On Fri, Jan 15, 2021 at 12:50:27PM +0000, Jens Wiklander via OP-TEE wrote:

Hi Kris,

On Thu, Jan 14, 2021 at 1:37 PM Kris Kwiatkowski kris@amongbytes.com wrote:

...

Hi,

I'm using HiKey 960 for my research project. I've noticed that filesystem is not persistent between reboot. Is there a way to change it, so that any change to file in the /etc will be persistent?

There's no easy way of doing that with our repo based builds I'm aware of. The purpose of our (OP-TEE team) builds is in principle to be able to execute xtest and other test programs. For this use case it's actually an advantage to start from a clean state each time. In your case I think you need to pick a suitable distribution and update it as needed to support OP-TEE. It could be worth looking at Yocto as there is some OP-TEE support already.

You can also give NFS a try, I tend to use that myself when playing with OP-TEE and Raspberry Pi3. I.e., I basically just untar the rootfs created by our setup into a folder that is exposed via NFS. Then in addition to that I have a couple of helper scripts that copies the files Jens mentioned below into that NFS folder when I need to update with changed files (TA's, OP-TEE libs etc).

Here's a short list of what's needed:

1. TF-A compiled with OP-TEE support (dispatcher in BL31 and load

support in bl2) 2. OP-TEE included in the FIP loaded by TF-A 3. OP-TEE nodes in device tree 4. OP-TEE driver enabled in the kernel (recent upstream kernel should work in most cases) 5. tee-supplicant and libteec.so installed in the file system 6. tee-supplicant started

With that in place you should be good to go.

Cheers, Jens