- Introduction
- Features
- /etc/finit.conf
- /etc/finit.d
- Runparts
- Bootstrap
- Runlevels
- Inetd
- Hooks, Callbacks & Plugins
- Rebooting & Halting
- Commands & Status
- Building
- Running
- Debugging
- Origin & References
Init is the first userland process started by the UNIX kernel, therefore it always has PID 1 and is responsible for starting up the rest of the system.
Finit is a plugin-based init with process supervision similar to that of D.J. Bernstein's daemontools and Gerrit Pape's runit. The main focus of Finit is on small and embedded GNU/Linux systems, yet fully functional on standard server and desktop installations as well.
Traditional SysV init style systems are scripted. For low-resource embedded systems this can be quite resource intensive and cause longer boot times. Finit is optimized to reduce context switches and forking of processes to provide a very basic bootstrap written entirely in C.
Finit basically does everything you need from its
main()
function!
Hence, there is no /etc/init.d/rcS
script, or similar, instead Finit
reads its configuration from /etc/finit.conf. This
file details what kernel modules to load, programs to run, daemons to
supervise, and inetd services to launch on demand.
See TroglOS for an example of how to boot a small embedded system with Finit.
Process Supervision
Start, monitor and restart processes (daemons) if they fail.
Inetd
Finit comes with a built-in inetd
server. No need to maintain a
separate config file for services that you want to start on demand.
All inetd services started can be filtered per port and inbound interface, reducing the need for a full blown firewall.
Runlevels
Runlevels are optional in Finit, but support for SysV runlevels is
available if needed. All services in runlevel S(1) are started first,
followed by the desired run-time runlevel. Runlevel S can be started in
sequence by using run [S] cmd
. Changing runlevels at runtime is done
like any other init, e.g. init 4
Plugins
Finit plugins can be callbacks, boot hooks into different stages of
the boot process, or pure extensions. Plugins are written in C and
compiled into a dynamic library that is loaded automatically by finit at
boot. A basic set of plugins that extend and modify the basic behavior
are bundled in the plugins/
directory.
Capabilities:
- Task/Run/Service callbacks
Modify service arguments, override service monitor's decisions to start/stop/reload a service. - Hooks
Hook into the boot at predefined points to extend Finit - I/O
Listen to external events and control Finit behavior/services - Inetd
Extend Finit with internal inetd services, for an example, seeplugins/time.c
Extensions and functionality not purely related to what an /sbin/init
needs to start a system are available as a set of plugins that either
hook into the boot process or respond to various I/O.
Contrary to most other script based init alternatives (SysV init,
upstart, systemd, OpenRC, etc.) Finit reads its entire
configuration from /etc/finit.conf
.
The command line arguments given in /etc/finit.conf
to each service
provide a default. A plugin can be used to register a callback to a
service and then modify the behavior to suit the current runlevel and
system configuration.
For instance, before starting a heavily resource intensive service like IPsec or OpenVPN, a callback can check if the outbound interface is up and has an IP address, or just check if the service is disabled — much like what a SysV init start script usually does.
Syntax:
-
check <DEV>
Run fsck on a file system before mounting it -
module <MODULE>
Load a kernel module, with optional arguments -
network <PATH>
Script or program to bring up networking, with optional arguments -
runlevel <N>
N is the runlevel number 1-9, where 6 is reserved for reboot.
