Index: init.8
===================================================================
--- init.8 (nonexistent)
+++ init.8 (revision 5)
@@ -0,0 +1,353 @@
+'\" -*- coding: UTF-8 -*-
+.\" Copyright (C) 1998-2004 Miquel van Smoorenburg.
+.\"
+.\" This program is free software; you can redistribute it and/or modify
+.\" it under the terms of the GNU General Public License as published by
+.\" the Free Software Foundation; either version 2 of the License, or
+.\" (at your option) any later version.
+.\"
+.\" This program is distributed in the hope that it will be useful,
+.\" but WITHOUT ANY WARRANTY; without even the implied warranty of
+.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+.\" GNU General Public License for more details.
+.\"
+.\" You should have received a copy of the GNU General Public License
+.\" along with this program; if not, write to the Free Software
+.\" Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+.\"
+.\"{{{}}}
+.\"{{{ Title
+.TH INIT 8 "29 Jul 2004" "" "Linux System Administrator's Manual"
+.\"}}}
+.\"{{{ Name
+.SH NAME
+init, telinit \- process control initialization
+.\"}}}
+.\"{{{ Synopsis
+.SH SYNOPSIS
+.B /sbin/init
+.RB [ " -a " ]
+.RB [ " -s " ]
+.RB [ " -b " ]
+[ \fB\-z\fP \fIxxx\fP ]
+.RB [ " 0123456Ss " ]
+.br
+.B /sbin/init
+.RB [ " --version " ]
+.br
+.B /sbin/telinit
+[ \fB\-t\fP \fISECONDS\fP ]
+.RB [ " 0123456sSQqabcUu " ]
+.br
+.B /sbin/telinit
+[ \fB\-e\fP \fIVAR\fP[\fB=\fP\fIVAL\fP] ]
+.\"}}}
+.\"{{{ Description
+.SH DESCRIPTION
+.\"{{{ init
+.SS Init
+.B Init
+is the parent of all processes. Its primary role is to create processes
+from a script stored in the file \fB/etc/inittab\fP (see
+\fIinittab\fP(5)). This file usually has entries which cause \fBinit\fP
+to spawn \fBgetty\fPs on each line that users can log in. It also
+controls autonomous processes required by any particular system.
+.PP
+.\"{{{ Runlevels
+.SH RUNLEVELS
+A \fIrunlevel\fP is a software configuration of the system which allows
+only a selected group of processes to exist. The processes spawned by
+\fBinit\fP for each of these runlevels are defined in the
+\fB/etc/inittab\fP file. \fBInit\fP can be in one of eight runlevels:
+\fB0\(en6\fP and \fBS\fP (a.k.a. \fBs\fP). The runlevel is
+changed by having a privileged user run \fBtelinit\fP, which sends
+appropriate signals to \fBinit\fP, telling it which runlevel to change
+to.
+.PP
+Runlevels \fBS\fP, \fB0\fP, \fB1\fP, and \fB6\fP are reserved.
+Runlevel S is used to initialize the system on boot.
+When starting runlevel S (on boot)
+or runlevel 1 (switching from a multi-user runlevel)
+the system is entering ``single-user mode'', after which the
+current runlevel is S.
+Runlevel 0 is used to halt the system;
+runlevel 6 is used to reboot the system.
+.PP
+After booting through S the system automatically enters one of
+the multi-user runlevels 2 through 5, unless there was some
+problem that needs to be fixed by the administrator in
+single-user mode.
+Normally after entering single-user mode
+the administrator performs maintenance and then reboots the system.
+.PP
+For more information,
+see the manpages for \fBshutdown\fP(8) and \fBinittab\fP(5).
+.PP
+Runlevels 7-9 are also valid, though not really documented. This is
+because "traditional" Unix variants don't use them.
+.PP
+Runlevels \fIS\fP and \fIs\fP are the same.
+Internally they are aliases for the same runlevel.
