公开(公告)号：US20050165976A1

公开(公告)日：2005-07-28

申请号：US11082334

申请日：2005-03-17

Applicant: Ray Bittner ,  Michael Ginsberg

Inventor： Ray Bittner ,  Michael Ginsberg

IPC: G06F3/00 ,  G06F9/46 ,  G06F13/40

CPC classification number: G06F13/4027

Abstract: A multi-tasking operating system and method updates PCI address values in an extension register to ensure that various threads utilize the correct values when accessing peripheral PCI devices. When application program threads require access to a PCI device, the operating system writes the high order bits of the PCI device address to two places: (1) the extension register of the PCI host bridge to allow immediate addressing of the PCI device, and (2) separate memory locations associated with the threads. When a context switch occurs from a first thread to a second thread, the operating system retrieves the stored value from the memory location associated with the second thread and writes the value to the extension register. In this manner, when the second thread requires access to its PCI device, the proper address value is already located in the extension register.

Abstract translation: 多任务操作系统和方法更新扩展寄存器中的PCI地址值，以确保各种线程在访问外围PCI设备时使用正确的值。 当应用程序线程需要访问PCI设备时，操作系统将PCI设备地址的高位位写入两个位置：（1）PCI主桥的扩展寄存器，以允许PCI设备的即时寻址，以及（ 2）与线程相关联的单独内存位置。 当从第一个线程发生到第二个线程的上下文切换时，操作系统从与第二个线程相关联的存储器位置检索存储的值，并将该值写入扩展寄存器。 以这种方式，当第二线程需要访问其PCI设备时，适当的地址值已经位于扩展寄存器中。