Download :
mega.nz

gl-ar300m-rt25-v7-src-packaages-2019-21_59_55.tar.7z

Viertualbox ubuntu server best performance and resource availabilit

virtualbox osboxes.org ( more than 8 core not needed but better than an vps with low voltage / low budget system
or
get an vps at bithost.io with 8 vcore 

OS:
Ubuntu 16.04.6 (LTS) x64

CLI at srv:

apt update

apt-get -y  install subversion build-essential git-core libncurses5-dev zlib1g-dev gawk flex quilt libssl-dev xsltproc libxml-parser-perl mercurial bzr ecj cvs unzip git wget subversion build-essential binutils flex bison autoconf gettext texinfo sharutils subversion ncurses-dev zlib1g-dev rsync gawk unzip screen mc rsync tcpdump net-tools tftpd wget build-essential binutils flex bison autoconf gettext texinfo sharutils subversion libncurses5-dev zlib1g-dev rsync gawk unzip screen mc rsync tcpdump net-tools tftpd wget subversion build-essential libncurses5-dev zlib1g-dev gawk git ccache gettext libssl-dev xsltproc zip build-essential libncurses5-dev gawk git libssl-dev gettext zlib1g-dev swig unzip time build-essential libncurses5-dev gawk git libssl-dev gettext unzip zlib1g-dev file python libncurses5-dev zlib1g-dev gawk binutils bzip2 gcc gawk gettext flex make patch unzip sed sdcc intltool sharutils bison wget git-core sudo

apt -y install python-dev python-setuptools

apt-get -y install subversion g++ ncurses-term zlib1g-dev gawk flex patch openssh-server minicom picocom tftp tftpd gettext libncurses5 libncurses5-dev unzip quilt git git-doc git-gui libxml-parser-perl libssl-dev

apt-get -y install cmake bison flex libicu-dev

apt-get -y install nvidia-opencl-dev

apt-get -y install yasm libgmp-dev libpcap-dev pkg-config libbz2-dev

apt-get -y install build-essential libssl-dev git zlib1g-dev

apt-get -y install linux-headers-$(uname -r)

adduser builder
su builder
mkdir src
cd src
git clone https://github.com/domino-team/openwrt-cc.git
git clone https://github.com/ReFirmLabs/binwalk.git
cd binwalk
exit
// now back as root user
cd /home/builder/src/binwalk
deps.sh
python setup.py install
cd ..
wget https://www.wifipineapple.com/downloads/nano/2.0.2
mv 2.0.2 fw-nano2.0.2.bin
binwalk -e fw-nano2.0.2.bin
cd _fw-nano2.0.2.bin.extracted
rm  -rf squashfs-root/lib/modules/3.18.84/
rm -f squashfs-root/sbin/modprobe
cd ..
cp -r _fw-nano2.0.2.bin.extracted/squashfs-root  openwrt-cc/files
cd _
// dont use python3 they pythonextension
// aint working so welll like those with stdandard just python
chown -Rh builder:builder /home/builder/src
su builder
cd /home/builder/src/openwrt-cc/

CHANGE

nano feeds.conf.default

src-git packages https://github.com/openwrt/packages.git;for-15.05
TO
src-git packages https://github.com/adde88/packages.git
or uncomment with # at line beginning

echo „/dev/mtd1 0x0 0x10000 0x10000“ > files/etc/fw_env.config
touch files/etc/config/ubootenv
nano files/etc/config/ubootenv
insert:
config ubootenv
option dev ‚/dev/mtd1‘
option offset ‚0x0‘
option envsize ‚0x10000‘
option secsize ‚0x10000‘

PRESS CTRL + o
press y for yes save
PRESS CTRL + x
cd /home/builder/src
git clone https://github.com/adde88/openwrt-packages-community
cp -r openwrt-packages-community/network  openwrt-cc/packages/.
cp -r openwrt-packages-community/utils openwrt-cc/packages/.
cd openwrt-cc
./scripts/feeds update -a
./scripts/feeds install -a
make menuconfig
just select tooolchain
cat /proc/cpuinfo | grep processor | wc -l
// returns a number how many cores your machine got
// use this numvber at make jobe best is firast to :
make download -j$NUMBEROFCORES  -k -v V=sc 2>&1 | tee build.log
this will download nearly all sources also needed to rebuidl all
after this rerun it without download
make -j8 -k -v V=sc 2>&1 | tee build.log

if decivred install screen and alwasys aftert ssh connected to machin screen the seasion if the connection stucks down or just disconnected of any other reason you can reconnewct to screen seasion mad buidl process is astill running of the remote machine and you get the running process back with:
screnn -r