I haven't tried this yet but according to the grub info pages you should
be able to redirect the output to serial port. I used 'pinfo grub' to
obtain the following:
"Using GRUB via a serial line
If you have many computers or computers with no display/keyboard, it
would be very useful to control the computers with serial
communications. To connect a computer with another via a serial line,
you need to prepare a null-modem (cross) serial cable, and you may need
to have multiport serial boards, if your computer doesn't have extra
serial ports. In addition, a terminal emulator is also required, such as
minicom. Refer to a manual of your operating system, for more
information.
As for GRUB, the instruction to set up a serial terminal is quite
simple. First of all, make sure that you haven't specified the option
`--disable-serial' to the configure script when you built your GRUB
images. If you get them in binary form, probably they have serial
terminal support already.
Then, initialize your serial terminal after GRUB starts up. Here is
an example:
grub> serial --unit=0 --speed=9600
grub> terminal serial
The command `serial' initializes the serial unit 0 with the speed
9600bps. The serial unit 0 is usually called `COM1', so, if you want to
use COM2, you must specify `--unit=1' instead. This command accepts
many other options, so please refer to *Note serial::, for more details.
The command `terminal' (*note terminal::) chooses which type of
terminal you want to use. In that case above, the terminal will be a
serial terminal, but you can also pass `console' to the command, like
`terminal serial console'. In this case, a terminal in which you press
any key will be selected as a GRUB terminal.
However, note that GRUB assumes that your terminal emulator is
compatible with VT100 by default. This is true for most terminal
emulators nowadays, but you should pass the option `--dumb' to the
command, if your terminal emulator is not VT100-compatible or
implements few VT100 escape sequences. If you specify the option, then
GRUB doesn't provide you with the menu interface, because the menu
requires several fancy features for your terminal. Instead, GRUB only
gives you the hidden menu interface and the command-line interface"
Here is another interesting segment from the grub info file:
"GRUB's user interface
GRUB has both a simple menu interface for choosing preset entries
from a configuration file, and a highly flexible command-line for
performing any desired combination of boot commands.
GRUB looks for its configuration file as soon as it is loaded. If one
is found, then the full menu interface is activated using whatever
entries were found in the file. If you choose the "command-line" menu
option, or if the configuration file was not found, then GRUB drops to
the command-line interface."
"The simple menu interface
The menu interface is quite easy to use. Its commands are both
reasonably intuitive and described on screen.
Basically, the menu interface provides a list of "boot entries" to
the user to choose from. Use the arrow keys to select the entry of
choice, then press <RET> to run it. An optional timeout is available
to boot the default entry (the first one if not set), which is aborted
by pressing any key.
Commands are available to enter a bare command-line by pressing <c>
(which operates exactly like the non-config-file version of GRUB, but
allows one to return to the menu if desired by pressing <ESC>) or to
edit any of the "boot entries" by pressing <e>.
If you protect the menu interface with a password (*note Security::),
all you can do is choose an entry by pressing <RET>, or press <p> to
enter the password."
Grub has it's own tiny shell that you can use to do many things. One
possibility is to create grub floppy and play with it. That way you do
not mess with your current configuration.
>From grub FAQ:
How to create a GRUB boot floppy with the menu interface?
The easiest way is:
1. Create filesystem in your floppy disk. For example:
$ mke2fs /dev/fd0
2. Mount it on somewhere, say, `/mnt'.
3. Copy the GRUB images to `/mnt/boot/grub'. Only `stage1',
`stage2' and `grub.conf' are necessary. You may not copy
"stage1.5"s.
4. Run the following command (substitute `/usr/sbin/grub' for
`/sbin/grub' if you are using an older system):
$ /sbin/grub --batch <<EOT
root (fd0)
setup (fd0)
quit
EOT
end of FAQ segment.
Grub files traditionaly reside in /boot/grub.
I suggest you try command
pinfo grub
and learn more about grub that way. Command pinfo navigates similarly to
lynx, another words, it has links to other parts of document inside the
text.
Grub is usable even if the config file is messed up since you can edit
it at boot prompt. Not so for lilo. If config in lilo is bad you need
another way (floppy or CD) to boot and fix it.
I hope this helps you a bit to understand how grub works.
--
Rafael
On Mon, Aug 12, 2002 at 11:54:02AM -0400, Barbara J Wagreich wrote:
> Hi Listers:
>
> I sent the enclosed message over the weekend and received two responses
> that suggested I use grub instead of lilo to set up boots to
> multienvironments (windows 98, windows 2000, and Red Hat linux). It is my
> understanding that grub creates a menu. I am wondering if this menu is
> visible to brltty or whatever at boot time. The two respondents couldn't
> answer this question because they don't use adaptive devices.
>
> Does anyone on the list have experience with menus created by grub for
> multi OS environments with braille displays? Or is there another wayto
> set up multiboots that is accessible?
>
> Thanks for your help!
> Barb
>
>
> On Sat, 10 Aug 2002, Barbara J Wagreich wrote:
>
> > Hi All:
> >
> > I'm new to linux but have worked on UNIX.
> >
> > I'm sure you've discussed this topic before. I'd appreciate your
> > feedback.
> >
> > I am having a PC set up with three operating systems:
> > DOS/Windows 98, Windows 2000, and red Hat linux 7.2. I will be using
> > brltty
> > (I can't hear). A friend is doing this for me. (I would be using JFW
> > with Windows 98 and Windows 2K.)
> >
> > what is the best way to set up the multiboot sothat I can choose which OS
> > I want to invoke? Also, should the three partitions containing the 3
> > operating systems be hidden from each other?
> >
> > Thanks for your help!
> > Barbara Wagreich
> >