hardware device driver

For example, when a driver communicates with hardware, it manipulates registers to request some desired operation of the device.

例如，在驱动程序与硬件进行通信时，它操纵寄存器以便请求一些所需的设备操作。

When the guest operating system's driver peeks and pokes at the memory and hardware registers, software exists underneath to emulate the device (see Figure 2).

在来宾操作系统的驱动程序窥探内存和硬件寄存器时，软件存在于下面来仿真设备（参见图 2）。

Suppose your device driver must be written from scratch, and you do not have the actual hardware while developing this device driver.

假设我们必须从头开始编写这个设备驱动程序，在开发这个设备驱动程序时还没有实际的硬件。