/* $NetBSD: wdb00t.ahdi.S,v 1.3 2022/06/26 14:14:46 tsutsui Exp $ */
/*
* Copyright (c) 1995 Waldi Ravens
* 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 Waldi Ravens.
* 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 "xxboot.h"
.globl _start, main, fill
.text
_start: bras main
bra rds0
main: bclr #2,(_drvbits+3):w
clrl pun_ptr:w
movml %d3/%d5,%sp@-
movw #-1,%sp@-
movw #Kbshift,%sp@-
trap #BIOS
addql #4,%sp
btst #3,%d0 | Alternate?
bnes exit
movq #3,%d0
lea %pc@(p0_dsc),%a0
movb %d5,%d1 | NVRAM bootpref
bnes 0f
| The Hades bios does not provide a bootprev. In case
| of doubt, we fetch it ourselves.
movb #BOOTPREF,rtcrnr:w
movb rtcdat:w,%d1
bnes 0f
movq #-8,%d1 | bootpref = any
0: movb %a0@,%d2 | bootflags
btst #0,%d2
beqs 1f
andb %d1,%d2
bnes boot
1: lea %a0@(12),%a0
dbra %d0,0b
exit: movml %sp@+,%d3/%d5
tostst: clrw _bootdev:w
movl _sysbase:w,%a0
movl %a0@(24),%d0
swap %d0
cmpl #0x19870422,%d0 | old TOS?
bccs 0f | no
movw #0xe0,%d7
0: rts
boot: movl %a0@(4),%d6
movq #1,%d5
lea %pc@(end),%a4
bsrs rds0
tstw %d0
bnes exit
movl %a4,%a0
movw #0xff,%d0
movq #0,%d1
0: addw %a0@+,%d1
dbra %d0,0b
cmpw #0x1234,%d1
bnes exit
lea %pc@(rds0),%a3
lea %pc@(tostst),%a5
movml %sp@+,%d3/%d5
jmp %a4@ | start bootsector code
/*
* in: d4 (target) d5 (count), d6 (offset), a4 (buffer)
* out: d0 (<= 0)
* mod: d0, d1, d2, a0, a1, a5, a6
*/
rds0: lea %pc@(dpar),%a6
tstb %a6@
bnes 0f
movb %d4,%d0
andb #1,%d0
aslb #4,%d0
orb #0xa0,%d0
movb %d0,idesdh:l
movl %a4,%a0
movq #0,%d1
movb #0,idedor:l
movb #0xec,idecr:l | IDENTIFY DRIVE
bsrs wait
bnes err
movb %a4@(7),%a6@ | tracks/cylinder
movb %a4@(13),%a6@(1) | sectors/track
0: movl %d6,%d1
movq #0,%d0
movb %a6@(1),%d0
movq #0,%d2
movb %a6@,%d2
mulu %d0,%d2
divu %d2,%d1
movb %d1,idecl:l
lsrl #8,%d1
movb %d1,idech:l
lsrl #8,%d1
divu %d0,%d1
movb %d4,%d0
andb #1,%d0
aslb #4,%d0
orb %d0,%d1
orb #0xa0,%d1
movb %d1,idesdh:l
swap %d1
addqw #1,%d1
movb %d1,idesn:l
movl %a4,%a0
movb %d5,idesc:l
movw %d5,%d1
subqw #1,%d1
movb #0,idedor:l
movb #0x20,idecr:l
wait: movl #0x7d0,%d0
addl _hz_200:w,%d0
2: btst #5,gpip:w
beqs 3f
cmpl _hz_200:w,%d0
bhis 2b
err: movq #-1,%d0
rts
3: movb idesr:l,%d0
btst #0,%d0
bnes err
btst #3,%d0
beqs err
movq #63,%d0
lea idedr:l,%a1
4: movw %a1@,%a0@+
movw %a1@,%a0@+
movw %a1@,%a0@+
movw %a1@,%a0@+
dbra %d0,4b
dbra %d1,wait
movq #0,%d0
rts
fill: .space 52
dpar: .byte 0 | tracks/cylinder
.byte 0 | sectors/track
.ascii "NetBSD"
hd_siz: .long 0
p0_dsc: .long 0, 0, 0
p1_dsc: .long 0, 0, 0
p2_dsc: .long 0, 0, 0
p3_dsc: .long 0, 0, 0
bsl_st: .long 0
bsl_sz: .long 0
.word 0
end: