An embedded system is just a computer buried inside some other product. Surprisingly, you can know a great deal about programming and computing and still get lost in the arcane world of embedded systems. In the world of embedded systems programming, countless details — both hardware- and software-related — make the development process seem like a path that few have traveled and even fewer have survived. How do software, hardware, and firmware differ? How in the world does a 100,000-line program end up inside a device smaller than my fingernail? What is flash memory and why do I need a cache? What is the difference between a task and a process? Do I need to worry about reentrancy? As we progress through Embedded Systems Firmware Demystified, you will come to see that these questions are not as complex as they first appear. Embedded systems programming spans a wide range of activities from building programmable logic at the most concrete end to writing a UNIX™ process at the most abstract end. Bracketed by these poles, the industry has exploded in the last 20 years. In the late seventies, assemblers were considered luxuries. A typical embedded system used less than 64Kb of system memory (bits, not bytes!).

尽管本书关注的重点主要是固件仆发，但是一个好的阉件开发者必须对其所依 赖的硬件有很好的了解。人们可以将阂件编程者勺加油站换油的工作人员相比；如 果他所知迟的只是换油，那他就无论发现各种事故隐忠，而一个训练有素的技术t 人会今L发现这些迹象。受训不久的技术工人也许可以胜任换油的工作，但却不会 注意诺如盖垫密封片泄漏之类的问题。如果这些问题一直不被发现，则某些部件迟 早会出问题，片且b／能会由于技术工人的知识有限而产生额外的损失。 本各阐述度—个典型系统里，阑件]：程师需要了解关于硬件方面的知识。这 样做的目的并不是把你变成硬件设计右，而是为了佼你能做比“换油”更多的事 情。为了达到这个日的，本章讨论一些常见的cPu支持的外因设备并讨论处理器 如何完成工作。从讨论本书涉及的系统开始，你将了解现在基于微处理器系统的 一些最常见的特点，同时还将讨论cPu获得指令的步骤及使用缓存所引入的好处 和缺陷。 至本章的最后(尽管你还不是一名合格的硬件设计师)，你会对固件的硬件平 台有更好的现解。

Embedded Systems Firmware Demystified 嵌入式开发初学者很好的起步教材 写自己的操作系统

包含中文和英文内容对照；中文译文PDG格式。英文CHM格式。