经典书籍翻译——深入理解Linux内核5

One more choice we had to make was the order to follow in studying Linux components. We tried a bottom-up approach: start with topics that are hardware-dependent and end with those that are totally hardware-independent. In fact, we’ll make many references to the 80×86 microprocessors in the first part of the book,while the rest of it is relatively hardware-independent. Significant exceptions are made in Chapter 13 and Chapter 14. In practice, following a bottom-up approach is not as simple as it looks, because the areas of memory management, processmanagement, and filesystems are intertwined; a few forward references—that is, references to topics yet to be explained—are unavoidable.Each chapter starts with a theoretical overview of the topics covered. The material is then presented according to the bottom-up approach. We start with the data structures needed to support the functionalities described in the chapter. Then we usually move from the lowest level of functions to higher levels, often ending by showing how system calls issued by user applications are supported.
我们所做的另一个最重要选择是按照怎样的顺序来组织接下来的Linux组件的学习：我们尝试了一种自底向上的方式——即从硬件相关的话题展开，逐步过渡到最终完全和硬件无关的内容。事实上，我们将在本书的第一部分多次涉及80X86的内容，而其他部分则很大程度上是独立于硬件的——这一点在第13章和14章会有例外情况。实际上要遵循这种“自底向上”的方式并不像看上去的这么简单，因为诸如内存管理、进程管理和文件系统这些领域往往是交织在一起的；同样的，引用少部分的具有前瞻性和争议性的文献也是不可避免的。本书的每个章节都是从所涵盖的理论概述开始，然后自底向上地阐述相关的材料。在各章节中，我们从支撑这些功能的数据结构开始，然后我们从最低级功能转向更高级功能，并最终以展现系统调用是如何支持应用程序结束的。