[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Qemu and ARM secure state.

From: Jean-Christophe DUBOIS
Subject: Qemu and ARM secure state.
Date: Wed, 3 Nov 2021 14:27:17 +0100
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.1.2


I have a little application that is designed to work on the i.MX6UL processor.

I developed it and tested it on the mcimx6ul-evk platform emulated by Qemu.

This application used to work "flawlessly" on Qemu 5.0.50 and is working on Qemu 6.0.0 (available as a pre-built package on the latest Ubuntu).

But when I try to run the exact same command line on a Qemu version I compile myself from main/latest of github (Qemu 6.1.50), my application fails to start.

So a little background:

My application expects to start in "secure" state and supervisor mode (which is the default state of i.MX6UL when booting barebone [without u-boot]).

From this state the application tries to get to "non secure" / hypervisor mode which imply going to the "secure" / monitor state before being able to drop to "non secure" / hypervisor. To do so is runs a "smc 0" operand (from "secure" / supervisor).

This "smc" instruction is processed "as expected" by Qemu 5.0.50 and Qemu 6.0.0 (getting to "secure" / monitor mode) but on Qemu 6.1.50 (latest from github) it is as if the smc operand was a no-op. It doesn't trigger any exception and the processor just get to the next instruction after the "smc" instruction. So I am a bit puzzled.

Thanks for your help.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]