--- old/make/defs.make	2015-02-18 17:37:34.606124886 -0500
+++ new/make/defs.make	2015-02-18 17:37:33.726075095 -0500
@@ -273,7 +273,7 @@
 
   # Use uname output for SRCARCH, but deal with platform differences. If ARCH
   # is not explicitly listed below, it is treated as x86.
-  SRCARCH     = $(ARCH/$(filter sparc sparc64 ia64 amd64 x86_64 arm ppc ppc64 zero,$(ARCH)))
+  SRCARCH    ?= $(ARCH/$(filter sparc sparc64 ia64 amd64 x86_64 ppc64 zero,$(ARCH)))
   ARCH/       = x86
   ARCH/sparc  = sparc
   ARCH/sparc64= sparc
@@ -281,12 +281,10 @@
   ARCH/amd64  = x86
   ARCH/x86_64 = x86
   ARCH/ppc64  = ppc
-  ARCH/ppc    = ppc
-  ARCH/arm    = arm
   ARCH/zero   = zero
 
   # BUILDARCH is usually the same as SRCARCH, except for sparcv9
-  BUILDARCH = $(SRCARCH)
+  BUILDARCH ?= $(SRCARCH)
   ifeq ($(BUILDARCH), x86)
     ifdef LP64
       BUILDARCH = amd64
@@ -306,18 +304,16 @@
   endif
 
   # LIBARCH is 1:1 mapping from BUILDARCH
-  LIBARCH         = $(LIBARCH/$(BUILDARCH))
+  LIBARCH        ?= $(LIBARCH/$(BUILDARCH))
   LIBARCH/i486    = i386
   LIBARCH/amd64   = amd64
   LIBARCH/sparc   = sparc
   LIBARCH/sparcv9 = sparcv9
   LIBARCH/ia64    = ia64
   LIBARCH/ppc64   = ppc64
-  LIBARCH/ppc     = ppc
-  LIBARCH/arm     = arm
   LIBARCH/zero    = $(ZERO_LIBARCH)
 
-  LP64_ARCH = sparcv9 amd64 ia64 ppc64 zero
+  LP64_ARCH += sparcv9 amd64 ia64 ppc64 zero
 endif
 
 # Required make macro settings for all platforms