cpu.h

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

 *
 *  These macros perform the following functions:
 *     + initialize a context area
 *     + restart the current thread
 *     + calculate the initial pointer into a FP context area
 *     + initialize an FP context area
 */

#define _CPU_Context_Initialize( _the_context, _stack_base, _size, \
                                 _isr, _entry_point, _is_fp ) \
   do { \
     unsigned32 _stack; \
     \
     (_the_context)->sr      = 0x3000 | ((_isr) << 8); \
     _stack                  = (unsigned32)(_stack_base) + (_size) - 4; \
     (_the_context)->a7_msp  = (void *)_stack; \
     *(void **)_stack        = (void *)(_entry_point); \
   } while ( 0 )

#define _CPU_Context_Restart_self( _the_context ) \
  { asm volatile( "movew %0,%%sr ; " \
                  "moval %1,%%a7 ; " \
                  "rts"  \
        : "=d" ((_the_context)->sr), "=d" ((_the_context)->a7_msp) \
        : "0" ((_the_context)->sr), "1" ((_the_context)->a7_msp) ); \
  }

/*
 *  Floating Point Context Area Support routines
 */

#if (CPU_SOFTWARE_FP == TRUE)

/*
 *  This software FP implementation is only for GCC.
 */

#define _CPU_Context_Fp_start( _base, _offset ) \
   ((void *) _Addresses_Add_offset( (_base), (_offset) ) )


#define _CPU_Context_Initialize_fp( _fp_area ) \
   { \
   Context_Control_fp *_fp; \
   _fp = *(Context_Control_fp **)_fp_area; \
   _fp->_exception_bits = 0; \
   _fp->_trap_enable_bits = 0; \
   _fp->_sticky_bits = 0; \
   _fp->_rounding_mode = 0;  /* ROUND_TO_NEAREST */ \
   _fp->_format = 0;         /* NIL */ \
   _fp->_last_operation = 0;  /* NOOP */ \
   _fp->_operand1.df = 0; \
   _fp->_operand2.df = 0; \
   }
#else
#define _CPU_Context_Fp_start( _base, _offset ) \
   ((void *) \
     _Addresses_Add_offset( \
        (_base), \
        (_offset) + CPU_CONTEXT_FP_SIZE - 4 \
     ) \
   )

#define _CPU_Context_Initialize_fp( _fp_area ) \
   { unsigned32 *_fp_context = (unsigned32 *)*(_fp_area); \
     \
     *(--(_fp_context)) = 0; \
     *(_fp_area) = (unsigned8 *)(_fp_context); \
   }
#endif

/* end of Context handler macros */

/*
 *  _CPU_Thread_Idle_body
 *
 *  This routine is the CPU dependent IDLE thread body.
 *
 *  NOTE:  It need only be provided if CPU_PROVIDES_IDLE_THREAD_BODY
 *         is TRUE.
 */

void _CPU_Thread_Idle_body( void );

/*
 *  Fatal Error manager macros
 *
 *  These macros perform the following functions:
 *    + disable interrupts and halt the CPU
 */

#if ( M68K_COLDFIRE_ARCH == 1 )
#define _CPU_Fatal_halt( _error ) \
  { asm volatile( "move.w %%sr,%%d0\n\t" \
		  "or.l %2,%%d0\n\t" \
		  "move.w %%d0,%%sr\n\t" \
		  "move.l %1,%%d0\n\t" \
		  "move.l #0xDEADBEEF,%%d1\n\t" \
                  "halt" \
		  : "=g" (_error) \
		  : "0" (_error), "d"(0x0700) \
		  : "d0", "d1" ); \
  }
#else
#define _CPU_Fatal_halt( _error ) \
  { asm volatile( "movl  %0,%%d0; " \
                  "orw   #0x0700,%%sr; " \
                  "stop  #0x2700" : "=d" ((_error)) : "0" ((_error)) ); \
  }
#endif

/* end of Fatal Error manager macros */

/*
 *  Bitfield handler macros
 *
 *  These macros perform the following functions:
 *     + scan for the highest numbered (MSB) set in a 16 bit bitfield
 *
 *  NOTE:
 *
 *    It appears that on the M68020 bitfield are always 32 bits wide
 *    when in a register.  This code forces the bitfield to be in
 *    memory (it really always is anyway). This allows us to
 *    have a real 16 bit wide bitfield which operates "correctly."
 */

#define CPU_USE_GENERIC_BITFIELD_CODE FALSE
#define CPU_USE_GENERIC_BITFIELD_DATA FALSE

#if ( M68K_HAS_BFFFO == 1 )

#define _CPU_Bitfield_Find_first_bit( _value, _output ) \
  asm volatile( "bfffo (%1),#0,#16,%0" : "=d" (_output) : "a" (&_value));
#else

