* rtems/score/cpu.h: Add RTEMS_COMPILER_NO_RETURN_ATTRIBUTE to
_CPU_Context_restore() because it does not return. Telling GCC this
avoids generation of dead code.
PR 1635/cpukit
* rtems/score/cpu.h, rtems/score/types.h: Refactoring of priority
handling, to isolate the bitmap implementation of priorities in the
supercore so that priority management is a little more modular. This
change is in anticipation of scheduler implementations that can
select how they manage tracking priority levels / finding the highest
priority ready task. Note that most of the changes here are simple
renaming, to clarify the use of the bitmap-based priority management.
PR 1573/cpukit
* irq.c, rtems/score/cpu.h: Add a per cpu data structure which contains
the information required by RTEMS for each CPU core. This
encapsulates information such as thread executing, heir, idle and
dispatch needed.
* cpu.h: corrected the registers in Context_Control and
in CPU_Interrupt_frame to correspond to the saved frame in cpu_asm.S
Also switched on CPU_ISR_PASSES_FRAME_POINTER.
* cpu_asm.S: Moved the restore part of _CPU_Context_switch for
easier reading. Fixed _CPU_Context_restore, it now moves the
argument and branches to a label in _CPU_Context_switch. Removed
unnecessary saves of registers in context switch and irq handling.
Rewrote irq code to call the C helper. Added some documentation
* irq.c: New file derived from c4x and nios2.
