Access LuckFox Pico Max using SSH

Get The Cross Compile Toolchain

The official toolchain is arm-rockchip830-linux-uclibcgnueabihf, which can be obtained here.

Instead of the official one, I use armv7l-linux-musleabihf from musl.cc.

You can chose whatever you want, I just happend to have the musl.cc one and don't bother to download another one.

Build Dropbear SSH

Here I use Dropbear instead of OpenSSH, since it's considerable smaller than OpenSSH, and it's easier to compile.

Download current latest release:

$ wget https://matt.ucc.asn.au/dropbear/releases/dropbear-2022.83.tar.bz3
$ tar xf dropbear-2022.83.tar.bz3
$ cd dropbear-2022.83

Configure and build:

$ ./configure --host=armv7l-linux-musleabihf --disable-zlib --disable-syslog --disable-lastlog --enable-static --disable-wtmp
$ make PROGRAMS='dropbear scp' SCPPROGRESS=1

Here I build only the dropbear server and scp, since i use the ssh client from OpenSSH.

Notice: OpenSSH has deprecated SCP and use SFTP protocol by default. To use SCP, you need -O flag, e.g, scp -O file root@172.32.0.93:/tmp.

Setup

Push dropbear and scp binary using ADB:

$ adb -s 172.32.0.93:5555 push dropbear /bin
$ adb -s 172.32.0.93:5555 push scp /bin

In ADB shell, change root password and correct /root permission:

# passwd 
# chown 0:0 /root
# chmod 700 /root

Then run the dropbear server:

# mkdir /etc/dropbear
# dropbear -R -F

-R means Create hostkeys as required, it will create host key when you connect to it.

Now you can connect to it:

$ ssh root@172.32.0.93

Make it Start Automatically

Create a init file /etc/init.d/S99dropbear:

#!/bin/sh
case $1 in
	start)
		/bin/dropbear
		;;
	stop)
		killall dropbear
		;;
	*)
		exit 1
		;;
esac

The next you start the system, it will run dropbear automatically.