Board specific mcuboot keys

[Anthony Ambuehl]

NCS 2.7

Sysbuild with mcuboot

3 board variants defined by common board with 3 revisions: [email protected],  [email protected], [email protected]

2 applications: manufacturing and customer (mfg_app and app)

I would like to setup custom image signing keys that are specific to board variants.  This will avoid accidentally loading an image on the wrong board variant.  

Also since I have multiple applications to build, I think it would make sense for the keys to be in a common directory outside of the application.

I found this discussion that recommend using APP_DIR to locate the files, but is there another variable that gets the fully qualified board name?

[AHaug]

Hi,

Using APP_DIR is recommended per that discussion, but if you have your keys in a directory outside of the application you should be able to specify so by adding ../APP_DIR to the relative path

Kind regards,
Andreas

[Anthony Ambuehl]

Yes the relative path works with APP_DIR.   I also found that ${BOARD} works to select the board name, but I also need to select with the revision number as well. 

Is there a ${REVISION} or ${QUALIFIER}  or ${BOARD_REVISION}?

Is there someplace I can find what variables will be expanded in sysbuild.conf?

I want to pick some like  

${APP_DIR}/../../keys/${$BOARD}_${REVISION}_private_key.pm

such as app/../../keys/plank_1_0_1_private_key.pm