Unsupported Architecture Issue while cross-compiling on linux

[aarifzafar1]

Describe the bug
I am trying to build onnx-genai library(shared object) by cross compiling for a linux based custom architecture. I have made the same for onnxruntime and I am able to build, while facing below issue while building onnx-genai:

-- Fetch json
-- Tokenizer needed.
-- math lib 'libm' not found; floating point support disabled
CMake Error at cmake/global_variables.cmake:153 (message):
Unsupported architecture. CMAKE_SYSTEM_PROCESSOR:
Call Stack (most recent call first):
CMakeLists.txt:37 (include)

-- Configuring incomplete, errors occurred!
Traceback (most recent call last):
File "/home/test/onnxruntime/onnxruntime-genai/build.py", line 656, in
update(arguments, environment)
File "/home/test/onnxruntime/onnxruntime-genai/build.py", line 574, in update
util.run(command, env=env)
File "/home/test/onnxruntime/onnxruntime-genai/tools/python/util/run.py", line 56, in run
completed_process = subprocess.run(
File "/usr/lib/python3.8/subprocess.py", line 516, in run
raise CalledProcessError(retcode, process.args,
subprocess.CalledProcessError: Command '['/usr/local/bin/cmake', '-G', 'Unix Makefiles', '-DCMAKE_BUILD_TYPE=MinSizeRel', '-S', '/home/test/onnxruntime/onnxruntime-genai', '-B', '/home/test/onnxruntime/onnxruntime-genai/build/basic/MinSizeRel', '-DCMAKE_POSITION_INDEPENDENT_CODE=ON', '-DUSE_CUDA=OFF', '-DUSE_ROCM=OFF', '-DUSE_DML=OFF', '-DENABLE_JAVA=OFF', '-DBUILD_WHEEL=ON', '-DCMAKE_TOOLCHAIN_FILE=/home/test/custom-toolchains/toolchains/aarch64-custom-linux-musl/tools.cmake', '-DCMAKE_POSITION_INDEPENDENT_CODE=ON']' returned non-zero exit status 1.

The command used to build is below:

./build.sh --build_dir build/basic --config MinSizeRel --parallel --cmake_extra_defines CMAKE_TOOLCHAIN_FILE="/test/custom-toolchains/toolchains/aarch64-custom-linux-musl/tools.cmake" CMAKE_POSITION_INDEPENDENT_CODE=ON --skip_tests

The debugging suggest the below line in build.py causing the error:
build.py", line 574, in update
util.run(command, env=env)

Is the linux environment not supported for cross compiling or is it some other issue?

[snnn]

Please set CMAKE_SYSTEM_PROCESSOR in the toolchain cmake file

[aarifzafar1]

Dear @snnn
Thank you for replying the primary fix for the issue.
I have set the CMAKE_SYSTEM_PROCESSOR in toolchain but it is not reflecting while building. Although I fixed the issue with some hardcoding in global_variables.cmake file.
But I have ran into some other issue.
The issue is as below:

[ 89%] Building CXX object CMakeFiles/onnxruntime-genai.dir/src/webgpu/interface.cpp.o
In file included from /home/test/onnxruntime-genai/onnxruntime-genai/src/models/captured_graph_pool.cpp:1:
In file included from /home/test/onnxruntime-genai/onnxruntime-genai/src/models/captured_graph_pool.h:7:
In file included from /home/test/onnxruntime-genai/onnxruntime-genai/src/models/static_buffer.h:6:
/home/test/onnxruntime-genai/onnxruntime-genai/src/models/onnxruntime_api.h:156:35: error: use of undeclared identifier 'RTLD_DI_ORIGIN'
156 | dlinfo((void*)ort_lib_handle, RTLD_DI_ORIGIN, &pathname);

On debugging, I have found that RTLD_DI_ORIGIN is undefined incase we are compiling the source code for Android or Apple. But I am buildng right now with custom toolchain and build command used is below, so not sure the cause of the error:

Build Command:
./build.sh --build_dir build/basic --config MinSizeRel --parallel --cmake_extra_defines CMAKE_TOOLCHAIN_FILE="/test/custom-toolchains/toolchains/aarch64-custom-linux-musl/tools.cmake" CMAKE_POSITION_INDEPENDENT_CODE=ON --skip_tests

[snnn]

You are building it for musl? We never tested the config. I believe the error was because the libc doesn't have the RTLD_DI_ORIGIN symbol. I think we should add a check to this project's top level CMakeLists.txt to check if the symbol exists, then add #ifdef to the code that caused the error. Then the build will pass, but, certainly the functionalities that rely on the code path wouldn't work. It's not big deal I think, if you only use the default CPU execution provider.