README ^^^^^^
o Installation
INSTALLATION ^^^^^^^^^^^^
NuttX may be installed and built on a Linux system or on a Windows system if Cygwin is installed. Installing Cygwin on your Windows PC is simple, but time consuming. See http://www.cygwin.com/ for installation instructions. Basically you just need to download a tiny setup.exe program and it does the real, internet installation for you.
NOTE: NuttX can also be installed and built on a native Windows
system, but with some loss of tool functionality (see the
discussion "Native Windows Build" below).Some Cygwin installation tips:
Install at C:\cygwin
Install EVERYTHING: "Only the minimal base packages from the Cygwin distribution are installed by default. Clicking on categories and packages in the setup.exe package installation screen will provide you with the ability to control what is installed or updated. Clicking on the "Default" field next to the "All" category will provide you with the opportunity to install every Cygwin package. Be advised that this will download and install hundreds of megabytes to your computer."
If you use the "default" installation, you will be missing many of the Cygwin utilities that you will need to build NuttX. The build will fail in numerous places because of missing packages.
After installing Cygwin, you will get lots of links for installed tools and shells. I use the RXVT native shell. It is fast and reliable and does not require you to run the Cygwin X server (which is neither fast nor reliable). Unless otherwise noted, the rest of these instructions assume that you are at a bash command line prompt in either Linux or in Cygwin shell.
Download and unpack the NuttX tarball. If you are reading this, then you have probably already done that. After unpacking, you will end up with a directory called nuttx-version (where version is the NuttX version number). You might want to rename that directory nuttx to match the various instructions in the documentation and some scripts in the source tree.
All NuttX libraries and example code used to be in included within the NuttX source tree. As of NuttX-6.0, this application code was moved into a separate tarball, the apps tarball. If you are just beginning with NuttX, then you will want to download the versioned apps tarball along with the NuttX tarball. If you already have your own product application directory, then you may not need the apps tarball.
It is call "Semi-optional" because if you don't have some apps/ directory, NuttX will fail to build!
Download the unpack the apps tarball in the same directly where you unpacked the NuttX tarball. After you unpack the apps tarball, you will have a new directory called apps-version (where the version should exactly match the version of the NuttX tarball). Again, you might want to rename the directory to simply apps/ to match what you read in the documentation
After unpacking the apps tarball, you will have two directories side by side like this:
|
+----+----+
| |
nuttx/ apps/This is important because the NuttX build will expect to find the apps directory in that (default) location. )That default location can be changed by editing your NuttX configuration file, but that is another story).
The nuttx build directory should reside in a path that contains no spaces in any higher level directory name. For example, under Cygwin, your home directory might be formed from your first and last names like: "/home/First Last". That will cause strange errors when the make system tries to build.
[Actually, that problem is probably not to difficult to fix. Some Makefiles probably just need some paths within double quotes]
I work around spaces in the home directory name, by creating a new directory that does not contain any spaces, such as /home/nuttx. Then I install NuttX in /home/nuttx and always build from /home/nuttx/nuttx-code.
The current NuttX du jour is available in from a GIT repository. Download instructions are available here:
https://sourceforge.net/p/nuttx/git
Other C-Library Header Files.
Some toolchains are built with header files extracted from a C-library
distribution (such as newlib). These header files must *not* be used
with NuttX because NuttX provides its own, built-in C-Library. For
toolchains that do include built-in header files from a foreign C-
Library, NuttX must be compiled without using the standard header files
that are distributed with your toolchain. This prevents including
conflicting, incompatible header files (such as stdio.h).Header Files Provided by Your Toolchain.
Certain header files, such as setjmp.h, stdarg.h, and math.h, may still
be needed from your toolchain and your compiler may not, however, be able
to find these if you compile NuttX without using standard header file.
If that is the case, one solution is to copy those header file from
your toolchain into the NuttX include directory.Duplicated Header Files.
There are also a few header files that can be found in the nuttx/include
directory which are duplicated by the header files from your toolchain.
stdint.h and stdbool.h are examples. If you prefer to use the stdint.h
and stdbool.h header files from your toolchain, those could be copied
into the nuttx/include/ directory. Using most other header files from
your toolchain would probably cause errors.math.h
Even though you should not use a foreign C-Library, you may still need
to use other, external libraries with NuttX. In particular, you may
need to use the math library, libm.a. NuttX supports a generic, built-in
math library that can be enabled using CONFIG_LIBM=y. However, you may
still want to use a higher performance external math library that has
been tuned for your CPU. Sometimes such such tuned math libraries are
bundled with your toolchain.
