使用buildroot制作根文件系统（龙芯1B使用）

buildroot-2016.02.tar.bz2 //可以去Buildroot官方下载，
dl //内涵部分网络第三方库，提前准备的，没有没关系，在make编译的时候在线下载即可。
buildroot-2016.02-glibc-gcc-4.9.x-mips32-nofpu_defconfig //龙芯4.9编译器默认配置选项，具体参数可以参考后面。

Target options  --->
   Target Architecture (MIPS (little endian))  --->
   Target Binary Format (ELF)  --->
   Target Architecture Variant (mips 32)  --->
  [*] Use soft-float
 Build options  --->
   该目录下使用默认配置即可
   其中
   Mirrors and Download locations  --->
     (http://mirrors4.ustc.edu.cn/gnu) GNU Software mirror

Toolchain  --->
       Toolchain type (Buildroot toolchain)  --->
   (buildroot) custom toolchain vendor name
       *** Kernel Header Options ***
       Kernel Headers (Linux 3.18.x kernel headers)  --->
       C library (glibc)  --->
       glibc version (2.22)  --->
       *** Binutils Options ***
       Binutils Version (binutils 2.24)  --->
   ()  Additional binutils options
       *** GCC Options ***
       GCC compiler Version (gcc 4.9.x)  --->
   ()  Additional gcc options
   [*] Enable C++ support
   [ ] Enable Fortran support
   [*] Enable compiler link-time-optimization support
   [ ] Enable compiler OpenMP support
   [ ] Enable graphite support
   [ ] Build cross gdb for the host
   [ ] Purge unwanted locales
   ()  Generate locale data
   [ ] Copy gconv libraries
   ()  Target Optimizations
   ()  Target linker options
   [ ] Register toolchain within Eclipse Buildroot plug-in

System configuration  --->
   (buildroot) System hostname
   (Welcome to Buildroot) System banner
       Passwords encoding (md5)  --->
       Init system (None)  --->
       /dev management (Dynamic using devtmpfs only)  --->
   (system/device_table.txt) Path to the permission tables
       Root FS skeleton (default target skeleton)  --->
   [ ] Use symlinks to /usr for /bin, /sbin and /lib
   [ ] Enable root login with password
       /bin/sh (none)  --->
   [ ] Run a getty (login prompt) after boot  ----
   [ ] remount root filesystem read-write during boot
       *** automatic network configuration via DHCP needs ifupdown or busybox ***
   [ ] Install timezone info
   ()  Path to the users tables
   ()  Root filesystem overlay directories
   ()  Custom scripts to run before creating filesystem images
   ()  Custom scripts to run after creating filesystem images

Kernel  --->
 Target packages  --->
 Filesystem images  --->
 Bootloaders  --->
 Host utilities  --->
 Legacy config options  --->

