.\" This man page written 950814 by aeb, based on Paul Gortmaker's HOWTO
.\" (dated v1.0.1, 15/08/95).
.\" Major update, aeb, 970114.
-.\" FIXME ? The use of quotes on this page is inconsistent with the
+.\" FIXME . The use of quotes on this page is inconsistent with the
.\" rest of man-pages.
.\"
-.TH BOOTPARAM 7 2013-06-08 "Linux" "Linux Programmer's Manual"
+.TH BOOTPARAM 7 2014-06-13 "Linux" "Linux Programmer's Manual"
.SH NAME
bootparam \- introduction to boot time parameters of the Linux kernel
.SH DESCRIPTION
if 'foo' was registered.
If it was, then it would call the setup
function associated with 'foo' (foo_setup()) and hand it the arguments
-3, 4, 5 and 6 as given on the kernel command line.
+3, 4, 5, and 6 as given on the kernel command line.
Anything of the form 'foo=bar' that is not accepted as a setup function
as described above is then interpreted as an environment variable to
.BR init (1)
installed on
your system to see what arguments it accepts.
-.SS General non-device specific boot arguments
+.SS General non-device-specific boot arguments
.TP
.B "'init=...'"
This sets the initial command to be executed by the kernel.
.TP
.B "'root=...'"
This argument tells the kernel what device is to be used as the root
-file system while booting.
+filesystem while booting.
The default of this setting is determined
at compile time, and usually is the value of the root device of the
system that the kernel was built on.
(The type nfs specifies a net boot; ram refers to a ram disk.)
Note that this has nothing to do with the designation of these
-devices on your file system.
+devices on your filesystem.
The '/dev/' part is purely conventional.
The more awkward and less portable numeric specification of the above
possible root devices in major/minor format is also accepted.
-(E.g.,
+(For example,
.I /dev/sda3
is major 8, minor 3, so you could use 'root=0x803' as an
alternative.)
.TP
+.BR "'rootdelay='"
+This parameter sets the delay (in seconds) to pause before attempting
+to mount the root filesystem.
+.TP
+.BR "'rootflags=...'"
+This parameter sets the mount option string for the root filesystem
+(see also
+.BR fstab (5)).
+.TP
.BR "'rootfstype=...'"
The 'rootfstype' option tells the kernel to mount the root filesystem as
if it where of the type specified.
need to boot the box from alternate media.
.TP
.BR 'ro' " and " 'rw'
-The 'ro' option tells the kernel to mount the root file system
-as 'read-only' so that file system consistency check programs (fsck)
-can do their work on a quiescent file system.
+The 'ro' option tells the kernel to mount the root filesystem
+as 'read-only' so that filesystem consistency check programs (fsck)
+can do their work on a quiescent filesystem.
No processes can
-write to files on the file system in question until it is 'remounted'
+write to files on the filesystem in question until it is 'remounted'
as read/write capable, for example, by 'mount \-w \-n \-o remount /'.
(See also
.BR mount (8).)
-The 'rw' option tells the kernel to mount the root file system read/write.
+The 'rw' option tells the kernel to mount the root filesystem read/write.
This is the default.
.TP
it is often useful to load the floppy contents into a
ramdisk.
One might also have a system in which first
-some modules (for file system or hardware) must be loaded
+some modules (for filesystem or hardware) must be loaded
before the main disk can be accessed.
In Linux 1.3.48, ramdisk handling was changed drastically.
a "normal" ramdisk, which is mounted read-write as root device;
then
.I /linuxrc
-is executed; afterward the "real" root file system is mounted,
-and the initrd file system is moved over to
+is executed; afterward the "real" root filesystem is mounted,
+and the initrd filesystem is moved over to
.IR /initrd ;
finally
the usual boot sequence (e.g., invocation of
LUNs not equal to zero.
Therefore, if the compile-time flag
.B CONFIG_SCSI_MULTI_LUN
-is not set, newer kernels will by default only probe LUN zero.
+is not set, newer kernels will by default probe only LUN zero.
To specify the number of probed LUNs at boot, one enters
\&'max_scsi_luns=n' as a boot arg, where n is a number between one and
.IP
The
.I mem_base
-value is the value of the memory mapped I/O region that
+value is the value of the memory-mapped I/O region that
the card uses.
This will usually be one of the following values:
0xc8000, 0xca000, 0xcc000, 0xce000, 0xdc000, 0xde000.
.IP
The
.I mem_base
-value is the value of the memory mapped I/O region that
+value is the value of the memory-mapped I/O region that
the card uses.
This will usually be one of the following values:
0xc8000, 0xca000, 0xcc000, 0xce000, 0xdc000, 0xde000.
geometry parameters of the second disk.
.TP
.B "XT Disk Driver Options ('xd=')"
-If you are unfortunate enough to be using one of these old 8 bit cards
-that move data at a whopping 125kB/s then here is the scoop.
+If you are unfortunate enough to be using one of these old 8-bit cards
+that move data at a whopping 125kB/s, then here is the scoop.
If the card is not recognized,
you will have to use a boot argument of the form:
.fi
.in
.IP
-If you set the magic_number to 0x79 then the driver will try and run
+If you set the magic_number to 0x79, then the driver will try and run
anyway in the event of an unknown firmware version.
All other values
are ignored.
All parameters except the last are integers;
the dummy 0 is required because of a bug in the setup code.
The mode parameter is a string with syntax hw:modem,
-where hw is one of sbc, wss, wssfdx and modem is one of
-afsk1200, fsk9600.
+where hw is one of sbc, wss, or wssfdx, and modem is one of
+afsk1200 or fsk9600.
.SS The line printer driver
.TP
.B "'lp='"
.\" .SH AUTHORS
.\" Linus Torvalds (and many others)
.SH SEE ALSO
-.BR lilo.conf (5),
.BR klogd (8),
-.BR lilo (8),
.BR mount (8)
Large parts of this man page have been derived from the
More information may be found in this (or a more recent) HOWTO.
An up-to-date source of information is the kernel source file
.IR Documentation/kernel-parameters.txt .
+.SH COLOPHON
+This page is part of release 3.79 of the Linux
+.I man-pages
+project.
+A description of the project,
+information about reporting bugs,
+and the latest version of this page,
+can be found at
+\%http://www.kernel.org/doc/man\-pages/.