The math libary header file, math.h, is a then special case. If you do
nothing, the standard math.h header file that is provided with your
toolchain will be used.
If you have a custom, architecture specific math.h header file, then
that header file should be placed at arch/<cpu>/include/math.h. There
is a stub math.h header file located at include/nuttx/math.h. This stub
header file can be used to "redirect" the inclusion to an architecture-
specific math.h header file. If you add an architecture specific math.h
header file then you should also define CONFIG_ARCH_MATH_H=y in your
NuttX Configuration file. If CONFIG_ARCH_MATH_H is selected, then the
top-level Makefile will copy the stub math.h header file from
include/nuttx/matn.h to include/math.h where it will become the system
math.h header file. The stub math.h header file does nothing other
than to include that archicture-specific math.h header file as the
system math.h header file.float.h
If you enable the generic, built-in math library, then that math library
will expect your toolchain to provide the standard float.h header file.
The float.h header file defines the properties of your floating point
implementation. It would always be best to use your toolchain's float.h
header file but if none is avaiable, a default float.h header file will
provided if this option is selected. However, there is no assurance that
the settings in this float.h are actually correct for your platform!stdarg.h
In most cases, the correct version of stdarg.h is the version provided
with your toolchain. However, sometimes there are issues with with
using your toolchains stdarg.h. For example, it may attempt to draw in
header files that do not exist in NuttX or perhaps the header files that
is uses are not compatible with the NuttX header files. In those cases,
you can use an architecture-specific stdarg.h header file by defining
CONFIG_ARCH_STDARG_H=y.
See the discussion above for the math.h header. This setting works
exactly the same for the stdarg.h header file.CONFIGURING NUTTX ^^^^^^^^^^^^^^^^^
"Canned" NuttX configuration files are retained in:
configs/
Where
Copy configs/
Make.defs describes the rules needed by you tool chain to compile
and link code. You may need to modify this file to match the
specific needs of your toolchain.Copy configs/
setenv.sh is an optional convenience file that I use to set
the PATH variable to the toolchain binaries. You may chose to
use setenv.sh or not. If you use it, then it may need to be
modified to include the path to your toolchain binaries.Copy configs/
The defconfig file holds the actual build configuration. This
file is included by all other make files to determine what is
included in the build and what is not. This file is also used
to generate a C configuration header at include/nuttx/config.h.Copy configs/
The appconfig file describes the applications that need to be
built in the appliction directory (APPSDIR). Not all configurations
have an appconfig file. This file is deprecated and will not be
used with new defconfig files produced with the kconfig-mconf
configuration tool.General information about configuring NuttX can be found in:
${TOPDIR}/configs/README.txt
${TOPDIR}/configs/
There is a configuration script in the tools/ directory that makes this easier. It is used as follows:
cd ${TOPDIR}/tools
./configure.sh
There is an alternative Windows batch file that can be used in the windows native enironment like:
cd ${TOPDIR}\tools
configure.bat
See tools/README.txt for more information about these scripts.
An automated tool is under development to support re-configuration of NuttX. This tool, however, is not yet quite ready for general usage.
This automated tool is based on the kconfig-frontends application available at http://ymorin.is-a-geek.org/projects/kconfig-frontends (A snapshot of this tool is also available at ../misc/tools). This application provides a tool called 'mconf' that is used by the NuttX top-level Makefile. The following make target is provided:
make menuconfigThis make target will bring up NuttX configuration menus.
WARNING: Never do 'make menuconfig' on a configuration that has not been converted to use the kconfig-frontends tools! This will damage your configuration (see http://www.nuttx.org/doku.php?id=wiki:howtos:convertconfig).
The 'menuconfig' make target depends on two things:
The Kconfig configuration data files that appear in almost all NuttX directories. These data files are the part that is still under development (patches are welcome!). The Kconfig files contain configuration information for the configuration settings relevant to the directory in which the Kconfig file resides.
NOTE: For a description of the syntax of this configuration file, see ../misc/tools/kconfig-language.txt.
The 'mconf' tool. 'mconf' is part of the kconfig-frontends package. You can download that package from the website http://ymorin.is-a-geek.org/projects/kconfig-frontends or you can use the snapshot in ../misc/tools.
