Windows 8 on USB disk - plop can boot disk, BIOS USB not ?

[darko]

I have installed Windows 8 CP on an external disk connected via USB 2.
(Installation method - install.wim + imagex and following bcdboot command)

I can boot Windows 8 installed on USB disk via plop boot manager.

I cannot boot Windows 8 installed on USB disk via BIOS USB entry (disk is recognized correctly in BIOS).

Is plop using some special USB low level operations not implemented in BIOS ?

[Elmar]

Is plop using some special USB low level operations not implemented in BIOS ?

no, nothing special

regards
elmar