riseproject-dev · luhenry · Sep 21, 2026 · Sep 21, 2026
diff --git a/.github/workflows/build-usd-core.yml b/.github/workflows/build-usd-core.yml
@@ -0,0 +1,194 @@
+# SPDX-FileCopyrightText: 2026 The RISE Project
+# SPDX-License-Identifier: MIT
+---
+# Mirrors the Linux job of upstream's .github/workflows/pypi.yml: build_usd.py with
+# imaging/MaterialX/examples/tutorials off, then build_scripts/pypi/{setup.py,
+# updatePluginfos.py}, narrowed to riscv64.
+name: Build usd-core wheels (riscv64)
+
+on:
+  workflow_dispatch:
+    inputs:
+      version:
+        description: 'Version glob to (re)build; empty builds every version of docs/packages/usd-core.yaml not released yet'
+        required: false
+        default: ''
+  pull_request:
+    branches: [main]
+    paths:
+      - '.github/workflows/build-usd-core.yml'
+      - 'docs/packages/usd-core.yaml'
+      - 'patches/usd-core/**'
+  push:
+    branches: [main]
+    paths:
+      - '.github/workflows/build-usd-core.yml'
+      - 'docs/packages/usd-core.yaml'
+      - 'patches/usd-core/**'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+env:
+  MANYLINUX_RISCV64_IMAGE: quay.io/pypa/manylinux_2_39_riscv64
+
+jobs:
+  setup:
+    uses: $/.github/workflows/_setup.yml
+    with:
+      package: usd-core
+      version: ${{ inputs.version }}
+
+  build_wheels:
+    needs: [setup]
+    if: needs.setup.outputs.versions != '[]'
+    name: Build usd-core ${{ matrix.version }} ${{ matrix.python }}-manylinux_riscv64
+    runs-on: ubuntu-24.04-riscv
+    timeout-minutes: 1440
+    strategy:
+      fail-fast: false
+      matrix:
+        version: ${{ fromJSON(needs.setup.outputs.versions) }}
+        # Upstream publishes cp39-cp314 and no free-threaded wheel; the
+        # pxr_boost::python bindings never declare Py_mod_gil, so a cp314t wheel
+        # would only re-enable the GIL.
+        python: ["cp312", "cp313", "cp314"]
+
+    env:
+      USD_CORE_VERSION: ${{ matrix.version }}
+
+    steps:
+      - name: Resolve the OpenUSD release tag
+        id: tag
+        run: |
+          set -euo pipefail
+          printf 'tag=v%s\n' \
+            "$(awk -F. '{printf "%s.%02d", $1, $2}' <<<"${USD_CORE_VERSION}")" >> "$GITHUB_OUTPUT"
+
+      - name: Checkout OpenUSD ${{ steps.tag.outputs.tag }}
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          repository: PixarAnimationStudios/OpenUSD
+          ref: ${{ steps.tag.outputs.tag }}
+          persist-credentials: false
+
+      - name: Checkout python-wheels
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          path: python-wheels
+          fetch-depth: 1
+          persist-credentials: false
+
+      - name: Patch OpenUSD
+        run: git apply python-wheels/patches/usd-core/${{ env.USD_CORE_VERSION }}/00*.patch
+
+      - name: Pull manylinux_riscv64 image
+        run: docker pull "${MANYLINUX_RISCV64_IMAGE}"
+
+      - name: Build USD and the wheel
+        run: |
+          mkdir -p dist
+          docker run -i --rm \
+            -v "${GITHUB_WORKSPACE}:/work" \
+            -w /work \
+            -e PYTHON_TAG="${{ matrix.python }}" \
+            "${MANYLINUX_RISCV64_IMAGE}" bash -s <<'USD_BUILD_EOF'
+          #!/usr/bin/env bash
+          set -euxo pipefail
+
+          PY="/opt/python/${PYTHON_TAG}-${PYTHON_TAG}/bin/python"
+          "$PY" -m pip install setuptools wheel
+
+          # Upstream's own pypi.yml hack: the manylinux image ships no libpython
+          # (PEP 513), and FindPython's Development component refuses to configure
+          # without the file even though PXR_PY_UNDEFINED_DYNAMIC_LOOKUP means USD
+          # never links against it.
+          "$PY" -c "import pathlib,sysconfig; pathlib.Path(sysconfig.get_config_var('LIBDIR'), sysconfig.get_config_var('LDLIBRARY')).touch()"
+
+          "$PY" build_scripts/build_usd.py --build-monolithic \
+            --build-args USD,"-DPXR_PY_UNDEFINED_DYNAMIC_LOOKUP=ON -DPXR_BUILD_USD_TOOLS=OFF -DPXR_BUILD_EXEC=OFF -DPXR_INSTALL_LOCATION=../pxr/pluginfo -DPXR_PYTHON_INSTALL_DIR=lib/python" \
+            --no-materialx --no-imaging --no-examples --no-tutorials \
+            --build /work/gen/build --src /work/gen/src /work/inst -v
+
+          mkdir packaging
+          cp -R /work/inst ./packaging
+          cp build_scripts/pypi/package_files/* ./packaging
+          cp LICENSE.txt ./packaging
+          # auditwheel vendors the TBB shared library into the wheel, so its
+          # Apache-2.0 text has to travel with it; setuptools' default
+          # license_files glob picks LICENSE* up without a setup.py edit.
