Clarify the use of --boot-dirs in the header comment.
Change-Id: I89cf275e6188d5615bfb4e45fe35580b0ebe5be2
diff --git a/tools/dex-preopt b/tools/dex-preopt
index 6ac5a6b..b2bc2c4 100755
--- a/tools/dex-preopt
+++ b/tools/dex-preopt
@@ -41,9 +41,13 @@
# not specified, then there must only be one such directory, and that
# one will be used.
# --boot-jars=list:of:jar:base:names -- Specify the list of base names
-# of bootstrap classpath elements, colon-separated. This defaults to
-# "core". However, as of this writing, a good choice to pass in here
-# is "core:core-junit:ext:framework:android.policy:services".
+# of bootstrap classpath elements, colon-separated. Order is significant
+# and must match the BOOTCLASSPATH that is eventually specified at
+# runtime on the device. This defaults to "core". However, this really
+# needs to match the target product's BOOTCLASSPATH, which, as of this
+# writing, doesn't have a super-strict way of being defined within the
+# build. You can find variations of it in different init.rc files under
+# system/core/rootdir or under product-specific directories.
# --verify={none,remote,all} -- Specify what level of verification to
# do. Defaults to "all".
# --optimize={none,verified,all} -- Specify which classes to optimize.
