Netboot 10.9 on older Mac’s

Keep getting no-entry signs booting from a net boot image made on a mac that boots fine from the same image when its on a HDD ? New Macs Netboot fine but old ones don’t ? Check the kernalcache in the .nbi folder.

TFTP original file limits is 32MB. I think new models have removed this limit in there firmware. All my old NB images kernalcache files are under that size.

10.9.x ones are 35MB so won’t TFTP to the older macs. If I remove unused kexts and build the image the kernalcache is under 32MB and EVERYTHING boots !!!!

I think Apple needs to look at system image utility and make it more selective on needed kexts

UPDATE:  I have written 2 scripts that will rebuild the kernelcache for you. is a simple cache rebuilder where will do everything for you including growing the DMG