1 File.........: overview.txt
2 Content......: Overview of how crosstool-NG works.
3 Copyrigth....: (C) 2007 Yann E. MORIN <yann.morin.1998@anciens.enib.fr>
4 License......: Creative Commons Attribution Share Alike (CC-by-sa), v2.5
14 Installing crosstool-NG
17 Preparing for packaging
20 Configuring crosstool-NG
21 Interesting config options
22 Re-building an existing toolchain
24 Stopping and restarting a build
25 Testing all toolchains at once
26 Overriding the number of // jobs
33 Adding a new version of a component
41 crosstool-NG aims at building toolchains. Toolchains are an essential component
42 in a software development project. It will compile, assemble and link the code
43 that is being developed. Some pieces of the toolchain will eventually end up
44 in the resulting binary/ies: static libraries are but an example.
46 So, a toolchain is a very sensitive piece of software, as any bug in one of the
47 components, or a poorly configured component, can lead to execution problems,
48 ranging from poor performance, to applications ending unexpectedly, to
49 mis-behaving software (which more than often is hard to detect), to hardware
50 damage, or even to human risks (which is more than regrettable).
52 Toolchains are made of different piece of software, each being quite complex
53 and requiring specially crafted options to build and work seamlessly. This
54 is usually not that easy, even in the not-so-trivial case of native toolchains.
55 The work reaches a higher degree of complexity when it comes to cross-
56 compilation, where it can become quite a nightmare...
58 Some cross-toolchains exist on the internet, and can be used for general
59 development, but they have a number of limitations:
60 - they can be general purpose, in that they are configured for the majority:
61 no optimisation for your specific target,
62 - they can be prepared for a specific target and thus are not easy to use,
63 nor optimised for, or even supporting your target,
64 - they often are using aging components (compiler, C library, etc...) not
65 supporting special features of your shiny new processor;
66 On the other side, these toolchain offer some advantages:
67 - they are ready to use and quite easy to install and setup,
68 - they are proven if used by a wide community.
70 But once you want to get all the juice out of your specific hardware, you will
71 want to build your own toolchain. This is where crosstool-NG comes into play.
73 There are also a number of tools that build toolchains for specific needs,
74 which are not really scalable. Examples are:
75 - buildroot (buildroot.uclibc.org) whose main purpose is to build root file
76 systems, hence the name. But once you have your toolchain with buildroot,
77 part of it is installed in the root-to-be, so if you want to build a whole
78 new root, you either have to save the existing one as a template and
79 restore it later, or restart again from scratch. This is not convenient,
80 - ptxdist (www.pengutronix.de/software/ptxdist), whose purpose is very
82 - other projects (openembedded.org for example), which are again used to
83 build root file systems.
85 crosstool-NG is really targeted at building toolchains, and only toolchains.
86 It is then up to you to use it the way you want.
93 crosstool was first 'conceived' by Dan Kegel, who offered it to the community
94 as a set of scripts, a repository of patches, and some pre-configured, general
95 purpose setup files to be used to configure crosstool. This is available at
96 http://www.kegel.com/crosstool, and the subversion repository is hosted on
97 google at http://code.google.com/p/crosstool/.
99 I once managed to add support for uClibc-based toolchains, but it did not make
100 into mainline, mostly because I didn't have time to port the patch forward to
101 the new versions, due in part to the big effort it was taking.
103 So I decided to clean up crosstool in the state it was, re-order the things
104 in place, add appropriate support for what I needed, that is uClibc support
105 and a menu-driven configuration, named the new implementation crosstool-NG,
106 (standing for crosstool Next Generation, as many other comunity projects do,
107 and as a wink at the TV series "Star Trek: The Next Generation" ;-) ) and
108 made it available to the community, in case it was of interest to any one.
110 ___________________________
112 Installing crosstool-NG /
113 ________________________/
115 There are two ways you can use crosstool-NG:
116 - build and install it, then get rid of the sources like you'd do for most
118 - or only build it and run from the source directory.
