Skip to content
Operating System Abstraction Layer
Branch: master
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.
doc Update to version 4.2.1a. Jun 29, 2017
src Update to version 4.2.1a. Jun 29, 2017
ut_assert Update to version 4.2.1a. Jun 29, 2017
.gitattributes Add attributes to correct language statistics. Jul 7, 2017
CMakeLists.txt Update to version 4.2.1a. Jun 29, 2017
LICENSE Setup standard files Feb 15, 2013
OSAL Version Description Document.docx Update to version 4.2.1a. Jun 29, 2017
OSAL Version Description Document.pdf Update to version 4.2.1a. Jun 29, 2017
OSAL Version Description Document.docx Update to version 4.2.1a. Jun 29, 2017
OSAL Version Description Document.pdf Update to version 4.2.1a. Jun 29, 2017
README.html Update to version 4.2.1a. Jun 29, 2017

Operating System Abstraction Layer Project

OSAL Logo by Michael Cudmore

The OS Abstraction Layer was originally devloped by the Flight Software Systems Branch at NASA Goddard Space Flight Center.

OS Abstraction Layer information:

This distribution contains:

  1. The OS Abstraction Layer Library
  2. Tests and example applications
  3. for the following targets:
    • Generic PPC running vxWorks 6.x ( Tested on vxWorks 6.4 )
    • Axiom m5235BCC Coldfire Evaluation board running the RTEMS 4.10 Operating System
    • A PC running Linux ( Tested on CentOS 5.x and 6.x 32 bit )
    • The sparc/sis simulator running RTEMS 4.10.2
  4. A directory structure and makefiles to manage it all.

Getting Started:

See the document doc/OSAL-Configuration-Guide.doc for complete details.

An easy way to get started is to use the Linux port and classic build:

  1. Set the OSAL_SRC environment variable to point to the OSAL source code.
    • Running will set the variable for you ($source ./
  2. Edit the build/osal-config.mak file and set the following options:
    • BSP - Set this to the board you are running on. For a PC running linux, use pc-linux
    • OS - Set this to the OS you are running. For a PC running linux, use posix.
    • OSAL_M32 - Uncomment/Add this build variable for building 32-bit images using "native" GCC on a 64-bit X86 Linux platform

Buiding on a PC running linux:

export OSAL_SRC = /home/acudmore/osal/src

In build/osal-config.mak:


Optional: OSAL_M32 = -m32 (Note: Usage of this flag may require an optional 'multilib' (or similar) 
package to be installed. Refer to your operating system and toolchain documentation for details, if 
adding the appropriate flag causes your builds to fail due to (for example) missing 32-bit or 
multilib related headers or libraries.) 

Optional: Some Linux systems may require an additional linker option in src/bsp/pc-linux/make/link-rules.mak:

LDFLAGS ?= $(OSAL_M32) -export-dynamic

If the symbol-api-test fails, then you need this option.

Now just type make config; make from the build directory and it should build the OSAL core files, tests, and sample applications for you. The binary for each application is in its own directory (i.e. build/examples/tasking-example/tasking-example.bin) You can switch to that directory and run it. You can also debug it using GDB.

NOTE: Running on linux may require root or adjusting the posix message queue maximum sizes.

The Embedded targets take a little more work to run, because they must be cross compiled and booted on the board. By copying a target, you should be able to come up with a new target.

If you would like just the OSAL itself, just look in src/os/inc for the include files and src/os/ for the OSAL implementation.

The API documentation is in the doc directory.

There are two sets of tests: build/tests and build/unit-tests. To build and the unit tests, perform the build steps above then make unit-tests in the build directory.

Instructions on how to use the newely supported cmake build system are provided in the OSAL Configuration Guide located in the doc directory.

Contact Information:

Alan Cudmore
NASA Goddard Space Flight Center
Code 582.0
Greenbelt, MD 20771

Copyright notice:

Copyright United States Government as represented by the Administrator of the National Aeronautics and Space Administration

License information:

This software is licensed under NASAs Open Source Agreement. The release of the software is conditional upon the recipients acceptance of the Open Source Agreement. Please see the file: NASA_Open_Source_Agreement_1_3-OS_AbstractionLayer.txt

You can’t perform that action at this time.