OP-TEE Trusted OS

Contents

1. Introduction
2. License
3. Platforms supported
   1. [Development board for community user] (#31-development-board-for-community-user)
4. Get and build OP-TEE software
   1. Prerequisites
   2. Basic setup
   3. STMicroelectronics boards
   4. Allwinner A80
   5. Freescale MX6UL EVK
5. repo manifests
   1. Install repo
   2. Get the source code
      1. Targets
      2. Branches
      3. Get the toolchains
   3. QEMU
   4. FVP
   5. HiKey
   6. MT8173-EVB
   7. Juno
      1. Update flash and its layout
   8. Tips and tricks
      1. Reference existing project to speed up repo sync
      2. Use ccache
6. Load driver, tee-supplicant and run xtest
7. Coding standards
   1. checkpatch

1. Introduction

The optee_os git, contains the source code for the TEE in Linux using the ARM® TrustZone® technology. This component meets the GlobalPlatform TEE System Architecture specification. It also provides the TEE Internal core API v1.1 as defined by the GlobalPlatform TEE Standard for the development of Trusted Applications. For a general overview of OP-TEE and to find out how to contribute, please see the Notice.md file.

The Trusted OS is accessible from the Rich OS (Linux) using the GlobalPlatform TEE Client API Specification v1.0, which also is used to trigger secure execution of applications within the TEE.

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2. License

The software is distributed mostly under the BSD 2-Clause open source license, apart from some files in the optee_os/lib/libutils directory which are distributed under the BSD 3-Clause or public domain licenses.

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3. Platforms supported

Several platforms are supported. In order to manage slight differences between platforms, a PLATFORM_FLAVOR flag has been introduced. The PLATFORM and PLATFORM_FLAVOR flags define the whole configuration for a chip the where the Trusted OS runs. Note that there is also a composite form which makes it possible to append PLATFORM_FLAVOR directly, by adding a dash in-between the names. The composite form is shown below for the different boards. For more specific details about build flags etc, please read the file build_system.md. Some platforms have different sub-maintainers, please refer to the file MAINTAINERS.md for contact details for various platforms.

Platform	Composite PLATFORM flag	Publicly available?
Allwinner A80 Board	PLATFORM=sunxi	No
ARM Juno Board	PLATFORM=vexpress-juno	Yes
FSL ls1021a	PLATFORM=ls-ls1021atwr	Yes
FSL i.MX6 UltraLite EVK Board	PLATFORM=imx	Yes
ARM Foundation FVP	PLATFORM=vexpress-fvp	Yes
HiKey Board (HiSilicon Kirin 620)	PLATFORM=hikey	Yes
MediaTek MT8173 EVB Board	PLATFORM=mediatek-mt8173	No
QEMU	PLATFORM=vexpress-qemu_virt	Yes
STMicroelectronics b2120 - h310 / h410	PLATFORM=stm-cannes	No
STMicroelectronics b2020-h416	PLATFORM=stm-orly2	No
Texas Instruments DRA7xx	PLATFORM=ti-dra7xx	Yes

3.1 Development board for community user

For community users, we suggest using HiKey board as development board. It provides detailed documentation including chip datasheet, board schematics, source code, binaries etc on the download link at the website.

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4. Get and build OP-TEE software

There are a couple of different build options depending on the target you are going to use. If you just want to get the software and compile it, then you should follow the instructions under the "Basic setup" below. In case you are going to run for a certain hardware or FVP, QEMU for example, then please follow the respective section found below instead, having that said, we are moving from the shell script based setups to instead use repo, so for some targets you will see that we are using repo (section 5) and for others we are still using the shell script based setup (section 4), please see this transitions as work in progress.

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4.1 Prerequisites

We believe that you can use any Linux distribution to build OP-TEE, but as maintainers of OP-TEE we are mainly using Ubuntu-based distributions and to be able to build and run OP-TEE there are a few packages that needs to be installed to start with. Therefore install the following packages regardless of what target you will use in the end.

