Add gdb support

Dockerfile

@@ -1,37 +1,46 @@
+# syntax=docker/dockerfile:1
 FROM ubuntu:kinetic
 ARG uid
 ARG gid
+ARG tag=2022.11.23
 CMD /bin/bash
 RUN apt-get update && apt-get install -y \
-	    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 \
-	    meson
+	autoconf \
+	automake \
+	autotools-dev \
+	curl \
+	python3 \
+	libmpc-dev \
+	libmpfr-dev \
+	libgmp-dev \
+	libncurses5-dev \
+	gawk \
+	build-essential \
+	bison \
+	flex \
+	texinfo \
+	gperf \
+	libtool \
+	patchutils \
+	bc \
+	zlib1g-dev \
+	libexpat-dev \
+	git \
+	meson \
+	nano
 
-RUN git clone https://github.com/riscv-collab/riscv-gnu-toolchain /build-toolchain
-WORKDIR /build-toolchain
+RUN git clone https://github.com/riscv-collab/riscv-gnu-toolchain /build
+WORKDIR /build
+RUN git checkout ${tag}
+
+# Patch the build to include the gdb TUI, this makes debugging inside docker
+# much nicer
+RUN sed -i.bak 's/--disable-gprof/--disable-gprof --enable-tui/' Makefile.in
 RUN ./configure --prefix=/usr/local \
 		--with-arch=rv32gc --with-abi=ilp32d --with-abi=ilp32 && \
 	make -j $(nproc) && \
 	make install && \
-	rm -rf /build-toolchain
+	rm -rf /build
 
 # groupadd will fail if the GID already exists, as is the case for macOS hosts
 # where "staff" is gid 20. That's ok. We just need the group to exist.

Makefile

@@ -1,10 +1,11 @@
 .PHONY: \
-	all \
-	lall \
-	wipe clean shell flash
+	all gdb \
+	lall lgdb \
+	clean flash openocd shell wipe
 
 DOCKER_IMAGE ?= riscv-ubuntu
-DOCKER_CMD   ?= docker run --rm -it -v ${PWD}:/project ${DOCKER_IMAGE}
+DOCKER_CMD   ?= docker run --rm -it -v ${PWD}:/project
+LOCALHOST    ?= localhost
 
 MESON_FILE   := meson.build
 MESON_CROSS  ?= meson_cross_riscv.txt
@@ -13,7 +14,7 @@ MESON_DIR    ?= mbuild
 OPENOCD_DIR  ?= $(dir $(shell command -v openocd))/..
 
 all: .have_docker
-	${DOCKER_CMD} make lall
+	${DOCKER_CMD} ${DOCKER_IMAGE} make lall
 wipe: clean all
 
 lall: ${MESON_DIR}
@@ -27,16 +28,31 @@ clean:
 	rm .have_docker
 
 shell: .have_docker
-	${DOCKER_CMD} bash
+	${DOCKER_CMD} ${DOCKER_IMAGE} bash
 
 flash: all
 	${OPENOCD_DIR}/bin/openocd \
 		-s ${OPENOCD_DIR}/scripts \
 		-f ./wch-riscv.cfg \
 		-c init -c halt \
-		-c "program $(shell readlink -f ${MESON_DIR}/firmware-for-makeflash.hex) verify reset" \
+		-c "program $(shell readlink -f ${MESON_DIR}/firmware-for-make.hex) verify reset" \
 		-c resume -c exit
 
+openocd:
+	${OPENOCD_DIR}/bin/openocd \
+		-s ${OPENOCD_DIR}/scripts \
+		-f ./wch-riscv.cfg \
+		-c init
+
+gdb: .have_docker
+	${DOCKER_CMD} --add-host=host.docker.internal:host-gateway \
+		-e COLUMNS=$(shell tput cols) -e LINES=$(shell tput lines) -e TERM \
+		${DOCKER_IMAGE} make LOCALHOST=host.docker.internal lgdb
+
+lgdb:
+	cd ${MESON_DIR} && \
+	riscv32-unknown-elf-gdb ./firmware-for-make.elf -ex "tar ext ${LOCALHOST}:3333"
+
 .have_docker: Dockerfile
 	docker build -t ${DOCKER_IMAGE} \
 		--build-arg uid=$(shell id -u) --build-arg gid=$(shell id -g) \

README.md

@@ -30,6 +30,27 @@ Everything else is downloaded into the Docker container.
 `make flash` expects to find a WCH-compatible patched openocd on the system
 PATH. If yours lives elsewhere, define `OPENOCD_DIR` on the environment.
 
+## Using gdb
+
+The Docker container has gdb too. To debug, first launch openocd:
+
+```
+make openocd
+```
+
+Next, launch gdb:
+
+```
+make gdb
+```
+
+This make target will launch gdb inside Docker, routing openocd port 3333 from
+the container to the host, and automatically load the firmware file and connect
+to openocd.
+
+As above, if you're not using Docker, `make lgdb` will launch gdb locally,
+also automatically loading the firmware and connecting.
+
 ## What's in here?
 
 The directory tree contains:

meson.build

@@ -88,12 +88,19 @@ main_hex = custom_target(
   build_by_default: true,
 )
 
-# Copy the .hex to a generic name that `make flash` can find.
+# Copy files to generic names that make can find
 hex_for_make = custom_target(
-  'firmware-for-makeflash.hex',
+  'firmware-for-make.hex',
   command: ['cp', '@INPUT@', '@OUTPUT@'],
   input: main_hex,
-  output: 'firmware-for-makeflash.hex',
+  output: 'firmware-for-make.hex',
+  build_by_default: true,
+)
+elf_for_make = custom_target(
+  'firmware-for-make.elf',
+  command: ['cp', '@INPUT@', '@OUTPUT@'],
+  input: main,
+  output: 'firmware-for-make.elf',
   build_by_default: true,
 )