rdev

rdev [options] [image [value [offset]]]

System administration command. If invoked with no arguments, show the current root filesystem in /etc/mtab syntax. Otherwise, change the values in the kernel image that specify the RAM disk size (by default located at decimal byte offset 504 in the kernel), VGA mode (default 506), and root device (default 508). You must specify the kernel image to be changed, and may specify a new value and a different offset. Using rdev to change these values directly in an image file is discouraged. These values can all be set by a boot loader such as lilo or grub.