查看“STM32MP15 OP-TEE”的源代码

== Purpose ==
This article describes the process used for building several OP-TEE components from sources and deploying them the target.<br>

The build example is based on the OpenSTLinux [[STM32MP1_Developer_Package|Developer Package]] or [[STM32MP1_Distribution_Package|Distribution Package]], and also presents build instructions for a bare environment.

== Overview ==
OP-TEE is a trusted execution environment for Arm<sup>&reg;</sup>v7-A and Arm<sup>&reg;</sup>v8-A platforms.
OP-TEE is made of several components described in [[OP-TEE_overview#Architecture|OP-TEE architecture overview]].<br>

OP-TEE components generate boot images and files stored in the filesystem embedded in the target.

* OP-TEE OS generates 3 boot image files to be loaded in the platform boot media, in the predefined partitions. The generated boot images include a [[STM32MP15_secure_boot#STM32_Header|STM32 binary header]] enabling the use of the authenticated boot and flash programming facilities.

* OP-TEE client (package optee_client) can be built to generate non-secure services for the OP-TEE OS. The files generated from optee_client build are stored in the embedded filesystem.

* OP-TEE project releases other packages intended for test and demonstration. These can be built and embedded in the target filesystem. Building optee_examples and optee_test generates client and trusted applications together with libraries which are all stored in the target filesystem. Note the OP-TEE Linux driver is built into the Linux kernel image and is part of the OP-TEE ecosystem.

OP-TEE can be embedded in the STM32MP1 platform for the ST trusted configuration.<br>

== Build with the Distribution Package ==

The [[STM32MP1_Distribution_Package|Distribution Package]] provides means to build the following OP-TEE components from their related bitbake target:

 {{PC$}} bitbake optee-os-stm32mp                # OP-TEE core firmware
 {{PC$}} bitbake optee-os-sdk-stm32mp            # OP-TEE development kit for Trusted Applications
 {{PC$}} bitbake optee-client                    # OP-TEE client
 {{PC$}} bitbake optee-test                      # OP-TEE test suite (optional)
 {{PC$}} bitbake optee-examples                  # TA and CA examples

[[STM32MP1_Distribution_Package|Distribution Package]] build process includes fetching the source files, compiling them and installing them to the target images.

The Yocto recipes for the OP-TEE packages can be found in:<br>
 meta-st/meta-st-stm32mp/recipes-security/optee/optee-os-stm32mp*
 meta-st/meta-st-openstlinux/recipes-security/optee/optee-client*
 meta-st/meta-st-openstlinux/recipes-security/optee/optee-examples*
 meta-st/meta-st-openstlinux/recipes-security/optee/optee-test*

== Build with the Developer Package or a Bare Environment ==

Both [[STM32MP1_Developer_Package|Developer Package]] and bare build environments expect you to fetch/download the OP-TEE package source file trees in order to build the embedded binary images.

The instruction set below assumes all OP-TEE package source trees are available in the base directory referred as <sources>/. The source files are available from the github repositories:
 {{PC$}} cd <sources>/
 {{PC$}} git clone https://github.com/STMicroelectronics/optee_os.git
 {{PC$}} git clone https://github.com/OP-TEE/optee_client.git
 {{PC$}} git clone https://github.com/OP-TEE/optee_test.git
 {{PC$}} git clone https://github.com/linaro-swg/optee_examples.git
 {{PC$}} ls -1 <sources>/
 optee_client
 optee_examples
 optee_os
 optee_test
 {{PC$}} 

{{Warning|The STM32MP1 platform is not yet fully merged in the official OP-TEE repository <ref name=OP-TEE/optee_os>https://github.com/OP-TEE/optee_os</ref> hence the URL provided above refers to the ST distribution <ref name=STMicroelectronics/optee_os>https://github.com/STMicroelectronics/optee_os</ref>}}

{{InternalInfo |
Download optee_os source code from the internal Git:
 {{PC$}} git clone ssh://gerrit.st.com:29418/mpu/oe/optee/optee_os.git
}}

=== Initialize the cross compile environment ===

The compilation toolchain provided by the [[STM32MP1_Developer_Package|Developer Package]] can be used, refer to [[Cross-compile with OpenSTLinux SDK|Setup Cross Compile Environment]].