#
# Automatically generated file; DO NOT EDIT.
# Buildroot 2016.02 Configuration
#
BR2_HAVE_DOT_CONFIG=y
BR2_HOST_GCC_AT_LEAST_4_7=y
BR2_HOST_GCC_AT_LEAST_4_8=y
#
# Target options
#
BR2_SOFT_FLOAT=y
BR2_ARCH_HAS_MMU_MANDATORY=y
BR2_mipsel=y
BR2_ARCH="mipsel"
BR2_ENDIAN="LITTLE"
BR2_GCC_TARGET_ARCH="mips32"
BR2_GCC_TARGET_ABI="32"
BR2_BINFMT_SUPPORTS_SHARED=y
BR2_BINFMT_ELF=y
BR2_mips_32=y
BR2_MIPS_SOFT_FLOAT=y
BR2_MIPS_OABI32=y
#
# Build options
#
#
# Commands
#
BR2_WGET="wget --passive-ftp -nd -t 3"
BR2_SVN="svn"
BR2_BZR="bzr"
BR2_GIT="git"
BR2_CVS="cvs"
BR2_LOCALFILES="cp"
BR2_SCP="scp"
BR2_SSH="ssh"
BR2_HG="hg"
BR2_ZCAT="gzip -d -c"
BR2_BZCAT="bzcat"
BR2_XZCAT="xzcat"
BR2_TAR_OPTIONS=""
BR2_DEFCONFIG="$(CONFIG_DIR)/defconfig"
BR2_DL_DIR="$(TOPDIR)/dl"
BR2_HOST_DIR="$(BASE_DIR)/host"
#
# Mirrors and Download locations
#
BR2_PRIMARY_SITE=""
BR2_BACKUP_SITE="http://sources.buildroot.net"
BR2_KERNEL_MIRROR="https://www.kernel.org/pub"
BR2_GNU_MIRROR="http://mirrors4.ustc.edu.cn/gnu"
BR2_LUAROCKS_MIRROR="http://rocks.moonscript.org"
BR2_CPAN_MIRROR="http://cpan.metacpan.org"
BR2_JLEVEL=0
BR2_STRIP_strip=y
BR2_STRIP_EXCLUDE_FILES=""
BR2_STRIP_EXCLUDE_DIRS=""
BR2_OPTIMIZE_S=y
BR2_SSP_NONE=y
BR2_SHARED_LIBS=y
BR2_PACKAGE_OVERRIDE_FILE="$(CONFIG_DIR)/local.mk"
BR2_GLOBAL_PATCH_DIR=""
#
# Advanced
#
# BR2_COMPILER_PARANOID_UNSAFE_PATH is not set
#
# Toolchain
#
BR2_TOOLCHAIN=y
BR2_TOOLCHAIN_USES_GLIBC=y
BR2_TOOLCHAIN_BUILDROOT=y
BR2_TOOLCHAIN_BUILDROOT_VENDOR="buildroot"
#
# Kernel Header Options
#
BR2_KERNEL_HEADERS_3_18=y
BR2_DEFAULT_KERNEL_HEADERS="3.18.27"
BR2_TOOLCHAIN_BUILDROOT_GLIBC=y
BR2_TOOLCHAIN_BUILDROOT_LIBC="glibc"
BR2_PACKAGE_LINUX_HEADERS=y
BR2_PACKAGE_GLIBC=y
BR2_GLIBC_VERSION_2_22=y
BR2_GLIBC_VERSION_STRING="2.22"
#
# Binutils Options
#
BR2_BINUTILS_VERSION_2_24_X=y
BR2_BINUTILS_VERSION="2.24"
BR2_BINUTILS_ENABLE_LTO=y
BR2_BINUTILS_EXTRA_CONFIG_OPTIONS=""
#
# GCC Options
#
BR2_GCC_NEEDS_MPC=y
BR2_GCC_SUPPORTS_GRAPHITE=y
BR2_GCC_VERSION_4_9_X=y
BR2_GCC_SUPPORTS_FINEGRAINEDMTUNE=y
BR2_GCC_VERSION="4.9.3"
BR2_EXTRA_GCC_CONFIG_OPTIONS=""
BR2_TOOLCHAIN_BUILDROOT_CXX=y
BR2_GCC_ENABLE_TLS=y
BR2_GCC_ENABLE_LTO=y
BR2_TOOLCHAIN_HAS_NATIVE_RPC=y
BR2_USE_WCHAR=y
BR2_ENABLE_LOCALE=y
BR2_INSTALL_LIBSTDCPP=y
BR2_TOOLCHAIN_HAS_THREADS=y
BR2_TOOLCHAIN_HAS_THREADS_DEBUG=y
BR2_TOOLCHAIN_HAS_THREADS_NPTL=y
BR2_TOOLCHAIN_HAS_SHADOW_PASSWORDS=y
BR2_TOOLCHAIN_HAS_SSP=y
BR2_GENERATE_LOCALE=""
BR2_USE_MMU=y
BR2_TARGET_OPTIMIZATION=""
BR2_TARGET_LDFLAGS=""
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_0=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_1=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_2=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_3=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_4=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_5=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_6=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_7=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