Document: AN12079.pdf: How to use i.MXRT Security Boot, Application Notes, Rev. 0, 10/2017
Section: 3.3.2. Generate SB file for FlexSPI NOR image encryption and programming
The example .bd file contains the lines:
#6. Program BEE_KEY0_SEL and BEE_KEY1_SEL
load fuse 0x0000e000 > 0x06;
BEE_KEY0_SEL to 10 = Reserved
BEE_KEY1_SEL to 11 = From SW-GP2
Why is BEE_KEY0_SEL being set to a reserved value?
Presumably only bit 1 of these two fields (i.e. bits 0x460 and 0x460) are actually observed by the ROM bootloader?