Embedding a variable upon compile

Embedding a variable upon compile - Printable Version

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Embedding a variable upon compile - nappington - 2015-07-29 16:07

I'm just curious if it's possible to embed a variable when compiling undionly.kpxe

We have a situation where we need multiple serial baud rates - we have the ability specify which version of undionly.kpxe to use for that specific baud rate/machine that netboots, but we need a way to pass through the baud rate to the next installer.

Currently we have the ability to alter the version setting (http://ipxe.org/cfg/version) during compile, but we'd rather not use that method. I'm curious if there are any other settings/variables that we can alter the contents of.

Thanks!

RE: Embedding a variable upon compile - NiKiZe - 2015-07-29 18:25

(2015-07-29 16:07)nappington Wrote: I'm just curious if it's possible to embed a variable when compiling undionly.kpxe

We have a situation where we need multiple serial baud rates - we have the ability specify which version of undionly.kpxe to use for that specific baud rate/machine that netboots, but we need a way to pass through the baud rate to the next installer.

You could use an embedded script such as

Code:

#!ipxe

prompt --key 0x02 --timeout 2000 Press Ctrl-B for the iPXE command line... && shell ||

set serialspeed 19200

autoboot

it will set serialspeed variable and continue to boot.
or you can have this in the script based on mac or other options.

RE: Embedding a variable upon compile - nappington - 2015-07-30 02:29

True that - however, that does require me to have a completely separate script for each serial speed variable and keep each of them up to date if I want to make any changes.

I would like to use a single embedded script so I'm wondering if there's any way to set it hardcoded into the binary itself, similar to how I can make changes to the 'version' setting on compilation.

RE: Embedding a variable upon compile - NiKiZe - 2015-08-01 08:00

You can create an setting that returns a separate value that you set on compile time.
But I don't see how that is easier than creating a build script..

Code:

#!/bin/bash

echo #!ipxe > embed.ipxe

echo set serialspeed $1 >> embed.ipxe

cat commonscript.ipxe >> embed.ipxe

make $2 EMBED=embed.ipxe

This will combine a variable and the base script when this buildscript is run.
So you will only have one script and the rest is still automatic.

adding an embeded script - is the same as setting it in the binary itself - just much easier then any alternative.

RE: Embedding a variable upon compile - nappington - 2015-08-02 20:05

Thanks for the answer - I wonder if there's an easier way to do it and if there's a way simply pull the baud rate directly from an iPXE shell? e.g. it's already in a variable somewhere that I can echo.