120 The former should be used if you got crosstool-NG from a packaged tarball, see
121 "Install method", below, while the latter is most useful for developpers that
122 checked the code out from SVN, and want to submit patches, see "The Hacker's
128 If you go for the install, then you just follow the classical, but yet easy
130 ./configure --prefix=/some/place
133 export PATH="${PATH}:/some/place/bin"
135 You can then get rid of crosstool-NG source. Next create a directory to serve
136 as a working place, cd in there and run:
139 See below for complete usage.
144 If you go the hacker's way, then the usage is a bit different, although very
150 Now, *do not* remove crosstool-NG sources. They are needed to run crosstool-NG!
151 Stay in the directory holding the sources, and run:
154 See below for complete usage.
156 Now, provided you checked-out the code, you can send me your interesting changes
160 and mailing me the result! :-P
162 Preparing for packaging |
163 ------------------------+
165 If you plan on packaging crosstool-NG, you surely don't want to install it
166 in your root file system. The install procedure of crosstool-NG honors the
169 ./configure --prefix=/usr
171 make DESTDIR=/packaging/place install
176 crosstool-NG comes with a shell script fragment that defines bash-compatible
177 completion. That shell fragment is currently not installed automatically, but
180 To install the shell script fragment, you have two options:
181 - install system-wide, most probably by copying ct-ng.comp into
182 /etc/bash_completion.d/
183 - install for a single user, by copying ct-ng.comp into ${HOME}/ and
184 sourcing this file from your ${HOME}/.bashrc
189 Some people contibuted code that couldn't get merged for various reasons. This
190 code is available as patches in the contrib/ sub-directory. These patches are
191 to be applied to the source of crosstool-NG, prior to installing.
193 An easy way to use contributed code is to pass the --with-contrib= option to
194 ./configure. The possible values depend upon which contributions are packaged
195 with your version, but you can get with it with passing one of those two
198 will list all available contributions
201 will select all avalaible contributions
203 There is no guarantee that a particuliar contribution applies to the current
204 version of crosstool-ng, or that it will work at all. Use contributions at
207 ____________________________
209 Configuring crosstool-NG /
210 _________________________/
212 crosstool-NG is configured with a configurator presenting a menu-stuctured set
213 of options. These options let you specify the way you want your toolchain
214 built, where you want it installed, what architecture and specific processor it
215 will support, the version of the components you want to use, etc... The
216 value for those options are then stored in a configuration file.
218 The configurator works the same way you configure your Linux kernel. It is
219 assumed you now how to handle this.
221 To enter the menu, type:
224 Almost every config item has a help entry. Read them carefully.
226 String and number options can refer to environment variables. In such a case,
227 you must use the shell syntax: ${VAR}. You shall neither single- nor double-
228 quote the string/number options.
230 There are three environment variables that are computed by crosstool-NG, and
234 It represents the target tuple you are building for. You can use it for
235 example in the installation/prefix directory, such as:
236 /opt/x-tools/${CT_TARGET}
239 The top directory where crosstool-NG is running. You shouldn't need it in
240 most cases. There is one case where you may need it: if you have local
241 patches and you store them in your running directory, you can refer to them
242 by using CT_TOP_DIR, such as:
243 ${CT_TOP_DIR}/patches.myproject
246 The version of crosstool-NG you are using. Not much use for you, but it's
247 there if you need it.
249 Interesting config options |
250 ---------------------------+
252 CT_LOCAL_TARBALLS_DIR:
253 If you already have some tarballs in a direcotry, enter it here. That will
254 speed up the retrieving phase, where crosstool-NG would otherwise download
258 This is where the toolchain will be installed in (and for now, where it
259 will run from). Common use is to add the target tuple in the directory
260 path, such as (see above):
261 /opt/x-tools/${CT_TARGET}
264 An identifier for your toolchain, will take place in the vendor part of the
265 target tuple. It shall *not* contain spaces or dashes. Usually, keep it
266 to a one-word string, or use underscores to separate words if you need.
267 Avoid dots, commas, and special characters.
270 An alias for the toolchian. It will be used as a prefix to the toolchain
271 tools. For example, you will have ${CT_TARGET_ALIAS}-gcc
273 Also, if you think you don't see enough versions, you can try to enable one of
277 Show obsolete versions or tools. Most of the time, you don't want to base
278 your toolchain on too old a version (of gcc, for example). But at times, it
279 can come handy to use such an old version for regression tests. Those old
280 versions are hidden behind CT_OBSOLETE. Those versions (or features) are so
281 marked because maintaining support for those in crosstool-NG would be too
282 costly, time-wise, and time is dear.
