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/*  cpu.h

 *

 *  This include file contains information pertaining to the Motorola

 *  m68xxx processor family.

 *

 *  COPYRIGHT (c) 1989-1999.

 *  On-Line Applications Research Corporation (OAR).

 *

 *  The license and distribution terms for this file may be

 *  found in the file LICENSE in this distribution or at

 *  http://www.OARcorp.com/rtems/license.html.

 *

 *  cpu.h,v 1.10 2002/04/03 14:13:01 joel Exp

 */

#ifndef __CPU_h

#define __CPU_h

#ifdef __cplusplus

extern "C" {

#endif

#include <rtems/score/m68k.h>              /* pick up machine definitions */

#ifndef ASM

#include <rtems/score/types.h>

#endif

/* conditional compilation parameters */

#define CPU_INLINE_ENABLE_DISPATCH       TRUE

#define CPU_UNROLL_ENQUEUE_PRIORITY      FALSE

/*

 *  Use the m68k's hardware interrupt stack support and have the

 *  interrupt manager allocate the memory for it.

 */

#if ( M68K_HAS_SEPARATE_STACKS == 1)

#define CPU_HAS_SOFTWARE_INTERRUPT_STACK 0

#define CPU_HAS_HARDWARE_INTERRUPT_STACK 1

#else

#define CPU_HAS_SOFTWARE_INTERRUPT_STACK 1

#define CPU_HAS_HARDWARE_INTERRUPT_STACK 0

#endif

#define CPU_ALLOCATE_INTERRUPT_STACK     1

/*

 *  Does the RTEMS invoke the user's ISR with the vector number and

 *  a pointer to the saved interrupt frame (1) or just the vector

 *  number (0)?

 */

#define CPU_ISR_PASSES_FRAME_POINTER 0

/*

 *  Some family members have no FP, some have an FPU such as the

 *  MC68881/MC68882 for the MC68020, others have it built in (MC68030, 040).

 *

 *  NOTE:  If on a CPU without hardware FP, then one can use software

 *         emulation.  The gcc software FP emulation code has data which

 *         must be contexted switched on a per task basis.

 */

#if ( M68K_HAS_FPU == 1 )

#define CPU_HARDWARE_FP     TRUE

#define CPU_SOFTWARE_FP     FALSE

#else

#define CPU_HARDWARE_FP     FALSE

#if defined(__GNUC__)

#define CPU_SOFTWARE_FP     TRUE

#else

#define CPU_SOFTWARE_FP     FALSE

#endif

#endif

/*

 *  All tasks are not by default floating point tasks on this CPU.

 *  The IDLE task does not have a floating point context on this CPU.

 *  It is safe to use the deferred floating point context switch

 *  algorithm on this CPU.

 */

#define CPU_ALL_TASKS_ARE_FP             FALSE

#define CPU_IDLE_TASK_IS_FP              FALSE

#define CPU_USE_DEFERRED_FP_SWITCH       TRUE

#define CPU_PROVIDES_IDLE_THREAD_BODY    FALSE

#define CPU_STACK_GROWS_UP               FALSE

#define CPU_STRUCTURE_ALIGNMENT

/*

 *  Define what is required to specify how the network to host conversion

 *  routines are handled.

 */

#define CPU_HAS_OWN_HOST_TO_NETWORK_ROUTINES     FALSE

#define CPU_BIG_ENDIAN                           TRUE

#define CPU_LITTLE_ENDIAN                        FALSE

#ifndef ASM

/* structures */

/*

 *  Basic integer context for the m68k family.

 */

typedef struct {

  unsigned32  sr;                /* (sr) status register */

  unsigned32  d2;                /* (d2) data register 2 */

  unsigned32  d3;                /* (d3) data register 3 */

  unsigned32  d4;                /* (d4) data register 4 */

  unsigned32  d5;                /* (d5) data register 5 */

  unsigned32  d6;                /* (d6) data register 6 */

  unsigned32  d7;                /* (d7) data register 7 */

  void       *a2;                /* (a2) address register 2 */

  void       *a3;                /* (a3) address register 3 */

  void       *a4;                /* (a4) address register 4 */

  void       *a5;                /* (a5) address register 5 */

  void       *a6;                /* (a6) address register 6 */

  void       *a7_msp;            /* (a7) master stack pointer */

}   Context_Control;

/*

 *  Floating point context ares

 */

#if (CPU_SOFTWARE_FP == TRUE)

/*

 *  This is the same as gcc's view of the software FP condition code

 *  register _fpCCR.  The implementation of the emulation code is

 *  in the gcc-VERSION/config/m68k directory.  This structure is

 *  correct as of gcc 2.7.2.2.

 */

typedef struct {

  unsigned16   _exception_bits;

  unsigned16   _trap_enable_bits;

  unsigned16   _sticky_bits;

  unsigned16   _rounding_mode;

  unsigned16   _format;

  unsigned16   _last_operation;

  union {

    float sf;

    double df;

  } _operand1;

  union {

    float sf;

    double df;

  } _operand2;

} Context_Control_fp;

#else 

/*

 *  FP context save area for the M68881/M68882 numeric coprocessors.

 */

typedef struct {

  unsigned8   fp_save_area[332];    /*   216 bytes for FSAVE/FRESTORE    */

                                    /*    96 bytes for FMOVEM FP0-7      */

                                    /*    12 bytes for FMOVEM CREGS      */

                                    /*     4 bytes for non-null flag     */

} Context_Control_fp;

#endif

/*

 *  The following structures define the set of information saved

 *  on the current stack by RTEMS upon receipt of each exc/interrupt.

