Bochs项目源码分析与注释.pdf

【实例简介】

开源虚拟机源码分析

【实例截图】

【核心代码】

Table of Content
Chapter 1 x86 体系结构与 PC 系统概要 .....................................1
1．1 x86 CPU 结构...............................................................................................................1
1．1．1 冯诺依曼架构和 CISC 指令集......................................................................1
1．1．2 CPU 结构........................................................................................................1
1．1．3 CPU 工作模式................................................................................................2
1．2 x86 体系结构概览........................................................................................................3
1．3 PC 系统.........................................................................................................................5
1．3．1 PC 系统概述...................................................................................................5
2．3．2 总线拓扑.........................................................................................................6
2．3．3 存储器与 I/O 编址 .........................................................................................6
2．3．4 关于系统的启动与引导.................................................................................8
Chapter 2 Bochs 工程概述....................................................... 11
2．1 开源项目 Bochs 介绍.................................................................................................11
2．2 版本 2.2.1 源码组织..................................................................................................11
2．3 工程类结构.................................................................................................................12
2．4 主体框架结构分析.....................................................................................................13
2．4．1 Bochs 工程中的重要类................................................................................13
（1） VM 控制台界面类 .............................................................................................13
（2） CPU 模拟............................................................................................................14
（3） Memory 模拟......................................................................................................14
（4）．I/O device 模拟...................................................................................................15
2．4．2 入口函数 main()及 Win32 Gui 初始化........................................................15
2．5 Bochs 的工作方式......................................................................................................18
Chapter 3 CPU 类的源码分析 ...................................................20
3．1 CPU 类概述................................................................................................................20
3．1．1 CPU 逻辑结构框图......................................................................................20
3．1．2 类 BX_CPU_C 成员归纳.............................................................................20
3．2 类 BX_CPU_C 源码分析..........................................................................................21
3．2．1 CPU 特性声明..............................................................................................21
3．2．2 类 bxInstruction_c 成员分析........................................................................22
3．2．3 类 BX_CPU_C 源码注释.............................................................................22
3．3 通用寄存器.................................................................................................................29
3．3．1 数据结构与注释...........................................................................................29
3．3．2 通用寄存器归纳...........................................................................................30
3．4 段寄存器、全局寄存器 GDI 和 IDT ........................................................................31
3．4．1 数据结构与注释...........................................................................................31
3．4．2 段寄存器结构分析.......................................................................................33
3．5 CPU 状态字 EFLAGS................................................................................................35
3．5．1 数据结构与注释...........................................................................................35 
Bochs 项目源码分析与注释 MAY 2006
Understanding the source code of bochs
3．5．2 源码分析.......................................................................................................39
3．6 函数 CPU_LOOP()结构分析.....................................................................................40
3．6．1 CPU_LOOP()函数总体结构........................................................................40
3．6．2 函数 CPU_LOOP()源码注释.......................................................................41
3．7 函数 handleAsyncEvent()分析...................................................................................44
3．7．1 函数 handleAsyncEvent()知识准备.............................................................44
3．7．2 函数 handleAsyncEvent()结构分析.............................................................46
3．7．3 函数 handleAsyncEvent()源码注释.............................................................47
3．8 取指与执行.................................................................................................................50
3．8．1 Intel IA-32 指令结构....................................................................................50
3．8．2 类 bxInstruction_c 的数据成员....................................................................53
3．8．3 取指译码函数 FetchDecode()分析 ..............................................................55
3．8．4 模拟指令的执行...........................................................................................59
Chapter 4 CPU 中断处理任务管理............................................60
4．1 IA-32 体系结构中断知识准备 ..................................................................................60
4．1．1 中断和异常概述...........................................................................................60
4．1．2 异常和中断向量...........................................................................................60
4．1．3 中断和异常来源...........................................................................................61
4．1．4 与中断处理相关的数据结构.......................................................................62
4．1．5 异常和中断的处理方法...............................................................................64
4．2 Bochs 对中断的模拟..................................................................................................68
4．2．1 概述...............................................................................................................68
4．2．2 主要函数的源码注释...................................................................................69
4．3 虚拟机的任务管理.....................................................................................................82
4．3．1 IA-32 任务管理知识准备 ...........................................................................82
4．3．2 函数 task_switch()源码注释 ........................................................................89
Chapter 5 存储器源码分析........................................................104
5．1 IA-32 体系的存储器结构 ........................................................................................104
5．2 Bochs 对存储器的模拟............................................................................................105
5．3 存储器类 BX_MEM_C 部分源码分析...................................................................107
5．3．1 相关数据结构与类定义.............................................................................107
5．3．2 相关函数分析.............................................................................................108
5．3 模拟分页机制...........................................................................................................115
5．3．1 分页 (Paging)概述.....................................................................................115
5．3．2 页目录与页表.............................................................................................116
5．3．3 线形地址转换.............................................................................................117
5．3．4 实现分页机制的源码分析.........................................................................120
Chapter 6 系统板与外设模拟 ..................................................136
6．1 Bochs 系统板描述类 bx_pc_system_c ...................................................................136
6．1．1 类 bx_pc_system_c 功能概述 ....................................................................136
6．1．2 PC system 定时器管理...............................................................................136 
Bochs 项目源码分析与注释 MAY 2006
Understanding the source code of bochs
6．1．3 类 bx_pc_system_c 源码分析与注释 ........................................................138
6．2 设备集合类 bx_devices_c........................................................................................146
6．2．1 类 bx_devices_c 成员变量分析.................................................................146
6．2．2 类 bx_devices_c 成员函数分析与注释 .....................................................149
6．2．3 设备的初始化.............................................................................................150
6．2．4 设备复位.....................................................................................................154
6．2．5 设备访问（读写）的处理.........................................................................155
6．2．6 已注册的 I/O handlers 和 IRQ 清单 ..........................................................159
6．3 定时器（PIT）类分析.............................................................................................166
6．3．1 类 bx_pit_c 概述.........................................................................................166
6．3．2 类 bx_pit_c 源码注释.................................................................................166
6．3．3 关于类 bx_virt_timer_c ..............................................................................173
6．4 IDE 设备...................................................................................................................173
6．4．1 磁盘控制器 controller_t .............................................................................173
6．4．2 IDE 驱动器描述类 bx_hard_drive_c .........................................................174
6．4．3 读写磁盘映象.............................................................................................175
6．4．4 ATA/IDE 控制器（通道）和设备初始化.................................................176
6．4．5 ATA 控制器的寄存器读写 ........................................................................184
6．4．6 CD ROM 设备............................................................................................193
6．5 PCI 子系统 ...............................................................................................................203
6．5．1 PCI 概述 .....................................................................................................203
6．5．2 PCI 主桥描述类 bx_pci_c 分析.................................................................209
6．6 VGA 设备模拟.........................................................................................................215
6．6．1 模拟 VGA 的类..........................................................................................215
6．6．2 VGA 在 svga_timer 中的更新 ...................................................................216
Appendix ...................................................................................217
Appendix A．Bochs 配置文本说明 ....................................................................................217
Appendix B．ATA 和 ATAPI 编程介绍.............................................................................225
Appendix C．Sound Blaster 16 编程...................................................................................230
Appendix D．VESA 编程介绍............................................................................................240
Appendix E．Bochs 上运行的操作系统示范.....................................................................261