FPGA: Added workflow for PM5 fpga build.

.github/workflows/fpga-pm5.yml

@@ -0,0 +1,87 @@
+name: FPGA PM5 Build
+
+on:
+  push:
+    paths:
+      - 'fpga/**'
+      - '.github/workflows/fpga-pm5.yml'
+  pull_request:
+    paths:
+      - 'fpga/**'
+      - '.github/workflows/fpga-pm5.yml'
+  workflow_dispatch:
+
+env:
+  # oss-cad-suite is released daily; bump the date to move to a newer one.
+  OSS_CAD_SUITE_VERSION: '2026-10-11'
+
+permissions:
+  contents: read
+
+jobs:
+  pm5:
+    name: Build PM5 bitstream
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Install oss-cad-suite
+        run: |
+          set -euo pipefail
+          url="https://github.com/YosysHQ/oss-cad-suite-build/releases/download/${OSS_CAD_SUITE_VERSION}/oss-cad-suite-linux-x64-${OSS_CAD_SUITE_VERSION//-/}.tgz"
+          echo "Fetching $url"
+          curl -sSL "$url" | tar -xz -C "$RUNNER_TEMP"
+          # the makefile puts the suite's bin/, lib/ and bundled python3 in
+          # front of PATH itself, so nothing else needs to be exported
+          echo "OSS_CAD_SUITE=$RUNNER_TEMP/oss-cad-suite" >> "$GITHUB_ENV"
+
+      - name: Show the toolchain
+        run: |
+          set -euo pipefail
+          # the same resolution the build uses, then the versions for the log
+          make -C fpga -f proxmark5_fpga.mk check-tools
+          set +u
+          source "$OSS_CAD_SUITE/environment"
+          set -u
+          yosys -V
+          nextpnr-himbaechel --version
+          python3 -c "import apycula; print('apycula:', apycula.__file__)"
+
+      # Place and route fails the job on a timing violation, so this does not
+      # only prove the design still elaborates.
+      - name: Build the PM5 bitstream
+        run: make -C fpga pm5
+
+      - name: Check the bitstream
+        run: |
+          set -euo pipefail
+          bin_size=$(stat -c%s fpga/fpga_pm5.bin)
+          fs_size=$(stat -c%s fpga/fpga_pm5.fs)
+          echo "fpga_pm5.bin ${bin_size} bytes"
+          echo "fpga_pm5.fs  ${fs_size} bytes"
+          # the .bin is the bitstream the ARM JTAG loader shifts out, the .fs is
+          # its ASCII form: 8 characters plus a newline per byte
+          test "$bin_size" -gt 100000
+          test "$fs_size" -gt $((bin_size * 6))
+          test "$fs_size" -lt $((bin_size * 10))
+
+      # A rebuild from scratch has to produce the same bytes; the tools carry no
+      # timestamp, so a difference means something started leaking one in, and
+      # a released bitstream could no longer be checked against the sources.
+      - name: Check the build is reproducible
+        run: |
+          set -euo pipefail
+          md5sum fpga/fpga_pm5.fs fpga/fpga_pm5.bin > "$RUNNER_TEMP/bitstream.md5"
+          make -C fpga -f proxmark5_fpga.mk clean
+          make -C fpga pm5
+          md5sum -c "$RUNNER_TEMP/bitstream.md5"
+
+      - name: Upload the bitstream
+        uses: actions/upload-artifact@v6
+        with:
+          name: fpga-pm5-bitstream
+          path: |
+            fpga/fpga_pm5.fs
+            fpga/fpga_pm5.bin
+          if-no-files-found: error

fpga/proxmark5_fpga.mk

@@ -43,9 +43,12 @@ PM5_OUT  = $(PREFIX)build_$(PM5_NAME)
 
 # The oss-cad-suite launchers need their root, and both bin/ and lib/ on PATH
 # (lib/ carries the shared libraries), otherwise they exit without a message.
+# The suite bundles its own python, named per platform. With OSS_CAD_SUITE
+# unset everything comes from PATH instead, which is what sourcing the suite's
+# environment script gives you.
 ifneq ($(OSS_CAD_SUITE),)
-OC_ENV    = YOSYSHQ_ROOT="$(OSS_CAD_SUITE)/" PATH="$(OSS_CAD_SUITE)/bin:$(OSS_CAD_SUITE)/lib:$$PATH" PYTHON_EXECUTABLE="$(OSS_CAD_SUITE)/lib/python3.exe"
-OC_PYTHON = $(OSS_CAD_SUITE)/lib/python3.exe
+OC_PYTHON = $(firstword $(wildcard $(OSS_CAD_SUITE)/lib/python3.exe $(OSS_CAD_SUITE)/py3bin/python3 $(OSS_CAD_SUITE)/lib/python3 $(OSS_CAD_SUITE)/bin/python3) python3)
+OC_ENV    = YOSYSHQ_ROOT="$(OSS_CAD_SUITE)/" PATH="$(OSS_CAD_SUITE)/bin:$(OSS_CAD_SUITE)/lib:$$PATH" LD_LIBRARY_PATH="$(OSS_CAD_SUITE)/lib:$$LD_LIBRARY_PATH" PYTHON_EXECUTABLE="$(OC_PYTHON)"
 else
 OC_ENV    =
 OC_PYTHON = python3