285 Show experimental versions or tools. Again, you might not want to base your
286 toolchain on too recent tools (eg. gcc) for production. But if you need a
287 feature present only in a recent version, or a new tool, you can find them
288 hidden behind CT_EXPERIMENTAL. Those versions (or features) did not (yet)
289 receive thorough testing in crosstool-NG, and/or are not mature enough to
292 Re-building an existing toolchain |
293 ----------------------------------+
295 If you have an existing toolchain, you can re-use the options used to build it
296 to create a new toolchain. That needs a very little bit of effort on your side
297 but is quite easy. The options to build a toolchain are saved with the
298 toolchain, and you can retrieve this configuration by running:
301 This will dump the configuration to stdout, so to rebuild a toolchain with this
302 configuration, the following is all you need to do:
303 ${CT_TARGET}-config >.config
306 Then, you can review and change the configuration by running:
309 ________________________
311 Running crosstool-NG /
312 _____________________/
314 To build the toolchain, simply type:
317 This will use the above configuration to retrieve, extract and patch the
318 components, build, install and eventually test your newly built toolchain.
320 You are then free to add the toolchain /bin directory in your PATH to use
323 In any case, you can get some terse help. Just type:
328 Stopping and restarting a build |
329 --------------------------------+
331 If you want to stop the build after a step you are debugging, you can pass the
332 variable STOP to make:
335 Conversely, if you want to restart a build at a specific step you are
336 debugging, you can pass the RESTART variable to make:
337 ct-ng RESTART=some_step
339 Alternatively, you can call make with the name of a step to just do that step:
342 ct-ng RESTART=libc_headers STOP=libc_headers
344 The shortcuts +step_name and step_name+ allow to respectively stop or restart
346 ct-ng +libc_headers and: ct-ng libc_headers+
348 ct-ng STOP=libc_headers and: ct-ng RESTART=libc_headers
350 To obtain the list of acceptable steps, please call:
353 Note that in order to restart a build, you'll have to say 'Y' to the config
354 option CT_DEBUG_CT_SAVE_STEPS, and that the previous build effectively went
357 Building all toolchains at once |
358 --------------------------------+
360 You can build all samples; simply call:
363 Overriding the number of // jobs |
364 ---------------------------------+
366 If you want to override the number of jobs to run in // (the -j option to
367 make), you can either re-enter the menuconfig, or simply add it on the command
371 which tells crosstool-NG to override the number of // jobs to 4.
373 You can see the actions that support overriding the number of // jobs in
374 the help menu. Those are the ones with [.#] after them (eg. build[.#] or
375 build-all[.#], and so on...).
380 The crosstool-NG script 'ct-ng' is a Makefile-script. It does *not* execute
381 in parallel (there is not much to gain). When speaking of // jobs, we are
382 refering to the number of // jobs when making the *components*. That is, we
383 speak of the number of // jobs used to build gcc, glibc, and so on...
386 _______________________
388 Using the toolchain /
389 ____________________/
391 Using the toolchain is as simple as adding the toolchain's bin directory in
393 export PATH="${PATH}:/your/toolchain/path/bin"
395 and then using the target tuple to tell the build systems to use your
397 ./configure --target=your-target-tuple
399 make CC=your-target-tuple-gcc
401 make CROSS_COMPILE=your-target-tuple-
404 It is strongly advised not to use the toolchain sys-root directory as an
405 install directory for your programs/packages. If you do so, you will not be
406 able to use your toolchain for another project. It is even strongly advised
407 that your toolchain is chmod-ed to read-only once successfully build, so that
408 you don't go polluting your toolchain with your programs/packages' files.
410 Thus, when you build a program/package, install it in a separate directory,
411 eg. /your/root. This directory is the /image/ of what would be in the root file
412 system of your target, and will contain all that your programs/packages have
415 The 'populate' script |
416 ----------------------+
418 When your root directory is ready, it is still missing some important bits: the
419 toolchain's libraries. To populate your root directory with those libs, just
421 your-target-tuple-populate -s /your/root -d /your/root-populated
423 This will copy /your/root into /your/root-populated, and put the needed and only
424 the needed libraries there. Thus you don't polute /your/root with any cruft that
425 would no longer be needed should you have to remove stuff. /your/root always
426 contains only those things you install in it.
428 You can then use /your/root-populated to build up your file system image, a
429 tarball, or to NFS-mount it from your target, or whatever you need.
431 The populate script accepts the following options:
434 Use 'src_dir' as the un-populated root directory.
437 Put the populated root directory in 'dst_dir'.
440 Always add specified libraries.
443 Always add libraries listed in 'file'.
446 Remove 'dst_dir' if it previously existed; continue even if any library
447 specified with -l or -L is missing.
