RTEMS Available -- PowerPC/virtex feedback

gregory.menke at gsfc.nasa.gov gregory.menke at gsfc.nasa.gov
Fri Aug 10 12:52:45 UTC 2007

You'll have to apply -msoft-float to more than the RTEMS kernel, newlib
(being part of the toolchain) needed to be compiled with it as well.


Jiri Gaisler writes:
 > A similar problem exists with the SPARC bsps. The solution
 > we have made is to always compile the kernel with -msoft-float
 > to avoid the use of FPU registers. The FPU context handling
 > is written in assembler and always present in the kernel.
 > If a task uses the FPU, it will set the FPU enable bit in the
 > processor status register and the FPU context will be save
 > if necessary. On systems without FPU, the FPU task attribute is
 > never used, so no (unimplemented) FPU instructions are executed
 > to save the context. It is however necessary to compile all
 > code that is used by non-FPU tasks with -msoft-float. Sharing
 > of sub-routines between FPU and non-FPU tasks must therefore
 > be strictly controlled.

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