Alternatively other bare toolchains can be used to build the OP-TEE '''secure''' parts. In such case, the instructions below expect the toolchain to be part of the '''PATH''' and its prefix is defined by '''CROSS_COMPILE'''. One can use something like:
 {{PC$}} export PATH=<path-to-toolchain>:$PATH
 {{PC$}} export CROSS_COMPILE=<toolchain-prefix>-

=== Build OP-TEE OS ===

==== Developer Package SDK ====
The OP-TEE OS can be built from the [[STM32MP1_Developer_Package|Developer Package]] '''Makefile.sdk''' script that is present in the tarball. It automatically sets the proper configuration for the OP-TEE OS build. To build from shell command:<br>
{{ReviewsComments|-- [[User:Arnaud Pouliquen|Arnaud Pouliquen]] ([[User talk:Arnaud Pouliquen|talk]]) 18:51, 14 April 2020 (CEST)<br /> probably to update. for instance no Makefile.sdk if code get from internal ST repo  ( i don't check external repo or distrib...). here are the commands i use<br>
  unset LDFLAGS<br>
  <nowiki>make PLATFORM=stm32mp1 CFG_EMBED_DTB_SOURCE_FILE=stm32mp157c-<board>.dts CFG_SECURE_DT=stm32mp157c-<board> O=out all -j1 comp-cflagscore=--sysroot=$SDKTARGETSYSROOT</nowiki>
 }}
 {{PC$}} make -f Makefile.sdk CFG_SECURE_DT=stm32mp157c-<board>

==== Bare Environment ====
Alternatively one can also build OP-TEE OS based a bare cross compilation toolchains, for example for the stm32mp157c-ev1 board:
 {{PC$}} cd <optee-os>
 {{PC$}} make PLATFORM=stm32mp1 \
            CFG_SECURE_DT=stm32mp157c-ev1 \
            CFG_TEE_CORE_LOG_LEVEL=2 O=out all

==== Generated Files ====
The 3 OP-TEE boot images are generated at following paths:
 <optee-os>/out/core/tee-header_v2.stm32
 <optee-os>/out/core/tee-pageable_v2.stm32
 <optee-os>/out/core/tee-pager_v2.stm32

One can get The configuration directives used for the build are available in this file:
 <optee-os>/out/conf.mk

The build also generates a development kit used to build Trusted Application binaries:
 <optee-os>/out/export-ta_arm32/

==== Details on build directives ====

Mandatory directives to build OP-TEE OS:
* '''PLATFORM=stm32mp1''': builds an stm32mp1 platform
* '''CFG_SECURE_DT=<device-tree-source-file>''': in-tree (core/arch/arm/dts/) device tree filename without its '''.dts''' extension.

Common optional directives:
* '''CFG_TEE_CORE_DEBUG={n|y}''': disable/enable debug support
* '''CFG_TEE_CORE_LOG_LEVEL={0|1|2|3|4}''': define the trace level (0: no trace, 4: overflow of traces)
* '''CFG_UNWIND={n|y}''': disable/enable stack unwind support

Note: internal memory size constrains the debug support level that can be provided.

==== Troubleshoot ====
The [[STM32MP1_Developer_Package|Developer Package]] toolchain may report dependency error in the traces such as:
 {{PC$}} make PLATFORM=stm32mp1 ...
 arm-openstlinux_weston-linux-gnueabi-ld.bfd: cannot find libgcc.a: No such file or directory

To overcome the issue, add the directive '''comp-cflagscore=--sysroot=$SDKTARGETSYSROOT'''. I.e:
 {{PC$}} cd <optee-os>
 {{PC$}} make PLATFORM=stm32mp1 \
            CFG_SECURE_DT=stm32mp157c-ev1 \
            CFG_TEE_CORE_LOG_LEVEL=2 \
            comp-cflagscore=--sysroot=$SDKTARGETSYSROOT \
            O=out all
{{ReviewsComments|-- [[User:Arnaud Pouliquen|Arnaud Pouliquen]] ([[User talk:Arnaud Pouliquen|talk]]) 18:51, 14 April 2020 (CEST)<br />  add link issue<br>