Building may be as simple as 'configure; make; make install' but there may be some build complexities, especially if you are building under Cygwin. See the more detailed build instructions at ../misc/tools/README.txt
The 'make install' step will, by default, install the 'mconf' tool at /usr/local/bin/mconf. Where ever you choose to install 'mconf', make certain that your PATH variable includes a path to that installation directory.
The basic configuration order is "bottom-up":
This is pretty straight forward for creating new configurations but may be less intuitive for modifying existing configurations.
Whenever you use a configuration, you really should always do the following before you make NuttX:
make oldconfigThis will make sure that the configuration is up-to-date in the event that it has lapsed behind the current NuttX development.
WARNING: Never do 'make oldconfig' (OR 'make menuconfig') on a configuration that has not been converted to use the kconfig-frontends tools! This will damage your configuration (see http://www.nuttx.org/doku.php?id=wiki:howtos:convertconfig).
WARNING
The old legacy, manual configurations and the new kconfig-frontends configurations are not 100% compatible. Old legacy configurations can not be used with the kconfig-frontends tool: If you run 'make menuconfig' with a legacy configuration the resulting configuration will probably not be functional.
Q: How can I tell if a configuration is a new kconfig-frontends configuration or an older, manual configuration?
A: a) New kcondfig-frontends configurations will have this setting within the defconfig/.config file":
CONFIG_NUTTX_NEWCONFIG=y
b) Only old, manual configurations will have an appconfig fileQ: How can I convert a older, manual configuration into a new, kconfig-frontends toolchain.
A: 1) Look at the appconfig file: Each application path there will now have to have an enabling setting. For example, if the old appconfig file had:
CONFIGURED_APPS = examples/ostest
Then the new configuration will need:
CONFIG_EXAMPLES_OSTEST=y
The appconfig file can then be deleted because it will not
be needed after the conversion.
2) Build the cmpconfig utility at tools:
cd tools
make -f Makefile.host cmpconfig
3) Perform these steps repeatedly until you are convinced that
the configurations are the same:
a) Repeat the following until you have account for all of the differences:
cp configs/<board>/<condfiguration>/defconfig .config
make menuconfig (Just exit and save the new .config file)
tools/cmpconfig configs/<board>/<condfiguration>/defconfig .config | grep file1
The final grep will show settings in the old defconfig file that
do not appear in the new .config file (or have a different value
in the new .config file). In the new configuration, you will
probably have to enable certain groups of features. Such
hierarachical enabling options were not part of the older
configuration.
b) Then make sure these all make sense:
tools/cmpconfig configs/<board>/<condfiguration>/defconfig .config | grep file2
The final grep will show settings in the new .config file that
do not appear in the older defconfig file (or have a different value
in the new .config file). Here you should see only the new
hierarachical enabling options (such as CONFIG_SPI or CONFIG_MMCSD)
plus some other internal configuration settings (like CONFIG_ARCH_HAVE_UART0).
You will have to convince yourself that these new settings all make sense.
4) Finally, update the configuration:
cp .config configs/<board>/<condfiguration>/defconfig
rm configs/<board>/<condfiguration>/appconfig
NOTE: You should comment out the line containing the CONFIG_APPS_DIR
in the new defconfig file. Why? Because the application directory
may reside at a different location when the configuration is installed
at some later time.
# CONFIG_APPS_DIR="../apps"
5) The updated configuration can then be instantiated in the normal
fashion:
cd tools
./configure.sh <board>/<condfiguration>
(or configure.bat for the case of the Windows native build).
NOTE: If CONFIG_APPS_DIR is not defined in the defconfig file,
the configure.sh script will find and add the new, correct path to
the application directory (CONFIG_APPS_DIR) when it copies the
defconfig file to the .config file. This is the setting that was
commented out in step 4.Recent versions of NuttX support building NuttX from a native Windows console window (see "Native Windows Build" below). But kconfig-frontends is a Linux tool. There have been some successes building a Windows native version of the kconfig-frontends tool, but that is not ready for prime time.
At this point, there are only a few options for the Windows user:
You can run the configuration tool using Cygwin. However, the Cygwin Makefile.win will complain so to do this will, you have to manually edit the .config file:
a. Delete the line: CONFIG_WINDOWS_NATIVE=y b. Change the apps/ directory path, CONFIG_APPS_DIR to use Unix style delimiters. For example, change "..\apps" to "../apps"
And of course, after you use the configuration tool you need to restore CONFIG_WINDOWS_NATIVE=y and the correct CONFIG_APPS_DIR.
