1 files changed, 30 insertions, 11 deletions
diff --git a/tensorflow/contrib/makefile/README.md b/tensorflow/contrib/makefile/README.md
index 715eb51577..65bd60c12a 100644
--- a/tensorflow/contrib/makefile/README.md
+++ b/tensorflow/contrib/makefile/README.md
@@ -174,10 +174,26 @@ tensorflow/contrib/makefile/build_all_ios.sh
 
 This process will take around twenty minutes on a modern MacBook Pro.
 
-When it completes, you will have a library for a single architecture and the
-benchmark program. Although successfully compiling the benchmark program is a
+When it completes, you will have a unified library for all architectures
+(i386sim, x86_64sim, armv7, armv7s and arm64)  and the benchmark program.
+Although successfully compiling the benchmark program is a
 sign of success, the program is not a complete iOS app.
 
+If you would only like to build only one architecture to save time:
+(iOS 11+ only supports 64bit so you can get away with arm64)
+
+```bash
+tensorflow/contrib/makefile/build_all_ios.sh -a arm64
+```
+
+After the first build if you would like to just build the tensorflow
+library you can pass the -T flag to avoid a clean & rebuild. This should
+take you just a few seconds to generate the library if you modified one file.
+
+```bash
+tensorflow/contrib/makefile/build_all_ios.sh -a arm64 -T
+```
+
 To see TensorFlow running on iOS, the example Xcode project in
 [tensorflow/examples/ios](../../examples/ios/) shows how to use the static
 library in a simple app.
@@ -193,19 +209,18 @@ If you have not already, you will need to download dependencies:
 tensorflow/contrib/makefile/download_dependencies.sh
 ```
 
-Next, you will need to compile protobufs for iOS:
+Next, you will need to compile protobufs for iOS (optionally takes the -a $ARCH flag):
 
 ```bash
-tensorflow/contrib/makefile/compile_ios_protobuf.sh 
+tensorflow/contrib/makefile/compile_ios_protobuf.sh
 ```
 
-Then, you will need to compile the nsync library for iOS:
+Then, you will need to compile the nsync library for iOS (optionally takes -a $ARCH flag):
 
 ```bash
 export HOST_NSYNC_LIB=`tensorflow/contrib/makefile/compile_nsync.sh`
 export TARGET_NSYNC_LIB=`tensorflow/contrib/makefile/compile_nsync.sh -t ios`
 ```
-
 Then, you can run the makefile specifying iOS as the target, along with the
 architecture you want to build for:
 
@@ -219,10 +234,6 @@ This creates a library in
 `tensorflow/contrib/makefile/gen/lib/libtensorflow-core.a` that you can link any
 xcode project against. 
 
-At this point, you will have a library for a single architecture and the
-benchmark program. Although successfully compiling the benchmark program is a
-sign of success, the program is not a complete iOS app. 
-
 To see TensorFlow running on iOS, the example Xcode project in
 [tensorflow/examples/ios](../../examples/ios/) shows how to use the static
 library in a simple app.
@@ -237,6 +248,14 @@ time follow it with:
 compile_ios_tensorflow.sh
 ```
 
+`compile_ios_tensorflow.sh` takes the -a flag to build only for one architecture.
+In case you run into issues with unresolved symbols with nsync you can also pass
+-h ${HOST_NSYNC_LIB} and -n {TARGET_NSYNC_LIB} so it would look like:
+
+```bash
+tensorflow/contrib/makefile/compile_ios_tensorflow.sh -f "-O3" -h tensorflow/contrib/makefile/downloads/nsync/builds/default.macos.c++11/nsync.a -n tensorflow/contrib/makefile/downloads/nsync/builds/lipo.ios.c++11/nsync.a -a arm64
+```
+
 In XCode, you will need to use -force_load in the linker flags
 section of the build settings to pull in the global constructors that are used
 to register ops and kernels. 
@@ -249,7 +268,7 @@ debug mode. If you are concerned about performance or are working on a release
 build, you would likely want a higher optimization setting, like so:
  
 ```bash
-compile_ios_tensorflow.sh "-Os"
+compile_ios_tensorflow.sh -f "-Os"
 ```
 
 For other variations of valid optimization flags, see [clang optimization levels](http://stackoverflow.com/questions/15548023/clang-optimization-levels).