3 B. How to install a new header file from XNU
5 =============================================
10 This builds all the components for kernel, architecture, and machine
11 configurations defined in TARGET_CONFIGS. Additionally, we also support
12 architectures defined in ARCH_CONFIGS and kernel configurations defined in
13 KERNEL_CONFIGS. Note that TARGET_CONFIGS overrides any configurations defined
14 in ARCH_CONFIGS and KERNEL_CONFIGS.
16 By default, architecture defaults to the build machine
17 architecture, and the kernel configuration is set to build for DEVELOPMENT.
19 This will also create a bootable image, mach_kernel, and a kernel binary
20 with symbols, mach_kernel.sys.
23 /* this is all you need to do to build with RELEASE kernel configuration */
24 make TARGET_CONFIGS="release x86_64 default" SDKROOT=/path/to/SDK
26 or the following is equivalent (ommitted SDKROOT will use /)
28 make ARCH_CONFIGS=X86_64
30 2) Building a Component
32 Go to the top directory in your XNU project.
34 If you are using a sh-style shell, run the following command:
37 If you are using a csh-style shell, run the following command:
38 % source SETUP/setup.csh
40 This will define the following environmental variables:
41 SRCROOT, OBJROOT, DSTROOT, SYMROOT
43 From a component top directory:
47 This builds a component for all architectures, kernel configurations, and
48 machine configurations defined in TARGET_CONFIGS (or alternately ARCH_CONFIGS
52 $(OBJROOT)/RELEASE_X86_64/osfmk/RELEASE/osfmk.filelist: list of objects in osfmk component
54 From the component top directory:
58 This includes your component in the bootable image, mach_kernel, and
59 in the kernel binary with symbols, mach_kernel.sys.
61 WARNING: If a component header file has been modified, you will have to do
62 the above procedure 1.
66 Define kernel configuration to DEBUG in your environment or when running a
67 make command. Then, apply procedures 4, 5
69 $ make TARGET_CONFIGS="DEBUG X86_64 DEFAULT" all
73 $ make KERNEL_CONFIGS=DEBUG ARCH_CONFIGS=X86_64 all
77 $ export TARGET_CONFIGS="DEBUG X86_64 DEFAULT"
78 $ export SDKROOT=/path/to/SDK
82 $(OBJROOT)/DEBUG_X86_64/osfmk/DEBUG/osfmk.filelist: list of objects in osfmk component
83 $(OBJROOT)/DEBUG_X86_64/mach_kernel: bootable image
87 Define architectures in your environment or when running a make command.
88 Apply procedures 3, 4, 5
90 $ make TARGET_CONFIGS="RELEASE I386 DEFAULT RELEASE X86_64 DEFAULT" exporthdrs all
94 $ make ARCH_CONFIGS="I386 X86_64" exporthdrs all
98 $ export ARCH_CONFIGS="I386 X86_64"
102 To display complete tool invocations rather than an abbreviated version,
105 6) Debug information formats
106 By default, a DWARF debug information repository is created during the install phase; this is a "bundle" named mach_kernel.dSYM
107 To select the older STABS debug information format (where debug information is embedded in the mach_kernel.sys image), set the BUILD_STABS environment variable.
108 $ export BUILD_STABS=1
111 7) Build check before integration
113 From the top directory, run:
115 $ ~rc/bin/buildit . -arch i386 -arch x86_64 -arch armv7 -arch ppc -noinstallsrc -nosum
118 xnu supports a number of XBS build aliases, which allow B&I to build
119 the same source submission multiple times in different ways, to
120 produce different results. Each build alias supports the standard
121 "clean", "install", "installsrc", "installhdrs" targets, but
122 conditionalize their behavior on the RC_ProjectName make variable
123 which is passed as the -project argument to ~rc/bin/buildit, which
126 -project xnu # the default, builds /mach_kernel, kernel-space
127 # headers, user-space headers, man pages,
130 -project xnu_debug # a DEBUG kernel in /AppleInternal with dSYM
132 -project libkxld # user-space version of kernel linker
134 -project libkmod # static library automatically linked into kexts
136 -project Libsyscall # automatically generate BSD syscall stubs
140 8) Creating tags and cscope
142 Set up your build environment as per instructions in 2a
144 From the top directory, run:
146 $ make tags # this will build ctags and etags on a case-sensitive
147 # volume, only ctags on case-insensitive
149 $ make TAGS # this will build etags
151 $ make cscope # this will build cscope database
153 9) Other makefile options
155 $ make MAKEJOBS=-j8 # this will use 8 processes during the build. The default is 2x the number of active cores
157 $ make -w # trace recursive make invocations. Useful in combination with VERBOSE=YES
159 $ make BUILD_LTO=1 # build with LLVM Link Time Optimization (experimental)
161 $ make BUILD_INTEGRATED_ASSEMBLER=1 # build with LLVM integrated assembler (experimental)
163 =============================================
164 B. How to install a new header file from XNU
166 [Note: This does not cover installing header files in IOKit framework]
