Wiki source code of Openwrt Notes

Version 11.1 by Leon Poon on 2019/01/06 09:40
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1
2
3 = initramfs-kernel =
4
5 kernel runs /init.
6
7 /init is a script which sets INITRAMFS=1 and then execs /sbin/init.
8
9 /sbin/init is ELF comes from procd package. What it does (as pid=1):
10
11 * early (different from procd early):
12 ** mount /proc, /sysfs, and create /dev nodes, create /tmp subdirs etc
13 ** set PATH
14 * kmodloader in subprocess (waits until done)
15 * preinit
16 ** plugd in subprocess (seem to deal with firmware)
17 ** /etc/preinit in subprocess
18 * when /etc/preinit is done then it execvp the "real" /sbin/procd
19
20 procd states:
21
22 * early (first state):
23 ** coldplug (remount /dev, etc)
24 *** start udevtrigger in subproc
25 *** when udevtrigger completes, hotplug
26 *** when hotplug completes, next state (ubus)
27 * ubus:
28 ** start attempts to connect to ubs
29 ** start ubus as service
30 ** once connection's done then next state (init)
31 * init - read /etc/inittab and run:
32 ** respawn - things that need to keep rerunning once quitted
33 ** askconsole
34 ** askfirst - the "Press Enter to activate this console" message
35 ** sysinit - (usually /etc/init.d/rcS with S) and then next state (running)
36 * running - waits for shutdown signal (usr1/usr2) or reboot (int/term)
37 * shutdown
38 ** runs shutdown command per inittab (also /etc/init.d/rcS but with K)
39 ** when done next state (halt)
40 * halt - kill everything and either enter sleep loop or reboots
41
42 = Debian =
43
44 Things to do after debootstrap:
45
46 * [[get rid of systemd>>http://without-systemd.org/wiki/index.php/How_to_remove_systemd_from_a_Debian_Stretch_installation]]
47 * set root password
48 * install openssh-server
49 * /etc/network/interfaces (TODO: swconfig while still in openwrt initramfs space?)
50 * read-only root
51
52 Needs CONFIG_DEVTMPFS=y in kernel.
53
54 {{code language="bash"}}
55 mkdir -pv /mnt/debian && mknod /dev/sda b 8 0 && cryptsetup open /dev/sda usb && vgchange -ay vol_grp1 && mount /dev/vol_grp1/logical_vol1 /mnt/debian
56 {{/code}}
57
58 {{code language="bash"}}
59 chroot /mnt/debian /bin/bash
60 {{/code}}
61
62 {{code language="bash"}}
63 mount proc /proc -t proc
64 {{/code}}
65
66 {{code language="bash"}}
67 exec switch_root /mnt/debian /sbin/init
68 {{/code}}
69
70 {{code language="bash"}}
71 ip addr add dev eth0 IP/NM
72 ip link set eth0 up
73 ip route add default via GW
74 {{/code}}