The graphical interface accesses all the functionality of the command-line tool and may be accessed from the menu option Tools → Administration. You will first be prompted to save your existing configuration before the dialog in Figure 27.1, “ Package Administration ” is displayed.

Figure 27.1.  Package Administration

The dialog displays the packages which are currently installed in the form of a tree. The installed versions of each package may be examined by expanding the tree.

Packages within a package distribution file (traditionally with a .epk suffix) may be added to the eCos repository or, if using multiple repositories, the top-most repository by clicking on the Add button. You will be prompted to provide the location of of the .epk package distribution file via a File Open dialog box.

Packages may be removed by selecting a package in the tree and then clicking on the Remove button. If a package node is selected, all versions of the selected package will be removed. If a package version node is selected, only the selected version of the package will be removed.

The ecosadmin.tcl script is located in the base of the eCos repository in the packages sub-directory. The command operates by default on the eCos repository pointed to by the environment variable ECOS_REPOSITORY. Use a command of the following form:

$ tclsh ecosadmin.tcl <command>

The following commands are available:

	Warning
	It is possible to remove critical packages such as the common HAL package using this tool. Users should take care to avoid such errors since core eCos packages may only be re-installed in the context of a complete re-installation of eCos.

All commands above take the option --repository=PATH_TO_REPOSITORY to provide the path to the repository that is to be operated on. The default is the value of the ECOS_REPOSITORY environment variable.

Many developers have their own source code control system, version control system or equivalent, and will want to use it with eCos and eCosPro sources. Since new releases of eCos and eCosPro come with different pathnames for all the source files, a little work is necessary to import a new release into your source repository.

For example, eCosCentric maintains eCosPro within Mercurial, a distributed source revision control system, using a number of source repositories with all package versions as current. An eCosPro release is constructed by merging all repositories into a new single release directory and renaming all current directories to <version>, as well as setting the <version> of all templates.

An eCosPro release may therefore be returned into a source revision control system by renaming all <version> directories below packages back to current and committing the resulting directory structure into the repository.

“current” is recommended because ecosconfig recognizes it and places it first in any list of versions.

For example, within a POSIX shell environment such as bash (normally available under Linux and provided with the eCosPro host tools for Windows hosts) use the following command:

find . -name <version> -type d -printf 'mv %p %h/current\n' | bash

Having carried out such a renaming operation, your source tree will now look like this:

BASE_DIR/kernel/current/include/
BASE_DIR/kernel/current/src/
BASE_DIR/kernel/current/tests/
...
BASE_DIR/compat/uitron/current/include/
BASE_DIR/compat/uitron/current/src/
BASE_DIR/compat/uitron/current/tests/

which is a suitable format for import into your own source code control system. When you get a subsequent release of eCosPro, do the same thing and use your own source code control system to manage the new source base, by importing the new version from

NEW_BASE_DIR/kernel/current/include/

and so on.

The eCos build tool will now offer only the “current” version of each package; select this for the packages you wish to use.

Alternatively you may choose to create two versions of each package with each <version> directory lying alongside the next and current containing the most recent <version>. For example:

cd $ECOS_REPOSITORY
find . -name <version> -type d -printf 'cp -r %p %h/current\n' | bash

Having carried out such a copy operation, your source tree will now look like this:

BASE_DIR/kernel/current/include/
BASE_DIR/kernel/<version>/include/
BASE_DIR/kernel/current/src/
BASE_DIR/kernel/<version>/src/
BASE_DIR/kernel/current/tests/
BASE_DIR/kernel/<version>/tests/
...
BASE_DIR/compat/uitron/current/include/
BASE_DIR/compat/uitron/<version>/include/
BASE_DIR/compat/uitron/current/src/
BASE_DIR/compat/uitron/<version>/src/
BASE_DIR/compat/uitron/current/tests/
BASE_DIR/compat/uitron/<version>/tests/

In simple terms, while you initially may have two identical version directories, when you overlay a new version on top of an existing directory tree, the older files within current will be replaced by the newer <version>. Within your configuration, however, all packages marked to use the older version will remain fixed while those marked to use current will switch to a newer version.

The above method of overlaying directories however is strongly discouraged. For example, the file ecos.db is not versioned and is common to both releases' packages directories so only the last version of the file will be retained with the contents of previous versions lost. In addition, common target definitions within ecos.db may differ between releases.

To work around these issues, developers are strongly advised to use the merge command of the ecosadmin.tcl tool which will merge the two versions of ecos.db in addition to overlaying new <version> subdirectories into the target repository. In addition, while merge will copy over the newer <version> subdirectories it will not replace the contents of pre-existing subdirectories such as current. This may, however, be made an option in a newer release of the ecosadmin.tcl tool and currently can be overcome through the following commands:

cd NEW_REPOSITORY
find . -name <version> -type d -printf 'cp -rf %p/. $ECOS_REPOSITORY/%h/current\n' | bash

	Note
	For the example given, the updated target definition in the merged repository will require use of the new device driver not present in the older release as a result of the updated target definition within ecos.db.

Warning

Making such a change has implications for any build trees you already have in use. A configured build tree contains information about the selected packages and their selected versions. Changing the name of the “versioning” folder in the source tree invalidates this information, and in consequence it also invalidates any local configuration options you have set up in this build tree. So if you want to change the version information in the source tree, do it first, before investing any serious time in configuring and building your system. When you create a new build tree to deal with the new source layout, it will contain default settings for all the configuration options, just like the old build tree did before you configured it. You will need to redo that configuration work in the new tree. Moving source code around also invalidates debugging information in any programs or libraries built from the old tree; these will need to be rebuilt.