/*      $NetBSD: srt0.S,v 1.13 2026/03/13 21:13:45 andvar Exp $ */

/*-
 * Copyright (c) 1999 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Paul Kranenburg.
 *
 * 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.
 */

#define _LOCORE         /* XXX - fix Makefile */

#include <machine/param.h>
#include <machine/asm.h>
#include <machine/psl.h>

#define CCFSZ   96

        .file   "str0.s"

        .comm   _C_LABEL(romp), 4
        .comm   _C_LABEL(cputyp), 4
        .comm   _C_LABEL(nbpg), 4
        .comm   _C_LABEL(pgofset), 4
        .comm   _C_LABEL(pgshift), 4

        .text   
        .globl  start

start:
        /*
         * Set up a stack.
         */
        set     start, %o1
        save    %o1, -CCFSZ, %sp

        /*
         * Find which address we are at.
         */
1:      call    2f
         sethi  %hi(1b), %l0
2:      or      %l0, %lo(1b), %l0
        cmp     %l0, %o7        ! %o7 contains actual address of 1b
        beq     4f              ! already there, no need to relocate
         nop

        /*
         * Relocate.
         */
        add     %o7, (start-1b), %l0
        set     start, %l1
        set     _edata, %o0
        sub     %o0, %l1, %l2           ! length
3:      ld      [%l0], %o0
        add     %l0, 4, %l0
        st      %o0, [%l1]
        subcc   %l2, 4, %l2
        bg      3b
         add    %l1, 4, %l1

        /*
         * Jump to our relocated self.
         */
        set     4f, %g1
        jmp     %g1
         nop

4:
#ifdef notyet
        /*
         * Enable traps
         */
        wr      %g0, 0, %wim            ! make sure we can set psr
        nop; nop; nop
        wr      %g0, PSR_S|PSR_PS|PSR_PIL, %psr ! set initial psr
        nop; nop; nop
        wr      %g0, 2, %wim            ! set initial %wim (w1 invalid)

        rd      %psr, %l0
        wr      %l0, PSR_ET, %psr
        nop; nop; nop
#endif

        /*
         * Clear BSS
         */
        set     _edata, %o0             ! bzero(edata, end - edata)
1:      ! check if %o0 is well aligned
        andcc   %o0, 3, %o2
        bz      2f
         nop
        stb     %g0, [%o0]
        b       1b
         add    %o0, 1, %o0

2:      ! now we have %o0 4 byte aligned
        set     _end, %o1
        subcc   %o1, %o0, %o1
        bz      2f                      ! in case there is no BSS

        srl     %o1, 2, %o1             ! we do 4 byte writes now
1:
        st      %g0, [%o0]              ! while (n--)
        subcc   %o1, 1, %o1             !       *p = 0; etc..
        bnz     1b
         add    %o0, 4, %o0
2:

        /*
         * Enable interrupts, but only above level 11. This enables "L1-A",
         * but avoids spurious interrupt bites from most other devices.
         */
        rd      %psr, %o0
        andn    %o0, PSR_PIL, %o0
        wr      %o0, 0xb00, %psr        ! (11 << 8)
        nop; nop; nop

        /*
         * Set CPU type that we are running on.
         */
        sethi   %hi(_C_LABEL(cputyp)), %o0
        set     0x4000, %g7
        cmp     %i0, %g7
        beq     is_sun4
         nop

        mov     CPU_SUN4C, %g4
        mov     SUN4CM_PGSHIFT, %g5

        /*
         * OpenProm machines pass PROM vector in %o0 (%i0 after save)
         * OpenFirm machines pass OF entry in %o3 (%i3 after save)
         */
        cmp     %i0, 0
        be      is_openfirm
         nop

        ! save address of PROM vector
        sethi   %hi(_C_LABEL(romp)), %o1
        st      %i0, [%o1 + %lo(_C_LABEL(romp))]
        b,a     is_sun4cm

is_openfirm:
        ! only javastations have OFW, so we know it is a sun4m
        mov     CPU_SUN4M, %g4
        ! save address of OpenFirmware client interface handler
        sethi   %hi(_C_LABEL(romp)), %o1
        st      %i3, [%o1 + %lo(_C_LABEL(romp))]
        b,a     is_sun4cm

is_sun4:
        mov     CPU_SUN4, %g4
        mov     SUN4_PGSHIFT, %g5

is_sun4cm:
        st      %g4, [%o0 + %lo(_C_LABEL(cputyp))]
        sethi   %hi(_C_LABEL(pgshift)), %o0     ! pgshift = log2(nbpg)
        st      %g5, [%o0 + %lo(_C_LABEL(pgshift))]

        mov     1, %o0                          ! nbpg = 1 << pgshift
        sll     %o0, %g5, %g5
        sethi   %hi(_C_LABEL(nbpg)), %o0        ! nbpg = bytes in a page
        st      %g5, [%o0 + %lo(_C_LABEL(nbpg))]

        sub     %g5, 1, %g5
        sethi   %hi(_C_LABEL(pgofset)), %o0     ! page offset = nbpg - 1
        st      %g5, [%o0 + %lo(_C_LABEL(pgofset))]

        call    _C_LABEL(main)
         mov    %i0, %o0

        ret
         restore

/*
 * NO-OP place holder function.
 */
ENTRY(sparc_noop)
        retl
         nop

/*
 * Openfirmware entry point: openfirmware(void *args)
 */
ENTRY(openfirmware)
        sethi   %hi(_C_LABEL(romp)), %o1
        ld      [%o1 + %lo(_C_LABEL(romp))], %o2
        jmp     %o2
         nop

#ifdef TIGHT

/*
 * XXX - Space saving .div & .rem routines (small & non-negative numbers only)
 */
        .align  4
        .global .div, .udiv
! int n = 0; while (a >= b) { a -= b; n++; }; return n;
.div:
.udiv:
        cmp     %o0, %o1
        bl      2f
         mov    0, %o5
1:
        sub     %o0, %o1, %o0
        cmp     %o0, %o1
        bge     1b
         add    %o5, 1, %o5
2:
        retl
         mov    %o5, %o0

        .align  4
        .global .rem, .urem
! while (a>=b) a -= b; return a;
.rem:
.urem:
        cmp     %o0, %o1
        bl      2f
         nop
        sub     %o0, %o1, %o0
1:
        cmp     %o0, %o1
        bge,a   1b
         sub    %o0, %o1, %o0
2:
        retl
         nop

#endif /* TIGHT */