15.5. Configuration

The RTEMS Source Builder has two types of configuration data:

• Build Sets

• Package Build Configurations

By default these files can be located in two separate directories and searched. The first directory is config in your current working directory (_topdir) and the second is config located in the base directory of the RTEMS Source Builder command you run (_sbdir). The RTEMS directory rtems` located at the top of the RTEMS Source Builder source code is an example of a specific build configuration directory. You can create custom or private build configurations and if you run the RTEMS Source Builder command from that directory your configurations will be used.

The configuration search path is a macro variable and is reference as %{_configdir}. It’s default is defined as:

_configdir   : dir  optional  %{_topdir}/config:%{_sbdir}/config

Items:

1. The _topdir is the directory you run the command from and _sbdir is the location of the RTEMS Source Builder command.

2. A macro definition in a macro file has 4 fields, the label, type, constraint and the definition.

Build set files have the file extension .bset and the package build configuration files have the file extension of .cfg. The sb-set-builder command will search for build sets.

Both types of configuration files use the # character as a comment character. Anything after this character on the line is ignored. There is no block comment.

15.5.1. Source and Patches

The RTEMS Source Builder provides a flexible way to manage source. Source and patches are declare in configurations file using the source and patch directives. These are a single line containing a Universal Resource Location or URL and can contain macros and shell expansions. The %prep section details the source and patch directives

The URL can reference remote and local source and patch resources. The following schemes are provided:

http:

Remote access using the HTTP protocol.

https:

Remote access using the Secure HTTP protocol.

ftp:

Remote access using the FTP protocol.

git:

Remote access to a GIT repository.

pm:

Remote access to a patch management repository.

file:

Local access to an existing source directory.

15.5.1.1. HTTP, HTTPS, and FTP

Remote access to TAR or ZIP files is provided using HTTP, HTTPS and FTP protocols. The full URL provided is used to access the remote file including any query components. The URL is parsed to extract the file component and the local source directory is checked for that file. If the file is located locally the remote file is not downloaded. Currently no other checks are made. If a download fails you need to manually remove the file from the source directory and start the build process again.

The URL can contain macros. These are expanded before issuing the request to download the file. The standard GNU GCC compiler source URL is:

%source set gcc ftp://ftp.gnu.org/gnu/gcc/gcc-%{gcc_version}/gcc-%{gcc_version}.tar.bz2

Items:

1. The %source command’s set command sets the source. The first is set and following sets are ignored.

2. The source package is part of the gcc group.

The type of compression is automatically detected from the file extension. The supported compression formats are:

gz:

GNU ZIP

bzip2:

BZIP2

zip:

ZIP

xz:

XZ

The output of the decompression tool is fed to the standard tar utility if not a ZIP file and unpacked into the build directory. ZIP files are unpacked by the decompression tool and all other files must be in the tar file format.

The %source directive typically supports a single source file tar or zip file. The set command is used to set the URL for a specific source group. The first set command encountered is registered and any further set commands are ignored. This allows you to define a base standard source location and override it in build and architecture specific files. You can also add extra source files to a group. This is typically done when a collection of source is broken down in a number of smaller files and you require the full package. The source’s setup command must reside in the %prep: section and it unpacks the source code ready to be built.

If the source URL references the GitHub API server a tarball of the specified version is download. For example the URL for a Newlib snapshot GitHub is:

%define newlib_version 08eab6396f678cf5e5968acaed0bae9fd129983b
%define newlib_external 1
%define newlib_expand_name sourceware-mirror-newlib-cygwin-%{newlib_version}
%source set newlib --rsb-file=newlib-%{newlib_version}.tar.gz \
   https://codeload.github.com/RTEMS/sourceware-mirror-newlib-cygwin/tar.gz/%{newlib_version}

15.5.1.2. GIT

A GIT repository can be cloned and used as source. The GIT repository resides in the ‘source’ directory under the git directory. You can edit, update and use the repository as you normally do and the results will used to build the tools. This allows you to prepare and test patches in the build environment the tools are built in. The GIT URL only supports the GIT protocol. You can control the repository via the URL by appending options and arguments to the GIT path. The options are delimited by ? and option arguments are delimited from the options with =. The options are:

protocol:

Use a specific protocol. The supported values are ssh, git, http, https, ftp, ftps, rsync, and none.

branch:

Checkout the specified branch.

pull:

Perform a pull to update the repository.

fetch:

Perform a fetch to get any remote updates.

reset:

Reset the repository. Useful to remove any local changes. You can pass the hard argument to force a hard reset.

An example is:

%source set gcc git://gcc.gnu.org/git/gcc.git?branch=gcc-4_7-branch?reset=hard

This will clone the GCC git repository and checkout the 4.7-branch and perform a hard reset. You can select specific branches and apply patches. The repository is cleaned up before each build to avoid various version control errors that can arise.

The protocol option lets you set a specific protocol. The git:// prefix used by the RSB to select a git repository can be removed using none or replaced with one of the standard git protocols.

