Subversion Repositories openrisc_2011-10-31

/*

 * C startup code for the Fujitsu SPARClite demo board

 *

 * Copyright (c) 1995, 1996 Cygnus Support

 *

 * 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"

#ifdef TARGET_CPU_SPARC64

#define STACK_BIAS 2047

#define SAVE_SIZE -128

#else

#define SAVE_SIZE -64

#endif

.data

        .align  8

SYM(environ):                   ! this is the first address in the data section

        .long   0

SYM(argc):

        .long   0

        .text

        .align 8

        .globl SYM(start)

        .globl start

SYM(start):

start:

        /* see if the stack is already setup. if not, then default

         *  to using the value of %sp as set by the ROM monitor

         */

        sethi   %hi(__stack), %g1

        or      %g1,%lo(__stack),%g1

        cmp     %g0,%g1

        be      1f

        nop

#ifdef STACK_BIAS

        sub     %g1, STACK_BIAS, %g1

#endif

        mov     %g1, %sp                                ! set the stack pointer

        mov     0, %fp

1:

        /* zero the bss section */

        sethi %hi(__bss_start),%g2

        or    %g2,%lo(__bss_start),%g2          ! start of bss

        sethi %hi(_end),%g3

        or    %g3,%lo(_end),%g3                 ! end of bss

        mov   %g0,%g1                           ! so std has two zeros

zerobss:

        std    %g0,[%g2]

        add    %g2,8,%g2

        cmp    %g2,%g3

        bleu,a zerobss

        nop

/*

 * initialize target specific stuff. Only execute these

 * functions it they exist.

 */

init:

        sethi   %hi(SYM(hardware_init_hook)), %g1

        or      %g1,%lo(SYM(hardware_init_hook)),%g1

        cmp     %g0,%g1

        be      1f

        nop

        call    SYM(hardware_init_hook)

        nop

1:

        sethi   %hi(SYM(software_init_hook)), %g1

        or      %g1,%lo(SYM(software_init_hook)),%g1

        cmp     %g0,%g1

        be      2f

        nop

        call    SYM(software_init_hook)

        nop

2:

        set     SYM(__sigtramp), %o0

        call    SYM(__install_signal_handler)

        nop

        set     do_dtors,%o0

        call    SYM(atexit)

        nop

        call    do_ctors

        nop

        set     SYM(argc), %o0

        call    SYM(__getProgramArgs)

        nop

        mov     %o0, %o1

        set     SYM(argc), %o0

        ld      [%o0], %o0

        call SYM(main)

        nop

        /* call exit from the C library so atexit gets called, and the

         * C++ destructors get run. This calls our exit routine below

         * when it's done.

         */

        call    SYM(exit)

        nop

do_ctors:

        save    %sp,SAVE_SIZE,%sp

        set     __CTOR_LIST__,%l0

our_entry:

        ld      [%l0],%l1

        add     %l0,4,%l0

        tst     %l1

1:

        beq     2f

        nop

        ld      [%l0],%l2

        add     %l0,4,%l0

        call    %l2

        nop

        deccc   %l1

        b       1b

        nop

2:

        ret

        restore

do_dtors:

        save    %sp,SAVE_SIZE,%sp

        set     __DTOR_LIST__,%l0

        b       our_entry

        nop