整體來說環境搭建還是比較簡單的，我用的是wsl的ubuntu 18.04，直接下載了duo-buildroot-sdk-20230616.zip這個基于buildroot的SDK，然后確保安裝了cmake、device-tree-compiler、ninja、mtools、genext2fs等工具，原則上就是報錯缺什么就裝什么。

通過命令unzip duo-buildroot-sdk-20230616.zip -d ~/work/milkv/duo解壓duo-buildroot-sdk-20230616.zip到~/work/milkv/duo文件夾里面。

然后通過運行build_milkv.sh進行編譯和構建鏡像，build_milv.sh腳本的內容如下：

#!/bin/bash

MILKV_BOARD_ARRAY=
MILKV_BOARD_ARRAY_LEN=
MILKV_BOARD=
MILKV_BOARD_CONFIG=

MILKV_BOARD_DIR=milkv


function print_info()
{
  printf "e[1;32m%se[0mn" "$1"
}

function print_err()
{
  printf "e[1;31mError: %se[0mn" "$1"
}


# 自動檢測并下載工具集
function get_toolchain()
{
  if [ ! -d host-tools ]; then
    print_info "Toolchain does not exist, download it now..."

    toolchain_url="https://sophon-file.sophon.cn/sophon-prod-s3/drive/23/03/07/16/host-tools.tar.gz"
    echo "toolchain_url: ${toolchain_url}"
    toolchain_file=${toolchain_url##*/}
    echo "toolchain_file: ${toolchain_file}"

    wget ${toolchain_url} -O ${toolchain_file}
    if [ $? -ne 0 ]; then
      print_err "Failed to download ${toolchain_url} !"
      exit 1
    fi

    if [ ! -f ${toolchain_file} ]; then
      print_err "${toolchain_file} not found!"
      exit 1
    fi

    print_info "Extracting ${toolchain_file}..."
    tar -xf ${toolchain_file}
    if [ $? -ne 0 ]; then
      print_err "Extract ${toolchain_file} failed!"
      exit 1
    fi

    [ -f ${toolchain_file} ] && rm -rf ${toolchain_file}

  fi
}


# 這里得到了支持的板子MILKV_BOARD_ARRAY=milkv-duo
function get_available_board()
{
  MILKV_BOARD_ARRAY=( $(cd ${MILKV_BOARD_DIR}/; ls boardconfig*.sh | sort | awk -F"[-.]" -v OFS='-' '{print $2, $3}') )
  #echo ${MILKV_BOARD_ARRAY[@]}

  MILKV_BOARD_ARRAY_LEN=${#MILKV_BOARD_ARRAY[@]}
  if [ $MILKV_BOARD_ARRAY_LEN -eq 0 ]; then
    echo "No available board config"
    exit 1
  fi

  #echo ${MILKV_BOARD_ARRAY[@]} | xargs -n 1 | sed "=" | sed "N;s/n/. /"
}

function choose_milkv_board()
{
  # TODO
  echo "choose"
}

function prepare_env()
{
  source ${MILKV_BOARD_CONFIG}

  source build/${MV_BUILD_ENV} > /dev/null 2>&1
  defconfig ${MV_BOARD_LINK} > /dev/null 2>&1

  echo "OUTPUT_DIR: ${OUTPUT_DIR}"  # @build/milkvsetup.sh
}


# 執行編譯
function milkv_duo_build()
{
  # clean old img
  old_image_count=`ls ${OUTPUT_DIR}/*.img* | wc -l`
  if [ ${old_image_count} -ge 0 ]; then
    pushd ${OUTPUT_DIR}
    rm -rf *.img*
    popd
  fi


# 不需要重新編譯的時候可以把clean_all注釋掉，否則每次都會重新編譯
  clean_all
  build_all
  if [ $? -eq 0 ]; then
    print_info "Build board ${MILKV_BOARD} success!"
  else
    print_err "Build board ${MILKV_BOARD} failed!"
    exit 1
  fi
}


# 打包鏡像
function milkv_duo_pack()
{
  pack_sd_image

  [ ! -d out ] && mkdir out

  image_count=`ls ${OUTPUT_DIR}/*.img | wc -l`
  if [ ${image_count} -ge 0 ]; then
    mv ${OUTPUT_DIR}/*.img out/

    # rename milkv-duo.img file with time
    pushd out
    for img in *.img
    do
      if [ "${img}" == "${MILKV_BOARD}.img" ]; then
        mv $img ${MILKV_BOARD}-`date +%Y%m%d-%H%M`.img
      fi
    done
    popd

    # show latest img
    latest_img=`ls -t out/*.img | head -n1`
    if [ -z "${latest_img// }" ]; then
      print_err "Gen image failed!"
    else
      print_info "Gen image successful: ${latest_img}"
    fi
  else
    print_err "Create sd img failed!"
    exit 1
  fi
}

get_toolchain

get_available_board

if [ $MILKV_BOARD_ARRAY_LEN -eq 1 ]; then
  # Only one board
  print_info "Ready to build: ${MILKV_BOARD_ARRAY[0]}"
  MILKV_BOARD=${MILKV_BOARD_ARRAY[0]}
else
  # no arg
  if [ $# -lt 1 ]; then
    choose_milkv_board || exit 0
  fi

  # with board name
  if [ $# -ge 1 ]; then
    if [[ ${MILKV_BOARD_ARRAY[@]} =~ (^|[[:space:]])"${1}"($|[[:space:]]) ]]; then
      MILKV_BOARD=${1}
      echo "$MILKV_BOARD"
    else
      print_err "${1} not supported!"
      echo "Available boards: [ ${MILKV_BOARD_ARRAY[@]} ]"
      exit 1
    fi
  fi
fi

if [ -z "${MILKV_BOARD// }" ]; then
  print_err "No board specified!"
  exit 1
fi

export MILKV_BOARD="${MILKV_BOARD}"

MILKV_BOARD_CONFIG=${MILKV_BOARD_DIR}/boardconfig-${MILKV_BOARD}.sh

if [ ! -f ${MILKV_BOARD_CONFIG} ]; then
  print_err "${MILKV_BOARD_CONFIG} not found!"
  exit 1
fi

prepare_env

milkv_duo_build
milkv_duo_pack

腳本加了一些簡單的注釋，大體邏輯就是

1. 檢測并下載工具集；
2. 選擇板子；
3. 根據板子到處環境；
4. 執行編譯；
5. 構建鏡像；

最后腳本執行完成會輸出一個構建img成功的信息，如下圖綠色的內容，時間戳會根據構建時間而不一樣。

內核開發環境可以用了，可以學習內核代碼了，可以通過Windows下的vscode進行編輯然后在vscode終端里面進行編譯。

如果編譯過程遇到類似'Your PATH contains spaces, TABs, and/or newline (n) characters.'的錯誤，是因為WSL默認會自動添加Windows環境變量到wsl中，可以通過關閉自動添加，或是重新設置PATH來解決。我是選擇重新設置環境變量，即將帶空格的windows環境變量刪除，因為我需要使用windows下的vscode，如果關閉自動添加，就用不了windows下的軟件了。