1 TI-Sitara(AM335x-SK)
AM335x-SK, Start Kit 관련하여 File system을 간단히 분석을 해보고, 이를 최적화를 하려고 한다.
분석을 해보면, /sbin/init 을 systemd로 이용하고 SysVinit의 bootscript 을 혼용해서 사용하고 있다.
TI의 경우는 변화 도중 인지 몰라도 /lib/systemd/systemd boot 후 SysVInit Script모드를 사용한다.
현재의 추세가 SysVInit 에서 systemd로 변환되어지는 구조이며, 혼용해서 사용하는 독특한 구조이다.
Systemd 와 SysVInit 혼용
https://ahyuo79.blogspot.com/2017/04/linux-init-script.html
1.1 기본동작분석
boot parameter 확인하고, file system의 구조를 파악을 하자
Kernel은 Filesystem이 존재하지 않으면 Booting이 되지 않기때문에 아래의 두개의 중요
- root= filesystem
- init= init program ( 현재 설정하지 않았기 때문에 기본설정 /sbin/init)
root@am335x-evm:~# cat /proc/cmdline
console=ttyO0,115200n8 root=PARTUUID=000390f5-02 rw rootfstype=ext4 rootwait
root@am335x-evm:~# cat /proc/1/cmdline // init args 확인
root@am335x-evm:~# ls /proc/1/fd // 관련 FD 확인 부모 Process / 자식 Process
or
root@am335x-evm:~# ls /proc/1/fdinfo
상위 커널 Argument를 보면 현재 /sbin/init로 기반으로 동작
/sbin/init -> /lib/systemd/systemd (현재 /sbin/init 은 /lib/systemd/systemd에 link)
- /sin/init 와 runlevel 존재 확인
root@am335x-evm:~# ls /sbin
agetty e2fsck fsck.minix ifup losetup mkswap.util-linux route switch_root.util-linux
arp e2image fsck.minix.util-linux init losetup.util-linux modinfo routef sysctl
badblocks e2label fsck.msdos insmod lsmod modinfo.kmod routel sysctl.procps
blkid e2undo fsck.util-linux insmod.kmod mkdosfs modprobe rtmon syslogd
blockdev e4crypt fsck.vfat ip mke2fs modprobe.kmod rtpr tc
blockdev.util-linux e4defrag fstrim ip.iproute2 mkfs.ext2 mount-copybind runlevel tune2fs
bridge fatlabel fw_printenv iwconfig mkfs.ext3 mount.nfs setconsole udevd
cfdisk fdisk fw_setenv iwgetid mkfs.ext4 mount.nfs4 shutdown udhcpc
ctrlaltdel fdisk.util-linux getty iwlist mkfs.ext4dev nologin start-stop-daemon uevent
debugfs filefrag halt iwpriv mkfs.fat pivot_root sulogin umount.nfs
depmod fsck hdparm iwspy mkfs.minix pivot_root.util-linux sulogin.util-linux umount.nfs4
depmod.kmod fsck.ext2 hdparm.hdparm klogd mkfs.minix.util-linux populate-extfs.sh swapoff vconfig
dosfsck fsck.ext3 hwclock ldconfig mkfs.msdos poweroff swapoff.util-linux vigr
dosfslabel fsck.ext4 ifcfg loadkmap mkfs.vfat reboot swapon vigr.shadow
dumpe2fs fsck.ext4dev ifconfig logread mklost+found rmmod swapon.util-linux vipw
e2freefrag fsck.fat ifdown logsave mkswap rmmod.kmod switch_root vipw.shadow
- runlevel 0~6까지 존재하며, init를 통해 다시 확인가능
- init 0 : Halt
- init 1 : Single-user Mode
- init 2 : Multi-user Mode (Not support network)
- init 3 : Multi-user Mode with Networking
- init 4 : Not used/User-definable (For special purposes)
- init 5 : Graphic-user Mode ( As runlevel 3 + display manager)
- init 6 : Reboot (Reboots the system)
https://wiki.kldp.org/KoreanDoc/html/Boot_Process-KLDP/iterateinittab.html
- systemd 관련 명령어 (system damon)
systemd 명령어와 관련 명령어 검색
root@am335x-evm:~# find / -name systemd
/var/lib/systemd
/lib/systemd
/lib/systemd/systemd // 실제 user를 위한 system daemon 이며 이동작을 확인 (systemctl)
/etc/systemd
/etc/xdg/systemd
/sys/fs/cgroup/systemd
/run/user/0/systemd
/run/udev/tags/systemd
/run/systemd
/usr/lib/systemd
/usr/share/systemd
/usr/include/systemd
/tmp/0-runtime-dir/systemd
다양한 systemd의 실행이며 각각의 역할이 있으며, 이 부분은 좀 더 자세히 알아보자
root@am335x-evm:~# ls /lib/systemd/
network systemd-ac-power systemd-initctl systemd-networkd-wait-online systemd-shutdown systemd-udevd
system systemd-backlight systemd-journald systemd-quotacheck systemd-sleep systemd-update-done
system-generators systemd-bootchart systemd-localed systemd-random-seed systemd-socket-proxyd systemd-update-utmp
system-preset systemd-cgroups-agent systemd-logind systemd-remount-fs systemd-sysctl systemd-user-sessions
system-shutdown systemd-fsck systemd-machined systemd-reply-password systemd-sysv-install systemd-vconsole-setup
system-sleep systemd-hibernate-resume systemd-modules-load systemd-resolved systemd-timedated
systemd systemd-hostnamed systemd-networkd systemd-rfkill systemd-timesyncd
root@am335x-evm:~# /lib/systemd/systemd --help
systemd [OPTIONS...]
Starts up and maintains the system or user services.
-h --help Show this help
--test Determine startup sequence, dump it and exit
--no-pager Do not pipe output into a pager
--dump-configuration-items Dump understood unit configuration items
--unit=UNIT Set default unit
--system Run a system instance, even if PID != 1
--user Run a user instance
--dump-core[=BOOL] Dump core on crash
--crash-vt=NR Change to specified VT on crash
--crash-reboot[=BOOL] Reboot on crash
--crash-shell[=BOOL] Run shell on crash
--confirm-spawn[=BOOL] Ask for confirmation when spawning processes
--show-status[=BOOL] Show status updates on the console during bootup
--log-target=TARGET Set log target (console, journal, kmsg, journal-or-kmsg, null)
--log-level=LEVEL Set log level (debug, info, notice, warning, err, crit, alert, emerg)
--log-color[=BOOL] Highlight important log messages
--log-location[=BOOL] Include code location in log messages
--default-standard-output= Set default standard output for services
--default-standard-error= Set default standard error output for services
systemd의 설명
https://www.freedesktop.org/software/systemd/man/systemd.html#
- systemd의 설정 (system/user 설정 값확인)
- /etc/systemd/system.conf
- /etc/systemd/user.conf
https://www.freedesktop.org/software/systemd/man/systemd-system.conf.html#
1.2 systemd-x program들
각 systemd-xxx program 설치는 옵션이므로, 대부분 필요한 것들을 별도설치
root@am335x-evm:~# ls -al /usr/bin/systemd-*
-rwxr-xr-x 1 root root 26160 Dec 15 00:09 /usr/bin/systemd-cat
-rwxr-xr-x 1 root root 256116 Dec 15 00:09 /usr/bin/systemd-cgls
-rwxr-xr-x 1 root root 268436 Dec 15 00:09 /usr/bin/systemd-cgtop
-rwxr-xr-x 1 root root 54932 Dec 15 00:09 /usr/bin/systemd-delta
-rwxr-xr-x 1 root root 30256 Dec 15 00:09 /usr/bin/systemd-detect-virt
-rwxr-xr-x 1 root root 535036 Dec 15 00:09 /usr/bin/systemd-nspawn
-rwxr-xr-x 1 root root 34348 Dec 15 00:09 /usr/bin/systemd-path
-rwxr-xr-x 1 root root 292980 Dec 15 00:09 /usr/bin/systemd-resolve
-rwxr-xr-x 1 root root 334168 Dec 15 00:09 /usr/bin/systemd-run
-rwxr-xr-x 1 root root 46672 Dec 15 00:09 /usr/bin/systemd-socket-activate
-rwxr-xr-x 1 root root 239724 Dec 15 00:09 /usr/bin/systemd-stdio-bridge
...
