✎ soc:2009:pravin:journal:pxekniferomomatic

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====== Pxeknife integretion with rom-o-matic ======


===== Plan =====

provide pxe images/rom/nic with gpxe script embedded.  This script will connect to pxeknife server to get boot loader.

===== Implementation =====

In file rom-o-matic/build.php the image is compiled by following command
<code>
make -C '$dir' '$target'
</code>

I have modified it to compile with embedded image by modifying above code with
<code>
make -C '$dir' EMBEDDED_IMAGE=./pxeDHCP.gpxe '$target'
</code>

the script //./pxeDHCP.gpxe// contains following code
<code>
#!gpxe
echo "Hi, We will be using PXEKnife from URL http://www.alien.doesntexist.org/pxeknife"
echo "It is assumed that you have dhcp networking"
imgload pxeSTATIC.gpxe
imgstat
ifopen net0
echo "Hit Control+C to cancel DHCP"
echo "You may want to do this if you want to use static-IP"
echo "Otherwise, it will try DHCP, and then anyway go to static-IP"
sleep 4
dhcp net0
set 209:string pxelinux.cfg/default
set 210:string http://www.alien.doesntexist.org/pxeknife/
echo "Here we go"
chain http://www.alien.doesntexist.org/pxeknife/pxelinux.0
echo "PxeKnife booting cancelled, using local disk instead.."
</code>
The code is hosted at url [[http://www.alien.doesntexist.org/pxeknife/PHP/gpxe_generation/]]



===== Problems =====

When I boot using qemu with following command
<code>
qemu -fda gpxe-git-e1000.dsk
</code>
I get following error

<code>
no such interface: net0
</code>
and booting fails :-(. I also tried with gpxe-git-3c509-eisa.dsk but same result.\\

But when I compile the the gpxe with same script and no target, it works fine


<code>
make EMBEDDED_IMAGE=./pxeDHCP.gpxe
qemu -fda bin/gpxe.dsk
</code>

==== Solution ====
Problem was that, qemu does not support all network drivers, and you need to tell qemu which device driver to emulate.
Following qemu command is working for rtl8139

===== For static IP =====
To support static IP, the plan is to have two scripts, one with DHCP and one with Static.
When DHCP fails, static will pick up and continue execution.

==== Problem ====
Second script is not getting executed.
I had to load the second script from first script using imgload
<code>
imgload pxeSTATIC.gpxe
</code>
Other than that,
I had to comment out the break statement in //core/main.c// inside function //main()// 
there is a loop which iterate over each image. but there was a break, which had to be removed.
<code>
        if ( have_images() ) {
            for_each_image ( image ) {
                image_exec ( image );
                /* break;  */ /* commented so that second script will be executed -- pravin */
            }
        } else {

</code>

Other change is done in //image/script.c// file inside function //script_exec()// where at end, it re-registers the script.
The second executable does not get executed when this line is there, so, I commented it out.
I am not sure what exactly is the problem, but my guess is that, \\
re_register puts the script on top of the list, but older mapping where second script  was loaded in memory gets messed up somehow.

<code>
	rc = 0;
 done:
	/* Re-register image and return */
	register_image ( image );    /* commented so that next one will be executed -- pravin */
	return rc;
}

</code>

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