15.5.2. Macros and Defaults

The RTEMS Source Builder uses tables of macros read in when the tool runs. The initial global set of macros is called the defaults. These values are read from a file called defaults.mc and modified to suite your host. This host specific adaption lets the Source Builder handle differences in the build hosts.

Build set and configuration files can define new values updating and extending the global macro table. For example builds are given a release number. This is typically a single number at the end of the package name. For example:

%define release 1

Once defined if can be accessed in a build set or package configuration file with:

%{release}

The sb-defaults command lists the defaults for your host. I will not include the output of this command because of its size:

$ ../source-builder/sb-defaults

A nested build set is given a separate copy of the global macro maps. Changes in one change set are not seen in other build sets. That same happens with configuration files unless inline includes are used. Inline includes are seen as part of the same build set and configuration and changes are global to that build set and configuration.

15.5.2.1. Macro Maps and Files

Macros are read in from files when the tool starts. The default settings are read from the defaults macro file called defaults.mc located in the top level RTEMS Source Builder command directory. User macros can be read in at start up by using the --macros command line option.

The format for a macro in macro files is:

Name Type Attribute String

where Name is a case insensitive macro name, the Type field is:

none:

Nothing, ignore.

dir:

A directory path.

exe:

An executable path.

triplet:

A GNU style architecture, platform, operating system string.

the Attribute field is:

none:

Nothing, ignore

required:

The host check must find the executable or path.

optional:

The host check generates a warning if not found.

override:

Only valid outside of the global map to indicate this macro overrides the same one in the global map when the map containing it is selected.

undefine:

Only valid outside of the global map to undefine the macro if it exists in the global map when the map containing it is selected. The global map’s macro is not visible but still exists.

and the String field is a single or tripled multiline quoted string. The ‘String’ can contain references to other macros. Macro that loop are not currently detected and will cause the tool to lock up.

Maps are declared anywhere in the map using the map directive:

# Comments
[my-special-map] <1>
_host:  none, override, 'abc-xyz'
multiline: none, override, '''First line,
second line,
and finally the last line'''

Items:

1. The map is set to my-special-map.

Any macro definitions following a map declaration are placed in that map and the default map is global when loading a file. Maps are selected in configuration files by using the %select directive:

%select my-special-map

Selecting a map means all requests for a macro first check the selected map and if present return that value else the global map is used. Any new macros or changes update only the global map. This may change in future releases so please make sure you use the override attribute.

The macro files specified on the command line are looked for in the _configdir paths. See the definition of _configdir in Configuration for details. Included files need to add the %{_configdir} macro to the start of the file.

Macro map files can include other macro map files using the %include directive. The macro map to build binutils, gcc, newlib, gdb and RTEMS from version control heads is:

#
# Build all tool parts from version control head.
#
%include %{_configdir}/snapshots/binutils-head.mc
%include %{_configdir}/snapshots/gcc-head.mc
%include %{_configdir}/snapshots/newlib-head.mc
%include %{_configdir}/snapshots/gdb-head.mc

Items:

1. The file is config/snapshots/binutils-gcc-newlib-gdb-head.mc.

The macro map defaults to global at the start of each included file and the map setting of the macro file including the other macro files does not change.

15.5.2.2. Personal Macros

When the tools start to run they will load personal macros. Personal macros are in the standard format for macros in a file. There are two places personal macros can be configured. The first is the environment variable RSB_MACROS. If present the macros from the file the environment variable points to are loaded. The second is a file called .rsb_macros in your home directory. You need to have the environment variable HOME defined for this work.

15.5.3. Configuration Reports

A configuration report detailing a build configuration is generated by the sb-set-builder command. The report can also be generated separately from the build process by invoking the sb-report command on the build set used for the build, for example:

cd rtems
../source-builder/sb-reports 5/rtems-sparc
less 5-rtems-sparc.txt

15.5.3.1. Report Mailing

Configuration reports from a build can be mailed to a specific email address for logging and monitoring. Mailing requires a number of parameters to function. These are:

• To mail address

• From mail address

• SMTP host

The to mail address is taken from the macro %{_mail_tools_to} and the default is rtems-tooltestresults at rtems.org. You can override the default with a personal or user macro file or via the command line option --mail-to.

The from mail address is taken from:

• GIT configuration

• User .mailrc file

• Command line

If you have configured an email and name in git it will be used used. If you do not a check is made for a .mailrc file. The environment variable MAILRC is used if present else your home directory is check. If found the file is scanned for the from setting:

set from="Foo Bar <foo@bar>"

You can also support a from address on the command line with the --mail-from option.

The SMTP host is taken from the macro %{_mail_smtp_host} and the default is localhost. You can override the default with a personal or user macro file or via the command line option --smtp-host.

15.5.4. Build Set Files

Build set files lets you list the packages in the build set you are defining and have a file extension of .bset. Build sets can define macro variables, inline include other files and reference other build set or package configuration files.

Defining macros is performed with the %define macro:

%define _target m32r-rtems4.11

Inline including another file with the %include macro continues processing with the specified file returning to carry on from just after the include point:

%include rtems-4.11-base.bset

This includes the RTEMS 4.11 base set of defines and checks. The configuration paths as defined by _configdir are scanned. The file extension is optional.

