/*      $NetBSD: rtld_start.S,v 1.1 2014/09/03 19:34:26 matt Exp $      */

/*-
 * Copyright (c) 2014 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Matt Thomas of 3am Software Foundry.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <machine/asm.h>

        .globl  _rtld_start
        .globl  _rtld

#define CF_LEN          (3*__SIZEOF_POINTER__)
#define CF_OBJ          (2*__SIZEOF_POINTER__)
#define CF_CLEANUP      (1*__SIZEOF_POINTER__)

        /*
         * void ___start(void (*cleanup)(void), const Obj_Entry *obj,
         *    struct ps_strings *ps_strings);
         */
ENTRY_NP(_rtld_start)
        l.sw    CF_LEN(r1), r1          # reserve some stack space
#if 0
        l.ori   r26, r3, 0              # obj           (should be 0)
        l.ori   r28, r4, 0              # cleanup       (should be 0)
#endif
        l.ori   r30, r5, 0              # ps_strings
        l.addi  r1, r1, -CF_LEN

        PIC_GOTSETUP(r16)

        l.movhi r3, gotoffhi(_DYNAMIC)  # get _DYNAMIC gotoff address
        l.ori   r3, r3, gotofflo(_DYNAMIC)

        l.lwz   r7, 0(r16)              # get base-relative &_DYNAMIC
        l.add   r3, r3, r16             # r3 = _DYNAMIC actual address
        l.sub   r24, r3, r7             # r24 = relocbase
        l.ori   r4, r24, 0              # r4 = relocbase
        l.jal   _C_LABEL(_rtld_relocate_nonplt_self)
        l.nop

        l.addi  r3, r1, CF_CLEANUP
        l.ori   r4, r24, 0              # r4 = relocbase
        l.jal   _C_LABEL(_rtld)         # _start = _rtld(sp, relocbase)
        l.nop

        l.lwz   r3, CF_OBJ(r1)          # obj
        l.lwz   r4, CF_CLEANUP(r1)      # cleanup
        l.ori   r5, r30, 0              # ps_strings

        l.addi  r1, r1, CF_LEN          # pop stack
        l.jalr  r11                     # _start(obj, cleanup, ps_strings)

        l.ori   r13, r0, 1              # _exit()
        l.sys   0

END(_rtld_start)

        .globl  _rtld_bind

/*
 * r11 = rela offset
 * r12 = GOT[1] (&obj)
 * r15 = GOT[2] (&_rtld_bind_start)
 */
ENTRY_NP(_rtld_bind_start)

        l.sw    -4(r1), r9              # save lr
        l.sw    -8(r1), r8              # save arg5
        l.sw    -12(r1), r7             # save arg4
        l.sw    -16(r1), r6             # save arg3
        l.sw    -20(r1), r5             # save arg2
        l.sw    -24(r1), r4             # save arg1
        l.sw    -28(r1), r3             # save arg0
        l.sw    -32(r1), r1             # establish stack frame
        l.addi  r1, r1, -32

        l.ori   r3, r12, 0              # obj
        l.ori   r4, r11, 0              # reloff
        l.jal   _C_LABEL(_rtld_bind)    # _rtld_bind(obj, reloff)
        l.nop

        l.addi  r1, r1, 32              # pop stack frame
        l.lwz   r3, -28(r1)             # restore arg0
        l.lwz   r4, -24(r1)             # restore arg1
        l.lwz   r5, -20(r1)             # restore arg2
        l.lwz   r6, -16(r1)             # restore arg3
        l.lwz   r7, -12(r1)             # restore arg4
        l.lwz   r8, -8(r1)              # restore arg5
        l.lwz   r9, -4(r1)              # restore lr

        l.jr    r11                     # jump to routine
        l.nop
END(_rtld_bind_start)