X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fbootup.xml;h=65923528d4429d5046955ffc76873353fcbe7860;hp=e29c1a016796a0309e147fdf7a737e5ad874452e;hb=0d1aaec2282ee8e82908f9f12d820dab397adc0b;hpb=8284608198887230a1ac7f6ada9affeed3f437fb diff --git a/man/bootup.xml b/man/bootup.xml index e29c1a016..65923528d 100644 --- a/man/bootup.xml +++ b/man/bootup.xml @@ -44,7 +44,7 @@ bootup - The System Bootup Process + System bootup process @@ -53,7 +53,7 @@ A number of different components are involved in the system boot. Immediately after power-up, the system BIOS will do minimal hardware initialization, and hand - control over to a boot loader stored on a persistant + control over to a boot loader stored on a persistent storage device. This boot loader will then invoke an OS kernel from disk (or the network). In the Linux case this kernel now (optionally) extracts and @@ -111,7 +111,7 @@ target units are available, as listed on systemd.special7. - The follow chart is a structural overview of + The following chart is a structural overview of these well-known units and their position in the boot-up logic. The arrows describe which units are pulled in and ordered before which other units. Units @@ -147,18 +147,18 @@ v basic.target | - _________________/| emergency.service - / | | - | | v - v v emergency.target - (various system (various system - services services) - required for | - graphical UIs) v - | multi-user.target - | | - | _________________/ - |/ + __________________________________/| emergency.service + / | | | + | | | v + v v v emergency.target + display- (various system (various system + manager.service services services) + | required for | + | graphical UIs) v + | | multi-user.target + | | | + \_______________ | _________________/ + \|/ v graphical.target @@ -173,6 +173,77 @@ to them. + + Initrd System Manager Bootup + The default target in the initrd is the initrd.target. The bootup process is + identical to the System Manager Bootup until it reaches basic.target. From there, + systemd approaches the special initrd.target. If the root device can be mounted at + /sysroot, the sysroot.mount unit becomes active and the initrd-root-fs.target is + reached. + The initrd-parse-etc.service scans /sysroot/etc/fstab for a possible /usr mountpoint + and additional entries marked with the x-initrd.mount option. + All entries found are mounted below /sysroot, and the initrd-fs.target is reached. + The initrd-cleanup.service isolates to the initrd-switch-root.target, where cleanup + services can run. As the very last step, the initrd-switch-root.service is activated, + which will cause the system to switch its root to /sysroot. + + + + (identical to System Manager Bootup) + : + : + v + basic.target + | emergency.service + ______________________/| | + / | v + | sysroot.mount emergency.target + | | + | v + | initrd-root-fs.target + | | + | v + | initrd-parse-etc.service + (custom initrd services) | + | v + | (sysroot-usr.mount and + | various mounts marked + | with fstab option + | x-initrd.mount) + | | + | v + | initrd-fs.target + \______________________ | + \| + v + initrd.target + | + v + initrd-cleanup.service + isolates to + initrd-switch-root.target + | + v + ______________________/| + / | + | initrd-udevadm-cleanup-db.service + | | + (custom initrd services) | + | | + \______________________ | + \| + v + initrd-switch-root.target + | + v + initrd-switch-root.service + | + v + switch-root + + + + System Manager Shutdown @@ -219,7 +290,8 @@ systemd-reboot.service systemd-poweroff.service systemd-halt.service syste systemd1, boot7, systemd.special7, - systemd.target5 + systemd.target5, + dracut8