You reference build set or package configuration files by placing the file name on a single line:

tools/rtems-binutils-2.22-1

The _configdir path is scanned for tools/rtems-binutils-2.22-1.bset or tools/rtems-binutils-2.22-1.cfg. Build set files take precedent over package configuration files. If tools/rtems-binutils-2.22-1 is a build set a new instance of the build set processor is created and if the file is a package configuration the package is built with the package builder. This all happens once the build set file has finished being scanned.

15.5.5. Configuration Control

The RTEMS Souce Builder is designed to fit within most verification and validation processes. All of the RTEMS Source Builder is source code. The Python code is source and comes with a commercial friendly license. All configuration data is text and can be read or parsed with standard text based tools.

File naming provides configuration management. A specific version of a package is captured in a specific set of configuration files. The top level configuration file referenced in a build set relates to a specific configuration of the package being built. For example the RTEMS configuration file rtems-gcc-4.7.2-newlib-2.0.0-1.cfg creates an RTEMS GCC and Newlib package where the GCC version is 4.7.2, the Newlib version is 2.0.0, plus any RTEMS specific patches that related to this version. The configuration defines the version numbers of the various parts that make up this package:

%define gcc_version    4.7.2
%define newlib_version 2.0.0
%define mpfr_version   3.0.1
%define mpc_version    0.8.2
%define gmp_version    5.0.5

The package build options, if there are any are also defined:

%define with_threads 1
%define with_plugin  0
%define with_iconv   1

The generic configuration may provide defaults in case options are not specified. The patches this specific version of the package requires can be included:

Patch0: gcc-4.7.2-rtems4.11-20121026.diff

Finally including the GCC 4.7 configuration script:

%include %{_configdir}/gcc-4.7-1.cfg

The gcc-4.7-1.cfg file is a generic script to build a GCC 4.7 compiler with Newlib. It is not specific to RTEMS. A bare no operating system tool set can be built with this file.

The -1 part of the file names is a revision. The GCC 4.7 script maybe revised to fix a problem and if this fix effects an existing script the file is copied and given a -2 revision number. Any dependent scripts referencing the earlier revision number will not be effected by the change. This locks down a specific configuration over time.

15.5.6. Personal Configurations

The RSB supports personal configurations. You can view the RTEMS support in the rtems directory as a private configuration tree that resides within the RSB source. There is also the bare set of configurations. You can create your own configurations away from the RSB source tree yet use all that the RSB provides.

To create a private configuration change to a suitable directory:

$ cd ~/work
$ mkdir test
$ cd test
$ mkdir config

and create a config directory. Here you can add a new configuration or build set file. The section ‘Adding New Configurations’ details how to add a new confguration.

15.5.7. New Configurations

This section describes how to add a new configuration to the RSB. We will add a configuration to build the Device Tree Compiler. The Device Tree Compiler or DTC is part of the Flattened Device Tree project and compiles Device Tree Source (DTS) files into Device Tree Blobs (DTB). DTB files can be loaded by operating systems and used to locate the various resources such as base addresses of devices or interrupt numbers allocated to devices. The Device Tree Compiler source code can be downloaded from http://www.jdl.com/software. The DTC is supported in the RSB and you can find the configuration files under the bare/config tree. I suggest you have a brief look over these files.

15.5.7.1. Layering by Including

Configurations can be layered using the %include directive. The user invokes the outer layers which include inner layers until all the required configuration is present and the package can be built. The outer layers can provide high level details such as the version and the release and the inner layers provide generic configuration details that do not change from one release to another. Macro variables are used to provide the specific configuration details.

15.5.7.2. Configuration File Numbering

Configuration files have a number at the end. This is a release number for that configuration and it gives us the ability to track a specific configuration for a specific version. For example lets say the developers of the DTC package change the build system from a single makefile to autoconf and automake between version 1.3.0 and version 1.4.0. The configuration file used to build the package would change have to change. If we did not number the configuration files the ability to build 1.1.0, 1.2.0 or 1.3.0 would be lost if we update a common configuration file to build an autoconf and automake version. For version 1.2.0 the same build script can be used so we can share the same configuration file between version 1.1.0 and version 1.2.0. An update to any previous release lets us still build the package.

15.5.7.3. Common Configuration Scripts

Common configuration scripts that are independent of version, platform and architecture are useful to everyone. These live in the Source Builder’s configuration directory. Currently there are scripts to build binutils, expat, DTC, GCC, GDB and libusb. These files contain the recipes to build these package without the specific details of the versions or patches being built. They expect to be wrapped by a configuration file that ties the package to a specific version and optionally specific patches.

15.5.7.4. DTC Example

We will be building the DTC for your host rather than a package for RTEMS. We will create a file called source-builder/config/dtc-1-1.cfg. This is a common script that can be used to build a specific version using a general recipe. The file name is dtc-1-1.cfg where the cfg extension indicates this is a configuration file. The first 1 says this is for the major release 1 of the package and the last 1 is the build configuration version.