 *  These are not used by m68k handlers.

 *  The exception frame is for rdbg.

 */

typedef struct {

  unsigned32 vecnum; /* vector number */

} CPU_Interrupt_frame;

typedef struct {

  unsigned32 vecnum; /* vector number */

  unsigned32 sr; /* status register */

  unsigned32 pc; /* program counter */

  unsigned32 d0, d1, d2, d3, d4, d5, d6, d7;

  unsigned32 a0, a1, a2, a3, a4, a5, a6, a7;

} CPU_Exception_frame;

/*

 *  The following table contains the information required to configure

 *  the m68k specific parameters.

 */

typedef struct {

  void       (*pretasking_hook)( void );

  void       (*predriver_hook)( void );

  void       (*postdriver_hook)( void );

  void       (*idle_task)( void );

  boolean      do_zero_of_workspace;

  unsigned32   idle_task_stack_size;

  unsigned32   interrupt_stack_size;

  unsigned32   extra_mpci_receive_server_stack;

  void *     (*stack_allocate_hook)( unsigned32 );

  void       (*stack_free_hook)( void* );

  /* end of fields required on all CPUs */

  m68k_isr    *interrupt_vector_table;

}   rtems_cpu_table;

/*

 *  Macros to access required entires in the CPU Table are in

 *  the file rtems/system.h.

 */

/*

 *  Macros to access M68K specific additions to the CPU Table

 */

#define rtems_cpu_configuration_get_interrupt_vector_table() \

   (_CPU_Table.interrupt_vector_table)

/* variables */

SCORE_EXTERN void                   *_CPU_Interrupt_stack_low;

SCORE_EXTERN void                   *_CPU_Interrupt_stack_high;

extern char                         _VBR[];

#if ( M68K_HAS_VBR == 0 )

/*

 * Table of ISR handler entries that resides in RAM. The FORMAT/ID is

 * pushed onto the stack. This is not is the same order as VBR processors.

 * The ISR handler takes the format and uses it for dispatching the user

 * handler.

 *

 * FIXME : should be moved to below CPU_INTERRUPT_NUMBER_OF_VECTORS

 *

 */

typedef struct {

  unsigned16 move_a7;            /* move #FORMAT_ID,%a7@- */

  unsigned16 format_id;

  unsigned16 jmp;                /* jmp  _ISR_Handlers */

  unsigned32 isr_handler;

} _CPU_ISR_handler_entry;

#define M68K_MOVE_A7 0x3F3C

#define M68K_JMP     0x4EF9

      /* points to jsr-exception-table in targets wo/ VBR register */

SCORE_EXTERN _CPU_ISR_handler_entry _CPU_ISR_jump_table[256];

#endif /* M68K_HAS_VBR */

#endif /* ASM */

/* constants */

/*

 *  This defines the number of levels and the mask used to pick those

 *  bits out of a thread mode.

 */

#define CPU_MODES_INTERRUPT_LEVEL  0x00000007 /* interrupt level in mode */

#define CPU_MODES_INTERRUPT_MASK   0x00000007 /* interrupt level in mode */

/*

 *  context size area for floating point

 */

#define CPU_CONTEXT_FP_SIZE sizeof( Context_Control_fp )

/*

 *  extra stack required by the MPCI receive server thread

 */

#define CPU_MPCI_RECEIVE_SERVER_EXTRA_STACK 1024

/*

 *  m68k family supports 256 distinct vectors.

 */

#define CPU_INTERRUPT_NUMBER_OF_VECTORS      256

#define CPU_INTERRUPT_MAXIMUM_VECTOR_NUMBER  (CPU_INTERRUPT_NUMBER_OF_VECTORS - 1)

/*

 *  This is defined if the port has a special way to report the ISR nesting

 *  level.  Most ports maintain the variable _ISR_Nest_level.

 */

#define CPU_PROVIDES_ISR_IS_IN_PROGRESS FALSE

/*

 *  Minimum size of a thread's stack.

 */

#define CPU_STACK_MINIMUM_SIZE           4096

/*

 *  m68k is pretty tolerant of alignment.  Just put things on 4 byte boundaries.

 */

#define CPU_ALIGNMENT                    4

#define CPU_HEAP_ALIGNMENT               CPU_ALIGNMENT

#define CPU_PARTITION_ALIGNMENT          CPU_ALIGNMENT

/*

 *  On m68k thread stacks require no further alignment after allocation

 *  from the Workspace.

 */

#define CPU_STACK_ALIGNMENT        0

#ifndef ASM

/* macros */

/*

 *  ISR handler macros

 *

 *  These macros perform the following functions:

 *     + initialize the RTEMS vector table

 *     + disable all maskable CPU interrupts

 *     + restore previous interrupt level (enable)

 *     + temporarily restore interrupts (flash)

 *     + set a particular level

 */

#define _CPU_Initialize_vectors()

#define _CPU_ISR_Disable( _level ) \

  m68k_disable_interrupts( _level )

#define _CPU_ISR_Enable( _level ) \

  m68k_enable_interrupts( _level )

#define _CPU_ISR_Flash( _level ) \

  m68k_flash_interrupts( _level )

#define _CPU_ISR_Set_level( _newlevel ) \

   m68k_set_interrupt_level( _newlevel )

unsigned32 _CPU_ISR_Get_level( void );

/* end of ISR handler macros */

/*

 *  Context handler macros

 *

 *  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 */

/*

 *  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 */