/*      $OpenBSD: srt0.s,v 1.8 2025/11/14 19:17:13 miod Exp $   */
/*      $NetBSD: srt0.s,v 1.1 2000/08/20 14:58:42 mrg Exp $     */

/*
 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
 * Copyright (C) 1995, 1996 TooLs GmbH.
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by TooLs GmbH.
 * 4. The name of TooLs GmbH may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``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 TOOLS GMBH 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/psl.h>
#include <machine/param.h>
#include <machine/frame.h>
#include <machine/asm.h>

/*
 * Globals
 */
        .globl  _esym
        .data
_esym:  .word   0                       /* end of symbol table */
        .globl  romp
        .align  8
        .register %g2,  #scratch
        .register %g3,  #scratch
romp:           .xword  0               /* openfirmware entry point */

/*
 * Startup entry
 */
        .text
        .globl  _start, kernel_text
        kernel_text = _start
_start:
        nop                     ! For some reason this is needed to fixup the text section
        
        /*
         * Step 1: Save rom entry pointer  -- NOTE this probably needs to change
         */
        
        mov     %o4, %g7        ! save prom vector pointer
        set     romp, %g1
        stx     %o4, [%g1]      ! It's initialized data, I hope

        /*
         * Start by creating a stack for ourselves.
         */
        /* 64-bit stack */
        btst    1, %sp
        set     CC64FSZ, %g1    ! Frame Size (negative)
        bnz     1f
         set    BIAS, %g2       ! Bias (negative)
        andn    %sp, 0x0f, %sp  ! 16 byte align, per ELF spec.
        add     %g1, %g2, %g1   ! Frame + Bias
1:
        sub     %sp, %g1, %g1
        save    %g1, %g0, %sp
        
!       mov     %i0, %i4                ! Apparently we get our CIF in i0
        
        /*
         * Set the psr into a known state:
         * Set supervisor mode, interrupt level >= 13, traps enabled
         */
        wrpr    %g0, 0, %pil    ! So I lied
        wrpr    %g0, PSTATE_PRIV+PSTATE_IE, %pstate

        clr     %g4             ! Point %g4 to start of data segment
                                ! only problem is that apparently the
                                ! start of the data segment is 0
        
        /*
         * XXXXXXXX Need to determine what params are passed
         */
        call    setup
         nop
        mov     %i1, %o1                
        call    main
         mov    %i2, %o0
        call    exit
         nop
        call    _rtt
         nop

/*
 * void syncicache(void *start, int size)
 *
 * I$ flush.  Really simple.  Just flush over the whole range.
 */
        .align  8
        .globl  syncicache
syncicache:
        dec     4, %o1
        flush   %o0
        brgz,a,pt       %o1, syncicache
         inc    4, %o0
        retl
         nop
        
/*
 * openfirmware(cell* param);
 *
 * OpenFirmware entry point 
 * 
 * If we're running in 32-bit mode we need to convert to a 64-bit stack
 * and 64-bit cells.  The cells we'll allocate off the stack for simplicity.
 */
        .align 8
        .globl  openfirmware
        .proc 1
        FTYPE(openfirmware)
openfirmware:
        andcc   %sp, 1, %g0
        bz,pt   %icc, 1f
         sethi  %hi(romp), %o1
        
        ldx     [%o1+%lo(romp)], %o4                    ! v9 stack, just load the addr and callit
        save    %sp, -CC64FSZ, %sp
        mov     %i0, %o0                                ! Copy over our parameter
        mov     %g1, %l1
        mov     %g2, %l2
        mov     %g3, %l3
        mov     %g4, %l4
        mov     %g5, %l5
        mov     %g6, %l6
        mov     %g7, %l7
        rdpr    %pstate, %l0
        jmpl    %i4, %o7
         wrpr   %g0, PSTATE_PROM|PSTATE_IE, %pstate
        wrpr    %l0, %g0, %pstate
        mov     %l1, %g1
        mov     %l2, %g2
        mov     %l3, %g3
        mov     %l4, %g4
        mov     %l5, %g5
        mov     %l6, %g6
        mov     %l7, %g7
        ret
         restore        %o0, %g0, %o0

1:                                              ! v8 -- need to screw with stack & params
        save    %sp, -CC64FSZ, %sp                      ! Get a new 64-bit stack frame
        add     %sp, -BIAS, %sp
        sethi   %hi(romp), %o1
        rdpr    %pstate, %l0
        ldx     [%o1+%lo(romp)], %o1                    ! Do the actual call
        srl     %sp, 0, %sp
        mov     %i0, %o0
        mov     %g1, %l1
        mov     %g2, %l2
        mov     %g3, %l3
        mov     %g4, %l4
        mov     %g5, %l5
        mov     %g6, %l6
        mov     %g7, %l7
        jmpl    %o1, %o7
         wrpr   %g0, PSTATE_PROM|PSTATE_IE, %pstate     ! Enable 64-bit addresses for the prom
        wrpr    %l0, 0, %pstate
        mov     %l1, %g1
        mov     %l2, %g2
        mov     %l3, %g3
        mov     %l4, %g4
        mov     %l5, %g5
        mov     %l6, %g6
        mov     %l7, %g7
        ret
         restore        %o0, %g0, %o0