The file starts with some comments that detail the configuration. If there is anything unusual about the configuration it is a good idea to add something in the comments here. The comments are followed by a check for the release. In this case if a release is not provided a default of 1 is used:

#
# DTC 1.x.x Version 1.
#
# This configuration file configure's, make's and install's DTC.
#

%if %{release} == %{nil}
%define release 1
%endif

The next section defines some information about the package. It does not effect the build and is used to annotate the reports. It is recommended this information is kept updated and accurate:

Name:      dtc-%{dtc_version}-%{_host}-%{release}
Summary:   Device Tree Compiler v%{dtc_version} for target %{_target} on host %{_host}
Version:   %{dtc_version}
Release:   %{release}
URL:       https://www.devicetree.org/
BuildRoot: %{_tmppath}/%{name}-root-%(%{__id_u} -n)

The next section defines the source and any patches. In this case there is a single source package and it can be downloaded using the HTTP protocol. The RSB knows this is GZip’ped tar file. If more than one package is needed, add them increasing the index. The gcc-8-1.cfg configuration contains examples of more than one source package as well as conditionally including source packages based on the outer configuration options:

#
# Source
#
%source set dtc https://www.kernel.org/pub/software/utils/dtc/dtc-%{dtc_version}.tar.gz

The remainder of the script is broken in to the various phases of a build. They are:

. Preparation . Building . Installing, and . Cleaning

Preparation is the unpacking of the source, applying any patches as well as any package specific set ups. This part of the script is a standard Unix shell script. Be careful with the use of % and $. The RSB uses % while the shell scripts use $.

A standard pattern you will observe is the saving of the build’s top directory. This is used instead of changing into a subdirectory and then changing to the parent when finished. Some hosts will change in a subdirectory that is a link however changing to the parent does not change back to the parent of the link rather it changes to the parent of the target of the link and that is something the RSB nor you can track easily. The RSB configuration script’s are a collection of various subtle issues so please ask if you are unsure why something is being done a particular way.

The preparation phase will often include source and patch setup commands. Outer layers can set the source package and add patches as needed while being able to use a common recipe for the build. Users can override the standard build and supply a custom patch for testing using the user macro command line interface:

#
# Prepare the source code.
#
%prep
  build_top=$(pwd)

  %source setup dtc -q -n dtc-v%{dtc_version}
  %patch setup dtc -p1

  cd ${build_top}

The configuration file gcc-common-1.cfg is a complex example of source preparation. It contains a number of source packages and patches and it combines these into a single source tree for building. It uses links to map source into the GCC source tree so GCC can be built using the single source tree method. It also shows how to fetch source code from version control. Newlib is taken directly from its CVS repository.

Next is the building phase and for the DTC example this is simply a matter of running make. Note the use of the RSB macros for commands. In the case of %{__make} it maps to the correct make for your host. In the case of BSD systems we need to use the BSD make and not the GNU make.

If your package requires a configuration stage you need to run this before the make stage. Again the GCC common configuration file provides a detailed example:

%build
  build_top=$(pwd)

  cd dtc-v%{dtc_version}

  %{build_build_flags}

  %{__make} PREFIX=%{_prefix}

  cd ${build_top}

You can invoke make with the macro %{?_smp_flags} as a command line argument. This macro is controlled by the --jobs command line option and the host CPU detection support in the RSB. If you are on a multicore host you can increase the build speed using this macro. It also lets you disabled building on multicores to aid debugging when testing.

Next is the install phase. This phase is a little more complex because you may be building a tar file and the end result of the build is never actually installed into the prefix on the build host and you may not even have permissions to perform a real install. Most packages install to the prefix and the prefix is typically supplied via the command to the RSB or the package’s default is used. The default can vary depending on the host’s operating system. To install to a path that is not the prefix the DESTDIR make variable is used. Most packages should honour the DESTDIR make variables and you can typically specify it on the command line to make when invoking the install target. This results in the package being installed to a location that is not the prefix but one you can control. The RSB provides a shell variable called SB_BUILD_ROOT you can use. In a build set where you are building a number of packages you can collect all the built packages in a single tree that is captured in the tar file.

Also note the use of the macro %{__rmdir}. The use of these macros allow the RSB to vary specific commands based on the host. This can help on hosts like Windows where bugs can effect the standard commands such as rm. There are many many macros to help you. You can find these listed in the defaults.mc file and in the trace output. If you are new to creating and editing configurations learning these can take a little time:

%install
  build_top=$(pwd)

  %{__rmdir} -rf $SB_BUILD_ROOT

  cd dtc-v%{dtc_version}
  %{__make} DESTDIR=$SB_BUILD_ROOT PREFIX=%{_prefix} install

  cd ${build_top}

Finally there is an optional clean section. The RSB will run this section if --no-clean has not been provided on the command line. The RSB does clean up for you.

To have a package installed automatically create a build set. A build set can build one or more packages from their configurations at once to create a single package. For example the GNU tools is typically seen as binutils, GCC and GDB and a build set will build each of these packages and create a single build set tar file or install the tools on the host into the prefix path.

