diff --git a/racket/src/README b/racket/src/README
index e3bdb12b15..422bc60477 100644
--- a/racket/src/README
+++ b/racket/src/README
@@ -309,6 +309,30 @@ of Android (such as 14), and
 is in your PATH (so that a suitable `gcc', `ar', etc., are found) for
 the [comp] of your choice and the [platform] used to compile.
 
+========================================================================
+ Cross-compiling for iOS
+========================================================================
+
+To compile the Racket runtime system as a Framework for iOS, use (all
+on one line)
+
+  configure --host=[arch]-apple-darwin
+            --enable-ios="[sdk]"
+            --enable-racket=racket
+
+where [arch] is one of
+
+ - armv7, armv7s, or aarch64: to run on iOS
+ - i386 or x86_64: to run on the simulator
+
+The [sdk] argument is a path to an iOS SDK, but if it is "iPhoneOS" or
+"iPhoneSimulator", then the corresponding SDK is located in the
+standard place within the XCode application. For example, "iPhoneOS"
+becomes the path (all on one line)
+
+  /Applications/Xcode.app/Contents/Developer/Platforms/
+    iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk
+
 ========================================================================
  CGC versus 3m
 ========================================================================
diff --git a/racket/src/configure b/racket/src/configure
index 080515eedb..1e3d02b1e9 100755
--- a/racket/src/configure
+++ b/racket/src/configure
@@ -1451,6 +1451,7 @@ Optional Features:
   --enable-sdk=<path>     use Mac OS X 10.4 SDK directory
   --enable-sdk5=<path>    use Mac OS X 10.5 SDK directory
   --enable-sdk6=<path>    use Mac OS X 10.6 SDK directory
+  --enable-ios=<path>     use iOS SDK directory
   --enable-sysroot=<path> use sysroot directory (e.g., for Android)
   --enable-xonx           use Unix style (e.g., use Gtk) for Mac OS X
   --enable-libfw          install Mac OS X frameworks to /Library/Frameworks
@@ -2710,6 +2711,11 @@ if test "${enable_sdk+set}" = set; then :
   enableval=$enable_sdk;
 fi
 
+# Check whether --enable-sdk was given.
+if test "${enable_sdk+set}" = set; then :
+  enableval=$enable_sdk;
+fi
+
 # Check whether --enable-xonx was given.
 if test "${enable_xonx+set}" = set; then :
   enableval=$enable_xonx;
@@ -3052,17 +3058,29 @@ if test "${enable_sdk}" != "" ; then
    if test "${enable_sdk6}" != "" ; then
      echo "ERROR: cannot specify both --enable-sdk and --enable-sdk6"
    fi
+   if test "${enable_ios}" != "" ; then
+     echo "ERROR: cannot specify both --enable-sdk and --enable-ios"
+   fi
    echo "=== Using Mac OS X 10.4 SDK directory ${enable_sdk}"
 fi
 if test "${enable_sdk5}" != "" ; then
    if test "${enable_sdk6}" != "" ; then
      echo "ERROR: cannot specify both --enable-sdk5 and --enable-sdk6"
    fi
+   if test "${enable_ios}" != "" ; then
+     echo "ERROR: cannot specify both --enable-sdk5 and --enable-ios"
+   fi
    echo "=== Using Mac OS X 10.5 SDK directory ${enable_sdk}"
 fi
 if test "${enable_sdk6}" != "" ; then
+   if test "${enable_ios}" != "" ; then
+     echo "ERROR: cannot specify both --enable-sdk6 and --enable-ios"
+   fi
    echo "=== Using Mac OS X 10.6 SDK directory ${enable_sdk6}"
 fi
+if test "${enable_ios}" != "" ; then
+   echo "=== Using ios SDK directory ${enable_ios}"
+fi
 
 if test "${enable_sysroot}" != "" ; then
    echo "=== Using sysroot directory ${enable_sysroot}"
@@ -3222,6 +3240,34 @@ if test "${enable_sysroot}" != "" ; then
    SUB_CONFIGURE_EXTRAS="${SUB_CONFIGURE_EXTRAS} LDFLAGS="'"'"${LDFLAGS}"'"'
 fi
 
