xref/optee_os/README.md

# OP-TEE Trusted OS
## Contents
1. [Introduction](#1-introduction)
2. [License](#2-license)
3. [Platforms supported](#3-platforms-supported)
    3. [Development board for community user] (#31-development-board-for-community-user)
4. [Get and build OP-TEE software](#4-get-and-build-op-tee-software)
    4. [Prerequisites](#41-prerequisites)
    4. [Basic setup](#42-basic-setup)
    4. [ARM Juno board](#43-arm-juno-board)
    4. [STMicroelectronics boards](#44-stmicroelectronics-boards)
    4. [Allwinner A80](#45-allwinner-a80)
    4. [Freescale MX6UL EVK](#46-freescale-mx6ul-evk)
5. [repo manifests](#5-repo-manifests)
	5. [Install repo](#51-install-repo)
	5. [Get the source code](#52-get-the-source-code)
		5. [Targets](#521-targets)
		5. [Branches](#522-branches)
		5. [Get the toolchains](#523-get-the-toolchains)
	5. [QEMU](#53-qemu)
	5. [FVP](#54-fvp)
	5. [HiKey](#55-hikey)
	5. [MT8173-EVB](#56-mt8173-evb)
	5. [Tips and tricks](#57-tips-and-tricks)
		5. [Reference existing project to speed up repo sync](#571-reference-existing-project-to-speed-up-repo-sync)
		5. [Use ccache](#572-use-ccache)
6. [Load driver, tee-supplicant and run xtest](#6-load-driver-tee-supplicant-and-run-xtest)
7. [Coding standards](#7-coding-standards)
	7. [checkpatch](#71-checkpatch)

# 1. Introduction
The `optee_os git`, contains the source code for the TEE in Linux using the
ARM&reg; TrustZone&reg; 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](Notice.md) file.

The Trusted OS is accessible from the Rich OS (Linux) using the
[GlobalPlatform TEE Client API Specification v1.0](http://www.globalplatform.org/specificationsdevice.asp),
which also is used to trigger secure execution of applications within the TEE.

---
## 2. License
The software is distributed mostly under the
[BSD 2-Clause](http://opensource.org/licenses/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](http://opensource.org/licenses/BSD-3-Clause) or public domain
licenses.

---
## 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](documentation/build_system.md). Some
platforms have different sub-maintainers, please refer to the file
[MAINTAINERS.md](MAINTAINERS.md) for contact details for various platforms.

<!-- Please keep this list sorted in alphabetic order -->
| Platform | Composite PLATFORM flag | Publicly available? |
|----------|-------------------------|---------------------|
| [Allwinner A80 Board](http://www.allwinnertech.com/en/clq/processora/A80.html)|`PLATFORM=sunxi`| No |
| [ARM Juno Board](http://www.arm.com/products/tools/development-boards/versatile-express/juno-arm-development-platform.php) |`PLATFORM=vexpress-juno`| Yes |
| [FSL ls1021a](http://www.freescale.com/tools/embedded-software-and-tools/hardware-development-tools/tower-development-boards/mcu-and-processor-modules/powerquicc-and-qoriq-modules/qoriq-ls1021a-tower-system-module:TWR-LS1021A?lang_cd=en)|`PLATFORM=ls-ls1021atwr`| Yes |
| [FSL i.MX6 UltraLite EVK Board](http://www.freescale.com/products/arm-processors/i.mx-applications-processors-based-on-arm-cores/i.mx-6-processors/i.mx6qp/i.mx6ultralite-evaluation-kit:MCIMX6UL-EVK) |`PLATFORM=imx`| Yes |
| [ARM Foundation FVP](http://www.arm.com/fvp) |`PLATFORM=vexpress-fvp`| Yes |
| [HiKey Board (HiSilicon Kirin 620)](https://www.96boards.org/products/hikey)|`PLATFORM=hikey`| Yes |
| [MediaTek MT8173 EVB Board](http://www.mediatek.com/en/products/mobile-communications/tablet/mt8173)|`PLATFORM=mediatek-mt8173`| No |
| [QEMU](http://wiki.qemu.org/Main_Page) |`PLATFORM=vexpress-qemu_virt`| Yes |
| [STMicroelectronics b2120 - h310 / h410](http://www.st.com/web/en/catalog/mmc/FM131/SC999/SS1628/PF258776) |`PLATFORM=stm-cannes`| No |
| [STMicroelectronics b2020-h416](http://www.st.com/web/catalog/mmc/FM131/SC999/SS1633/PF253155?sc=internet/imag_video/product/253155.jsp)|`PLATFORM=stm-orly2`| No |
| [Texas Instruments DRA7xx](http://www.ti.com/product/DRA746)|`PLATFORM=ti-dra7xx`| Yes |