The DTC build set file is called dtc.bset and contains:

#
# Build the DTC.
#

%define release 1

devel/dtc-1.2.0.cfg

To build this you can use something similar to:

$ ../source-builder/sb-set-builder --prefix=/usr/local --log=log_dtc \
   --trace --bset-tar-file --no-install dtc
RTEMS Source Builder - Set Builder, v0.2.0
Build Set: dtc
config: devel/dtc-1.2.0.cfg
package: dtc-1.2.0-x86_64-freebsd9.1-1
building: dtc-1.2.0-x86_64-freebsd9.1-1
tarball: tar/x86_64-freebsd9.1-dtc-set.tar.bz2
cleaning: dtc-1.2.0-x86_64-freebsd9.1-1
Build Set: Time 0:00:02.865758
$ ls tar
dtc-1.2.0-x86_64-freebsd9.1-1.tar.bz2   x86_64-freebsd9.1-dtc-set.tar.bz2

The build is for a FreeBSD host and the prefix is for user installed packages. In this example I cannot let the source builder perform the install because I never run the RSB with root privileges so a build set or bset tar file is created. This can then be installed using root privileges.

The command also supplies the --trace option. The output in the log file will contain all the macros.

15.5.7.5. Debugging

New configuration files require debugging. There are two types of debugging. The first is debugging RSB script bugs. The --dry-run option is used here. Suppling this option will result in most of the RSB processing to be performed and suitable output placed in the log file. This with the --trace option should help you resolve any issues.

The second type of bug to fix are related to the execution of one of phases. These are usually a mix of shell script bugs or package set up or configuration bugs. Here you can use any normal shell script type debug technique such as set +x to output the commands or echo statements. Debugging package related issues may require you start a build with the RSB and supply --no-clean option and then locate the build directories and change directory into them and manually run commands until to figure what the package requires.

15.5.8. Scripting

Configuration files specify how to build a package. Configuration files are scripts and have a .cfg file extension. The script format is based loosely on the RPM spec file format however the use and purpose in this tool does not compare with the functionality and therefore the important features of the spec format RPM needs and uses.

The script language is implemented in terms of macros. The built-in list is:

%{}:

Macro expansion with conditional logic.

%():

Shell expansion.

%prep:

The source preparation shell commands.

%build:

The build shell commands.

%install:

The package install shell commands.

%clean:

The package clean shell commands.

%include:

Inline include another configuration file.

%name:

The name of the package.

%summary:

A brief package description. Useful when reporting about a build.

%release:

The package release. A number that is the release as built by this tool.

%version:

The package’s version string.

%buildarch:

The build architecture.

%source:

Define a source code package. This macro has a number appended.

%patch:

Define a patch. This macro has a number appended.

%hash:

Define a checksum for a source or patch file.

%{echo message}:

Print the following string as a message.

%{warning message}:

Print the following string as a warning and continue.

%{error message}:

Print the following string as an error and exit.

%select:

Select the macro map. If there is no map nothing is reported.

%define:

Define a macro. Macros cannot be redefined, you must first undefine it.

%undefine:

Undefine a macro.

%if:

Start a conditional logic block that ends with a %endif.

%ifn:

Inverted start of a conditional logic block.

%ifarch:

Test the architecture against the following string.

%ifnarch:

Inverted test of the architecture

%ifos:

Test the host operating system.

%else:

Start the else conditional logic block.

%endfi:

End the conditional logic block.

%bconf_with:

Test the build condition with setting. This is the --with-* command line option.

%bconf_without:

Test the build condition without setting. This is the --without-* command line option.

15.5.8.1. Expanding

A macro can be %{string} or the equivalent of %string. The following macro expansions supported are:

%{string}:

Expand the ‘string’ replacing the entire macro text with the text in the table for the entry ‘string . For example if ‘var’ is ‘foo’ then ${var} would become foo.

%{expand: string}:

Expand the ‘string’ and then use it as a string to the macro expanding the macro. For example if foo is set to bar and bar is set to foobar then %{expand:foo} would result in foobar. Shell expansion can also be used.

%{with string}:

Expand the macro to 1 if the macro with_string is defined else expand to 0. Macros with the name with_string can be define with command line arguments to the RTEMS Source Builder commands.

%{defined string}:

Expand the macro to 1 if a macro of name string is defined else expand to ‘0’.

%{?string: expression}:

Expand the macro to expression if a macro of name string is defined else expand to %{nil}.

%{!?string: expression}:

Expand the macro to expression if a macro of name string is not defined. If the macro is define expand to %{nil}.

%(expression):

Expand the macro to the result of running the expression in a host shell. It is assumed this is a Unix type shell. For example %(whoami) will return your user name and %(date) will return the current date string.

15.5.8.2. %prep

The %prep macro starts a block that continues until the next block macro. The prep or preparation block defines the setup of the package’s source and is a mix of RTEMS Source Builder macros and shell scripting. The sequence is typically %source macros for source, %patch macros to patch the source mixed with some shell commands to correct any source issues:

%source setup gcc -q -c -T -n %{name}-%{version}

Items:

1. The source group to set up is gcc.

2. The source’s name is the macro %{name}.

3. The version of the source is the macro %{version}.

The source set up are declared with the source set and add commands. For example:

%source set gdb http://ftp.gnu.org/gnu/gdb/gdb-%{gdb_version}.tar.bz2

This URL is the primary location of the GNU GDB source code and the RTEMS Source Builder can download the file from this location and by inspecting the file extension use bzip2 decompression with tar. When the %prep section is processed a check of the local source directory is made to see if the file has already been downloaded. If not found in the source cache directory the package is downloaded from the URL. You can append other base URLs via the command line option --url. This option accepts a comma delimited list of sites to try.

