S32K144 CSEc Strict Sequential Boot Mode

[soulyoung]

Hello, I have encountered a problem. I enabled the Strict Sequential Boot Mode in Secure Boot on the s32k144 chip. I wanted to see what state the MCU would be in if I modified the boot. As a result, I found that the chip was always in reset state. The reset pin was always low, which made it impossible for me to re-burn the correct boot to release the reset state caused by the CSEc verification failure. I did not enable debug disable and did not disable mess erase. Is there any way to recover?

[lukaszadrapa · Accepted solution]

Hi @soulyoung 

There's no way to recover. If strict sequential boot mode fails, the device will stay in reset forever. The only option is to replace the chip. The documentation warns about that several times:

lukaszadrapa_0-1745838466688.png

lukaszadrapa_1-1745838517416.png

 The last sentence "may execute ROM code" comes from SHE specification but that's not the case here.

lukaszadrapa_2-1745838634382.png

Regards,

Lukas