OPTEE on Rpi3 hardware
FOR STUDENTS WHO WANT TO EXPERIMENT REAL HARDWARE.
If you are unsure, use QEMU. See here
Read the instructions for QEMU here. will follow a similar procedure with minor tweaks.
Grab source. Note that we point to rpi3.xml instead of qemu_v8.xml:
$ mkdir -p ~/bin
$ curl https://storage.googleapis.com/git-repo-downloads/repo > ~/bin/repo && chmod a+x ~/bin/repo
$ export PATH=~/bin:$PATH
$ mkdir optee-rpi3 && cd optee-rpi3 && \
repo init -q -u https://github.com/OP-TEE/manifest.git -m rpi3.xml -b 3.9.0 && \
repo sync -j4 --no-clone-bundle
Build:
$ cd build
$ make -j2 toolchains
$ make -j`nproc` # note we don't need flags for VIRTFS, etc.
The build output will be out-br/images/rootfs which is the filesystem tree (and image) for Rpi3.
Prepare the SD card:
In the following steps, we will load the filesystem tree to a microSD card. OPTEE's instructions for Rpi3 suggest you to go build/ and run make img-help to see the list of commands. Here is a sample output from my computer; you should follow the commands displayed when you rum make img-help on your computer.
These commands are nothing magical:
i) format a microSD card from scratch. The commands use fdisk to create two partitions: boot (32MB, FAT32) and rootfs (spanning the rest of the microSD card, ext4).
ii) load the filesystem image to the card. The commands extract boot/ and / from the filesystem image (*.cpio) to the two partitions of the microSD card, respectively.
Note: these commands assume that you have a local Linux machine, to which you can plug in the micro SD card (via a card reader) and partition it. What if you only have a Windows or Mac machine? I think you can use WSL/Win32DiskImager for the former and diskutil on the latter. Some ref here. I haven't tried either. You can tell me your findings.
Boot Rpi3 from the micro SD card:
Power on Rpi3 and hook up a serial cable. We boot into a Linux console (root, empty password) from a serial console:
Then we can validate that OPTEE works by running the xtest suite. Hooray! :grin:
Note: Both the normal and the secure worlds share the same console. Secure world has higher privilege and its output will overwrite that of the normal world.
