Building xnu for OS X 10.10 Yosemite

The OS X kernel source (xnu) has been released for OS X 10.10 Yosemite: here

Building xnu requires Xcode and some additional open-source (but not pre-installed) dependencies. You can build xnu manually by doing:

1. Install OS X Yosemite and Xcode 6.1 from the Mac App Store, make sure the Xcode license has been agreed-to with "sudo xcodebuild -license"
2. Download the source for the dtrace and AvailabilityVersions projects, which are required dependencies, as well as xnu itself
   

   $ curl -O http://opensource.apple.com/tarballs/dtrace/dtrace-147.tar.gz
   $ curl -O http://opensource.apple.com/tarballs/AvailabilityVersions/AvailabilityVersions-9.tar.gz
   $ curl -O http://opensource.apple.com/tarballs/xnu/xnu-2782.1.97.tar.gz

3. Build and install CTF tools from dtrace
   

   $ tar zxf dtrace-147.tar.gz
   $ cd dtrace-147
   $ mkdir -p obj sym dst
   $ xcodebuild install -target ctfconvert -target ctfdump -target ctfmerge ARCHS="x86_64" SRCROOT=$PWD OBJROOT=$PWD/obj SYMROOT=$PWD/sym DSTROOT=$PWD/dst
   ...
   $ sudo ditto $PWD/dst/usr/local /usr/local
   Password:
   $ cd ..
   

4. Install AvailabilityVersions
   

   $ tar zxf AvailabilityVersions-9.tar.gz
   $ cd AvailabilityVersions-9
   $ mkdir -p dst
   $ make install SRCROOT=$PWD DSTROOT=$PWD/dst
   $ sudo ditto $PWD/dst/usr/local `xcrun -sdk macosx -show-sdk-path`/usr/local
   $ cd ..
   

5. Build xnu
   

   $ tar zxf xnu-2782.1.97.tar.gz
   $ cd xnu-2782.1.97
   $ make SDKROOT=macosx ARCH_CONFIGS=X86_64 KERNEL_CONFIGS=RELEASE

See xnu's top-level README for additional build variables that can be passed on the command-line, such as BUILD_LTO=0 .

Update: If you are attempting to add system calls, you may also need to build Libsyscall.

1. Download the Libsystem source

   $ curl -O http://opensource.apple.com/tarballs/Libsystem/Libsystem-1213.tar.gz
   

2. Install Libsystem headers

   $ tar zxf Libsystem-1213.tar.gz 
   $ cd Libsystem-1213
   $ xcodebuild installhdrs -sdk macosx ARCHS='x86_64 i386' SRCROOT=$PWD OBJROOT=$PWD/obj SYMROOT=$PWD/sym DSTROOT=$PWD/dst
   $ sudo ditto $PWD/dst `xcrun -sdk macosx -show-sdk-path`
   $ cd ..
   

3. Install xnu and Libsyscall headers

   $ cd xnu-2782.1.97
   $ mkdir -p BUILD.hdrs/obj BUILD.hdrs/sym BUILD.hdrs/dst
   $ make installhdrs SDKROOT=macosx ARCH_CONFIGS=X86_64 SRCROOT=$PWD OBJROOT=$PWD/BUILD.hdrs/obj SYMROOT=$PWD/BUILD.hdrs/sym DSTROOT=$PWD/BUILD.hdrs/dst
   $ xcodebuild installhdrs -project libsyscall/Libsyscall.xcodeproj -sdk macosx ARCHS='x86_64 i386' SRCROOT=$PWD/libsyscall OBJROOT=$PWD/BUILD.hdrs/obj SYMROOT=$PWD/BUILD.hdrs/sym DSTROOT=$PWD/BUILD.hdrs/dst
   $ sudo ditto BUILD.hdrs/dst `xcrun -sdk macosx -show-sdk-path`

4. Build Libsyscall

   $ mkdir -p BUILD.libsyscall/obj BUILD.libsyscall/sym BUILD.libsyscall/dst
   $ xcodebuild install -project libsyscall/Libsyscall.xcodeproj -sdk macosx ARCHS='x86_64 i386' SRCROOT=$PWD/libsyscall OBJROOT=$PWD/BUILD.libsyscall/obj SYMROOT=$PWD/BUILD.libsyscall/sym DSTROOT=$PWD/BUILD.libsyscall/dst
   

Building xnu for OS X 10.9 Mavericks

The OS X kernel source (xnu) has been released for OS X 10.9 Mavericks: here

Building xnu requires Xcode and some additional open-source (but not pre-installed) dependencies. You can build xnu manually by doing:

1. Install OS X Mavericks and Xcode 5.0.1, make sure the Xcode license has been agreed-to with "sudo xcodebuild -license"
2. Download the source for the dtrace and AvailabilityVersions projects, which are required dependencies, as well as xnu itself
   

   $ curl -O http://opensource.apple.com/tarballs/dtrace/dtrace-118.tar.gz
   $ curl -O http://opensource.apple.com/tarballs/AvailabilityVersions/AvailabilityVersions-6.tar.gz
   $ curl -O http://opensource.apple.com/tarballs/xnu/xnu-2422.1.72.tar.gz

3. Build and install CTF tools from dtrace
   

   $ tar zxf dtrace-118.tar.gz
   $ cd dtrace-118
   $ mkdir -p obj sym dst
   $ xcodebuild install -target ctfconvert -target ctfdump -target ctfmerge ARCHS="x86_64" SRCROOT=$PWD OBJROOT=$PWD/obj SYMROOT=$PWD/sym DSTROOT=$PWD/dst
   ...
   $ sudo ditto $PWD/dst/usr/local /usr/local
   Password:
   $ cd ..
   

