README

   1 Table of contents:
   2 A. How to build XNU
   3 B. How to install a new header file from XNU
   4
   5 =============================================
   6 A. How to build XNU:
   7
   8 1) Type: "make"
   9
  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.
  15
  16   By default, architecture defaults to the build machine
  17   architecture, and the kernel configuration is set to build for DEVELOPMENT.
  18
  19   This will also create a bootable image, mach_kernel,  and a kernel binary
  20   with symbols, mach_kernel.sys.
  21
  22
  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
  25
  26         or the following is equivalent (ommitted SDKROOT will use /)
  27
  28         make ARCH_CONFIGS=X86_64
  29
  30 2) Building DEBUG
  31
  32   Define kernel configuration to DEBUG in your environment or when running a
  33   make command.  Then, apply procedures 4, 5
  34
  35   $ make TARGET_CONFIGS="DEBUG X86_64 DEFAULT" all
  36
  37   or
  38
  39   $ make KERNEL_CONFIGS=DEBUG ARCH_CONFIGS=X86_64 all
  40
  41   or
  42
  43   $ export TARGET_CONFIGS="DEBUG X86_64 DEFAULT"
  44   $ export SDKROOT=/path/to/SDK
  45   $ make all
  46
  47   Example:
  48     $(OBJROOT)/DEBUG_X86_64/osfmk/DEBUG/osfmk.filelist: list of objects in osfmk component
  49     $(OBJROOT)/DEBUG_X86_64/mach_kernel: bootable image
  50
  51 3) Building fat
  52
  53   Define architectures in your environment or when running a make command.
  54   Apply procedures 3, 4, 5
  55
  56   $ make TARGET_CONFIGS="RELEASE I386 DEFAULT RELEASE X86_64 DEFAULT" exporthdrs all
  57
  58   or
  59
  60   $ make ARCH_CONFIGS="I386 X86_64" exporthdrs all
  61
  62   or
  63
  64   $ export ARCH_CONFIGS="I386 X86_64"
  65   $ make exporthdrs all
  66
  67 4) Verbose make
  68    To display complete tool invocations rather than an abbreviated version,
  69    $ make VERBOSE=YES
  70
  71 5) Debug information formats
  72    By default, a DWARF debug information repository is created during the install phase; this is a "bundle" named mach_kernel.dSYM
  73    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.
  74    $ export BUILD_STABS=1
  75    $ make
  76
  77 6) Build check before integration
  78
  79   From the top directory, run:
  80
  81     $ ~rc/bin/buildit . -arch i386 -arch x86_64 -arch armv7 -arch ppc -noinstallsrc -nosum
  82
  83
  84   xnu supports a number of XBS build aliases, which allow B&I to build
  85   the same source submission multiple times in different ways, to
  86   produce different results. Each build alias supports the standard
  87   "clean", "install", "installsrc", "installhdrs" targets, but
  88   conditionalize their behavior on the RC_ProjectName make variable
  89   which is passed as the -project argument to ~rc/bin/buildit, which
  90   can be one of:
  91
  92   -project xnu          # the default, builds /mach_kernel, kernel-space
  93                         # headers, user-space headers, man pages,
  94                         # symbol-set kexts
  95
  96   -project xnu_debug    # a DEBUG kernel in /AppleInternal with dSYM
  97
  98   -project libkxld      # user-space version of kernel linker
  99
 100   -project libkmod      # static library automatically linked into kexts
 101
 102   -project Libsyscall   # automatically generate BSD syscall stubs
 103
 104   -project xnu_quick_test # install xnu unit tests
 105
 106
 107
 108 7) Creating tags and cscope
 109
 110   Set up your build environment as per instructions in 2a
 111
 112   From the top directory, run:
 113
 114     $ make tags         # this will build ctags and etags on a case-sensitive
 115                         # volume, only ctags on case-insensitive
 116
 117     $ make TAGS         # this will build etags
 118
 119     $ make cscope       # this will build cscope database
 120
 121 8) Other makefile options
 122
 123    $ make MAKEJOBS=-j8    # this will use 8 processes during the build. The default is 2x the number of active CPUS.
 124    $ make -j8             # the standard command-line option is also accepted
 125
 126    $ make -w              # trace recursive make invocations. Useful in combination with VERBOSE=YES
 127
 128    $ make BUILD_LTO=1     # build with LLVM Link Time Optimization (experimental)
 129
 130    $ make REMOTEBUILD=user@remotehost # perform build on remote host
 131
 132 =============================================
 133 B. How to install a new header file from XNU
 134
 135 [Note: This does not cover installing header files in IOKit framework]
 136
 137 1) XNU installs header files at the following locations -
 138         a. $(DSTROOT)/System/Library/Frameworks/Kernel.framework/Headers
 139         b. $(DSTROOT)/System/Library/Frameworks/Kernel.framework/PrivateHeaders
 140         c. $(DSTROOT)/System/Library/Frameworks/System.framework/Headers
 141         d. $(DSTROOT)/System/Library/Frameworks/System.framework/PrivateHeaders
 142         e. $(DSTROOT)/usr/include/
 143
 144         Kernel.framework is used by kernel extensions.  System.framework
 145         and /usr/include are used by user level applications.  The header
 146         files in framework's "PrivateHeaders" are only available for Apple
 147         Internal development.
 148
 149 2) The directory containing the header file should have a Makefile that
 150    creates the list of files that should be installed at different locations.