+.\"}}}
+.PP
+.SH BOOTING
+After \fBinit\fP is invoked as the last step of the kernel boot sequence,
+it looks for the file \fB/etc/inittab\fP to see if there is an entry of the
+type \fBinitdefault\fP (see \fIinittab\fP(5)). The \fBinitdefault\fP entry
+determines the initial runlevel of the system. If there is no such
+entry (or no \fB/etc/inittab\fP at all), a runlevel must be
+entered at the system console.
+.PP
+Runlevel \fBS\fP or \fBs\fP initialize the system
+and do not require an \fB/etc/inittab\fP file.
+.PP
+In single user mode, \fB/sbin/sulogin\fP is invoked on \fB/dev/console\fP.
+.PP
+When entering single user mode, \fBinit\fP initializes the consoles
+\fBstty\fP settings to sane values. Clocal mode is set. Hardware
+speed and handshaking are not changed.
+.PP
+When entering a multi-user mode for the first time, \fBinit\fP performs the
+\fBboot\fP and \fBbootwait\fP entries to allow file systems to be
+mounted before users can log in. Then all entries matching the runlevel
+are processed.
+.PP
+When starting a new process, \fBinit\fP first checks whether the file
+\fI/etc/initscript\fP exists. If it does, it uses this script to
+start the process.
+.PP
+Each time a child terminates, \fBinit\fP records the fact and the reason
+it died in \fB/var/run/utmp\fP and \fB/var/log/wtmp\fP,
+provided that these files exist.
+.SH CHANGING RUNLEVELS
+After it has spawned all of the processes specified, \fBinit\fP waits
+for one of its descendant processes to die, a powerfail signal, or until
+it is signaled by \fBtelinit\fP to change the system's runlevel.
+When one of the above three conditions occurs, it re-examines
+the \fB/etc/inittab\fP file. New entries can be added to this file at
+any time. However, \fBinit\fP still waits for one of the above three
+conditions to occur. To provide for an instantaneous response, the
+\fBtelinit Q\fP or \fBq\fP command can wake up \fBinit\fP to re-examine (reload) the
+\fB/etc/inittab\fP file.
+.PP
+If \fBinit\fP is not in single user mode and receives a powerfail
+signal (SIGPWR), it reads the file \fB/etc/powerstatus\fP. It then starts
+a command based on the contents of this file:
+.IP F(AIL)
+Power is failing, UPS is providing the power. Execute the \fBpowerwait\fP
+and \fBpowerfail\fP entries.
+.IP O(K)
+The power has been restored, execute the \fBpowerokwait\fP entries.
+.IP L(OW)
+The power is failing and the UPS has a low battery. Execute the
+\fBpowerfailnow\fP entries.
+.PP
+If /etc/powerstatus doesn't exist or contains anything else then the
+letters \fBF\fP, \fBO\fP or \fBL\fP, init will behave as if it has read
+the letter \fBF\fP.
+.PP
+Usage of \fBSIGPWR\fP and \fB/etc/powerstatus\fP is discouraged. Someone
+wanting to interact with \fBinit\fP should use the \fB/dev/initctl\fP
+control channel - see the initctl manual page for more documentation
+about this.
+.PP
+When \fBinit\fP is requested to change the runlevel, it sends the
+warning signal \s-1\fBSIGTERM\fP\s0 to all processes that are undefined
+in the new runlevel. It then waits 3 seconds before forcibly
+terminating these processes via the \s-1\fBSIGKILL\fP\s0 signal.
+Note that \fBinit\fP assumes that all these processes (and their
+descendants) remain in the same process group which \fBinit\fP
+originally created for them. If any process changes its process group
+affiliation it will not receive these signals. Such processes need to
+be terminated separately.
