Why mx8mm android can't use memtool?

[ching-julo]

In that past, on imx6 android bsp, the memtool is workable and useful for engineer to adjust soc register.

While in imx8mm android bsp, memtool access register would cause system crash.

What's the difference?  How to enable memtool workable?

[gusarambula]

Hello Ching Ju Lo,

With each Android release security has become increasingly important. Given the symptoms when trying to read the registers it could be a problem with permissions. Have you tested with a userdebug (root access) Android build or enabling Development mode on your eng (development image)? (I would not recommend using a user image as it’s the most limited in terms of permissions and debugging)

I hope this helps!

Regards,

[ching-julo]

I'm using eng build, there is no sepolicy or permission problem.

Actually, when mmap function called,  system crash.

The problem should related to memory mapping.