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