Source code taken from:

https://github.com/sherpya/android-busybox

No changes to the original source code were done. 

Homepage of the BUSYBOX project:

https://busybox.net/

License: GPL (v.2)

Compilation:

(0) prepare the standalone Android-NDK toolchain according to the manual presented 
    in the above cited source package (change the file api-level.h)
(1) export necessary environmental variables in Linux PC (it will probably
    work under Cygwin as well - not tested):
    export PATH="/YOUR/PATH/android-toolchain/x86_64/bin:/YOUR/PATH/android-toolchain/x86_64/include:/usr/local/bin:/usr/bin:/bin:$PATH" 
(2) check if the previous step was done correctly by typing:
    x86_64-linux-android-gcc -v
    if you obtain respond from the cross-compiler, it is OK
(3) open file configs/sherpya_android_defconfig, change line 54 appropriately:
    CONFIG_CROSS_COMPILER_PREFIX="x86_64-linux-android-"
(4) compile:
    make sherpya_android_defconfig
    make
    make install

The resulting binaries are designed to be run in terminal environment under Android 4.1 or newer. 