Chapter 5 Memory Management 内存管理

The 80386 transforms logical addresses (i.e., addresses as viewed by programmers) into physical address (i.e., actual addresses in physical memory) in two steps:

80386通过两步将一个逻辑地址（程序所引用的地址）转移为物理地址（实际的物理内存地址）。

• Segment translation, in which a logical address (consisting of a segment selector and segment offset) are converted to a linear address.

段转换器，将一个逻辑地址（由段选择子和段偏移组成）被转换成线性地址。

• Page translation, in which a linear address is converted to a physical address. This step is optional, at the discretion of systems-software designers.

页转换器，将一个线性地址转换为物理地址。这一步是可选的，设系统软件的设计者而定。

These translations are performed in a way that is not visible to applications programmers. Figure 5-1 illustrates the two translations at a high level of abstraction.

在某种程度上，这些转换对于应用程序是不可见的。图5-1解释了两种转换在高层次上的抽象。

Figure 5-1 and the remainder of this chapter present a simplified view of the 80386 addressing mechanism. In reality, the addressing mechanism also includes memory protection features. For the sake of simplicity, however, the subject of protection is taken up in another chapter, Chapter 6.

图5-1和本章剩余部分展示了80386寻址一个简化的视图。实际上，寻址机制也包括内存保护特性。简化起见，保护方面的主题放在另一章，第16章。