Update Zephyr document, add esp32c3 and particle_argon support(#920)

Update the Zephyr document to provide more detailed instructions, and add info
about espressif toolchain too.

Add ESP32C3 (RISC-V) and Particle Argon boards support to the zephyr platform
sample. More boards are possible, but the script doesn't scale well and is to be
improved in future.

Add Dockerfile to kickstart a Zephyr development environment as it can be rather
confusing for new users.

doc/build_wamr.md

@@ -306,16 +306,25 @@ WAMR provides some features which can be easily configured by passing options to
 
 Zephyr
 -------------------------
-You need to download the Zephyr source code first and embed WAMR into it.
+You need to prepare Zephyr first as described here https://docs.zephyrproject.org/latest/getting_started/index.html#get-zephyr-and-install-python-dependencies).
+
+After that you need to point the `ZEPHYR_BASE` variable to e.g. `~/zephyrproject/zephyr`. Also, it is important that you have `west` available for subsequent actions.
+
 ``` Bash
-git clone https://github.com/zephyrproject-rtos/zephyr.git
-source zephyr/zephyr-env.sh
 cd <wamr_root_dir>/product-mini/platforms/zephyr/simple
 # Execute the ./build_and_run.sh script with board name as parameter. Here take x86 as example:
 ./build_and_run.sh x86
+```
 
+If you want to use the Espressif toolchain (esp32 or esp32c3), you can most conveniently install it with `west`:
+
+``` Bash
+cd $ZEPHYR_BASE
+west espressif install
 ```
 
+After that set `ESPRESSIF_TOOLCHAIN_PATH` according to the output, for example `~/.espressif/tools/zephyr`.
+
 Note:
 WAMR provides some features which can be easily configured by passing options to cmake, please see [WAMR vmcore cmake building configurations](./build_wamr.md#wamr-vmcore-cmake-building-configurations) for details. Currently in Zephyr, interpreter, AoT and builtin libc are enabled by default.
 

product-mini/platforms/zephyr/simple/Dockerfile

@@ -0,0 +1,34 @@
+FROM ubuntu:20.04
+
+ARG DOCKER_UID=1000
+
+ENV DEBIAN_FRONTEND noninteractive
+
+RUN apt-get -qq update && apt-get -qq dist-upgrade && apt install -qq -y python3-pip git wget ninja-build
+
+WORKDIR /tmp
+
+RUN mkdir /opt/cmake && wget -q https://github.com/Kitware/CMake/releases/download/v3.22.1/cmake-3.22.1-linux-x86_64.sh && sh cmake-3.22.1-linux-x86_64.sh --skip-license --prefix=/opt/cmake && rm cmake-3.22.1-linux-x86_64.sh
+
+ENV PATH="/opt/cmake/bin:$PATH"
+
+RUN useradd -m wamr -u ${DOCKER_UID} -G dialout
+
+USER wamr
+
+ENV PATH="/home/wamr/.local/bin:$PATH"
+
+RUN pip3 install --user west
+
+RUN west init ~/zephyrproject && cd ~/zephyrproject && west update && west zephyr-export
+
+RUN pip3 install --user -r ~/zephyrproject/zephyr/scripts/requirements.txt
+
+WORKDIR /home/wamr/zephyrproject
+
+RUN west espressif install
+
+ENV ZEPHYR_BASE=/home/wamr/zephyrproject/zephyr
+ENV ESPRESSIF_TOOLCHAIN_PATH=/home/wamr/.espressif/tools/zephyr
+
+WORKDIR /home/wamr/source/product-mini/platforms/zephyr/simple

product-mini/platforms/zephyr/simple/README_docker.md

@@ -0,0 +1,25 @@
+# Build with Docker
+
+To have a quicker start, a Docker container of the Zephyr setup can be generated.
+
+## Build Docker container
+
+``` Bash
+docker build --build-arg DOCKER_UID=$(id -u) . -t wamr-zephyr
+```
+
+## Run Docker container to build images
+
+Enter the docker container (maps the toplevel wasm-micro-runtime repo as volume):
+
+``` Bash
+docker run -ti -v $PWD/../../../..:/home/wamr/source --device=/dev/ttyUSB0 wamr-zephyr
+```
+
+Adopt the device or remove if not needed.
+
+And then in the docker container:
+
+``` Bash
+./build_and_run.sh esp32c3
+```