2) You can, with some effort, run the the Cygwin kconfig-mconf tool directly in the Windows console window. In this case, you do not have to modify the .config file, but there are other complexities:
a. You need to temporarily set the Cgywin directories in the PATH variable then run kconfig-mconf manually like:
kconfig-mconf Kconfig
There is a Windows bacht file at tools/kconfig.bat that automates
these steps:
tools/kconfig menuconfigb. There is an issue with accessing DOS environment variables from the Cygwin kconfig-mconf running in the Windows console. The following change to the top-level Kconfig file seems to work around these problems:
config APPSDIR
string
- option env="APPSDIR"
+ default "../apps"TOOLCHAINS ^^^^^^^^^^
In order to build NuttX for your board, you will have to obtain a cross-
compiler to generate code for your target CPU. For each board,
configuration, there is a README.txt file (at configs/
In any case, the script, setenv.sh that was deposited in the top- level directory when NuttX was configured should be edited to set the path to where you installed the toolchain. The use of setenv.sh is optional but can save a lot of confusion in the future.
For many configurations, a DIY set of tools is available for NuttX. These tools can be downloaded from the NuttX SourceForge file repository. After unpacking the buildroot tarball, you can find instructions for building the tools in the buildroot/configs/README.txt file.
Check the README.txt file in the configuration director for your board
to see if you can use the buildroot toolchain with your board (this
README.txt file is located in configs/
This toolchain is available for both the Linux and Cygwin development environments.
Advantages: (1) NuttX header files are built into the tool chain, and (2) related support tools like NXFLAT tools and the ROMFS genromfs tools can be built into your toolchain.
Disadvantages: This tool chain is not was well supported as some other toolchains. GNU tools are not my priority and so the buildroot tools often get behind. For example, until recently there was no EABI support in the NuttX buildroot toolchain for ARM.
NOTE: For Cortex-M3/4, there are OABI and EABI versions of the buildroot toolchains. If you are using the older OABI toolchain the prefix for the tools will be arm-nuttx-elf-; for the EABI toolchin the prefix will be arm-nuttx-eabi-. If you are using the older OABI toolchain with an ARM Cortex-M3/4, you will need to set CONFIG_ARMV7M_OABI_TOOLCHAIN in the .config file in order to pick the right tool prefix.
If the make system ever picks the wrong prefix for your toolchain, you can always specify the prefix on the command to override the default like:
make CROSSDEV=arm-nuttx-elfSHELLS ^^^^^^
The NuttX build relies on some shell scripts. Some are inline in the Makefiles and many are exectuble scripts in the tools/. directory. The scripts were all developed using bash and many contain bash shell dependencies.
Most of the scripts begin with #!/bin/bash to specifically select the bash shell. Some still have #!/bin/sh but I haven't heard any complaints so these must not have bash dependencies.
There are two shell issues that I have heard of:
Linux where /bin/sh refers to an incompatible shell (like ksh or csh).
In this case, bash is probably avaiable and the #!/bin/bash at the beginning of the file should do the job. If any scripts with #!/bin/sh fail, try changing that ti #!/bin/bash and let me know about the change.
FreeBSD with the Bourne Shell and no bash shell.
The other, reverse case has also been reported on FreeBSD setups that have the Bourne shell, but not bash. In this base, #!/bin/bash fails but #!/bin/sh works okay. My recommendation in this case is to create a symbolic link at /bin/bash that refers to the Bourne shell.
There may still be issues, however, with certain the bash-centric scripts that will require modifications.
BUILDING NUTTX ^^^^^^^^^^^^^^
NuttX builds in-place in the source tree. You do not need to create any special build directories. Assuming that your Make.defs is setup properly for your tool chain and that setenv.sh contains the path to where your cross-development tools are installed, the following steps are all that are required to build NuttX:
cd ${TOPDIR}
. ./setenv.sh
makeAt least one configuration (eagle100) requires additional command line
arguments on the make command. Read ${TOPDIR}/configs/
Re-building is normally simple -- just type make again.
But there are some things that can "get you" when you use the Cygwin development environment with Windows native tools. The native Windows tools do not understand Cygwin's symbolic links, so the NuttX make system does something weird: It copies the configuration directories instead of linking to them (it could, perhaps, use the NTFS 'mklink' command, but it doesn't).
