Transition to insecure mode fails

[andrewstevens-infineon]

The secure-mode start-up works fine but the call into nonsecure_init fails suggesting some part of the setup of the non-secure execution context is buggy...

Address: 0x2007c1
|mpu_region: 0
|sau_region: 0
|mpu_region_valid: 0
|sau_region_valid: 1
|read_ok: 1
|readwrite_ok: 1
|nonsecure_read_ok: 1
|nonsecure_readwrite_ok: 1
|secure: 0
|idau_region_valid: 1
|idau_region: 0

Taking exception 3 [Prefetch Abort]
...really SecureFault with SFSR.INVEP
...taking pending secure exception 3

[imcchaves]

Actually what fails is the SG instruction when NS tries to call S side. So probably something with SAU/IDAU configuration.

(gdb) x/4i 0x100019e0
0x100019e0 <sec_sum>: sg
0x100019e4 <sec_sum+4>: b.w 0x10000a00 <sec_sum>
0x100019e8: movs r0, r0
0x100019ea: movs r0, r0

And from the ARM documentation:
SFSR.INVEP:
Invalid entry point. This bit is set if a function call from the Non-secure state or exception targets a non-SG instruction in the Secure state. This bit is also set if the target address is an SG instruction, but there is no matching SAU/IDAU region with the NSC flag set.

[imcchaves]

The problem is that the SAU region 2 has wrong addresses. It nees to be adjusted to the veneers function.
After this change the code works properly.