HP/ASUS PTGV-LM/PTGV-DM Motherboard mini itx need automatic boot from usb

[hank]

HI, my first post here .. as subjet i have this mobo mini ITX from my HP mini pc palvillion s7400n
i'm planning to use it as a freenas server due to its low power consumption but i want to install freenas on a usb pen to save the sata port for data hdd.

my current bios rev is the last available on HPwebsite : 3.06

i currently boot from usb only if i press ESC on startup during post
inside bios option is not posssible to select usb for boot, only fdd cdrom hdd and network

could be possible to enable to boot from usb without pressing esc by enblling
a specific op tion inside bios..??
for example instead of FDD (fdd connection is also not present on my mobo so this option is not useful)

here is the self executing with bios update from Hp website
ftp://ftp.hp.com/pub/softlib/software6/C...p26641.exe

thank you so much