A consequence of this is that you can easily get confused when you edit a file in one of the linked (i.e., copied) directories, re-build NuttX, and then not see your changes when you run the program. That is because build is still using the version of the file in the copied directory, not your modified file! To work around this annoying behavior, do the following when you re-build:
make clean_context allThis 'make' command will remove of the copied directories, re-copy them, then make NuttX.
Build Targets: Below is a summary of the build targets available in the top-level NuttX Makefile:
all
The default target builds the NuttX executable in the selected output
formats.clean
Removes derived object files, archives, executables, and temporary
files, but retains the configuration and context files and directories.distclean
Does 'clean' then also removes all configuration and context files.
This essentially restores the directory structure to its original,
unconfigured stated.Application housekeeping targets. The APPDIR variable refers to the user application directory. A sample apps/ directory is included with NuttX, however, this is not treated as part of NuttX and may be replaced with a different application directory. For the most part, the application directory is treated like any other build directory in the Makefile script. However, as a convenience, the following targets are included to support housekeeping functions in the user application directory from the NuttX build directory.
apps_clean
Perform the clean operation only in the user application directoryapps_distclean
Perform the distclean operation only in the user application directory.
The apps/.config file is preserved so that this is not a "full" distclean
but more of a configuration "reset."export
The export target will package the NuttX libraries and header files into
an exportable package. Caveats: (1) These needs some extension for the KERNEL
build. (2) The logic in tools/mkexport.sh only supports GCC and, for example,
explicitly assumes that the archiver is 'ar'download
This is a helper target that will rebuild NuttX and download it to the target
system in one step. The operation of this target depends completely upon
implementation of the DOWNLOAD command in the user Make.defs file. It will
generate an error an error if the DOWNLOAD command is not defined.The following targets are used internally by the make logic but can be invoked from the command under certain conditions if necessary.
depend
Create build dependencies. (NOTE: There is currently no support for build
dependencies under Cygwin using Windows-native toolchains.)context
The context target is invoked on each target build to assure that NuttX is
properly configured. The basic configuration steps include creation of the
the config.h and version.h header files in the include/nuttx directory and
the establishment of symbolic links to configured directories.clean_context
This is part of the distclean target. It removes all of the header files
and symbolic links created by the context target.Build Options: Of course, the value any make variable an be overriden from the make command line. However, there is one particular variable assignment option that may be useful to you:
V=1
This is the build "verbosity flag." If you specify V=1 on the make command
line, you will see the exact commands used in the build. This can be very
useful when adding new boards or tracking down compile time errors and
warnings (Contributed by Richard Cochran).The beginnings of a Windows native build are in place but still not full usable as of this writing. The windows native build logic initiatiated if CONFIG_WINDOWS_NATIVE=y is defined in the NuttX configuration file:
This build:
- Uses all Windows style paths
- Uses primarily Windows batch commands from cmd.exe, with
- A few extensions from GNUWin32In this build, you cannot use a Cygwin or MSYS shell. Rather the build must be performed in a Windows console window. Here is a better terminal than the standard issue, CMD.exe terminal: ConEmu which can be downloaded from: http://code.google.com/p/conemu-maximus5/
Build Tools. The build still relies on some Unix-like commands. I use the GNUWin32 tools that can be downloaded from http://gnuwin32.sourceforge.net/.
Host Compiler: I use the MingGW GCC compiler which can be downloaded from http://www.mingw.org/. If you are using GNUWin32, then it is recommended the you not install the optional MSYS components as there may be conflicts.
This capability should still be considered a work in progress because:
(1) It has not been verfied on all targets and tools, and (2) it still lacks some of the creature-comforts of the more mature environments (like 'make menuconfig' support. See the section "NuttX Configuration Tool under DOS" above).
There is an alternative to the setenv.sh script available for the Windows native environment: tools/configure.bat. See tools/README.txt for additional information.
The Windows native build will depend upon a few Unix-like tools that can be provided either by MSYS or GNUWin32. The GNUWin32 are available from http://gnuwin32.sourceforge.net/. GNUWin32 provides ports of tools with a GPL or similar open source license to modern MS-Windows (Microsoft Windows 2000 / XP / 2003 / Vista / 2008 / 7). See http://gnuwin32.sourceforge.net/packages.html for a list of all of the tools available in the GNUWin32 package.
The SourceForge project is located here: http://sourceforge.net/projects/gnuwin32/. The project is still being actively supported (although some of the Windows ports have gotten very old).
