Simulation documentation: add Docker instructions

doc/dev/simulation.md

@@ -26,6 +26,67 @@ fusesoc --cores-root=. run \
 
 *To enable tracing append, `--verilator_options='+define+RVFI'` to the command above.*
 
+## Notes on building natively
+
+**This is only for advanced users.**
+
+If for some reason you do not want to use the nix environment and need to set up your own environment, here are some commands that you can use if you're running using podman or Docker:
+
+```Dockerfile
+# Download LLVM toolchain
+FROM ubuntu:24.04 as llvm-download
+RUN apt update && apt install -y curl unzip
+RUN curl -O https://api.cirrus-ci.com/v1/artifact/github/CHERIoT-Platform/llvm-project/Build%20and%20upload%20artefact%20$(uname -p)/binaries.zip
+RUN unzip binaries.zip
+
+# Build Verilator
+FROM ubuntu:24.04 AS verilator-build
+# Verilator dependencies
+RUN apt update && apt install -y git help2man perl python3 make g++ libfl2 libfl-dev zlib1g zlib1g-dev autoconf flex bison
+WORKDIR /
+# Build Verilator
+RUN git clone https://github.com/verilator/verilator
+WORKDIR verilator
+RUN git checkout v5.024
+RUN mkdir install
+RUN autoconf \
+    && ./configure --prefix=/verilator/install \
+    && make -j `nproc` \
+    && make install
+
+# Build Sonata simulator
+FROM ubuntu:24.04 as sonata-build
+# Sonata dependencies
+RUN apt update && apt install -y git python3 python3-venv build-essential libelf-dev libxml2-dev
+# Install LLVM for sim boot stub.
+RUN mkdir -p /cheriot-tools/bin
+COPY --from=llvm-download "/Build/install/bin/clang-13" "/Build/install/bin/lld" "/Build/install/bin/llvm-objcopy" "/Build/install/bin/llvm-objdump" "/Build/install/bin/clangd" "/Build/install/bin/clang-format" "/Build/install/bin/clang-tidy" /cheriot-tools/bin/
+# Create the LLVM tool symlinks.
+RUN cd /cheriot-tools/bin \
+    && ln -s clang-13 clang \
+    && ln -s clang clang++ \
+    && ln -s lld ld.lld \
+    && ln -s llvm-objcopy objcopy \
+    && ln -s llvm-objdump objdump \
+    && chmod +x *
+COPY --from=verilator-build "/verilator/install" /verilator
+WORKDIR /
+# Build Sonata simulator
+RUN git clone https://github.com/lowRISC/sonata-system
+WORKDIR sonata-system
+RUN python3 -m venv .venv \
+    && . .venv/bin/activate \
+    && pip install -r python-requirements.txt \
+    && export PATH=/verilator/bin:$PATH \
+    && fusesoc --cores-root=. run --target=sim --tool=verilator --setup --build lowrisc:sonata:system
+RUN cp build/lowrisc_sonata_system_0/sim-verilator/Vtop_verilator /sonata_simulator
+# Build Sonata simulator boot stub
+WORKDIR sw/cheri/sim_boot_stub
+RUN export PATH=/cheriot-tools/bin:$PATH \
+    && make
+RUN cp sim_boot_stub /sonata_simulator_boot_stub
+```
+
 ## Running baremetal
 
 Running the simulator can be accomplished with the following command, where you can change the `meminit` argument to a different program if you wish: