Bump buidlroot version to 2018.02.6

bsp/buildroot/docs/manual/adding-packages-generic.txt

@@ -22,7 +22,7 @@ system is based on hand-written Makefiles or shell scripts.
 07: LIBFOO_VERSION = 1.0
 08: LIBFOO_SOURCE = libfoo-$(LIBFOO_VERSION).tar.gz
 09: LIBFOO_SITE = http://www.foosoftware.org/download
-10: LIBFOO_LICENSE = GPLv3+
+10: LIBFOO_LICENSE = GPL-3.0+
 11: LIBFOO_LICENSE_FILES = COPYING
 12: LIBFOO_INSTALL_STAGING = YES
 13: LIBFOO_CONFIG_SCRIPTS = libfoo-config
@@ -197,12 +197,25 @@ information is (assuming the package name is +libfoo+) :
 * +LIBFOO_VERSION+, mandatory, must contain the version of the
   package. Note that if +HOST_LIBFOO_VERSION+ doesn't exist, it is
   assumed to be the same as +LIBFOO_VERSION+. It can also be a
-  revision number, branch or tag for packages that are fetched
-  directly from their revision control system. +
-  Examples: +
-    +LIBFOO_VERSION = 0.1.2+ +
-    +LIBFOO_VERSION = cb9d6aa9429e838f0e54faa3d455bcbab5eef057+ +
-    +LIBFOO_VERSION = stable+
+  revision number or a tag for packages that are fetched directly
+  from their version control system. Examples:
+  ** a version for a release tarball: +LIBFOO_VERSION = 0.1.2+
+  ** a sha1 for a git tree: +LIBFOO_VERSION = cb9d6aa9429e838f0e54faa3d455bcbab5eef057+
+  ** a tag for a git tree +LIBFOO_VERSION = v0.1.2+
++
+.Note:
+Using a branch name as +FOO_VERSION+ is not supported, because it does
+not and can not work as people would expect it should:
++
+  1. due to local caching, Buildroot will not re-fetch the repository,
+     so people who expect to be able to follow the remote repository
+     would be quite surprised and disappointed;
+  2. because two builds can never be perfectly simultaneous, and because
+     the remote repository may get new commits on the branch anytime,
+     two users, using the same Buildroot tree and building the same
+     configuration, may get different source, thus rendering the build
+     non reproducible, and people would be quite surprised and
+     disappointed.
 
 * +LIBFOO_SOURCE+ may contain the name of the tarball of the package,
   which Buildroot will use to download the tarball from
@@ -263,7 +276,7 @@ information is (assuming the package name is +libfoo+) :
   the file using this URL. Otherwise, Buildroot will assume the file
   to be downloaded is located at +LIBFOO_SITE+. Buildroot will not do
   anything with those additional files, except download them: it will
-  be up to the package recipe to use them from +$(BR2_DL_DIR)+.
+  be up to the package recipe to use them from +$(DL_DIR)+.
 
 * +LIBFOO_SITE_METHOD+ determines the method used to fetch or copy the
   package source code. In many cases, Buildroot guesses the method
@@ -399,8 +412,8 @@ information is (assuming the package name is +libfoo+) :
 * +LIBFOO_LICENSE+ defines the license (or licenses) under which the package
   is released.
   This name will appear in the manifest file produced by +make legal-info+.
-  If the license appears in xref:legal-info-list-licenses[the following list],
-  use the same string to make the manifest file uniform.
+  If the license appears in https://spdx.org/licenses/[the SPDX License List],
+  use the SPDX short identifier to make the manifest file uniform.
   Otherwise, describe the license in a precise and concise way, avoiding
   ambiguous names such as +BSD+ which actually name a family of licenses.
   This variable is optional. If it is not defined, +unknown+ will appear in
@@ -408,12 +421,12 @@ information is (assuming the package name is +libfoo+) :
   The expected format for this variable must comply with the following rules:
   ** If different parts of the package are released under different
   licenses, then +comma+ separate licenses (e.g. +`LIBFOO_LICENSE =
-  GPLv2+, LGPLv2.1+`+). If there is clear distinction between which
+  GPL-2.0+, LGPL-2.1+`+). If there is clear distinction between which
   component is licensed under what license, then annotate the license
   with that component, between parenthesis (e.g. +`LIBFOO_LICENSE =
-  GPLv2+ (programs), LGPLv2.1+ (libraries)`+).
+  GPL-2.0+ (programs), LGPL-2.1+ (libraries)`+).
   ** If the package is dual licensed, then separate licenses with the
-  +or+ keyword (e.g. +`LIBFOO_LICENSE = AFLv2.1 or GPLv2+`+).
+  +or+ keyword (e.g. +`LIBFOO_LICENSE = AFL-2.1 or GPL-2.0+`+).
 
 * +LIBFOO_LICENSE_FILES+ is a space-separated list of files in the package
   tarball that contain the license(s) under which the package is released.
@@ -453,6 +466,13 @@ information is (assuming the package name is +libfoo+) :
   FLAT binary format is only 4k bytes. If the application consumes more stack,
   append the required number here.
 
+* +LIBFOO_BIN_ARCH_EXCLUDE+ is a space-separated list of paths (relative
+  to the target directory) to ignore when checking that the package
+  installs correctly cross-compiled binaries. You seldom need to set this
+  variable, unless the package installs binary blobs outside the default
+  locations, `/lib/firmware`, `/usr/lib/firmware`, `/lib/modules`,
+  `/usr/lib/modules`, and `/usr/share`, which are automatically excluded.
+
 The recommended way to define these variables is to use the following
 syntax:
 
@@ -540,6 +560,9 @@ In the action definitions, you can use the following variables:
 * +$(@D)+, which contains the directory in which the package source
   code has been uncompressed.
 
+* +$(DL_DIR)+ contains the path to the directory where all the downloads made
+  by Buildroot are stored.
+
 * +$(TARGET_CC)+, +$(TARGET_LD)+, etc. to get the target
   cross-compilation utilities