Default is 2. -
run [LVLS] /path/to/cmd ARGS -- Optional description
One-shot command to run in sequence when entering a runlevel, with optional arguments and description. This command is guaranteed to be completed before running the next command. -
task [LVLS] /path/to/cmd ARGS -- Optional description
One-shot like 'run', but starts in parallel with the next command -
service [LVLS] /path/to/daemon ARGS -- Optional description
Service, or daemon, to be monitored and automatically restarted if it exits prematurely. Please note that you often need to provide a--foreground
or--no-background
argument to most daemons to prevent them from forking off a sub-process in the background. -
inetd service/proto[@iflist] <wait|nowait> [LVLS] /path/to/daemon args
Launch a daemon when a client initiates a connection on an Internet port. Available services are listed in the UNIX/etc/services
file. Finit can filter access to from a list of interfaces,@iflist
, per inetd service as well as listen to custom ports.
inetd ftp/tcp nowait @root /usr/sbin/uftpd -i -f
inetd tftp/udp wait @root /usr/sbin/uftpd -i -t
The following example listens to port 2323 for telnet connections and
only allows clients connecting from eth0
:
inetd 2323/tcp@eth0 nowait [2345] /sbin/telnetd -i -F
The interface list, @iflist
, is of the format @iface,!iface,iface
,
where a single !
means to deny access. Notice how interfaces are
comma separated with no spaces.
The inetd
directive can also have -- Optional Description
, only
Finit does not output this text on the console when launching inetd
services. Instead this text is sent to syslog and also shown by the
initctl
tool. More on inetd below.
-
runparts <DIR>
Call run-parts(8) on a directory to run start scripts. All executable files, or scripts, in the directory are called, in alphabetic order. -
include <CONF>
Include another configuration file. Absolute path required. -
tty [LVLS] <DEV | /path/to/cmd [args]>
Start a getty on the given TTY device DEV, in the given runlevels. If no tty setting is given infinit.conf
, or if/bin/sh
is given as argument instead of a device path, a single shell is started on the default console. Useful for really bare-bones systems.It is also possible to supply the full command line, with arguments, to your getty. In this case finit will simply use that command.
See
finit.h
for the#define GETTY
that is called, along with the default baud rate.Note: BusyBox getty, used when Finit is built for embedded systems, can take a
DEV
with or without/dev/
prefix. Make sure to call the configure script with--enable-embedded
if this is what you want. -
console <DEV | /path/to/cmd [args]>
Some embedded systems have a dedicated serial console/service port. This command tells finit to not start getty directly, since there may not be anyone there. To save RAM and CPU finit instead displays a friendly message and waits for the user to activate the console with a key press before starting getty. Finit also does some other magic and changes the process name to "console".Like the
tty
command, theconsole
command can also be used to simply start a UNIX shell, e.g./bin/sh
.
When running make install no default /etc/finit.conf
will
be installed since system requirements differ too much. Try out the
Debian 6.0 example /usr/share/doc/finit/finit.conf
configuration that
is capable of service monitoring SSH, sysklogd, gdm and a console getty!
Every run
, task
, service
, or inetd
can also list the privileges
the /path/to/cmd
should be executed with. Simply prefix the path with
[@USR[:GRP]]
like this:
run [2345] @joe:users /usr/bin/logger "Hello world"
For multiple instances of the same command, e.g. a DHCP client or
multiple web servers, add :ID
somewhere between the run
, task
,
service
keyword and the command, like this:
service :1 [2345] /sbin/httpd -f -h /http -p 80 -- Web server
service :2 [2345] /sbin/httpd -f -h /http -p 8080 -- Old web server
Without the :ID
to the service the latter will overwrite the former
and only the old web server would be started and supervised.
Finit supports changes to the overall system configuration at runtime.
For this purpose the (configurable) directory /etc/finit.d
is used.
Here you can put configuration file snippets, one per service if you
like, which are all sourced automatically by finit at boot when loading
the static configuration from /etc/finit.conf
. This is the default
behavior, so no include directives are necessary.
To add a new service, simply drop a .conf
file in /etc/finit.d
and
send SIGHUP
to PID 1, or call finit q
. Any service read from this
directory is flagged as a dynamic service, so changes to their .conf
files, or even removal of the files, is detected at SIGHUP
.
- If a service's
.conf
file has been removed, the service is stopped. - If the file is modified, the service is reloaded, stopped and started.
- If a new service is detected, it is started — respecting runlevels and return values from any callbacks.
The /etc/finit.d
directory was previously the default Finit runparts
directory. Finit no longer has a default runparts
, so make sure to
update your setup, or the finit configuration, accordingly.
Note: Configurations read from /etc/finit.d
are read after
initial bootstrap, runlevel S(1). Hence, bootstrap services must be
in /etc/finit.conf
!
At the end of the boot, when networking and all services are up, finit
calls its built-in run-parts(8) on the runparts <DIR>
directory,
if it exists. Similar to how the /ec/rc.local
file works in most
other init daemons, only finit runs a directory of scripts. This
replaces the earlier support for a /usr/sbin/services.sh
script in the
original finit.
- Populate
/dev
- Parse
/etc/finit.conf
- Load all
.so
plugins - Remount/Pivot
/
to get R+W - Call 1st level hooks,
HOOK_ROOTFS_UP
- Mount
/etc/fstab
and swap, if available - Cleanup stale files from
/tmp/*
et al - Enable SysV init signals
- Call 2nd level hooks,
HOOK_BASEFS_UP
- Start all 'S' runlevel tasks and services
- Load kernel parameters from
/etc/sysctl.conf
- Set hostname and bring up loopback interface
- Call
network
script, if set in/etc/finit.conf
- Call 3rd level hooks,
HOOK_NETWORK_UP
- Load all
*.conf
files in/etc/finit.d/
and switch to the active active runlevel, as set in/etc/finit.conf
, default is 2. Here is where the rest of all tasks and inetd services are started. - Call 4th level hooks,
HOOK_SVC_UP
- If
runparts <DIR>
is set, run-parts(8) is called on<DIR>
- Call 5th level (last) hooks,
HOOK_SYSTEM_UP
- Start TTYs defined in
/etc/finit.conf
, or rescue on/dev/console
- Enter main monitor loop
In (10) and (15) tasks and services defined in /etc/finit.conf
are
started. Remember, all service
and task
stanzas are started in
parallel and run
in sequence, and in the order listed. Hence, to
emulate a SysV /etc/init.d/rcS
one could write a long file with only
run
statements.
Notice the five hook points that are called at various point in the bootstrap process. This is where plugins can extend the boot in any way they please.
For instance, at HOOK_BASEFS_UP
a plugin could read an XML file from a
USB stick, convert/copy its contents to the system's /etc/
directory,
well before all 'S' runlevel tasks are started. This could be used with
system images that are created read-only and all configuration is stored
on external media.
Basic support for runlevels is included in Finit from v1.8. By
default all services, tasks, run commands and TTYs listed without a set
of runlevels get a default set [234]
assigned. The default runlevel
after boot is 2.
Finit supports runlevels 0-9, and S, with 0 reserved for halt, 6 reboot and S for services to only run at bootstrap. Runlevel 1 is the single user level, where usually no networking is enabled. In Finit this is more of a policy for the user to define. Normally only runlevels 1-6 are used, and even more commonly, only the default runlevel is used.
To specify an allowed set of runlevels for a service
, run
command,
task
, or tty
, add [NNN]
to your /etc/finit.conf
, like this:
service [S12345] /sbin/syslogd -n -x -- System log daemon
run [S] /etc/init.d/acpid start -- Starting ACPI Daemon
task [S] /etc/init.d/kbd start -- Preparing console
service [S12345] /sbin/klogd -n -x -- Kernel log daemon
tty [12345] /dev/tty1
tty [2] /dev/tty2
tty [2] /dev/tty3
tty [2] /dev/tty4
tty [2] /dev/tty5
tty [2] /dev/tty6
In this example syslogd is first started, in parallel, and then acpid is called using a conventional SysV init script. It is called with the run command, meaning the following task command to start the kbd script is not called until the acpid init script has fully completed. Then the keyboard setup script is called in parallel with klogd as a monitored service.
Again, tasks and services are started in parallel, while run commands are called in the order listed and subsequent commands are not started until a run command has completed.
Switching between runlevels can be done by calling init with a single
argument, e.g. init 5 switches to runlevel 5. When changing
runlevels Finit also automatically reloads all .conf
files in the
/etc/finit.d/
directory. So if you want to set a new system config,
switch to runlevel 1, change all config files in the system, and touch
all .conf
files in /etc/finit.d
before switching back to the
previous runlevel again — that way Finit can both stop old services and
start any new ones for you, without rebooting the system.
A built-in Internet Super Server support was added in Finit v1.12 and
v1.13, along with an internal time
inetd service, RFC 868 (rdate).
The latter is supplied as a plugin to illustrate how simple it is to
extend finit with more internal inetd services.
Please note, not all UNIX daemons are prepared to run as inetd services. In the example below
sshd
also need the command line argument-i
.
The inetd support in finit is quite advanced. Not only does it launch
services on demand, it can do so on custom ports and also filter inbound
traffic using a poor man's TCP wrappers. The syntax is very similar
to the traditional /etc/inetd.conf
, yet keeping with the style of
Finit:
# Launch SSH on demand, in runlevels 2-5 as root
inetd ssh/tcp nowait [2345] @root:root /usr/sbin/sshd -i
A more advanced example is listed below, please note the incompatible syntax change that was made between Finit v1.12 and v1.13 to support deny filters:
# Start sshd if inbound connection on eth0, port 222, or
# inbound on eth1, port 22. Ignore on other interfaces.
inetd 222/tcp@eth0 nowait [2345] /usr/sbin/sshd -i
inetd ssh/tcp@eth1,eth1 nowait [2345] /usr/sbin/sshd -i
If eth0
is your Internet interface you may want to avoid using the
default port. To run ssh on port 222, and all others on port 22:
inetd 222/tcp@eth0 nowait [2345] /usr/sbin/sshd -i
inetd ssh/tcp@*,!eth0 nowait [2345] /usr/sbin/sshd -i
Compared to Finit v1.12 you must explicitly deny access from eth0
!
Internal Services
The original inetd
had a few standard services built-in:
- time
- echo
- chargen
- discard
Finit only supports the time
service. This is realized as a plugin to
provide a simple means of testing the inetd functionality stand-alone,
but also as a very rudimentary time server for rdate clients.
The time.so
inetd plugin is set up as follows. Notice the keyword
internal
which applies to all built-in inetd services:
inetd time/tcp nowait [2345] internal
Then call rdate
from a remote machine (or use localhost):
rdate -p <IP>
If you use time/udp
you must use the standard rdate implementation and
then call it with rdate -up
to connect using UDP. Without the -p
argument rdate will try to set the system clock. Please note that rdate
has been deprecated by the NTP protocol and this plugin should only be
used for testing or environments where NTP for some reason is blocked.
Also, remember the UNIX year 2038 bug, or in the case of RFC 868 (and
some NTP implementations), year 2036!
Note: There is currently no verification that the same port is used
more than once. So a standard inetd http/tcp
service will clash
with an ssh entry for the same port inetd 80/tcp
…
Finit provides only the bare necessities for starting and supervising processes, with an emphasis on bare — for your convenience it does however come with support for hooks, service callbacks and plugins that can used to extend finit with.
For your convenience a set of optional plugins are available:
-
alsa-utils.so: Restore and save ALSA sound settings on startup/shutdown.
-
bootmisc.so: Setup necessary files for UTMP, tracks logins at boot.
-
dbus.so: Setup and start system message bus, D-Bus, at boot.
-
hwclock.so: Restore and save system clock from/to RTC on startup/shutdown.
-
initctl.so: Extends finit with a traditional
initctl
functionality. -
netlink.so: Listens to Linux kernel Netlink events for gateway and interfaces. These events are then sent to the Finit service monitor for services that may want to be SIGHUP'ed on new default route or interfaces going up/down.
