feat: precheck (#30)

perform DRC checks on GDS files submitted to Tiny Tapeout

.github/workflows/test-precheck.yaml

@@ -0,0 +1,48 @@
+name: Precheck Tests
+
+on:
+  push:
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  test-precheck:
+    runs-on: ubuntu-latest
+    env:
+      PDK_ROOT: /home/runner/pdk
+      PDK_VERSION: dd7771c384ed36b91a25e9f8b314355fc26561be
+
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.11'
+          cache: 'pip'
+
+      - name: Install dependencies
+        working-directory: precheck
+        run: pip install -r requirements.txt
+
+      - name: Install Sky130 PDK
+        uses: TinyTapeout/volare-action@v1
+        with:
+          pdk_name: sky130
+          pdk_version: ${{ env.PDK_VERSION }}
+          pdk_root: ${{ env.PDK_ROOT }}
+
+      - name: Install Nix
+        uses: rikhuijzer/cache-install@v1.1.2
+        with:
+          key: nix-${{ hashFiles('precheck/default.nix') }}
+          nix_file: 'precheck/default.nix'
+
+      - name: Build Nix packages
+        working-directory: precheck
+        run: nix-build
+
+      - name: Run tests
+        working-directory: precheck
+        run: nix-shell --run "pytest"

precheck/.gitignore

@@ -0,0 +1,2 @@
+__pycache__
+.pytest_cache

precheck/default.nix

@@ -0,0 +1,11 @@
+{ pkgs ? import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/8f7a6554c058bfdae00f4fb36f5cd52838f410e7.tar.gz")
+    { }
+,
+}:
+
+pkgs.mkShell {
+  buildInputs = [
+    pkgs.klayout
+    pkgs.magic-vlsi
+  ];
+}

precheck/klayout_tools.py

@@ -0,0 +1,42 @@
+import xml.etree.ElementTree as ET
+from typing import Dict
+
+
+class LayerInfo:
+    def __init__(self, name: str, source: str, layer: int, data_type: int):
+        self.name = name
+        self.source = source
+        self.layer = layer
+        self.data_type = data_type
+
+    def __repr__(self):
+        return f"LayerInfo(name={self.name}, source={self.source}, layer={self.layer}, data_type={self.data_type})"
+
+
+def parse_lyp_layers(lyp_file: str):
+    with open(lyp_file) as f:
+        xml_content = f.read()
+    root = ET.fromstring(xml_content)
+
+    layers_dict: Dict[str, LayerInfo] = {}
+
+    for properties in root.findall("properties"):
+        name = properties.find("name")
+        source = properties.find("source")
+        valid = properties.find("valid")
+
+        if valid is not None and valid.text == "false":
+            continue
+
+        if name is not None and source is not None:
+            name_key = name.text.split("-")[0].strip()
+            layer, data_type = source.text.split("@")[0].split("/")
+            # Add the 'source' text as the value in the dictionary
+            layers_dict[name_key] = LayerInfo(
+                name=name.text,
+                source=source.text,
+                layer=int(layer),
+                data_type=int(data_type),
+            )
+
+    return layers_dict

precheck/magic_drc.tcl

@@ -0,0 +1,77 @@
+# SPDX-FileCopyrightText: 2020 Efabless Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# SPDX-License-Identifier: Apache-2.0
+
+
+set GDS_UT_PATH [lindex $argv 6]
+set DESIGN_NAME [lindex $argv 7]
+set PDK_PATH [lindex $argv 8]
+set DRC_REPORT [lindex $argv 9]
+set DRC_MAG [lindex $argv 10]
+
+gds read $GDS_UT_PATH
+
+set fout [open $DRC_REPORT w]
+set oscale [cif scale out]
+set cell_name $DESIGN_NAME
+magic::suspendall
+puts stdout "\[INFO\]: Loading $cell_name\n"
+flush stdout
+load $cell_name
+select top cell
+expand
+drc euclidean on
+drc style drc(full)
+drc check
+set drc_result [drc listall why]
+
+
+set count 0
+puts $fout "$cell_name"
+puts $fout "----------------------------------------"
+foreach {errtype coordlist} $drc_result {
+	puts $fout $errtype
+	puts $fout "----------------------------------------"
+	foreach coord $coordlist {
+	    set bllx [expr {$oscale * [lindex $coord 0]}]
+	    set blly [expr {$oscale * [lindex $coord 1]}]
+	    set burx [expr {$oscale * [lindex $coord 2]}]
+	    set bury [expr {$oscale * [lindex $coord 3]}]
+	    set coords [format " %.3f %.3f %.3f %.3f" $bllx $blly $burx $bury]
+	    puts $fout "$coords"
+	    set count [expr {$count + 1} ]
+	}
+	puts $fout "----------------------------------------"
+}
+
+puts $fout "\[INFO\]: COUNT: $count"
+puts $fout "\[INFO\]: Should be divided by 3 or 4"
+
+puts $fout ""
+close $fout
+
+puts stdout "\[INFO\]: DRC Checking DONE ($DRC_REPORT)"
+flush stdout
+
+if {$count > 0} {
+    puts stderr "\[ERROR\]: $count DRC errors found"
+    puts stdout "\[INFO\]: Saving mag view with DRC errors($DRC_MAG)"
+    # WARNING: changes the name of the cell; keep as last step
+    save $DRC_MAG
+    puts stdout "\[INFO\]: Saved"
+    flush stdout
+    exit -1
+} else {
+    exit 0
+}

