Showing results for 
Search instead for 
Did you mean: 

Bus Fault when PUSH instruction is execute when calling nonsecure entry function


I am currently working on a project using STM32U575 with Trust Zone activated.

I am using IAR compiler.

I am facing an issue where Bus Fault is triggered whenever a PUSH isntruction is executed during the call to a cmse_nonsecure_entry function

0693W00000aIzi4QAC.png0693W00000aIziJQAS.png0693W00000aIzidQAC.pngBFAR address value is always this random 0xffff xxxx value (e.g. 0xffff'fff8 or 0xffff'fffe)

The PUSH instruction is always in the disassembly whenever the entry function calls another function which also exist in the Secure region. If no call to a Secure region function is done and only basic operations are there, the entry function works fine and no bus fault occurs.

What seems to be the problem here?

Billy OWEN
ST Employee

Hi @RCana.2​ 

The forum moderator had marked your post as needing a little more investigation and direct support. An online support case has been created on your behalf, please stand by for just a moment and you will hear from us.