LINUX启动流程详解

LINUX-blog|[2010-6-215:08:05]2008-11-2711:04:06||(7)|(1)|(30264)linux,BIOS(MBR),MBR,,,,,.linuxLILOGRUB.,LILO.linux.Linux,linux.,./sbininit,initinitialization(),init/etc/inittab,.mingetty.,linux,,.,./sbininitinit,/sbininit.RedHatEnterpriseLinux:1.2.init()initinit---BIOS---------init---/etc/inittab---Runlevel---rc.sysinit---rc---mingetty---rc.local.BIOS,BIOS,PCLINUXBIOS0xFFFF0.BIOS,POST(PowerOnSelfTest),BIOS,,cpu,,;,,,,,,,.BIOS:POST.POST,,,BOIS,.BIOSBIOS,,(,CD-ROM,,,USB),linuxMBR(masterbootrecord,,001),512446(44664416,MBR0xAA55,MBR,MBRRAM,BIOSMBR),grub.(grublilo,ext2ext3LINUX).MBR#/dev/sda512mbr.bin[root@localhost~]#ddif=/dev/sdaof=mbr.binbs=512count=1#ASCII[root@localhostpam.d]#od-xambr.bingrub:/boot/grub/grub.conf,,.LINUX-blog|[2010-6-215:08:05]cat/boot/grub/grub.conf,defaule=0,defaule=1titletitleroot(hd0,0)hd000defaule=0timeout5GRUB5defaulesplashimagehd00/grub/splash.xpm.gzhiddenmenutitleroot(hd0,0):0(hd0,0)/bootkernel:(hd0,0)/bootbootrorootLABEL/roreadonly,rhgbredhatrhgbquitequiteinitrdinitrd.,.BIOSLinux/etc/bin/sbin/dev/libLinuxgrub“rorootLABEL/”LinuxLINUX,,zlmage(,512kb)bzlmage(512kb),zlib.RAMLINUX-blog|[2010-6-215:08:05]bzlmage,(i386),./arch/i386/boot/head.Sstart,,./arch/i386/boot/compressed/headSstartup_32,(),BlockStartedbySymbol(BSS),decompress_kernelC(./arch/i386/boot/compressed/misc.c).,.startup_32,./arch/i386/kernel/head.S.startup_32(0),,.(FPU)CPU,,start_kernel(init/main.c),Linux.,Linuxmain.start_kernel,,,RAM.,kernel_thread(arch/i386/kernel/process.c)init,(user-spaceprocess).,,(cpu_idle).,,.,RAM(initrd)2,RAM.initrdRAM,.initrd,,.,(pivot_root),initrd,,initrdlinux,,,,,initrd,.,initrd,(NFS).GRUBinitrd:grubkernel/bzImage-2.6.14.2[Linux-bzImage,setup=0x1400,size=0x29672e]grubinitrd/initrd-2.6.14.2.img[Linux-initrd@0x5f13000,0xcc199bytes]grubbootUncompressingLinux...Ok,bootingthekernel./Tabinitrdgruba)/sbin/grub-md5-cryptgrub[root@localhostpam.d]#/sbin/grub-md5-cryptPassword:Retypepassword:$1$3YbPF$zFVRY6J8VxNR9Ok4fXRkr1b)/etc/grub.confpassword--md5$1$3YbPF$zFVRY6J8VxNR9Ok4fXRkr1titlegrubgrubep..initKernelinitinitLinuxPID1RedHatEnterpriseLinuxRunLevelinitinit,init,Linuxinit.initinitinitLINUX-blog|[2010-6-215:08:05]initinitinit/etc/inittabinitLinuxLinuxinit/etc/inittab,cat/etc/inittabinit,1.runlevelLinuxinitrunlevel067runlevel067runlevel0initdefaultid:5:initdefaulerunlevel1Singleusermoderootrunlevel2NFSworkingrunlevel3runlevel2runlevel4runlevel3runlevel5runlevel3runlevel6runlevel6initdefault135runlevelinitrunlevel,init3init6init0id:5:initdefault:runlevel52.initsi::sysinit:/etc/rc.d/rc.sysinit/etc/rc.d/rc.sysinit(sysinit)rc.sysinitinitrc.sysinit/etc/rc.d/rc.sysinit:$PATHhostname/etc/sysconfig/networkLINUX-blog|[2010-6-215:08:05]rootrootroot/root/etc/mtabrootmtab/etc/mtab/etc/fastboot/etc/nologinUUCPlockpid3.runlevelrcrc.sysinitinit/etc/rc.d/rc,/etc/rc.drcX.d,X/etc/rc.d/init.dls-l/etc/rc.drunlevel,runlevel5rc5.d.ls-l/etc/rc.d/rc5.d,,:KSKKillSStartKS;;.,5initinittabl5:5:wait:/etc/rc.d/rc55,5/etc/rc.d/rc,init(wait)5/etc/rc.d/rc/etc/rc.d/rcshell5/etc/rc.d/rc5.d/rc/etc/rc.d/rc5.d/LINUX-blog|[2010-6-215:08:05](/init.d,)rcrc/etc/rc.d/init.d/rcstartstoprestartstatus/etc/rc.d/rc5.d/rcKSSstartK/var/lock/subsys/stopinitchkconfigamdNFSapmdarpwatchLANIPautofsautomountNFSNIScrondLinuxnamedDNSnetfsNFSSambaNetWarenetworknfsNFSportmapRPCportmapRPCsendmailsendmailsmbSamba/syslogsyslogklogdxfsXWindowXXinetdwuftpsshdtelnetrcinit4.ca::ctrlaltdel:/sbin/shutdown-t3-rnowcrtl+alt+delshutdown-t3-rnow()5.UPSpf::powerfail:/sbin/shutdown-f-h+2PowerRestored;ShutdownCancelledUPSshutdown-f-h+2shutdown-cUPSlinuxUPSUPSLinuxUPSlinuxUPSUPSLINUX-blog|[2010-6-215:08:05]6.6tty1tty6#Rungettysinstandardrunlevels1:12345:respawn:/sbin/minggettytty12:2345:respawn:/sbin/minggettytty23:2345:respawn:/sbin/minggettytty34:2345:respawn:/sbin/minggettytty45:2345:respawn:/sbin/minggettytty56:2345:respawn:/sbin/minggettytty6mingettytty1tty662.3.4.5ttyX/sbin/mingetty,ttyX,mingetty(respawn)7.runlevel5XWindows#Runxdminrunlevel5x:5:respawn:/usr/bin/X11/xdm-nodaemon5xdm,xdm,(respawn),/etc/X11/prefdm-nodemonXWindows./etc/ec.d/rc.local(s99local-../rc.local)s99RHEL4235RunLevel,/etc/rc.d/rc.localLinux/etc/rc.d/rc.local../bin/loginloginshellloginmingettyloginroot/etc/nologinloginnologinroot/etc/securettyrootroot/etc/userttylogin/etc/passwd/etc/shadowshellshellshell/bin/bashlogin/var/log/lastlog/usr/spool/mail/bash/etc/profile.bash_profileLINUX-blog|[2010-6-215:08:05]