autoconf: xen: move standard path variables to config/Paths.mk.in
This moves all generic path variables to a new the config/Paths.mk.in
input source file to be processed at configure time, tons of files use
these so this just share them. This also paves the way to let us
easily dynamically configure these with autoconf, for now we leave the
same presets as was present before.
This work was prompted by looking for an autoconf way to do
replacements for the hotplug global file, while at it I realized
that a few other files use the same variables and have in places
around the tree the same constructs for generating their own
files. This makes use of the old buildmakevars2file() but generalizes
the definition of the paths at configure time and spreads the
new definitions out throughout the build system.
This has no impact on building the hypervisor and extras/mini-os,
you do not need to, and are not expected to, run configure to build
those targets.
While at it lets add some documentation on the for the two files on
the source file, we can expand further details on the wiki [0].
[0] http://wiki.xen.org/wiki/Category:Host_Configuration#System_wide_xen_configuration
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Keir Fraser <keir@xen.org>
Cc: Tim Deegan <tim@xen.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[ ijc -- reran autogen.sh ]