Some commercial toolchains include a subset of the GNUWin32 tools in the installation. My recommendation is that you download the GNUWin32 tools directly from the sourceforge.net website so that you will know what you are using and can reproduce your build environment.
GNUWin32 Installation Steps:
The following steps will download and execute the GNUWin32 installer.
Download GetGNUWin32-x.x.x.exe from http://sourceforge.net/projects/getgnuwin32/files/. This is the installer. The current version as of this writing is 0.6.3.
Run the installer.
Accept the license.
Select the installation directory. My recommendation is the
directory that contains this README file (
After running GetGNUWin32-0.x.x.exe, you will have a new directory
Change to the directory created by GetGNUWin32-x.x.x.exe
cd GetGNUWin32
Execute the download.bat script. The download.bat script will download about 446 packages! Enough to have a very complete Linux-like environment under the DOS shell. This will take awhile. This step only downloads the packages and the next step will install the packages.
download
This step will install the downloaded packages. The argument of the install.bat script is the installation location. C:\gnuwin32 is the standard install location:
install C:\gnuwin32
NOTE: This installation step will install all GNUWin32 packages... far
more than you will ever need. If disc space is a problem for you, you might
need to perform a manual installation of the individual ZIP files that you
will find in the
CYGWIN BUILD PROBLEMS ^^^^^^^^^^^^^^^^^^^^^
If you see strange behavior when building under Cygwin then you may have a problem with your PATH variable. For example, if you see failures to locate files that are clearly present, that may mean that you are using the wrong version of a tool. For example, you may not be using Cygwin's 'make' program at /usr/bin/make. Try:
$ which make
/usr/bin/makeWhen you install some toolchains (such as Yargarto or CodeSourcery tools), they may modify your PATH variable to include a path to their binaries. At that location, they make have GNUWin32 versions of the tools. So you might actually be using a version of make that does not understand Cygwin paths.
The solution is either:
Put /usr/local/bin, /usr/bin, and /bin at the front of your path:
$ export PATH=/usr/local/bin:/usr/bin:/bin:$PATH
There are many popular Windows native toolchains that may be used with NuttX. Examples include CodeSourcery (for Windows), devkitARM, and several vendor- provied toolchains. There are several limitations with using a and Windows based toolchain in a Cygwin environment. The three biggest are:
The Windows toolchain cannot follow Cygwin paths. Path conversions are performed automatically in the Cygwin makefiles using the 'cygpath' utility but you might easily find some new path problems. If so, check out 'cygpath -w'
Windows toolchains cannot follow Cygwin symbolic links. Many symbolic links are used in Nuttx (e.g., include/arch). The make system works around these problems for the Windows tools by copying directories instead of linking them. But this can also cause some confusion for you: For example, you may edit a file in a "linked" directory and find that your changes had no effect. That is because you are building the copy of the file in the "fake" symbolic directory. If you use a Windows toolchain, you should get in the habit of making like this:
make clean_context all
An alias in your .bashrc file might make that less painful. The rebuild is not a long as you might think because there is no dependency checking if you are using a native Windows toolchain. That bring us to #3:
Dependencies are not made when using Windows versions of the GCC on a POSIX platform (i.e., Cygwin). This is because the dependencies are generated using Windows paths which do not work with the Cygwin make.
MKDEP = $(TOPDIR)/tools/mknulldeps.sh
If you are building natively on Windows, then no such conflict exists and the best selection is:
MKDEP = $(TOPDIR)/tools/mkdeps.exe
General Pre-built Toolchain Issues
To continue with the list of "Window Native Toolchain Issues" we can add the following. These, however, are really just issues that you will have if you use any pre-built toolchain (vs. building the NuttX toolchain from the NuttX buildroot package):
There may be incompatibilities with header files, libraries, and compiler built-in functions at detailed below. For the most part, these issues are handled in the existing make logic. But if you are breaking new ground, then you may incounter these:
Header Files. Most pre-built toolchains will build with a foreign C
library (usually newlib, but maybe uClibc or glibc if you are using a
Linux toolchain). This means that the header files from the foreign
C library will be built into the toolchain. So if you "include
This can cause really confusion in the buildds and you must always be sure the -nostdinc is included in the CFLAGS. That will assure that you take the include files only from
Libraries. What was said above header files applies to libraries. You do not want to include code from the libraries of any foreign C libraries built into your toolchain. If this happens you will get perplexing errors about undefined sysmbols. To avoid these errors, you will need to add -nostdlib to your CFLAGS flags to assure that you only take code from the NuttX libraries.
