RE: Start another PXE loader from grub?

[#IS Department]

Just a follow-up on what I’ve found.  Grub (at least v1.98 that I’m using) doesn’t have the ability to load another pxe boot image.  But, gpxe can be built in just about any form you need it to be from http://rom-o-matic.net/.  In the thread I linked to (here’s a better link, apparently the archiveorange version isn’t complete, even though it is more readable: http://syslinux.zytor.com/archives/2010-March/013814.html) they were using pxelinux to chain a gpxe kkpxe loader.  You can use a linux kernel loadable image of gpxe to replicate the results using grub.

 

Rob

 

 

From: address@hidden [mailto:address@hidden On Behalf Of #IS Department
Sent: Wednesday, December 01, 2010 1:45 PM
To: address@hidden
Subject: Start another PXE loader from grub?

 

Recently I have implemented a PXE boot environment and I am hoping to use grub as my boot manager.  I downloaded the grub 1.98 source and built it.  I then built a PXE boot file, grub.pxe, following the instructions in the manual.

 

I have a tested WinPE PXE boot image that works as expected if I specify pxeboot.n12 in dhcp option 67, Boot File Name.  So, now I am in the process of replacing pxeboot.n12 with grub.pxe.  If I try to load pxeboot.n12 from grub with either the linux or linux16 commands I get “error: invalid magic number.”  If I try with the chainloader command I get “error: invalid signature”, and if I try it with the --force option it reboots the machine.

 

Is there a way to boot another PXE loader from grub?

 

On a related note, is there a way to edit dhcp options in the pxe stack from the grub command line?  Basically I hope to be able to do something similar to this: http://web.archiveorange.com/archive/v/mwjwmKpW8U1WLTg22Vaq  When WinPE starts it looks for a WDS server to give it a BCD bootloader.  If the server doesn’t respond then it will attempt to download the file from the tftp server.  If you can edit dhcp option 252 from the grub command line, then it becomes possible to boot multiple windows boot images by specifying the BCD file in the dhcp option.  This can also be accomplished by adding multiple entries to the BCD file on the tftp server, but it would be nice if you could manage all the boot options from the grub menu.  It would also streamline the WinPE boot process as there would be no timeout waiting for a response from a nonexistent WDS server.

 

I believe this should all be possible using PXELinux, but I’m more familiar with grub and would prefer to use it if possible.

 

Any help is appreciated.

 

Rob