Lines Matching +full:built +full:- +full:in
16 kbuild Makefiles exist in every subdirectory
29 architecture-specific information to the top Makefile.
34 any built-in or modular targets.
51 working on. In order to do this effectively, they need some overall
69 kbuild infrastructure. This chapter introduces the syntax used in the
80 ----------------
83 These lines define the files to be built, any special compilation
90 obj-y += foo.o
92 This tells kbuild that there is one object in that directory, named
93 foo.o. foo.o will be built from foo.c or foo.S.
95 If foo.o shall be built as a module, the variable obj-m is used.
100 obj-$(CONFIG_FOO) += foo.o
102 $(CONFIG_FOO) evaluates to either y (for built-in) or m (for module).
106 Built-in object goals - obj-y
107 -----------------------------
110 in the $(obj-y) lists. These lists depend on the kernel
113 Kbuild compiles all the $(obj-y) files. It then calls
114 ``$(AR) rcSTP`` to merge these files into one built-in.a file.
116 linked into vmlinux by scripts/link-vmlinux.sh
118 The order of files in $(obj-y) is significant. Duplicates in
120 built-in.a and succeeding instances will be ignored.
123 (module_init() / __initcall) will be called during boot in the
124 order they appear. So keep in mind that changing the link
125 order may e.g. change the order in which your SCSI
133 obj-$(CONFIG_ISDN_I4L) += isdn.o
134 obj-$(CONFIG_ISDN_PPP_BSDCOMP) += isdn_bsdcomp.o
136 Loadable module goals - obj-m
137 -----------------------------
139 $(obj-m) specifies object files which are built as loadable
142 A module may be built from one source file or several source
143 files. In the case of one source file, the kbuild makefile
144 simply adds the file to $(obj-m).
149 obj-$(CONFIG_ISDN_PPP_BSDCOMP) += isdn_bsdcomp.o
151 Note: In this example $(CONFIG_ISDN_PPP_BSDCOMP) evaluates to "m"
153 If a kernel module is built from several source files, you specify
154 that you want to build a module in the same way as above; however,
156 module from, so you have to tell it by setting a $(<module_name>-y)
162 obj-$(CONFIG_ISDN_I4L) += isdn.o
163 isdn-y := isdn_net_lib.o isdn_v110.o isdn_common.o
165 In this example, the module name will be isdn.o. Kbuild will
166 compile the objects listed in $(isdn-y) and then run
167 ``$(LD) -r`` on the list of these files to generate isdn.o.
169 Due to kbuild recognizing $(<module_name>-y) for composite objects,
176 obj-$(CONFIG_EXT2_FS) += ext2.o
177 ext2-y := balloc.o dir.o file.o ialloc.o inode.o ioctl.o \
179 ext2-$(CONFIG_EXT2_FS_XATTR) += xattr.o xattr_user.o \
182 In this example, xattr.o, xattr_user.o and xattr_trusted.o are only
189 parts and then link this into built-in.a, as you would expect.
191 Library file goals - lib-y
192 --------------------------
194 Objects listed with obj-* are used for modules, or
195 combined in a built-in.a for that specific directory.
197 be included in a library, lib.a.
198 All objects listed with lib-y are combined in a single
200 Objects that are listed in obj-y and additionally listed in
201 lib-y will not be included in the library, since they will
203 For consistency, objects listed in lib-m will be included in lib.a.
205 Note that the same kbuild makefile may list files to be built-in
207 may contain both a built-in.a and a lib.a file.
212 lib-y := delay.o
215 actually recognize that there is a lib.a being built, the directory
216 shall be listed in libs-y.
220 Use of lib-y is normally restricted to ``lib/`` and ``arch/*/lib``.
222 Descending down in directories
223 ------------------------------
225 A Makefile is only responsible for building objects in its own
226 directory. Files in subdirectories should be taken care of by
227 Makefiles in these subdirs. The build system will automatically
228 invoke make recursively in subdirectories, provided you let it know of
231 To do so, obj-y and obj-m are used.
232 ext2 lives in a separate directory, and the Makefile present in fs/
238 obj-$(CONFIG_EXT2_FS) += ext2/
240 If CONFIG_EXT2_FS is set to either "y" (built-in) or "m" (modular)
241 the corresponding obj- variable will be set, and kbuild will descend
242 down in the ext2 directory.