You could optionally have a few source files that make up the package. For example GNU’s GCC was a few tar files for a while and it is now a single tar file. Support for multiple source files can be conditionally implemented with the following scripting:

%source set gcc ftp://ftp.gnu.org/gnu/gcc/gcc-%{gcc_version}/gcc-code-%{gcc_version}.tar.bz2
%source add gcc ftp://ftp.gnu.org/gnu/gcc/gcc-%{gcc_version}/gcc-g++-%{gcc_version}.tar.bz2
%source setup gcc -q -T -D -n gcc-%{gcc_version}

Separate modules use separate source groups. The GNU GCC compiler for RTEMS uses Newlib, MPFR, MPC, and GMP source packages. You define the source with:

%source set gcc ftp://ftp.gnu.org/gnu/gcc/gcc-%{gcc_version}/gcc-%{gcc_version}.tar.bz2
%source set newlib ftp://sourceware.org/pub/newlib/newlib-%{newlib_version}.tar.gz
%source set mpfr http://www.mpfr.org/mpfr-%{mpfr_version}/mpfr-%{mpfr_version}.tar.bz2
%source set mpc http://www.multiprecision.org/mpc/download/mpc-%{mpc_version}.tar.gz
%source set gmp ftp://ftp.gnu.org/gnu/gmp/gmp-%{gmp_version}.tar.bz2

and set up with:

%source setup gcc -q -n gcc-%{gcc_version}
%source setup newlib -q -D -n newlib-%{newlib_version}
%source setup mpfr -q -D -n mpfr-%{mpfr_version}
%source setup mpc -q -D -n mpc-%{mpc_version}
%source setup gmp -q -D -n gmp-%{gmp_version}

Patching also occurs during the preparation stage. Patches are handled in a similar way to the source packages except you only add patches. Patches are applied using the setup command. The setup command takes the default patch option. You can provide options with each patch by adding them as arguments before the patch URL. Patches with no options uses the setup default.

%patch add gdb %{rtems_gdb_patches}/gdb-sim-arange-inline.diff
%patch add gdb -p0 %{rtems_gdb_patches}/gdb-sim-cgen-inline.diff

Items:

1. This patch has the custom option of -p0.

To apply these patches:

%patch setup gdb -p1

Items:

1. The default options for gdb set up.

15.5.8.3. %build

The %build macro starts a block that continues until the next block macro. The build block is a series of shell commands that execute to build the package. It assumes all source code has been unpacked, patch and adjusted so the build will succeed.

The following is an example take from the GitHub STLink project. The STLink is a JTAG debugging device for the ST ARM family of processors:

%build
  export PATH="%{_bindir}:${PATH}"

  cd texane-stlink-%{stlink_version}

  ./autogen.sh

%if "%{_build}" != "%{_host}"
  CFLAGS_FOR_BUILD="-g -O2 -Wall" \
%endif
  CPPFLAGS="-I $SB_TMPPREFIX/include/libusb-1.0" \
  CFLAGS="$SB_OPT_FLAGS" \
  LDFLAGS="-L $SB_TMPPREFIX/lib" \
  ./configure \
    --build=%{_build} --host=%{_host} \
    --verbose \
    --prefix=%{_prefix} --bindir=%{_bindir} \
    --exec-prefix=%{_exec_prefix} \
    --includedir=%{_includedir} --libdir=%{_libdir} \
    --mandir=%{_mandir} --infodir=%{_infodir}

  %{__make} %{?_smp_mflags} all

  cd ..

Items:

1. Set up the PATH environment variable by setting the PATH environment variable. This is not always needed.

2. This package builds in the source tree texane-stlink-%{stlink_version} so enter it before building.

3. The package is actually checked directly out from the github project and so it needs its autoconf and automake files generated. Invoke the provided script autogen.sh

4. If the build machine and host are not the same the build is a cross-compile. Update the flags for a cross-compiled build.

5. The flags set in the environment before configure are various settings that need to be passed to customise the build. In this example an include path is being set to the install point of libusb. This package requires libusb is built before it.

6. The configure command. The RTEMS Source Builder provides all the needed paths as macro variables. You just need to provide them to configure.

7. Run make. Do not use make directly, use the RTEMS Source Builder’s defined value. This value is specific to the host. A large number of packages need GNU make and on BSD systems this is gmake. You can optionally add the SMP flags if the packages build system can handle parallel building with multiple jobs. The _smp_mflags value is automatically setup for SMP hosts to match the number of cores the host has.

15.5.8.4. %install

The %install macro starts a block that continues until the next block macro. The install block is a series of shell commands that execute to install the package. You can assume the package has built correctly when this block starts executing.