$ sudo apt-get install android-tools-fastboot autoconf bison cscope curl \
               flex gdisk libc6:i386 libfdt-dev libglib2.0-dev \
               libpixman-1-dev libstdc++6:i386 libz1:i386 netcat \
               python-crypto python-serial uuid-dev xz-utils zlib1g-dev

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4.2 Basic setup

4.2.1 Get the compiler

We strive to use the latest available compiler from Linaro. Start by downloading and unpacking the compiler. Then export the PATH to the compilers bin folder. Beware that we are using a couple of different toolchains depending on the target device. This includes both 64- and 32-bit toolchains. For the exact toolchain in use, please have a look at toolchain.mk and then look at the targets makefile (see build.git) to find out where the respective toolchain will be used. For example in the QEMU makefile you will see:

CROSS_COMPILE_NS_USER        ?= "$(CCACHE)$(AARCH32_CROSS_COMPILE)"
CROSS_COMPILE_NS_KERNEL        ?= "$(CCACHE)$(AARCH32_CROSS_COMPILE)"
CROSS_COMPILE_S_USER        ?= "$(CCACHE)$(AARCH32_CROSS_COMPILE)"
CROSS_COMPILE_S_KERNEL        ?= "$(CCACHE)$(AARCH32_CROSS_COMPILE)"

However, if you only want to compile optee_os, then you can do like this:

$ cd $HOME
$ mkdir toolchains
$ cd toolchains
$ wget http://releases.linaro.org/14.08/components/toolchain/binaries/gcc-linaro-arm-linux-gnueabihf-4.9-2014.08_linux.tar.xz
$ tar xvf gcc-linaro-arm-linux-gnueabihf-4.9-2014.08_linux.tar.xz
$ export PATH=$HOME/toolchains/gcc-linaro-arm-linux-gnueabihf-4.9-2014.08_linux/bin:$PATH

4.2.2 Download the source code

$ cd $HOME
$ mkdir devel
$ cd devel
$ git clone https://github.com/OP-TEE/optee_os.git

4.2.3 Build

$ cd $HOME/devel/optee_os
$ CROSS_COMPILE=arm-linux-gnueabihf- make

4.2.4 Compiler flags

To be able to see the full command when building you could build using following flag:

$ make V=1

To enable debug builds use the following flag:

$ make DEBUG=1

OP-TEE supports a couple of different levels of debug prints for both TEE core itself and for the Trusted Applications. The level ranges from 1 to 4, where four is the most verbose. To set the level you use the following flag:

$ make CFG_TEE_CORE_LOG_LEVEL=4

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4.4 STMicroelectronics boards

Currently OP-TEE is supported on Orly-2 (b2020-h416) and Cannes family (b2120 both h310 and h410 chip).

4.4.1 Get the compiler for Orly-2

Will be written soon.

4.4.2 Download the source code

See section "4.2.2 Download the source code".

4.4.3 Build for Orly-2

For Orly-2 do as follows

$ PLATFORM=stm-orly2 CROSS_COMPILE=arm-linux-gnueabihf- make

For Cannes family do as follows

$ PLATFORM=stm-cannes CROSS_COMPILE=arm-linux-gnueabihf- make

4.4.4 Prepare and install the images

Will be written soon.

4.4.5 Boot and run the software

Will be written soon.

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4.5 Allwinner A80

4.5.1 Locked versus unlocked A80 boards

Important! All A80 boards sold to the general public are boards where secure side has been locked down, which means that you cannot use them for secure side development, i.e, it will not be possible to put OP-TEE on those devices. If you want to use A80 board for secure side development, then you will need to talk to Allwinner directly and ask if it is possible get a device from them.

4.5.2 Get the compiler and source

Follow the instructions in the "4.2 Basic setup".

4.5.3 Build

$ cd optee_os
$ export PLATFORM=sunxi
$ export CROSS_COMPILE=arm-linux-gnueabihf-
$ make

4.5.4 Prepare the images to run on A80 Board

Download Allwinner A80 platform SDK, the SDK refers to Allwinner A80 platform SDK root directory. A80 SDK directory tree looks like this:

SDK/
    Android
    lichee

Android contains all source code related to Android and lichee contains the bootloader and Linux kernel.

4.5.4.1 Copy OP-TEE output to package directory

Copy the OP-TEE output binary to SDK/lichee/tools/pack/sun9i/bin

$ cd optee_os
$ cp ./out/arm32-plat-sunxi/core/tee.bin SDK/lichee/tools/pack/sun9i/bin

4.5.4.2 Build Linux kernel

In the lichee directory, run the following commands:

$ cd SDK/lichee
$ ./build.sh

4.5.4.3 Build Android

In the Android directory, run the following commands:

$ cd SDK/android
$ extract-bsp
$ make -j

4.5.4.4 Create the Android image

In the Android directory, run the following commands:

$ cd SDK/android
$ pack

The output image will been signed internally when packed. The output image name is a80_android_board.img.