248 When Kbuild descends into the directory with "y", all built-in objects
249 from that directory are combined into the built-in.a, which will be
252 When Kbuild descends into the directory with "m", in contrast, nothing
253 from that directory will be linked into vmlinux. If the Makefile in
254 that directory specifies obj-y, those objects will be left orphan.
255 It is very likely a bug of the Makefile or of dependencies in Kconfig.
257 Kbuild also supports dedicated syntax, subdir-y and subdir-m, for
259 do not contain kernel-space objects at all. A typical usage is to let
265 subdir-$(CONFIG_GCC_PLUGINS) += gcc-plugins
266 subdir-$(CONFIG_MODVERSIONS) += genksyms
267 subdir-$(CONFIG_SECURITY_SELINUX) += selinux
269 Unlike obj-y/m, subdir-y/m does not need the trailing slash since this
276 Non-builtin vmlinux targets - extra-y
277 -------------------------------------
279 extra-y specifies targets which are needed for building vmlinux,
280 but not combined into built-in.a.
292 extra-y += vmlinux.lds
294 $(extra-y) should only contain targets needed for vmlinux.
296 Kbuild skips extra-y when vmlinux is apparently not a final goal.
299 If you intend to build targets unconditionally, always-y (explained
300 in the next section) is the correct syntax to use.
302 Always built goals - always-y
303 -----------------------------
305 always-y specifies targets which are literally always built when
311 offsets-file := include/generated/asm-offsets.h
312 always-y += $(offsets-file)
315 -----------------
317 ccflags-y, asflags-y and ldflags-y
318 These three flags apply only to the kbuild makefile in which they
325 ccflags-y specifies options for compiling with $(CC).
330 ccflags-y := -Os -D_LINUX -DBUILDING_ACPICA
331 ccflags-$(CONFIG_ACPI_DEBUG) += -DACPI_DEBUG_OUTPUT
337 asflags-y specifies assembler options.
342 asflags-y := -ansi
344 ldflags-y specifies options for linking with $(LD).
349 ldflags-y += -T $(srctree)/$(src)/decompress_$(arch-y).lds
351 subdir-ccflags-y, subdir-asflags-y
352 The two flags listed above are similar to ccflags-y and asflags-y.
353 The difference is that the subdir- variants have effect for the kbuild
355 Options specified using subdir-* are added to the commandline before
356 the options specified using the non-subdir variants.
360 subdir-ccflags-y := -Werror
362 ccflags-remove-y, asflags-remove-y
368 ccflags-remove-$(CONFIG_MCOUNT) += -pg
371 CFLAGS_$@ and AFLAGS_$@ only apply to commands in current
374 $(CFLAGS_$@) specifies per-file options for $(CC). The $@
377 CFLAGS_$@ has the higher priority than ccflags-remove-y; CFLAGS_$@
378 can re-add compiler flags that were removed by ccflags-remove-y.
383 CFLAGS_aha152x.o = -DAHA152X_STAT -DAUTOCONF
387 $(AFLAGS_$@) is a similar feature for source files in assembly
390 AFLAGS_$@ has the higher priority than asflags-remove-y; AFLAGS_$@
391 can re-add assembler flags that were removed by asflags-remove-y.
396 AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
397 AFLAGS_crunch-bits.o := -Wa,-mcpu=ep9312
398 AFLAGS_iwmmxt.o := -Wa,-mcpu=iwmmxt
401 -------------------
406 2) ``CONFIG_`` options used in all prerequisite files
407 3) Command-line used to compile target
410 be re-compiled.
413 ------------
418 Another example are the architecture-specific Makefiles which
422 Kbuild is not executing in the directory where the Makefile is
431 referring to files located in the src tree.
442 $(CPP) -DCHIP=810 - < $< | ... $(src)/script_asm.pl
453 echoing information to user in a rule is often a good practice
454 but when execution ``make -s`` one does not expect to see any output
457 text following $(kecho) to stdout except if ``make -s`` is used.
471 quiet_cmd_<command> - what shall be echoed
472 cmd_<command> - the command to execute
490 ------------------------
498 Kbuild achieves this by a kind of meta-programming.
500 if_changed is the macro used for this purpose, in the following form::
508 Any target that utilizes if_changed must be listed in $(targets),
510 always be built.
