Serious Bug All Targets -- Please Read

Joel Sherrill joel.sherrill at
Mon Mar 2 15:02:17 UTC 2009


There is a serious bug in all RTEMS 4.9 and newer
versions including CVS.  It does not impact 4.8 and

With RTEMS 4.9 , we converted from using an internal
RTEMS boolean type to the C99 standard bool.  This
changed the size of the variables from four bytes to
one byte. 

The CPU dependent code references two boolean variables
related to scheduling: _Context_Switch_necessary and
_ISR_Signals_to_thread_executing.  Anywhere these
are referenced in ASSEMBLY LANGUAGE is most likely

I desperately need help in reviewing and correcting
my first (uncompiled) attempt at fixing it.  I went
through the impacted assembly code and mechanically
tried to convert long/word operations into byte ones.
I may or may not have gotten it right on any target.

The first patch version is at:

Please help!!! I want to cut a 4.9.2 ASAP!!!

Joel Sherrill, Ph.D.             Director of Research & Development
joel.sherrill at        On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
   Support Available             (256) 722-9985

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