+.\"}}}
+.\"{{{ telinit
+.SH TELINIT
+\fB/sbin/telinit\fP is linked to \fB/sbin/init\fP. It takes a
+one-character argument and signals \fBinit\fP to perform the appropriate
+action. The following arguments serve as directives to
+\fBtelinit\fP:
+.IP "\fB0\fP,\fB1\fP,\fB2\fP,\fB3\fP,\fB4\fP,\fB5\fP or \fB6\fP"
+tell \fBinit\fP to switch to the specified run level.
+.IP \fBa\fP,\fBb\fP,\fBc\fP
+tell \fBinit\fP to process only those \fB/etc/inittab\fP file
+entries having runlevel \fBa\fP,\fBb\fP or \fBc\fP.
+.IP "\fBQ\fP or \fBq\fP"
+tell \fBinit\fP to re-examine the \fB/etc/inittab\fP file.
+.IP "\fBS\fP or \fBs\fP"
+tell \fBinit\fP to switch to single user mode.
+.IP "\fBU\fP or \fBu\fP"
+tell \fBinit\fP to re-execute itself (preserving the state). No re-examining of
+\fB/etc/inittab\fP file happens. Runlevel should be one of
+\fBSs0123456\fP
+otherwise request would be silently ignored.
+.PP
+\fBtelinit\fP can tell \fBinit\fP how long it should wait
+between sending processes the SIGTERM and SIGKILL signals. The default
+is 3 seconds, but this can be changed with the \fB-t\fP option.
+.PP
+\fBtelinit -e\fP tells \fBinit\fP to change the environment
+for processes it spawns.
+The argument of \fB-e\fP is either of the form \fIVAR\fP=\fIVAL\fP
+which sets variable \fIVAR\fP to value \fIVAL\fP,
+or of the form \fIVAR\fP
+(without an equality sign)
+which unsets variable \fIVAR\fP.
+.PP
+\fBtelinit\fP can be invoked only by users with appropriate
+privileges.
+.PP
+The \fBinit\fP binary checks if it is \fBinit\fP or \fBtelinit\fP by looking
+at its \fIprocess id\fP; the real \fBinit\fP's process id is always \fB1\fP.
+From this it follows that instead of calling \fBtelinit\fP one can also
+just use \fBinit\fP instead as a shortcut.
+.\"}}}
+.\"}}}
+.SH ENVIRONMENT
+\fBInit\fP sets the following environment variables for all its children:
+.IP \fBPATH\fP
+\fI/bin:/usr/bin:/sbin:/usr/sbin\fP
+.IP \fBINIT_VERSION\fP
+As the name says. Useful to determine if a script runs directly from \fBinit\fP.
+.IP \fBRUNLEVEL\fP
+The current system runlevel.
+.IP \fBPREVLEVEL\fP
+The previous runlevel (useful after a runlevel switch).
+.IP \fBCONSOLE\fP
+The system console. This is really inherited from the kernel; however
+if it is not set \fBinit\fP will set it to \fB/dev/console\fP by default.
+.SH BOOTFLAGS
+It is possible to pass a number of flags to \fBinit\fP from the
+boot monitor (eg. LILO or GRUB). \fBInit\fP accepts the following flags:
+.TP 0.5i
+.B -s, S, single
+Single user mode boot. In this mode \fI/etc/inittab\fP is
+examined and the bootup rc scripts are usually run before
+the single user mode shell is started.
+.PP
+.TP 0.5i
+.B 1-5
+Runlevel to boot into.
+.PP
+.TP 0.5i
+.B -b, emergency
+Boot directly into a single user shell without running any
+other startup scripts.
+.PP
+.TP 0.5i
+.B -a, auto
+The LILO boot loader adds the word "auto" to the command line if it
+booted the kernel with the default command line (without user intervention).
+If this is found \fBinit\fP sets the "AUTOBOOT" environment
+variable to "yes". Note that you cannot use this for any security
+measures - of course the user could specify "auto" or \-a on the
+command line manually.
+.PP
+.TP 0.5i
+.BI "-z " xxx
+The argument to \fB-z\fP is ignored. You can use this to expand the command
+line a bit, so that it takes some more space on the stack. \fBInit\fP
+can then manipulate the command line so that \fBps\fP(1) shows
+the current runlevel.
