Add dockerfile & make targets for risc-v toolchain

Makefile

@@ -1,4 +1,4 @@
-.PHONY: symbiyosys ghdl-formal all NOCACHE clean copy
+.PHONY: symbiyosys ghdl-formal riscv-gcc all NOCACHE clean copy
 
 # Support for make environment variable NOCACHE
 ifeq (NOCACHE,$(lastword $(MAKECMDGOALS)))
@@ -19,25 +19,27 @@ else
 endif
 
 
-all: symbiyosys ghdl-formal
+all: symbiyosys ghdl-formal riscv-gcc
 
-copy: ghdl-formal_${TAG}.tar.gz
+copy: copy-ghdl copy-riscv
+copy-ghdl: ghdl-formal_${TAG}.tar.gz
+copy-riscv: riscv-gcc_${TAG}.tar.gz
 
 
 .SECONDEXPANSION:
-symbiyosys ghdl-formal: $$@.Dockerfile
+symbiyosys ghdl-formal riscv-gcc: $$@.Dockerfile
 	docker build ${OPTIONS} -t $@:${TAG} -f $@.Dockerfile .
 
 
-ghdl-formal_${TAG}.tar.gz:
+%_${TAG}.tar.gz:
 	mkdir -p artefacts
-	docker run --rm -dit --name=ghdl-dummy ghdl-formal:${TAG} > /dev/null
-	docker cp ghdl-dummy:/opt/. artefacts
-	docker rm -f ghdl-dummy > /dev/null
+	docker run --rm -dit --name=$*-dummy $*:${TAG} > /dev/null
+	docker cp $*-dummy:/opt/. artefacts
+	docker rm -f $*-dummy > /dev/null
 	tar -C artefacts -czf $@ .
 	shasum --algorithm 256 --UNIVERSAL $@ > $@.sha256
 
 
 clean:
 	rm -rf artefacts
-	rm -f ghdl-formal_*.tar.*
+	rm -f *.tar.*

riscv-gcc.Dockerfile

@@ -0,0 +1,39 @@
+# Dockerfile to build Risc-V toolchain for
+# rv32i instruction set and ilp32 ABI
+# Useful to compile for NEORV32 target
+
+FROM debian:buster-slim as riscv-gcc
+
+# Get dependencies
+RUN apt-get update -qq && \
+    DEBIAN_FRONTEND=noninteractive apt-get -y install --no-install-recommends \
+    ca-certificates \
+    autoconf \
+    automake \
+    autotools-dev \
+    curl \
+    python3 \
+    libmpc-dev \
+    libmpfr-dev \
+    libgmp-dev \
+    gawk \
+    build-essential \
+    bison \
+    flex \
+    texinfo \
+    gperf \
+    libtool \
+    patchutils \
+    bc \
+    zlib1g-dev \
+    libexpat-dev \
+    git && \
+    apt-get autoclean && apt-get clean && apt-get -y autoremove && \
+    update-ca-certificates && \
+    rm -rf /var/lib/apt/lists/* && \
+    cd /root && \
+    git clone https://github.com/riscv/riscv-gnu-toolchain &&\
+    de riscv-gnu-toolchain && \
+    ./configure --prefix=/opt/riscv-gcc --with-arch=rv32i --with-abi=ilp32 && \
+    make && \
+    make clean