Boot looping and Chainloading

NOTICE: FOG no longer uses syslinux. The below content is left intact because it may help someone with something, but it's not been updated since 2013 and no longer relevant to the FOG Project.

Overview

Some computer models may experience problems booting to the next device after performing a PXE boot and loading the Fog boot menu. This problem has been mostly observed with Dell computers but can happen on others as well.

The steps below will help you modify your Fog installation to support Chainloading to bypass the BIOS boot device order, and proceed to the first hard drive after the Fog menu exits.

From this forum thread: http://fogproject.org/forum/threads/after-deploying-image-reboot-loop-dell-e6520-fog-0-32.445/

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Apparently there were several versions of PXELINUX that had issues with chainloading, and the current version of FOG uses one of those. Here is a copy of the steps used to setup chainloading:

Update SYSLINUX

• Download and extract the latest SYSLINUX (Currently using 4.04): http://www.kernel.org/pub/linux/utils/boot/syslinux/
• Copy/Overwrite the following files to /tftpboot/:

   syslinux-4.04/com32/modules/chain.c32
   syslinux-4.04/com32/menu/vesamenu.c32
   syslinux-4.04/core/pxelinux.0
 

Update the Fog boot menu

Text based menu

Only set this if you're using the text based menu

• Edit /tftpboot/pxelinux.cfg/default to include the following DEFAULT option and LABEL entry:

  DEFAULT fog.next 
  LABEL fog.next 
      kernel chain.c32 
      append hd0

Graphical menu

• If you are using the Graphical menu modify fog.local in your /tftpboot/pxelinux.cfg/default to look like this

    LABEL fog.local
           kernel chain.c32
           append hd0
           MENU DEFAULT
           MENU LABEL Boot from hard disk
           TEXT HELP
                 Boot from the local hard drive.
                 If you are unsure, select this option.
           ENDTEXT

Warnings

WARNING: Using this configuration does have some side effects:

Chainloading bypasses the BIOS boot device list and will go straight from the FOG boot menu loaded during network boot to the MBR of the first hard drive recognized by the motherboard. This means that you cannot boot to a bootable CD or flash drive after network booting, the same goes for any bootable hard drives other than the first one recognized by the motherboard; to access other bootable devices you must select the boot menu option during POST and manually select the bootable device desired.