First you have to download an iso cdrom image of squeeze: -Extract it's initrd.gz -ungzip it -make directory, enter it and use cpio -id < ../initrd to have files a -get files from /lib/modules/KERNEL_VERSION/kernel/drivers/scsi/
Second download NetBoot image (same release that cdrom image) Extract it's initrd.gz, ungzip it and put files into the same path that cdrom iso. It must have the same KERNEL_VERSION.