I was helping my son recover a Toshiba 17" laptop (a P275 something). It's got an i7 processor so it seems like it's fairly recent.
Anyway, I was trying to boot BING (tried both USB stick and USB DVD drive) from USB, and I couldn't get it to even see the drive, even after disabling Secure Boot and changing from UEFI to CSM.
I found this:
and the post on Sept. 29, 2015 by "Barth_bs" he says:
"you must be make an UEFI Boot USB Stick"
"and change partition scheme and target system type to :
GPT partition scheme only for UEFI
and toshiba can only detect USB Boot with UEFi format...
try it.... don't forget to backup your data before.
If I'm reading that correctly, he is saying that even with CSM and Secure Boot disabled, this laptop won't recognize a USB boot device and it only recognizes boot media that is UEFI?
Does anyone know if that is really the case? Do they actually disable booting from USB unless it is UEFI?
Just curious, in case I run across this again some time down the road