Version 3 (modified by JoelSherrill, on 06/13/07 at 19:30:06) (diff)

/* RTEMS API Changes */ Added more of the changes

4.8 Release Notes

Open Ideas are are: RTEMS48Ideas?

This page lists the changes and improvements that are planned and/or have been made to the RTEMS development source since the 4.7 release branch was made. As usual, there will be submissions that are not expected and incorporated as ready into the 4.7 release. In keeping with project history, the feature set of the 4.7 release series will be largely be driven by user submissions and requests.

Snapshots from this development effort are numbered 4.7.99.x with the latest being This snapshot may be found in or

Tool Improvements

  • Ralf Corsepius is continuing on his effort to improve the build infratructure and eventually support the CPU and BSP Kits in released version. This is both an RTEMS and a Tool Improvement as Ralf's goal is to be able to release CPU Kits in binary RPM form. In late May 2007, he made his first cpukits available for testing.
  • Thanks again to Ralf, it is possible to provide target specific versions of the development tools. This is important when GCC drops support for an old architecture or we are avoiding target specific bugs in a particular tool version. Nominally, most RTEMS targets will use the same tools and they have been upgraded to the following versions:
    • autoconf 2.61
    • automake 1.10
    • binutils 2.17
    • gcc 4.1.2 for C/C++ with newlib 1.15.0
    • gdb 6.6

RTEMS Improvements

  • Modified behavior when changing priority of a thread which is blocked on a priority based thread queue. Previously, the thread remained enqueued based upon its original priority. Now the thread is requeued to reflect its new priority. This work was sponsored by Saab Space.
  • Nanosecond time of day and time stamp granularity now supported.
    • CPU Usage statistics can be at nanosecond granularity
    • Rate Monotonic Period Usage statistics can be at nanosecond granularity
  • Rate Monotonic Period Usage statistics are now always maintained as part of the manager.
  • Optional Managers are more useful and now actually reduce the code size of your executable again.
  • The C Program Heap is now implemented directly in terms of the SuperCore? Heap Handler. This means that

the Region Manager is no longer a required manager.

  • The newlib reentrancy user extension is now statically installed. This means that the User Extension

Manager is no longer a required manager.

  • Much work has been done to split files which contained multiple functions into one function per file

in the SuperCore?, Classic API, and SAPI. This reduces code space.

  • Much work as been done to instantiate global data on a per manager and per handler basis

in the SuperCore?, Classic API, and SAPI. This reduces .data and .bss space.

  • Promotion of libmisc components to "first class citizens". This involves changing the name of routines to reflect RTEMS naming standards, adding documentation to the Users Guide and where appropriate integrating them more tightly with the RTEMS SuperCore? or API implementations. This impacts the CPU Usage, Stack Checker, and Rate Monotonic Usage support components.
  • Addition of new general object operations
    • object ID to name lookup service -- rtems_object_id_to_name()
    • XXX look up other one
  • Addition of rtems_iterate_over_all_threads() service that iterates over all threads and tasks in the system calling a user supplied function
  • Addition of new Ports
    • Altera NIOS II from Kolja Waschk.
    • Analog Devices Blackfin from Alain Schaefer .
  • Addition of new BSPs
    • arm/rtl21xx
    • TBD
  • Additional POSIX API support
    • Barriers added -- DOCUMENTATION pending
    • Spinlocks added -- DOCUMENTATION pending
    • RWLocks added -- DOCUMENTATION pending
  • Additional Classic API support
    • Barriers added
  • Significant updates to existing BSPs
    • TBD
  • Removal of obsoleted target CPUs and accompanying BSPs:
    • TBD
    • Removal of obsoleted BSPs:
    • arm/armulator
    • m68k/dmv152


  • Most uses of rtems_unsignedXX and rtems_signedXX types should now use C99 uintXX_t and intXX_t types.
  • Classic API Barrier Manager added
  • Addition of object ID to name lookup services
    • rtems_object_id_to_name
    • rtems_object_get_name
  • Rate Monotonic Manager now implicitly maintains statistics and adds the following services:
    • rtems_rate_monotonic_get_statistics,
    • rtems_rate_monotonic_reset_statistics,
    • rtems_rate_monotonic_reset_all_statistics,
    • rtems_rate_monotonic_report_statistics
  • Clock Improvements
    • clock_get_uptime
    • rtems_clock_set_nanoseconds_extension
  • Rate Monotonic Period Reporting Additions
    • TBD
  • CPU Usage Reporting Changes
    • TBD
  • Stack Checker Changes
    • TBD

TBD - list changes which will impact user programs

Changes Per Point Release

Release 4.8.0 Changes

When this happens, you will be the first to know. :)