units: add usb-gadget target

Linux can be run on a device meant to act as a USB peripheral. In order
for a machine to act as such a USB device it has to be equipped with
a UDC - USB Device Controller.

This patch adds a target reached when UDC becomes available. It can be used
for activating e.g. a service unit which composes a USB gadget with
configfs and activates it.
This commit is contained in:
Andrzej Pietrasiewicz 2019-01-29 11:13:44 +01:00 committed by Lennart Poettering
parent 791cd15993
commit 2c633a821e
3 changed files with 25 additions and 0 deletions

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@ -83,6 +83,7 @@
<filename>time-sync.target</filename>,
<filename>timers.target</filename>,
<filename>umount.target</filename>,
<filename>usb-gadget.target</filename>,
<!-- slices --><filename>-.slice</filename>,
<filename>system.slice</filename>,
<filename>user.slice</filename>,
@ -799,6 +800,16 @@
dynamically when audio hardware is found.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><filename>usb-gadget.target</filename></term>
<listitem>
<para>This target is started automatically as soon as a
USB Device Controller becomes available at boot.</para>
<para>This may be used to pull in usb gadget
dynamically when UDC hardware is found.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>

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@ -56,6 +56,8 @@ SUBSYSTEM=="printer", TAG+="systemd", ENV{SYSTEMD_WANTS}+="printer.target"
SUBSYSTEM=="usb", KERNEL=="lp*", TAG+="systemd", ENV{SYSTEMD_WANTS}+="printer.target"
SUBSYSTEM=="usb", ENV{DEVTYPE}=="usb_device", ENV{ID_USB_INTERFACES}=="*:0701??:*", TAG+="systemd", ENV{SYSTEMD_WANTS}+="printer.target"
SUBSYSTEM=="udc", ACTION=="add", TAG+="systemd", ENV{SYSTEMD_WANTS}+="usb-gadget.target"
# Apply sysctl variables to network devices (and only to those) as they appear.
ACTION=="add", SUBSYSTEM=="net", KERNEL!="lo", RUN+="@rootlibexecdir@/systemd-sysctl --prefix=/net/ipv4/conf/$name --prefix=/net/ipv4/neigh/$name --prefix=/net/ipv6/conf/$name --prefix=/net/ipv6/neigh/$name"

12
units/usb-gadget.target Normal file
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@ -0,0 +1,12 @@
# SPDX-License-Identifier: LGPL-2.1+
#
# This file is part of systemd.
#
# systemd is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
[Unit]
Description=Hardware activated USB gadget
Documentation=man:systemd.special(7)