diff --git a/configure/os/CONFIG.Common.iosCommon b/configure/os/CONFIG.Common.iosCommon
index 0bd045027..7e530fc01 100644
--- a/configure/os/CONFIG.Common.iosCommon
+++ b/configure/os/CONFIG.Common.iosCommon
@@ -53,13 +53,15 @@ OPT_CXXFLAGS_YES += -g
 
 CC_GNU  = gcc
 CCC_GNU = g++
-CC_LLVM  = llvm-gcc
-CCC_LLVM = llvm-g++
+
+CC_LLVM_GNU  = llvm-gcc
+CCC_LLVM_GNU = llvm-g++
+
 CC_CLANG  = clang
 CCC_CLANG = clang++
 
-CC = $(firstword $(wildcard $(GNU_BIN)/$(CC_$(COMPILER))) $(CC_$(COMPILER)))
-CCC = $(firstword $(wildcard $(GNU_BIN)/$(CCC_$(COMPILER))) $(CCC_$(COMPILER)))
+# Convert the iOS platform to lowercase for passing to xcrun's sdk parameter
+XCRUN_SDK_BASE = $(shell echo $(IOS_PLATFORM) | tr A-Z a-z)
 
 #-------------------------------------------------------
 # Linker flags
@@ -70,7 +72,7 @@ OP_SYS_LDFLAGS += -dynamic -Z -L$(SDK_DIR)/usr/lib -L$(SDK_DIR)/usr/lib/system
 # Shared libraries
 SHRLIB_VERSION = $(EPICS_VERSION).$(EPICS_REVISION).$(EPICS_MODIFICATION)
 SHRLIB_LDFLAGS = -dynamiclib -flat_namespace -undefined suppress \
-       -install_name $(shell perl $(TOOLS)/fullPathName.pl $(INSTALL_LIB))/$@ \
+       -install_name $(shell $(PERL) $(TOOLS)/fullPathName.pl $(INSTALL_LIB))/$@ \
        -compatibility_version $(EPICS_VERSION).$(EPICS_REVISION) \
        -current_version $(SHRLIB_VERSION)
 SHRLIB_SUFFIX_BASE = .dylib
@@ -93,13 +95,14 @@ vpath %.m $(USR_VPATH) $(ALL_SRC_DIRS)
 #--------------------------------------------------
 # Header dependency file generation
 #
-# Use compiler when ARCH_CLASS is a single arch value
-# otherwise use perl script command
-SINGLE_ARCH=$(filter 1,$(words $(ARCH_CLASS)))
-HDEPENDS_CFLAGS = $(if $(SINGLE_ARCH),$(HDEPENDS_CFLAGS_$(HDEPENDS)))
-HDEPENDS_METHOD = $(if $(SINGLE_ARCH),CFLAGS,CMD)
+HDEPENDS_METHOD = CMD
 
 #--------------------------------------------------
 # Allow site overrides
 -include $(CONFIG)/os/CONFIG_SITE.Common.iosCommon
 -include $(CONFIG)/os/CONFIG_SITE.$(EPICS_HOST_ARCH).iosCommon
+
+#--------------------------------------------------
+# Find the Xcode compilers for the specified SDK just once
+CC := $(shell xcrun -sdk $(XCRUN_SDK_BASE) -find $(CC_$(COMPILER)))
+CCC := $(shell xcrun -sdk $(XCRUN_SDK_BASE) -find $(CCC_$(COMPILER)))
diff --git a/configure/os/CONFIG.darwinCommon.darwinCommon b/configure/os/CONFIG.darwinCommon.darwinCommon
index 7e02bbf82..a330190ed 100644
--- a/configure/os/CONFIG.darwinCommon.darwinCommon
+++ b/configure/os/CONFIG.darwinCommon.darwinCommon
@@ -67,7 +67,7 @@ CCC = $(GNU_BIN)/c++
 #
 SHRLIB_VERSION = $(EPICS_VERSION).$(EPICS_REVISION).$(EPICS_MODIFICATION)
 SHRLIB_LDFLAGS = -dynamiclib -flat_namespace -undefined suppress \
-       -install_name $(shell perl $(TOOLS)/fullPathName.pl $(INSTALL_LIB))/$@ \
+       -install_name $(shell $(PERL) $(TOOLS)/fullPathName.pl $(INSTALL_LIB))/$@ \
        -compatibility_version $(EPICS_VERSION).$(EPICS_REVISION) \
        -current_version $(SHRLIB_VERSION)
 SHRLIB_SUFFIX_BASE = .dylib
diff --git a/configure/os/CONFIG_SITE.Common.ios-arm b/configure/os/CONFIG_SITE.Common.ios-arm
index 462db67f8..e6ae3fcc1 100644
--- a/configure/os/CONFIG_SITE.Common.ios-arm
+++ b/configure/os/CONFIG_SITE.Common.ios-arm
@@ -1,21 +1,26 @@
 # CONFIG_SITE.Common.ios-arm
 #
 # $Revision-Id$
-# This file is maintained by the build community.
 #
 # Site-specific settings for ios-arm target builds
 #-------------------------------------------------------
 
 # Which ARM instruction set(s) to generate code for:
-#   Most iOS devices can run programs compiled for both the
-#   ARMv6 and ARMv7 instruction sets. ARMv7 code is usually
-#   more efficient, but the older devices listed below can only
-#   use the ARMv6 instruction set. Including both architectures
-#   generates a Universal binary, which is larger and takes
-#   longer to compile but runs efficiently on all devices.
+#   Most iOS devices can run programs compiled for older
+#   instruction sets, although the newer instructions are
+#   more efficient.
 #
-#   ARMv6-only devices: iPhone 1 or 3G, iPod Touch Gen 1 or 2
+#   Apple's compilers can build for multiple architectures,
+#   generating a Universal binary.  This is larger and takes
+#   longer to compile, but runs efficiently on all devices.
 #
-ARCH_CLASS = armv7
+#   Xcode 4.5 dropped support for the ARMv6.
+#
+#   ARMv7s devices: iPhone 5
+#   ARMv6 devices: iPhone 1 and 3G, iPod Touch Gen 1 and 2
+#   All other devices are ARMv7
+
+ARCH_CLASS = armv7 armv7s
+#ARCH_CLASS = armv7
 #ARCH_CLASS = armv6 armv7
 #ARCH_CLASS = armv6
diff --git a/configure/os/CONFIG_SITE.Common.iosCommon b/configure/os/CONFIG_SITE.Common.iosCommon
index a41721621..0fa3d4523 100644
--- a/configure/os/CONFIG_SITE.Common.iosCommon
+++ b/configure/os/CONFIG_SITE.Common.iosCommon
@@ -1,7 +1,6 @@
 # CONFIG_SITE.Common.iosCommon
 #
 # $Revision-Id$
-# This file is maintained by the build community.
 #
 # Site-specific settings for Apple iOS builds
 #-------------------------------------------------------
@@ -12,16 +11,18 @@
 #IOS_VERSION = 4.1
 #IOS_VERSION = 4.2
 #IOS_VERSION = 4.3
-IOS_VERSION = 5.0
+#IOS_VERSION = 5.0
+#IOS_VERSION = 5.1
+IOS_VERSION = 6.0
 
 
 # Which compiler to use:
 #   CLANG is preferred for recent versions of Xcode
-#   LLVM uses the llvm-gcc and llvm-g++ compilers
+#   LLVM_GNU uses the llvm-gcc and llvm-g++ compilers
 #   GNU is needed for older versions of Xcode
 
 COMPILER = CLANG
-#COMPILER = LLVM
+#COMPILER = LLVM_GNU
 #COMPILER = GNU