally, add the codes that S3C2440 processor automatically judged to start from what kind of memory to achieve the improvement compatible booting both from Nandflash and Norflash. The running results prove that the U - Boot improvement given by this paper is feasible, expands the U - Boot applicable scope and enhances the compatibility of the codes.

关 键 词：U—Boot引导程序 内存映射 通用性 大页Nandflash 双启动 

分 类 号：TP27[自动化与计算机技术—检测技术与自动化装置]