Subversion Repositories openrisc_2011-10-31

##==============================================================================

##

##      crt0.S

##

##      IQ2000 startup code

##

##==============================================================================

##

## Copyright (c) 2000, Cygnus Solutions, A Red Hat Company

##

## 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.

##

##------------------------------------------------------------------------------

        .file   "crt0.S"

##------------------------------------------------------------------------------

## Startup code

        .section .text

        .global _start

_start:

        lui %29,%hi(__stack)

        ori %29,%29,%lo(__stack)

        lui %24,%hi(_edata)     # get start of bss

        ori %24,%24,%lo(_edata)

        lui %25,%hi(_end)       # get end of bss

        ori %25,%25,%lo(_end)

        beq     %24,%25,.L0     # check if end and start are the same

                                # do nothing if no bss

.L1:

        sb %0,0(%24)            #  clear a byte and bump pointer

        addi %24,%24,1

        bne %24,%25,.L1

        nop

.L0:

        jal  _main              # call _main to run ctors/dtors

        nop

        xor %4,%4,%4

        jal main                # call main program

        xor %5,%5,%5

        jal exit                # all done, no need to return or

        or %4,%0,%2             # exit with main's return value

        .section .data

        .global __dso_handle

        .weak __dso_handle

__dso_handle:

        .long   0