when systemd is used : (files are found in /etc/systemd/system being links to the real files in /lib/systemd/system/ )
First you alter mmdvmhost.service by adding the 'Requires' line This will tell the service it needs nextiondriver.service before starting MMDVMHost.
mmdvmhost.service
[Unit]
Description=MMDVM Host Service
After=syslog.target network.target
Requires=nextiondriver.service
[Service]
User=root
WorkingDirectory=/opt/MMDVMHost
ExecStartPre=/bin/sleep 3
ExecStart=/usr/bin/screen -S MMDVMHost -D -m /opt/MMDVMHost/MMDVMHost /opt/MMDVM.ini
ExecStop=/usr/bin/screen -S MMDVMHost -X quit
[Install]
WantedBy=multi-user.target
Then you make a service 'nextiondriver.service' where you tell it needs to start before MMDVMHost :
nextiondriver.service
[Unit]
Description=NextionDriver service
DefaultDependencies=no
After=local-fs.target wifi-country.service
Before=timers.target
[Service]
User=root
WorkingDirectory=/opt/MMDVMHost
Type=forking
ExecStart=/opt/NextionDriver/NextionDriver -i -c /opt/MMDVM.ini -vvvv
ExecStop=/usr/bin/killall NextionDriver
[Install]
WantedBy=multi-user.target
WantedBy=network-online.target
RequiredBy=mmdvmhost.service