需要前置 C 和 Linux 知识

• x86, bootstrap, kernel mode
• protection mode, multi process, process control, memory management, file system, io device control
• inter process communication, network
• virtualization, containerization, cluster

stages:

• get familiar with linux clis
• use glibc or syscall to write applications
• learn the kernel mechanism
• read kernel source code
• customize linux modules

# commands

system calls

# framework

# sys init

# x86

• 地址总线 (16, 32) 内存地址的范围
• 数据总线 - 每次最多能从内存取到多少数据

# bootstrap

ROM -> BIOS

# start kernel

• TASK_INIT(init_task)
  • process 0
• trap_init()
  • interrupts
• mm_init() - memory
• sched_init() - schedulers
• rest_init()
  • kernel_thread(kernel_init, NULL, CLONE_FS) - process 1
  • kernel_thread(kthreadd, NULL, CLONE_FS|CLONE_FILES) - process 2

four layers of process (execute permission) ring

• ring0 kernel mode
• ring3 user mode

# syscall of open

# process control

# memory control

# file system

# io system

# IPC

# network

# virtualization

# containerization

# practices

# references

• 趣谈 Linux 操作系统 - 极客时间