added detailed instructions for xtensa cmake and devserver setup (#5398)

Summary:
Pull Request resolved: #5398

Recently change in cadence added new internal dependencies which caused confusion in building the hifi binaries. Added detailed intrustiones in a sample bash script to build with xtensa toolchain.

Also based on internal development, added instructions to setup cmake/pip on internal developement servers.

Reviewed By: hsharma35, mcremon-meta

Differential Revision: D62768143

fbshipit-source-id: 9d531e01034852c76a2870e96274d24c07e7f9a7

Author: zonglinpeng

backends/cadence/build_cadence_xtensa.sh

@@ -0,0 +1,88 @@
+#!/bin/bash
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+
+set -euo pipefail
+
+unset CMAKE_PREFIX_PATH
+git submodule sync
+git submodule update --init
+./install_requirements.sh
+
+rm -rf cmake-out
+
+STEPWISE_BUILD=false
+
+if $STEPWISE_BUILD; then
+    echo "Building ExecuTorch"
+    cmake -DCMAKE_INSTALL_PREFIX=cmake-out \
+        -DCMAKE_TOOLCHAIN_FILE=./backends/cadence/cadence.cmake  \
+        -DCMAKE_BUILD_TYPE=Release \
+        -DEXECUTORCH_ENABLE_EVENT_TRACER=OFF \
+        -DEXECUTORCH_BUILD_EXTENSION_RUNNER_UTIL=ON \
+        -DEXECUTORCH_BUILD_EXECUTOR_RUNNER=OFF \
+        -DEXECUTORCH_BUILD_PTHREADPOOL=OFF \
+        -DEXECUTORCH_BUILD_CPUINFO=OFF \
+        -DEXECUTORCH_ENABLE_LOGGING=ON \
+        -DEXECUTORCH_USE_DL=OFF \
+        -DEXECUTORCH_BUILD_CADENCE=OFF \
+        -DFLATC_EXECUTABLE="$(which flatc)" \
+        -Bcmake-out .
+
+    echo "Building any Cadence-specific binaries on top"
+    cmake -DBUCK2="$BUCK" \
+        -DCMAKE_TOOLCHAIN_FILE=./backends/cadence/cadence.cmake \
+        -DCMAKE_INSTALL_PREFIX=cmake-out \
+        -DCMAKE_BUILD_TYPE=Release \
+        -DEXECUTORCH_BUILD_HOST_TARGETS=ON \
+        -DEXECUTORCH_BUILD_EXECUTOR_RUNNER=ON \
+        -DEXECUTORCH_BUILD_PTHREADPOOL=OFF \
+        -DEXECUTORCH_BUILD_CADENCE=ON \
+        -DFLATC_EXECUTABLE="$(which flatc)" \
+        -DEXECUTORCH_ENABLE_LOGGING=ON \
+        -DEXECUTORCH_ENABLE_PROGRAM_VERIFICATION=ON \
+        -DEXECUTORCH_USE_DL=OFF \
+        -DBUILD_EXECUTORCH_PORTABLE_OPS=ON \
+        -DEXECUTORCH_BUILD_KERNELS_CUSTOM=OFF \
+        -DPYTHON_EXECUTABLE=python3 \
+        -DEXECUTORCH_NNLIB_OPT=ON \
+        -DEXECUTORCH_BUILD_GFLAGS=ON \
+        -DHAVE_FNMATCH_H=OFF \
+        -Bcmake-out/backends/cadence \
+        backends/cadence
+    cmake --build cmake-out/backends/cadence  -j16
+else
+    echo "Building Cadence toolchain with ExecuTorch packages"
+    cmake_prefix_path="${PWD}/cmake-out/lib/cmake/ExecuTorch;${PWD}/cmake-out/third-party/gflags"
+    cmake -DBUCK2="$BUCK" \
+        -DCMAKE_PREFIX_PATH="${cmake_prefix_path}" \
+        -DCMAKE_TOOLCHAIN_FILE=./backends/cadence/cadence.cmake \
+        -DCMAKE_INSTALL_PREFIX=cmake-out \
+        -DCMAKE_BUILD_TYPE=Release \
+        -DEXECUTORCH_BUILD_HOST_TARGETS=ON \
+        -DEXECUTORCH_BUILD_EXECUTOR_RUNNER=ON \
+        -DEXECUTORCH_BUILD_PTHREADPOOL=OFF \
+        -DEXECUTORCH_BUILD_CADENCE=OFF \
+        -DFLATC_EXECUTABLE="$(which flatc)" \
+        -DEXECUTORCH_ENABLE_LOGGING=ON \
+        -DEXECUTORCH_ENABLE_PROGRAM_VERIFICATION=ON \
+        -DEXECUTORCH_USE_DL=OFF \
+        -DBUILD_EXECUTORCH_PORTABLE_OPS=ON \
+        -DEXECUTORCH_BUILD_KERNELS_CUSTOM=OFF \
+        -DPYTHON_EXECUTABLE=python3 \
+        -DEXECUTORCH_NNLIB_OPT=ON \
+        -DEXECUTORCH_BUILD_GFLAGS=ON \
+        -DHAVE_FNMATCH_H=OFF \
+        -DEXECUTORCH_ENABLE_EVENT_TRACER=OFF \
+        -DEXECUTORCH_BUILD_EXTENSION_RUNNER_UTIL=ON \
+        -DEXECUTORCH_BUILD_CPUINFO=OFF \
+        -Bcmake-out
+    cmake --build cmake-out --target install --config Release -j16
+fi
+
+echo "Run simple model to verify cmake build"
+python3 -m examples.portable.scripts.export --model_name="add"
+xt-run --turbo cmake-out/executor_runner  --model_path=add.pte