 151    If you are adding first header file in a directory, you will need to
 152    create Makefile similar to xnu/bsd/sys/Makefile.
 153
 154    Add your header file to the correct file list depending on where you want
 155    to install it.   The default locations where the header files are installed
 156    from each file list are -
 157
 158    a. DATAFILES : To make header file available in user level -
 159           $(DSTROOT)/System/Library/Frameworks/System.framework/Headers
 160           $(DSTROOT)/System/Library/Frameworks/System.framework/PrivateHeaders
 161           $(DSTROOT)/usr/include/
 162
 163    b. PRIVATE_DATAFILES : To make header file available to Apple internal in
 164       user level -
 165           $(DSTROOT)/System/Library/Frameworks/System.framework/PrivateHeaders
 166
 167    c. KERNELFILES : To make header file available in kernel level -
 168           $(DSTROOT)/System/Library/Frameworks/Kernel.framework/Headers
 169           $(DSTROOT)/System/Library/Frameworks/Kernel.framework/PrivateHeaders
 170
 171    d. PRIVATE_KERNELFILES : To make header file available to Apple internal
 172       for kernel extensions -
 173           $(DSTROOT)/System/Library/Frameworks/Kernel.framework/PrivateHeaders
 174
 175 3) The Makefile combines the file lists mentioned above into different
 176    install lists which are used by build system to install the header files.
 177
 178    If the install list that you are interested does not exist, create it
 179    by adding the appropriate file lists.  The default install lists, its
 180    member file lists and their default location are described below -
 181
 182    a. INSTALL_MI_LIST : Installs header file to location that is available to
 183       everyone in user level.
 184       Locations -
 185           $(DSTROOT)/System/Library/Frameworks/System.framework/Headers
 186           $(DSTROOT)/usr/include/
 187       Definition -
 188           INSTALL_MI_LIST = ${DATAFILES}
 189
 190    b. INSTALL_MI_LCL_LIST : Installs header file to location that is available
 191       for Apple internal in user level.
 192       Locations -
 193           $(DSTROOT)/System/Library/Frameworks/System.framework/PrivateHeaders
 194       Definition -
 195           INSTALL_MI_LCL_LIST = ${DATAFILES} ${PRIVATE_DATAFILES}
 196
 197    c. INSTALL_KF_MI_LIST : Installs header file to location that is available
 198       to everyone for kernel extensions.
 199       Locations -
 200           $(DSTROOT)/System/Library/Frameworks/Kernel.framework/Headers
 201       Definition -
 202           INSTALL_KF_MI_LIST = ${KERNELFILES}
 203
 204    d. INSTALL_KF_MI_LCL_LIST : Installs header file to location that is
 205       available for Apple internal for kernel extensions.
 206       Locations -
 207           $(DSTROOT)/System/Library/Frameworks/Kernel.framework/PrivateHeaders
 208       Definition -
 209           INSTALL_KF_MI_LCL_LIST = ${KERNELFILES} ${PRIVATE_KERNELFILES}
 210
 211 4) If you want to install the header file in a sub-directory of the paths
 212    described in (1), specify the directory name using two variable
 213    INSTALL_MI_DIR and EXPORT_MI_DIR as follows -
 214
 215    INSTALL_MI_DIR = dirname
 216    EXPORT_MI_DIR = dirname
 217
 218 5) A single header file can exist at different locations using the steps
 219    mentioned above.  However it might not be desirable to make all the code
 220    in the header file available at all the locations.  For example, you
 221    want to export a function only to kernel level but not user level.
 222
 223    You can use C language's pre-processor directive (#ifdef, #endif, #ifndef)
 224    to control the text generated before a header file is installed.  The kernel
 225    only includes the code if the conditional macro is TRUE and strips out
 226    code for FALSE conditions from the header file.
 227
 228    Some pre-defined macros and their descriptions are -
 229    a. PRIVATE : If true, code is available to all of the xnu kernel and is
 230       not available in kernel extensions and user level header files.  The
 231       header files installed in all the paths described above in (1) will not
 232       have code enclosed within this macro.
 233
 234    b. KERNEL_PRIVATE : Same as PRIVATE
 235
 236    c. BSD_KERNEL_PRIVATE : If true, code is available to the xnu/bsd part of
 237       the kernel and is not available to rest of the kernel, kernel extensions
 238       and user level header files.  The header files installed in all the
 239       paths described above in (1) will not have code enclosed within this
 240       macro.
 241
 242    d. KERNEL :  If true, code is available only in kernel and kernel
 243       extensions and is not available in user level header files.  Only the
 244       header files installed in following paths will have the code -
 245           $(DSTROOT)/System/Library/Frameworks/Kernel.framework/Headers
 246           $(DSTROOT)/System/Library/Frameworks/Kernel.framework/PrivateHeaders