这是一本专门为嵌入式读者打造的C语言进阶学习图书。本书的学习重点不再是C语言的基本语法，而是和嵌入式、C语言相关的一系列知识。作者以C语言为切入点，分别探讨了嵌入式开发所需要的诸多核心理论和技能，力图帮助读者从零搭建嵌入式开发所需要的完整知识体系和技能树。本书从底层CPU的制造流程和工作原理开始讲起，到计算机体系结构，C程序的反汇编分析，程序的编译、运行和重定位，程序运行时的堆栈内存动态变化，GNU C编译器的扩展语法，指针的灵活使用，C语言的面向对象编程思想，C语言的模块化编程思想，C语言的多任务编程思想，进程、线程和协程的概念，从底层到上层，从芯片、硬件到软件、框架，几乎涵盖了嵌入式开发的所有知识点。

王利涛，嵌入式工程师、培训讲师，多年嵌入式开发经验，包括芯片测试、BSP、驱动开发、USB子系统等。目前在开发《嵌入式工程师自我修养》系列在线视频教程，以及在个人博客（www.zhaixue.cc）分享更多的嵌入式、Linux、AIoT技术。

第1 章 工欲善其事，必先利其器 ·····································································.1
1.1 代码编辑工具：Vim ·············································································.2
1.1.1 安装Vim ·················································································.2
1.1.2 Vim 常用命令 ············································································.3
1.1.3 Vim 配置文件：vimrc ··································································.6
1.1.4 Vim 的按键映射 ·········································································.8
1.2 程序编译工具：make ···········································································.10
1.2.1 使用IDE 编译C 程序 ·································································.10
1.2.2 使用gcc 编译C 源程序 ·······························································.11
1.2.3 使用make 编译程序 ···································································.14
1.3 代码管理工具：Git ·············································································.16
1.3.1 什么是版本控制系统 ··································································.16
1.3.2 Git 的安装和配置 ······································································.18
1.3.3 Git 常用命令 ············································································.18
第2 章 计算机体系结构与CPU 工作原理 ·························································.21
2.1 一颗芯片是怎样诞生的 ········································································.22
2.1.1 从沙子到单晶硅 ········································································.22
2.1.2 PN 结的工作原理 ······································································.24
2.1.3 从PN 结到芯片电路 ···································································.26
2.1.4 芯片的封装 ··············································································.28
2.2 一颗CPU 是怎么设计出来的 ·································································.29
2.2.1 计算机理论基石：图灵机 ····························································.30
嵌入式C 语言自我修养——从芯片、编译器到操作系统
? XIV ?
2.2.2 CPU 内部结构及工作原理 ····························································.31
2.2.3 CPU 设计流程 ··········································································.33
2.3 计算机体系结构 ·················································································.37
2.3.1 冯·诺依曼架构 ··········································································.38
2.3.2 哈弗架构 ················································································.38
2.3.3 混合架构 ················································································.38
2.4 CPU 性能提升：Cache 机制 ···································································.39
2.4.1 Cache 的工作原理 ······································································.39
2.4.2 一级Cache 和二级Cache ·····························································.41
2.4.3 为什么有些处理器没有Cache ·······················································.42
2.5 CPU 性能提升：流水线 ········································································.42
2.5.1 流水线工作原理 ········································································.43
2.5.2 超流水线技术 ···········································································.44
2.5.3 流水线冒险 ··············································································.47
2.5.4 分支预测 ················································································.49
2.5.5 乱序执行 ················································································.50
2.5.6 SIMD 和NEON ········································································.51
2.5.7 单发射和多发射 ········································································.52
2.6 多核CPU ·························································································.54
2.6.1 单核处理器的瓶颈 ·····································································.54
2.6.2 片上多核互连技术 ·····································································.55
2.6.3 big.LITTLE 结构 ·······································································.58
2.6.4 超线程技术 ··············································································.59
2.6.5 CPU 核数越多越好吗 ··································································.61
2.7 后摩尔时代：异构计算的崛起 ································································.62
2.7.1 什么是异构计算 ········································································.62
2.7.2 GPU ······················································································.63
2.7.3 DSP ·······················································································.64
2.7.4 FPGA ·····················································································.64
2.7.5 TPU ·······················································································.65
2.7.6 NPU ······················································································.67
2.7.7 后摩尔时代的XPU 们 ·································································.70
目 录
? XV ?