systemd-cat
https://www.freedesktop.org/software/systemd/man/systemd-cat.html#
systemd-cgls
https://www.freedesktop.org/software/systemd/man/systemd-cgls.html#
systemd-cgtop
https://www.freedesktop.org/software/systemd/man/systemd-cgtop.html#
systemd-run
https://www.freedesktop.org/software/systemd/man/systemd-run.html
systemd-nspanwn
https://www.freedesktop.org/software/systemd/man/systemd-nspawn.html
systemd-xxx 검색
https://www.freedesktop.org/software/systemd/man/index.html
systemd-analyze가 없음 (추후 설치)
https://www.freedesktop.org/software/systemd/man/systemd-analyze.html
systemd의 service 등록방법
https://chhanz.github.io/linux/2019/01/18/linux-how-to-create-custom-systemd-service/
https://fmd1225.tistory.com/93
systemd의 Yocto service 등록방법
https://community.nxp.com/thread/472820
systemd-analyze 못찾을 경우
https://stackoverflow.com/questions/34501611/systemd-apparently-not-finding-service-file
backup
https://stackoverflow.com/questions/50354012/systemctl-failing-with-unknown-section-timer
1.3 Process 의 PID 분석
Process의 PID를 보고 현재 실행되는 순서를 역분석을 해보면, 아래와 같이 /sbin/init 가 PID가 1 지만, link만 존재하므로 systemd가 실행이 되어있다.
확인할 경우 아래와 같이
ps -ax or
ps -aux 전체사항을 확인하고 필요한 사항이 있다면,
grep or
head or
tail 사용하자.
root@am335x-evm:~# ps -aux
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 1 9.9 1.7 5232 4384 ? Ss 23:15 0:08 /sbin/init
root 2 0.0 0.0 0 0 ? S 23:15 0:00 [kthreadd]
root 3 0.1 0.0 0 0 ? S 23:15 0:00 [ksoftirqd/0]
root 4 0.0 0.0 0 0 ? S 23:15 0:00 [kworker/0:0]
root 5 0.0 0.0 0 0 ? S< 23:15 0:00 [kworker/0:0H]
root 6 0.0 0.0 0 0 ? S 23:15 0:00 [kworker/u2:0]
root 7 0.2 0.0 0 0 ? S 23:15 0:00 [rcu_preempt]
root 8 0.0 0.0 0 0 ? S 23:15 0:00 [rcu_sched]
root 9 0.0 0.0 0 0 ? S 23:15 0:00 [rcu_bh]
root 10 0.0 0.0 0 0 ? S 23:15 0:00 [kdevtmpfs]
root 11 0.0 0.0 0 0 ? S< 23:15 0:00 [netns]
root 12 0.0 0.0 0 0 ? S< 23:15 0:00 [perf]
root 13 0.0 0.0 0 0 ? S 23:15 0:00 [kworker/0:1]
root 14 0.0 0.0 0 0 ? S< 23:15 0:00 [writeback]
root 15 0.0 0.0 0 0 ? S< 23:15 0:00 [crypto]
root 16 0.0 0.0 0 0 ? S< 23:15 0:00 [bioset]
root 17 0.0 0.0 0 0 ? S< 23:15 0:00 [kblockd]
root 18 0.0 0.0 0 0 ? S< 23:15 0:00 [edac-poller]
root 19 0.0 0.0 0 0 ? S< 23:15 0:00 [rpciod]
root 20 0.0 0.0 0 0 ? S 23:15 0:00 [kswapd0]
root 21 0.0 0.0 0 0 ? S 23:15 0:00 [fsnotify_mark]
root 22 0.0 0.0 0 0 ? S< 23:15 0:00 [nfsiod]
root 31 0.0 0.0 0 0 ? S< 23:15 0:00 [dma_wq]
root 32 0.7 0.0 0 0 ? S 23:15 0:00 [kworker/u2:1]
root 33 0.0 0.0 0 0 ? S< 23:15 0:00 [bioset]
root 34 0.0 0.0 0 0 ? S< 23:15 0:00 [bioset]
root 35 0.0 0.0 0 0 ? S< 23:15 0:00 [bioset]
root 36 0.0 0.0 0 0 ? S< 23:15 0:00 [bioset]
root 37 0.0 0.0 0 0 ? S< 23:15 0:00 [bioset]
root 38 0.0 0.0 0 0 ? S< 23:15 0:00 [bioset]
root 39 0.0 0.0 0 0 ? S< 23:15 0:00 [bioset]
root 40 0.0 0.0 0 0 ? S< 23:15 0:00 [bioset]
root 43 0.0 0.0 0 0 ? S< 23:15 0:00 [kpsmoused]
root 44 0.0 0.0 0 0 ? S 23:15 0:00 [irq/180-4803c00]
root 45 0.0 0.0 0 0 ? S 23:15 0:00 [irq/179-4803c00]
root 46 0.0 0.0 0 0 ? S< 23:15 0:00 [ipv6_addrconf]
root 47 0.0 0.0 0 0 ? S< 23:15 0:00 [deferwq]
root 48 0.0 0.0 0 0 ? S 23:15 0:00 [irq/159-44e0b00]
root 49 0.1 0.0 0 0 ? S 23:15 0:00 [kworker/u2:2]
root 50 0.0 0.0 0 0 ? S 23:15 0:00 [irq/33-48060000]
root 51 0.0 0.0 0 0 ? S 23:15 0:00 [kworker/u2:3]
root 52 0.0 0.0 0 0 ? S< 23:15 0:00 [bioset]
root 53 1.6 0.0 0 0 ? S 23:15 0:01 [mmcqd/0]
root 54 0.1 0.0 0 0 ? S< 23:15 0:00 [kworker/0:1H]
root 55 0.0 0.0 0 0 ? S 23:15 0:00 [jbd2/mmcblk0p2-]
root 56 0.0 0.0 0 0 ? S< 23:15 0:00 [ext4-rsv-conver]
root 68 0.0 0.0 0 0 ? S 23:15 0:00 [kworker/0:2]
root 76 0.0 0.0 0 0 ? S< 23:15 0:00 [cryptodev_queue]
root 98 2.3 0.7 3616 1908 ? Ss 23:15 0:01 /lib/systemd/systemd-journald // log를 위해 시작
root 121 0.1 0.0 0 0 ? S 23:15 0:00 [kworker/0:3]
root 127 1.6 1.0 10524 2528 ? Ss 23:15 0:01 /lib/systemd/systemd-udevd //udevd 시작
root 325 0.0 0.0 0 0 ? S< 23:15 0:00 [pvr_timer]
systemd+ 398 0.2 0.6 12136 1608 ? Ssl 23:15 0:00 /lib/systemd/systemd-timesyncd
root 432 0.0 0.0 0 0 ? S 23:15 0:00 [irq/195-remotep]
root 437 0.0 0.0 0 0 ? S 23:15 0:00 [irq/197-remotep]
root 456 0.0 0.0 0 0 ? S 23:15 0:00 [scsi_eh_0]
root 457 0.0 0.0 0 0 ? S< 23:15 0:00 [scsi_tmf_0]
root 458 0.0 0.0 0 0 ? S 23:15 0:00 [usb-storage]
root 460 0.0 0.5 1956 1300 ? Ss 23:15 0:00 /sbin/klogd -n
root 469 2.5 2.5 8864 6408 ? Ss 23:15 0:01 /usr/sbin/ofonod -n