4.5.4.5 Download the Android image

Use Allwinner PhoenixSuit tool to download to A80 board. Choose the output image(a80_android_board.img), select download and wait for the download to complete.

4.5.5 Boot and run the software on A80 Board

When the host platform is Windows, use a console application to connect A80 board uart0. In the console window, You can install OP-TEE linux kernel driver optee.ko, load OP-TEE-Client daemon tee-supplicant and run the example "hello world" Trusted Application, do this by running:

$ insmod /system/vendor/modules/optee.ko
$ /system/bin/tee-supplicant &
$ /system/bin/tee-helloworld

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4.6 Freescale MX6UL EVK

Build:

    PLATFORM_FLAVOR=mx6ulevk make PLATFORM=imx
    ${CROSS_COMPILE}-objcopy -O binary out/arm-plat-imx/core/tee.elf optee.bin
    copy optee.bin to the first partition of SD card which is used for boot.

Run using U-Boot:

    run loadfdt;
    run loadimage;
    fatload mmc 1:1 0x9c100000 optee.bin;
    run mmcargs;
    bootz ${loadaddr} - ${fdt_addr};

Note: CAAM is not implemented now, this will be added later.

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5. repo manifests

A Git repository is available at https://github.com/OP-TEE/manifest where you will find XML-files for use with the Android 'repo' tool.

5.1. Install repo

Follow the instructions under the "Installing Repo" section here.

5.2. Get the source code

First ensure that you have the necessary Ubuntu packages installed, see 4.1 Prerequisites (this is the only important step from section 4 in case you are setting up any of the target devices mentioned below).

$ mkdir -p $HOME/devel/optee
$ cd $HOME/devel/optee
$ repo init -u https://github.com/OP-TEE/manifest.git -m ${TARGET}.xml [-b ${BRANCH}]
$ repo sync

5.2.1 Targets

Target	Latest	Stable
QEMU	default.xml	default_stable.xml
FVP	fvp.xml	fvp_stable.xml
HiKey	hikey.xml	hikey_stable.xml
MediaTek MT8173 EVB Board	mt8173-evb.xml	mt8173-evb_stable.xml
ARM Juno board	juno.xml	juno_stable.xml

5.2.2 Branches

Currently we are only using one branch, i.e, the master branch.

5.2.3 Get the toolchains

$ cd build
$ make toolchains

Notes

• The folder could be at any location, we are just giving a suggestion by saying $HOME/devel/optee.
• repo sync can take an additional parameter -j to sync multiple remotes. For example repo sync -j3 will sync three remotes in parallel.

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5.3. QEMU

After getting the source and toolchain, just run (from the build folder)

$ make all run

and everything should compile and at the end QEMU should start.

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5.4. FVP

After getting the source and toolchain you must also obtain Foundation Model (link) binaries and untar it to the forest root, then just run (from the build folder)

$ make all run

and everything should compile and at the end FVP should start.

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5.5. HiKey

After getting the source and toolchain, just run (from the build folder)

$ make all

After that connect the board and flash the binaries by running:

$ make flash

(more information about how to flash individual binaries could be found here)

The board is ready to be booted.

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5.6. MT8173-EVB

After getting the source and toolchain, just run (from the build folder)

$ make all run

When < waiting for device > prompt appears, press reset button and the flashing procedure should begin.

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5.7 Juno

After getting the source and toolchain, just run (from the build folder)

$ make all

Enter the firmware console on the juno board and press enter to stop the auto boot flow

ARM V2M_Juno Firmware v1.3.9
Build Date: Nov 11 2015

Time :  12:50:45
Date :  29:03:2016

Press Enter to stop auto boot...

Enable ftp at the firmware prompt

Cmd> ftp_on
Enabling ftp server...
 MAC address: xxxxxxxxxxxx

 IP address: 192.168.1.158

 Local host name = V2M-JUNO-A2

Flash the binary by running (note the IP address from above):

make JUNO_IP=192.168.1.158 flash

Once the binaries are transferred, reboot the board:

Cmd> reboot

5.7.1 Update flash and its layout

The flash in the board may need to be updated for the flashing above to work. If the flashing fails or if ARM-TF refuses to boot due to wrong version of the SCP binary the flash needs to be updated. To update the flash please follow the instructions at Using Linaro's deliverable on Juno selecting one of the zips under "4.1 Prebuilt configurations" flashing it as described under "5. Running the software".