+.PP
+.TP 0.5i
+.B \-\-version
+This argument, when used on its own, displays the current version of init
+to the console/stdout. It is a quick way to determine which init software and
+version is being used. After the version information is displayed, init
+immediately exits with a return code of zero.
+.PP
+.SH INTERFACE
+Init listens on a \fIfifo\fP in /dev, \fI/dev/initctl\fP, for messages.
+\fBTelinit\fP uses this to communicate with init. The interface is not
+very well documented or finished. Those interested should study the
+\fIinitreq.h\fP file in the \fIsrc/\fP subdirectory of the \fBinit\fP
+source code tar archive.
+.SH SIGNALS
+Init reacts to several signals:
+.TP 0.5i
+.B SIGHUP
+Has the same effect as \fBtelinit q\fP.
+.PP
+.TP 0.5i
+.B SIGUSR1
+On receipt of this signals, init closes and re-opens its control fifo,
+\fB/dev/initctl\fP. Useful for bootscripts when /dev is remounted.
+.TP 0.5i
+.B SIGUSR2
+When init receives SIGUSR2, init closes and leaves the control fifo,
+\fB/dev/initctl\fP, closed. This may be used to make sure init is not
+holding open any files. However, it also prevents init from switching
+runlevels. Which means commands like shutdown no longer work.
+The fifo can be re-opened by sending init the SIGUSR1 signal.
+.TP 0.5i
+.B SIGINT
+Normally the kernel sends this signal to init when CTRL-ALT-DEL is
+pressed. It activates the \fIctrlaltdel\fP action.
+.TP 0.5i
+.B SIGWINCH
+The kernel sends this signal when the \fIKeyboardSignal\fP key is hit.
+It activates the \fIkbrequest\fP action.
+\"{{{ Conforming to
+.SH CONFORMING TO
+\fBInit\fP is compatible with the System V init. It works closely
+together with the scripts in the directories
+\fI/etc/init.d\fP and \fI/etc/rc{runlevel}.d\fP.
+If your system uses this convention, there should be a \fIREADME\fP
+file in the directory \fI/etc/init.d\fP explaining how these scripts work.
+.\"}}}
+.\"{{{ Files
+.SH FILES
+.nf
+/etc/inittab
+/etc/initscript
+/dev/console
+/var/run/utmp
+/var/log/wtmp
+/dev/initctl
+.fi
+.\"}}}
+.\"{{{ Warnings
+.SH WARNINGS
+\fBInit\fP assumes that processes and descendants of processes
+remain in the same process group which was originally created
+for them. If the processes change their group, \fBinit\fP can't
+kill them and you may end up with two processes reading from one
+terminal line.
+.PP
+On a Debian system, entering runlevel 1 causes all processes
+to be killed except for kernel threads and the script that does
+the killing and other processes in its session.
+As a consequence of this, it isn't safe to return from runlevel 1
+to a multi-user runlevel: daemons that were started in runlevel S
+and are needed for normal operation are no longer running.
+The system should be rebooted.
+.\"}}}
+.\"{{{ Diagnostics
+.SH DIAGNOSTICS
+If \fBinit\fP finds that it is continuously respawning an entry
+more than 10 times in 2 minutes, it will assume that there is an error
+in the command string, generate an error message on the system console,
+and refuse to respawn this entry until either 5 minutes has elapsed or
+it receives a signal. This prevents it from eating up system resources
+when someone makes a typographical error in the \fB/etc/inittab\fP file
+or the program for the entry is removed.
+.\"}}}
+.\"{{{ Author
+.SH AUTHOR
+Miquel van Smoorenburg (miquels@cistron.nl), initial manual
+page by Michael Haardt (u31b3hs@pool.informatik.rwth-aachen.de).