450 Be verbose, and tell what's going on (you can see exactly where libs are
456 See 'your-target-tuple-populate -h' for more information on the options.
463 There are four kinds of toolchains you could encounter.
465 First off, you must understand the following: when it comes to compilers there
466 are up to four machines involved:
467 1) the machine configuring the toolchain components: the config machine
468 2) the machine building the toolchain components: the build machine
469 3) the machine running the toolchain: the host machine
470 4) the machine the toolchain is generating code for: the target machine
472 We can most of the time assume that the config machine and the build machine
473 are the same. Most of the time, this will be true. The only time it isn't
474 is if you're using distributed compilation (such as distcc). Let's forget
475 this for the sake of simplicity.
477 So we're left with three machines:
482 Any toolchain will involve those three machines. You can be as pretty sure of
483 this as "2 and 2 are 4". Here is how they come into play:
485 1) build == host == target
486 This is a plain native toolchain, targetting the exact same machine as the
487 one it is built on, and running again on this exact same machine. You have
488 to build such a toolchain when you want to use an updated component, such
489 as a newer gcc for example.
490 crosstool-NG calls it "native".
492 2) build == host != target
493 This is a classic cross-toolchain, which is expected to be run on the same
494 machine it is compiled on, and generate code to run on a second machine,
496 crosstool-NG calls it "cross".
498 3) build != host == target
499 Such a toolchain is also a native toolchain, as it targets the same machine
500 as it runs on. But it is build on another machine. You want such a
501 toolchain when porting to a new architecture, or if the build machine is
502 much faster than the host machine.
503 crosstool-NG calls it "cross-native".
505 4) build != host != target
506 This one is called a canadian-toolchain (*), and is tricky. The three
507 machines in play are different. You might want such a toolchain if you
508 have a fast build machine, but the users will use it on another machine,
509 and will produce code to run on a third machine.
510 crosstool-NG calls it "canadian".
512 crosstool-NG can build all these kinds of toolchains (or is aiming at it,
515 (*) The term Canadian Cross came about because at the time that these issues
516 were all being hashed out, Canada had three national political parties.
517 http://en.wikipedia.org/wiki/Cross_compiler
524 Internally, crosstool-NG is script-based. To ease usage, the frontend is
530 The entry point to crosstool-NG is the Makefile script "ct-ng". Calling this
531 script with an action will act exactly as if the Makefile was in the current
532 working directory and make was called with the action as rule. Thus:
535 is equivalent to having the Makefile in CWD, and calling:
538 Having ct-ng as it is avoids copying the Makefile everywhere, and acts as a
541 ct-ng loads sub- Makefiles from the library directory $(CT_LIB_DIR), as set up
542 at configuration time with ./configure.
544 ct-ng also searches for config files, sub-tools, samples, scripts and patches in
545 that library directory.
547 Because of a stupid make behavior/bug I was unable to track down, implicit make
548 rules are disabled: installing with --local would triger those rules, and mconf
554 The kconfig language is a hacked version, vampirised from the Linux kernel
555 (http://www.kernel.org/), and (heavily) adapted to my needs.
557 The list of the most notable changes (at least the ones I remember) follows:
558 - the CONFIG_ prefix has been replaced with CT_
559 - a leading | in prompts is skipped, and subsequent leading spaces are not
561 - otherwise leading spaces are silently trimmed
563 The kconfig parsers (conf and mconf) are not installed pre-built, but as
564 source files. Thus you can have the directory where crosstool-NG is installed,
565 exported (via NFS or whatever) and have clients with different architectures
566 use the same crosstool-NG installation, and most notably, the same set of
569 Architecture-specific |
570 ----------------------+
572 Note: this chapter is not really well written, and might thus be a little bit
573 complex to understand. To get a better grasp of what an architecture is, the
574 reader is kindly encouraged to look at the "arch/" sub-directory, and to the
575 existing architectures to see how things are laid out.
577 An architecture is defined by:
579 - a human-readable name, in lower case letters, with numbers as appropriate.
580 The underscore is allowed; space and special characters are not.
582 - a file in "config/arch/", named after the architecture's name, and suffixed
584 Eg.: config/arch/arm.in
585 - a file in "scripts/build/arch/", named after the architecture's name, and
587 Eg.: scripts/build/arch/arm.sh
589 The architecture's ".in" file API:
590 > the config option "ARCH_%arch%" (where %arch% is to be replaced with the
591 actual architecture name).