512 If the target is already listed in the recognized syntax such as
513 obj-y/m, lib-y/m, extra-y/m, always-y/m, hostprogs, userprogs, Kbuild
518 used in conjunction with custom rules as defined in `Custom Rules`_.
530 It stores the executed command in a corresponding .cmd
531 file and multiple calls would result in overwrites and
536 -----------------------
538 The kernel may be built with several different versions of
544 as-option
545 as-option is used to check if $(CC) -- when used to compile
546 assembler (``*.S``) files -- supports the given option. An optional
552 cflags-y += $(call as-option,-Wa$(comma)-isa=$(isa-y),)
554 In the above example, cflags-y will be assigned the option
555 -Wa$(comma)-isa=$(isa-y) if it is supported by $(CC).
559 as-instr
560 as-instr checks if the assembler reports a specific instruction
562 C escapes are supported in the test instruction
563 Note: as-instr-option uses KBUILD_AFLAGS for assembler options
565 cc-option
566 cc-option is used to check if $(CC) supports a given option, and if
572 cflags-y += $(call cc-option,-march=pentium-mmx,-march=i586)
574 In the above example, cflags-y will be assigned the option
575 -march=pentium-mmx if supported by $(CC), otherwise -march=i586.
576 The second argument to cc-option is optional, and if omitted,
577 cflags-y will be assigned no value if first option is not supported.
578 Note: cc-option uses KBUILD_CFLAGS for $(CC) options
580 cc-option-yn
581 cc-option-yn is used to check if gcc supports a given option
587 biarch := $(call cc-option-yn, -m32)
588 aflags-$(biarch) += -a32
589 cflags-$(biarch) += -m32
591 In the above example, $(biarch) is set to y if $(CC) supports the -m32
592 option. When $(biarch) equals "y", the expanded variables $(aflags-y)
593 and $(cflags-y) will be assigned the values -a32 and -m32,
596 Note: cc-option-yn uses KBUILD_CFLAGS for $(CC) options
598 cc-disable-warning
599 cc-disable-warning checks if gcc supports a given warning and returns
601 because gcc 4.4 and later accept any unknown -Wno-* option and only
602 warn about it if there is another warning in the source file.
606 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
608 In the above example, -Wno-unused-but-set-variable will be added to
611 gcc-min-version
612 gcc-min-version tests if the value of $(CONFIG_GCC_VERSION) is greater than
617 cflags-$(call gcc-min-version, 70100) := -foo
619 In this example, cflags-y will be assigned the value -foo if $(CC) is gcc and
622 clang-min-version
623 clang-min-version tests if the value of $(CONFIG_CLANG_VERSION) is greater
628 cflags-$(call clang-min-version, 110000) := -foo
630 In this example, cflags-y will be assigned the value -foo if $(CC) is clang
633 cc-cross-prefix
634 cc-cross-prefix is used to check if there exists a $(CC) in path with
636 prefix$(CC) in the PATH is returned - and if no prefix$(CC) is found
639 Additional prefixes are separated by a single space in the
640 call of cc-cross-prefix.
643 to set CROSS_COMPILE to well-known values but may have several
655 CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu-)
660 -----------------------
662 ld-option
663 ld-option is used to check if $(LD) supports the supplied option.
664 ld-option takes two options as arguments.
672 LDFLAGS_vmlinux += $(call ld-option, -X)
675 -----------------
700 Two steps are required in order to use a host executable.
706 This can be done in two ways. Either add the dependency in a rule,
707 or utilise the variable ``always-y``.
708 Both possibilities are described in the following.
711 -------------------
713 In some cases there is a need to compile and run a program on the
717 built on the build host.
723 Kbuild assumes in the above example that bin2hex is made from a single
724 c-source file named bin2hex.c located in the same directory as
728 -----------------------
733 $(<executable>-objs) lists all objects used to link the final
740 lxdialog-objs := checklist.o lxdialog.o
743 files. In the above example, checklist.c is compiled to checklist.o
747 Note: The syntax <executable>-y is not permitted for host-programs.
750 ---------------------------
752 kbuild offers support for host programs written in C++. This was
760 qconf-cxxobjs := qconf.o
762 In the example above the executable is composed of the C++ file
763 qconf.cc - identified by $(qconf-cxxobjs).
