NixOS on ARM/Raspberry Pi 4: Difference between revisions
imported>Fuu0 m removed unrelated config, updated infos based on a long debugging session... |
imported>Valodim add some usage info on HDMI-CEC |
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</nowiki>}} | </nowiki>}} | ||
=== HDMI-CEC === | |||
A few bits and pieces for using HDMI-CEC on the Pi4: | |||
{{file|/etc/nixos/configuration.nix|nix|<nowiki> | |||
{ pkgs, ... }: | |||
{ | |||
# an overlay to enable raspberrypi support in libcec, and thus cec-client | |||
nixpkgs.overlays = [ | |||
(self: super: { libcec = super.libcec.override { inherit (self) libraspberrypi; }; }) | |||
]; | |||
# install libcec, which includes cec-client (requires root or "video" group, see udev rule below) | |||
# scan for devices: `echo 'scan' | cec-client -s -d 1` | |||
# set pi as active source: `echo 'as' | cec-client -s -d 1` | |||
environment.systemPackages = with pkgs; [ | |||
libcec | |||
]; | |||
services.udev.extraRules = '' | |||
# allow access to raspi cec device for video group (and optionally register it as a systemd device, used below) | |||
SUBSYSTEM=="vchiq", GROUP="video", MODE="0660", TAG+="systemd" | |||
''; | |||
# optional: attach a persisted cec-client to `/run/cec.fifo`, to avoid the CEC ~1s startup delay per command | |||
# scan for devices: `echo 'scan' > /run/cec.fifo ; journalctl -u cec-client.service` | |||
# set pi as active source: `echo 'as' > /run/cec.fifo` | |||
systemd.sockets."cec-client" = { | |||
after = [ "sys-devices-platform-soc-fe00b840.mailbox-vchiq-vchiq.device" ]; | |||
bindsTo = [ "sys-devices-platform-soc-fe00b840.mailbox-vchiq-vchiq.device" ]; | |||
wantedBy = [ "sockets.target" ]; | |||
socketConfig = { | |||
ListenFIFO = "/run/cec.fifo"; | |||
SocketGroup = "video"; | |||
SocketMode = "0660"; | |||
}; | |||
}; | |||
systemd.services."cec-client" = { | |||
after = [ "sys-devices-platform-soc-fe00b840.mailbox-vchiq-vchiq.device" ]; | |||
bindsTo = [ "sys-devices-platform-soc-fe00b840.mailbox-vchiq-vchiq.device" ]; | |||
wantedBy = [ "multi-user.target" ]; | |||
serviceConfig = { | |||
ExecStart = ''${pkgs.libcec}/bin/cec-client -d 1''; | |||
ExecStop = ''/bin/sh -c "echo q > /run/cec.fifo"''; | |||
StandardInput = "socket"; | |||
StandardOutput = "journal"; | |||
Restart="no"; | |||
}; | |||
} | |||
</nowiki>}} | |||
== Notes about the boot process == | == Notes about the boot process == | ||