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 $(src)/decompress_$(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
430 referring to files located in the src tree.
436 prerequisites not only in the object tree but also in the source tree).
442 $(CPP) -DCHIP=810 - < $< | ... $(src)/script_asm.pl
467 echoing information to user in a rule is often a good practice
468 but when execution ``make -s`` one does not expect to see any output
471 text following $(kecho) to stdout except if ``make -s`` is used.
485 quiet_cmd_<command> - what shall be echoed
486 cmd_<command> - the command to execute
504 ------------------------
512 Kbuild achieves this by a kind of meta-programming.
514 if_changed is the macro used for this purpose, in the following form::
522 Any target that utilizes if_changed must be listed in $(targets),
524 always be built.
526 If the target is already listed in the recognized syntax such as
527 obj-y/m, lib-y/m, extra-y/m, always-y/m, hostprogs, userprogs, Kbuild
532 used in conjunction with custom rules as defined in `Custom Rules`_.
544 It stores the executed command in a corresponding .cmd
545 file and multiple calls would result in overwrites and
550 -----------------------
552 The kernel may be built with several different versions of
558 as-option
559 as-option is used to check if $(CC) -- when used to compile
560 assembler (``*.S``) files -- supports the given option. An optional
566 cflags-y += $(call as-option,-Wa$(comma)-isa=$(isa-y),)
568 In the above example, cflags-y will be assigned the option
569 -Wa$(comma)-isa=$(isa-y) if it is supported by $(CC).
573 as-instr
574 as-instr checks if the assembler reports a specific instruction
576 C escapes are supported in the test instruction
577 Note: as-instr-option uses KBUILD_AFLAGS for assembler options
579 cc-option
580 cc-option is used to check if $(CC) supports a given option, and if
586 cflags-y += $(call cc-option,-march=pentium-mmx,-march=i586)
588 In the above example, cflags-y will be assigned the option
589 -march=pentium-mmx if supported by $(CC), otherwise -march=i586.
590 The second argument to cc-option is optional, and if omitted,
591 cflags-y will be assigned no value if first option is not supported.
592 Note: cc-option uses KBUILD_CFLAGS for $(CC) options
594 cc-option-yn
595 cc-option-yn is used to check if $(CC) supports a given option
601 biarch := $(call cc-option-yn, -m32)
602 aflags-$(biarch) += -a32
603 cflags-$(biarch) += -m32
605 In the above example, $(biarch) is set to y if $(CC) supports the -m32
606 option. When $(biarch) equals "y", the expanded variables $(aflags-y)
607 and $(cflags-y) will be assigned the values -a32 and -m32,
610 Note: cc-option-yn uses KBUILD_CFLAGS for $(CC) options
612 cc-disable-warning
613 cc-disable-warning checks if $(CC) supports a given warning and returns
615 because gcc 4.4 and later accept any unknown -Wno-* option and only
616 warn about it if there is another warning in the source file.
620 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
622 In the above example, -Wno-unused-but-set-variable will be added to
625 gcc-min-version
626 gcc-min-version tests if the value of $(CONFIG_GCC_VERSION) is greater than
631 cflags-$(call gcc-min-version, 70100) := -foo
633 In this example, cflags-y will be assigned the value -foo if $(CC) is gcc and
636 clang-min-version
637 clang-min-version tests if the value of $(CONFIG_CLANG_VERSION) is greater
642 cflags-$(call clang-min-version, 110000) := -foo
644 In this example, cflags-y will be assigned the value -foo if $(CC) is clang
647 cc-cross-prefix
648 cc-cross-prefix is used to check if there exists a $(CC) in path with
650 prefix$(CC) in the PATH is returned - and if no prefix$(CC) is found
653 Additional prefixes are separated by a single space in the
654 call of cc-cross-prefix.
657 to set CROSS_COMPILE to well-known values but may have several
669 CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu-)
674 -----------------------
676 ld-option
677 ld-option is used to check if $(LD) supports the supplied option.
678 ld-option takes two options as arguments.
686 LDFLAGS_vmlinux += $(call ld-option, -X)
689 -----------------
714 Two steps are required in order to use a host executable.
720 This can be done in two ways. Either add the dependency in a rule,
721 or utilise the variable ``always-y``.
722 Both possibilities are described in the following.
725 -------------------
727 In some cases there is a need to compile and run a program on the
731 built on the build host.