root 471 0.1 0.7 2600 1812 ? Ss 23:15 0:00 /lib/systemd/systemd-logind
root 475 0.1 0.5 1908 1440 ? Ss 23:15 0:00 /usr/libexec/ipsec/starter --daemon charon --nofork
root 480 0.1 0.4 1972 1244 ? Ss 23:15 0:00 /sbin/syslogd -n -C
avahi 483 0.0 0.9 4660 2484 ? Ss 23:15 0:00 avahi-daemon: running [am335x-evm.local]
message+ 492 0.5 0.9 4320 2496 ? Ss 23:15 0:00 /usr/bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-activation
root 494 0.0 0.0 0 0 ? S< 23:15 0:00 [bioset]
avahi 501 0.0 0.7 4660 1792 ? S 23:15 0:00 avahi-daemon: chroot helper
root 513 0.0 0.0 0 0 ? S 23:15 0:00 [file-storage]
systemd+ 535 0.2 0.8 2776 2056 ? Ss 23:15 0:00 /lib/systemd/systemd-networkd
root 562 0.2 1.8 142008 4528 ? Ssl 23:15 0:00 /usr/libexec/ipsec/charon
systemd+ 677 0.0 0.7 2984 1904 ? Ss 23:15 0:00 /lib/systemd/systemd-resolved
root 682 0.0 0.4 1780 1184 tty1 Ss+ 23:15 0:00 /sbin/agetty --noclear tty1 linux
root 688 0.1 0.8 4864 2132 ttyS0 Ss 23:15 0:00 /bin/login --
root 689 0.0 0.4 1780 1196 ttyGS0 Ss+ 23:15 0:00 /sbin/agetty -8 -L ttyGS0 115200 xterm
root 691 0.2 1.1 5160 2984 ? Ss 23:15 0:00 /usr/sbin/lighttpd -D -f /etc/lighttpd.conf
root 773 0.0 0.0 0 0 ? S< 23:15 0:00 [pvr_workqueue]
root 807 0.0 0.7 2664 1776 tty4 Ss+ 23:15 0:00 /bin/sh /usr/bin/runWeston
root 810 0.5 5.0 19144 12556 tty4 S+ 23:15 0:00 weston --idle-time=0
root 815 0.0 0.3 1956 868 ? Ss 23:15 0:00 /usr/sbin/telnetd
root 822 0.2 2.0 7008 5096 tty4 S+ 23:15 0:00 /usr/libexec/weston-keyboard
root 823 0.2 2.0 7016 5024 tty4 S+ 23:15 0:00 /usr/libexec/weston-desktop-shell
nobody 829 0.0 0.6 2448 1632 ? Ss 23:15 0:00 /usr/sbin/thttpd -d /srv/www -p 8080
root 835 0.0 0.3 2292 928 ? Ss 23:15 0:00 /usr/sbin/rngd -r /dev/urandom
root 843 8.3 24.3 176048 60924 ? Sl 23:15 0:04 /usr/bin/matrix_browser http://localhost:80/
root 860 0.0 0.0 0 0 ? S 23:15 0:00 [kworker/0:4]
root 863 0.0 0.0 0 0 ? S 23:15 0:00 [kworker/0:5]
root 867 0.4 0.0 0 0 ? S 23:15 0:00 [kworker/0:6]
root 894 1.3 1.7 5348 4388 ? Ss 23:15 0:00 /lib/systemd/systemd --user //user용 systemd 실행 (일반서비스)
root 898 0.0 0.9 7492 2352 ? S 23:15 0:00 (sd-pam)
root 901 0.0 0.8 2668 2044 ttyS0 S 23:15 0:00 -sh
root 918 0.2 0.4 1780 1212 ? Ss 23:16 0:00 /sbin/agetty -8 -L ttyS3 115200 xterm
root 922 0.0 0.5 2612 1272 ttyS0 R+ 23:16 0:00 ps -aux
2 systemd 와 init script 혼합 (telinit)
/sbin/telinit 확인필요
- run level 3 확인 (init.d link)
root@am335x-evm:~# runlevel
N 3 // multi-user mode
root@am335x-evm:/etc# ls -al rc3.d // Runlevel 3 분석
drwxr-xr-x 2 root root 4096 Dec 15 2016 .
drwxr-xr-x 46 root root 4096 Dec 14 23:15 ..
lrwxrwxrwx 1 root root 20 Dec 15 2016 S01networking -> ../init.d/networking
lrwxrwxrwx 1 root root 16 Dec 15 2016 S02dbus-1 -> ../init.d/dbus-1
lrwxrwxrwx 1 root root 19 Dec 15 2016 S03uim-sysfs -> ../init.d/uim-sysfs
lrwxrwxrwx 1 root root 16 Dec 15 2016 S08rc.pvr -> ../init.d/rc.pvr
lrwxrwxrwx 1 root root 18 Dec 15 2016 S10dropbear -> ../init.d/dropbear
lrwxrwxrwx 1 root root 17 Dec 15 2016 S10telnetd -> ../init.d/telnetd
lrwxrwxrwx 1 root root 17 Dec 15 2016 S12rpcbind -> ../init.d/rpcbind
lrwxrwxrwx 1 root root 21 Dec 14 23:36 S15mountnfs.sh -> ../init.d/mountnfs.sh
lrwxrwxrwx 1 root root 19 Dec 15 2016 S19nfscommon -> ../init.d/nfscommon
lrwxrwxrwx 1 root root 24 Dec 15 2016 S20busybox-udhcpd -> ../init.d/busybox-udhcpd
lrwxrwxrwx 1 root root 20 Dec 15 2016 S20hwclock.sh -> ../init.d/hwclock.sh
lrwxrwxrwx 1 root root 16 Dec 15 2016 S20syslog -> ../init.d/syslog
lrwxrwxrwx 1 root root 16 Dec 15 2016 S20thttpd -> ../init.d/thttpd
lrwxrwxrwx 1 root root 22 Dec 15 2016 S21avahi-daemon -> ../init.d/avahi-daemon
lrwxrwxrwx 1 root root 15 Dec 15 2016 S22ofono -> ../init.d/ofono
lrwxrwxrwx 1 root root 19 Dec 15 2016 S30rng-tools -> ../init.d/rng-tools
lrwxrwxrwx 1 root root 18 Dec 15 2016 S70lighttpd -> ../init.d/lighttpd
lrwxrwxrwx 1 root root 24 Dec 15 2016 S97matrix-gui-2.0 -> ../init.d/matrix-gui-2.0
lrwxrwxrwx 1 root root 18 Dec 15 2016 S98parse-ip -> ../init.d/parse-ip
lrwxrwxrwx 1 root root 27 Dec 15 2016 S98thermal-zone-init -> ../init.d/thermal-zone-init
lrwxrwxrwx 1 root root 22 Dec 15 2016 S99gplv3-notice -> ../init.d/gplv3-notice
lrwxrwxrwx 1 root root 22 Dec 14 23:36 S99rmnologin.sh -> ../init.d/rmnologin.sh
root@am335x-evm:/etc# ls -al init.d/
drwxr-xr-x 2 root root 4096 Dec 15 2016 .
