pkg-*.mk: add some comments, update some existing comments

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/pkg-autotargets.mk

@@ -3,9 +3,7 @@
 #
 # This file implements an infrastructure that eases development of
 # package .mk files for autotools packages. It should be used for all
-# packages that use the autotools as their build system. Non-autotools
-# packages should use the generic infrastructure in
-# package/Makefile.package.in.
+# packages that use the autotools as their build system.
 #
 # See the Buildroot documentation for details on the usage of this
 # infrastructure

package/pkg-download.mk

@@ -1,3 +1,12 @@
+############################################################################
+#
+# This file contains the download helpers for the various package
+# infrastructures. It is used to handle downloads from HTTP servers,
+# FTP servers, Git repositories, Subversion repositories, Mercurial
+# repositories, Bazaar repositories, and SCP servers.
+#
+############################################################################
+
 # Download method commands
 WGET:=$(call qstrip,$(BR2_WGET)) $(QUIET)
 SVN:=$(call qstrip,$(BR2_SVN))

package/pkg-gentargets.mk

@@ -2,9 +2,10 @@
 # Generic package infrastructure
 #
 # This file implements an infrastructure that eases development of
-# package .mk files. It should be used for all non-autotools based
-# packages. Autotools-based packages should use the specialized
-# autotools infrastructure in package/Makefile.autotools.in.
+# package .mk files. It should be used for packages that do not rely
+# on a well-known build system for which Buildroot has a dedicated
+# infrastructure (so far, Buildroot has special support for
+# autotools-based and CMake-based packages).
 #
 # See the Buildroot documentation for details on the usage of this
 # infrastructure
@@ -17,9 +18,6 @@
 #
 #   2. Description of the commands to be executed to configure, build
 #      and install the package
-#
-# The autotools infrastructure specializes this generic infrastructure
-# by already implementing the configure, build and install steps.
 ################################################################################
 
 ################################################################################

package/pkg-utils.mk

@@ -1,3 +1,10 @@
+############################################################################
+#
+# This file contains various utility functions used by the package
+# infrastructure, or by the packages themselves.
+#
+############################################################################
+
 # UPPERCASE Macro -- transform its argument to uppercase and replace dots and
 # hyphens to underscores
 
@@ -16,6 +23,12 @@ UPPERCASE = $(strip $(eval __tmp := $1) \
 			$(__tmp)))) \
      $(__tmp))
 
+#
+# Manipulation of .config files based on the Kconfig
+# infrastructure. Used by the Busybox package, the Linux kernel
+# package, and more.
+#
+
 define KCONFIG_ENABLE_OPT
        $(SED) "/\\<$(1)\\>/d" $(2)
        echo "$(1)=y" >> $(2)