Re: Debian-installer export custom variable

[Brian Potkin <claremont102@gmail.com>]

On Sat 22 Dec 2012 at 11:17:00 +0000, Philip Hands wrote:

> Brian Potkin <claremont102@gmail.com> writes:
> >
> >     To illustrate this, here are some examples that can be used
> >      at the boot prompt: . . . .
> > All three examples which follow begin with "auto". So I typed
> >
> >    auto url=file:///mnt/./preseed.cfg
> 
> It's not clear from your reply if you added that to the existing command
> line, or that was the complete command line.

At menu item Install I pressed TAB and added the line to the end of the
existing one. Thanks to your explanation I now realise this is entirely
the wrong thing to do on Wheezy..

The important term is "boot prompt". Under Etch we saw

   Press F1 for help, or ENTER to boot:

at the splash screen. The advice given in the Guide was:

     At the boot prompt you can either just press Enter to boot
     the installer with default options or enter a specific boot
     method and, optionally, boot parameters.

A "boot method" (such as install, expert or auto) is what you refer to
as a "target". I think both terms refer to what syslinux has as "label".

Under Wheezy the splash screen menu allows editing of the kernel command
line. As far as I can see, one can get a boot prompt in a number of
ways. For example: via the Help menu item. pressing ESC at the boot menu
or holding down the ALT key while the installer is booting.
 
> The confusion here is arising from the fact that we're using "auto" in
> two difference contexts.  If it's the first thing on the command line
> then it's used as the name to look up which kernel to boot in the
> syslinux config, and where defined that will include the relevant
> options, whereas if not defined it will simply throw an error and do
> nothing.

The present Section B.2.3. does distinguish between what to have at a
boot prompt and what to put on the kernel command line, but a useful
documentation change might be to replace

     To illustrate this, here are some examples that can be used
     at the boot prompt:

with (for example)

     To illustrate this, here are some examples that can be used 
     at the boot prompt, which can be accessed from the Help
     option in the boot menu:

Regards,

Brian.