+if test "${enable_ios}" != "" ; then
+  case "$host_cpu" in
+    aarch64)
+     IOS_ARCH=arm64
+     ;;
+    *)
+     IOS_ARCH=$host_cpu
+     ;;
+  esac
+  case "${enable_ios}" in
+    iPhoneOS|iPhoneSimulator)
+     ios_sdk=/Applications/Xcode.app/Contents/Developer/Platforms/${enable_ios}.platform/Developer/SDKs/${enable_ios}.sdk
+     ;;
+    *)
+     ios_sdk="${enable_ios}"
+     ;;
+  esac
+  IOS_PHONE_VERS="6.0"
+  PREFLAGS="$PREFLAGS -DTARGET_OS_IPHONE"
+  CPPFLAGS="$CPPFLAGS -DTARGET_OS_IPHONE"
+  PREFLAGS="$PREFLAGS -arch ${IOS_ARCH} -isysroot ${ios_sdk} -miphoneos-version-min=${IOS_PHONE_VERS}"
+  CPPFLAGS="$CPPFLAGS -arch ${IOS_ARCH} -isysroot ${ios_sdk} -miphoneos-version-min=${IOS_PHONE_VERS}"
+  LDFLAGS="$LDFLAGS -arch ${IOS_ARCH} -isysroot ${ios_sdk} -miphoneos-version-min=${IOS_PHONE_VERS} -liconv"
+  SUB_CONFIGURE_EXTRAS="${SUB_CONFIGURE_EXTRAS} CFLAGS="'"'"${CFLAGS}"'"'
+  SUB_CONFIGURE_EXTRAS="${SUB_CONFIGURE_EXTRAS} CPPFLAGS="'"'"${PREFLAGS}"'"'
+  SUB_CONFIGURE_EXTRAS="${SUB_CONFIGURE_EXTRAS} LDFLAGS="'"'"${LDFLAGS}"'"'
+fi
+
 if test "${enable_oskit}" = "no" ; then
   ac_ext=c
 ac_cpp='$CPP $CPPFLAGS'
diff --git a/racket/src/racket/cmdline.inc b/racket/src/racket/cmdline.inc
index caee3c9ab1..c1e8d54ee4 100644
--- a/racket/src/racket/cmdline.inc
+++ b/racket/src/racket/cmdline.inc
@@ -123,7 +123,7 @@ END_XFORM_SKIP;
 #ifdef OS_X
 static long get_segment_offset()
 {
-# ifdef __x86_64__
+# if defined(__x86_64__) || defined(__arm64__)
   const struct segment_command_64 *seg;
 # else
   const struct segment_command *seg;
diff --git a/racket/src/racket/configure.ac b/racket/src/racket/configure.ac
index d0e4dad511..26583d2dde 100644
--- a/racket/src/racket/configure.ac
+++ b/racket/src/racket/configure.ac
@@ -60,6 +60,7 @@ AC_ARG_ENABLE(libffi,  [  --enable-libffi         use installed libffi (enabled
 AC_ARG_ENABLE(sdk,     [  --enable-sdk=<path>     use Mac OS X 10.4 SDK directory])
 AC_ARG_ENABLE(sdk,     [  --enable-sdk5=<path>    use Mac OS X 10.5 SDK directory])
 AC_ARG_ENABLE(sdk,     [  --enable-sdk6=<path>    use Mac OS X 10.6 SDK directory])
+AC_ARG_ENABLE(sdk,     [  --enable-ios=<path>     use iOS SDK directory])
 AC_ARG_ENABLE(sdk,     [  --enable-sysroot=<path> use sysroot directory (e.g., for Android)])
 AC_ARG_ENABLE(xonx,    [  --enable-xonx           use Unix style (e.g., use Gtk) for Mac OS X])
 AC_ARG_ENABLE(libfw,   [  --enable-libfw          install Mac OS X frameworks to /Library/Frameworks])
@@ -335,17 +336,29 @@ if test "${enable_sdk}" != "" ; then
    if test "${enable_sdk6}" != "" ; then
      echo "ERROR: cannot specify both --enable-sdk and --enable-sdk6"
    fi
+   if test "${enable_ios}" != "" ; then
+     echo "ERROR: cannot specify both --enable-sdk and --enable-ios"
+   fi
    echo "=== Using Mac OS X 10.4 SDK directory ${enable_sdk}"
 fi
 if test "${enable_sdk5}" != "" ; then
    if test "${enable_sdk6}" != "" ; then
      echo "ERROR: cannot specify both --enable-sdk5 and --enable-sdk6"
    fi
+   if test "${enable_ios}" != "" ; then
+     echo "ERROR: cannot specify both --enable-sdk5 and --enable-ios"
+   fi
    echo "=== Using Mac OS X 10.5 SDK directory ${enable_sdk}"
 fi
 if test "${enable_sdk6}" != "" ; then
+   if test "${enable_ios}" != "" ; then
+     echo "ERROR: cannot specify both --enable-sdk6 and --enable-ios"
+   fi
    echo "=== Using Mac OS X 10.6 SDK directory ${enable_sdk6}"
 fi
+if test "${enable_ios}" != "" ; then
+   echo "=== Using ios SDK directory ${enable_ios}"
+fi
 
