cmake: add documentation about how it is built

Commit 7b17bafc5d by Davide Viti has a
detailed explanation of some unusual techniques used for building
host-cmake and (target-)cmake. This is useful information for whoever
starts hacking on it, so copy it in the makefile, where it will be
easily noticed.

Also remove the sentence about host-cmake having a runtime dependency
on host-pkgconfig (not true anymore: it's the specific cmake-packages
that depend on it) and fix typos.

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Cc: Samuel Martin <s.martin49@gmail.com>
Cc: Davide Viti <zinosat@tiscali.it>
Cc: Arnout Vandecappelle <arnout@mind.be>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
This commit is contained in:
Luca Ceresoli 2016-07-01 17:53:29 +02:00 committed by Thomas Petazzoni
parent 6ab3383f76
commit fc832dd126

View File

@ -10,6 +10,18 @@ CMAKE_SITE = https://cmake.org/files/v$(CMAKE_VERSION_MAJOR)
CMAKE_LICENSE = BSD-3c
CMAKE_LICENSE_FILES = Copyright.txt
# CMake is a particular package:
# * CMake can be built using the generic infrastructure or the cmake one.
# Since Buildroot has no requirement regarding the host system cmake
# program presence, it uses the generic infrastructure to build the
# host-cmake package, then the (target-)cmake package can be built
# using the cmake infrastructure;
# * CMake bundles its dependencies within its sources. This is the
# reason why the host-cmake package has no dependencies:, whereas
# the (target-)cmake package has a lot of dependencies, using only
# the system-wide libraries instead of rebuilding and statically
# linking with the ones bundled into the CMake sources.
CMAKE_DEPENDENCIES = zlib jsoncpp libcurl libarchive expat bzip2 xz
CMAKE_CONF_OPTS = \