Here is an interesting article on MicroCore Linux,I haven't tried it on,can be useful though.
1. Start Microcore with Qemu
After boot you should see a prompt.
2. Check if openssh extension is installed
If you can't see the files above you should get them first. Run this command in terminal:
tc-load -w openssh
Make openssh extension being loaded during the boot of Microcore Linux:
echo "openssh.tcz" >> /mnt/hda1/tce/onboot.lst
3. Start openssh daemon (as a root)
You can see is an error message about missing sshd-config configuration file. So we need to create it.
mv /usr/local/etc/ssh/sshd_config.example /usr/local/etc/ssh/sshd_config
If you don't edit sshd_config file all the uncomment lines are used by default by opennssh deamon . Now we may run openssh again.
First time you successfully start openssh daemon, the public/private rsa key pair and public/private dsa key are generated.
4. Automatic start openssh deamon after boot of Microcore
echo "/usr/local/etc/init.d/openssh start" >> /opt/bootlocal.sh
5. Backup of configuration directory "/usr/local/etc/ssh"
echo "/usr/local/etc/ssh" >> /opt/.filetool.lst
6. Test ssh server (password is root)
You should be able to login now.