4. Install AvailabilityVersions
   

   $ tar zxf AvailabilityVersions-6.tar.gz
   $ cd AvailabilityVersions-6
   $ mkdir -p dst
   $ make install SRCROOT=$PWD DSTROOT=$PWD/dst
   $ sudo ditto $PWD/dst/usr/local `xcrun -sdk / -show-sdk-path`/usr/local
   $ cd ..
   

5. Build xnu
   

   $ tar zxf xnu-2422.1.72.tar.gz
   $ cd xnu-2422.1.72
   $ make ARCH_CONFIGS=X86_64 KERNEL_CONFIGS=RELEASE

Building xnu for OS X 10.8 Mountain Lion

The OS X kernel source (xnu) has been released for OS X 10.8 Mountain Lion: here

Building xnu requires Xcode and some additional open-source (but not pre-installed) dependencies. You can build xnu manually by doing:

1. Install OS X Mountain Lion and Xcode 4.4
2. Launch Xcode, go to Preferences... > Downloads and install the Command Line Tools
3. Download the source for the dtrace and AvailabilityVersions projects, which are required dependencies, as well as xnu itself
   

   $ curl -O http://opensource.apple.com/tarballs/dtrace/dtrace-96.tar.gz
   $ curl -O http://opensource.apple.com/tarballs/AvailabilityVersions/AvailabilityVersions-4.2.tar.gz
   $ curl -O http://opensource.apple.com/tarballs/xnu/xnu-2050.7.9.tar.gz

4. Build and install CTF tools from dtrace
   

   $ tar zxf dtrace-96.tar.gz
   $ cd dtrace-96
   $ mkdir -p obj sym dst
   $ xcodebuild install -target ctfconvert -target ctfdump -target ctfmerge ARCHS="x86_64" SRCROOT=$PWD OBJROOT=$PWD/obj SYMROOT=$PWD/sym DSTROOT=$PWD/dst
   ...
   $ sudo ditto $PWD/dst/usr/local /usr/local
   Password:
   $ cd ..
   

5. Install AvailabilityVersions
   

   $ tar zxf AvailabilityVersions-4.2.tar.gz
   $ cd AvailabilityVersions-4.2
   $ mkdir -p dst
   $ make install SRCROOT=$PWD DSTROOT=$PWD/dst
   $ sudo ditto $PWD/dst/usr/local /usr/local
   $ cd ..
   

6. Build xnu
   

   $ tar zxf xnu-2050.7.9.tar.gz 
   $ cd xnu-2050.7.9
   $ make ARCH_CONFIGS=X86_64 KERNEL_CONFIGS=RELEASE
   

Update: If you are using Xcode 4.6, add CWARNFLAGS_STD="-Wall" CXXWARNFLAGS_STD="-Wall" to your make(1) invocation to avoid new warnings-as-errors

Building xnu for Mac OS X 10.7

The Mac OS X kernel source (xnu) has been released for Mac OS X 10.7 Lion: here

Building xnu requires some open source (but not pre-installed) tools. Darwinbuild is the most reliable way for building these dependencies and xnu itself. Until that is ready, you can build the tools manually as follows:

1. Download the build tools source(s)
   
   $ curl -s -O http://opensource.apple.com/tarballs/dtrace/dtrace-90.tar.gz
   $ curl -s -O http://opensource.apple.com/tarballs/bootstrap_cmds/bootstrap_cmds-79.tar.gz
   
   
2. Unpack the tools
   
   $ tar zxf dtrace-90.tar.gz
   $ tar zxf bootstrap_cmds-79.tar.gz
   
   
3. Build dtrace
   
   $ cd dtrace-90
   $ mkdir -p obj sym dst
   $ xcodebuild install -target ctfconvert -target ctfdump -target ctfmerge ARCHS="i386 x86_64" SRCROOT=$PWD OBJROOT=$PWD/obj SYMROOT=$PWD/sym DSTROOT=$PWD/dst
   ...
   $ sudo ditto $PWD/dst/usr/local /usr/local
   Password:
   $ cd ..
   
   
4. Build bootstrap_cmds
   
   $ cd bootstrap_cmds-79
   $ mkdir -p obj sym dst
   $ make install RC_ARCHS="i386" SRCROOT=$PWD OBJROOT=$PWD/obj SYMROOT=$PWD/sym DSTROOT=$PWD/dst
   ...
   $ sudo ditto $PWD/dst/usr/local /usr/local
   Password:
   $ cd ..
   
   
5. Download the xnu source
   
   $ curl -s -O http://opensource.apple.com/tarballs/xnu/xnu-1699.22.73.tar.gz
   
   
6. Unpack xnu
   
   $ tar zxf xnu-1699.22.73.tar.gz
   
   
7. Build xnu
   
   $ cd xnu-1699.22.73
   $ make ARCH_CONFIGS="I386 X86_64" KERNEL_CONFIGS="RELEASE"
   ...
   $ file BUILD/obj/RELEASE_*/mach_kernel
   BUILD/obj/RELEASE_I386/mach_kernel: Mach-O executable i386
   BUILD/obj/RELEASE_X86_64/mach_kernel: Mach-O 64-bit executable x86_64