Subversion Repositories openrisc_me

/* Initial boot

 *

 * Copyright (c) 2006 CodeSourcery Inc

 *

 * The authors hereby grant permission to use, copy, modify, distribute,

 * and license this software and its documentation for any purpose, provided

 * that existing copyright notices are retained in all copies and that this

 * notice is included verbatim in any distributions. No written agreement,

 * license, or royalty fee is required for any of the authorized uses.

 * Modifications to this software may be copyrighted by their authors

 * and need not follow the licensing terms described here, provided that

 * the new terms are clearly indicated on the first page of each file where

 * they apply.

 */

        #include "asm.h"

        .text

        .extern __stack

        .extern __heap_end

        .weak __heap_end

        .extern __start1

        /* __reset should cause a HALT in a hosted executable and

           fall into __start for an unhosted executable.  The user is

           free to override this with their own declaration.  */

        .globl __reset

        .weak __reset

__reset:

#if HOSTED

        HALT

#endif

        .globl __start

__start:

        /* Initialize stack */

        move.l IMM(__stack), sp

        move.l IMM(0), fp

        move.l IMM(__heap_end), d1

#if HOSTED

        /* INIT_SIM syscall.  Allows changing sp & d1.  */

        move.l IMM(1),d0

        /* The semihosting sequence is 'nop; halt;sentinel' aligned to

           a 4 byte boundary.  The sentinel is an ill formed instruction

           (movec %sp,0).  The debugger will adjust the pc, so it is never

            executed.  */

        .balignw 4,0x4e71

        nop

        halt

        .long 0x4e7bf000

#endif

        move.l d1,sp@-

        move.l fp,sp@-  /* Dummy return address */

        jmp __start1