Building for Intel-based Mac computers

The Intel side of your I/O Kit KEXT must be built using GCC 4.0 and the Mac OS X 10.4u (Universal) SDK or later. Use the SDK representing the oldest version of Mac OS X you wish to support, keeping in mind that the first version of Mac OS X to be shipped on Intel-based systems was Mac OS X 10.4.4.

Building for PowerPC-based Mac computers

The PowerPC side of your KEXT should be built using the Mac OS X SDK representing the oldest version of Mac OS X you wish to support.

Xcode 2.x Build Settings

Using the proper SDK and compiler versions is easily accomplished using Xcode's per-architecture build settings.

1. Set Architectures to ppc i386. This can be done by double-clicking the word Architectures and then selecting both the PowerPC and Intel checkboxes.

2. Remove any setting for SDK Path and VALID_ARCHS by selecting the option and then clicking the - button at the bottom of the window.

3. Add the custom settings SDKROOT_i386 and SDKROOT_ppc. Set the value of each to the path of the SDK to use to build on each architecture. SDKROOT_i386 should be set to /Developer/SDKs/MacOSX10.4u.sdk and SDKROOT_ppc should point to the SDK matching the oldest major Mac OS X release you wish to support, such as /Developer/SDKs/MacOSX10.2.8.sdk.

4. Add the settings GCC_VERSION_i386 and GCC_VERSION_ppc that specify the compiler version to use when building for each architecture. GCC_VERSION_i386 must be set to 4.0 or greater. If you want to support versions of Mac OS X prior to 10.4, GCC_VERSION_ppc must be set to 3.3.

5. If you are using Xcode 2.4, 2.4.1, or 2.5, and the PowerPC side of your KEXT is targeting Mac OS X 10.4.x, add the setting PER_ARCH_CFLAGS_ppc that specifies compiler flags to pass to GCC only when building for the PowerPC architecture. Set the value of PER_ARCH_CFLAGS_ppc to -DKPI_10_4_0_PPC_COMPAT.

6. Set Mac OS X Deployment Target to Compiler Default.

7. Add the settings MACOSX_DEPLOYMENT_TARGET_i386 and MACOSX_DEPLOYMENT_TARGET_ppc. These settings must have the value of a major Mac OS X release version number such as 10.2 or 10.4. Do not specify software update versions such as 10.3.9. MACOSX_DEPLOYMENT_TARGET_i386 must be set to 10.4 or later, and MACOSX_DEPLOYMENT_TARGET_ppc should be set to the oldest major Mac OS X release you wish to support.

Xcode 3.0 Build Settings

Xcode 3.0 provides an improved user interface for per-architecture build settings over Xcode 2.x.

1. Set the Configuration menu at the top of the window to All Configurations.

2. Single click the value of the build setting Architectures and change it to i386 ppc.

3. Set Base SDK to /Developer/SDKs/MacOSX10.4u.sdk if the Intel side of your KEXT is targeting Mac OS X 10.4 or /Developer/SDKs/MacOSX10.5.sdk if targeting Mac OS X 10.5.

   If you want to use a different SDK when building for the PowerPC architecture, select the Base SDK build setting, then select Add Per-Architecture Setting For from the action menu at the lower left corner of the window and select PowerPC from the submenu. Change the value of the PowerPC setting just added to the path of the desired SDK for the PowerPC architecture, such as /Developer/SDKs/MacOSX10.3.9.sdk.

4. Set Debug Information Format to DWARF with dSYM File.

   If you need to use GCC 3.3 when building for the PowerPC architecture, select the Debug Information Format build setting, then select Add Per-Architecture Setting For from the action menu at the lower left corner of the window and select PowerPC from the submenu. Change the PowerPC setting just added to Stabs using the popup menu to the right.

5. Add the user-defined setting GCC_VERSION and set its value to 4.0.

   If you want to support versions of Mac OS X prior to 10.4 when building for the PowerPC architecture, select the GCC_VERSION build setting, then select Add Per-Architecture Setting For from the action menu at the lower left corner of the window and select PowerPC from the submenu. Change the value of the PowerPC setting just added to 3.3.

6. Set Mac OS X Deployment Target to Mac OS X 10.4 or later.

   If you want to support versions of Mac OS X prior to 10.4 when building for the PowerPC architecture, select the Mac OS X Deployment Target build setting, then select Add Per-Architecture Setting For from the action menu at the lower left corner of the window and select PowerPC from the submenu. Change the value of the PowerPC setting just added to the oldest major Mac OS X release you wish to support using the popup menu to the right.

7. If the PowerPC side of your KEXT is targeting Mac OS X 10.4.x, select the Other C Flags build setting, then select Add Per-Architecture Setting For from the action menu at the lower left corner of the window and select PowerPC from the submenu. Change the value of the PowerPC setting just added to -DKPI_10_4_0_PPC_COMPAT.

Xcode 3.1 Build Settings

Xcode 3.1 uses conditional build settings in place of the per-architecture build settings used by Xcode 2.x and 3.0.

To convert a PowerPC-only Xcode I/O Kit driver project to a universal project, first make sure that all targets in your project are native Xcode targets. You can check this by opening your project in Xcode, then select the Project menu and see if the command Upgrade All Targets in Project to Native is enabled. If it is, make a backup copy of your project, then use that command to convert all of your legacy targets to native.

Then, make the following changes to the Project or Target Build settings. Modify the Project settings if you want the settings to apply to all targets in the project. Modify the Target settings if you want just a particular target to produce a universal KEXT.

1. Set the Configuration menu at the top of the window to All Configurations.

2. Set Architectures to Standard (32-bit Universal).

3. Set Base SDK to 10.4 or later.

   If you want to use a different SDK when building for the PowerPC architecture, select the Base SDK build setting, then select Add Build Setting Condition from the action menu at the lower left corner of the window. Change the Any Architecture setting to PowerPC and select the desired SDK for the PowerPC architecture from the popup menu to the right.

4. Uncheck the Build Active Architecture Only checkbox.

5. Set Debug Information Format to DWARF with dSYM File.

   If you need to use GCC 3.3 when building for the PowerPC architecture, select the Debug Information Format build setting, then select Add Build Setting Condition from the action menu at the lower left corner of the window. Change the Any Architecture setting to PowerPC and select Stabs from the popup menu to the right.

6. Set C/C++ Compiler Version to GCC System Version (4.0).

   If you want to support versions of Mac OS X prior to 10.4 when building for the PowerPC architecture, select the C/C++ Compiler Version build setting, then select Add Build Setting Condition from the action menu at the lower left corner of the window. Change the Any Architecture setting to PowerPC and select GCC 3.3 from the popup menu to the right.

7. Set Deployment Target to Mac OS X 10.4 or later.

   If you want to support versions of Mac OS X prior to 10.4 when building for the PowerPC architecture, select the Deployment Target build setting, then select Add Build Setting Condition from the action menu at the lower left corner of the window. Change the Any Architecture setting to PowerPC and select the oldest major Mac OS X release you wish to support from the popup menu to the right.

8. Check the Kernel Development Mode checkbox.

9. If the PowerPC side of your KEXT is targeting Mac OS X 10.4.x, select the Other C Flags build setting, then select Add Build Setting Condition from the action menu at the lower left corner of the window. Change the Any Architecture setting to PowerPC and set the value to the right to -DKPI_10_4_0_PPC_COMPAT.