Dump1090-fa fails to start after rtl_biast is enabled

FlightAware ADS-B Flight Tracking
1

Hello!
I am using the current piaware image (downloaded 4/6/25) everything is working fine when I start dump1090-fa and rtl_biast separately, but as soon as I try to enable it to automatically start on boot I get the following error:

░░ The job identifier is 2129 and the job result is done.
Apr 07 19:54:30 piaware (tl_biast)[1040]: dump1090-fa.service: Failed to execute /home/pi/rtl_biast/build/src/rtl_biast: Permission denied
Apr 07 19:54:30 piaware (tl_biast)[1040]: dump1090-fa.service: Failed at step EXEC spawning /home/pi/rtl_biast/build/src/rtl_biast: Permission denied
░░ Subject: Process /home/pi/rtl_biast/build/src/rtl_biast could not be executed
░░ Defined-By: systemd

Permissions:
drwxr-xr-x 3 pi pi 4096 Apr 7 20:11 src
-rwxr-xr-x 1 pi pi 18288 Apr 7 20:11 rtl_biast

I used the following steps to install rtl_biast:
cd ~
git clone https://github.com/rtlsdrblog/rtl_biast
cd rtl_biast
mkdir build
cd build
cmake .. -DDETACH_KERNEL_DRIVER=ON
make

Tested with this command and it worked fine:
sudo service dump1090-fa stop && cd ~/rtl_biast/build/src && ./rtl_biast -b 1 && sudo service dump1090-fa start

Added this:
sudo mkdir /etc/systemd/system/dump1090-fa.service.d
sudo nano /etc/systemd/system/dump1090-fa.service.d/bias-t.conf

Then added in the following:
[Service]
ExecStartPre=/home/pi/rtl_biast/build/src/rtl_biast -b 1

After reboot I get the above mentioned error.

So I reverted back to manually running dump1090-fa and enabling RTL-BIAST with this command until we can figure it out:
sudo service dump1090-fa stop && cd ~/rtl_biast/build/src && ./rtl_biast -b 1 && sudo service dump1090-fa start

The result is:
pi@piaware:~/rtl_biast/build $ sudo service dump1090-fa stop && cd ~/rtl_biast/build/src && ./rtl_biast -b 1 && sudo service dump1090-fa start
Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00000001

Using device 0: Generic RTL2832U OEM
Found Rafael Micro R820T tuner

Any ideas?

Thank you,
Marek

1 Like
2

Rats, must be really simple or a really tough question :slight_smile:

1 Like
3

I’ve stopped answering linux related questions for people who don’t really care to learn linux.

Instead i’m contributing to make this image better: https://discussions.flightaware.com/t/a-simple-way-to-feed-ads-b-data/90183

That way people who don’t want to learn linux don’t have to.

2 Likes
4

Fair answer and I figured it was an easy question :slight_smile:

I know it relates to permissions, but I will look at the ADSB Feeder Image if I can’t figure it out.

Thanks!

5

dump1090-fa service runs as user dump1090 i believe?
/home/pi is not accessible for other non-root users.

Thus the perms of the actual files don’t matter if X is not set for a parent directory.

1 Like
6

I’ve now set chmod o+x on the /home/pi and rebooted.

I don’t recall doing that in the past, but that did seem to fix the problem.

Thank you for the pointer, help much appreciated. I will go ahead and build another pi with the image you currently actively contribute to and see how that works as well.

1 Like