Using the Signature Unit

[lars_r_andersso]

As described in section 15.9.2.3.6.16 of the 8QuadXPlus Applications Processor Reference Manual, the Display Controller has a "Signature Unit" that makes it possible to automatically test the checksum of several user-defined regions in the frame buffer.

Does the imx8qxpmek Linux BSP image include any drivers/libraries for accessing this functionality from user space? 

[igorpadykov · Accepted solution]

Hi Lars

example can be found in SDK_MEK-MIMX8QX on Welcome | MCUXpresso SDK Builder 

..driver_examples/dpu/signature/dpu_signature.c

Linux has not signature examples/libraries.

Best regards
igor
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[lars_r_andersso]

Thanks Igor, that is useful.

So the signature checking code needs to run on the M4? Or can it be used from the A-cores to?

Do you know of any utility that can be used to reprogram and restart the M4 on a 8QuadXPlus from Linux? Something similar to what is being described here, but for the 8QuadXPlus:

https://www.nxp.com/docs/en/application-note/AN5317.pdf 

[igorpadykov]

Hi Lars

yes it can be used from the A-cores too.

Tool for loading M4 from linux

m4ctrl - M4 Control Tool for i.MX platforms 

Best regards
igor

[lars_r_andersso]

I've cross compiled m4ctrl and m4ctrl_dev.ko.

After inserting the kernel module, I'm trying to deploy the hello_world_TCM.bin binary on the M4 using:

root@imx8qxpmek:~# ./m4ctrl --deploy hello_world_TCM.bin
Stop cortex M4, core 0
ioctl: Input/output error

dmesg:

[ 243.730740] stoping the core M0
[ 243.730862] pwroff the core M0

On the serial console (attached to the M4), I see this:

#################### CODEC SRTM DEMO ####################

Build Time: Mar 25 2019--15:31:14

##########################################################
Press 'r' to do M4 partition reset

Is this printed by code running on the M4?

Any idea why I'm getting ioctl: Input/output error when trying to run m4ctrl --deploy?

[igorpadykov]

for new questions may be suggested to create new thread.

Best regards
igor

[lars_r_andersso]

Ok, I will start a new thread about the m4ctrl issue.

[lars_r_andersso]

Thanks, m4ctrl looks very useful.