/*      $OpenBSD: ldasm.S,v 1.3 2021/06/26 14:50:25 kettenis Exp $ */

/*
 * Copyright (c) 2016,2021 Dale Rahn <drahn@openbsd.org>
 *
 * 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 DL_DATA_SIZE    (16 * 8)        /* needs to be 8(16?) byte aligned */
#include <machine/asm.h>
#include <sys/syscall.h>

        .option norelax
        .section .boot.text,"ax",@progbits
        _ALIGN_TEXT
        .globl  _dl_start
        .type   _dl_start,@function
_dl_start:
        mv      a0, sp
        mv      fp, sp

        addi    sp, sp, -(8+8+DL_DATA_SIZE)     // dl_data size
        addi    s10, sp, 8                      // dl_data

        mv      a1, s10                         // dl_data

1:      auipc   a2, %pcrel_hi(_DYNAMIC)         /* &_DYNAMIC */
        addi    a2, a2, %pcrel_lo(1b)

        call    _dl_boot_bind

        ld      a0, (fp)                        // load argc
        addi    a1, fp, 0x0008                  // argv
        slli    a2, a0, 0x3
        add     a2, a1, a2
        addi    a2, a2, 0x0008                  // compute envp into a2

        // _dl_boot(argv, envp, loff, dl_data)
        mv      a0, a1                          // argv
        mv      a1, a2                          // envp
        ld      a2, (7*8)(s10)                  // loff from dl_data
        mv      a3, s10                         // dl_data

        call    _dl_boot

        mv      sp, fp                          // move stack back
        mv      fp, zero                        // clear frame back pointer

2:      auipc   a3, %pcrel_hi(_dl_dtors)                /* cleanup */
        addi    a3, a3, %pcrel_lo(2b)

        jr      a0
END(_dl_start)

ENTRY(_dl_bind_start)
        /*
         * t0 is the "link map"
         * t1 is the .got.plt offset
         */

        /* save parameter/result registers */
        addi    sp, sp, -(10*8)  /* should be aligned well enough */
        sd      ra, (9*8)(sp)
        sd      a0, (0*8)(sp)
        sd      a1, (1*8)(sp)
        sd      a2, (2*8)(sp)
        sd      a3, (3*8)(sp)
        sd      a4, (4*8)(sp)
        sd      a5, (5*8)(sp)
        sd      a6, (6*8)(sp)
        sd      a7, (7*8)(sp)

        /*
         * no need to save the FP registers as ld.so is compiled such that
         * it doesn't touch them
         */

        mv      a0, t0
        srli    a1, t1, 3
        jal     _dl_bind
        mv      t0, a0

        /* restore parameter/result registers */
        ld      a0, (0*8)(sp)
        ld      a1, (1*8)(sp)
        ld      a2, (2*8)(sp)
        ld      a3, (3*8)(sp)
        ld      a4, (4*8)(sp)
        ld      a5, (5*8)(sp)
        ld      a6, (6*8)(sp)
        ld      a7, (7*8)(sp)
        ld      ra, (9*8)(sp)
        addi    sp, sp, (10*8)

        jr      t0
END(_dl_bind_start)

ENTRY(_rtld_tlsdesc)
        RETGUARD_SETUP(_rtld_tlsdesc, x15)
        ld      a0, 8(a0)
        RETGUARD_CHECK(_rtld_tlsdesc, x15)
        ret
END(_rtld_tlsdesc)