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/*  entry.s

 *

 *  This file contains the entry point for the application.

 *  The name of this entry point is compiler dependent.

 *  It jumps to the BSP which is responsible for performing

 *  all initialization.

 *

 *  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.

 *

 *  $Id: start.S,v 1.2 2001-09-27 12:00:24 chris Exp $

 */

#include "asm.h"

#if (M68K_COLDFIRE_ARCH == 0) /* All ColdFire BSPs must provide their own start vector */

BEGIN_CODE

                                        | Default entry points for:

         PUBLIC (start)                 |   GNU

         PUBLIC (M68Kvec)               |   Vector Table

SYM (start):

SYM (M68Kvec):                          | standard location for vectors

        nop                             | for linkers with problem

                                        | location zero

        jmp      SYM (start_around)

     /*

      *  We can use the following space as our vector table

      *  if the CPU has a VBR or we can save vector table in it

      *  if the CPU does not.

      */

        .space   4088                   | to avoid initial intr stack

                                        |   from 135BUG on MVME13?

                                        |   and start code at 0x4000

SYM (vectors):

        .space   1016                   | reserve space for rest of vectors

#if ( M68K_HAS_SEPARATE_STACKS == 1 )

SYM (lowintstack):

        .space   4092                   | reserve for interrupt stack

SYM (hiintstack):

        .space   4                      | end of interrupt stack

#endif

        PUBLIC (start_around)

SYM (start_around):

        move.w  sr, SYM (initial_sr)

        oriw    #0x3700,sr              | SUPV MODE,INTERRUPTS OFF!!!

#if ( M68K_HAS_SEPARATE_STACKS == 1 )

        movec   isp,a0

        move.l  a0, SYM (initial_isp)

        movec   usp,a0

        move.l  a0, SYM (initial_usp)

        movec   msp,a0

        move.l  a0, SYM (initial_msp)

#else

        move.l  a7, SYM (initial_msp)

#endif

        |

        | zero out uninitialized data area

        |

zerobss:

        moveal  # SYM (_clear_end),a0     | find end of .bss

        moveal  # SYM (_clear_start),a1   | find beginning of .bss

        movel   #0,d0

loop:   movel   #0,a1@+                 | to zero out uninitialized

        cmpal   a0,a1

        jlt     loop                    | loop until _end reached

        movel   # SYM (_stack_init),d0  | d0 = stop of stack

        movw    #0x3700,sr              | SUPV MODE,INTERRUPTS OFF!!!

        movel   d0,a7                   | set master stack pointer

        movel   d0,a6                   | set base pointer

      /*

       *  RTEMS should maintain a separate interrupt stack on CPUs

       *  without one in hardware.  This is currently not supported

       *  on versions of the m68k without a HW intr stack.

       */

#if ( M68K_HAS_SEPARATE_STACKS == 1 )

        lea     SYM (hiintstack),a0   | a0 = high end of intr stack

        movec   a0,isp                | set interrupt stack

#endif

        pea     env                   | push environp

        pea     arg                   | push argv

        movel   #0,a7@-               | push argc

        jsr     SYM (boot_card)

        addl    #12,a7

#if ( M68K_HAS_SEPARATE_STACKS == 1 )

        move.l  SYM (initial_isp),a0

        movec   a0,isp

        move.l  SYM (initial_usp),a0

        movec   a0,usp

        move.l  SYM (initial_msp),a0

        movec   a0,msp

#else

        movea.l SYM (initial_msp),a7

#endif

        move.w  SYM (initial_sr),sr

        rts

END_CODE

BEGIN_DATA

        PUBLIC (environ)

        .align 2

SYM (environ):

        .long   env

        PUBLIC (start_frame)

SYM (start_frame):

        .space  4,0

END_DATA

BEGIN_BSS

env: .long  0

arg: .long  0

        PUBLIC (initial_isp)

SYM (initial_isp):

        .space  4

        PUBLIC (initial_msp)

SYM (initial_msp):

        .space  4

        PUBLIC (initial_usp)

SYM (initial_usp):

        .space  4

         PUBLIC (initial_sr)

SYM (initial_sr):

        .space  2

END_DATA

#endif

END