 if test "${enable_sysroot}" != "" ; then
    echo "=== Using sysroot directory ${enable_sysroot}"
@@ -499,6 +512,34 @@ if test "${enable_sysroot}" != "" ; then
    SUB_CONFIGURE_EXTRAS="${SUB_CONFIGURE_EXTRAS} LDFLAGS="'"'"${LDFLAGS}"'"'
 fi
 
+if test "${enable_ios}" != "" ; then
+  case "$host_cpu" in
+    aarch64)
+     IOS_ARCH=arm64
+     ;;
+    *)
+     IOS_ARCH=$host_cpu
+     ;;
+  esac
+  case "${enable_ios}" in
+    iPhoneOS|iPhoneSimulator)
+     ios_sdk=/Applications/Xcode.app/Contents/Developer/Platforms/${enable_ios}.platform/Developer/SDKs/${enable_ios}.sdk
+     ;;
+    *)
+     ios_sdk="${enable_ios}"
+     ;;
+  esac
+  IOS_PHONE_VERS="6.0"
+  PREFLAGS="$PREFLAGS -DTARGET_OS_IPHONE"
+  CPPFLAGS="$CPPFLAGS -DTARGET_OS_IPHONE"
+  PREFLAGS="$PREFLAGS -arch ${IOS_ARCH} -isysroot ${ios_sdk} -miphoneos-version-min=${IOS_PHONE_VERS}"
+  CPPFLAGS="$CPPFLAGS -arch ${IOS_ARCH} -isysroot ${ios_sdk} -miphoneos-version-min=${IOS_PHONE_VERS}"
+  LDFLAGS="$LDFLAGS -arch ${IOS_ARCH} -isysroot ${ios_sdk} -miphoneos-version-min=${IOS_PHONE_VERS} -liconv"
+  SUB_CONFIGURE_EXTRAS="${SUB_CONFIGURE_EXTRAS} CFLAGS="'"'"${CFLAGS}"'"'
+  SUB_CONFIGURE_EXTRAS="${SUB_CONFIGURE_EXTRAS} CPPFLAGS="'"'"${PREFLAGS}"'"'
+  SUB_CONFIGURE_EXTRAS="${SUB_CONFIGURE_EXTRAS} LDFLAGS="'"'"${LDFLAGS}"'"'
+fi
+    
 if test "${enable_oskit}" = "no" ; then
   AC_PROG_CC
   AC_PROG_CPP
@@ -774,7 +815,7 @@ case "$host_os" in
       SUB_CONFIGURE_EXTRAS="${SUB_CONFIGURE_EXTRAS} CPPFLAGS="'"'"${PREFLAGS}"'"'
       SUB_CONFIGURE_EXTRAS="${SUB_CONFIGURE_EXTRAS} LDFLAGS="'"'"${LDFLAGS}"'"'
     fi
-    
+
     case "$host_cpu" in
       i386|x86_64)
        enable_parallel_by_default=yes
diff --git a/racket/src/racket/gc2/vm_osx.c b/racket/src/racket/gc2/vm_osx.c
index adeca943b1..00dbc5ecc5 100644
--- a/racket/src/racket/gc2/vm_osx.c
+++ b/racket/src/racket/gc2/vm_osx.c
@@ -124,6 +124,10 @@ static void unregister_mach_thread() {
 # define ARCH_thread_state_t ppc_thread_state_t
 # define ARCH_THREAD_STATE PPC_THREAD_STATE
 # define ARCH_THREAD_STATE_COUNT PPC_THREAD_STATE_COUNT
+#elif defined(__arm__) || defined(__arm64__)
+# define ARCH_thread_state_t arm_thread_state_t
+# define ARCH_THREAD_STATE ARM_THREAD_STATE
+# define ARCH_THREAD_STATE_COUNT ARM_THREAD_STATE_COUNT
 #elif defined(__x86_64__)
 # define ARCH_thread_state_t x86_thread_state64_t
 # define ARCH_THREAD_STATE x86_THREAD_STATE64
diff --git a/racket/src/racket/sconfig.h b/racket/src/racket/sconfig.h
index 4be9d30fec..d378f54db6 100644
--- a/racket/src/racket/sconfig.h
+++ b/racket/src/racket/sconfig.h
@@ -805,27 +805,25 @@
 
