Provide Raspberry Pi #aarch64 cross-compile instructions

[marianopeck]

System information

• TensorFlow version (you are using): 1.13.1
• Are you willing to contribute it (Yes/No): yes, at least as a tester

Describe the feature and the current behavior/state.

There is no pre-build binary for Raspberry Pi / ARM and the instructions to build from scratch here. However, there is nothing for any kind of SBC (like Raspberry Pi, ODroid, Pine64, etc) with a aarch64 architecture.

I cannot use the Python wheel. I need the C library to bind to a different language.

Will this change the current api? How?

No.

Who will benefit with this feature?

Anyone using a SBC with a aarch64 OS.

[eduardofv]

Haven't tried this myself, but you can find here how to install using pip directly on the Raspberry Pi

[marianopeck]

That would only work for installing the Python wheel. I need the C library to bind via FFI to other languages (like Go, Rust, etc)

[freedomtan]

Not sure about 1.13.1, For 1.14 or master branch, Something like

bazel --host_jvm_args=-Xms128m --host_jvm_args=-Xmx2048m \
build --config opt --local_resources 1024,1,1 \
tensorflow/tools/lib_package:libtensorflow

should just work. I think I upstreamed necessary patches for

bazel --host_jvm_args=-Xms128m --host_jvm_args=-Xmx2048m \
build --config opt --local_resources 1024,1,1 \
tensorflow/tools/pip_package:build_pip_package

Raspbian 32-bit is a bit complicated, because for RPI 3, an AAarch64 platform, it runs aarch32 (armv7-a) kernel, armv6 user-level binaries, and compilers/toolchains configured to armv6.

[marianopeck]

Hi @freedomtan
Thanks for your response. But there is something I am not sure I understand. The link I pasted above (in my original post) is a way for cross compiling for Raspberry Pi. Doing something as simple as:

      tensorflow/tools/ci_build/ci_build.sh PI \
      tensorflow/tools/ci_build/pi/build_raspberry_pi.sh

If you see here you can see all the magic. Cross compiling is much easier and faster than compiling on the Pi.

I have many images running 64 bits OS on a Pi 3 and 4 (Armiban, Ubuntu Server 18.04, etc)... In addition, an aarch64 build would also help other similar SBC like Pine64, Odriod etc..

What I was proposing is a similar build_raspberry_pi.sh but that would allow me to cross-compile for aarch64.

Thoughts?

[freedomtan]

Yes, cross-compiling usually is much faster, esp. for a fresh build. Easier, I don't think so. As I said, the environments before RPi 4 is quite complex.

[marianopeck]

Thanks @freedomtan for all your help.
I finally took the time to write down everything I found during my attempt to get TensorFlow C library compiled for Raspberry Pi. In that tutorial, I point back to this issue in case any progress is done.
Thank you

[lgeiger]

I added an AArch64 toolchain to bazel in #38399 which should make cross-compiling a lot easier. It would be great if the PR could get a review.

[terryheo]

There are commands to build Python PIP wheel for aarch64.
https://github.com/tensorflow/tensorflow/tree/master/tensorflow/lite/tools/pip_package

[google-ml-butler]

Are you satisfied with the resolution of your issue?
Yes
No

[terryheo]

Oh we need a guide to build full Tensorflow package. Let me check it.

[terryheo]

You can build TF Python wheel for aarch64.
https://www.tensorflow.org/install/source_rpi#python-3.8-64bit

[google-ml-butler]

Are you satisfied with the resolution of your issue?
Yes
No

[Yasin40]

Hi @freedomtan
Thanks for your response. But there is something I am not sure I understand. The link I pasted above (in my original post) is a way for cross compiling for Raspberry Pi. Doing something as simple as:

      tensorflow/tools/ci_build/ci_build.sh PI \
      tensorflow/tools/ci_build/pi/build_raspberry_pi.sh

If you see here you can see all the magic. Cross compiling is much easier and faster than compiling on the Pi.

I have many images running 64 bits OS on a Pi 3 and 4 (Armiban, Ubuntu Server 18.04, etc)... In addition, an aarch64 build would also help other similar SBC like Pine64, Odriod etc..

What I was proposing is a similar build_raspberry_pi.sh but that would allow me to cross-compile for aarch64.

Thoughts?

How can i cross compile TF for ODROID? This script work for odroid xu4?