This, however, may causes other issues for libraries in the toolchain that you do want (like libgcc.a or libm.a). These are special-cased in most Makefiles, but you could still run into issues of missing libraries.
Built-Ins. Some compilers target a particular operating system. Many people would, for example, like to use the same toolchain to develop Linux and NuttX software. Compilers built for other operating systems may generate incompatible built-in logic and, for this reason, -fno-builtin should also be included in your C flags
And finally you may not be able to use NXFLAT.
NXFLAT. If you use a pre-built toolchain, you will lose all support for NXFLAT. NXFLAT is a binary format described in Documentation/NuttXNxFlat.html. It may be possible to build standalone versions of the NXFLAT tools; there are a few examples of this in the misc/buildroot/configs directory. However, it is possible that there could be interoperability issues with your toolchain since they will be using different versions of binutials and possibly different ABIs.
DOCUMENTATION ^^^^^^^^^^^^^
Additional information can be found in the Documentation/ directory and also in README files that are scattered throughout the source tree. The documentation is in HTML and can be access by loading the following file into your Web browser:
Documentation/index.html
NuttX documentation is also available online at http://www.nuttx.org.
Below is a guide to the available README files in the NuttX source tree:
| nuttx | - arch/ | ||
|---|---|---|---|
| - arm/ | |||
| `- src | |||
| `- lpc214x/README.txt | |||
| - avr/ | |||
| `- README.txt | |||
| - sh/ | |||
| - include/ | |||
| -m16c/README.txt | |||
| -sh1/README.txt | |||
| `-README.txt | |||
| - src/ | |||
| -common/README.txt | |||
| -m16c/README.txt | |||
| -sh1/README.txt | |||
| `-README.txt | |||
| - x86/ | |||
| - include/ | |||
| `-README.txt | |||
| `- src/ | |||
| `-README.txt | |||
| `- z80/ | |||
| `- src/ | |||
| - z80/README.txt | |||
| `- z180/README.txt, z180_mmu.txt | |||
| `- README.txt | |||
| - configs/ | |||
| - amber/ | |||
| `- README.txt | |||
| - arduino-due/ | |||
| `- README.txt | |||
| - avr32dev1/ | |||
| `- README.txt | |||
| - c5471evm/ | |||
| - include/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - cloudctrl | |||
| `- README.txt | |||
| - compal_e88 | |||
| `- README.txt | |||
| - compal_e99 | |||
| `- README.txt | |||
| - demo0s12ne64/ | |||
| `- README.txt | |||
| - ea3131/ | |||
| `- README.txt | |||
| - ea3152/ | |||
| `- README.txt | |||
| - eagle100/ | |||
| - include/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - ekk-lm3s9b96/ | |||
| `- README.txt | |||
| - ez80f910200kitg/ | |||
| - ostest/README.txt | |||
| `- README.txt | |||
| - ez80f910200zco/ | |||
| - dhcpd/README.txt | |||
| - httpd/README.txt | |||
| - nettest/README.txt | |||
| - nsh/README.txt | |||
| - ostest/README.txt | |||
| - poll/README.txt | |||
| `- README.txt | |||
| - fire-stm32v2/ | |||
| `- README.txt | |||
| - freedom-kl25z/ | |||
| `- README.txt | |||
| - hymini-stm32v/ | |||
| - include/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - kwikstik-k40/ | |||
| `- README.txt | |||
| - lincoln60/ | |||
| `- README.txt | |||
| - lm3s6432-s2e/ | |||
| - include/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - lm3s6965-ek/ | |||
| - include/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - lm3s8962-ek/ | |||
| - include/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - lpc4330-xplorer/ | |||
| `- README.txt | |||
| - lpcxpresso-lpc1768/ | |||
| `- README.txt | |||
| - m68332evb/ | |||
| - include/README.txt | |||
| `- src/README.txt | |||
| - mbed/ | |||
| `- README.txt | |||
| - mcu123-lpc214x/ | |||
| - include/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - micropendous3/ | |||
| `- README.txt | |||
| - mikroe-stm32f/ | |||
| `- README.txt | |||
| - mirtoo/ | |||