 # if defined(OS_X) || defined(XONX)
 
-#ifdef XONX
-# ifdef __POWERPC__
-#  define SCHEME_PLATFORM_LIBRARY_SUBPATH "ppc-darwin"
+# if defined(XONX)
+#  define SPLS_MAC "darwin"
+# elif defined(TARGET_OS_IPHONE)
+#  define SPLS_MAC "ios"
 # else
-#  ifdef __x86_64__
-#   define SCHEME_PLATFORM_LIBRARY_SUBPATH "x86_64-darwin"
-#  else
-#   define SCHEME_PLATFORM_LIBRARY_SUBPATH "i386-darwin"
-#  endif
+#  define SPLS_MAC "macosx"
 # endif
-#else
-# ifdef __POWERPC__
-#  define SCHEME_PLATFORM_LIBRARY_SUBPATH "ppc-macosx"
+
+# if defined(__POWERPC__)
+#  define SCHEME_PLATFORM_LIBRARY_SUBPATH "ppc-"SPLS_MAC
+# elif defined(__arm__)
+#  define SCHEME_PLATFORM_LIBRARY_SUBPATH "arm-"SPLS_MAC
+# elif defined(__arm64__)
+#  define SCHEME_PLATFORM_LIBRARY_SUBPATH "arm64-"SPLS_MAC
+# elif defined(__x86_64__)
+#   define SCHEME_PLATFORM_LIBRARY_SUBPATH "x86_64-"SPLS_MAC
 # else
-#  ifdef __x86_64__
-#   define SCHEME_PLATFORM_LIBRARY_SUBPATH "x86_64-macosx"
-#  else
-#   define SCHEME_PLATFORM_LIBRARY_SUBPATH "i386-macosx"
-#  endif
+#  define SCHEME_PLATFORM_LIBRARY_SUBPATH "i386-"SPLS_MAC
 # endif
-#endif
 
 # include "uconfig.h"
 
@@ -870,7 +868,10 @@
 #  define OS_X 1
 #endif
 
-#if defined(__POWERPC__)
+#if defined(__arm__)
+# define MZ_USE_JIT_ARM
+#elif defined(__arm64__)
+#elif defined(__POWERPC__)
 # define MZ_USE_JIT_PPC
 #else
 # if defined(__x86_64__)
diff --git a/racket/src/racket/src/lightning/arm/asm-common.h b/racket/src/racket/src/lightning/arm/asm-common.h
index ce518914db..2986b0e8fb 100644
--- a/racket/src/racket/src/lightning/arm/asm-common.h
+++ b/racket/src/racket/src/lightning/arm/asm-common.h
@@ -75,7 +75,7 @@ struct {
 } jit_cpu;
 #endif
 
