This repository has no description
machines.coaxmetal: Xbox pad pairing + gamepad-ready launcher session
Add strom-pair (in-session NoInputNoOutput agent + polling, bond check) to
pair Xbox Wireless Controllers one at a time, plus the bluez/kernel bits they
need: hardware.xpadneo, disable_ertm=1 (else AuthenticationFailed), and
FastConnectable=true so bonded pads reconnect. Point the launcher session at
evdev via SDL_JOYSTICK_HIDAPI_XBOX=0, poll hotplug with
SDL_JOYSTICK_DISABLE_UDEV=1, and allow input without focus via
SDL_JOYSTICK_ALLOW_BACKGROUND_EVENTS=1.
author
lassulus
date
(Jul 25, 2026, 11:28 PM CEST)
commit
93df609c
93df609c95c8f58d63bba747e9ad9d31623701ca
parent
ba556c34
ba556c349b85d2c62fb4b4c827917e96cb8cbd7c
+136
-1
+136
-1
machines/coaxmetal/strom.nix
+136
-1
machines/coaxmetal/strom.nix
···
11
11
# its closure stays tiny; games bring their own nested gamescope/proton.
12
12
strom-session = pkgs.writeShellScript "strom-session" ''
13
13
set -u
14
+
# xpadneo owns the Xbox pad's hidraw node, so force SDL (pygame launcher and
15
+
# the games) to read the pad through evdev instead of its HIDAPI backend -
16
+
# same fix as 2configs/steam.nix, without it SDL finds no controller.
17
+
export SDL_JOYSTICK_HIDAPI_XBOX=0
18
+
# SDL's udev-monitor hotplug does not deliver in this kiosk session, so a pad
19
+
# powered on after the launcher starts is never seen. Force SDL to poll
20
+
# /dev/input instead, which reliably picks up pads as they connect/disconnect.
21
+
export SDL_JOYSTICK_DISABLE_UDEV=1
22
+
# Under cage the launcher window never reports input focus, and SDL suppresses
23
+
# joystick (not keyboard) events while unfocused - so keyboard works but the
24
+
# pad does not. Allow joystick events regardless of focus.
25
+
export SDL_JOYSTICK_ALLOW_BACKGROUND_EVENTS=1
14
26
# Relaunch whenever the couch launcher exits (gamepad B / Esc) so the kiosk
15
27
# never drops to a blank tty. Keeping the loop as cage's child means the
16
28
# compositor stays up across relaunches.
···
19
31
sleep 2
20
32
done
21
33
'';
34
+
35
+
# Bluetooth pairing helper for Xbox Wireless Controllers. Run `strom-pair`
36
+
# once per controller (as root / on the console, e.g.
37
+
# `ssh root@coaxmetal.r strom-pair`): put the pad in pairing mode (hold the
38
+
# Xbox button to power on, then hold the small round sync button on the top
39
+
# edge until the light flashes rapidly) and the script blocks until it pairs
40
+
# that one fresh pad, then exits. Already-bonded pads are skipped, so just run
41
+
# it again for the next controller. Bonded+trusted pads reconnect on their own
42
+
# on every later boot. Pass a MAC (`strom-pair AA:BB:...`) to pair just one.
43
+
strom-pair = pkgs.writeShellApplication {
44
+
name = "strom-pair";
45
+
runtimeInputs = [ pkgs.bluez ];
46
+
text = ''
47
+
# Find one not-yet-bonded Xbox pad, echoing its MAC (empty if none). A
48
+
# foreground timed scan is reliable; a backgrounded `scan on` exits at once
49
+
# without a tty and never actually scans.
50
+
find_unpaired() {
51
+
local m
52
+
bluetoothctl --timeout 12 scan on >/dev/null 2>&1 || true
53
+
mapfile -t cand < <(bluetoothctl devices 2>/dev/null | grep -i xbox | awk '{print $2}')
54
+
for m in "''${cand[@]:-}"; do
55
+
[ -n "$m" ] || continue
56
+
bluetoothctl info "$m" 2>/dev/null | grep -q "Bonded: yes" && continue
57
+
printf '%s\n' "$m"