| `- README.txt | |||
| - mx1ads/ | |||
| - include/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - ne63badge/ | |||
| `- README.txt | |||
| - ntosd-dm320/ | |||
| - doc/README.txt | |||
| - include/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - nucleus2g/ | |||
| `- README.txt | |||
| - nutiny-nuc120/ | |||
| `- README.txt | |||
| - olimex-lpc1766stk/ | |||
| `- README.txt | |||
| - olimex-lpc2378/ | |||
| - include/README.txt | |||
| `- README.txt | |||
| - olimex-strp711/ | |||
| - include/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - open1788/ | |||
| `- README.txt | |||
| - p112/ | |||
| `- README.txt | |||
| - pcblogic-pic32mx/ | |||
| `- README.txt | |||
| - pic32-starterkit/ | |||
| `- README.txt | |||
| - pic32mx7mmb/ | |||
| `- README.txt | |||
| - pirelli_dpl10/ | |||
| `- README.txt | |||
| - pjrc-8051/ | |||
| - include/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - qemu-i486/ | |||
| - include/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - rgmp/ | |||
| - include/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - sama5d3x-ek/ | |||
| `- README.txt | |||
| - sam3u-ek/ | |||
| `- README.txt | |||
| - sam4l-xplained/ | |||
| `- README.txt | |||
| - sam4s-xplained/ | |||
| `- README.txt | |||
| - sim/ | |||
| - include/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - shenzhou/ | |||
| `- README.txt | |||
| - skp16c26/ | |||
| - include/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - stm3210e-eval/ | |||
| - include/README.txt | |||
| - RIDE/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - stm3220g-eval/ | |||
| `- README.txt | |||
| - stm3240g-eval/ | |||
| `- README.txt | |||
| - stm32_tiny/ | |||
| `- README.txt | |||
| - stm32f100rc_generic/ | |||
| `- README.txt | |||
| - stm32f3discovery/ | |||
| `- README.txt | |||
| - stm32f4discovery/ | |||
| `- README.txt | |||
| - stm32ldiscovery/ | |||
| `- README.txt | |||
| - sure-pic32mx/ | |||
| `- README.txt | |||
| - teensy/ | |||
| `- README.txt | |||
| - twr-k60n512/ | |||
| `- README.txt | |||
| - ubw32/ | |||
| `- README.txt | |||
| - us7032evb1/ | |||
| - bin/README.txt | |||
| - include/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - vsn/ | |||
| - src/README.txt | |||
| `- README.txt | |||
| - xtrs/ | |||
| - include/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - z16f2800100zcog/ | |||
| - ostest/README.txt | |||
| - pashello/README.txt | |||
| `- README.txt | |||
| - z80sim/ | |||
| - include/README.txt | |||
| - src/README.txt | |||
| `- README.txt | |||
| - z8encore000zco/ | |||
| - ostest/README.txt | |||
| `- README.txt | |||
| - z8f64200100kit/ | |||
| - ostest/README.txt | |||
| `- README.txt | |||
| - zkit-arm-1769/ | |||
| `- README.txt | |||
| - zp214xpa/ | |||
| `- README.txt | |||
| `- README.txt | |||
| - drivers/ | |||
| - lcd/ | |||
| `- README.txt | |||
| - sercomm/ | |||
| `- README.txt | |||
| - syslog/ | |||
| `- README.txt | |||
| `- README.txt | |||
| - fs/ | |||
| - mmap/ | |||
| `- README.txt | |||
| `- nxffs/ | |||
| `- README.txt | |||
| - graphics/ | |||
| `- README.txt | |||
| - lib/ | |||
| `- README.txt | |||
| - libc/ | |||
| `- README.txt | |||
| - libxx/ | |||
| `- README.txt | |||
| - mm/ | |||
| `- README.txt | |||
| - syscall/ | |||
| `- README.txt |
- tools/ - README.txt
apps
|- examples/
| |- json/README.txt
| |- pashello/README.txt
| - README.txt |- graphics/ |- tiff/README.txt
|- interpreters/
| |- ficl
| | - README.txt |- README.txt
|- modbus/
| - README.txt |- netutils/ | |- discover | |- README.txt
| |- ftpc
| | - README.txt | |- json | |- README.txt
| |- telnetd
| | - README.txt |- README.txt
|- nshlib/
| - README.txt |- NxWidgets/ |- README.txt
|- system/
| |- i2c
| | - README.txt | |- install | |- README.txt
| - zmodem |- README.txt
`- README.txt
NxWidgets
|- Doxygen
| - README.txt |- tools |- README.txt
|- UnitTests
| - README.txt - README.txt