-struct {
+static struct {
     /* prevent using thumb instructions that set flags? */
     _ui		no_set_flags	: 1;
 } jit_flags;
diff --git a/racket/src/racket/src/lightning/arm/core.h b/racket/src/racket/src/lightning/arm/core.h
index 8be1fa1160..d987566217 100644
--- a/racket/src/racket/src/lightning/arm/core.h
+++ b/racket/src/racket/src/lightning/arm/core.h
@@ -53,8 +53,19 @@ jit_v_order[JIT_V_NUM] = {
 
 #define jit_no_set_flags()		jit_flags.no_set_flags
 
+#ifdef TARGET_OS_IPHONE
+# define USE_SEPARATE_DIV_AND_MOD
+#endif
+
+#ifdef USE_SEPARATE_DIV_AND_MOD
+extern int __divsi3(int, int);
+extern int __udivsi3(int, int);
+extern int __modsi3(int, int);
+extern int __umodsi3(int, int);
+#else
 extern int	__aeabi_idivmod(int, int);
 extern unsigned	__aeabi_uidivmod(unsigned, unsigned);
+#endif
 
 #define jit_nop(n)			arm_nop(_jitp, n)
 __jit_inline void
@@ -855,8 +866,18 @@ arm_divmod(jit_state_t _jitp, int div, int sign,
     jit_movr_i(_R0, r1);
     jit_movr_i(_R1, r2);
   }
+#ifdef USE_SEPARATE_DIV_AND_MOD
+  if (div) {
+    if (sign) p = __divsi3;
+    else p = __udivsi3;
+  } else {
+    if (sign) p = __modsi3;
+    else p = __umodsi3;
+  }
+#else
   if (sign)		p = __aeabi_idivmod;
   else		p = __aeabi_uidivmod;
+#endif
   {
     jit_movi_i(JIT_FTMP, (int)p);
     if (jit_thumb_p())
@@ -864,10 +885,14 @@ arm_divmod(jit_state_t _jitp, int div, int sign,
     else
       _BLX(JIT_FTMP);
   }
+#ifdef USE_SEPARATE_DIV_AND_MOD
+  jit_movr_i(r0, _R0);
+#else
   if (div)
     jit_movr_i(r0, _R0);
   else
     jit_movr_i(r0, _R1);
+#endif
   if (jit_thumb_p())
     T1_POP(l);
   else
diff --git a/racket/src/racket/src/lightning/arm/funcs.h b/racket/src/racket/src/lightning/arm/funcs.h
index cd079d0e50..3f35532ba8 100644
--- a/racket/src/racket/src/lightning/arm/funcs.h
+++ b/racket/src/racket/src/lightning/arm/funcs.h
@@ -42,7 +42,13 @@
 
 #define jit_notify_freed_code() /* empty */
 
-extern void __clear_cache(void*, void*);
+#ifdef TARGET_OS_IPHONE
+void sys_icache_invalidate(void *start, size_t len);
+# define CLEAR_ICACHE(s, e) sys_icache_invalidate(s, ((char *)e) - ((char *)s));
+#else
+extern void _clear_cache(void*, void*);
+# define CLEAR_ICACHE(s, e) __clear_cache(s, e)
+#endif
 
 __jit_inline void
 jit_flush_code(void *start, void *end)
@@ -54,10 +60,10 @@ jit_flush_code(void *start, void *end)
     void *e;
     e = (void *)(((uintptr_t)start + 4096) & ~4095);
     if (e < end) {
-      __clear_cache(start, e);
+      CLEAR_ICACHE(start, e);
       start = e;
     } else {
-      __clear_cache(start, end);
+      CLEAR_ICACHE(start, end);
       break;
     }
   }
diff --git a/racket/src/racket/src/string.c b/racket/src/racket/src/string.c
index 50a8f82f0a..03b180a49e 100644
--- a/racket/src/racket/src/string.c
+++ b/racket/src/racket/src/string.c
@@ -2157,7 +2157,7 @@ int scheme_any_string_has_null(Scheme_Object *o)
 /* Environment Variables                                               */
 /***********************************************************************/
 
-#ifdef OS_X
+#if defined(OS_X) && !defined(TARGET_OS_IPHONE)
 # include <crt_externs.h>
 # define GET_ENVIRON_ARRAY *_NSGetEnviron()
 #endif