[TriLUG] Stupid question time - Serial terminal and Linux

[Timothy A. Chagnon]

On Wed, 2004-02-25 at 11:09, Mike M wrote:
> On Tue, Feb 24, 2004 at 06:54:06PM -0500, Timothy A. Chagnon wrote:
> > Actually, I know it's possible with a little kernel futzing and lilo. 
> > Check out your /usr/src/linux-2.?/Documentation/serial-console.txt file
> > from the kernel source.
> > 
> > Specifically it says you can use the kernel boot line option
> > console=ttyS0,9600 to get /dev/console to the serial port.  That's just
> > kernel info though.
> 
> console= is a parm to lilo - yes?

Well console= is a parameter to the kernel.  That makes ttyS0 an output
for /dev/console messages once the kernel boots.  You need to compile
this support into the kernel though, as it's not in there by default.  I
don't think this supports input though, just kernel messages out.

The lilo option I don't know off hand, but I think it's supposed to give
you lilo menus and allow you to type at the boot: prompt over the serial
port.  At least for syslinux/pxelinux/isolinux you put SERIAL ttyS0 as
the first line in your ???linux.cfg file.

> The problem with x86 loading over serial is that you have to modify 
> so many things during the process.  LILO over serial one part.  You
> may also need have to have BIOS control to specify the boot media. Then
> syslinux or pxelinux needs to talk over COM1. Each and every time
> control is transferred to another program in the loading/booting/init
> process, modifications are necessary to talk over COMx instead of
> VGA/kbd.

Very true.  If you're installing though, you could probably do it with
just 1 place, your bootloader, whether it's
lilo/syslinux/isolinux/pxelinux/grub.  This would allow you to get a
boot: prompt where you can specify "linux ks" for kickstarting (I don't
know about FAI, looks like it's pxe+kickstart all together).
 
> This is for using a network for sourcing load files and automating the
> load process. Debian has the not-well-used FAI: 
> http://www.informatik.uni-koeln.de/fai/
> 
> This may be insufficient if the automated loading script is making the 
> wrong choices and the user needs to intervene in the loading process.

I don't know how FAI works, but for kickstart you can just make a
kickstart file about how you want the system set up with
system-config-kickstart (redhat-config-kickstart) and that will go
through the whole process with no user interaction.  The only thing you
need to do to make this work is specify "linux ks" on the boot: prompt
so it knows to get the kickstart file from an nfs source.  Just
specifying ks makes it go to the dhcp server (or next-server) and try to
get the file /kickstart/<IP>-kickstart through nfs where <IP> is the IP
of the machine getting installed.

Also, you would have to specify the installation media as nfs within the
kickstart file.

This would be a pretty blind install unless you give console=  to the
kernel.  At least then you would know a little about what's going on.

Who's doing this anyway? I've lost track of the thread originator.  It
would be helpful to know what distro they plan to use, what removable
media drives they have, and what type of NIC they have.

-Tim
-- 
Timothy A. Chagnon <tchagnon at nc.rr.com>