I am using Kinetis Design Studio, with KSDK_1.3.0, debugger - Segger Base. Project uses only basic HAL - i.e. register references only, no Processor Expert and no other drivers. Finally, when firmware was ready, I wanted to secure it, but get
in a trouble.
Ending was default: FE - 0xFE (Backdoor key access disabled, Mass erase is enabled, NXP factory access granted, MCU security status is unsecure). So just want to set SEC b00 - MCU security status is secure.
So got this:
I loocked over here and found about two similar posts, and answer seems to be clear.
We are developing code for about a year, and through all this time I used to upload firmware through debug mode,
so simply catched my own tail: I wanted to lock MCU and start debug.
So I opened Flash from File and ....confused, this is the same as debug template, and certainly, result is the same.
I tried different combinations of FSLACC-SEC then: in some combination(don't remember exact) alert disappeared.
Then I added some code to check FTFA_FSEC register, just print it to PC terminal over RS-232 (wires connection available on our device housing), certainly, no security state again. FTFA_FSEC [1:0] is always b10.
I am new at Kinetis MCU-s, so really sorry... please explain me step by step how to upload secure firmware.