diff --git a/.gitmodules b/.gitmodules
index 5dded52..eca064e 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,6 @@
 [submodule "yosys"]
-	path = yosys
+	path = yowasp-yosys
 	url = https://github.com/YoWASP/yosys
+[submodule "churchroad"]
+	path = churchroad
+	url = https://github.com/uwsampl/churchroad
diff --git a/Dockerfile b/Dockerfile
index 0128d96..17a3204 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,2 +1,74 @@
 FROM ubuntu:24.04
 
+RUN apt-get update && apt-get install -y \
+  autoconf \
+  bison \
+  build-essential \
+  ccache \
+  clang \
+  curl \
+  flex \
+  git \
+  libc6 \
+  libc6-dev \
+  libtool \
+  python3 \
+  wget \
+  xz-utils
+
+# Download and build libffi-emscripten.
+WORKDIR /root
+RUN \
+  # Begin by installing emsdk.
+  mkdir emsdk \
+  && wget -qO- https://github.com/emscripten-core/emsdk/archive/176dec4875db4d74c2038d7e8af3395be38d222c.tar.gz | tar xz -C emsdk --strip-components=1 \
+  && cd emsdk \
+  && ./emsdk install latest \
+  && ./emsdk activate latest \
+  && . "/root/emsdk/emsdk_env.sh" \
+  && cd /root \
+  && mkdir libffi-emscripten \
+  && wget -qO- https://github.com/hoodmane/libffi-emscripten/archive/44cb3268c778b0894a37cddc4ee7c89189197f55.tar.gz | tar xz -C libffi-emscripten --strip-components=1 \
+  && cd libffi-emscripten \
+  && ./testsuite/emscripten/build.sh
+
+RUN apt install -y pkg-config npm tclsh
+
+WORKDIR /root
+ADD churchroad churchroad
+
+# Build yowasp-yosys. I don't love that we need to clone instead of downloading
+# a release tarball, but the release tarballs don't include the submodules. I
+# also tried using a submodule, but then it doesn't have the .git directory,
+# which it seems to depend on.
+WORKDIR /root
+ARG MAKE_JOBS=1
+RUN \
+  git clone --recursive https://github.com/YoWASP/yosys yowasp-yosys \
+  && cd yowasp-yosys \
+  && git checkout ca630ead0ca01c06c389176a163966edeb07f151 \
+  && git submodule update \
+  && . "/root/emsdk/emsdk_env.sh" \
+  # We need the Churchroad backend to be part of Yosys. I tried enabling plugins
+  # with wasm, but it was more effort than it was worth given that we could also
+  # just hack the backend into the Yosys source. The comented out lines are
+  # artifacts of me trying to get plugins to work.
+  #
+  # && sed -i 's/ENABLE_PLUGINS := 0/ENABLE_PLUGINS := 1/' build.sh \
+  # && sed -i 's$LINKFLAGS += -Wl,--strip-all$LINKFLAGS += -Wl,--strip-all,-L/root/libffi-emscripten/target/lib$' build.sh \
+  #
+  # Enable parallel build.
+  && sed -i 's$make -C yosys-build -f ../yosys-src/Makefile PRETTY=0 CXX="ccache clang"$make -j'${MAKE_JOBS}' -C yosys-build -f ../yosys-src/Makefile PRETTY=0 CXX="ccache clang"$' build.sh \
+  # Add Churchroad backend to Yosys.
+  && mkdir yosys-src/backends/churchroad \
+  && echo "OBJS += backends/churchroad/churchroad.o" >> yosys-src/backends/churchroad/Makefile.inc \
+  && cp /root/churchroad/yosys-plugin/churchroad.cc yosys-src/backends/churchroad/churchroad.cc \
+  && ./build.sh \
+  && cd npmjs \
+  && python3 prepare.py \
+  && npm install . \
+  && npm run all
+
+
+
+
diff --git a/churchroad b/churchroad
new file mode 160000
index 0000000..807296d
--- /dev/null
+++ b/churchroad
@@ -0,0 +1 @@
+Subproject commit 807296d32c800e20f6b1ed9034465f8c8b6ac53a
diff --git a/yosys b/yowasp-yosys
similarity index 100%
rename from yosys
rename to yowasp-yosys