PCI扩展ROM机制的实现方法

Implementation of PCI Expansion ROM Mechanism

该文描述了一种实现PCI扩展ROM机制的方法。该方法以一个PCI接口芯片的设计为依托,不但支持系统BIOS在PCI存储器空间对扩展ROM寻址,还通过寄存器间址的方式在PCI输入输出空间实现了PCI扩展ROM。这种双重空间寻址方式满足了以任意字节组合方式对扩展ROM访问的要求。对面向PC机卡式模块的PCI设备开发,尤其是实现扩展ROM机制,该设计提供了一个实例。

This paper describes an approach to implementing PCI Expansion ROM Mechanism.The implementation is based on a design of PCI interface chip.Our design make the system POST(Power-On Self-Test)program have the capability of locating the ROM in a non-conflicting address range of memory address space then shadow it and execute its initialization code.After that,other program also can access the expansion ROM in I/O address space by register indirect addressing.So our design can handle any combination of byte enables.