-
resolvconf.so: Setup necessary files for
resolvconf
at startup. -
time.so: RFC 868 (rdate) plugin. Start as inetd service. Useful for testing inetd filtering — BusyBox has an rdate (TCP) client.
-
tty.so: Watches
/dev
, using inotify, for new device nodes (TTY's) to start/stop getty consoles on them on demand. Useful when plugging in a usb2serial converter to login to your embedded device. -
urandom.so: Setup random seed at startup.
-
x11-common.so: Setup necessary files for X-Window.
Usually you want to hook into the boot process once, simple hook plugins
like bootmisc.so
are great for that purpose. They are called at each
hook point in the boot process, useful to insert some pre-bootstrap
mechanisms, like generating configuration files, restoring HW device
state, etc. Available hook points are:
-
HOOK_ROOTFS_UP
: Whenfinit.conf
has been read and/
has is mounted — very early -
HOOK_BASEFS_UP
: All of/etc/fstab
is mounted, swap is available and default init signals are setup -
HOOK_NETWORK_UP
: System bootstrap, runlevel S, has completed and networking is up (lo
is up and thenetwork
script has run) -
HOOK_SVC_UP
: All services in the active runlevel has been launched -
HOOK_SYSTEM_UP
: All services and everything in/etc/finit.d
has been launched
-
HOOK_SVC_RECONF
: Called when the user has changed something in the/etc/finit.d
directory and issuedSIGHUP
. The hook is called when all modified/removed services have been stopped. When the hook has completed, Finit continues to start all modified and new services. -
HOOK_RUNLEVEL_CHANGE
: Called when the user has issued a runlevel change. The hook is called when services not matching the new runlevel have been been stopped. When the hook has completed, Finit continues to start all services in the new runlevel.
HOOK_SHUTDOWN
: Called at shutdown/reboot, right before all services are sentSIGTERM
Plugins like initctl.so
and tty.so
extend finit by acting on events,
they are called I/O plugins and are called from the finit main loop when
poll()
detects an event. See the source code for plugins/*.c
for
more help and ideas.
Callback plugins are called by finit right before a process is started,
or restarted if it exits. The callback runs as a separate process and
receives a pointer to the svc_t
of the service, with all command line
parameters free to modify as needed.
All the callback needs to do is respond with one of: SVC_STOP (0)
tells Finit to not start the service, SVC_START (1)
to start the
service, or SVC_RELOAD (2)
to have finit signal the process with
SIGHUP
.
Finit handles SIGUSR1
and SIGUSR2
for reboot and halt, and listens
to /dev/initctl
so system reboot and halt commands also work. The
latter is implemented in the optional initctl.so
plugin and can be
accessed with the traditional telinit
command line tool, symlinked to
finit
. Hence, if finit is your system init, then init q
will work
as the UNIX beards intended.
~ $ telinit
Usage: telinit [OPTIONS] [q | Q | 0-9]
Options:
-h, --help This help text
-v, --version Show Finit version
Commands:
q | Q Reload *.conf in /etc/finit.d/, like SIGHUP
0 - 9 Change runlevel: 0 halt, 6 reboot
Finit also implements a more modern API to query status, and start/stop
services, called initctl
. Unlike telinit
the initctl
tool does
not return until the given command has fully completed.
