BOOTUP(7) bootup BOOTUP(7) NAME bootup - BIOS/UEFI //(GRUB2) /(Linux) Linux()initrd(initial RAM disk)( dracut(8) ) "rdinit="init( systemd(1)) "init="init( systemd(1)) init init ()initrd boot(7) "root=""init="init "" systemd(1) "init" systemd "" target ( systemd.target(5)) systemd default.target "" default.target graphical.target() multi-user.target() target systemd.special(7) target local-fs-pre.target | v ( mounts ( swap ( fsck services...) devices...) devices...) (: ( | | | udevd, tmpfiles, mounts: v v v random seed, mqueue, configfs, local-fs.target swap.target cryptsetup.target sysctl, ...) debugfs, ...) | | | | | \__________________|_________________ | ___________________|____________________/ \|/ v sysinit.target | ____________________________________/|\________________________________________ / | | | \ | | | | | v v | v v ( ( | ( rescue.service timers...) paths...) | sockets...) | | | | | v v v | v rescue.target timers.target paths.target | sockets.target . | | | . \_________________ | ___________________/ .................................... \|/ v basic.target | ____________________________________/| emergency.service / | | | | | | v v v v emergency.target display- ( () manager.service ) | | | | | | v | | multi-user.target | | | \_________________ | _________________/ \|/ v graphical.target (1) systemd.unit= ( systemd(1)) (2) default.target timers.target basic.target timer basic.target INITRD(INITIAL RAM DISK) initrd systemd init("rdinit=") initrd.target initrd basic.target initrd.target () initd-root-device.target /sysroot sysroot.mount initrd-root-fs.target initrd-parse-etc.service /sysroot/etc/fstab /usr () x-initrd.mount /sysroot initrd-fs.target initrd-cleanup.service systemctl --no-block isolate initrd-switch-root.target isolate () initrd-switch-root.service /sysroot () : v basic.target | emergency.service ______________________/| | / | v | initrd-root-device.target emergency.target | | | v | sysroot.mount | | | v | initrd-root-fs.target | | | v v initrd-parse-etc.service ( | initrd services...) v | (sysroot-usr.mount | fstab x-initrd.mount | ) | | | v | initrd-fs.target \______________________ | \| v initrd.target | v initrd-cleanup.service ( isolates initrd-switch-root.target) | v ______________________/| / v | initrd-udevadm-cleanup-db.service v | ( | initrd services...) | \______________________ | \| v initrd-switch-root.target | v initrd-switch-root.service | v systemd () ( mounts, swaps, cryptsetup devices ) | | v v shutdown.target umount.target | | \____________________________________ ______/ \ / v ( services) | v final.target | _____________________________________/ \_________________________________ / | | \ | | | | v v v v systemd-reboot.service systemd-poweroff.service systemd-halt.service systemd-kexec.service | | | | v v v v reboot.target poweroff.target halt.target kexec.target systemd(1), boot(7), systemd.special(7), systemd.target(5), dracut(8) man http://www.jinbuguo.com man https://github.com/man-pages-zh/manpages- zh systemd 231 BOOTUP(7)