--- old/make/defs.make	2015-02-18 18:53:27.447240158 -0500
+++ new/make/defs.make	2015-02-18 18:53:26.475185111 -0500
@@ -286,7 +286,7 @@
 
   # 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 aarch64 zero,$(ARCH)))
+  SRCARCH    ?= $(ARCH/$(filter sparc sparc64 ia64 amd64 x86_64 ppc64 aarch64 zero,$(ARCH)))
   ARCH/       = x86
   ARCH/sparc  = sparc
   ARCH/sparc64= sparc
@@ -294,13 +294,11 @@
   ARCH/amd64  = x86
   ARCH/x86_64 = x86
   ARCH/ppc64  = ppc
-  ARCH/ppc    = ppc
-  ARCH/arm    = arm
   ARCH/aarch64= aarch64
   ARCH/zero   = zero
 
   # BUILDARCH is usually the same as SRCARCH, except for sparcv9
-  BUILDARCH = $(SRCARCH)
+  BUILDARCH ?= $(SRCARCH)
   ifeq ($(BUILDARCH), x86)
     ifdef LP64
       BUILDARCH = amd64
@@ -320,7 +318,7 @@
   endif
 
   # LIBARCH is 1:1 mapping from BUILDARCH
-  LIBARCH         = $(LIBARCH/$(BUILDARCH))
+  LIBARCH        ?= $(LIBARCH/$(BUILDARCH))
   LIBARCH/i486    = i386
   LIBARCH/amd64   = amd64
   LIBARCH/sparc   = sparc
@@ -328,8 +326,6 @@
   LIBARCH/ia64    = ia64
   LIBARCH/ppc64   = ppc64
   LIBARCH/aarch64 = aarch64
-  LIBARCH/ppc     = ppc
-  LIBARCH/arm     = arm
   LIBARCH/zero    = $(ZERO_LIBARCH)
 
   LP64_ARCH = sparcv9 amd64 ia64 ppc64 aarch64 zero