How read NRF_FICR in non-secure core? NRF5340

[Roberto Cortez]

Hi all, I try read DEVICEID in non-secure application but always return "BUS FAULT", I tried too enable NRF_FICR register in "spm.c" but the error persist!

I try

NRF_FICR_S->INFO.DEVICEID[0]

 and

NRF_FICR->INFO.DEVICEID[0]

00> [00:00:00.404,602] <err> os: ***** BUS FAULT *****
00> [00:00:00.404,602] <err> os:   Precise data bus error
00> [00:00:00.404,632] <err> os:   BFAR Address: 0xff0204
00> [00:00:00.404,632] <err> os: r0/a1:  0x0003797b  r1/a2:  0x20022848  r2/a3:  0x200111f8
00> [00:00:00.404,632] <err> os: r3/a4:  0x00ff0000 r12/ip:  0x00000001 r14/lr:  0x0000dd33
00> [00:00:00.404,632] <err> os:  xpsr:  0x81000000
00> [00:00:00.404,632] <err> os: Faulting instruction address (r15/pc): 0x0000cbde
00> [00:00:00.404,663] <err> os: >>> ZEPHYR FATAL ERROR 0: CPU exception on CPU 0
00> [00:00:00.404,693] <err> os: Current thread: 0x20012858 (main)
00> [00:00:01.623,016] <err> os: Halting system

Regards.

[Carl Richard]

Hello, Roberto!

Quoting the documentation: "The user information configuration registers (UICR) and factory information configuration registers (FICR) are always considered as secure."
However, it is possible to get the device ID by using secure entry functions. You can check out this guide. I've also attached a project demonstrating how the FICR can be read using this method.

The bus fault probably relates to errata 51 of the nRF5340.

Secure entry function demo for NCS v1.3.0:
4380.spm_demo.zip

Best regards,
Carl Richard