+          cp gen/src/oneTBB-*/LICENSE ./packaging/LICENSE.oneTBB.txt
+
+          cd packaging
+          "$PY" setup.py bdist_wheel --python-tag "${PYTHON_TAG}"
+          cd /work
+
+          PYTHONPATH=/work/packaging/pypi/lib/python \
+          LD_LIBRARY_PATH="/work/packaging/pypi/lib:${LD_LIBRARY_PATH:-}" \
+            auditwheel repair packaging/dist/*.whl
+
+          repaired="$(echo wheelhouse/*.whl)"
+          "$PY" build_scripts/pypi/updatePluginfos.py \
+            "${repaired}" "/work/dist/$(basename "${repaired}")"
+          ls -la /work/dist
+          USD_BUILD_EOF
+
+      - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a  # v7.0.1
+        with:
+          name: usd-core-${{ env.USD_CORE_VERSION }}-${{ matrix.python }}-manylinux_riscv64
+          path: dist/*.whl
+          if-no-files-found: error
+
+      - name: Test usd-core wheel
+        run: |
+          docker run -i --rm \
+            -v "${GITHUB_WORKSPACE}:/work" \
+            -w /work \
+            -e PYTHON_TAG="${{ matrix.python }}" \
+            "${MANYLINUX_RISCV64_IMAGE}" bash -s <<'USD_TEST_EOF'
+          #!/usr/bin/env bash
+          set -euxo pipefail
+
+          PY="/opt/python/${PYTHON_TAG}-${PYTHON_TAG}/bin/python"
+          "$PY" -m pip install pytest
+          "$PY" -m pip install --no-index --find-links=/work/dist usd-core
+
+          # /work/pxr is the checkout's C++ source tree and would shadow the
+          # installed package as a namespace package, so run from elsewhere and
+          # prove which pxr was imported.
+          cd /tmp
+          "$PY" -c "
+          import pathlib, pxr
+          p = pathlib.Path(pxr.__file__)
+          print(p)
+          assert 'site-packages' in p.parts
+          import importlib, pkgutil
+          mods = sorted(m.name for m in pkgutil.iter_modules(pxr.__path__))
+          for m in mods:
+              importlib.import_module('pxr.' + m)
+          print(len(mods), 'modules imported:', ' '.join(mods))
+          assert 'Usd' in mods and 'Sdf' in mods and 'UsdGeom' in mods
+          "
+          "$PY" -m pytest -v /work/build_scripts/pypi/test.py
+          USD_TEST_EOF
+
+  publish:
+    name: Publish usd-core ${{ matrix.version }}
+    needs: [setup, build_wheels]
+    if: needs.setup.outputs.versions != '[]'
+    strategy:
+      fail-fast: false
+      matrix:
+        version: ${{ fromJSON(needs.setup.outputs.versions) }}
+    permissions:
+      contents: write
+      pull-requests: write
+    uses: $/.github/workflows/_publish-wheel.yml
+    secrets:
+      app-private-key: ${{ secrets.RISEPROJECT_APP_PRIVATE_KEY }}
+    with:
+      artifact-pattern: usd-core-${{ matrix.version }}-*-manylinux_riscv64
diff --git a/docs/packages/usd-core.yaml b/docs/packages/usd-core.yaml
@@ -0,0 +1,6 @@
+package-name: usd-core
+source-code: https://github.com/PixarAnimationStudios/OpenUSD
+license: LicenseRef-TOST-1.0
+versions:
+- version: 26.8
+  patched: true
diff --git a/patches/usd-core/26.8/0001-Support-riscv64-in-pxr-base-arch.patch b/patches/usd-core/26.8/0001-Support-riscv64-in-pxr-base-arch.patch
@@ -0,0 +1,121 @@
+From e346d5ee838ae79333ed9e0f6242891c841ed1b8 Mon Sep 17 00:00:00 2001
+From: Ludovic Henry <git@ludovic.dev>
+Date: Mon, 21 Sep 2026 01:53:09 +0000
+Subject: [PATCH] Support riscv64 in pxr/base/arch
+
+pxr/base/arch/defines.h recognises only x86 and ARM, and its "Bits" block
+ends in #error "Unsupported architecture.  x86_64 or ARM64 required." - so
+every translation unit of USD fails on riscv64 before anything else is
+compiled. Two further sites are reached once that is fixed: arch/math.h
+guards ArchSign/ArchFloatToBitPattern/... on
+ARCH_CPU_INTEL || ARCH_CPU_ARM || ARCH_OS_WASM_VM and ends in #error Unknown
+system architecture (the code it guards is portable IEEE-754 bit twiddling,
+not x86 or ARM specific), and nonLockingLinux__execve() in
+arch/stackTrace.cpp has hand-written syscall asm for aarch64 and x86_64 with
+#error Unknown architecture in the #else.