precheck/precheck.py

@@ -0,0 +1,121 @@
+#!/usr/bin/env python3
+import argparse
+import logging
+import os
+import subprocess
+
+import klayout.db as pya
+import klayout.rdb as rdb
+from klayout_tools import parse_lyp_layers
+
+PDK_ROOT = os.getenv("PDK_ROOT")
+PDK_NAME = os.getenv("PDK_NAME") or "sky130A"
+LYP_FILE = f"{PDK_ROOT}/{PDK_NAME}/libs.tech/klayout/tech/{PDK_NAME}.lyp"
+REPORTS_PATH = os.path.join(os.path.dirname(os.path.realpath(__file__)), "reports")
+
+
+def magic_drc(gds: str, toplevel: str):
+    logging.info(f"Running magic DRC on {gds} (module={toplevel})")
+
+    magic = subprocess.run(
+        [
+            "magic",
+            "-noconsole",
+            "-dnull",
+            "-rcfile",
+            f"{PDK_ROOT}/{PDK_NAME}/libs.tech/magic/{PDK_NAME}.magicrc",
+            "magic_drc.tcl",
+            gds,
+            toplevel,
+            PDK_ROOT,
+            f"{REPORTS_PATH}/magic_drc.txt",
+            f"{REPORTS_PATH}/magic_drc.mag",
+        ],
+    )
+
+    if magic.returncode != 0:
+        logging.error("Magic DRC failed")
+        return False
+
+    return True
+
+
+def klayout_drc(gds: str, check: str):
+    logging.info(f"Running klayout {check} on {gds}")
+    report_file = f"{REPORTS_PATH}/drc_{check}.xml"
+    klayout = subprocess.run(
+        [
+            "klayout",
+            "-b",
+            "-r",
+            f"tech-files/{PDK_NAME}_mr.drc",
+            "-rd",
+            f"{check}=true",
+            "-rd",
+            f"input={gds}",
+            "-rd",
+            f"report={report_file}",
+        ],
+    )
+    if klayout.returncode != 0:
+        logging.error(f"Klayout {check} failed")
+        return False
+
+    report = rdb.ReportDatabase().load(report_file)
+
+    if report.num_items() > 0:
+        logging.error(
+            f"Klayout {check} failed with {report.num_items()} DRC violations"
+        )
+        return False
+
+    return True
+
+
+def klayout_checks(gds: str):
+    layout = pya.Layout()
+    layout.read(gds)
+    layers = parse_lyp_layers(LYP_FILE)
+
+    logging.info("Running forbidden layer check...")
+    forbidden_layers = [
+        "met5.drawing",
+        "met5.pin",
+        "met5.label",
+    ]
+
+    had_error = False
+    for layer in forbidden_layers:
+        layer_info = layers[layer]
+        logging.info(f"* Checking {layer_info.name}")
+        layer_index = layout.find_layer(layer_info.layer, layer_info.data_type)
+        if layer_index is not None:
+            logging.error(f"Forbidden layer {layer} found in {gds}")
+            had_error = True
+
+    if had_error:
+        logging.error("Klayout checks failed")
+    return not had_error
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--gds", required=True)
+    parser.add_argument("--toplevel", required=True)
+    args = parser.parse_args()
+    logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s")
+    logging.info(f"PDK_ROOT: {PDK_ROOT}")
+
+    assert magic_drc(args.gds, args.toplevel)
+
+    assert klayout_drc(args.gds, "feol")
+    assert klayout_drc(args.gds, "beol")
+    assert klayout_drc(args.gds, "offgrid")
+
+    assert klayout_checks(args.gds)
+
+    logging.info(f"Precheck passed for {args.gds}! 🎉")
+
+
+if __name__ == "__main__":
+    main()

precheck/reports/.gitignore

@@ -0,0 +1,5 @@
+magic_drc.mag
+magic_drc.txt
+drc_feol.xml
+drc_beol.xml
+drc_offgrid.xml

precheck/requirements.txt

@@ -0,0 +1,2 @@
+klayout==0.28.12
+pytest==7.4.3

precheck/tech-files/README.txt

@@ -0,0 +1 @@
+sky130A_mr.drc from https://github.com/efabless/mpw_precheck revision 4efb33553ee6c2acdb0fa9a6a5f87af099f5c1d5