/* $NetBSD: srt0.s,v 1.3 2023/02/04 14:38:09 tsutsui Exp $ */
/*
* Copyright (c) 1994 Rolf Grossmann
* 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 Rolf Grossmann.
* 4. 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 <machine/asm.h>
/*
* Startup code for standalone system
*/
.text
ASENTRY_NOPROFILE(start)
|| clear bss (this should not hurt us i.e. cause an exception)
movel #_C_LABEL(edata),%a2 | start of BSS
movel #_C_LABEL(end),%a3 | end
Lclr:
clrb %a2@+ | clear BSS
cmpl %a2,%a3 | done?
bne Lclr | no, keep going
movl #0x0808,%d0
movc %d0,%cacr | clear and disable on-chip cache(s)
|| catch exceptions myself
movec %vbr,%a3
movel %a3,save_vbr | save register for restoration
lea vectbl,%a4
movel %a3@(4),%a4@(4) | copy mg, just for sure
movel %a3@(180),%a4@(180) | copy vector for trap #13
movel %a3@(124),%a4@(124) | copy vector for int 7
movec %a4,%vbr | use the new table
|| save mg as pi
movel %a3@(4),_C_LABEL(mg)
|| make sure we disallow interrupts
movew #0x2600,%sr
|| away we go
movel %sp@(4),%sp@- | copy the argument we got
jsr _C_LABEL(main) | call C
addql #4,%sp
ENTRY(_halt)
movel save_vbr,%a0
movec %a0,%vbr | restore prom vbr
hloop:
movel #halt,%d0
trap #13 | halt the system
bra hloop | and do not allow continuation
ASENTRY_NOPROFILE(astrap)
moveml %d0-%d7/%a0-%a7,%sp@- | save all registers
movel %sp,%sp@- | push pointer to registers
jsr _C_LABEL(trap) | call C to handle things (dump regs)
addql #4,%sp
tstl %d0
jeq Lstop
moveml %sp@+,%d0-%d7/%a0-%a7
rte
Lstop:
bra Lstop | stay here