drwxr-xr-x 46 root root 4096 Dec 14 23:15 ..
-rw-r--r-- 1 root root 1150 Dec 15 00:09 README
-rwxr-xr-x 1 root root 250 Dec 14 23:23 alignment.sh
-rwxr-xr-x 1 root root 811 Dec 14 23:45 alsa-state
-rwxr-xr-x 1 root root 4491 Dec 15 00:13 avahi-daemon
-rwxr-xr-x 1 root root 492 Dec 14 23:23 banner.sh
-rwxr-xr-x 1 root root 1922 Dec 14 23:23 bootmisc.sh
-rwxr-xr-x 1 root root 1042 Dec 14 23:50 busybox-udhcpd
-rwxr-xr-x 1 root root 3581 Dec 14 23:23 checkroot.sh
-rwxr-xr-x 1 root root 2887 Dec 15 00:11 dbus-1
-rwxr-xr-x 1 root root 526 Dec 14 23:23 devpts.sh
-rwxr-xr-x 1 root root 353 Dec 14 23:23 dmesg.sh
-rwxr-xr-x 1 root root 3002 Dec 15 00:00 dropbear
lrwxrwxrwx 1 root root 33 Dec 15 2016 functions -> /etc/init.d/functions.initscripts
-rw-r--r-- 1 root root 2141 Dec 14 23:23 functions.initscripts
-rwxr-xr-x 1 root root 2389 Dec 14 23:48 gplv3-notice
-rwxr-xr-x 1 root root 510 Dec 14 23:23 halt
-rwxr-xr-x 1 root root 546 Dec 15 00:00 hostapd
-rwxr-xr-x 1 root root 580 Dec 14 23:23 hostname.sh
-rwxr-xr-x 1 root root 2541 Dec 14 23:50 hwclock.sh
-rwxr-xr-x 1 root root 579 Dec 14 23:50 inetd.busybox
-rwxr-xr-x 1 root root 632 Dec 14 23:52 lighttpd
-rwxr-xr-x 1 root root 1102 Dec 14 23:51 matrix-gui-2.0
-rwxr-xr-x 1 root root 1223 Dec 14 23:48 modutils.sh
-rwxr-xr-x 1 root root 859 Dec 14 23:23 mountall.sh
-rwxr-xr-x 1 root root 1522 Dec 14 23:23 mountnfs.sh
-rwxr-xr-x 1 root root 2124 Dec 14 23:48 networking
-rwxr-xr-x 1 root root 1609 Dec 14 23:49 nfscommon
-rwxr-xr-x 1 root root 516 Dec 15 00:15 ofono
-rwxr-xr-x 1 root root 1950 Dec 15 00:00 parse-ip
-rwxr-xr-x 1 root root 6721 Dec 14 23:23 populate-volatile.sh
-rwxr-xr-x 1 root root 521 Dec 14 23:50 psplash.sh
-rwxr-xr-x 1 1001 1001 3203 Dec 14 23:15 rc.pvr
-rwxr-xr-x 1 root root 968 Dec 14 23:23 read-only-rootfs-hook.sh
-rwxr-xr-x 1 root root 289 Dec 14 23:23 reboot
-rwxr-xr-x 1 root root 585 Dec 14 23:23 rmnologin.sh
-rwxr-xr-x 1 root root 1098 Dec 14 23:48 rng-tools
-rwxr-xr-x 1 root root 1827 Dec 15 00:12 rpcbind
-rwxr-xr-x 1 root root 25 Dec 14 23:47 run-postinsts
-rwxr-xr-x 1 root root 336 Dec 14 23:23 save-rtc.sh
-rwxr-xr-x 1 root root 438 Dec 14 23:23 sendsigs
-rwxr-xr-x 1 root root 578 Dec 14 23:23 single
-rwxr-xr-x 1 root root 782 Dec 14 23:23 sysfs.sh
lrwxrwxrwx 1 root root 26 Dec 15 2016 syslog -> /etc/init.d/syslog.busybox
-rwxr-xr-x 1 root root 1715 Dec 14 23:50 syslog.busybox
-rwxr-xr-x 1 root root 3183 Dec 15 00:09 systemd-udevd
-rwxr-xr-x 1 root root 1455 Dec 14 23:48 telnetd
-rwxr-xr-x 1 root root 414 Dec 14 23:48 thermal-zone-init
-rwxr-xr-x 1 root root 1033 Dec 14 23:48 thttpd
-rwxr-xr-x 1 root root 663 Dec 15 00:00 uim-sysfs
-rwxr-xr-x 1 root root 516 Dec 14 23:23 umountfs
-rwxr-xr-x 1 root root 711 Dec 14 23:23 umountnfs.sh
-rwxr-xr-x 1 root root 1473 Dec 14 23:23 urandom
-rwxr-xr-x 1 root root 2750 Dec 15 00:00 weston
2.1 systemctl 확인 사항
상위 init script에 대해 알아봤으니, 이제 systemd의 기본 명령어인 systemctl 을 이용하여 기본설정과 현재 동작하는 순서에 대해서 알아보자.
root@am335x-evm:/# systemctl get-default // default mode 확인
root@am335x-evm:/# systemctl list-dependencies multi-user.target // default-mode 관련부분 list 확인
.......
root@am335x-evm:/# systemctl list-unit-files // unit 관련 list 전부확인
........
