Application version management
Zephyr supports an application version management system for applications which is built around the system that Zephyr uses for its own version system management. This allows applications to define a version file and have application (or module) code include the auto-generated file and be able to access it, just as they can with the kernel version. This version information is available from multiple scopes, including:
Code (C/C++)
Kconfig
CMake
which makes it a very versatile system for lifecycle management of applications. In addition, it can be used when building applications which target supported bootloaders (e.g. MCUboot) allowing images to be signed with correct version of the application automatically - no manual signing steps are required.
VERSION file
Application version information is set on a per-application basis in a file named VERSION,
which must be placed at the base directory of the application, where the CMakeLists.txt file is
located. This is a simple text file which contains the various version information fields, each on
a newline. The basic VERSION file has the following structure:
VERSION_MAJOR =
VERSION_MINOR =
PATCHLEVEL =
VERSION_TWEAK =
EXTRAVERSION =
Each field and the values it supports is described below. Zephyr limits the value of each numeric field to a single byte (note that there may be further restrictions depending upon what the version is used for, e.g. bootloaders might only support some of these fields or might place limits on the maximum values of fields):
Field |
Data type |
VERSION_MAJOR |
Numerical (0-255) |
VERSION_MINOR |
Numerical (0-255) |
PATCHLEVEL |
Numerical (0-255) |
VERSION_TWEAK |
Numerical (0-255) |
EXTRAVERSION |
Alphanumerical (Lowercase a-z and 0-9) |
When an application is configured using CMake, the version file will be automatically processed, and will be checked automatically each time the version is changed, so CMake does not need to be manually re-ran for changes to this file.
For the sections below, examples are provided for the following VERSION file:
VERSION_MAJOR = 1
VERSION_MINOR = 2
PATCHLEVEL = 3
VERSION_TWEAK = 4
EXTRAVERSION = unstable
Use in code
To use the version information in application code, the version file must be included, then the
fields can be freely used. The include file name is app_version.h (no path is needed), the
following defines are available:
Define |
Type |
Field(s) |
Example |
APPVERSION |
Numerical |
|
0x1020304 |
APP_VERSION_NUMBER |
Numerical |
|
0x10203 |
APP_VERSION_MAJOR |
Numerical |
|
1 |
APP_VERSION_MINOR |
Numerical |
|
2 |
APP_PATCHLEVEL |
Numerical |
|
3 |
APP_TWEAK |
Numerical |
|
4 |
APP_VERSION_STRING |
String (quoted) |
|
“1.2.3-unstable” |
APP_VERSION_EXTENDED_STRING |
String (quoted) |
|
“1.2.3-unstable+4” |
APP_VERSION_TWEAK_STRING |
String (quoted) |
|
“1.2.3+4” |
APP_BUILD_VERSION |
String (unquoted) |
None (value of |
v3.3.0-18-g2c85d9224fca |
Use in Kconfig
The following variables are available for usage in Kconfig files:
Variable |
Type |
Field(s) |
Example |
$(VERSION_MAJOR) |
Numerical |
|
1 |
$(VERSION_MINOR) |
Numerical |
|
2 |
$(PATCHLEVEL) |
Numerical |
|
3 |
$(VERSION_TWEAK) |
Numerical |
|
4 |
$(APPVERSION) |
String |
|
1.2.3-unstable |
$(APP_VERSION_EXTENDED_STRING) |
String |
|
1.2.3-unstable+4 |
$(APP_VERSION_TWEAK_STRING) |
String |
|
1.2.3+4 |
Use in CMake
The following variable are available for usage in CMake files:
Variable |
Type |
Field(s) |
Example |
APPVERSION |
Numerical (hex) |
|
0x1020304 |
APP_VERSION_NUMBER |
Numerical (hex) |
|
0x10203 |
APP_VERSION_MAJOR |
Numerical |
|
1 |
APP_VERSION_MINOR |
Numerical |
|
2 |
APP_PATCHLEVEL |
Numerical |
|
3 |
APP_VERSION_TWEAK |
Numerical |
|
4 |
APP_VERSION_STRING |
String |
|
1.2.3-unstable |
APP_VERSION_EXTENDED_STRING |
String |
|
1.2.3-unstable+4 |
APP_VERSION_TWEAK_STRING |
String |
|
1.2.3+4 |
Use in MCUboot-supported applications
No additional configuration needs to be done to the target application so long as it is configured to support MCUboot and a signed image is generated, the version information will be automatically included in the image data.