whichsys.c32 is a COM32 module for Syslinux that determines which command to execute, based on the Syslinux bootloader variant from which it is run.
It is only available in Syslinux 4.02 or later.
Usage: whichsys.c32 [-iso- command] [-pxe- command] [-sys- command]
Boot the first hard disk when booted from ISOLINUX, boot the second hard disk (internal hard disk when your USB drive is detected as hard disk 1 by the BIOS) and swap drive numbers when booted from SYSLINUX:
whichsys.c32 -iso- chain.c32 hd0 -sys- chain.c32 hd1 swap
Load a specifc config file for each bootloader:
whichsys.c32 -iso- config iso.cfg -sys- config sys.cfg -pxe- config pxe.cfg