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Per-image options for kernels

 

Each (kernel or non-kernel) image description begins with a special variable (see section 3.3) which is followed by optional variables. The following variables can be used for all image descriptions that describe a Linux kernel:

append= string
Appends the options specified in string to the parameter line passed to the kernel. This is typically used to specify parameters of hardware that can't be entirely auto-detected, e.g.
literal= string
Like append, but removes all other options (e.g. setting of the root device). Because vital options can be removed unintentionally with literal, this option cannot be set in the global options section.
ramdisk= size
specifies the size of the optional RAM disk. A value of zero indicates that no RAM disk should be created. If this variable is omitted, the RAM disk size configured into the boot image is used.
read-only
specifies that the root file system should be mounted read-only. Typically, the system startup procedure re-mounts the root file system read-write later (e.g. after fsck'ing it).
read-write
specifies that the root file system should be mounted read-write.
root= root_device
specifies the device that should be mounted as root. If the special name current is used, the root device is set to the device on which the root file system is currently mounted. If the root has been changed with -r, the respective device is used. If the variable root is omitted, the root device setting contained in the kernel image is used. It can be changed with the rdev program.
vga= mode
  specifies the VGA text mode that should be selected when booting. The following values are recognized (case is ignored):
normal
select normal 80x25 text mode.
extended
select 80x50 text mode. The word extended can be abbreviated to ext.
ask
stop and ask for user input (at boot time).
number
use the corresponding text mode. A list of available modes can be obtained by booting with vga=ask and pressing Enter.

If this variable is omitted, the VGA mode setting contained in the kernel image is used. rdev supports manipulation of the VGA text mode setting in the kernel image.

If one of ramdisk, read-only, read-write, root, or vga is omitted in the configuration file and the corresponding value in the kernel image is changed, LILO or the kernel will use the new value.

It is perfectly valid to use different settings for the same image, because LILO stores them in the image descriptors and not in the images themselves.

Example:

image = /vmlinuz
  label = lin-hd
  root = /dev/hda2
image = /vmlinuz
  label = lin-fd
  root = /dev/fd0



next up previous contents
Next: Boot image types Up: Configuration Previous: General per-image options



Ross Biro
Sat May 20 13:51:22 PDT 1995