772 qconf-cxxobjs := qconf.o
773 qconf-objs := check.o
776 ----------------------------
778 Kbuild offers support for host programs written in Rust. However,
780 it may only be used in scenarios where Rust is required to be
786 target-rust := y
789 located in the same directory as the ``Makefile``. The crate may
793 ----------------------------------------------
797 the options specified in $(KBUILD_HOSTCFLAGS).
800 in that Makefile, use the variable HOST_EXTRACFLAGS.
805 HOST_EXTRACFLAGS += -I/usr/include/ncurses
813 HOSTCFLAGS_piggyback.o := -DKERNELBASE=$(KERNELBASE)
820 HOSTLDLIBS_qconf := -L$(QTDIR)/lib
823 ``-L$(QTDIR)/lib``.
825 When host programs are actually built
826 -------------------------------------
828 Kbuild will only build host-programs when they are referenced
831 This is possible in two ways:
833 (1) List the prerequisite explicitly in a custom rule.
838 hostprogs := gen-devlist
839 $(obj)/devlist.h: $(src)/pci.ids $(obj)/gen-devlist
840 ( cd $(obj); ./gen-devlist ) < $<
842 The target $(obj)/devlist.h will not be built before
843 $(obj)/gen-devlist is updated. Note that references to
844 the host programs in custom rules must be prefixed with $(obj).
846 (2) Use always-y
849 shall be built when a makefile is entered, the always-y
856 always-y := $(hostprogs)
860 hostprogs-always-y := lxdialog
862 This will tell kbuild to build lxdialog even if not referenced in
876 ------------------------
878 The following line tells kbuild that the program bpf-direct shall be
879 built for the target architecture.
883 userprogs := bpf-direct
885 Kbuild assumes in the above example that bpf-direct is made from a
886 single C source file named bpf-direct.c located in the same directory
890 ----------------------------
895 $(<executable>-objs) lists all objects used to link the final
901 userprogs := bpf-fancy
902 bpf-fancy-objs := bpf-fancy.o bpf-helper.o
905 files. In the above example, bpf-fancy.c is compiled to bpf-fancy.o
906 and bpf-helper.c is compiled to bpf-helper.o.
908 Finally, the two .o files are linked to the executable, bpf-fancy.
909 Note: The syntax <executable>-y is not permitted for userspace programs.
912 ---------------------------------------------------
916 the options specified in $(KBUILD_USERCFLAGS).
919 in that Makefile, use the variable userccflags.
924 userccflags += -I usr/include
931 bpf-helper-userccflags += -I user/include
938 bpfilter_umh-userldflags += -static
940 When linking bpfilter_umh, it will be passed the extra option -static.
944 When userspace programs are actually built
945 ------------------------------------------
958 $(obj)/bpfilter_umh is built before $(obj)/bpfilter_umh_blob.o
960 (2) Use always-y
965 always-y := $(userprogs)
969 userprogs-always-y := binderfs_example
977 ``make clean`` deletes most generated files in the obj tree where the kernel
979 Kbuild knows targets listed in $(hostprogs), $(always-y), $(always-m),
980 $(always-), $(extra-y), $(extra-) and $(targets). They are all deleted
985 Additional files or directories can be specified in kbuild makefiles by use of
986 $(clean-files).
991 clean-files := crc32table.h
994 Kbuild will assume files to be in the same relative directory as the
998 $(no-clean-files) variable.
1000 Usually kbuild descends down in subdirectories due to ``obj-* := dir/``,
1001 but in the architecture makefiles where the kbuild infrastructure
1007 subdir- := compressed
1009 The above assignment instructs kbuild to descend down in the
1012 Note 1: arch/$(SRCARCH)/Makefile cannot use ``subdir-``, because that file is
1013 included in the top level makefile. Instead, arch/$(SRCARCH)/Kbuild can use
1014 ``subdir-``.
1016 Note 2: All directories listed in core-y, libs-y, drivers-y and net-y will
1023 before starting to descend down in the individual directories.
1036 2) Store kernel version in include/linux/version.h
1040 - Additional prerequisites are specified in arch/$(SRCARCH)/Makefile
1042 4) Recursively descend down in all directories listed in
1043 init-* core* drivers-* net-* libs-* and build all targets.
1045 - The values of the above variables are expanded in arch/$(SRCARCH)/Makefile.