2.8 总线与地址 ·······················································································.71
2.8.1 地址的本质 ··············································································.72
2.8.2 总线的概念 ··············································································.73
2.8.3 总线编址方式 ···········································································.74
2.9 指令集与微架构 ·················································································.74
2.9.1 什么是指令集 ···········································································.75
2.9.2 什么是微架构 ···········································································.76
2.9.3 指令助记符：汇编语言 ·······························································.79
第3 章 ARM 体系结构与汇编语言 ··································································.81
3.1 ARM 体系结构 ··················································································.81
3.2 ARM 汇编指令 ··················································································.84
3.2.1 存储访问指令 ···········································································.85
3.2.2 数据传送指令 ···········································································.87
3.2.3 算术逻辑运算指令 ·····································································.87
3.2.4 操作数：operand2 详解 ·······························································.88
3.2.5 比较指令 ················································································.88
3.2.6 条件执行指令 ···········································································.89
3.2.7 跳转指令 ················································································.90
3.3 ARM 寻址方式 ··················································································.91
3.3.1 寄存器寻址 ··············································································.91
3.3.2 立即数寻址 ··············································································.91
3.3.3 寄存器偏移寻址 ········································································.92
3.3.4 寄存器间接寻址 ········································································.92
3.3.5 基址寻址 ················································································.92
3.3.6 多寄存器寻址 ···········································································.92
3.3.7 相对寻址 ················································································.93
3.4 ARM 伪指令 ·····················································································.94
3.4.1 LDR 伪指令 ·············································································.94
3.4.2 ADR 伪指令 ·············································································.96
3.5 ARM 汇编程序设计·············································································.97
3.5.1 ARM 汇编程序格式 ···································································.97
嵌入式C 语言自我修养——从芯片、编译器到操作系统
? XVI ?
3.5.2 符号与标号 ··············································································.98
3.5.3 伪操作 ···················································································.99
3.6 C 语言和汇编语言混合编程 ·································································.101
3.6.1 ATPCS 规则 ···········································································.101
3.6.2 在C 程序中内嵌汇编代码 ··························································.103
3.6.3 在汇编程序中调用C 程序 ··························································.104
3.7 GNU ARM 汇编语言 ·········································································.105
3.7.1 重新认识编译器 ······································································.105
3.7.2 GNU ARM 编译器的伪操作 ························································.107
3.7.3 GNU ARM 汇编语言中的标号 ·····················································.108
3.7.4 .section 伪操作 ········································································.109
3.7.5 基本数据格式 ·········································································.110
3.7.6 数据定义 ··············································································.110
3.7.7 汇编代码分析实战 ···································································.111
第4 章 程序的编译、链接、安装和运行 ·························································.114
4.1 从源程序到二进制文件 ······································································.115
4.2 预处理过程 ·····················································································.120
4.3 程序的编译 ·····················································································.123
4.3.1 从C 文件到汇编文件 ································································.124
4.3.2 汇编过程 ··············································································.127
4.3.3 符号表与重定位表 ···································································.129
4.4 链接过程························································································.132
4.4.1 分段组装 ··············································································.132
4.4.2 符号决议 ··············································································.136
4.4.3 重定位 ·················································································.140
4.5 程序的安装 ·····················································································.142
4.5.1 程序安装的本质 ······································································.142
4.5.2 在Linux 下制作软件安装包 ························································.143
4.5.3 使用apt-get 在线安装软件 ··························································.145
4.5.4 在Windows 下制作软件安装包 ····················································.147
目 录
? XVII ?
