Torch4Pizero

compiling the pytorch neural network backend for pizerow and bananapim2zero

This is not perfect. It is notes I made while figuring out how to get it going. there are typos, but I am able to follow this as a general guide and end up with an installable wheel for the pizerow.

I tried building on an actual pizeroW, but i think the memory requirements are too much. Instead I build it in a Docker container, emulating a 10-core 3.6 Ghz pizero. It takes about 5 hours to build.

First release is prebuilt wheels for python 3.9 that work on the 2022 and 2023 raspiOS bulids with kernels 5.15.84 and 6.1.21 so far.

Second release is for python 3.11 on RaspiOS based on Debian 12 "Bookworm"

Information below was the first version of the build script. 01-run-chroot.sh has a lot of bug fixes compared to the text below.

dd if=/dev/zero of=/swapfile1 bs=1024 count=3144000 chown root:root /swapfile1 chmod 0600 /swapfile1 mkswap /swapfile1 swapon /swapfile1

nano /etc/fstab

add following line to end of fstab

/swapfile1 none swap sw 0 0

################################ #!/usr/bin/env bash

cat > /tmp/dependencies << EOF libopenblas-dev cmake clang python3-distutils python3-dev python3-pip python3-protobuf python3-numpy python3-cffi python3-wheel python3-pillow python3-yaml python3-setuptools libprotobuf-dev EOF

sudo apt -q update for pkg in $(cat /tmp/dependencies) do sudo apt install -y $pkg done

#####################

git clone --depth=1 https://github.com/pytorch/pytorch --recursive && cd pytorch pip3 install -r requirements.txt

export USE_CUDA=0 export USE_DISTRIBUTED=0 export USE_MKLDNN=0 export BUILD_TEST=0 export BUILD_BINARY=0 export MAX_JOBS=1 export CC=clang

if [ $(uname -m} = "armv6l" ]; then export USE_NNPACK=0 export USE_QNNPACK=0 export USE_PYTORCH_QNNPACK=0 export USE_XNNPACK=0 export USE_NUMA=0 export USE_SYSTEM_CPUINFO=ON export USE_SYSTEM_SLEEF=ON export BUILD_CUSTOM_PROTOBUF=OFF

#### dependencies from armv6 build - some duplicates from above
apt install systemd passwd vim-minimal \
	libopenblas-dev libblas-dev m4 cmake cython3 python3-devel python3-yaml \
	python3-pil python3-setuptools python3-numpy python3-cffi python3-wheel \
	gcc-c++ tar gcc git make tmux

apt install libprotobuf-dev python3-protobuf
apt install libcpuinfo-dev

# patch /usr/include/cpuinfo.h for a missing check - GROSS, but whatever
sudo patch /usr/include/cpuinfo.h <<EOP

--- /tmp/cpuinfo.h 2023-07-09 11:36:13.993161372 -0700 +++ cpuinfo.h 2023-07-09 11:35:47.923343576 -0700 @@ -1468,6 +1468,11 @@ extern struct cpuinfo_arm_isa cpuinfo_isa; #endif

+/* needed for pytorch build */ +static inline bool cpuinfo_has_arm_bf16(void) {

• return false; +}

static inline bool cpuinfo_has_arm_thumb(void) { #if CPUINFO_ARCH_ARM return cpuinfo_isa.thumb; EOP

fi # if $(uname -m) = "armv6l"

time python3 setup.py bdist_wheel

torchvision

cd .. git clone --depth=1 https://github.com/pytorch/vision && cd vision

time python3 setup.py bdist_wheel

real 85m11.918s

#user 70m1.210s #sys 6m16.943s sudo python3 setup.py install