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/*  rtems.s
 *
 *  This file contains the single entry point code for
 *  the PowerPC implementation of RTEMS.
 *
 *  Author:     Andrew Bray <andy@i-cubed.co.uk>
 *
 *  COPYRIGHT (c) 1995 by i-cubed ltd.
 *
 *  To anyone who acknowledges that this file is provided "AS IS"
 *  without any express or implied warranty:
 *      permission to use, copy, modify, and distribute this file
 *      for any purpose is hereby granted without fee, provided that
 *      the above copyright notice and this notice appears in all
 *      copies, and that the name of i-cubed limited not be used in
 *      advertising or publicity pertaining to distribution of the
 *      software without specific, written prior permission.
 *      i-cubed limited makes no representations about the suitability
 *      of this software for any purpose.
 *
 *  Derived from c/src/exec/cpu/no_cpu/rtems.c:
 *
 *  COPYRIGHT (c) 1989-1997.
 *  On-Line Applications Research Corporation (OAR).
 *  Copyright assigned to U.S. Government, 1994.
 *
 *  The license and distribution terms for this file may in
 *  the file LICENSE in this distribution or at
 *  http://www.OARcorp.com/rtems/license.html.
 *
 *  $Id: rtems.S,v 1.2 2001-09-27 11:59:29 chris Exp $
 */

#include <asm.h>

        BEGIN_CODE
/*
 *  RTEMS
 *
 *  This routine jumps to the directive indicated in r11.
 *  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.
 */

        ALIGN (4, 2)
        PUBLIC_PROC (RTEMS)
PROC (RTEMS):
#if (PPC_ABI == PPC_ABI_POWEROPEN)
        mflr    r0
        stw     r0, 8(r1)
        stwu    r1, -64(r1)

        /* Establish addressing */
        bl      base
base:
        mflr    r12
        addi    r12, r12, tabaddr - base

        lwz     r12, Entry_points-abase(r12)
        slwi    r11, r11, 2
        lwzx    r12, r12, r11

        stw     r2, 56(r1)
        lwz     r0, 0(r12)
        mtlr    r0
        lwz     r2, 4(r12)
        lwz     r11, 8(r12)
        blrl
        lwz     r2, 56(r1)
        addi    r1, r1, 64
        lwz     r0, 8(r1)
        mtlr    r0
#else
        mflr    r0
        stw     r0, 4(r1)
        stwu    r1, -16(r1)

        /* Establish addressing */
        bl      base
base:
        mflr    r12
        addi    r12, r12, tabaddr - base

        lwz     r12, Entry_points-abase(r12)
        slwi    r11, r11, 2
        lwzx    r11, r12, r11

        stw     r2, 8(r1)
#if (PPC_ABI != PPC_ABI_GCC27)
        stw     r13, 12(r1)
#endif
        mtlr    r11
        lwz     r11, irqinfo-abase(r12)
        lwz     r2, 0(r11)
#if (PPC_ABI != PPC_ABI_GCC27)
        lwz     r13, 4(r11)
#endif
        blrl
        lwz     r2, 8(r1)
#if (PPC_ABI != PPC_ABI_GCC27)
        lwz     r13, 12(r1)
#endif
        addi    r1, r1, 16
        lwz     r0, 4(r1)
        mtlr    r0
#endif
        blr


        /* Addressability stuff */
tabaddr:
abase:
        EXTERN_VAR (_Entry_points)
Entry_points:
        EXT_SYM_REF (_Entry_points)
#if (PPC_ABI != PPC_ABI_POWEROPEN)
        EXTERN_VAR (_CPU_IRQ_info)
irqinfo:
        EXT_SYM_REF (_CPU_IRQ_info)
#endif

#if (PPC_ABI == PPC_ABI_POWEROPEN)
        DESCRIPTOR (RTEMS)
#endif