737 Kbuild assumes in the above example that bin2hex is made from a single
738 c-source file named bin2hex.c located in the same directory as
742 -----------------------
747 $(<executable>-objs) lists all objects used to link the final
754 lxdialog-objs := checklist.o lxdialog.o
757 files. In the above example, checklist.c is compiled to checklist.o
761 Note: The syntax <executable>-y is not permitted for host-programs.
764 ---------------------------
766 kbuild offers support for host programs written in C++. This was
774 qconf-cxxobjs := qconf.o
776 In the example above the executable is composed of the C++ file
777 qconf.cc - identified by $(qconf-cxxobjs).
786 qconf-cxxobjs := qconf.o
787 qconf-objs := check.o
790 ----------------------------
792 Kbuild offers support for host programs written in Rust. However,
794 it may only be used in scenarios where Rust is required to be
800 target-rust := y
803 located in the same directory as the ``Makefile``. The crate may
807 ----------------------------------------------
811 the options specified in $(KBUILD_HOSTCFLAGS).
814 in that Makefile, use the variable HOST_EXTRACFLAGS.
819 HOST_EXTRACFLAGS += -I/usr/include/ncurses
827 HOSTCFLAGS_piggyback.o := -DKERNELBASE=$(KERNELBASE)
834 HOSTLDLIBS_qconf := -L$(QTDIR)/lib
837 ``-L$(QTDIR)/lib``.
839 When host programs are actually built
840 -------------------------------------
842 Kbuild will only build host-programs when they are referenced
845 This is possible in two ways:
847 (1) List the prerequisite explicitly in a custom rule.
852 hostprogs := gen-devlist
853 $(obj)/devlist.h: $(src)/pci.ids $(obj)/gen-devlist
854 ( cd $(obj); ./gen-devlist ) < $<
856 The target $(obj)/devlist.h will not be built before
857 $(obj)/gen-devlist is updated. Note that references to
858 the host programs in custom rules must be prefixed with $(obj).
860 (2) Use always-y
863 shall be built when a makefile is entered, the always-y
870 always-y := $(hostprogs)
874 hostprogs-always-y := lxdialog
876 This will tell kbuild to build lxdialog even if not referenced in
890 ------------------------
892 The following line tells kbuild that the program bpf-direct shall be
893 built for the target architecture.
897 userprogs := bpf-direct
899 Kbuild assumes in the above example that bpf-direct is made from a
900 single C source file named bpf-direct.c located in the same directory
904 ----------------------------
909 $(<executable>-objs) lists all objects used to link the final
915 userprogs := bpf-fancy
916 bpf-fancy-objs := bpf-fancy.o bpf-helper.o
919 files. In the above example, bpf-fancy.c is compiled to bpf-fancy.o
920 and bpf-helper.c is compiled to bpf-helper.o.
922 Finally, the two .o files are linked to the executable, bpf-fancy.
923 Note: The syntax <executable>-y is not permitted for userspace programs.
926 ---------------------------------------------------
930 the options specified in $(KBUILD_USERCFLAGS).
933 in that Makefile, use the variable userccflags.
938 userccflags += -I usr/include
945 bpf-helper-userccflags += -I user/include
952 bpfilter_umh-userldflags += -static
955 ``<executable>-userldlibs``. The ``userldlibs`` syntax specifies libraries
956 linked to all userspace programs created in the current Makefile.
958 When linking bpfilter_umh, it will be passed the extra option -static.
962 When userspace programs are actually built
963 ------------------------------------------
976 $(obj)/bpfilter_umh is built before $(obj)/bpfilter_umh_blob.o
978 (2) Use always-y
983 always-y := $(userprogs)
987 userprogs-always-y := binderfs_example
995 ``make clean`` deletes most generated files in the obj tree where the kernel
997 Kbuild knows targets listed in $(hostprogs), $(always-y), $(always-m),
998 $(always-), $(extra-y), $(extra-) and $(targets). They are all deleted
1003 Additional files or directories can be specified in kbuild makefiles by use of
1004 $(clean-files).
1009 clean-files := crc32table.h
1012 Kbuild will assume files to be in the same relative directory as the
1016 $(no-clean-files) variable.
1018 Usually kbuild descends down in subdirectories due to ``obj-* := dir/``,
1019 but in the architecture makefiles where the kbuild infrastructure
1025 subdir- := compressed
1027 The above assignment instructs kbuild to descend down in the
1030 Note 1: arch/$(SRCARCH)/Makefile cannot use ``subdir-``, because that file is
1031 included in the top level makefile. Instead, arch/$(SRCARCH)/Kbuild can use
1032 ``subdir-``.
1034 Note 2: All directories listed in core-y, libs-y, drivers-y and net-y will
1041 before starting to descend down in the individual directories.
1054 2) Store kernel version in include/linux/version.h
1058 - Additional prerequisites are specified in arch/$(SRCARCH)/Makefile
1060 4) Recursively descend down in all directories listed in
1061 init-* core* drivers-* net-* libs-* and build all targets.
1063 - The values of the above variables are expanded in arch/$(SRCARCH)/Makefile.
1067 The very first objects linked are listed in scripts/head-object-list.txt.
1069 6) Finally, the architecture-specific part does any required post processing
1072 - This includes building boot records
1073 - Preparing initrd images and the like
1076 ----------------------------------------------------
1087 KBUILD_LDFLAGS := -m elf_s390
1089 Note: ldflags-y can be used to further customise
1090 the flags used. See `Non-builtin vmlinux targets - extra-y`_.
1103 LDFLAGS_vmlinux := -e stext
1109 the flags specified in OBJCOPYFLAGS will be used.
1117 OBJCOPYFLAGS := -O binary
1123 In this example, the binary $(obj)/image is a binary version of
1129 Default value - see top level Makefile.
1136 KBUILD_AFLAGS += -m64 -mcpu=ultrasparc
1141 Default value - see top level Makefile.
1150 cflags-$(CONFIG_X86_32) := -march=i386
1151 cflags-$(CONFIG_X86_64) := -mcmodel=small
1152 KBUILD_CFLAGS += $(cflags-y)
1160 cflags-$(CONFIG_MPENTIUMII) += $(call cc-option,\
1161 -march=pentium2,-march=i686)
1163 # Disable unit-at-a-time mode ...
1164 KBUILD_CFLAGS += $(call cc-option,-fno-unit-at-a-time)
1174 Default value - see top level Makefile.
1180 Note that target specification file generation (for ``--target``)
1181 is handled in ``scripts/generate_rust_target.rs``.
1184 Assembler options specific for built-in
1192 $(KBUILD_AFLAGS_MODULE) is used to add arch-specific options that
1198 $(CC) options specific for built-in
1206 $(KBUILD_CFLAGS_MODULE) is used to add arch-specific options that
1212 $(RUSTC) options specific for built-in
1220 $(KBUILD_RUSTFLAGS_MODULE) is used to add arch-specific options that
1228 $(KBUILD_LDFLAGS_MODULE) is used to add arch-specific options
1234 The linker script with full path. Assigned by the top-level Makefile.
1237 All object files for vmlinux. They are linked to vmlinux in the same
1238 order as listed in KBUILD_VMLINUX_OBJS.
1240 The objects listed in scripts/head-object-list.txt are exceptions;
1249 --------------------------------
1258 --------------------------------
1261 built before starting to descend down in the subdirectories.
1270 In this example, the file target maketools will be processed
1271 before descending down in the subdirectories.
1273 See also chapter XXX-TODO that describes how kbuild supports
1277 -----------------------------------------
1281 corresponding arch-specific section for modules; the module-building
1282 machinery is all architecture-independent.
1284 core-y, libs-y, drivers-y
1285 $(libs-y) lists directories where a lib.a archive can be located.
1287 The rest list directories where a built-in.a object file can be
1290 Then the rest follows in this order:
1292 $(core-y), $(libs-y), $(drivers-y)
1295 and arch/$(SRCARCH)/Makefile only adds architecture-specific
1301 core-y += arch/sparc/
1303 libs-y += arch/sparc/prom/
1304 libs-y += arch/sparc/lib/
1306 drivers-$(CONFIG_PM) += arch/sparc/power/
1308 Architecture-specific boot images
1309 ---------------------------------
1312 it, wrap it in bootstrapping code, and copy the resulting files
1316 It is common to locate any additional processing in a boot/
1320 target specified in boot/. Therefore arch/$(SRCARCH)/Makefile shall
1321 call make manually to build a target in boot/.
1323 The recommended approach is to include shortcuts in
1335 make in a subdirectory.
1337 There are no rules for naming architecture-specific targets,
1345 echo '* bzImage - Compressed kernel image (arch/x86/boot/bzImage)'
1349 will be built. In the top level Makefile the first goal present
1353 In ``make help``, the default goal is highlighted with a ``*``.
1363 When ``make`` is executed without arguments, bzImage will be built.
1366 -----------------------------------------
1377 LDFLAGS_bootsect := -Ttext 0x0 -s --oformat binary
1378 LDFLAGS_setup := -Ttext 0x0 -s --oformat binary -e begtext
1384 In this example, there are two possible targets, requiring different
1386 LDFLAGS_$@ syntax - one for each potential target.
1399 resulting in the target file being recompiled for no
1403 Copy binary. Uses OBJCOPYFLAGS usually specified in
1414 $(obj)/vmlinux.bin.gz: $(vmlinux.bin.all-y) FORCE
1420 in an init section in the image. Platform code *must* copy the
1421 blob to non-init memory prior to calling unflatten_device_tree().
