/*      $OpenBSD: ldasm.S,v 1.3 2020/07/16 21:18:09 kettenis Exp $ */

/*
 * Copyright (c) 1999 Dale Rahn
 *
 * 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 AUTHOR ``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 AUTHOR 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.
 *
 */

#define AUX_entry 9

#include <machine/asm.h>
#include <sys/syscall.h>

        .section .boot.text,"ax",@progbits
        .align  2
        .globl  _dl_start
        .type   _dl_start,@function
_dl_start:
        bl      1f
1:
        mflr    %r30
        addis   %r2, %r30, .TOC.-1b@ha
        addi    %r2, %r2, .TOC.-1b@l

        stdu    %r1, (-64 -((AUX_entry+3)*8))(%r1)      # Some space.

        # squirrel away the arguments for main
        mr      %r20, %r3       #argc
        mr      %r21, %r4       #argv
        mr      %r22, %r5       #envp
        mr      %r23, %r6       # ???
        nop

        addis   %r18, %r2,  _DYNAMIC@toc@ha
        addi    %r18, %r18, _DYNAMIC@toc@l

        ld      %r4,  -0x8000(%r2) # First entry of TOC is TOC base
        sub     %r4,  %r2, %r4  # determine load offset

        mr      %r17, %r4               # save for _dl_boot

        subi    %r3, %r21, 8    # Get stack pointer (arg0 for _dl_boot).
        addi    %r4, %r1, 32            # dl_data
        mr      %r5, %r18               # dynamicp

        bl      _dl_boot_bind

        mr      %r3, %r21               # argv
        mr      %r4, %r22               # envp
        mr      %r5, %r17               # loff
        addi    %r6, %r1, 32            # dl_data

        bl      _dl_boot

        mtctr   %r3             # put return value into ctr to execute

        # get back the squirreled away the arguments for main
        mr      %r3, %r20
        mr      %r4, %r21
        mr      %r5, %r22
        mr      %r6, %r23

        addis   %r7, %r2, _dl_dtors@toc@ha
        addi    %r7, %r7, _dl_dtors@toc@l

        mtlr    %r27
        ld      %r1, 0(%r1)             # Restore stack pointer.
        bctr                    # Go execute the 'real' program.
END(_dl_start)

ENTRY(_dl_bind_start)
        # r0 contains offset, do not overwrite 
        # r2 ld.so toc is loaded on entry to this function.
        mflr    %r12
        std     %r12,16(%r1)            # save  lr

        stdu    1,-104(%r1)

        std     %r3,32(%r1)             # save  r3-r10, C calling convention
        std     %r4,40(%r1)             # r13 - r31 are preserved by called code
        std     %r5,48(%r1)
        std     %r6,56(%r1)
        std     %r7,64(%r1)
        std     %r8,72(%r1)
        std     %r9,80(%r1)
        std     %r10,88(%r1)

        mr      %r3,%r11                # obj
        mr      %r4,%r0                 # relidx
        bl      _dl_bind                # _rtld_bind(obj, relidx)
        mtctr   %r3
        mr      %r12, %r3

        ld      %r3,32(%r1)
        ld      %r4,40(%r1)
        ld      %r5,48(%r1)
        ld      %r6,56(%r1)
        ld      %r7,64(%r1)
        ld      %r8,72(%r1)
        ld      %r9,80(%r1)
        ld      %r10,88(%r1)

        addi    %r1,%r1,104

        ld      %r0,16(%r1)             # restore lr
        mtlr    %r0

        bctr
END(_dl_bind_start)