4.6 程序的运行 ·····················································································.150
4.6.1 操作系统环境下的程序运行 ·······················································.150
4.6.2 裸机环境下的程序运行 ·····························································.153
4.6.3 程序入口main()函数分析 ···························································.154
4.6.4 BSS 段的小秘密 ······································································.157
4.7 链接静态库 ·····················································································.158
4.8 动态链接························································································.162
4.8.1 与地址无关的代码 ···································································.164
4.8.2 全局偏移表 ············································································.165
4.8.3 延迟绑定 ··············································································.166
4.8.4 共享库 ·················································································.168
4.9 插件的工作原理 ···············································································.169
4.10 Linux 内核模块运行机制 ···································································.171
4.11 Linux 内核编译和启动分析 ································································.174
4.12 U-boot 重定位分析 ··········································································.179
4.13 常用的binutils 工具集 ······································································.185
第5 章 内存堆栈管理 ·················································································.188
5.1 程序运行的“马甲”：进程 ·································································.189
5.2 Linux 环境下的内存管理 ····································································.190
5.3 栈的管理························································································.192
5.3.1 栈的初始化 ············································································.193
5.3.2 函数调用 ··············································································.195
5.3.3 参数传递 ··············································································.199
5.3.4 形参与实参 ············································································.201
5.3.5 栈与作用域 ············································································.206
5.3.6 栈溢出攻击原理 ······································································.208
5.4 堆内存管理 ·····················································································.210
5.4.1 裸机环境下的堆内存管理 ··························································.212
5.4.2 uC/OS 的堆内存管理 ································································.213
5.4.3 Linux 堆内存管理 ····································································.219
5.4.4 堆内存测试程序 ······································································.227
嵌入式C 语言自我修养——从芯片、编译器到操作系统
? XVIII ?
5.4.5 实现自己的堆管理器 ································································.229
5.5 mmap 映射区域探秘 ··········································································.233
5.5.1 将文件映射到内存 ···································································.236
5.5.2 mmap 映射实现机制分析 ···························································.239
5.5.3 把设备映射到内存 ···································································.240
5.5.4 多进程共享动态库 ···································································.243
5.6 内存泄漏与防范 ···············································································.245
5.6.1 一个内存泄漏的例子 ································································.245
5.6.2 预防内存泄漏 ·········································································.246
5.6.3 内存泄漏检测：MTrace ·····························································.248
5.6.4 广义上的内存泄漏 ···································································.250
5.7 常见的内存错误及检测 ······································································.251
5.7.1 总有一个Bug，让你泪流满面 ·····················································.253
5.7.2 使用core dump 调试段错误 ························································.254
5.7.3 什么是内存踩踏 ······································································.256
5.7.4 内存踩踏监测：mprotect ····························································.257
5.7.5 内存检测神器：Valgrind ····························································.259
第6 章 GNU C 编译器扩展语法精讲 ·····························································.263
6.1 C 语言标准和编译器 ·········································································.264
6.1.1 什么是C 语言标准 ··································································.264
6.1.2 C 语言标准的内容 ···································································.265
6.1.3 C 语言标准的发展过程 ·····························································.265
6.1.4 编译器对C 语言标准的支持 ·······················································.268
6.1.5 编译器对C 语言标准的扩展 ·······················································.268
6.2 指定初始化 ·····················································································.269
6.2.1 指定初始化数组元素 ································································.269
6.2.2 指定初始化结构体成员 ·····························································.271
6.2.3 Linux 内核驱动注册 ·································································.271
6.2.4 指定初始化的好处 ···································································.273
6.3 宏构造“利器”：语句表达式 ······························································.273
6.3.1 表达式、语句和代码块 ·····························································.273
目 录
? XIX ?
6.3.2 语句表达式 ············································································.274
6.3.3 在宏定义中使用语句表达式 ·······················································.276
6.3.4 内核中的语句表达式 ································································.280
6.4 typeof 与container_of 宏 ·····································································.280
6.4.1 typeof 关键字 ·········································································.280
6.4.2 typeof 使用示例 ······································································.281
6.4.3 Linux 内核中的container_of 宏 ····················································.281
6.4.4 container_of 宏实现分析 ····························································.283
6.5 零长度数组 ·····················································································.286
6.5.1 什么是零长度数组 ···································································.286
6.5.2 零长度数组使用示例 ································································.288
6.5.3 内核中的零长度数组 ································································.288
6.5.4 思考：指针与零长度数组 ··························································.290
6.6 属性声明：section·············································································.292
6.6.1 GNU C 编译器扩展关键字：__attribute__ ·······································.292
6.6.2 属性声明：section ···································································.294
6.6.3 U-boot 镜像自复制分析 ·····························································.297
6.7 属性声明：aligned ············································································.299
6.7.1 地址对齐：aligned ···································································.299
6.7.2 结构体的对齐 ·········································································.302
6.7.3 思考：编译器一定会按照aligned 指定的方式对齐吗 ·························.304
6.7.4 属性声明：packed ···································································.305
6.7.5 内核中的aligned、packed 声明 ····················································.306
6.8 属性声明：format ·············································································.306
6.8.1 变参函数的格式检查 ································································.306
6.8.2 变参函数的设计与实现 ·····························································.308
6.8.3 实现自己的日志打印函数 ··························································.312
6.9 属性声明：weak ···············································································.314
6.9.1 强符号和弱符号 ······································································.314
6.9.2 函数的强符号与弱符号 ·····························································.316
6.9.3 弱符号的用途 ·········································································.317
6.9.4 属性声明：alias ······································································.319
嵌入式C 语言自我修养——从芯片、编译器到操作系统
? XX ?