 LD      out/core/tee.elf
 arm-ostl-linux-gnueabi-ld.bfd: unrecognized option '-Wl,-O1'
 arm-ostl-linux-gnueabi-ld.bfd: use the --help option for usage information
 core/arch/arm/kernel/link.mk:156: recipe for target 'out/core/tee.elf' failed
 make: *** [out/core/tee.elf] Error 1

solution: unset LDFLAGS
}}
=== Build commands for other OP-TEE components ===

This section describes how the several OP-TEE components (excluding OP-TEE OS described in above section) can be built. All those components generate files targeting the embedded Linux OS based filesystem (i.e the rootfs). These files are the secure Trusted Applications (TAs) binaries as well as non-secure Client Applications (CAs), libraries and test files.

There are several ways to build the OP-TEE components. The examples given below refer to OP-TEE client, test and examples source file tree paths as
<optee-client>, <optee-test> and <optee-examples>.

Building these components expect, at least for the trusted applications, that the OP-TEE OS was built and the generated TA development kit is available at <optee-os>/out/export-ta_arm32/.

It is recommended to use CMake for building the Linux userland part whereas secure world binaries (TAs) must be build from their GNU makefiles as the OP-TEE project has not yet ported the secure world binaries build process over CMake.

==== Build the secure components====

Build the TAs: This step expects OP-TEE OS is built to generate the 32bit TA development kit. Assuming OP-TEE OS was built at path <optee-os>/out, the TA development kit is available from path <optee-os>/out/export-ta_arm32/.

Instructions below build and copy the Trusted Application binaries to a local '''./target/''' directory that can be used to populate the target
filesystem.

 {{PC$}} export TA_DEV_KIT_DIR=$PWD/optee_os/out/export-ta_arm32
 {{PC$}} mkdir -p ./target/lib/optee_armtz
 {{PC$}} for f in optee_test/ta/*/Makefile; do \
             make -C `dirname $f` O=out; \
             cp -f `dirname $f`/out/*.ta ./target/lib/optee_armtz; \
       done

Content in local directory '''./target/''' are the TA binary files: 

 {{PC$}} tree target/
 target
 └── lib
   └── optee_armtz
    ├── 614789f2-39c0-4ebf-b235-92b32ac107ed.ta
    ├── 731e279e-aafb-4575-a771-38caa6f0cca6.ta
    └── (...)

These files need to be copied to the the target filesystem.

==== Build the non-secure components====

Download the OP-TEE source files in a base directory and create a '''CMakeLists.txt''' file in the base directory that lists all package to be built through CMake. For example:

 {{PC$}} ls
 optee_client
 optee_examples
 optee_os
 optee_test
 CMakeLists.txt
 {{PC$}} cat CMakeLists.txt
 add_subdirectory (optee_client)
 add_subdirectory (optee_test)
 add_subdirectory (optee_examples)
 {{PC$}} 

From base directory, run '''cmake''' then '''make'''. The example below also creates the tree file system '''./target/''' that is populated with files generated that need to be installed in the target file system.<br>
Note this examples also sets the toolchain environment:

 {{PC$}} cmake -DOPTEE_TEST_SDK=$PWD/optee_os/out/export-ta_arm32 \
             -DCMAKE_INSTALL_PREFIX=  -DCMAKE_BUILD_TYPE=Release -DBUILD_SHARED_LIBS=y
 {{PC$}} make
 {{PC$}} make DESTDIR=target install 

Note the empty '''CMAKE_INSTALL_PREFIX''' value to get thing installed from root '''/''', not from '''/usr/'''.
'''DESTDIR=target''' makes the embedded files be populated in the local '''./target/''' directory.

Note also that stm32mp15 expects tool '''tee-supplicant''' to be located in directory '''/usr/bin''' whereas CMake installs it in directory '''/usr/sbin'''. To overcome this issue, one can build a link to the effective location, i.e:

 {{PC$}} ln -s ../bin/tee-supplicant target/sbin/tee-supplicant

Once done, local directory '''./target/''' contains the files to be copied in the target filesystem.

