Add RBC board configuration

This does largely the same thing as in product configuration,
it converts the board makefiles and evaluates them in place
of an $(include).

Bug: 201700692
Test: Temporarily replace the ifndef RBC_BOARD_CONFIG with RBC_PRODUCT_CONFIG,
      then ./build/bazel/ci/rbc_product_config.sh aosp_arm64-userdebug
Change-Id: I91c3dd6b91cf6bfeb18a5fff95d53b7a2c113c57
diff --git a/core/board_config.mk b/core/board_config.mk
index 281ab16..0ad49c8 100644
--- a/core/board_config.mk
+++ b/core/board_config.mk
@@ -184,7 +184,20 @@
   .KATI_READONLY := TARGET_DEVICE_DIR
 endif
 
+# TODO(colefaust) change this if to RBC_PRODUCT_CONFIG when
+# the board configuration is known to work on everything
+# the product config works on.
+ifndef RBC_BOARD_CONFIG
 include $(board_config_mk)
+else
+  rc := $(shell build/soong/scripts/rbc-run $(board_config_mk) \
+      BUILDING_GSI=$(BUILDING_GSI) >$(OUT_DIR)/rbcboardtemp.mk || echo $$?)
+  ifneq (,$(rc))
+    $(error board configuration converter failed: $(rc))
+  endif
+
+  include $(OUT_DIR)/rbcboardtemp.mk
+endif
 
 ifneq (,$(and $(TARGET_ARCH),$(TARGET_ARCH_SUITE)))
   $(error $(board_config_mk) erroneously sets both TARGET_ARCH and TARGET_ARCH_SUITE)
diff --git a/core/product_config.mk b/core/product_config.mk
index b631294..64c23ae 100644
--- a/core/product_config.mk
+++ b/core/product_config.mk
@@ -199,12 +199,8 @@
 ifndef RBC_PRODUCT_CONFIG
 $(call import-products, $(current_product_makefile))
 else
-  rbcscript=build/soong/scripts/rbc-run
-  rc := $(shell $(rbcscript) $(TARGET_PRODUCT)-$(TARGET_BUILD_VARIANT) >$(OUT_DIR)/rbctemp.mk 2>$(OUT_DIR)/rbctemp.stderr || echo $$?)
-  rbcerrors := $(file <$(OUT_DIR)/rbctemp.stderr)
-  ifneq (,$(rbcerrors))
-    $(warning $(rbcerrors))
-  endif
+  rc := $(shell build/soong/scripts/rbc-run $(current_product_makefile) \
+      >$(OUT_DIR)/rbctemp.mk || echo $$?)
   ifneq (,$(rc))
     $(error product configuration converter failed: $(rc))
   endif
diff --git a/core/product_config.rbc b/core/product_config.rbc
index 9fa4a8c..5219751 100644
--- a/core/product_config.rbc
+++ b/core/product_config.rbc
@@ -84,7 +84,7 @@
                         print("SOONG_CONFIG_" + nsname, ":=", " ".join(nsvars.keys()))
                     for var, val in sorted(nsvars.items()):
                         __print_attr("SOONG_CONFIG_%s_%s" % (nsname, var), val)
-            elif attr not in globals_base:
+            elif attr not in globals_base or globals_base[attr] != val:
                 __print_attr(attr, val)
 
 def __printvars_rearrange_list(value_list):