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## This file is part of eCos, the Embedded Configurable Operating System.

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##=============================================================================

/*****************************************************************************

hal_arch.S -- m68k architecture code

*****************************************************************************/

#include 

/*****************************************************************************

FUNC_START -- Function declaration macro

*****************************************************************************/

#define FUNC_START(name)                        \

        .text;                                  \

        .even;                                  \

        .globl name;                            \

name:

/*****************************************************************************

     The following routines assume the hal_jmp_buf structure is defined  as

shown below.

typedef struct {

    cyg_uint32 d2;

    cyg_uint32 d3;

    cyg_uint32 d4;

    cyg_uint32 d5;

    cyg_uint32 d6;

    cyg_uint32 d7;

    cyg_uint32 a2;

    cyg_uint32 a3;

    cyg_uint32 a4;

    cyg_uint32 a5;

    cyg_uint32 a6;

    cyg_uint32 sp;

    cyg_uint32 pc;

} hal_jmp_buf_t;

typedef cyg_uint32 hal_jmp_buf[sizeof(hal_jmp_buf_t) / sizeof(cyg_uint32)];

*****************************************************************************/

/*****************************************************************************

hal_m68k_setjmp -- Generic setjmp for the m68k architecture

externC int hal_m68k_setjmp(hal_jmp_buf env);

INPUT:

     0(%sp): return address

     4(%sp): env - address of a hal_jmp_buf structure

OUTPUT:

     d0, d1, a0, a1 are ours to abuse.

RETURN VALUE:

     This routine always returns zero in d0.l.

*****************************************************************************/

FUNC_START(hal_m68k_setjmp)

    lea.l   4(%sp),%a1                  /*   Get a pointer to the  position */

                                        /* of the stack pointer before this */

                                        /* call was  made.  IMPORTANT:  The */

                                        /* longjmp    routine    and    the */

                                        /* exception  handler  assume  that */

                                        /* saved stack  pointers  point  to */

                                        /* the location of the stack before */

                                        /* the routine/exception occurred.  */

    move.l  (%a1),%a0                   /*   Get a pointer to the buffer to */

                                        /* save our state into.             */

    movem.l %d2-%d7/%a2-%a6,(%a0)       /*   Write  all  of  the  preserved */

    lea     (11*4)(%a0),%a0             /* registers,  the  stack  pointer, */

    move.l  %a1,(%a0)+                  /* and the return address into  the */

    move.l  (%sp),(%a0)                 /* structure.                       */

    moveq.l #0,%d0                      /*   Load a zero  return value  and */

    rts                                 /* return.                          */

/*****************************************************************************

hal_m68k_longjmp -- Generic longjmp for the m68k architecture

externC void hal_m68k_longjmp(hal_jmp_buf env, int val);

INPUT:

     0(%sp): return address

     4(%sp): env - address of a hal_jmp_buf structure

     8(%sp): val - the non-zero value to return

OUTPUT:

     d0, d1, a0, a1 are ours to abuse.

RETURN VALUE:

     This routine always returns the value  from the val parameter in  d0.l

and to the location of the PC in the env structure.

*****************************************************************************/

FUNC_START(hal_m68k_longjmp)

    move.l  8(%sp),%d0                  /*   Load    the    return    value */

                                        /* parameter.                       */

    move.l  4(%sp),%a0                  /*   Get a pointer to the buffer to */

                                        /* read our state from.             */

    movem.l (%a0),%d2-%d7/%a2-%a6       /*   Load our preserved  registers, */

    lea     (11*4)(%a0),%a0             /* stack pointer and return address */

    move.l  (%a0)+,%d1                  /* from the structure.              */

    move.l  (%a0),%a1

    move.l  %d1,%sp                     /*   Set the stack pointer from the */

    jmp     (%a1)                       /* structure as  out current  stack */

                                        /* pointer and jump  to the  return */

                                        /* address from the structure.      */