 {{PC$}} tree target/
 target/
 ├── bin
 │   ├── benchmark
 │   ├── optee_example_acipher
 │   ├── optee_example_aes
 │   ├── optee_example_hello_world
 │   ├── optee_example_hotp
 │   ├── optee_example_random
 │   ├── optee_example_secure_storage
 │   ├── tee-supplicant
 │   └── xtest
 ├── include
 │   ├── tee_bench.h
 │   ├── tee_client_api_extensions.h
 │   ├── tee_client_api.h
 │   └── teec_trace.h
 ├── lib
 │   ├── libteec.so -> libteec.so.1
 │   ├── libteec.so.1 -> libteec.so.1.0.0
 │   └── libteec.so.1.0.0
 │   └── optee_armtz
 │       └── (...)                 # This directory was previously filled with TAs
 └── sbin
     └── tee-supplicant -> ../bin/tee-supplicant

== Update software on board ==

The OP-TEE OS boot images shall be loaded into the related partitions of the boot media.<br>
The other OP-TEE images are stored in the target filesystem.<br>

For example, if using an SD card as target boot media, the card can be plugged in its PC card reader and the images copied. OP-TEE core boot images can be loaded using tool '''dd''' while other files can be simply copied into the mounted rootfs.

=== Update OP-TEE Core Boot Partitions in an SD card ===

If booting the target from an SD card, the core OP-TEE firmware can be updated using the tool '''dd'''.<br>
Plug the SD card into the computer slot reader and copy the binary to the dedicated partition; on an SDCard/USB disk the OP-TEE OS boot partitions are partition 4 to 6.

The target partition is located from the partition labels of the SD card, i.e:
 {{PC$}} ls -l /dev/disk/by-partlabel/
 total 0
 lrwxrwxrwx 1 root root 10 Jan 28 16:35 bootfs -> ../../sdd7        (Linux kernel boot filesystem)
 lrwxrwxrwx 1 root root 10 Jan 28 16:35 fsbl1 -> ../../sdd1         (part#1 is TF-A)
 lrwxrwxrwx 1 root root 10 Jan 28 16:35 fsbl2 -> ../../sdd2         (part#2 is TF-A backup)
 lrwxrwxrwx 1 root root 10 Jan 28 16:35 rootfs -> ../../sdd9        (Linux kernel root filesystem)
 lrwxrwxrwx 1 root root 10 Jan 28 16:35 ssbl -> ../../sdd3          (part#3# is U-Boot)
 lrwxrwxrwx 1 root root 10 Jan 28 16:35 teed -> ../../sdd5          (OP-TEE OS paged data)
 lrwxrwxrwx 1 root root 10 Jan 28 16:35 teeh -> ../../sdd4          (OP-TEE OS header image)
 lrwxrwxrwx 1 root root 10 Jan 28 16:35 teex -> ../../sdd6          (OP-TEE OS resident core)
 lrwxrwxrwx 1 root root 11 Jan 28 16:35 userfs -> ../../sdd10       (Linux kernel user filesystem)
 lrwxrwxrwx 1 root root 10 Jan 28 16:35 vendorfs -> ../../sdd8      (Linux kernel vendor filesystem)

For the SD card described above, the 3 OP-TEE core images can then be updated with:
 {{PC$}} dd conv=fdatasync of=/dev/sdd4 if=<optee-os>/out/core/tee-header_v2.stm32
 {{PC$}} dd conv=fdatasync of=/dev/sdd5 if=<optee-os>/out/core/tee-pageable_v2.stm32
 {{PC$}} dd conv=fdatasync of=/dev/sdd6 if=<optee-os>/out/core/tee-pager_v2.stm32 

=== Update OP-TEE Linux Files in a SD card ===
The OP-TEE files that need to be copied to the target filesystem were installed in a local directory '''./target/'''.

They can now be copied to the target SD card rootfs partition once the SD card is plugged to the host computer and its filesystems are mounted in the host, i.e
 {{PC$}} cp -ar target/* /media/$USERNAME/rootfs/

=== Update via USB mass storage on U-boot ===
See [[How to use USB mass storage in U-Boot]] and follow the previous sections to 
load binary files '''tee-*_v2.stm32''' onto target partitions.

=== Update your boot device (including SD card on the target) ===
Refer to the [[STM32CubeProgrammer]] documentation to update your target.

== References ==
<references />

<noinclude>
{{PublicationRequestId | 10619 | 2019-02-01 | Gregorys}}
[[Category:OP-TEE secure OS]]
</noinclude>