5.7.2 GlobalPlatform testsuite support

Warning :

Depending on the Juno pre-built configuration, the built ramdisk.img size with GlobalPlatform testsuite may exceed its pre-defined Juno flash memory reserved location (image.txt file). In that case, you will need to extend the Juno flash block size reserved location for the ramdisk.img in the image.txt file accordingly and follow the instructions under "5.7.1 Update flash and its layout".

Example with juno-latest-busybox-uboot.zip:

The current ramdisk.img size with GlobalPlatform testsuite is 8.6 MBytes.

Updated file is /JUNO/SITE1/HBI0262B/images.txt (limited to 8.3 MB)

NOR4UPDATE: AUTO                 ;Image Update:NONE/AUTO/FORCE
NOR4ADDRESS: 0x01800000          ;Image Flash Address
NOR4FILE: \SOFTWARE\ramdisk.img  ;Image File Name
NOR4NAME: ramdisk.img
NOR4LOAD: 00000000               ;Image Load Address
NOR4ENTRY: 00000000              ;Image Entry Point

Extended to 16MB

NOR4UPDATE: AUTO                 ;Image Update:NONE/AUTO/FORCE
NOR4ADDRESS: 0x01000000          ;Image Flash Address
NOR4FILE: \SOFTWARE\ramdisk.img  ;Image File Name
NOR4NAME: ramdisk.img
NOR4LOAD: 00000000               ;Image Load Address
NOR4ENTRY: 00000000              ;Image Entry Point

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5.8 Tips and tricks

5.8.1 Reference existing project to speed up repo sync

Doing a repo init, repo sync from scratch can take a fair amount of time. The main reason for that is simply because of the size of some of the gits we are using, like for the Linux kernel and EDK2. With repo you can reference an existing forest and by doing so you can speed up repo sync to instead taking ~20 seconds instead of an hour. The way to do this are as follows.

1. Start by setup a clean forest that you will not touch, in this example, let us call that optee-ref and put that under for $HOME/devel/optee-ref. This step will take roughly an hour.
2. Then setup a cronjob (crontab -e) that does a repo sync in this folder particular folder once a night (that is more than enough).
3. Now you should setup your actual tree which you are going to use as your working tree. The way to do this is almost the same as stated in the instructions above, the only difference is that you reference the other local forest when running repo init, like this

   repo init -u https://github.com/OP-TEE/manifest.git --reference /home/jbech/devel/optee-ref

4. The rest is the same above, but now it will only take a couple of seconds to clone a forest.

Normally step 1 and 2 above is something you will only do once. Also if you ignore step 2, then you will still get the latest from official git trees, since repo will also check for updates that aren't at the local reference.

5.8.2. Use ccache

ccache is a tool that caches build object-files etc locally on the disc and can speed up build time significantly in subsequent builds. On Debian-based systems (Ubuntu, Mint etc) you simply install it by running:

$ sudo apt-get install ccache

The helper makefiles are configured to automatically find and use ccache if ccache is installed on your system, so other than having it installed you don't have to think about anything.

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6. Load driver, tee-supplicant and run xtest

To actually run something on a device you need to probe the kernel driver for OP-TEE, run tee-supplicant. This is the same for almost all platforms, so when a device has booted, then run

$ modprobe optee_armtz
$ tee-supplicant &

In case you want to try run something triggering both normal and secure side code you could run xtest (the main test suite for OP-TEE), run

$ xtest

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7. Coding standards

In this project we are trying to adhere to the same coding convention as used in the Linux kernel (see CodingStyle). We achieve this by running checkpatch from Linux kernel. However there are a few exceptions that we had to make since the code also follows GlobalPlatform standards. The exceptions are as follows:

• CamelCase for GlobalPlatform types are allowed.
• And we also exclude checking third party code that we might use in this project, such as LibTomCrypt, MPA, newlib (not in this particular git, but those are also part of the complete TEE solution). The reason for excluding and not fixing third party code is because we would probably deviate too much from upstream and therefore it would be hard to rebase against those projects later on (and we don't expect that it is easy to convince other software projects to change coding style).

7.1 checkpatch

Since checkpatch is licensed under the terms of GNU GPL License Version 2, we cannot include this script directly into this project. Therefore we have written the Makefile so you need to explicitly point to the script by exporting an environment variable, namely CHECKPATCH. So, suppose that the source code for the Linux kernel is at $HOME/devel/linux, then you have to export like follows:

$ export CHECKPATCH=$HOME/devel/linux/scripts/checkpatch.pl

thereafter it should be possible to use one of the different checkpatch targets in the Makefile. There are targets for checking all files, checking against latest commit, against a certain base-commit etc. For the details, read the Makefile.