Never install the package to the actual prefix the package was built with. Always install to the RTEMS Source Builder’s temporary path defined in the macro variable __tmpdir. The RTEMS Source Builder sets up a shell environment variable called SB_BUILD_ROOT as the standard install point. Most packages support adding DESTDIR= to the make install command.

Looking at the same example as in %build:

%install
  export PATH="%{_bindir}:${PATH}" <1>
  rm -rf $SB_BUILD_ROOT <2>

  cd texane-stlink-%{stlink_version} <3>
  %{__make} DESTDIR=$SB_BUILD_ROOT install <4>

  cd ..

Items:

1. Setup the PATH environment variable. This is not always needed.

2. Clean any installed files. This makes sure the install is just what the package installs and not any left over files from a broken build or install.

3. Enter the build directory. In this example it just happens to be the source directory.

4. Run make install to install the package overriding the DESTDIR make variable.

15.5.8.5. %clean

The %clean macro starts a block that continues until the next block macro. The clean block is a series of shell commands that execute to clean up after a package has been built and install. This macro is currenly not been used because the RTEMS Source Builder automatically cleans up.

15.5.8.6. %include

The %include macro inline includes the specific file. The __confdir path is searched. Any relative path component of the include file is appended to each part of the __configdir. Adding an extension is optional as files with .bset and .cfg are automatically searched for.

Inline including means the file is processed as part of the configuration at the point it is included. Parsing continues from the next line in the configuration file that contains the %include macro.

Including files allow a kind of configuration file reuse. The outer configuration files provide specific information such as package version numbers and patches and then include a generic configuration script which builds the package:

%include %{_configdir}/gcc-4.7-1.cfg

15.5.8.7. %name

The name of the package being built. The name typically contains the components of the package and their version number plus a revision number. For the GCC with Newlib configuration the name is typically:

Name: %{_target}-gcc-%{gcc_version}-newlib-%{newlib_version}-%{release}

15.5.8.8. %summary

The %summary is a brief description of the package. It is useful when reporting. This information is not capture in the package anywhere. For the GCC with Newlib configuration the summary is typically:

Summary: GCC v%{gcc_version} and Newlib v%{newlib_version} for target %{_target} on host %{_host}

15.5.8.9. %release

The %release is a packaging number that allows revisions of a package to happen where no package versions change. This value typically increases when the configuration building the package changes:

%define release 1

15.5.8.10. %version

The %version macro sets the version the package. If the package is a single component it tracks that component’s version number. For example in the libusb configuration the %version is the same as %libusb_version, however in a GCC with Newlib configuration there is no single version number. In this case the GCC version is used:

Version: %{gcc_version}

15.5.8.11. %buildarch

The %buildarch macro is set to the architecture the package contains. This is currently not used in the RTEMS Source Builder and may go away. This macro is more important in a real packaging system where the package could end up on the wrong architecture.

15.5.8.12. %source

The %source macro has 3 commands that controls what it does. You can set the source files, add source files to a source group, and setup the source file group getting it ready to be used.

Source files are source code files in tar or zip files that are unpacked, copied or symbolically linked into the package’s build tree. Building a package requires one or more dependent packages. These are typically the packages source code plus dependent libraries or modules. You can create any number of these source groups and set each of them up with a separate source group for each needed library or module. Each source group normally has a single tar, zip or repository and the set defines this. Some projects split the source code into separate tar or zip files and you install them by using the add command.

The first instance of a set command creates the source group and sets the source files to be set up. Subsequent set commands for the same source group are ignored. this lets you define the standard source files and override them for specific releases or snapshots. To set a source file group:

%source set gcc ftp://ftp.gnu.org/gnu/gcc/gcc-%{gcc_version}/gcc-%{gcc_version}.tar.bz2

Items:

1. The source group is gcc.

To add another source package to be installed into the same source tree you use the add command:

%source add gcc ftp://ftp.gnu.org/gnu/gcc/gcc-%{gcc_version}/g++-%{gcc_version}.tar.bz2

The source setup command can only be issued in the %prep: section. The setup is:

%source gcc setup -q -T -D -n %{name}-%{version}

Accepted options are:

-n:

The -n option is used to set the name of the software’s build directory. This is necessary only when the source archive unpacks into a directory named other than <name>-<version>.

-c:

The -c option is used to direct %setup to create the top-level build directory before unpacking the sources.

-D:

The -D option is used to direct %setup to not delete the build directory prior to unpacking the sources. This option is used when more than one source archive is to be unpacked into the build directory, normally with the -b or -a options.

-T:

The -T option is used to direct %setup to not perform the default unpacking of the source archive specified by the first Source: macro. It is used with the -a or -b options.

-b <n>:

The -b option is used to direct %setup to unpack the source archive specified on the nth Source: macro line before changing directory into the build directory.

15.5.8.13. %patch

The %patch macro has the same 3 command as the %source command however the set commands is not really that useful with the %patch command. You add patches with the add command and setup applies the patches. Patch options can be added to each patch by placing them before the patch URL. If no patch option is provided the default options passed to the setup command are used. An option starts with a -. The setup command must reside inside the %prep section.