_8=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_9=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_10=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_11=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_12=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_13=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_14=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_15=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_16=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_17=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_18=y
BR2_TOOLCHAIN_HEADERS_AT_LEAST="3.18"
BR2_TOOLCHAIN_GCC_AT_LEAST_4_3=y
BR2_TOOLCHAIN_GCC_AT_LEAST_4_4=y
BR2_TOOLCHAIN_GCC_AT_LEAST_4_5=y
BR2_TOOLCHAIN_GCC_AT_LEAST_4_6=y
BR2_TOOLCHAIN_GCC_AT_LEAST_4_7=y
BR2_TOOLCHAIN_GCC_AT_LEAST_4_8=y
BR2_TOOLCHAIN_GCC_AT_LEAST_4_9=y
BR2_TOOLCHAIN_GCC_AT_LEAST="4.9"
BR2_TOOLCHAIN_HAS_SYNC_1=y
BR2_TOOLCHAIN_HAS_SYNC_2=y
BR2_TOOLCHAIN_HAS_SYNC_4=y
BR2_TOOLCHAIN_HAS_ATOMIC=y
#
# System configuration
#
BR2_TARGET_GENERIC_HOSTNAME="buildroot"
BR2_TARGET_GENERIC_ISSUE="Welcome to Buildroot"
BR2_TARGET_GENERIC_PASSWD_MD5=y
BR2_TARGET_GENERIC_PASSWD_METHOD="md5"
BR2_INIT_NONE=y
BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_DEVTMPFS=y
BR2_ROOTFS_DEVICE_TABLE="system/device_table.txt"
BR2_ROOTFS_SKELETON_DEFAULT=y
BR2_SYSTEM_BIN_SH_NONE=y
BR2_ROOTFS_USERS_TABLES=""
BR2_ROOTFS_OVERLAY=""
BR2_ROOTFS_POST_BUILD_SCRIPT=""
BR2_ROOTFS_POST_IMAGE_SCRIPT=""
#
# Kernel
#
# BR2_LINUX_KERNEL is not set
#
# Target packages
#
# BR2_PACKAGE_BUSYBOX is not set
BR2_PACKAGE_BUSYBOX_SHOW_OTHERS=y
BR2_PACKAGE_SKELETON=y
#
# Audio and video applications
#
BR2_PACKAGE_KODI_ARCH_SUPPORTS=y
BR2_PACKAGE_MPLAYER_ARCH_SUPPORTS=y
BR2_PACKAGE_GOOGLE_BREAKPAD_ARCH_SUPPORTS=y
BR2_PACKAGE_CMAKE_ARCH_SUPPORTS=y
#
# Other GUIs
#
BR2_PACKAGE_QT5_JSCORE_AVAILABLE=y
#
# Interpreter languages and scripting
#
BR2_PACKAGE_GAUCHE_ARCH_SUPPORTS=y
BR2_PACKAGE_MONO_ARCH_SUPPORTS=y
BR2_PACKAGE_OPENAL_ARCH_SUPPORTS=y
#
# Crypto
#
BR2_PACKAGE_BOTAN_ARCH_SUPPORTS=y
BR2_PACKAGE_WEBKITGTK24_ARCH_SUPPORTS=y
BR2_PACKAGE_LIBAIO_ARCH_SUPPORTS=y
BR2_PACKAGE_LIBOPENH264_ARCH_SUPPORTS=y
BR2_PACKAGE_BOOST_ARCH_SUPPORTS=y
BR2_PACKAGE_LIBBSD_ARCH_SUPPORTS=y
BR2_PACKAGE_LIBNSPR_ARCH_SUPPORT=y
BR2_PACKAGE_LIBUNWIND_ARCH_SUPPORTS=y
BR2_PACKAGE_PROTOBUF_ARCH_SUPPORTS=y
BR2_PACKAGE_QEMU_ARCH_SUPPORTS_TARGET=y
BR2_PACKAGE_MONGREL2_LIBC_SUPPORTS=y
BR2_PACKAGE_SYSTEMD_ARCH_SUPPORTS=y
BR2_PACKAGE_TZDATA_ZONELIST=""
BR2_TARGET_UBOOT_CUSTOM_GIT_REPO_URL=""
BR2_TARGET_UBOOT_CUSTOM_GIT_VERSION=""
BR2_LINUX_KERNEL_CUSTOM_GIT_REPO_URL=""
BR2_LINUX_KERNEL_CUSTOM_GIT_VERSION=""

cd /home/loongson/tools/buildroot/
  tar -xvf buildroot-2016.02.tar.bz2
  cd buildroot-2016.02
  cp -r /mnt/dl ./
  cp /mnt/buildroot-2016.02-glibc-gcc-4.9.x-mips32-nofpu_defconfig .config
  make menuconfig
//  保存退出
  make

export PATH=/home/loongson/tools/buildroot/buildroot-2016.02/output/host/usr/bin:$PATH

make
make sdk //制作sdk环境包