~ $ initctl -h
Usage: initctl [OPTIONS] <COMMAND>
Options:
-d, --debug Debug initctl (client)
-v, --verbose Verbose output
-h, --help This help text
Commands:
debug Toggle Finit (daemon) debug
help This help text
emit <EV> Emit event; a predefined event: RELOAD, STOP, START
or a custom string matching an event in a service
stanza, e.g: GW:UP, IFUP:IFNAME, IFDN:IFNAME. Where
IFNAME is the interface name, e.g. eth0
reload Reload *.conf in /etc/finit.d/ and activate changes
runlevel [0-9] Show or set runlevel: 0 halt, 6 reboot
status | show Show status of services
start <JOB|NAME>[:ID] Start service by job# or name, with optional ID
stop <JOB|NAME>[:ID] Stop/Pause a running service by job# or name
restart <JOB|NAME>[:ID] Restart (stop/start) service by job# or name
reload <JOB|NAME>[:ID] Reload (SIGHUP) service by job# or name
version Show Finit version
The emit <EV>
command can be used to send events to Finit. Built-in
events are: RELOAD, STOP, START. These events act on a lower level than
their command counterparts. The reload
command reloads all *.conf
files in /etc/finit.d/
and activates the changes, with emit RELOAD
only the *.conf
files are reloaded.
Note: The emit STOP
event is more like "prepare" than "stop".
Depending on how the service is declared, <!>
or not, the service
may be stopped, or skipped to be be sent SIGHUP
later when emit START
is issued.
To achieve the same result as initctl reload
emit all three events:
~ $ initctl emit "RELOAD,STOP,START"
On an embedded system this can be used when changing complete system
configuration. Between STOP
and START
reset/change any hardware
or kernel settings required to be in effect before new services are
started.
# 1. Update/Change/Generate all daemon configuration files
~ $ …
# 2. Update /etc/finit.d/*.conf
~ $ …
# 3. Prepare finit, stop all old/previous services
~ $ initctl emit "RELOAD,STOP"
# 4. Reconfigure hardware, interfaces/bridges/VLANs, etc.
~ $ brctl …
~ $ vconfig …
~ $ ifconfig …
# 5. Complete finit reload by starting all new services and
# SIGHUP any changed services
~ $ initctl emit "START"
The emit <EV>
command can also be used to emit custom events. In
fact, the event is a simple string. Declare a list of events in a
service stanza: service … <GW:UP,IFUP:eth0>
to reload (SIGHUP
) a
service when recieving the "GW:UP"
or "IFUP:eth0"
strings. If a
service cannot handle reload and must be stopped-started, simply add an
exclamation mark first: service … <!GW:UP,IFUP:eth0>
.
The <!>
notation to a service stanza can be used empty, then it will
apply to reload
and runlevel
commands. I.e., when a service's
.conf
file has been changed Finit will stop and start it instead. If
a service does not have <!>
declared, the service will be reloaded
(SIGHUP
:ed) in the START
phase instead. The latter is the preferred
behaviour, but not all daemons support this, unfortunately.
Note: even though it is possible to start services not belonging to the current runlevel these services will not be respawned automatically by Finit if they exit (crash). Hence, if the runlevel is 2, the below Dropbear SSH service will not be restarted if it, for some reason, exits.
~ $ initctl status -v
1 running 476 [S12345] /sbin/watchdog -T 16 -t 2 -F /dev/watchdog
2 running 477 [S12345] /sbin/syslogd -n -b 3 -D
3 running 478 [S12345] /sbin/klogd -n
4:1 inetd 0 [2345] internal time allow *:37
4:2 inetd 0 [2345] internal time allow *:37
4:3 inetd 0 [2345] internal 3737 allow *:3737
5:1 inetd 0 [2345] /sbin/telnetd allow *:23 deny eth0,eth1
5:2 inetd 0 [2345] /sbin/telnetd allow eth0:2323,eth2:2323,eth1:2323
6:1 inetd 0 [345] /sbin/dropbear allow eth0:222
6:2 inetd 0 [345] /sbin/dropbear allow *:22 deny eth0
Finit comes with a lightweight configure script to control which features to enable an plugins to build. Below are a few of the main switches to configure:
-
--prefix=
: Base prefix path for all files, except--sbindir
and--sysconfdir
. Used in concert with theDESTDIR
variable.Defaults to
/usr
. -
--sbindir=
: Path to where resulting binaries should install to. Used in concert with theDESTDIR
variable.Defaults to
/sbin
. -
--sysconfdir=
: Path to where finit configuration files should install to. Used in concert with theDESTDIR
variable.Defaults to
/etc
, but is currently unused. -
--plugindir=
: Absolute path to where finit should search for dynamically loadable plugins at runtime. Can also be controlled with the--libdir
switch.Defaults to
/lib/finit/plugins
. -
--with-plugins=
: List of stock finit plugins to build and install. The build system adds.o
or.so
extension to the listed plugins depending on the--enable-static
switch. Hence, list the plugins without their extension. -
--enable-embedded
: Target finit for BusyBox getty and mdev instead of a standard Linux distribution with GNU tools and udev. -
--enable-debug
: Add GDB symbols and disable code optimization. -
--enable-static
: Build Finit statically. The plugins will be built-in (.o files) instead. Note: very untested and not all plugins can be built static. It is recommended to use--with-plugins
and select only the plugins really needed. -
--disable-inetd
: Disables the built-in inetd server.
