Re: [gentoo-dev] About udev-145: new features / extras and kernel requirements

[Bruno]

On Sun, 30 August 2009 Matthias Schwarzott <zzam@g.o> wrote:
> The new udev-145 and newer have some new kernel requirements. How
> should the ebuild verify they are met?
> Some possible ways:
> 1. Check config under /usr/src/linux

/usr/src/linux is not the best place to look at...

Checks should rather be done on first kernel config found in following
locations (checked in this order):
 - KBUILD_OUTPUT
 - KERNEL_DIR
 - /usr/src/linux, /proc/config.gz, /lib/modules/$(uname -r)/build/.config

Maybe just use linux-info eclass for the checks

> 2. Check /proc/config.gz

This should rather happen in init script, if possible do not check
on every boot but only when a "new" kernel is used (e.g. when uname
output changes)

> 3. Print message for user in pkg_postinst

This makes sense in any case.

> Second point: udev-145 bundles a lot of new extras, but they can only
> be enabled/disabled all or nothing.
>
> These extras are:
> * udev-acl: Apply consolekit permissions to devices for users (audio,
> video, joysticks, scanner, cameras, ...)

Is this bound to consolekit or does it rather fall under 'acl' use-flag?
I guess this includes a kernel requirement (ACL support for tmpfs)

> * usb-db: Provide udev-rules with device names of pci and usb devices
> * hid2hci: Special utility to fix resume of some hid devices
> * keymap: Auto-configure model specific keys found on many laptops
> ("brightness up", "next song", "www browser", or "suspend")
> * modem-modeswitch: Switch modems that provide virtual cd-drive with
> drivers to modem mode
> * gudev: glib/gobject support for libudev

Is gudev just a binding or is it more? If it's just a binding it may
be nice to have it tied to a use-flag.

> This makes udev depend on these libs:
> libacl, libglib2, libusb, usbutils, pciutils, gperf

Bruno