To cross compile for Android Oreo 64 bit
========================================

1) Install "termux" app in cellphone.

2) In termux, install openssh:
   (Termux can't read files from file managers nor from AndFTP).
        pkg install openssh
   Also, having ldd and file might be useful:
        pkg install binutils
        pkg install file

3) In the Linux PC (I'm using Kubuntu 18.04 64-bit), install the GCC cross compiler for AARCH64:
        apt-get install gcc-aarch64-linux-gnu:amd64

4) Test hello world:

    In the PC:
        ---hello.c---
        #include <stdio.h>
        int main (int argc, char** argv) {
            printf("IT WORKS!\n");
            return 0;
        }
        -------------

        aarch64-linux-gnu-gcc -static -o hello hello.c

        file hello
        hello: ELF 64-bit LSB executable, ARM aarch64, version 1 (GNU/Linux), statically linked, for GNU/Linux 3.7.0, BuildID[sha1]=635beace2f9a04e57c4bc427f0c70fd28ec338da, not stripped

    I thought -static was not supposed to work with these newer Android's, but it works.
    Of course, being static, passing -fPIC has no effect, and the resulting binary is exactly the same.
    Under termux, it runs well.

    In the cell phone under Termux:

        sftp -oPort=<your_SSH_port> myuser@myComputerIPAddress

        cd /path/to/hello/binary
        get hello
        exit

        ./hello
        IT WORKS!

    The following shortcuts can be issued from Termux:

        VOLUME_UP + W       -->     UP ARROW
        VOLUME_UP + S       -->     DOWN ARROW
        VOLUME_UP + T       -->     TAB
        VOLUME_DOWN + C     -->     CTRL+C
        VOLUME_DOWN + D     -->     CTRL+D
        VOLUME_DOWN + Z     -->     CTRL+Z

5) Repeat the steps used for hello but for benchmark.c and nbench.

DONE!
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