+
+Add an ARCH_CPU_RISCV define for __riscv, admit __riscv_xlen == 64 to
+ARCH_BITS_64, let math.h's gate accept it, and give
+nonLockingLinux__execve() a riscv64 branch. The syscall branch mirrors the
+aarch64 one exactly: the Linux riscv64 ABI passes arguments in a0-a2, takes
+the syscall number in a7, uses the same generic __NR_execve == 221 as
+aarch64, and traps with ecall instead of svc. Everything else in arch is
+already portable: ARCH_SPIN_PAUSE() has a no-op #else, timing.h only reaches
+rdtsc behind PXR_ARCH_PREFER_TSC_TIMING and otherwise uses
+std::chrono::steady_clock, and the remaining #error branches in
+systemInfo.cpp/fileSystem.cpp/assumptions.cpp select on the OS, not the CPU.
+
+With this, the core (non-imaging) USD libraries and their Python bindings
+build and run on riscv64; pxr/base/gf's SIMD paths are already gated on
+__SSE2__/__ARM_NEON with scalar fallbacks, and the vendored
+double-conversion already lists __riscv.
+
+Upstream-Status: To upstream [not submitted from this automated port run; needs a pull request against PixarAnimationStudios/OpenUSD]
+---
+ pxr/base/arch/defines.h      |  7 +++++--
+ pxr/base/arch/math.h         |  1 +
+ pxr/base/arch/overview.dox   |  1 +
+ pxr/base/arch/stackTrace.cpp | 14 ++++++++++++++
+ 4 files changed, 21 insertions(+), 2 deletions(-)
+
+diff --git a/pxr/base/arch/defines.h b/pxr/base/arch/defines.h
+index b7ed634..58e860c 100644
+--- a/pxr/base/arch/defines.h
++++ b/pxr/base/arch/defines.h
+@@ -39,6 +39,8 @@
+ #elif defined(__arm__) || defined(__aarch64__) || defined(_M_ARM) || \
+     defined(_M_ARM64)
+ #define ARCH_CPU_ARM
++#elif defined(__riscv)
++#define ARCH_CPU_RISCV
+ #endif
+
+ //
+@@ -46,12 +48,13 @@
+ //
+
+ #if defined(__x86_64__) || defined(__aarch64__) || defined(_M_X64) || \
+-    defined(_M_ARM64) || defined(__wasm64__)
++    defined(_M_ARM64) || defined(__wasm64__) || \
++    (defined(__riscv) && __riscv_xlen == 64)
+ #define ARCH_BITS_64
+ #elif defined(__wasm32__)
+ #define ARCH_BITS_32
+ #else
+-#error "Unsupported architecture.  x86_64 or ARM64 required."
++#error "Unsupported architecture.  x86_64, ARM64 or RISC-V 64 required."
+ #endif
+
+ //
+diff --git a/pxr/base/arch/math.h b/pxr/base/arch/math.h
+index ccd53a6..8191023 100644
+--- a/pxr/base/arch/math.h
++++ b/pxr/base/arch/math.h
+@@ -30,6 +30,7 @@ PXR_NAMESPACE_OPEN_SCOPE
+ ///@{
+
+ #if defined (ARCH_CPU_INTEL) || defined (ARCH_CPU_ARM) ||  \
++    defined (ARCH_CPU_RISCV) || \
+     defined(ARCH_OS_WASM_VM) || defined (doxygen)
+
+ /// This is the smallest value e such that 1+e^2 == 1, using floats.
+diff --git a/pxr/base/arch/overview.dox b/pxr/base/arch/overview.dox
+index b8eaf9b..045375b 100644
+--- a/pxr/base/arch/overview.dox
++++ b/pxr/base/arch/overview.dox
+@@ -64,6 +64,7 @@ For processor:
+     <ul>
+     <li> ARCH_CPU_INTEL
+     <li> ARCH_CPU_ARM
++    <li> ARCH_CPU_RISCV
+     </ul>
+
+ For bits:
+diff --git a/pxr/base/arch/stackTrace.cpp b/pxr/base/arch/stackTrace.cpp
+index 384959e..6a90d38 100644
+--- a/pxr/base/arch/stackTrace.cpp
++++ b/pxr/base/arch/stackTrace.cpp
+@@ -878,6 +878,20 @@ nonLockingLinux__execve (const char *file,
+         );
+         result = __file_result;
+     }
++#elif defined (ARCH_CPU_RISCV) && defined(ARCH_BITS_64)
++    {
++        long __file_result asm ("a0") = (long)file;
++        char* const* __argv asm ("a1") = argv;
++        char* const* __envp asm ("a2") = envp;
++        long __num_execve asm ("a7") = 221;
++        __asm__ __volatile__ (
++            "ecall"
++            : "=r" (__file_result)
++            : "r"(__num_execve), "r" (__file_result), "r" (__argv), "r" (__envp)
++            : "memory"
++        );
++        result = __file_result;
++    }
+ #elif defined(ARCH_CPU_INTEL) && defined(ARCH_BITS_64)
+
+     /*
+-- 
+2.43.0
+