make -C $(buildroot 文件夹路径) BR2_EXTERNAL=$(BR2_EXTERNAL_XXX_PATH)，可以不修改 buildroot/package 路径下的内容实现编译引用外部 package
BR2_EXTERNAL_XXX_PATH 文件夹需要包含如下三个文件：
external.desc external.mk Config.in
external.mk 包含所有 package 的 mk 文件，内容可为
include $(sort $(wildcard $(BR2_EXTERNAL_XXX_PATH)/package/*/*.mk))
Config.in 包含 package 的 Config.in，如：
source "$BR2_EXTERNAL_REMO_PATH/package/remo-sdk/Config.in" source "$BR2_EXTERNAL_REMO_PATH/package/thirdparty/Config.in.host" source "$BR2_EXTERNAL_REMO_PATH/package/thirdparty/Config.in" source "$BR2_EXTERNAL_REMO_PATH/package/tools/Config.in.host"
external.desc 包含描述信息，如：
name: REMO desc: remo vendor-specific buildroot directory.
标签：buildroot,package,BR2,EXTERNAL,PATH,Config From： https://www.cnblogs.com/god-of-death/p/18260738