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! crt1.s for sparc & sparcv9 (SunOS 5)

!   Copyright (C) 1992, 2009 Free Software Foundation, Inc.
!   Written By David Vinayak Henkel-Wallace, June 1992
! 
! This file is free software; you can redistribute it and/or modify it
! under the terms of the GNU General Public License as published by the
! Free Software Foundation; either version 3, or (at your option) any
! later version.
! 
! This file is distributed in the hope that it will be useful, but
! WITHOUT ANY WARRANTY; without even the implied warranty of
! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
! General Public License for more details.
! 
! Under Section 7 of GPL version 3, you are granted additional
! permissions described in the GCC Runtime Library Exception, version
! 3.1, as published by the Free Software Foundation.
!
! You should have received a copy of the GNU General Public License and
! a copy of the GCC Runtime Library Exception along with this program;
! see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
! <http://www.gnu.org/licenses/>.

! This file takes control of the process from the kernel, as specified
! in section 3 of the SVr4 ABI.
! This file is the first thing linked into any executable.

#ifdef __sparcv9
#define CPTRSIZE        8
#define CPTRSHIFT       3
#define STACK_BIAS      2047
#define ldn             ldx
#define stn             stx
#define setn(s, scratch, dst)   setx s, scratch, dst
#else
#define CPTRSIZE        4
#define CPTRSHIFT       2
#define STACK_BIAS      0
#define ldn             ld
#define stn             st
#define setn(s, scratch, dst)   set s, dst
#endif

        .section        ".text"
        .proc   022
        .global _start

_start:
        mov     0, %fp          ! Mark bottom frame pointer
        ldn     [%sp + (16 * CPTRSIZE) + STACK_BIAS], %l0       ! argc
        add     %sp, (17 * CPTRSIZE) + STACK_BIAS, %l1          ! argv

        ! Leave some room for a call.  Sun leaves 32 octets (to sit on
        ! a cache line?) so we do too.
#ifdef __sparcv9
        sub     %sp, 48, %sp
#else
        sub     %sp, 32, %sp
#endif

        ! %g1 may contain a function to be registered w/atexit
        orcc    %g0, %g1, %g0
#ifdef __sparcv9
        be      %xcc, .nope
#else
        be      .nope
#endif
        mov     %g1, %o0
        call    atexit
        nop   
.nope:
        ! Now make sure constructors and destructors are handled.
        setn(_fini, %o1, %o0)
        call    atexit, 1
        nop
        call    _init, 0
        nop

        ! We ignore the auxiliary vector; there is no defined way to
        ! access those data anyway.  Instead, go straight to main:
        mov     %l0, %o0        ! argc
        mov     %l1, %o1        ! argv
#ifdef GCRT1
        setn(___Argv, %o4, %o3)
        stn     %o1, [%o3]      ! *___Argv
#endif
        ! Skip argc words past argv, to env:
        sll     %l0, CPTRSHIFT, %o2
        add     %o2, CPTRSIZE, %o2
        add     %l1, %o2, %o2   ! env
        setn(_environ, %o4, %o3)
        stn     %o2, [%o3]      ! *_environ
        call    main, 4
        nop   
        call    exit, 0
        nop   
        call    _exit, 0
        nop   
        ! We should never get here.

        .type   _start,#function
        .size   _start,.-_start