I'm writing this since it could be helpful to everyone trying to make the DVBSky T982 DVB-C card work on a V1000 Synology running DSM 7 and above.

Specs:

• Model: Synology DS1821+
• Arch: x86_64
• Core Name: v1000
• OS: DSM 7.3.2-86009 Update 1
• Linux Kernel 4.4.302+
• The PCI-DVB device I'm using is a DVBSky T982 PCIe card
  • This device is reported to be supported inside the Linux Kernel from 3.19, but the required modules are not provided by DSM kernel. So, we'll have to compile the kernel modules ourselves.

This guide will use the media_build repo from Linuxtv to compile the kernel modules. This repo backports patches to use more recent devices in legacy kernels. This repo is EOL, but it should work for a myriad of devices, and there are no other alternatives to my knowledge.

This is a fork of the Embedded-MediaDrivers repo by @b-rad-NDi. I simply added support for the V1000 architecture.

I combined it with the information by @belgio99 in his dsm7-dvb-drivers repository.

Further, I want to thank @th0ma7 for the work on his Synology repo.

They all made my life so much easier for compiling and installing the kernel modules with the Synology toolchain. I used their work as a base for this guide.

I cannot, and will not, be held responsible for any damage to your Synology.

Moreover, this guide is provided as-is: I can't guarantee that it will work for other architectures, in fact it's known that there are architectures that have problems with compiling the kernel modules.

I'm just sharing what worked for me and my v1000 architecture.

• A Synology v1000 architecture NAS with DSM 7 installed
• A DVB device supported by the Linux Kernel (check here for reference)

First of all, we need to prepare the build environment. I chose to do everything in a Docker container, to keep my system clean and tidy.

So I spun up an Ubuntu 22.04 container:

root@NAS# docker run -it --platform linux/amd64 --name dsm7-dvb-build ubuntu:latest bash

Now update and install the required packages:

root@BUILD_ENV# apt update
root@BUILD_ENV# apt install build-essential ncurses-dev bc libssl-dev libc6-i386 curl libproc-processtable-perl git wget kmod patchutils

Then, create a folder with all the tools needed for the compilation:

root@BUILD_ENV# mkdir /compile
root@BUILD_ENV# cd /compile
root@BUILD_ENV# git clone https://github.com/Snafu/Embedded-MediaDrivers
root@BUILD_ENV# cd Embedded-MediaDrivers

This will clone this Embedded-MediaDrivers repo, which contains the tool you'll use to compile the kernel modules.

The toolchain and GPL sources are downloded automatically when configuring for V1000 archtitecture. You simply need to change the variables KERNEL_URI and TOOLCHAIN_URI in the beginning of configs/SYNO-V1000.conf.

Look for the latest toolchain (filname starting with v1000-gcc) in the subfolder of the DSM version you want to buid for: https://archive.synology.com/download/ToolChain/toolchain Copy the link to the file and set the variable TOOLCHAIN_URI to that value.

Look for the GPL sources (filename starting with linux-) in the subfolder of the DSM version you want to buid for: https://archive.synology.com/download/ToolChain/Synology%20NAS%20GPL%20Source To find the required version run uname -r first. In my case I needed linux-4.4.x.txz. Copy the link to the file and set the variable KERNEL_URI to that value.

Run the following command:

root@BUILD_ENV# ./md_builder.sh -g -b -d SYNO-V1000

to compile the Synology kernel and media modules. This takes a while. The script automatically checks out the latest working commit and applies a required patch.

To get the modules onto your NAS, exit the shell of the docker container to return to your NAS shell and run the following:

root@BUILD_ENV# exit
root@NAS# [ ! -e /sbin/depmod ] && ln -s /usr/bin/kmod /sbin/depmod
root@NAS# cd /lib/modules && docker exec -i dsm7-dvb-build /bin/bash -c "cd /lib/modules/$(uname -r)/kernel; tar -cf - drivers" | tar -xvf -
root@NAS# cd /lib/modules && depmod -a

This copies the modules from the build environment to /lib/modules/drivers using tar as a middleman. Finally it runs depmod to create the dependency files required by modprobe.

Create the file /usr/local/etc/rc.d/load-modules.sh to load the kernel modules at startup, then restart your NAS.

#!/bin/sh

case $1 in
start)
        echo "Loading DVB core module"
        modprobe dvb-core
        modprobe cx23885
        ;;
        stop)
        # nothing
        ;;
        *)
        echo "Usage: $0 {start|stop}"
        exit 1
        ;;
esac

exit 0

In my case, I also needed to load the firmware for my device. In fact, dmesg was reporting the following errors:

root@NAS# dmesg
...
[ 8894.387635] cx23885: cx23885 driver version 0.0.4 loaded
[ 8894.393089] cx23885: CORE cx23885[0]: subsystem: 4254:0982, board: DVBSky T982 [card=51,autodetected]
[ 8894.635070] cx25840 4-0044: cx23885 A/V decoder found @ 0x88 (cx23885[0])
[ 8894.652196] cx25840 4-0044: Direct firmware load for v4l-cx23885-avcore-01.fw failed with error -2
[ 8894.661165] cx25840 4-0044: Falling back to user helper
[ 8894.670330] cx25840 4-0044: unable to open firmware v4l-cx23885-avcore-01.fw
...
[ 9313.418992] si2168 2-0064: Direct firmware load for dvb-demod-si2168-b40-01.fw failed with error -2
[ 9313.428067] si2168 2-0064: Falling back to user helper
[ 9313.436502] si2168 2-0064: firmware file 'dvb-demod-si2168-b40-01.fw' not found
[ 9313.454274] si2157 6-0060: found a 'Silicon Labs Si2157-A30 ROM 0x50'
[ 9313.460753] si2157 6-0060: Direct firmware load for dvb_driver_si2157_rom50.fw failed with error -2
[ 9315.985046] si2157 6-0060: Falling back to user helper
...

This was due to missing firmware: I downloaded the correct firmwares from the CoreELEC repo and the linux-firmware.txz file from Synology Archive Download Site and put it in the /lib/firmware folder of my NAS. For my device, I needed the firmware files dvb-tuner-si2157-a30-01.fw and dvb-demod-si2168-b40-01.fwfrom the CoreELEC repo, whereby I had to rename dvb-tuner-si2157-a30-01.fw to dvb_driver_si2157_rom50.fw to make it work. In addition I needed the file v4l-cx23885-avcore-01.fw from the Synology linux-firmware.txz.

To me, this "unsupported" device is now working flawlessly. I'm using it with a TVHeadend docker container from linuxserver.io. I had to alter the container config file manually to add the /dev/dvb/adapterX/frontent0 et al device files to the container, after creating it using the ContainerManager Synology app. There is also a SynoCommunity package, however, I never tested that.