2.2 systemd unit 기능 확인 (AM335x-SK)
# systemctl get-default // 현재 boot mode 3
multi-user.target
상위 runlevel과 동일하며, 3에 해당하는 유저로, 만약 X Server를 이용한다면, graphical. target으로 나올 것이다.
default.target -> /lib/systemd/system/multi-user.target
이런식으로 현재 분석을 하고 있으며, 추후 더 시간이 있을 경우 다시 분석
$ grep WantedBy=multi-user.target -r /lib/systemd/system // 확인
$ grep WantedBy=multi-user.target -r /etc/systemd/system // 확인
$ grep WantedBy=sysinit.target -r /lib/systemd/system
$ ls multi-user.target.wants // 확인
Unit 문법확인
https://www.freedesktop.org/software/systemd/man/systemd.unit.html
일반적인 사용되는 Unit 전체구조 설명
https://www.freedesktop.org/software/systemd/man/systemd.special.html#
*. slice 의 부분설명 (machine.slice, system.slice, user.slice )
https://www.freedesktop.org/software/systemd/man/systemd.special.html#Special%20Slice%20Units
sysinit.target : 기본적으로 실행되는 곳
https://www.freedesktop.org/software/systemd/man/systemd.special.html#sysinit.target
- 각 unit 확인 (/etc/systemd/system)
/etc/systemd/system 의 unit은 대부분 link로 구성이 되며 사용되는것은 /lib/systemd/system 에 연결 or 사용되지 않는다면 /dev/null 연결
별도로 추가한다면 이곳에 추가
root@am335x-evm:/# cd /etc/systemd/system // 사용하는 service는 /lib or /etc/systemd/system
root@am335x-evm:/etc/systemd/system# ls -al
drwxr-xr-x 11 root root 4096 Dec 15 02:24 .
drwxr-xr-x 5 root root 4096 Dec 14 23:43 ..
lrwxrwxrwx 1 root root 9 Dec 15 02:23 banner.service -> /dev/null // 사용하지 않는다면, /dev/null link 하며, 사용한다면, /lib/systemd/system link
drwxr-xr-x 2 root root 4096 Dec 14 23:15 basic.target.wants
drwxr-xr-x 2 root root 4096 Dec 15 02:23 bluetooth.target.wants
lrwxrwxrwx 1 root root 9 Dec 15 02:23 bootmisc.service -> /dev/null
lrwxrwxrwx 1 root root 9 Dec 15 02:23 busybox-udhcpc.service -> /dev/null
lrwxrwxrwx 1 root root 9 Dec 15 02:23 checkfs.service -> /dev/null
lrwxrwxrwx 1 root root 9 Dec 15 02:23 checkroot.service -> /dev/null
lrwxrwxrwx 1 root root 9 Dec 15 02:23 dbus-1.service -> /dev/null
lrwxrwxrwx 1 root root 37 Dec 15 02:23 dbus-org.bluez.service -> /lib/systemd/system/bluetooth.service
lrwxrwxrwx 1 root root 40 Dec 15 02:23 dbus-org.freedesktop.Avahi.service -> /lib/systemd/system/avahi-daemon.service
lrwxrwxrwx 1 root root 37 Dec 15 02:24 default.target -> /lib/systemd/system/multi-user.target
lrwxrwxrwx 1 root root 9 Dec 15 02:23 devpts.service -> /dev/null
lrwxrwxrwx 1 root root 9 Dec 15 02:23 dmesg.service -> /dev/null
drwxr-xr-x 2 root root 4096 Dec 15 02:22 getty.target.wants
lrwxrwxrwx 1 root root 9 Dec 15 02:23 hostname.service -> /dev/null
lrwxrwxrwx 1 root root 9 Dec 15 02:23 hwclock.service -> /dev/null
drwxr-xr-x 2 root root 4096 Dec 15 02:23 local-fs.target.wants
lrwxrwxrwx 1 root root 9 Dec 15 02:23 modutils.service -> /dev/null
lrwxrwxrwx 1 root root 9 Dec 15 02:23 mountall.service -> /dev/null
lrwxrwxrwx 1 root root 9 Dec 15 02:23 mountnfs.service -> /dev/null
drwxr-xr-x 2 root root 4096 Dec 15 02:23 multi-user.target.wants
drwxr-xr-x 2 root root 4096 Dec 15 00:09 network-online.target.wants
lrwxrwxrwx 1 root root 9 Dec 15 02:23 networking.service -> /dev/null
lrwxrwxrwx 1 root root 9 Dec 15 02:23 nfscommon.service -> /dev/null
lrwxrwxrwx 1 root root 9 Dec 15 02:23 nfsserver.service -> /dev/null
lrwxrwxrwx 1 root root 9 Dec 15 02:23 populate-volatile.service -> /dev/null
lrwxrwxrwx 1 root root 9 Dec 15 02:23 psplash.service -> /dev/null
lrwxrwxrwx 1 root root 9 Dec 15 02:23 read-only-rootfs-hook.service -> /dev/null
lrwxrwxrwx 1 root root 9 Dec 15 02:23 rmnologin.service -> /dev/null
drwxr-xr-x 2 root root 4096 Dec 15 02:23 sockets.target.wants
-rw-r--r-- 1 root root 327 Dec 15 00:09 sync-clocks.service
lrwxrwxrwx 1 root root 9 Dec 15 02:23 sysfs.service -> /dev/null
drwxr-xr-x 2 root root 4096 Dec 14 23:15 sysinit.target.wants
lrwxrwxrwx 1 root root 9 Dec 15 02:23 syslog.busybox.service -> /dev/null
lrwxrwxrwx 1 root root 42 Dec 15 02:23 syslog.service -> /lib/systemd/system/busybox-syslog.service
-rw-r--r-- 1 root root 709 Dec 15 00:09 systemd-hostnamed.service
drwxr-xr-x 2 root root 4096 Dec 15 02:23 systemd-random-seed.service.wants
-rw-r--r-- 1 root root 843 Dec 15 00:09 systemd-udevd.service
lrwxrwxrwx 1 root root 9 Dec 15 02:23 urandom.service -> /dev/null
- 각 unit 확인 (/lib/systemd/system)
기본으로 제공되는 unit으로 많이사용하는 것을 이곳에 넣어 보관
root@am335x-evm:/# cd /lib/systemd/system
root@am335x-evm:/lib/systemd/system# ls -al
-rw-r--r-- 1 root root 403 Dec 15 00:09 -.slice
drwxr-xr-x 19 root root 12288 Dec 15 02:23 .
drwxr-xr-x 8 root root 4096 Dec 14 23:50 ..