1049 The very first objects linked are listed in scripts/head-object-list.txt.
1051 6) Finally, the architecture-specific part does any required post processing
1054 - This includes building boot records
1055 - Preparing initrd images and the like
1058 ----------------------------------------------------
1069 KBUILD_LDFLAGS := -m elf_s390
1071 Note: ldflags-y can be used to further customise
1072 the flags used. See `Non-builtin vmlinux targets - extra-y`_.
1085 LDFLAGS_vmlinux := -e stext
1091 the flags specified in OBJCOPYFLAGS will be used.
1099 OBJCOPYFLAGS := -O binary
1105 In this example, the binary $(obj)/image is a binary version of
1111 Default value - see top level Makefile.
1118 KBUILD_AFLAGS += -m64 -mcpu=ultrasparc
1123 Default value - see top level Makefile.
1132 cflags-$(CONFIG_X86_32) := -march=i386
1133 cflags-$(CONFIG_X86_64) := -mcmodel=small
1134 KBUILD_CFLAGS += $(cflags-y)
1142 cflags-$(CONFIG_MPENTIUMII) += $(call cc-option,\
1143 -march=pentium2,-march=i686)
1145 # Disable unit-at-a-time mode ...
1146 KBUILD_CFLAGS += $(call cc-option,-fno-unit-at-a-time)
1156 Default value - see top level Makefile.
1162 Note that target specification file generation (for ``--target``)
1163 is handled in ``scripts/generate_rust_target.rs``.
1166 Assembler options specific for built-in
1174 $(KBUILD_AFLAGS_MODULE) is used to add arch-specific options that
1180 $(CC) options specific for built-in
1188 $(KBUILD_CFLAGS_MODULE) is used to add arch-specific options that
1194 $(RUSTC) options specific for built-in
1202 $(KBUILD_RUSTFLAGS_MODULE) is used to add arch-specific options that
1210 $(KBUILD_LDFLAGS_MODULE) is used to add arch-specific options
1216 The linker script with full path. Assigned by the top-level Makefile.
1219 All object files for vmlinux. They are linked to vmlinux in the same
1220 order as listed in KBUILD_VMLINUX_OBJS.
1222 The objects listed in scripts/head-object-list.txt are exceptions;
1231 --------------------------------
1240 --------------------------------
1243 built before starting to descend down in the subdirectories.
1252 In this example, the file target maketools will be processed
1253 before descending down in the subdirectories.
1255 See also chapter XXX-TODO that describes how kbuild supports
1259 -----------------------------------------
1263 corresponding arch-specific section for modules; the module-building
1264 machinery is all architecture-independent.
1266 core-y, libs-y, drivers-y
1267 $(libs-y) lists directories where a lib.a archive can be located.
1269 The rest list directories where a built-in.a object file can be
1272 Then the rest follows in this order:
1274 $(core-y), $(libs-y), $(drivers-y)
1277 and arch/$(SRCARCH)/Makefile only adds architecture-specific
1283 core-y += arch/sparc/
1285 libs-y += arch/sparc/prom/
1286 libs-y += arch/sparc/lib/
1288 drivers-$(CONFIG_PM) += arch/sparc/power/
1290 Architecture-specific boot images
1291 ---------------------------------
1294 it, wrap it in bootstrapping code, and copy the resulting files
1298 It is common to locate any additional processing in a boot/
1302 target specified in boot/. Therefore arch/$(SRCARCH)/Makefile shall
1303 call make manually to build a target in boot/.
1305 The recommended approach is to include shortcuts in
1317 make in a subdirectory.
1319 There are no rules for naming architecture-specific targets,
1327 echo '* bzImage - Compressed kernel image (arch/x86/boot/bzImage)'
1331 will be built. In the top level Makefile the first goal present
1335 In ``make help``, the default goal is highlighted with a ``*``.
1345 When ``make`` is executed without arguments, bzImage will be built.
1348 -----------------------------------------
1359 LDFLAGS_bootsect := -Ttext 0x0 -s --oformat binary
1360 LDFLAGS_setup := -Ttext 0x0 -s --oformat binary -e begtext
1366 In this example, there are two possible targets, requiring different
1368 LDFLAGS_$@ syntax - one for each potential target.
1381 resulting in the target file being recompiled for no
1385 Copy binary. Uses OBJCOPYFLAGS usually specified in
1396 $(obj)/vmlinux.bin.gz: $(vmlinux.bin.all-y) FORCE
1402 in an init section in the image. Platform code *must* copy the
1403 blob to non-init memory prior to calling unflatten_device_tree().