6.10 内联函数 ······················································································.320
6.10.1 属性声明：noinline ·································································.320
6.10.2 什么是内联函数 ····································································.320
6.10.3 内联函数与宏 ·······································································.321
6.10.4 编译器对内联函数的处理 ·························································.322
6.10.5 思考：内联函数为什么定义在头文件中 ········································.324
6.11 内建函数 ······················································································.324
6.11.1 什么是内建函数 ····································································.324
6.11.2 常用的内建函数 ····································································.325
6.11.3 C 标准库的内建函数 ·······························································.328
6.11.4 内建函数：__builtin_constant_p(n) ···············································.328
6.11.5 内建函数：__builtin_expect(exp,c) ···············································.329
6.11.6 Linux 内核中的likely 和unlikely ················································.330
6.12 可变参数宏 ···················································································.333
6.12.1 什么是可变参数宏 ··································································.334
6.12.2 继续改进我们的宏 ··································································.335
6.12.3 可变参数宏的另一种写法 ·························································.336
6.12.4 内核中的可变参数宏 ·······························································.336
第7 章 数据存储与指针 ··············································································.339
7.1 数据类型与存储 ···············································································.340
7.1.1 大端模式与小端模式 ································································.340
7.1.2 有符号数和无符号数 ································································.343
7.1.3 数据溢出 ··············································································.345
7.1.4 数据类型转换 ·········································································.348
7.2 数据对齐························································································.352
7.2.1 为什么要数据对齐 ···································································.352
7.2.2 结构体对齐 ············································································.353
7.2.3 联合体对齐 ············································································.356
7.3 数据的可移植性 ···············································································.358
7.4 Linux 内核中的size_t 类型 ··································································.360
7.5 为什么很多人编程时喜欢用typedef ·······················································.361
目 录
? XXI ?
7.5.1 typedef 的基本用法 ··································································.361
7.5.2 使用typedef 的优势 ··································································.364
7.5.3 使用typedef 需要注意的地方 ······················································.366
7.5.4 typedef 的作用域 ·····································································.368
7.5.5 如何避免typedef 被大量滥用 ······················································.368
7.6 枚举类型························································································.369
7.6.1 使用枚举的三种方法 ································································.370
7.6.2 枚举的本质 ············································································.370
7.6.3 Linux 内核中的枚举类型 ···························································.372
7.6.4 使用枚举需要注意的地方 ··························································.372
7.7 常量和变量 ·····················································································.373
7.7.1 变量的本质 ············································································.374
7.7.2 常量存储 ··············································································.376
7.7.3 常量折叠 ··············································································.377
7.8 从变量到指针 ··················································································.378
7.8.1 指针的本质 ············································································.379
7.8.2 一些复杂的指针声明 ································································.381
7.8.3 指针类型与运算 ······································································.383
7.9 指针与数组的“暧昧”关系 ·································································.386
7.9.1 下标运算符[] ··········································································.388
7.9.2 数组名的本质 ·········································································.389
7.9.3 指针数组与数组指针 ································································.392
7.10 指针与结构体 ················································································.395
7.11 二级指针 ······················································································.399
7.11.1 修改指针变量的值 ··································································.400
7.11.2 二维指针和指针数组 ·······························································.402
7.11.3 二级指针和二维数组 ·······························································.403
7.12 函数指针 ······················································································.407
7.13 重新认识void ················································································.408
第8 章 C 语言的面向对象编程思想 ·······························································.411
8.1 代码复用与分层思想 ·········································································.412
嵌入式C 语言自我修养——从芯片、编译器到操作系统
? XXII ?
