Cross-compiling for iOS on Linux¶
The procedure for this is somewhat complex and requires a lot of steps, but once you have the environment properly configured it will be easy to compile Godot for iOS anytime you want.
While it is possible to compile for iOS on a Linux environment, Apple is very restrictive about the tools to be used (especially hardware-wise), allowing pretty much only their products to be used for development. So this is not official. However, a statement from Apple in 2010 says they relaxed some of the App Store review guidelines to allow any tool to be used, as long as the resulting binary does not download any code, which means it should be OK to use the procedure described here and cross-compiling the binary.
- XCode with the iOS SDK (a dmg image)
- Clang >= 3.5 for your development
machine installed and in the
PATH. It has to be version >= 3.5 to target
- Fuse for mounting and umounting the dmg image.
- darling-dmg, which
needs to be built from source. The procedure for that is explained
- For building darling-dmg, you’ll need the development packages of the following libraries: fuse, icu, openssl, zlib, bzip2.
for the needed build tools. The procedure for building is quite
peculiar and is described below.
- This also has some extra dependencies: automake, autogen, libtool.
Configuring the environment¶
Clone the repository on your machine:
$ git clone https://github.com/darlinghq/darling-dmg.git
$ cd darling-dmg $ mkdir build $ cd build $ cmake .. -DCMAKE_BUILD_TYPE=Release $ make -j 4 # The number is the amount of cores your processor has, for faster build $ cd ../..
Preparing the SDK¶
Mount the XCode image:
$ mkdir xcode $ ./darling-dmg/build/darling-dmg /path/to/Xcode_7.1.1.dmg xcode [...] Everything looks OK, disk mounted
Extract the iOS SDK:
$ mkdir -p iPhoneSDK/iPhoneOS9.1.sdk $ cp -r xcode/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/* iPhoneSDK/iPhoneOS9.1.sdk $ cp -r xcode/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/* iPhoneSDK/iPhoneOS9.1.sdk/usr/include/c++ $ fusermount -u xcode # unmount the image
Pack the SDK:
$ cd iPhoneSDK $ tar -cf - * | xz -9 -c - > iPhoneOS9.1.sdk.tar.xz
$ git clone https://github.com/tpoechtrager/cctools-port.git $ cd cctools-port/usage_examples/ios_toolchain $ ./build.sh /path/iPhoneOS9.1.sdk.tar.xz arm64
Copy the tools to a nicer place. Note that the SCons scripts for
building will look under
usr/bin inside the directory you provide
for the toolchain binaries, so you must copy to such subdirectory, akin
to the following commands:
$ mkdir -p /home/user/iostoolchain/usr $ cp -r target/bin /home/user/iostoolchain/usr/
Now you should have the iOS toolchain binaries in
Compiling Godot for iPhone¶
Once you’ve done the above steps, you should keep two things in your environment: the built toolchain and the iPhoneOS SDK directory. Those can stay anywhere you want since you have to provide their paths to the SCons build command.
For the iPhone platform to be detected, you need the
environment variable defined to anything.
$ export OSXCROSS_IOS=anything
Now you can compile for iPhone using SCons like the standard Godot way, with some additional arguments to provide the correct paths:
$ scons -j 4 platform=iphone arch=arm target=release_debug IPHONESDK="/path/to/iPhoneSDK" IPHONEPATH="/path/to/iostoolchain" ios_triple="arm-apple-darwin11-" $ scons -j 4 platform=iphone arch=arm64 target=release_debug IPHONESDK="/path/to/iPhoneSDK" IPHONEPATH="/path/to/iostoolchain" ios_triple="arm-apple-darwin11-"
Producing fat binaries¶
Apple requires a fat binary with both architectures (
arm64) in a single file. To do this, use the
arm-apple-darwin11-lipo executable. The following example assumes
you are in the root Godot source directory:
$ /path/to/iostoolchain/usr/bin/arm-apple-darwin11-lipo -create bin/godot.iphone.opt.debug.arm bin/godot.iphone.opt.debug.arm64 -output bin/godot.iphone.opt.debug.fat
Then you will have an iOS fat binary in