-rw-r--r-- 1 root root 506 Dec 15 00:10 alsa-restore.service
-rw-r--r-- 1 root root 410 Dec 15 00:10 alsa-state.service
lrwxrwxrwx 1 root root 14 Dec 15 00:09 autovt@.service -> getty@.service
-rw-r--r-- 1 root root 1044 Dec 15 00:13 avahi-daemon.service
-rw-r--r-- 1 root root 874 Dec 15 00:13 avahi-daemon.socket
-rw-r--r-- 1 root root 879 Dec 15 00:09 basic.target
drwxr-xr-x 2 root root 4096 Dec 15 00:10 basic.target.wants
-rw-r--r-- 1 root root 176 Dec 15 00:13 bluetooth.service
-rw-r--r-- 1 root root 379 Dec 15 00:09 bluetooth.target
-rw-r--r-- 1 root root 358 Dec 15 00:09 busnames.target
drwxr-xr-x 2 root root 4096 Dec 15 00:09 busnames.target.wants
-rw-r--r-- 1 root root 116 Dec 14 23:50 busybox-klogd.service
-rw-r--r-- 1 root root 270 Dec 14 23:50 busybox-syslog.service
-rw-r--r-- 1 root root 770 Dec 15 00:09 console-getty.service
-rw-r--r-- 1 root root 752 Dec 15 00:09 console-shell.service
-rw-r--r-- 1 root root 791 Dec 15 00:09 container-getty@.service
lrwxrwxrwx 1 root root 13 Dec 15 00:09 ctrl-alt-del.target -> reboot.target
lrwxrwxrwx 1 root root 25 Dec 15 00:09 dbus-org.freedesktop.hostname1.service -> systemd-hostnamed.service
lrwxrwxrwx 1 root root 23 Dec 15 00:09 dbus-org.freedesktop.locale1.service -> systemd-localed.service
lrwxrwxrwx 1 root root 22 Dec 15 00:09 dbus-org.freedesktop.login1.service -> systemd-logind.service
lrwxrwxrwx 1 root root 24 Dec 15 00:09 dbus-org.freedesktop.machine1.service -> systemd-machined.service
lrwxrwxrwx 1 root root 24 Dec 15 00:09 dbus-org.freedesktop.network1.service -> systemd-networkd.service
lrwxrwxrwx 1 root root 24 Dec 15 00:09 dbus-org.freedesktop.resolve1.service -> systemd-resolved.service
lrwxrwxrwx 1 root root 25 Dec 15 00:09 dbus-org.freedesktop.timedate1.service -> systemd-timedated.service
-rw-r--r-- 1 root root 366 Dec 15 00:11 dbus.service
-rw-r--r-- 1 root root 106 Dec 15 00:11 dbus.socket
drwxr-xr-x 2 root root 4096 Dec 15 00:11 dbus.target.wants
-rw-r--r-- 1 root root 1008 Dec 15 00:09 debug-shell.service
lrwxrwxrwx 1 root root 16 Dec 15 00:09 default.target -> graphical.target
-rw-r--r-- 1 root root 670 Dec 15 00:09 dev-hugepages.mount
-rw-r--r-- 1 root root 624 Dec 15 00:09 dev-mqueue.mount
-rw-r--r-- 1 root root 131 Dec 15 00:00 dropbear.socket
-rw-r--r-- 1 root root 384 Dec 15 00:00 dropbear@.service
-rw-r--r-- 1 root root 453 Dec 15 00:00 dropbearkey.service
-rw-r--r-- 1 root root 995 Dec 15 00:09 emergency.service
-rw-r--r-- 1 root root 431 Dec 15 00:09 emergency.target
-rw-r--r-- 1 root root 501 Dec 15 00:09 exit.target
-rw-r--r-- 1 root root 440 Dec 15 00:09 final.target
-rw-r--r-- 1 root root 420 Dec 15 00:00 gadget-init.service
-rw-r--r-- 1 root root 460 Dec 15 00:09 getty.target
-rw-r--r-- 1 root root 1536 Dec 15 00:09 getty@.service
-rw-r--r-- 1 root root 198 Dec 14 23:48 gplv3-notice.service
-rw-r--r-- 1 root root 558 Dec 15 00:09 graphical.target
drwxr-xr-x 2 root root 4096 Dec 15 00:09 graphical.target.wants
-rw-r--r-- 1 root root 565 Dec 15 00:09 halt-local.service
-rw-r--r-- 1 root root 487 Dec 15 00:09 halt.target
-rw-r--r-- 1 root root 447 Dec 15 00:09 hibernate.target
-rw-r--r-- 1 root root 468 Dec 15 00:09 hybrid-sleep.target
-rw-r--r-- 1 root root 630 Dec 15 00:09 initrd-cleanup.service
-rw-r--r-- 1 root root 553 Dec 15 00:09 initrd-fs.target
-rw-r--r-- 1 root root 790 Dec 15 00:09 initrd-parse-etc.service
-rw-r--r-- 1 root root 526 Dec 15 00:09 initrd-root-fs.target
-rw-r--r-- 1 root root 640 Dec 15 00:09 initrd-switch-root.service
-rw-r--r-- 1 root root 691 Dec 15 00:09 initrd-switch-root.target
-rw-r--r-- 1 root root 664 Dec 15 00:09 initrd-udevadm-cleanup-db.service
-rw-r--r-- 1 root root 671 Dec 15 00:09 initrd.target
-rw-r--r-- 1 root root 501 Dec 15 00:09 kexec.target
-rw-r--r-- 1 root root 677 Dec 15 00:09 kmod-static-nodes.service
-rw-r--r-- 1 root root 658 Dec 15 00:09 ldconfig.service
-rw-r--r-- 1 root root 292 Dec 14 23:52 lighttpd.service
-rw-r--r-- 1 root root 395 Dec 15 00:09 local-fs-pre.target
-rw-r--r-- 1 root root 507 Dec 15 00:09 local-fs.target
drwxr-xr-x 2 root root 4096 Dec 15 00:09 local-fs.target.wants
-rw-r--r-- 1 root root 405 Dec 15 00:09 machine.slice
-rw-r--r-- 1 root root 531 Dec 15 00:09 machines.target
-rw-r--r-- 1 root root 492 Dec 15 00:09 multi-user.target
drwxr-xr-x 2 root root 4096 Dec 15 02:22 multi-user.target.wants
-rw-r--r-- 1 root root 464 Dec 15 00:09 network-online.target
-rw-r--r-- 1 root root 461 Dec 15 00:09 network-pre.target
-rw-r--r-- 1 root root 480 Dec 15 00:09 network.target
-rw-r--r-- 1 root root 250 Dec 14 23:49 nfs-statd.service
-rw-r--r-- 1 root root 514 Dec 15 00:09 nss-lookup.target
-rw-r--r-- 1 root root 473 Dec 15 00:09 nss-user-lookup.target
-rw-r--r-- 1 root root 183 Dec 15 00:15 ofono.service
-rw-r--r-- 1 root root 521 Dec 14 23:50 opkg-configure.service
-rw-r--r-- 1 root root 554 Dec 15 00:09 org.freedesktop.hostname1.busname
-rw-r--r-- 1 root root 550 Dec 15 00:09 org.freedesktop.locale1.busname
-rw-r--r-- 1 root root 598 Dec 15 00:09 org.freedesktop.login1.busname
-rw-r--r-- 1 root root 549 Dec 15 00:09 org.freedesktop.machine1.busname
-rw-r--r-- 1 root root 675 Dec 15 00:09 org.freedesktop.network1.busname
-rw-r--r-- 1 root root 763 Dec 15 00:09 org.freedesktop.resolve1.busname
-rw-r--r-- 1 root root 480 Dec 15 00:09 org.freedesktop.systemd1.busname
