In current tf-m, how could I disable bl2 and execute tf-m secure part when reset directly?
There is an md file in the trusted-firmware-m repo documenting the secure boot process:
Paragraph starting at line 111:
Compile time switches
describes the switch you need to toggle in the build config file you intend to use (ConfigDefault.cmake, ConfigRegression.cmake, ...)
tfm_user_guide.md describes the differences in execution of the resulting binaries when running with/without BL2.
I see, thanks a lot.