+.\"}}}
+.\"{{{ See also
+.SH "SEE ALSO"
+.BR getty (1),
+.BR login (1),
+.BR sh (1),
+.BR runlevel (8),
+.BR shutdown (8),
+.BR kill (1),
+.BR initctl (5),
+.BR inittab (5),
+.BR initscript (5),
+.BR utmp (5)
+.\"}}}
Index: initctl.5
===================================================================
--- initctl.5 (nonexistent)
+++ initctl.5 (revision 5)
@@ -0,0 +1,148 @@
+'\" -*- coding: UTF-8 -*-
+.\" Copyright (C) 2018 Jesse Smith
+.\"
+.\" This program is free software; you can redistribute it and/or modify
+.\" it under the terms of the GNU General Public License as published by
+.\" the Free Software Foundation; either version 2 of the License.
+.\"
+.\" This program is distributed in the hope that it will be useful,
+.\" but WITHOUT ANY WARRANTY; without even the implied warranty of
+.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+.\" GNU General Public License for more details.
+.\"
+.\" You should have received a copy of the GNU General Public License
+.\" along with this program; if not, write to the Free Software
+.\" Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+.\"
+.TH INITCTL 5 "April 13, 2018" "" "Linux System Administrator's Manual"
+.SH NAME
+initctl \- /dev/initctl is a named pipe which passes commands to SysV init.
+.SH SYNOPSIS
+/dev/initctl
+.SH DESCRIPTION
+
+This document describes the communiction pipe set up by SysV init
+at /dev/initctl. This named pipe allows programs with the proper
+permissions (typically programs run by root have read+write access to
+the pipe) to send signals to the init program (PID 1).
+
+The init manual page has, up until recently, simply stated
+that people wishing to understand how to send messages to init
+should read the init program's source code, but that is not usually practical.
+
+Messages sent to the pipe to talk to init must have a special format.
+This format is defined as a C structure and the technical break-down
+is presented here:
+
+/*
+ * Because of legacy interfaces, "runlevel" and "sleeptime"
+ * aren't in a separate struct in the union.
+ *
+ * The weird sizes are because init expects the whole
+ * struct to be 384 bytes.
+ */
+
+struct init_request {
+ int magic; /* Magic number */
+ int cmd; /* What kind of request */
+ int runlevel; /* Runlevel to change to */
+ int sleeptime; /* Time between TERM and KILL */
+ union {
+ struct init_request_bsd bsd;
+ char data[368];
+ } i;
+};
+
+
+Let's go through the init_request structure one line at a time. The
+first variable, the "magic" number must be of the value 0x03091969.
+The init program then knows that only programs with root access which send
+this magic number are authorized to communicate with init.
+
+The cmd variable is a value in the range of 0-8 (currently). This cmd
+variable tells init what we want it to do. Here are the possible options:
+
+1 - Set the current runlevel, specified by the runlevel variable.
+
+2 - The power will fail soon (probably low battery) prepare to shutdown.
+
+3 - The power is failing, do shutdown immediately.
+
+4 - The power is okay, cancel shutdown.
+
+6 - Set an environment variable to a value to be specified in
+ the data variable of this structure.
+
+Other cmd options may be added to init later. For example, command values
+0, 5 and 7 are defined but currently not implemented.
+
+The runlevel variable will specify the runlevel to switch to (0-6).
+
+The sleeptime variable is to be used when we want to tell init to change
+the time spent waiting between sending SIGTERM and SIGKILL during the
+shutdown process. Changing this at run time is not yet implemented.
+
+The data variable (in the union) can be used to pass misc data which init
+might need to process our request. For example, when setting environment
+variables.
+
+When setting an environment variable through init's /dev/initctl pipe,
+the data variable should have the format VARIABLE=VALUE. The string
+should be terminated with a NULL character.
+
+.SH EXAMPLES
+
+The following C code example shows how to send a set environment variable
+request to the init process using the /dev/initctl pipe. This example
+is simplified and skips the error checking. A more comlpete example can be
+found in the shutdown.c program's init_setnv() function.
