README
1
2 Introduction
3
4The following readme are cuts from the linux-hotplug-devel mailing list announcement.
5http://marc.theaimsgroup.com/?l=linux-hotplug-devel&m=115720744227751&w=2
6
7--
8Hotplug2 is aimed at early Linux user space, that is, initramfs or initrd,
9possibly also at embedded devices (such as WRT-like routers) or very weak
10machines, such as 386/486 (some still use them as workstations).
11
12Hotplug2 connects to the uevent netlink socket and read events. The
13application generally operates in two modes, dumb and smart.
14
15In dumb mode, when event arrives, we generally only check if it has MODALIAS
16set; if yes, we spawn modprobe and carry on.
17
18In smart mode, simple form of rules are applied. Those rules allow matching of
19the variables obtained by the uevent socket and allows execution of
20applications, with those variables set as their environmental variables.
21Further documentation of rules syntax is available at the homepage of the
22project.
23
24Hotplug2 supports cold plugging simply by calling the 'udevtrigger' binary
25internally. As udevtrigger is fairly independent on the rest of udev, it can be
26easily embedded along with Hotplug2. Given that Hotplug2 is in it's infancy,
27this can be considered a minor detail and replaced some time later.
28
29The advantages over udev are, as I believe:
30 * Faster (way faster!) processing of events, because far less actions are
31performed.
32 * The size is (obviously) also way smaller, which is a generic advantage;)
33
34The disadvantages would be:
35 * Far less actions are performed and far less actions _can_ be performed.
36
37Therefore, as said earlier, Hotplug2 definitely is not aimed as replacement
38for udev on desktop, with the exception of initramfs / initrd.
39---
40
41To enable debugging, compile with -DDEBUG.
42