Subversion Repositories openrisc_2011-10-31

##==============================================================================
##
##      crt0-eval.S
##
##      MN10300 Series Evaluation Board C startup code
##
##==============================================================================
######COPYRIGHTBEGIN####
##
## Copyright (c) 1995, 1996, 1997, 1998 Cygnus Solutions
## 
## 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.
##
######COPYRIGHTEND####
        
##------------------------------------------------------------------------------
        
        .file   "crt0-eval.S"

##------------------------------------------------------------------------------
## Startup code
                        
        .equ    DRAM_TOP,0x48100000

        .text

        .globl  __start
__start:
        # Set up stack.  Leave 4K at top for use by Cygmon.

        mov     DRAM_TOP - 0x1000,a0
        sub     8,a0
        mov     a0,sp

        # Clear BSS

        mov     __bss_start,a0
        mov     _end,a1

        cmp     a0,a1
        beq     8f
        clr     d0
1:      
        movbu   d0,(a0)
        inc     a0
        cmp     a0,a1
        bne     1b      
8:      
        # Call constructors

        .extern ___main
        call    ___main,[],0

        # Call main
        clr     d0
        clr     d1
        mov     d0,(4,sp)

9:      
        or      0x0800,psw      # Enable interrupts
        
        .extern _main
        call    _main,[],0

        .extern __exit
        call    __exit,[],0

#       bra     9b              # Loop if we return

        
                        
##------------------------------------------------------------------------------                
## end of crt0-eval.S