All working.

docker/Dockerfile.build

@@ -0,0 +1,24 @@
+FROM debian:bullseye AS builder
+
+RUN apt-get update && apt-get install -y \
+    build-essential \
+    cmake \
+    pkg-config \
+    bash \
+    gcc-aarch64-linux-gnu \
+    g++-aarch64-linux-gnu \
+    binutils-aarch64-linux-gnu \
+    qemu-user-static
+
+WORKDIR /app
+
+COPY . .
+
+COPY --chmod=755 docker/_create_dropshell.sh /scripts/
+
+RUN rm -rf build
+
+ENV CXXFLAGS="-static-libstdc++ -static-libgcc"
+ENV LDFLAGS="-static -pthread -Wl,--whole-archive -lpthread -Wl,--no-whole-archive"
+
+CMD ["/bin/bash","/scripts/_create_dropshell.sh"]