Subversion Repositories openrisc

/*  rtems.s

 *

 *  This file contains the single entry point code for

 *  the SPARC port of RTEMS.

 *

 *  COPYRIGHT (c) 1989-1999.

 *  On-Line Applications Research Corporation (OAR).

 *

 *  The license and distribution terms for this file may be

 *  found in the file LICENSE in this distribution or at

 *  http://www.OARcorp.com/rtems/license.html.

 *

 *  Ported to ERC32 implementation of the SPARC by On-Line Applications

 *  Research Corporation (OAR) under contract to the European Space

 *  Agency (ESA).

 *

 *  ERC32 modifications of respective RTEMS file: COPYRIGHT (c) 1995.

 *  European Space Agency.

 *

 *  $Id: rtems.S,v 1.2 2001-09-27 11:59:30 chris Exp $

 */

#include 

/*

 *  RTEMS

 *

 *  This routine jumps to the directive indicated in the

 *  CPU defined register.  This routine is used when RTEMS is

 *  linked by itself and placed in ROM.  This routine is the

 *  first address in the ROM space for RTEMS.  The user "calls"

 *  this address with the directive arguments in the normal place.

 *  This routine then jumps indirectly to the correct directive

 *  preserving the arguments.  The directive should not realize

 *  it has been "wrapped" in this way.  The table "_Entry_points"

 *  is used to look up the directive.

 *

 *  void RTEMS()

 */

        .align 4

        PUBLIC(RTEMS)

SYM(RTEMS):

        /*

         *  g2 was chosen because gcc uses it as a scratch register in

         *  similar code scenarios and the other locals, ins, and outs

         *  are off limits to this routine unless it does a "save" and

         *  copies its in registers to the outs which only works up until

         *  6 parameters.  Best to take the simple approach in this case.

         */

        sethi     SYM(_Entry_points), %g2

        or        %g2, %lo(SYM(_Entry_points)), %g2

        sll       %g1, 2,  %g1

        add       %g1, %g2, %g2

        jmp       %g2

        nop