The following environment variables are checked by the makefiles and control what is built and where resulting binaries are installed.
-
ROOTDIR=
: Top directory for building complete system, used in pretty printing at build time. -
VERSION=
: Defaults to the currently released version of finit, e.g., 1.3 but can be overridden by packagers using this variable to add a suffix or completely alter the version. -
CFLAGS=
: DefaultCFLAGS
are inherited from the environment. -
CPPFLAGS=
: DefaultCPPFLAGS
are inherited from the environment. -
LDFLAGS=
: DefaultLDFLAGS
are inherited from the environment. -
LDLIBS=
: DefaultLIBLIBS
are inherited from the environment. -
DESTDIR=
: Used by packagers and distributions when building a relocatable bundle of files. Always prepended to theprefix
destination directory.
Example
First, unpack the archive:
$ tar xfJ finit-1.13.tar.xz
$ cd finit-1.13/
Then configure, build and install:
$ ./configure --with-plugins="initctl hwclock"
$ make
CC finit.o
CC conf.o
CC helpers.o
CC sig.o
CC svc.o
CC plugin.o
CC strlcpy.o
LINK finit
CC plugins/initctl.o
PLUGIN plugins/initctl.so
CC plugins/hwclock.o
PLUGIN plugins/hwclock.so
$
$ DESTDIR=/tmp/finit make install
INSTALL /tmp/finit/sbin/finit
INSTALL /tmp/finit/lib/finit/plugins/initctl.so
INSTALL /tmp/finit/lib/finit/plugins/hwclock.so
In this example the finit-1.13.tar.xz archive is unpacked to the
user's home directory, configured, built and installed to a temporary
staging directory. The environment variable DESTDIR
controls the
destination directory when installing, very useful for building binary
standalone packages.
To target an embedded Linux system, usally a system that use BusyBox tools instead of udev & C:o, add --enable-embedded to the configure command above.
For more configure flags, see ./configure --help
Note: If you run into problems starting Finit, take a look at
finit.c
. One of the most common problems is a custom Linux kernel
build that lack CONFIG_DEVTMPFS
. Another is too much cruft in the
system /etc/fstab
.
The default install does not setup finit as the system default
/sbin/init
, neither does it setup an initial /etc/finit.conf
.
It is assumed that users of finit are competent enough to either setup
finit as their default /sbin/init
or alter their respective Grub,
LOADLIN, LILO, U-Boot/Barebox or RedBoot boot loader configuration to
give the kernel the following extra command line:
init=/sbin/finit
Add finit_debug
, or --debug
, to the kernel command line to enable
debug messages. See the output from configure --help
for more on
how to assist debugging.
init=/sbin/finit --debug
This project is based on the original finit by Claudio Matsuoka which was reverse engineered from syscalls of the EeePC fastinit — "gaps filled with frog DNA …"
Finit is developed and maintained by Joachim Nilsson at GitHub. Please file bug reports, clone it, or send pull requests for bug fixes and proposed extensions.