/*      $NetBSD: rtld_start.S,v 1.11 2024/08/03 21:59:58 riastradh Exp $        */

/*
 * Copyright 1997 Michael L. Hitch <mhitch@montana.edu>
 * Portions copyright 2002 Charles M. Hannum <root@ihack.net>
 * All rights reserved.
 *
 * 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.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * 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.
 */

#include <mips/asm.h>

.globl _C_LABEL(_rtld_relocate_nonplt_self)
.globl _C_LABEL(_rtld)

#define PTR_SIZE        (1<<PTR_SCALESHIFT)

LEAF(rtld_start)
        .frame  sp, 4*PTR_SIZE, ra
        .mask   0x10090000,-PTR_SIZE
        .set    noreorder
        SETUP_GP
        PTR_SUBU sp, 4*PTR_SIZE         # adjust stack pointer
        SETUP_GP64(s4, rtld_start)
        SAVE_GP(0)
                                        # -> 1*PTR_SIZE(sp) for atexit
                                        # -> 2*PTR_SIZE(sp) for obj_main
        move    s0, a0                  # save stack pointer from a0
        move    s3, a3                  # save ps_strings pointer

        PTR_LA  a1, 1f
        bal     1f
         PTR_LA t0, _C_LABEL(_rtld_relocate_nonplt_self)
1:      PTR_SUBU a1, ra, a1             # relocbase
        move    s2, a1                  # save for _rtld
        PTR_LA  a0, _DYNAMIC
        PTR_ADDU t9, a1, t0
        jalr    t9                      # _rtld_relocate_nonplt_self(dynp, relocabase)
         PTR_ADDU a0, a1, a0            # &_DYNAMIC

        move    a1, s2                  # relocbase
        PTR_ADDU a0, sp, 2*PTR_SIZE     # sp
        jal     _C_LABEL(_rtld)         # v0 = _rtld(sp, relocbase)
         nop

        PTR_L   a1, 2*PTR_SIZE(sp)      # our atexit function
        PTR_L   a2, 3*PTR_SIZE(sp)      # obj_main entry
        PTR_ADDU sp, 4*PTR_SIZE         # readjust stack
        move    a0, s0                  # stack pointer
        move    t9, v0
        jr      t9                      # _start(sp, cleanup, obj);
         move   a3, s3                  # restore ps_strings

END(rtld_start)

#define XCALLFRAME_SIZ          (12*SZREG)
#define XCALLFRAME_RA           (10*SZREG)
#define XCALLFRAME_GP           (9*SZREG)
#define XCALLFRAME_S0           (8*SZREG)
#define XCALLFRAME_A3           (7*SZREG)
#define XCALLFRAME_A2           (6*SZREG)
#define XCALLFRAME_A1           (5*SZREG)
#define XCALLFRAME_A0           (4*SZREG)
#if defined(__mips_n32) || defined(__mips_n64)
#define XCALLFRAME_A7           (3*SZREG)
#define XCALLFRAME_A6           (2*SZREG)
#define XCALLFRAME_A5           (1*SZREG)
#define XCALLFRAME_A4           (0*SZREG)
#endif

        .globl  _rtld_bind_start
        .ent    _rtld_bind_start
_rtld_bind_start:
        .frame  sp, XCALLFRAME_SIZ, $15
        move    v1, gp                  # save old GP
#if defined(__mips_o32) || defined(__mips_o64)
        PTR_ADDU t9, 8                  # modify T9 to point at .cpload
#endif
        SETUP_GP
        PTR_SUBU sp, XCALLFRAME_SIZ     # save arguments and sp value in stack
        SETUP_GP64(XCALLFRAME_GP, _rtld_bind_start)
        SAVE_GP(XCALLFRAME_GP)
#if defined(__mips_n32) || defined(__mips_n64)
        REG_S   a4,  XCALLFRAME_A4(sp)
        REG_S   a5,  XCALLFRAME_A5(sp)
        REG_S   a6,  XCALLFRAME_A6(sp)
        REG_S   a7,  XCALLFRAME_A7(sp)
#endif
        REG_S   a0,  XCALLFRAME_A0(sp)
        REG_S   a1,  XCALLFRAME_A1(sp)
        REG_S   a2,  XCALLFRAME_A2(sp)
        REG_S   a3,  XCALLFRAME_A3(sp)
        REG_S   $15,  XCALLFRAME_RA(sp) # ra is in t7/t3
        REG_S   s0,  XCALLFRAME_S0(sp)
        move    s0, sp
        move    a0, t8                  # symbol index
        move    a1, $15                 # old RA
        move    a2, v1                  # old GP
        move    a3, ra                  # current RA
        jal     _C_LABEL(_rtld_bind)
         nop
        move    sp, s0
        REG_L   ra, XCALLFRAME_RA(sp)
        REG_L   s0, XCALLFRAME_S0(sp)
        REG_L   a0, XCALLFRAME_A0(sp)
        REG_L   a1, XCALLFRAME_A1(sp)
        REG_L   a2, XCALLFRAME_A2(sp)
        REG_L   a3, XCALLFRAME_A3(sp)
#if defined(__mips_n32) || defined(__mips_n64)
        REG_L   a4, XCALLFRAME_A4(sp)
        REG_L   a5, XCALLFRAME_A5(sp)
        REG_L   a6, XCALLFRAME_A6(sp)
        REG_L   a7, XCALLFRAME_A7(sp)
#endif
        RESTORE_GP64
        PTR_ADDU sp, XCALLFRAME_SIZ
        move    t9, v0
        jr      t9
         nop
END(_rtld_bind_start)