modified BIOS must be flashed using the SPI flash programmer (as here https://forums.mydigitallife.net/threads/award-ami-bios-mod-requests.5863/page-3116#post-1475389 ). in the latest BIOS from Asrock the BIOS digital signature verification is strengthened
fixed, https://forums.mydigitallife.net/threads/award-ami-bios-mod-requests.5863/page-2749#post-973317