Patches are grouped in a similar way to the %source macro so you can control applying a group of patches to a specific source tree.

The __patchdir path is searched.

To add a patch:

%patch add gcc  gcc-4.7.2-rtems4.11-20121026.diff
%patch add gcc -p0  gcc-4.7.2-rtems4.11-20121101.diff

Items:

1. The patch group is gcc.

2. Option -p0 is this specific to this patch.

Placing %patch setup in the %prep section will apply the groups patches:

.. code-block:: spec

%patch setup gcc -p1

1. The patch group is gcc.

2. The default option used to apply the patch is -p1.

15.5.8.14. %hash

The %hash macro requires 3 arguments and defines a checksum for a specific file. The checksum is not applied until the file is checked before downloading and once downloaded. A patch or source file that does not have a hash defined generates a warning.

A file to be checksummed must be unique in the source and patch directories. The basename of the file is used as the key for the hash.

The hash algorthim can be md5, sha1, sha224, sha256, sha384, and sha512 and we typically use md5.

To add a hash:

%hash md5 <1> net-snmp-%{net_snmp_version}.tar.gz <2> 7db683faba037249837b226f64d566d4 <3>

Items:

1. The type of checksum.

2. The file to checksum. It can contain macros that are expanded for you.

3. The MD5 hash for the Net-SNMP file net-snmp-5.7.2.1.tar.gz.

Do not include a path with the file name. Only the basename is required. Files can be searched for from a number of places and having a path conponent would create confusion. This does mean files with hashes must be unique.

Downloading off repositories such as git and cvs cannot be checksummed. It is assumed those protocols and tools manage the state of the files.

15.5.8.15. %echo

The %echo macro outputs the following string to stdout. This can also be used as %{echo: message}.

15.5.8.16. %warning

The %warning macro outputs the following string as a warning. This can also be used as %{warning: message}.

15.5.8.17. %error

The %error macro outputs the follow string as an error and exits the RTEMS Source Builder. This can also be used as %{error: message}.

15.5.8.18. %select

The %select macro selects the map specified. If there is no map no error or warning is generated. Macro maps provide a simple way for a user to override the settings in a configuration file without having to edit it. The changes are recorded in the build report so they can be traced.

Configurations use different maps so macro overrides can target a specific package.

The default map is global:

%select gcc-4.8-snapshot <1>
%define one_plus_one 2 <2>

Items:

1. The map switches to gcc-4.8-snapshot. Any overrides in this map will be used.

2. Defining macros only updates the global map and not the selected map.

15.5.8.19. %define

The %define macro defines a new macro or updates an existing one. If no value is given it is assumed to be 1:

%define foo bar
%define one_plus_one 2
%define one <1>

Items:

1. The macro _one_ is set to 1.

15.5.8.20. %undefine

The %undefine macro removes a macro if it exists. Any further references to it will result in an undefine macro error.

15.5.8.21. %if

The %if macro starts a conditional logic block that can optionally have a else section. A test follows this macro and can have the following operators:

%{}	Check the macro is set or true, ie non-zero: %if ${foo} %warning The test passes, must not be empty or is non-zero %else %error The test fails, must be empty or zero %endif
!	The not operator inverts the test of the macro: %if ! ${foo} %warning The test passes, must be empty or zero %else %error The test fails, must not be empty or is non-zero %endif
==	The left hand size must equal the right hand side. For example: %define one 1 %if ${one} == 1 %warning The test passes %else %error The test fails %endif You can also check to see if a macro is empty: %if ${nothing} == %{nil} %warning The test passes %else %error The test fails
!=	The left hand size does not equal the right hand side. For example: # # Check a value not being equal. # %define one 1 %if ${one} != 2 %warning The test passes %else %error The test fails %endif # # Check if a macro is set. # %if ${something} != %{nil} %warning The test passes %else %error The test fails %endif
>	The left hand side is numerically greater than the right hand side.
>	The left hand side is numerically greater than or equal to the right hand side.
<	The left hand side is numerically less than the right hand side.
<=	The left hand side is numerically less than or equal to the right hand side.

15.5.8.22. %ifn

The %ifn macro inverts the normal %if logic. It avoids needing to provide empty if blocks followed by else blocks. It is useful when checking if a macro is defined:

%ifn %{defined foo}
 %define foo bar
%endif

15.5.8.23. %ifarch

The %ifarch is a short cut for %if %{_arch} == i386. Currently not used.

15.5.8.24. %ifnarch

The %ifnarch is a short cut for %if %{_arch} != i386. Currently not used.

15.5.8.25. %ifos

The %ifos is a short cut for %if %{_os} != mingw32. It allows conditional support for various operating system differences when building packages.

15.5.8.26. %else

The %else macro starts the conditional else block.

15.5.8.27. %endfi

The %endif macro ends a conditional logic block.

15.5.8.28. %bconf_with

The %bconf_with macro provides a way to test if the user has passed a specific option on the command line with the --with-<label> option.

15.5.8.29. %bconf_without

The %bconf_without macro provides a way to test if the user has passed a specific option on the command line with the --without-<label> option.