592 That config option must have *neither* a type, *nor* a prompt! Also, it can
593 *not* depend on any other config option (EXPERIMENTAL is managed as above).
597 defines a (terse) help entry for this architecture:
601 The ARM architecture.
603 selects adequate associated config options.
604 Note: 64-bit architectures *shall* select ARCH_64
607 select ARCH_SUPPORTS_BOTH_ENDIAN
608 select ARCH_DEFAULT_LE
610 The ARM architecture.
615 The x86_64 architecture.
617 > other target-specific options, at your discretion. Note however that to
618 avoid name-clashing, such options shall be prefixed with "ARCH_%arch%",
619 where %arch% is again replaced by the actual architecture name.
620 (Note: due to historical reasons, and lack of time to clean up the code,
621 I may have left some config options that do not completely conform to
622 this, as the architecture name was written all upper case. However, the
623 prefix is unique among architectures, and does not cause harm).
625 The architecture's ".sh" file API:
626 > the function "CT_DoArchTupleValues"
629 - all variables from the ".config" file,
630 - the two variables "target_endian_eb" and "target_endian_el" which are
631 the endianness suffixes
632 + return value: 0 upon success, !0 upon failure
635 - the environment variable CT_TARGET_ARCH
637 the architecture part of the target tuple.
638 Eg.: "armeb" for big endian ARM
642 - the environment variable CT_TARGET_SYS
644 the sytem part of the target tuple.
645 Eg.: "gnu" for glibc on most architectures
646 "gnueabi" for glibc on an ARM EABI
648 - for glibc-based toolchain: "gnu"
649 - for uClibc-based toolchain: "uclibc"
652 - the environment variable CT_KERNEL_ARCH
654 the architecture name as understandable by the Linux kernel build
656 Eg.: "arm" for an ARM
657 "powerpc" for a PowerPC
663 - the environment variables to configure the cross-gcc (defaults)
664 - CT_ARCH_WITH_ARCH : the gcc ./configure switch to select architecture level ( "--with-arch=${CT_ARCH_ARCH}" )
665 - CT_ARCH_WITH_ABI : the gcc ./configure switch to select ABI level ( "--with-abi=${CT_ARCH_ABI}" )
666 - CT_ARCH_WITH_CPU : the gcc ./configure switch to select CPU instruction set ( "--with-cpu=${CT_ARCH_CPU}" )
667 - CT_ARCH_WITH_TUNE : the gcc ./configure switch to select scheduling ( "--with-tune=${CT_ARCH_TUNE}" )
668 - CT_ARCH_WITH_FPU : the gcc ./configure switch to select FPU type ( "--with-fpu=${CT_ARCH_FPU}" )
669 - CT_ARCH_WITH_FLOAT : the gcc ./configure switch to select floating point arithmetics ( "--with-float=soft" or /empty/ )
672 - the environment variables to pass to the cross-gcc to build target binaries (defaults)
673 - CT_ARCH_ARCH_CFLAG : the gcc switch to select architecture level ( "-march=${CT_ARCH_ARCH}" )
674 - CT_ARCH_ABI_CFLAG : the gcc switch to select ABI level ( "-mabi=${CT_ARCH_ABI}" )
675 - CT_ARCH_CPU_CFLAG : the gcc switch to select CPU instruction set ( "-mcpu=${CT_ARCH_CPU}" )
676 - CT_ARCH_TUNE_CFLAG : the gcc switch to select scheduling ( "-mtune=${CT_ARCH_TUNE}" )
677 - CT_ARCH_FPU_CFLAG : the gcc switch to select FPU type ( "-mfpu=${CT_ARCH_FPU}" )
678 - CT_ARCH_FLOAT_CFLAG : the gcc switch to choose floating point arithmetics ( "-msoft-float" or /empty/ )
679 - CT_ARCH_ENDIAN_CFLAG : the gcc switch to choose big or little endian ( "-mbig-endian" or "-mlittle-endian" )
684 - the environement variables to configure the core and final compiler, specific to this architecture:
685 - CT_ARCH_CC_CORE_EXTRA_CONFIG : additional, architecture specific core gcc ./configure flags
686 - CT_ARCH_CC_EXTRA_CONFIG : additional, architecture specific final gcc ./configure flags
691 - the architecture-specific CFLAGS and LDFLAGS:
692 - CT_ARCH_TARGET_CLFAGS
693 - CT_ARCH_TARGET_LDFLAGS
697 You can have a look at "config/arch/arm.in" and "scripts/build/arch/arm.sh" for
698 a quite complete example of what an actual architecture description looks like.