### 3.1 Development board for community user
For community users, we suggest using [HiKey board](https://www.96boards.org/products/ce/hikey/)
as development board. It provides detailed documentation including chip
datasheet, board schematics, source code, binaries etc on the download link at
the website.

---
## 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](https://source.android.com/source/downloading.html), so for some targets
you will see that we are using repo ([section 5](#5-repo-manifests)) and for
others we are still using the shell script based setup
([section 4](#4-get-and-build-op-tee-software)), please see this transitions as
work in progress.

---
### 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
```

---
### 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](https://github.com/OP-TEE/build/blob/master/toolchain.mk)
and then look at the targets makefile (see [build.git](https://github.com/OP-TEE/build))
to find out where the respective toolchain will be used. For example in the
[QEMU makefile](https://github.com/OP-TEE/build/blob/master/qemu.mk#L12-L15) 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
```

---
### 4.3 ARM Juno board
**Warning!** This setup is currently broken, `bl30.bin` and `bl33.bin` doesn't
exist on the URLs stated any longer. We are working with a fix and once ready,
we will replace this section and instead put Juno board within the repo
section below. Until resolved, we will keep the information below for reference.

+ The script `setup_juno_optee.sh` script provides a coherent set of components
(OP-TEE client, driver, OS, Linux kernel version 3-16.0-rc5)

+ Futures releases will align the Juno setup with other OP-TEE supported
  platforms:

	+ Linux kernel version alignment (3.18-rc1) with QEMU/FVP (DMA_BUF API change).
	+ Will need arch/arm/Kconfig patch(es) (i.e DMA_SHARED_BUFFER etc...).

+ Temporary patch files required for linux kernel and Juno DTB definition (found
  in the `./scripts` folder)

	+ `config.linux-linaro-tracking.a226b22057c22b433caafc58eeae6e9b13ac6c8d.patch`
	+ `juno.dts.linux-linaro-tracking.a226b22057c22b433caafc58eeae6e9b13ac6c8d.patch`

#### 4.3.1 Prerequisites for Juno board
+ Download pre-built binaries (please see "Known issues" below)

	+ Juno boards pre-built binary `bl30.bin` (SCP runtime)
	+ Juno boards pre-built binary `bl33.bin` (UEFI)
	+ Download at &rarr; https://releases.linaro.org/members/arm/platforms/latest


#### 4.3.2 Download the source code for Juno board
```
$ wget https://raw.githubusercontent.com/OP-TEE/optee_os/master/scripts/setup_juno_optee.sh
$ chmod 711 setup_juno_optee.sh
$ ./setup_juno_optee.sh
```

#### 4.3.3 Build
List of helper scripts generated during installation:

| Script | Explanation |
|--------|--------|
| `build_atf_opteed.sh` | This is used to build ARM-Trusted-Firmware and must be called when you have updated any component that are included in the FIP (like for example OP-TEE os). |
| `build_linux.sh` | This is used to build the Linux Kernel. |
| `build_normal.sh` | This is a pure helper script that build all the normal world components (in correct order). |
| `build_optee_client.sh` | This will build OP-TEEs client library. |
| `build_optee_linuxdriver.sh` | This will build OP-TEEs Linux Kernel driver (as a module). |
| `build_optee_os.sh` | Builds the Trusted OS itself |
| `build_optee_tests.sh` | This will build the test suite (pay attention to the access needed). |
| `build_secure.sh` | This is the helper script for the secure side that will build all secure side components in the correct order. |
| `clean_gits.sh` | This will clean all gits. Beware that it will not reset the commit to the one used when first cloning. Also note that it will only clean git's. |