product-mini/platforms/zephyr/simple/build_and_run.sh

@@ -6,6 +6,8 @@
 X86_TARGET="x86"
 STM32_TARGET="stm32"
 ESP32_TARGET="esp32"
+ESP32C3_TARGET="esp32c3"
+PARTICLE_ARGON_TARGET="particle_argon"
 QEMU_CORTEX_A53="qemu_cortex_a53"
 QEMU_XTENSA_TARGET="qemu_xtensa"
 QEMU_RISCV64_TARGET="qemu_riscv64"
@@ -15,11 +17,13 @@ QEMU_ARC_TARGET="qemu_arc"
 usage ()
 {
         echo "USAGE:"
-        echo "$0 $X86_TARGET|$STM32_TARGET|$ESP32_TARGET|$QEMU_CORTEX_A53|$QEMU_XTENSA_TARGET|$QEMU_RISCV64_TARGET|$QEMU_RISCV32_TARGET|$QEMU_ARC_TARGET"
+        echo "$0 $X86_TARGET|$STM32_TARGET|$ESP32_TARGET|$ESP32C3_TARGET|$PARTICLE_ARGON_TARGET|$QEMU_CORTEX_A53|$QEMU_XTENSA_TARGET|$QEMU_RISCV64_TARGET|$QEMU_RISCV32_TARGET|$QEMU_ARC_TARGET"
         echo "Example:"
         echo "        $0 $X86_TARGET"
         echo "        $0 $STM32_TARGET"
         echo "        $0 $ESP32_TARGET"
+        echo "        $0 $ESP32C3_TARGET"
+        echo "        $0 $PARTICLE_ARGON_TARGET"
         echo "        $0 $QEMU_CORTEX_A53"
         echo "        $0 $QEMU_XTENSA_TARGET"
         echo "        $0 $QEMU_RISCV64_TARGET"
@@ -47,14 +51,35 @@ case $TARGET in
                 west flash
                 ;;
         $ESP32_TARGET)
-                # suppose you have set environment variable ESP_IDF_PATH
+                export ZEPHYR_TOOLCHAIN_VARIANT="espressif"
+                if [[ -z "${ESPRESSIF_TOOLCHAIN_PATH}" ]]; then
+                        echo "Set ESPRESSIF_TOOLCHAIN_PATH to your espressif toolchain"
+                        exit 1
+                fi
                 west build -b esp32 \
                            . -p always -- \
-                           -DESP_IDF_PATH=$ESP_IDF_PATH \
-                           -DWAMR_BUILD_TARGET=XTENSA
-                # suppose the serial port is /dev/ttyUSB1 and you should change to
-                # the real name accordingly
-                west flash --esp-device /dev/ttyUSB1
+                           -DWAMR_BUILD_TARGET=XTENSA                           
+                # west flash will discover the device
+                west flash
+                ;;
+        $ESP32C3_TARGET)
+                export ZEPHYR_TOOLCHAIN_VARIANT="espressif"
+                if [[ -z "${ESPRESSIF_TOOLCHAIN_PATH}" ]]; then
+                        echo "Set ESPRESSIF_TOOLCHAIN_PATH to your espressif toolchain"
+                        exit 1
+                fi
+                west build -b esp32c3_devkitm \
+                           . -p always -- \
+                           -DWAMR_BUILD_TARGET=RISCV32_ILP32
+                # west flash will discover the device
+                west flash
+                ;;
+        $PARTICLE_ARGON_TARGET)
+                west build -b  particle_argon \
+                           . -p always -- \
+                           -DWAMR_BUILD_TARGET=THUMBV7
+                # west flash will discover the device
+                west flash
                 ;;
         $QEMU_XTENSA_TARGET)
                 west build -b qemu_xtensa \