+
+.nf
+struct init_request request; /* structure defined above */
+int fd; /* file descriptor for pipe */
+
+memset(&request, 0, sizeof(request)); /* initialize structure */
+request.magic = 0x03091969; /* magic number required */
+request.cmd = 6; /* 6 is to set a variable */
+sprintf(request.data, "VARIABLE=VALUE"); /* set VAR to VALUE in init */
+
+if ((fd = open(INIT_FIFO, O_WRONLY)) >= 0) /* open pipe for writing */
+{
+ size_t s = sizeof(request); /* size of structure to write */
+ void *ptr = &request; /* temporary pointer */
+ write(fd, ptr, s); /* send structure to the pipe */
+ close(fd); /* close the pipe when done */
+}
+.fi
+
+.sp
+.SH NOTES
+Usually the /dev/initctl pipe would only be used by low-level programs to
+request a power-related shutdown or change the runlevel, like telinit
+would do. Most of the time there is no need to talk to init directly, but
+this gives us an extenable approach so init can be taught how to learn
+more commands.
+.PP
+The commands passed through the /dev/initctl pipe must be sent in a specific
+binary format and be of a specific length. Larger data structures or ones
+not using the proper format will be ignored. Typically, only root has the
+ability to write to the initctl pipe for security reasons.
+.PP
+The /dev/initctl pipe can be closed by sending init (PID 1) the SIGUSR2
+signal. This closes the pipe and leaves it closed. This may be useful
+for making sure init is not keeping any files open. However, when the
+pipe is closed, init no longer receives signals, such as those sent by
+shutdown or telinit. In other words if we close the pipe, init cannot
+change its runlevel directly. The pipe may be re-opened by sending init (PID 1)
+the SIGUSR1 signal.
+.PP
+If the /dev/initctl pipe is closed then it may still be possible to bring
+down the system using the shutdown command's -n flag, but this is not
+always clean and not recommended.
+.SH FILES
+/dev/initctl
+/sbin/init
+.SH AUTHOR
+Jesse Smith <jsmith@resonatingmedia.com>
+.SH "SEE ALSO"
+init(8)
Index: .
===================================================================
--- . (nonexistent)
+++ . (revision 5)
Property changes on: .
___________________________________________________________________
Added: svn:ignore
## -0,0 +1,73 ##
+
+# install dir
+dist
+
+# Target build dirs
+.a1x-newlib
+.a2x-newlib
+.at91sam7s-newlib
+
+.build-machine
+
+.a1x-glibc
+.a2x-glibc
+.h3-glibc
+.h5-glibc
+.i586-glibc
+.i686-glibc
+.imx6-glibc
+.jz47xx-glibc
+.makefile
+.am335x-glibc
+.omap543x-glibc
+.p5600-glibc
+.power8-glibc
+.power8le-glibc
+.power9-glibc
+.power9le-glibc
+.m1000-glibc
+.riscv64-glibc
+.rk328x-glibc
+.rk33xx-glibc
+.rk339x-glibc
+.s8xx-glibc
+.s9xx-glibc
+.x86_64-glibc
+
+# Hidden files (each file)
+.makefile
+.dist
+.rootfs
+
+# src & hw requires
+.src_requires
+.src_requires_depend
+.requires
+.requires_depend
+
+# Tarballs
+*.gz
+*.bz2
+*.lz
+*.xz
+*.tgz
+*.txz
+
+# Signatures
+*.asc
+*.sig
+*.sign
+*.sha1sum
+
+# Patches
+*.patch
+
+# Descriptions
+*.dsc
+*.txt
+
+# Default linux config files
+*.defconfig
+
+# backup copies
+*~
Radix cross Linux
The main Radix cross Linux repository contains the build scripts of packages, which have the most complete and common functionality for desktop machines
452 Commits
2 Branches
1 Tag