系统启动过程中内核(/unix,/vmunix,/boot/zImage等)将加载至内存直到系统关机，在启动 过程中，init将扫描/etc/inittab,在此文件中将列出可用的终端及其属性，一旦找到活动 的终端，getty(mingetty,LINUX)会给出login提示符和口令，确认完成后将启动相应的 shell(/etc/passwd文件中用户的SHELL域)-boot process kernel (/ unix, / vmunix, / boot / zImage) to be loaded memory system shutdown until the start process, the init will scan / etc / inittab, this document will list of available terminals and attributes, once found the terminal , getty (mingetty and LINUX) will be given prompt and login passwords, recognizing completion, will start the corresponding shell (/ etc / passwd file users in the domain SHELL)