From 46841acec337ada38be1852a648713f77bc5f226 Mon Sep 17 00:00:00 2001 From: Michael Kerrisk Date: Mon, 11 Sep 2017 07:40:23 +0200 Subject: [PATCH] sysfs.5: New page documenting the sysfs filesystem Just a skeleton page so far, but perhaps it will be filled out over time. Reported-by: Mark Wielaard Signed-off-by: Michael Kerrisk --- man5/sysfs.5 | 114 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) create mode 100644 man5/sysfs.5 diff --git a/man5/sysfs.5 b/man5/sysfs.5 new file mode 100644 index 000000000..0f1fd32df --- /dev/null +++ b/man5/sysfs.5 @@ -0,0 +1,114 @@ +.\" Copyright (c) 2017 by Michael Kerrisk +.\" +.\" %%%LICENSE_START(VERBATIM) +.\" Permission is granted to make and distribute verbatim copies of this +.\" manual provided the copyright notice and this permission notice are +.\" preserved on all copies. +.\" +.\" Permission is granted to copy and distribute modified versions of this +.\" manual under the conditions for verbatim copying, provided that the +.\" entire resulting derived work is distributed under the terms of a +.\" permission notice identical to this one. +.\" +.\" Since the Linux kernel and libraries are constantly changing, this +.\" manual page may be incorrect or out-of-date. The author(s) assume no +.\" responsibility for errors or omissions, or for damages resulting from +.\" the use of the information contained herein. The author(s) may not +.\" have taken the same level of care in the production of this manual, +.\" which is licensed free of charge, as they might when working +.\" professionally. +.\" +.\" Formatted or processed versions of this manual, if unaccompanied by +.\" the source, must acknowledge the copyright and authors of this work. +.\" %%%LICENSE_END +.\" +.TH SYSFS 5 2017-09-10 "Linux" "Linux Programmer's Manual" +.SH NAME +sysfs \- a filesystem for exporting kernel objects +.SH DESCRIPTION +The +.B sysfs +filesystem is a pseudo-filesystem which provides an interface to +kernel data structures. +(More precisely, the files and directories in +.B sysfs +provide a view of the +.IR kobject +structures defined internally within the kernel.) +The files under +.B sysfs +provide information about devices, kernel modules, filesystems, +and other kernel components. +.PP +The +.B sysfs +filesystem is commonly mounted at +.IR /sys . +Typically, it is mounted automatically by the system, +but it can also be mounted manually using a command such as: +.PP +.in +4n +.EX +mount \-t sysfs sysfs /sys +.EE +.in +.PP +Many of the files in the +.B sysfs +filesystem are read-only, +but some files are writable, allowing kernel variables to be changed. +.\" +.SS Files and directories +The following list describes some of the files and directories under the +.I /sys +hierarchy. +.TP +.IR /sys/block +.TP +.IR /sys/bus +.TP +.IR /sys/class +.TP +.IR /sys/dev +.TP +.IR /sys/devices +.TP +.IR /sys/firmware +.TP +.IR /sys/fs +.TP +.IR /sys/fs/cgroup +This directory conventionally is used as a mount point for a +.BR tmpfs (5) +filesystem containing mount points for +.BR cgroups (7) +filesystems. +.TP +.IR /sys/hypervisor +.TP +.IR /sys/kernel +.TP +.IR /sys/module +.TP +.IR /sys/power +.SH VERSIONS +The +.B sysfs +filesystem first appeared in Linux 2.6.0. +.SH CONFORMING TO +The +.B sysfs +filesystem is Linux-specific. +.SH NOTES +This manual page is incomplete, possibly inaccurate, and is the kind +of thing that needs to be updated very often. +.SH SEE ALSO +.BR proc (5), +.BR udev (7) +.PP +The kernel source file +.I Documentation/filesystems/sysfs.txt +and various other files in +.IR Documentation/ABI +and +.IR Documentation/*/sysfs.txt