-rw-r--r-- 1 root root 538 Dec 15 00:09 org.freedesktop.timedate1.busname
-rw-r--r-- 1 root root 354 Dec 15 00:09 paths.target
-rw-r--r-- 1 root root 552 Dec 15 00:09 poweroff.target
drwxr-xr-x 2 root root 4096 Dec 15 00:09 poweroff.target.wants
-rw-r--r-- 1 root root 377 Dec 15 00:09 printer.target
-rw-r--r-- 1 root root 178 Dec 15 00:16 ptpd.service
-rw-r--r-- 1 root root 576 Dec 15 00:09 quotaon.service
-rw-r--r-- 1 root root 612 Dec 15 00:09 rc-local.service
-rw-r--r-- 1 root root 543 Dec 15 00:09 reboot.target
drwxr-xr-x 2 root root 4096 Dec 15 00:09 reboot.target.wants
-rw-r--r-- 1 root root 396 Dec 15 00:09 remote-fs-pre.target
-rw-r--r-- 1 root root 482 Dec 15 00:09 remote-fs.target
-rw-r--r-- 1 root root 988 Dec 15 00:09 rescue.service
-rw-r--r-- 1 root root 486 Dec 15 00:09 rescue.target
drwxr-xr-x 2 root root 4096 Dec 15 00:09 rescue.target.wants
-rw-r--r-- 1 root root 212 Dec 15 00:12 rpcbind.service
-rw-r--r-- 1 root root 132 Dec 15 00:12 rpcbind.socket
-rw-r--r-- 1 root root 500 Dec 15 00:09 rpcbind.target
-rw-r--r-- 1 root root 385 Dec 14 23:47 run-postinsts.service
lrwxrwxrwx 1 root root 15 Dec 15 00:09 runlevel0.target -> poweroff.target
lrwxrwxrwx 1 root root 13 Dec 15 00:09 runlevel1.target -> rescue.target
drwxr-xr-x 2 root root 4096 Dec 15 00:09 runlevel1.target.wants
lrwxrwxrwx 1 root root 17 Dec 15 00:09 runlevel2.target -> multi-user.target
drwxr-xr-x 2 root root 4096 Dec 15 00:09 runlevel2.target.wants
lrwxrwxrwx 1 root root 17 Dec 15 00:09 runlevel3.target -> multi-user.target
drwxr-xr-x 2 root root 4096 Dec 15 00:09 runlevel3.target.wants
lrwxrwxrwx 1 root root 17 Dec 15 00:09 runlevel4.target -> multi-user.target
drwxr-xr-x 2 root root 4096 Dec 15 00:09 runlevel4.target.wants
lrwxrwxrwx 1 root root 16 Dec 15 00:09 runlevel5.target -> graphical.target
drwxr-xr-x 2 root root 4096 Dec 15 00:09 runlevel5.target.wants
lrwxrwxrwx 1 root root 13 Dec 15 00:09 runlevel6.target -> reboot.target
-rw-r--r-- 1 root root 1059 Dec 14 23:23 serial-getty@.service
-rw-r--r-- 1 root root 402 Dec 15 00:09 shutdown.target
-rw-r--r-- 1 root root 362 Dec 15 00:09 sigpwr.target
-rw-r--r-- 1 root root 420 Dec 15 00:09 sleep.target
-rw-r--r-- 1 root root 409 Dec 15 00:09 slices.target
-rw-r--r-- 1 root root 380 Dec 15 00:09 smartcard.target
-rw-r--r-- 1 root root 356 Dec 15 00:09 sockets.target
drwxr-xr-x 2 root root 4096 Dec 15 02:22 sockets.target.wants
-rw-r--r-- 1 root root 380 Dec 15 00:09 sound.target
-rw-r--r-- 1 root root 204 Dec 15 00:03 strongswan.service
-rw-r--r-- 1 root root 441 Dec 15 00:09 suspend.target
-rw-r--r-- 1 root root 353 Dec 15 00:09 swap.target
-rw-r--r-- 1 root root 715 Dec 15 00:09 sys-fs-fuse-connections.mount
-rw-r--r-- 1 root root 719 Dec 15 00:09 sys-kernel-config.mount
-rw-r--r-- 1 root root 662 Dec 15 00:09 sys-kernel-debug.mount
-rw-r--r-- 1 root root 518 Dec 15 00:09 sysinit.target
drwxr-xr-x 2 root root 4096 Dec 15 02:22 sysinit.target.wants
lrwxrwxrwx 1 root root 9 Dec 14 23:50 syslog.service -> /dev/null
-rw-r--r-- 1 root root 1235 Dec 15 00:09 syslog.socket
-rw-r--r-- 1 root root 585 Dec 15 00:09 system-update.target
-rw-r--r-- 1 root root 436 Dec 15 00:09 system.slice
-rw-r--r-- 1 root root 646 Dec 15 00:09 systemd-ask-password-console.path
-rw-r--r-- 1 root root 653 Dec 15 00:09 systemd-ask-password-console.service
-rw-r--r-- 1 root root 574 Dec 15 00:09 systemd-ask-password-wall.path
-rw-r--r-- 1 root root 681 Dec 15 00:09 systemd-ask-password-wall.service
-rw-r--r-- 1 root root 724 Dec 15 00:09 systemd-backlight@.service
-rw-r--r-- 1 root root 650 Dec 15 00:09 systemd-bootchart.service
-rw-r--r-- 1 root root 497 Dec 15 00:09 systemd-exit.service
-rw-r--r-- 1 root root 755 Dec 15 00:09 systemd-firstboot.service
-rw-r--r-- 1 root root 574 Dec 15 00:09 systemd-fsck-root.service
-rw-r--r-- 1 root root 600 Dec 15 00:09 systemd-fsck@.service
-rw-r--r-- 1 root root 544 Dec 15 00:09 systemd-halt.service
-rw-r--r-- 1 root root 631 Dec 15 00:09 systemd-hibernate-resume@.service
-rw-r--r-- 1 root root 501 Dec 15 00:09 systemd-hibernate.service
-rw-r--r-- 1 root root 710 Dec 15 00:09 systemd-hostnamed.service
-rw-r--r-- 1 root root 778 Dec 15 00:09 systemd-hwdb-update.service
-rw-r--r-- 1 root root 519 Dec 15 00:09 systemd-hybrid-sleep.service
-rw-r--r-- 1 root root 480 Dec 15 00:09 systemd-initctl.service
-rw-r--r-- 1 root root 524 Dec 15 00:09 systemd-initctl.socket
-rw-r--r-- 1 root root 667 Dec 15 00:09 systemd-journal-catalog-update.service
-rw-r--r-- 1 root root 731 Dec 15 00:09 systemd-journal-flush.service
-rw-r--r-- 1 root root 607 Dec 15 00:09 systemd-journald-audit.socket
-rw-r--r-- 1 root root 1090 Dec 15 00:09 systemd-journald-dev-log.socket
-rw-r--r-- 1 root root 1293 Dec 15 00:09 systemd-journald.service
-rw-r--r-- 1 root root 842 Dec 15 00:09 systemd-journald.socket
-rw-r--r-- 1 root root 557 Dec 15 00:09 systemd-kexec.service
-rw-r--r-- 1 root root 691 Dec 15 00:09 systemd-localed.service
-rw-r--r-- 1 root root 1126 Dec 15 00:09 systemd-logind.service
-rw-r--r-- 1 root root 693 Dec 15 00:09 systemd-machine-id-commit.service
-rw-r--r-- 1 root root 948 Dec 15 00:09 systemd-machined.service
-rw-r--r-- 1 root root 967 Dec 15 00:09 systemd-modules-load.service
-rw-r--r-- 1 root root 685 Dec 15 00:09 systemd-networkd-wait-online.service
