update new draft

content/posts/2023-08-20-dmrhost-on-openbsd-on-a-raspberry-pi-4/index.md

@@ -3,21 +3,220 @@
 title = 'DMRHost on OpenBSD on a Raspberry-Pi 4'
 summary = ''
 date = '2023-08-20T08:24:04+02:00'
-lastmod = '2023-08-20T08:13:37+0000'
+lastmod = '2023-08-20T09:15:14+0000'
 categories = [ 'amateur-radio' ]
 tags = [ 'hotspot', 'raspberry-pi', 'openbsd' ]
 
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 +++
 
+## Get the files
+
+Download `install73.img` from <https://www.openbsd.org/arm64.html> and
+write it to a USB stick.
+
+## Installation of OpenBSD
+
+Get yourself comfortable with this nice piece of documentation: [INSTALL.arm64][0]
+
+[0]: https://ftp.openbsd.org/pub/OpenBSD/snapshots/arm64/INSTALL.arm64
+
+Connect a USB-to-TTL cable to the GPIO pins of the serial console on your Raspberry Pi
+(That means you have to remove the MMDVM hat for now).
+
+```console
+$ cu -l /dev/cuaU0 -s 115200
+```
+
+To save you another manpage lookup, exit the serial console
+with <kbd>Enter</kbd>, <kbd>~.</kbd>.
+
+Boot the Raspberry Pi with no SD-Card plugged in but the USB stick.
+
+1. Stop the autoboot process at the bootloader by typing something at
+    the boot prompt (and delete the typed characters afterwards)
+
+2. Plugin the SD-Card and hit <kbd>Enter</kbd>
+
+3. The Installation media starts and detects your SD-Card
+
+4. Continue with the installation of OpenBSD
+
+We booted without SD-Card because I had problems selecting the USB media for booting.
+You can select this from within Raspbian OS but I did not want to install this in the
+first place.
+
+## System configuration
+
+Make sure to enable ssh. We will need that because we have to drop support for the
+serial console to use the MMDVM hat.
+
+## Disable the use of the serial console
+
+Modify `/etc/ttys` (only the first lines are relevant)
+
+```aconf {linenos=inline,hl_lines="6"}
+#
+#	$OpenBSD: ttys,v 1.2 2020/03/13 13:14:40 patrick Exp $
+#
+# name	getty				type	status		comments
+#
+console	"/usr/libexec/getty std.115200"	vt220	off secure
+ttyC0	"/usr/libexec/getty std.9600"	vt220	off secure
+ttyC1	"/usr/libexec/getty std.9600"	vt220	on  secure
+ttyC2	"/usr/libexec/getty std.9600"	vt220	on  secure
+```
+
+Change **on** to **off**. Now select the framebuffer device
+for your tty.
+
+```console
+$ echo "set tty fb0" | doas tee /etc/boot.conf
+```
+
+Once you made sure that you can login via ssh, turn off the Raspberry Pi and put on the
+MMDVM hat.
+
+Now you should be able to select `/dev/cua00` as the modem
+in your `MMDVM.ini`.
+
+## Setup DMRHost
+
+### Installation
+
+Get the files: <https://github.com/BrandMeister/DMRHost>.
+
+I prefer to use a separate user for this.
+
+```console
+$ doas useradd -L daemon -G dialer,users -m -d /home/mmdvm -s /sbin/nologin -c "Radio &" mmdvm
+```
+
+Now, let's create the DMRHost executable.
+
+```console
+$ cd /home/mmdvm
+$ doas -u mmdvm (mkdir git && cd git)
+$ doas -u mmdvm (git clone https://github.com/BrandMeister/DMRHost && cd DMRHost)
+$ doas -u mmdvm (mkdir build && cd build && cmake -DCMAKE_BUILD_TYPE=Release ..)
+$ doas -u mmdvm make && doas make install
+```
+
+**Note**: the last command is not executed as the user _mmdvm_
+but as _root_ as it is installing the executable into `/usr/local/bin`.
+Therefore we dropped the `-u mmdvm` on the last `doas` invocation!
+
+### Configuration of DMRHost: `MMDVM.ini`
+
+I use `/home/mmdvm/MMDVM.ini` because I'll put everything MMDVM-related
+into `/home/mmdvm`.
+
+The essential congiguration changes:
+
+```ini
+[...]
+
+[Log]
+# Logging levels, 0=No logging, 1=Debug, 2=Message, 3=Info, 4=Warning, 5=Error, 6=Fatal
+SyslogLevel=0
+DisplayLevel=0
+FileLevel=2
+FilePath=/home/mmdvm/logs
+FileRoot=DMRHost
+FileRotate=0
+
+[...]
+
+[Modem]
+Port=/dev/cua00
+Protocol=uart
+
+[...]
+```
+
+This is basically the same configuration as in the repository.
+Have a look at the `[Log]` section.
+
+### The rc script `/etc/rc.d/DMRHost`.
+
+```bash
+#!/bin/sh
+
+DMRHOST="/usr/local/bin/DMRHost"
+MMDVM_INI="/home/mmdvm/MMDVM.ini"
+DMRHOST_PID="/home/mmdvm/DMRHost.pid"
+DOAS="/usr/bin/doas -u mmdvm"
+LOGDIR="/home/mmdvm/logs"
+
+case "$1" in
+  "start")
+    if [ ! -d ${LOGDIR} ] ; then
+      mkdir ${LOGDIR}
+      chown mmdvm:users ${LOGDIR}
+      chmod 0775 ${LOGDIR}
+    fi
+    if ${DOAS} [ ! -r ${MMDVM_INI} ] ; then
+      echo "${MMDVM_INI} is not readable... aborting!"
+      exit 1
+    fi
+    echo "Starting DMRHost..."
+    ${DOAS} ${DMRHOST} ${MMDVM_INI} &
+    echo $! > ${DMRHOST_PID}
+    echo "done"
+  ;;
+
+  "stop")
+    echo "Stopping DMRHost..."
+    if [ -f ${DMRHOST_PID} ] ; then
+      kill `cat ${DMRHOST_PID}`
+      rm -f ${DMRHOST_PID}
+      echo "done"
+    else
+      echo "not running?"
+    fi
+  ;;
+
+  "restart")
+    echo "Restarting DMRHost..."
+    $0 stop
+    sleep 2
+    $0 start
+  ;;
+
+  *)
+    echo "$0 [start|stop|restart]"
+  ;;
+
+esac
+```
+
+### First test / first start
+
+Start DMRHost (not the service)
+
+```console
+$ doas -u mmdvm /usr/local/bin/DMRHost /home/mmdvm/MMDVM.ini
+```
+
+and see what it does. If it's logging into the master,
+all is good and can be stopped with <kbd>CTRL</kbd>+<kbd>C</kbd>.
+
+### Enable and start the service
+
+```console
+$ doas rcctl enable DMRHost
+$ doas rcctl start DMRHost
+```
+
+DMRHost runs.
+
+## Some additional notes
+
+I put myself (another user on the Raspberry Pi) into
+the _users_ group and chmod the `MMDVM.ini` with with 664.
+
+That allows me to edit the file as my usual user and I do
+**not** have to use `doas -u mmdvm` everytime I want to
+modify something in that file.