修改 buildroot的配置选项，增删软件包

cd builroot
make xxx_defconfig # xxx_defconfig 就在 buildroot 目录下中对应的板子文件
make menuconfig  # 字符图形化界面修改配置
make savedefconfig BR2_DEFCONFIG=configs/xxx_defconfig # 保存配置
# 如果编译不生效可以执行下列命令
make distclean
#buildroot目录大概这个样子
$ tree -L 1 buildroot/
buildroot/
├── arch
├── board
├── boot
├── CHANGES
├── Config.in
├── Config.in.legacy
├── configs
├── COPYING
├── DEVELOPERS
├── dl
├── docs
├── fs
├── linux
├── Makefile
├── Makefile.legacy
├── output
├── package
├── README
├── support
├── system
├── toolchain
└── utils

修改busybox的编译选项，增删命令

#下边的操作同样在 buildroot 目录中,
make busybox-menuconfig #如果这一步执行失败了需要先执行make xxx_defconfig
make busybox-update-config

以下仅为部分摘要 ,可以不读

make linux-update-defconfig saves the linux configuration to the path specified by BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE. It simplifies the config file by removing default values. However, this only works with kernels starting from 2.6.33. For earlier kernels, use make linux-update-config.
make busybox-update-config saves the busybox configuration to the path specified by BR2_PACKAGE_BUSYBOX_CONFIG.
make uclibc-update-config saves the uClibc configuration to the path specified by BR2_UCLIBC_CONFIG.
make barebox-update-defconfig saves the barebox configuration to the path specified by BR2_TARGET_BAREBOX_CUSTOM_CONFIG_FILE.
make uboot-update-defconfig saves the U-Boot configuration to the path specified by BR2_TARGET_UBOOT_CUSTOM_CONFIG_FILE.
For at91bootstrap3, no helper exists so you have to copy the config file manually to BR2_TARGET_AT91BOOTSTRAP3_CUSTOM_CONFIG_FILE.

https://buildroot.org/downloads/manual/manual.html