/* duplicates BFFFO results for 16 bits (i.e., 15-(_priority) in
   _CPU_Priority_bits_index is not needed), handles the 0 case, and
   does not molest _value -- jsg */
#if ( M68K_COLDFIRE_ARCH == 1 )
#define _CPU_Bitfield_Find_first_bit( _value, _output ) \
  { \
    extern const unsigned char __BFFFOtable[256]; \
    register int dumby; \
    \
    asm volatile ( \
       "   clr.l   %1\n"         \
       "   move.w  %2,%1\n"      \
       "   lsr.l   #8,%1\n"      \
       "   beq.s   1f\n"         \
       "   move.b  (%3,%1),%0\n" \
       "   bra.s   0f\n"         \
       "1: move.w  %2,%1\n"      \
       "   move.b  (%3,%1),%0\n" \
       "   addq.l  #8,%0\n"      \
       "0: and.l   #0xff,%0\n"   \
       : "=&d" ((_output)), "=&d" ((dumby))    \
       : "d" ((_value)), "ao" ((__BFFFOtable)) \
       : "cc" ) ; \
  }
#elif ( M68K_HAS_EXTB_L == 1 )
#define _CPU_Bitfield_Find_first_bit( _value, _output ) \
  { \
    extern const unsigned char __BFFFOtable[256]; \
    register int dumby; \
    \
    asm volatile ( "   move.w  %2,%1\n"        \
       "   lsr.w   #8,%1\n"        \
       "   beq.s   1f\n"           \
       "   move.b  (%3,%1.w),%0\n" \
       "   extb.l  %0\n"           \
       "   bra.s   0f\n"           \
       "1: moveq.l #8,%0\n"        \
       "   add.b   (%3,%2.w),%0\n" \
       "0:\n"                      \
       : "=&d" ((_output)), "=&d" ((dumby)) \
       : "d" ((_value)), "ao" ((__BFFFOtable)) \
       : "cc" ) ; \
  }
#else
#define _CPU_Bitfield_Find_first_bit( _value, _output ) \
  { \
    extern const unsigned char __BFFFOtable[256]; \
    register int dumby; \
    \
    asm volatile ( "   move.w  %2,%1\n"        \
       "   lsr.w   #8,%1\n"        \
       "   beq.s   1f\n"           \
       "   move.b  (%3,%1.w),%0\n" \
       "   and.l   #0x000000ff,%0\n"\
       "   bra.s   0f\n"           \
       "1: moveq.l #8,%0\n"        \
       "   add.b   (%3,%2.w),%0\n" \
       "0:\n"                      \
       : "=&d" ((_output)), "=&d" ((dumby)) \
       : "d" ((_value)), "ao" ((__BFFFOtable)) \
       : "cc" ) ; \
  }
#endif

#endif

/* end of Bitfield handler macros */

/*
 *  Priority handler macros
 *
 *  These macros perform the following functions:
 *    + return a mask with the bit for this major/minor portion of
 *      of thread priority set.
 *    + translate the bit number returned by "Bitfield_find_first_bit"
 *      into an index into the thread ready chain bit maps
 */

#define _CPU_Priority_Mask( _bit_number ) \
  ( 0x8000 >> (_bit_number) )

#define _CPU_Priority_bits_index( _priority ) \
  (_priority)

/* end of Priority handler macros */

/* functions */

/*
 *  _CPU_Initialize
 *
 *  This routine performs CPU dependent initialization.
 */

void _CPU_Initialize(
  rtems_cpu_table  *cpu_table,
  void      (*thread_dispatch)
);

/*
 *  _CPU_ISR_install_raw_handler
 *
 *  This routine installs a "raw" interrupt handler directly into the 
 *  processor's vector table.
 */
 
void _CPU_ISR_install_raw_handler(
  unsigned32  vector,
  proc_ptr    new_handler,
  proc_ptr   *old_handler
);

/*
 *  _CPU_ISR_install_vector
 *
 *  This routine installs an interrupt vector.
 */

void _CPU_ISR_install_vector(
  unsigned32       vector,
  proc_ptr         new_handler,
  proc_ptr        *old_handler
);

/*
 *  _CPU_Install_interrupt_stack
 *
 *  This routine installs the hardware interrupt stack pointer.
 */

void _CPU_Install_interrupt_stack( void );

/*
 *  _CPU_Context_switch
 *
 *  This routine switches from the run context to the heir context.
 */

void _CPU_Context_switch(
  Context_Control  *run,
  Context_Control  *heir
);

/*
 *  _CPU_Context_save_fp
 *
 *  This routine saves the floating point context passed to it.
 */

void _CPU_Context_save_fp(
  void **fp_context_ptr
);

/*
 *  _CPU_Context_restore_fp
 *
 *  This routine restores the floating point context passed to it.
 */

void _CPU_Context_restore_fp(
  void **fp_context_ptr
);

#if (M68K_HAS_FPSP_PACKAGE == 1)
/*
 *  Hooks for the Floating Point Support Package (FPSP) provided by Motorola
 *
 *  NOTES:  
 *
 *  Motorola 68k family CPU's before the 68040 used a coprocessor
 *  (68881 or 68882) to handle floating point.  The 68040 has internal
 *  floating point support -- but *not* the complete support provided by
 *  the 68881 or 68882.  The leftover functions are taken care of by the
 *  M68040 Floating Point Support Package.  Quoting from the MC68040
 *  Microprocessors User's Manual, Section 9, Floating-Point Unit (MC68040):
 *
 *    "When used with the M68040FPSP, the MC68040 FPU is fully
 *    compliant with IEEE floating-point standards."
 *
 *  M68KFPSPInstallExceptionHandlers is in libcpu/m68k/MODEL/fpsp and
 *  is invoked early in the application code to insure that proper FP
 *  behavior is installed.  This is not left to the BSP to call, since
 *  this would force all applications using that BSP to use FPSP which
 *  is not necessarily desirable.
 *
 *  There is a similar package for the 68060 but RTEMS does not yet
 *  support the 68060.
 */

void M68KFPSPInstallExceptionHandlers (void);

SCORE_EXTERN int (*_FPSP_install_raw_handler)(
  unsigned32 vector,
  proc_ptr new_handler,
  proc_ptr *old_handler
);

#endif


#endif

#ifdef __cplusplus
}
#endif

#endif
/* end of include file */