1423 To use this command, simply add ``*.dtb`` into obj-y or targets, or make
1431 targets += $(dtb-y)
1432 DTC_FLAGS ?= -p 1024
1435 ----------------------------
1437 When the vmlinux image is built, the linker script
1441 located in the same directory.
1443 kbuild knows .lds files and includes a rule ``*lds.S`` -> ``*lds``.
1448 extra-y := vmlinux.lds
1450 The assignment to extra-y is used to tell kbuild to build the
1458 KBUILD_CPPFLAGS : Set in top-level Makefile
1459 cppflags-y : May be set in the kbuild makefile
1460 CPPFLAGS_$(@F) : Target-specific flags.
1461 Note that the full filename is used in this
1464 The kbuild infrastructure for ``*lds`` files is used in several
1465 architecture-specific files.
1468 --------------------
1470 The directory include/asm-generic contains the header files
1474 to list the file in the Kbuild file.
1476 See `generic-y`_ for further info on syntax etc.
1478 Post-link pass
1479 --------------
1482 will be invoked for post-link objects (vmlinux and modules.ko)
1483 for architectures to run post-link passes on. Must also handle
1489 .tmp_vmlinux? targets to be called from link-vmlinux.sh.
1498 Many headers can be exported as-is but other headers require a
1499 minimal pre-processing before they are ready for user-space.
1501 The pre-processing does:
1503 - drop kernel-specific annotations
1504 - drop include of compiler.h
1505 - drop all sections that are kernel internal (guarded by ``ifdef __KERNEL__``)
1512 arch/<arch>/include/asm/ to list asm files coming from asm-generic.
1516 no-export-headers
1517 -----------------
1519 no-export-headers is essentially used by include/uapi/linux/Kbuild to
1523 generic-y
1524 ---------
1527 include/asm-generic then this is listed in the file
1533 generic-y += termios.h
1534 generic-y += rtc.h
1537 file is generated in the directory::
1543 of the set of exported headers in the directory::
1547 The generated wrapper will in both cases look like the following:
1551 #include <asm-generic/termios.h>
1553 generated-y
1554 -----------
1556 If an architecture generates other header files alongside generic-y
1557 wrappers, generated-y specifies them.
1559 This prevents them being treated as stale asm-generic wrappers and
1565 generated-y += syscalls_32.h
1567 mandatory-y
1568 -----------
1570 mandatory-y is essentially used by include/(uapi/)asm-generic/Kbuild
1573 This works like optional generic-y. If a mandatory header is missing
1574 in arch/$(SRCARCH)/include/(uapi/)/asm, Kbuild will automatically
1575 generate a wrapper of the asm-generic one.
1588 three-part version number, such as "2", "4", and "0". These three
1591 $(EXTRAVERSION) defines an even tinier sublevel for pre-patches
1592 or additional patches. It is usually some non-numeric string
1593 such as "-pre4", and is often blank.
1596 $(KERNELRELEASE) is a single string such as "2.4.0-pre4", suitable
1597 for constructing installation directory names or showing in
1612 This variable specifies the directory in arch/ to build.
1616 both 32-bit and 64-bit.
1618 For example, you can pass in ARCH=i386, ARCH=x86_64, or ARCH=x86.
1625 Use this for architecture-specific install targets.
1629 installation. This variable is not defined in the Makefile but
1630 may be passed in by the user if desired.
1640 default option --strip-debug will be used. Otherwise, the
1647 INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed
1658 GNU Make supports elementary list-processing functions. The kernel
1663 immediate evaluation of the right-hand side and stores an actual string
1664 into the left-hand side. ``=`` is like a formula definition; it stores the
1665 right-hand side in an unevaluated form and then evaluates this form each
1666 time the left-hand side is used.
1674 - Original version made by Michael Elizabeth Chastain, <mailto:[email protected]>
1675 - Updates by Kai Germaschewski <[email protected]-uni-bochum.de>
1676 - Updates by Sam Ravnborg <[email protected]>
1677 - Language QA by Jan Engelhardt <[email protected]>
1682 - Generating offset header files.
1683 - Add more variables to chapters 7 or 9?