Support x86+arm multilib build.
Support TARGET_2ND_ARCH as the binary translation arch.
See target/board/generic_x86_arm/BoardConfig.mk and
target/product/aosp_x86_arm.mk as example for the setup.
In BoardConfig, use the TARGET_2ND_ARCH/etc. variables to set up the
binary translation arch;
Set "TARGET_TRANSLATE_2ND_ARCH := true" to tell the build system it's
not a typical 64-bit multilib configuration.
In product makefile, use "PRODUCT_PACKAGES += libfoo_<2nd_arch>" to
install the TARGET_2ND_ARCH libraries. This also pulls in any dependency
libraries.
By default we don't install any TARGET_2ND_ARCH modules, unless it's
pulled in by PRODUCT_PACKAGES.
Bug: 27526885
Change-Id: I0578e9c80da0532d2fa886a8fcdb140bbc703009
(cherry-pick from commit 277e75a488b1b6599482aed9f7c046747baa10df)
diff --git a/core/package.mk b/core/package.mk
index 78b65db..8c2c435 100644
--- a/core/package.mk
+++ b/core/package.mk
@@ -2,6 +2,10 @@
# TARGET_ARCH and TARGET_2ND_ARCH.
# To build it for TARGET_2ND_ARCH in a 64bit product, use "LOCAL_MULTILIB := 32".
+ifeq ($(TARGET_TRANSLATE_2ND_ARCH),true)
+LOCAL_MULTILIB := first
+endif
+
my_prefix := TARGET_
include $(BUILD_SYSTEM)/multilib.mk