8.2 面向对象编程基础 ············································································.413
8.2.1 什么是OOP ···········································································.414
8.2.2 类的封装与实例化 ···································································.414
8.2.3 继承与多态 ············································································.416
8.2.4 虚函数与纯虚函数 ···································································.418
8.3 Linux 内核中的OOP 思想：封装 ··························································.419
8.3.1 类的C 语言模拟实现 ································································.420
8.3.2 链表的抽象与封装 ···································································.422
8.3.3 设备管理模型 ·········································································.423
8.3.4 总线设备模型 ·········································································.427
8.4 Linux 内核中的OOP 思想：继承 ··························································.429
8.4.1 继承与私有指针 ······································································.429
8.4.2 继承与抽象类 ·········································································.430
8.4.3 继承与接口 ············································································.431
8.5 Linux 内核中的OOP 思想：多态 ··························································.433
第9 章 C 语言的模块化编程思想 ··································································.436
9.1 模块的编译和链接 ············································································.437
9.2 系统模块划分 ··················································································.439
9.2.1 模块划分方法 ·········································································.439
9.2.2 面向对象编程的思维陷阱 ··························································.441
9.2.3 规划合理的目录结构 ································································.442
9.3 一个模块的封装 ···············································································.443
9.4 头文件深度剖析 ···············································································.444
9.4.1 基本概念 ··············································································.444
9.4.2 隐式声明 ··············································································.446
9.4.3 变量的声明与定义 ···································································.447
9.4.4 如何区分定义和声明 ································································.449
9.4.5 前向引用和前向声明 ································································.450
9.4.6 定义与声明的一致性 ································································.453
9.4.7 头文件路径 ············································································.454
9.4.8 Linux 内核中的头文件 ······························································.456
目 录
? XXIII ?
9.4.9 头文件中的内联函数 ································································.459
9.5 模块设计原则 ··················································································.459
9.6 被误解的关键字：goto ·······································································.461
9.7 模块间通信 ·····················································································.462
9.7.1 全局变量 ··············································································.462
9.7.2 回调函数 ··············································································.466
9.7.3 异步通信 ··············································································.470
9.8 模块设计进阶 ··················································································.471
9.8.1 跨平台设计 ············································································.471
9.8.2 框架 ····················································································.473
9.9 AIoT 时代的模块化编程 ·····································································.476
第10 章 C 语言的多任务编程思想和操作系统入门 ···········································.478
10.1 多任务的裸机实现 ···········································································.479
10.1.1 多任务的模拟实现 ··································································.479
10.1.2 改变任务的执行频率 ·······························································.481
10.1.3 改变任务的执行时间 ·······························································.484
10.2 操作系统基本原理 ···········································································.488
10.2.1 调度器工作原理 ····································································.490
10.2.2 函数栈与进程栈 ····································································.492
10.2.3 可重入函数 ··········································································.493
10.2.4 临界区与临界资源 ··································································.495
10.3 中断 ····························································································.497
10.3.1 中断处理流程 ·······································································.497
10.3.2 进程栈与中断栈 ····································································.500
10.3.3 中断函数的实现 ····································································.504
10.4 系统调用 ······················································································.506
10.4.1 操作系统的API ·····································································.506
10.4.2 操作系统的权限管理 ·······························································.508
10.4.3 CPU 的特权模式 ····································································.508
10.4.4 Linux 系统调用接口 ································································.509
嵌入式C 语言自我修养——从芯片、编译器到操作系统
? XXIV ?
10.5 揭开文件系统的神秘面纱 ··································································.510
10.5.1 什么是文件系统 ····································································.511
10.5.2 文件系统的挂载 ····································································.513
10.5.3 根文件系统 ··········································································.514
10.6 存储器接口与映射 ···········································································.515
10.6.1 存储器与接口 ·······································································.515
10.6.2 存储映射 ·············································································.518
10.6.3 嵌入式启动方式 ····································································.520
10.7 内存与外部设备 ·············································································.521
10.7.1 内存与外存 ··········································································.521
10.7.2 外部设备 ·············································································.522
10.7.3 I/O 端口与I/O 内存 ································································.523
10.8 寄存器操作 ···················································································.524
10.8.1 位运算应用 ··········································································.524
10.8.2 操作寄存器 ··········································································.527
10.8.3 位域 ···················································································.529
10.9 内存管理单元MMU ········································································.531
10.9.1 地址转换 ·············································································.532
10.9.2 权限管理 ·············································································.534
10.10 进程、线程和协程 ·········································································.535
10.10.1 进程 ·················································································.536
10.10.2 线程 ·················································································.538
10.10.3 线程池 ··············································································.539
10.10.4 协程 ·················································································.540
10.10.5 小结 ·················································································.541
参考文献 ···································································································.543