1405 To use this command, simply add ``*.dtb`` into obj-y or targets, or make
1413 targets += $(dtb-y)
1414 DTC_FLAGS ?= -p 1024
1417 ----------------------------
1419 When the vmlinux image is built, the linker script
1423 located in the same directory.
1425 kbuild knows .lds files and includes a rule ``*lds.S`` -> ``*lds``.
1430 extra-y := vmlinux.lds
1432 The assignment to extra-y is used to tell kbuild to build the
1440 KBUILD_CPPFLAGS : Set in top-level Makefile
1441 cppflags-y : May be set in the kbuild makefile
1442 CPPFLAGS_$(@F) : Target-specific flags.
1443 Note that the full filename is used in this
1446 The kbuild infrastructure for ``*lds`` files is used in several
1447 architecture-specific files.
1450 --------------------
1452 The directory include/asm-generic contains the header files
1456 to list the file in the Kbuild file.
1458 See `generic-y`_ for further info on syntax etc.
1460 Post-link pass
1461 --------------
1464 will be invoked for post-link objects (vmlinux and modules.ko)
1465 for architectures to run post-link passes on. Must also handle
1471 .tmp_vmlinux? targets to be called from link-vmlinux.sh.
1480 Many headers can be exported as-is but other headers require a
1481 minimal pre-processing before they are ready for user-space.
1483 The pre-processing does:
1485 - drop kernel-specific annotations
1486 - drop include of compiler.h
1487 - drop all sections that are kernel internal (guarded by ``ifdef __KERNEL__``)
1494 arch/<arch>/include/asm/ to list asm files coming from asm-generic.
1498 no-export-headers
1499 -----------------
1501 no-export-headers is essentially used by include/uapi/linux/Kbuild to
1505 generic-y
1506 ---------
1509 include/asm-generic then this is listed in the file
1515 generic-y += termios.h
1516 generic-y += rtc.h
1519 file is generated in the directory::
1525 of the set of exported headers in the directory::
1529 The generated wrapper will in both cases look like the following:
1533 #include <asm-generic/termios.h>
1535 generated-y
1536 -----------
1538 If an architecture generates other header files alongside generic-y
1539 wrappers, generated-y specifies them.
1541 This prevents them being treated as stale asm-generic wrappers and
1547 generated-y += syscalls_32.h
1549 mandatory-y
1550 -----------
1552 mandatory-y is essentially used by include/(uapi/)asm-generic/Kbuild
1555 This works like optional generic-y. If a mandatory header is missing
1556 in arch/$(SRCARCH)/include/(uapi/)/asm, Kbuild will automatically
1557 generate a wrapper of the asm-generic one.
1570 three-part version number, such as "2", "4", and "0". These three
1573 $(EXTRAVERSION) defines an even tinier sublevel for pre-patches
1574 or additional patches. It is usually some non-numeric string
1575 such as "-pre4", and is often blank.
1578 $(KERNELRELEASE) is a single string such as "2.4.0-pre4", suitable
1579 for constructing installation directory names or showing in
1594 This variable specifies the directory in arch/ to build.
1598 both 32-bit and 64-bit.
1600 For example, you can pass in ARCH=i386, ARCH=x86_64, or ARCH=x86.
1607 Use this for architecture-specific install targets.
1611 installation. This variable is not defined in the Makefile but
1612 may be passed in by the user if desired.
1622 default option --strip-debug will be used. Otherwise, the
1633 GNU Make supports elementary list-processing functions. The kernel
1638 immediate evaluation of the right-hand side and stores an actual string
1639 into the left-hand side. ``=`` is like a formula definition; it stores the
1640 right-hand side in an unevaluated form and then evaluates this form each
1641 time the left-hand side is used.
1649 - Original version made by Michael Elizabeth Chastain, <mailto:mec@shout.net>
1650 - Updates by Kai Germaschewski <kai@tp1.ruhr-uni-bochum.de>
1651 - Updates by Sam Ravnborg <sam@ravnborg.org>
1652 - Language QA by Jan Engelhardt <jengelh@gmx.de>
1657 - Describe how kbuild supports shipped files with _shipped.
1658 - Generating offset header files.
1659 - Add more variables to chapters 7 or 9?