Use this option if you want to load bootloader driver.
This value should be specified when the bootloader driver is disabled and must be exactly two characters long. Families supported are: R1 - RNG-100 R2 - RNG-200 A1 - Class A B1 - Class B E1 - Class E F1 - Class F 44 - 45xx 46 - 46xx 85 - 85xx 86 - 86xx