android: add a script to regenerate prebuilt config

since x86 CROSS_COMPILER removal, it can be hard to do that properly

Change-Id: I6011e3b4dac5b5e670385df4812baf32f2e5ebc5

Author: tpruvot

android_config.sh

@@ -0,0 +1,19 @@
+# Use ". android_config.sh" to refresh prebuilt android config
+# Note: this rebuild the compressed usage ressources and should be done
+#       in a separate commit, to ignore it on future merge/rebase
+
+make mrproper
+
+cp .config-minimal .config
+echo >> .config
+echo 'CONFIG_CROSS_COMPILER_PREFIX="arm-eabi-"' >> .config
+make prepare
+cd include-minimal && ./copy-current.sh
+cd ..
+
+cp .config-full .config
+echo >> .config
+echo 'CONFIG_CROSS_COMPILER_PREFIX="arm-eabi-"' >> .config
+make prepare
+cd include-full && ./copy-current.sh
+cd ..

include-full/copy-current.sh

@@ -2,7 +2,7 @@
 # this step is no more required to build busybox, it is made automatically
 # in Android.mk (busybox_prepare module)
 
-cp ../.config ../.config-full
+cat ../.config | grep -v CONFIG_CROSS_COMPILER_PREFIX > ../.config-full
 
 cp ../include/applets.h ./
 cp ../include/applet_tables.h ./

include-minimal/copy-current.sh

@@ -2,7 +2,7 @@
 # this step is no more required to build busybox, it is made automatically
 # in Android.mk (busybox_prepare module)
 
-cp ../.config ../.config-minimal
+cat ../.config | grep -v CONFIG_CROSS_COMPILER_PREFIX > ../.config-minimal
 
 cp ../include/applets.h ./
 cp ../include/applet_tables.h ./