diff options
Diffstat (limited to 'sys-utils/rdev.8')
| -rw-r--r-- | sys-utils/rdev.8 | 61 |
1 files changed, 27 insertions, 34 deletions
diff --git a/sys-utils/rdev.8 b/sys-utils/rdev.8 index 0cf83d365..98dce2b7f 100644 --- a/sys-utils/rdev.8 +++ b/sys-utils/rdev.8 @@ -3,31 +3,29 @@ .\" Changes from sct@dcs.ed.ac.uk added Sat Oct 9 09:54:00 1993. .TH RDEV 8 "20 November 1993" "Linux 0.99" "Linux Programmer's Manual" .SH NAME -rdev \- query/set image root device, swap device, RAM disk size, or video mode +rdev \- query/set image root device, RAM disk size, or video mode .SH SYNOPSIS .nf -.BR "rdev [ \-rsvh ] [ \-o " offset " ] [ " image " [ " value " [ " offset " ] ] ]" +.BR "rdev [ \-rvh ] [ \-o " offset " ] [ " image " [ " value " [ " offset " ] ] ]" .BR "rdev [ \-o " offset " ] [ " image " [ " root_device " [ " offset " ] ] ]" -.BR "swapdev [ \-o " offset " ] [ " image " [ " swap_device " [ " offset " ] ] ]" .BR "ramsize [ \-o " offset " ] [ " image " [ " size " [ " offset " ] ] ]" .BR "vidmode [ \-o " offset " ] [ " image " [ " mode " [ " offset " ] ] ]" .BR "rootflags [ \-o " offset " ] [ " image " [ " flags " [ " offset " ] ] ]" .fi .SH DESCRIPTION -.\" " for emacs hilit19 With no arguments, .B rdev outputs an .I /etc/mtab line for the current root file system. With no arguments, -.BR swapdev ", " ramsize ", " vidmode ", and " rootflags +.BR ramsize ", " vidmode ", and " rootflags print usage information. -In a bootable image for the Linux kernel, there are several pairs of bytes -which specify the root device, the video mode, the size of the RAM disk, -and the swap device. These pairs of bytes, by default, begin at offset 504 -(decimal) in the kernel image: +In a bootable image for the Linux kernel on i386, there are several pairs +of bytes which specify the root device, the video mode, and the size of +the RAM disk. These pairs of bytes, by default, begin +at offset 504 (decimal) in the kernel image: .nf .RS @@ -58,9 +56,9 @@ parameter, which is a bootable Linux kernel image, might be: .fi When using the -.BR rdev ", or " swapdev -commands, the -.IR root_device " or " swap_device +.B rdev +command, the +.I root_device parameter might be something like: .nf @@ -73,6 +71,10 @@ parameter might be something like: .RE .fi +One may also specify the device by a comma-separated pair +of decimal integers +.IR major , minor . + For the .B ramsize command, the @@ -114,12 +116,6 @@ is not specified, the will be examined to determine the current settings. .SH OPTIONS .TP -.B \-s -Causes -.B rdev -to act like -.BR swapdev . -.TP .B \-r Causes .B rdev @@ -141,23 +137,20 @@ to act like .B \-h Provides help. .SH BUGS -For historical reasons, there are two methods for specifying alternative -values for the offset. -.sp -The user interface is cumbersome, non-intuitive, and should probably be -re-written from scratch, allowing multiple kernel image parameters to be -changed or examined with a single command. -.sp -If LILO is used, -.B rdev -is no longer needed for setting the root device and the VGA mode, since -these parameters that -.B rdev -modifies can be set from the LILO prompt during a boot. However, +The .B rdev -is still needed at this time for setting the RAM disk size. Users are -encouraged to find the LILO documentation for more information, and to use -LILO when booting their systems. +utility, when used other than to find a name for the current root device, +is an ancient hack that works by patching a kernel image at a magic offset +with magic numbers. It does not work on architectures other than i386. +Its use is strongly discouraged. Use a boot loader like SysLinux or LILO +instead. +.SH HISTORY +At offset 502 there used to be the device number of the swap device +(in Linux 0.12), and "rdev -s" or "swapdev" would set this. +However, since Linux 0.95 this constant is not used any longer, +and the swap device is specified using the +.IR swapon () +system call. .SH AUTHORS .nf Originally by Werner Almesberger (almesber@nessie.cs.id.ethz.ch) |