-rw-r--r-- 1 root root 1339 Dec 15 00:09 systemd-networkd.service
-rw-r--r-- 1 root root 591 Dec 15 00:09 systemd-networkd.socket
-rw-r--r-- 1 root root 1378 Dec 15 00:09 systemd-nspawn@.service
-rw-r--r-- 1 root root 553 Dec 15 00:09 systemd-poweroff.service
-rw-r--r-- 1 root root 618 Dec 15 00:09 systemd-quotacheck.service
-rw-r--r-- 1 root root 717 Dec 15 00:09 systemd-random-seed.service
-rw-r--r-- 1 root root 548 Dec 15 00:09 systemd-reboot.service
-rw-r--r-- 1 root root 757 Dec 15 00:09 systemd-remount-fs.service
-rw-r--r-- 1 root root 907 Dec 15 00:09 systemd-resolved.service
-rw-r--r-- 1 root root 696 Dec 15 00:09 systemd-rfkill.service
-rw-r--r-- 1 root root 617 Dec 15 00:09 systemd-rfkill.socket
-rw-r--r-- 1 root root 497 Dec 15 00:09 systemd-suspend.service
-rw-r--r-- 1 root root 649 Dec 15 00:09 systemd-sysctl.service
-rw-r--r-- 1 root root 655 Dec 15 00:09 systemd-timedated.service
-rw-r--r-- 1 root root 1032 Dec 15 00:09 systemd-timesyncd.service
-rw-r--r-- 1 root root 598 Dec 15 00:09 systemd-tmpfiles-clean.service
-rw-r--r-- 1 root root 450 Dec 15 00:09 systemd-tmpfiles-clean.timer
-rw-r--r-- 1 root root 703 Dec 15 00:09 systemd-tmpfiles-setup-dev.service
-rw-r--r-- 1 root root 683 Dec 15 00:09 systemd-tmpfiles-setup.service
-rw-r--r-- 1 root root 823 Dec 15 00:09 systemd-udev-settle.service
-rw-r--r-- 1 root root 743 Dec 15 00:09 systemd-udev-trigger.service
-rw-r--r-- 1 root root 578 Dec 15 00:09 systemd-udevd-control.socket
-rw-r--r-- 1 root root 570 Dec 15 00:09 systemd-udevd-kernel.socket
-rw-r--r-- 1 root root 842 Dec 15 00:09 systemd-udevd.service
-rw-r--r-- 1 root root 630 Dec 15 00:09 systemd-update-done.service
-rw-r--r-- 1 root root 757 Dec 15 00:09 systemd-update-utmp-runlevel.service
-rw-r--r-- 1 root root 754 Dec 15 00:09 systemd-update-utmp.service
-rw-r--r-- 1 root root 573 Dec 15 00:09 systemd-user-sessions.service
-rw-r--r-- 1 root root 613 Dec 15 00:09 systemd-vconsole-setup.service
-rw-r--r-- 1 root root 395 Dec 15 00:09 time-sync.target
-rw-r--r-- 1 root root 405 Dec 15 00:09 timers.target
drwxr-xr-x 2 root root 4096 Dec 15 00:09 timers.target.wants
-rw-r--r-- 1 root root 625 Dec 15 00:09 tmp.mount
-rw-r--r-- 1 root root 417 Dec 15 00:09 umount.target
-rw-r--r-- 1 root root 392 Dec 15 00:09 user.slice
-rw-r--r-- 1 root root 528 Dec 15 00:09 user@.service
-rw-r--r-- 1 root root 475 Dec 15 00:09 var-lib-machines.mount
-rw-r--r-- 1 root root 496 Dec 14 23:22 var-volatile-lib.service
root@am335x-evm:/lib/systemd/system# cd /usr/lib/systemd // system 이 존재하지 않음
root@am335x-evm:/usr/lib/systemd# ls -al
drwxr-xr-x 6 root root 4096 Dec 15 2016 .
drwxr-xr-x 56 root root 53248 Dec 15 2016 ..
drwxr-xr-x 2 root root 4096 Dec 15 2016 catalog
drwxr-xr-x 2 root root 4096 Dec 15 2016 network
drwxr-xr-x 2 root root 4096 Dec 15 2016 user
drwxr-xr-x 2 root root 4096 Dec 15 2016 user-generators
- 전체 service status 확인 및 기본분석
방향키가 상 아래가 동작이 되며, 실시간으로 반영이 되기 때문에 확인가능
서비스 종료를 원한다면 q를 사용
- /etc/systemd/system.conf : /lib/systemd/systemd --system 설정 : Consol에서만 가능
- /etc/systemd/user.conf : /lib/systemd/systemd --user 설정 : SSH로 로그인시 확인가능
#systemctl status // 현재 전체 service 확인
?? am335x-evm
State: running
Jobs: 0 queued
Failed: 0 units
Since: Thu 1970-01-01 00:00:02 UTC; 46 years 11 months ago
CGroup: /
???€init.scope // init.scope 영역 , 만약 ssh를 사용하여 login을 한다면, user.slice가 존재
?? ???€1 /sbin/init // PID 1 /sbin/init
???€system.slice //systemd 로 실행되는 각 service들
?? ???€avahi-daemon.service
?? ?? ???€502 avahi-daemon: running [am335x-evm.local // 502는 PID, init scirpt도 존재
?? ?? ???€524 avahi-daemon: chroot helpe
?? ???€dbus.service
?? ?? ???€475 /usr/bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-activation
?? ???€lighttpd.service
?? ?? ???€695 /usr/sbin/lighttpd -D -f /etc/lighttpd.conf
?? ???€matrix-gui-2.0.service
?? ?? ???€857 /usr/bin/matrix_browser http://localhost:80/
?? ???€weston.service
?? ?? ???€811 /bin/sh /usr/bin/runWeston
?? ?? ???€814 weston --idle-time=0
?? ?? ???€826 /usr/libexec/weston-keyboard
?? ?? ???€828 /usr/libexec/weston-desktop-shell
?? ???€busybox-klogd.service
?? ?? ???€506 /sbin/klogd -n
?? ???€telnetd.service
?? ?? ???€819 /usr/sbin/telnetd
?? ???€system-serial\x2dgetty.slice
?? ?? ???€serial-getty@ttyS3.service
?? ?? ?? ???€1018 /sbin/agetty -8 -L ttyS3 115200 xterm
?? ?? ???€serial-getty@ttyGS0.service
?? ?? ???€685 /sbin/agetty -8 -L ttyGS0 115200 xterm
?? ???€systemd-journald.service
?? ?? ???€99 /lib/systemd/systemd-journald
?? ???€busybox-udhcpd.service
?? ?? ???€833 /usr/sbin/udhcpd -S /etc/udhcpd_usb0.conf
?? ???€thttpd.service
?? ?? ???€831 /usr/sbin/thttpd -d /srv/www -p 8080
?? ???€systemd-resolved.service
?? ?? ???€687 /lib/systemd/systemd-resolved
?? ???€systemd-timesyncd.service
?? ?? ???€396 /lib/systemd/systemd-timesyncd
?? ???€systemd-logind.service
?? ?? ???€465 /lib/systemd/systemd-logind
?? ???€systemd-networkd.service
?? ?? ???€496 /lib/systemd/systemd-networkd
?? ???€system-getty.slice
?? ?? ???€getty@tty1.service
?? ?? ???€682 /sbin/agetty --noclear tty1 linux
?? ???€ofono.service
.......
https://wiki.archlinux.org/index.php/systemd
https://websetnet.com/ko/manage-systemd-services-and-units/
http://www.phytec.eu/fileadmin/user_upload/downloads/Manuals/L-818e_1.pdf
https://e2e.ti.com/support/embedded/linux/f/354/t/324198