703 A kernel is defined by:
705 - a human-readable name, in lower case letters, with numbers as appropriate.
706 The underscore is allowed; space and special characters are not (although
707 they are internally replaced with underscores.
708 Eg.: linux, bare-metal
709 - a file in "config/kernel/", named after the kernel name, and suffixed with
711 Eg.: config/kernel/linux.in, config/kernel/bare-metal.in
712 - a file in "scripts/build/kernel/", named after the kernel name, and suffixed
714 Eg.: scripts/build/kernel/linux.sh, scripts/build/kernel/bare-metal.sh
716 The kernel's ".in" file must contain:
717 > an optional lines containing exactly "# EXPERIMENTAL", starting on the
718 first column, and without any following space or other character.
719 If this line is present, then this kernel is considered EXPERIMENTAL,
720 and correct dependency on EXPERIMENTAL will be set.
722 > the config option "KERNEL_%kernel_name%" (where %kernel_name% is to be
723 replaced with the actual kernel name, with all special characters and
724 spaces replaced by underscores).
725 That config option must have *neither* a type, *nor* a prompt! Also, it can
726 *not* depends on EXPERIMENTAL.
727 Eg.: KERNEL_linux, KERNEL_bare_metal
729 defines a (terse) help entry for this kernel.
731 config KERNEL_bare_metal
733 Build a compiler for use without any kernel.
735 selects adequate associated config options.
737 config KERNEL_bare_metal
740 Build a compiler for use without any kernel.
742 > other kernel specific options, at your discretion. Note however that, to
743 avoid name-clashing, such options should be prefixed with
744 "KERNEL_%kernel_name%", where %kernel_name% is again tp be replaced with
745 the actual kernel name.
746 (Note: due to historical reasons, and lack of time to clean up the code,
747 I may have left some config options that do not completely conform to
748 this, as the kernel name was written all upper case. However, the prefix
749 is unique among kernels, and does not cause harm).
751 The kernel's ".sh" file API:
752 > is a bash script fragment
754 > defines the function CT_DoKernelTupleValues
755 + see the architecture's CT_DoArchTupleValues, except for:
756 + set the environment variable CT_TARGET_KERNEL, the kernel part of the
758 + return value: ignored
760 > defines the function "do_kernel_get":
763 - all variables from the ".config" file.
764 + return value: 0 for success, !0 for failure.
765 + behavior: download the kernel's sources, and store the tarball into
766 "${CT_TARBALLS_DIR}". To this end, a functions is available, that
767 abstracts downloading tarballs:
768 - CT_DoGet <tarball_base_name> <URL1 [URL...]>
769 Eg.: CT_DoGet linux-2.6.26.5 ftp://ftp.kernel.org/pub/linux/kernel/v2.6
770 Note: retrieving sources from svn, cvs, git and the likes is not supported
771 by CT_DoGet. You'll have to do this by hand, as it is done for eglibc in
772 "scripts/build/libc/eglibc.sh"
774 > defines the function "do_kernel_extract":
777 - all variables from the ".config" file,
778 + return value: 0 for success, !0 for failure.
779 + behavior: extract the kernel's tarball into "${CT_SRC_DIR}", and apply
780 required patches. To this end, a function is available, that abstracts
782 - CT_ExtractAndPatch <tarball_base_name>
783 Eg.: CT_ExtractAndPatch linux-2.6.26.5
785 > defines the function "do_kernel_headers":
788 - all variables from the ".config" file,
789 + return value: 0 for success, !0 for failure.
790 + behavior: install the kernel headers (if any) in "${CT_SYSROOT_DIR}/usr/include"
792 > defines any kernel-specific helper functions
793 These functions, if any, must be prefixed with "do_kernel_%CT_KERNEL%_",
794 where '%CT_KERNEL%' is to be replaced with the actual kernel name, to avoid
797 You can have a look at "config/kernel/linux.in" and "scripts/build/kernel/linux.sh"
798 as an example of what a complex kernel description looks like.
800 Adding a new version of a component |
801 ------------------------------------+
803 When a new component, such as the Linux kernel, gcc or any other is released,
804 adding the new version to crosstool-NG is quite easy. There is a script that
805 will do all that for you:
806 scripts/addToolVersion.sh
808 Run it with no option to get some help.
813 To Be Written later...