58
+
return 0
59
+
done
60
+
return 0
61
+
}
62
+
63
+
# Pair one pad. Xbox controllers use JustWorks pairing, which needs a
64
+
# NoInputNoOutput agent held in the SAME bluetoothctl session as `pair`
65
+
# (plus disable_ertm, set system-wide below). `connect` succeeds even when
66
+
# pairing fails, so success is judged by "Bonded: yes", not by connect.
67
+
pair_one() {
68
+
local mac="$1"
69
+
{
70
+
echo "power on"
71
+
echo "agent NoInputNoOutput"
72
+
echo "default-agent"
73
+
echo "scan on"
74
+
sleep 14
75
+
echo "pair $mac"
76
+
sleep 12
77
+
echo "trust $mac"
78
+
echo "connect $mac"
79
+
sleep 4
80
+
echo "quit"
81
+
} | bluetoothctl >/dev/null 2>&1 || true
82
+
# Bonding can finalize a moment after the session exits; poll a few
83
+
# seconds before deciding it failed.
84
+
for _ in 1 2 3 4 5; do
85
+
bluetoothctl info "$mac" 2>/dev/null | grep -q "Bonded: yes" && return 0
86
+
sleep 1
87
+
done
88
+
return 1
89
+
}
90
+
91
+
bluetoothctl power on >/dev/null 2>&1 || true
92
+
93
+
# Single-pad mode: pair exactly the given MAC and exit.
94
+
if [ -n "''${1:-}" ]; then
95
+
if pair_one "$1"; then
96
+
echo ">> paired, trusted, connected: $1"
97
+
exit 0
98
+
fi
99
+
echo "!! could not pair $1." >&2
100
+
exit 1
101
+
fi
102
+
103
+
# Default: wait for one fresh (unbonded) pad, pair it, then exit. Run once
104
+
# per controller; already-bonded pads are ignored so each run grabs the
105
+
# next one.
106
+
echo ">> put a controller in pairing mode: hold the Xbox button to power"
107
+
echo " on, then hold the small round sync button on the top edge until"
108
+
echo " the light flashes rapidly. Waiting... (Ctrl-C to abort)"
109
+
while true; do
110
+
echo ">> scanning..."
111
+
mac=$(find_unpaired)
112
+
# Show which Xbox pads are visible and whether they are already bonded,
113
+
# so it's obvious if the pad is being detected at all.
114
+
bluetoothctl devices 2>/dev/null | grep -i xbox | while read -r _ m _; do
115
+
if bluetoothctl info "$m" 2>/dev/null | grep -q "Bonded: yes"; then
116
+
echo " seen $m (already bonded, skipping)"
117
+
else
118
+
echo " seen $m (pairable)"
119
+
fi
120
+
done
121
+
if [ -n "$mac" ]; then
122
+
printf '>> pairing %s ... ' "$mac"
123
+
if pair_one "$mac"; then
124
+
echo "OK"
125
+
echo ">> paired, trusted, connected: $mac"
126
+
exit 0
127
+
fi
128
+
echo "failed, retrying (keep it in pairing mode)"
129
+
fi
130
+
sleep 1
131
+
done
132
+
'';
133
+
};
22
134
in
23
135
{
24
136
# Dedicated, unprivileged kiosk user. Gamepad input comes through evdev
···
55
167
# brightnessctl + its udev rules (chgrp backlight to the video group, g+w) so
56
168
# any video-group user (strom, lass) can adjust it without root, e.g.
57
169
# `brightnessctl set 100%` / `brightnessctl set 50%`.
58
-
environment.systemPackages = [ pkgs.brightnessctl ];
170
+
environment.systemPackages = [
171
+
pkgs.brightnessctl
172
+
strom-pair
173
+
];
59
174
services.udev.packages = [ pkgs.brightnessctl ];
60
175
61
176
# Force the backlight to maximum on every boot. Ordered after
···
67
182
Type = "oneshot";
68
183
ExecStart = "${pkgs.brightnessctl}/bin/brightnessctl set 100%";
69
184
};
185
+
};
186
+
187
+
# Xbox Wireless Controllers (Bluetooth). xpadneo for correct rumble/axis
188
+
# mapping; the two bluez tweaks + disable_ertm are what make Xbox pads
189
+
# actually bond (without disable_ertm they fail with AuthenticationFailed).
190
+
# Bluetooth itself (adapter + powerOnBoot) already comes from
191
+
# 2configs/pipewire.nix. Pair each pad once with `strom-pair` (see above).
192
+
hardware.xpadneo.enable = true;
193
+
# Xbox One/Series controllers pair over Bluetooth only with L2CAP ERTM off.
194
+
boot.extraModprobeConfig = "options bluetooth disable_ertm=1";
195
+
hardware.bluetooth.settings.General = {
196
+
# JustWorksRepairing lets bluez accept fresh pairings without a manual
197
+
# remove; Privacy = device pins a static host address so the controller's
198
+
# bond key survives RPA rotation.
199
+
JustWorksRepairing = "always";
200
+
Privacy = "device";
201
+
# Keep page scan always on so a bonded pad reconnects promptly when powered
202
+
# back on (otherwise bonded pads bond but never re-link). Fine on a
203
+
# mains-powered kiosk.
204
+
FastConnectable = true;
70
205
};
71
206
}