168 1) XNU installs header files at the following locations -
169 a. $(DSTROOT)/System/Library/Frameworks/Kernel.framework/Headers
170 b. $(DSTROOT)/System/Library/Frameworks/Kernel.framework/PrivateHeaders
171 c. $(DSTROOT)/System/Library/Frameworks/System.framework/Headers
172 d. $(DSTROOT)/System/Library/Frameworks/System.framework/PrivateHeaders
173 e. $(DSTROOT)/usr/include/
175 Kernel.framework is used by kernel extensions. System.framework
176 and /usr/include are used by user level applications. The header
177 files in framework's "PrivateHeaders" are only available for Apple
178 Internal development.
180 2) The directory containing the header file should have a Makefile that
181 creates the list of files that should be installed at different locations.
182 If you are adding first header file in a directory, you will need to
183 create Makefile similar to xnu/bsd/sys/Makefile.
185 Add your header file to the correct file list depending on where you want
186 to install it. The default locations where the header files are installed
187 from each file list are -
189 a. DATAFILES : To make header file available in user level -
190 $(DSTROOT)/System/Library/Frameworks/System.framework/Headers
191 $(DSTROOT)/System/Library/Frameworks/System.framework/PrivateHeaders
192 $(DSTROOT)/usr/include/
194 b. PRIVATE_DATAFILES : To make header file available to Apple internal in
196 $(DSTROOT)/System/Library/Frameworks/System.framework/PrivateHeaders
198 c. KERNELFILES : To make header file available in kernel level -
199 $(DSTROOT)/System/Library/Frameworks/Kernel.framework/Headers
200 $(DSTROOT)/System/Library/Frameworks/Kernel.framework/PrivateHeaders
202 d. PRIVATE_KERNELFILES : To make header file available to Apple internal
203 for kernel extensions -
204 $(DSTROOT)/System/Library/Frameworks/Kernel.framework/PrivateHeaders
206 3) The Makefile combines the file lists mentioned above into different
207 install lists which are used by build system to install the header files.
209 If the install list that you are interested does not exist, create it
210 by adding the appropriate file lists. The default install lists, its
211 member file lists and their default location are described below -
213 a. INSTALL_MI_LIST : Installs header file to location that is available to
214 everyone in user level.
216 $(DSTROOT)/System/Library/Frameworks/System.framework/Headers
217 $(DSTROOT)/usr/include/
219 INSTALL_MI_LIST = ${DATAFILES}
221 b. INSTALL_MI_LCL_LIST : Installs header file to location that is available
222 for Apple internal in user level.
224 $(DSTROOT)/System/Library/Frameworks/System.framework/PrivateHeaders
226 INSTALL_MI_LCL_LIST = ${DATAFILES} ${PRIVATE_DATAFILES}
228 c. INSTALL_KF_MI_LIST : Installs header file to location that is available
229 to everyone for kernel extensions.
231 $(DSTROOT)/System/Library/Frameworks/Kernel.framework/Headers
233 INSTALL_KF_MI_LIST = ${KERNELFILES}
235 d. INSTALL_KF_MI_LCL_LIST : Installs header file to location that is
236 available for Apple internal for kernel extensions.
238 $(DSTROOT)/System/Library/Frameworks/Kernel.framework/PrivateHeaders
240 INSTALL_KF_MI_LCL_LIST = ${KERNELFILES} ${PRIVATE_KERNELFILES}
242 4) If you want to install the header file in a sub-directory of the paths
243 described in (1), specify the directory name using two variable
244 INSTALL_MI_DIR and EXPORT_MI_DIR as follows -
246 INSTALL_MI_DIR = dirname
247 EXPORT_MI_DIR = dirname
249 5) A single header file can exist at different locations using the steps
250 mentioned above. However it might not be desirable to make all the code
251 in the header file available at all the locations. For example, you
252 want to export a function only to kernel level but not user level.
254 You can use C language's pre-processor directive (#ifdef, #endif, #ifndef)
255 to control the text generated before a header file is installed. The kernel
256 only includes the code if the conditional macro is TRUE and strips out
257 code for FALSE conditions from the header file.
259 Some pre-defined macros and their descriptions are -
260 a. PRIVATE : If true, code is available to all of the xnu kernel and is
261 not available in kernel extensions and user level header files. The
262 header files installed in all the paths described above in (1) will not
263 have code enclosed within this macro.
265 b. KERNEL_PRIVATE : Same as PRIVATE
267 c. BSD_KERNEL_PRIVATE : If true, code is available to the xnu/bsd part of
268 the kernel and is not available to rest of the kernel, kernel extensions
269 and user level header files. The header files installed in all the
270 paths described above in (1) will not have code enclosed within this
273 d. KERNEL : If true, code is available only in kernel and kernel
274 extensions and is not available in user level header files. Only the
275 header files installed in following paths will have the code -
276 $(DSTROOT)/System/Library/Frameworks/Kernel.framework/Headers
277 $(DSTROOT)/System/Library/Frameworks/Kernel.framework/PrivateHeaders