freescale-imx: Add helper to extract self-extractible binaries

[Thomas:
 - reword the comment of the new macro, and add details about the
   expected arguments, as suggested by Yann E. Morin.
 - rework the logic to move the files in $(@D), as it was simply not
   working in the original patch. $(basename $(1)) was used to get the
   filename without the extension, but it also contains the full
   path. $(basename $(notdir $(1))) is needed.]

Signed-off-by: Jérôme Pouiller <jezz@sysmic.org>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/freescale-imx/freescale-imx.mk

@@ -7,4 +7,29 @@
 FREESCALE_IMX_VERSION = 3.10.17-1.0.0
 FREESCALE_IMX_SITE = http://www.freescale.com/lgfiles/NMG/MAD/YOCTO
 
+# Helper for self-extracting binaries distributed by Freescale.
+#
+# The --force option makes sure it doesn't fail if the source
+# directory already exists. The --auto-accept skips the license check,
+# as it is not needed in Buildroot because we have legal-info. Since
+# there's a EULA in the binary file, we extract it in this macro, and
+# it should therefore be added to the LICENSE_FILES variable of
+# packages using this macro. Also, remember to set REDISTRIBUTE to
+# "NO". Indeed, this is a legal minefield: the EULA specifies that the
+# Board Support Package includes software and hardware (sic!) for
+# which a separate license is needed...
+#
+# $(1): full path to the archive file
+#
+define FREESCALE_IMX_EXTRACT_HELPER
+	awk 'BEGIN      { start = 0; } \
+	     /^EOEULA/  { start = 0; } \
+	                { if (start) print; } \
+	     /<<EOEULA/ { start = 1; }' \
+	    $(1) > $(@D)/EULA
+	cd $(@D) && sh $(1) --force --auto-accept
+	find $(@D)/$(basename $(notdir $(1))) -mindepth 1 -maxdepth 1 -exec mv {} $(@D) \;
+	rmdir $(@D)/$(basename $(notdir $(1)))
+endef
+
 include $(sort $(wildcard package/freescale-imx/*/*.mk))