Run the scripts in the following order:

```
$ ./build_secure.sh
$ ./build_normal.sh
```

#### 4.3.4 Booting up the Juno board

+ Update the embedded flash memory (path: `JUNO/SOFTWARE`):

	+ `bl1.bin`
	+ `fip.bin`
	+ `Image`
	+ `juno.dtb`

+ Copy OP-TEE binaries on the filesystem(*) located on the external USB key:

	+ user client libraries: `libteec.so*`
	+ supplicant: `tee-supplicant`
	+ driver modules: `optee.ko optee_armtz.ko`
	+ CA: `xtest`
	+ TAs: `*.ta`

+ Connect the USB flash drive (containing the filesystem) on any connector of
  the rear panel

+ Connect a serial terminal (`115200, 8, n, 1`) to the upper 9-pin (`UART0`)
  connector.

+ Connect the 12V power, then press the red button on the rear panel.

Note:
The default configuration is to automatically boot a Linux kernel, which expects
to find a root filesystem on `/dev/sda1` (any one of the rear panel USB ports).

Download a minimal filesytem at &rarr;
http://releases.linaro.org/14.02/openembedded/aarch64/linaro-image-minimal-genericarmv8-20140223-649.rootfs.tar.gz

UEFI offers a 10 second window to interrupt the boot sequence by pressing a key
on the serial terminal, after which the kernel is launched.

Once booted you will get the prompt:
```
root@genericarmv8:~#
```

#### 4.3.5 Run OP-TEE on the Juno board
Write in the console:
```
root@genericarmv8:~# modprobe optee_armtz
root@genericarmv8:~# tee-supplicant &
```
Now everything has been set up and OP-TEE is ready to be used.

#### 4.3.6 Known issues and limitations
* `bl30.bin` (SCP) and `bl33.bin` (UEFI) are not available on previous download
  location and therefore this setup is currently not working. We are working
  with sorting out this issue and once done, we will start using repo manifests
  for Juno also.
* Not all USB flash drives seems to work, so we recommend using USB memory 3.0
  formatted with an ext3/ext4 filesystem

---
### 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
<!-- All magic with STM and so on must be stated here. -->
Will be written soon.

---
### 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](https://github.com/OP-TEE/optee_os/blob/master/MAINTAINERS.md)
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
```

---
### 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.

---
## 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](https://source.android.com/source/downloading.html).

### 5.2. Get the source code
First ensure that you have the necessary Ubuntu packages installed, see [4.1
Prerequisites](#41-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` |

#### 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**<br>
* 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.

---
### 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.

---
### 5.4. FVP
After getting the source and toolchain you must also obtain Foundation Model
([link](http://www.arm.com/products/tools/models/fast-models/foundation-model.php))
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.

---
### 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](https://github.com/96boards/documentation/wiki/HiKeyUEFI#flash-binaries-to-emmc-))

The board is ready to be booted.

---
### 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.

---
### 5.7 Tips and tricks
#### 5.7.1 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.

#### 5.7.2. 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.

---
## 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
```

---
## 7. Coding standards
In this project we are trying to adhere to the same coding convention as used in
the Linux kernel (see
[CodingStyle](https://www.kernel.org/doc/Documentation/CodingStyle)). We achieve this by running
[checkpatch](http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/scripts/checkpatch.pl)
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](Makefile). There are targets for checking all files, checking
against latest commit, against a certain base-commit etc. For the details, read
the [Makefile](Makefile).