NetBSD/sys/arch/hp300/stand/srt0.s

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/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1982, 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* 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 the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* from: Utah $Hdr: srt0.c 1.18 92/12/21$
* from: @(#)srt0.c 8.1 (Berkeley) 6/10/93
*
* $Id: srt0.s,v 1.1 1994/01/26 02:39:02 brezak Exp $
*/
/*
* Startup code for standalone system
*/
.globl begin
.globl _end
.globl _edata
.globl _main
.globl _configure
.globl __rtt
.globl _bootdev,_howto,_lowram,_machineid
.globl _internalhpib
STACK = 0xfffff000 | below the ROM page
BOOTTYPE = 0xfffffdc0
LOWRAM = 0xfffffdce
SYSFLAG = 0xfffffed2 | system flags
MSUS = 0xfffffedc | MSUS (?) structure
VECTORS = 0xfffffee0 | beginning of jump vectors
NMIRESET = 0xffffff9c | reset vector
BUSERR = 0xfffffffc
MAXADDR = 0xfffff000
NBPG = 4096
MMUCMD = 0x005f400c | MMU command/status register
.data
_bootdev:
.long 0
_howto:
.long 0
_lowram:
.long 0
_machineid:
.long 0
.text
begin:
movl #STACK,sp
moveq #47,d0 | # of vectors - 1
movl #VECTORS+2,a0 | addr part of first vector
vecloop:
movl #trap,a0@ | make it direct to trap
addql #6,a0 | move to next vector addr
dbf d0,vecloop | go til done
movl #NMIRESET,a0 | NMI keyboard reset addr
movl #nmi,a0@ | catch in reset routine
/*
* Determine our CPU type and look for internal HP-IB
* (really only care about detecting 320 (no DIO-II) right now).
*/
lea _machineid,a0
movl #0x808,d0
movc d0,cacr | clear and disable on-chip cache(s)
movl #0x200,d0 | data freeze bit
movc d0,cacr | only exists on 68030
movc cacr,d0 | read it back
tstl d0 | zero?
jeq not68030 | yes, we have 68020/68040
movl #0x808,d0
movc d0,cacr | clear data freeze bit again
movl #0x80,MMUCMD | set magic cookie
movl MMUCMD,d0 | read it back
btst #7,d0 | cookie still on?
jeq not370 | no, 360 or 375
movl #4,a0@ | consider a 370 for now
movl #0,MMUCMD | clear magic cookie
movl MMUCMD,d0 | read it back
btst #7,d0 | still on?
jeq ihpibcheck | no, a 370
movl #5,a0@ | yes, must be a 340
jra ihpibcheck
not370:
movl #3,a0@ | type is at least a 360
movl #0,MMUCMD | clear magic cookie2
movl MMUCMD,d0 | read it back
btst #16,d0 | still on?
jeq ihpibcheck | no, a 360
movl #6,a0@ | yes, must be a 345/375/400
jra ihpibcheck
not68030:
bset #31,d0 | data cache enable bit
movc d0,cacr | only exists on 68040
movc cacr,d0 | read it back
tstl d0 | zero?
beq is68020 | yes, we have 68020
moveq #0,d0 | now turn it back off
movec d0,cacr | before we access any data
.long 0x4e7b0004 | movc d0,itt0
.long 0x4e7b0005 | movc d0,itt1
.long 0x4e7b0006 | movc d0,dtt0
.long 0x4e7b0007 | movc d0,dtt1
.word 0xf4d8 | cinva bc
movl MMUCMD,d0 | get MMU register
lsrl #8,d0 | get apparent ID
cmpb #6,d0 | id == 6?
jeq is33mhz | yes, we have a 433s
movl #7,a0@ | no, we have a 380/425t
jra ihpibcheck
is33mhz:
movl #8,a0@ | 433s (XXX 425s returns same ID, ugh!)
jra ihpibcheck
is68020:
movl #1,a0@ | consider a 330 for now
movl #1,MMUCMD | a 68020, write HP MMU location
movl MMUCMD,d0 | read it back
btst #0,d0 | zero?
jeq ihpibcheck | yes, a 330
movl #0,a0@ | no, consider a 320 for now
movl #0x80,MMUCMD | set magic cookie
movl MMUCMD,d0 | read it back
btst #7,d0 | cookie still on?
jeq ihpibcheck | no, just a 320
movl #2,a0@ | yes, a 350
ihpibcheck:
movl #0,MMUCMD | make sure MMU is off
btst #5,SYSFLAG | do we have an internal HP-IB?
jeq boottype | yes, continue
clrl _internalhpib | no, clear the internal address
/*
* If this is a reboot, extract howto/bootdev stored by kernel
*/
boottype:
cmpw #12,BOOTTYPE | is this a reboot (REQ_REBOOT)?
jne notreboot | no, skip
lea MAXADDR,a0 | find last page
movl a0@+,d7 | and extract howto, bootdev
movl a0@+,d6 | from where doboot() left them
jra boot1
/*
* At this point we do not know which logical device the MSUS select
* code refers to so we cannot construct bootdev. So we just punt
* and let configure() construct it.
*/
notreboot:
moveq #0,d6 | make sure bootdev is invalid
cmpw #18,BOOTTYPE | does the user want to interact?
jeq askme | yes, go to it
moveq #0,d7 | default to RB_AUTOBOOT
jra boot1
askme:
moveq #3,d7 | default to RB_SINGLE|RB_ASKNAME
boot1:
movl d6,_bootdev | save bootdev and howto
movl d7,_howto | globally so all can access
movl LOWRAM,d0 | read lowram value from bootrom
addl #NBPG,d0 | must preserve this for bootrom to reboot
andl #0xfffff000,d0 | round to next page
movl d0,_lowram | stash that value
start:
movl #_edata,a2 | start of BSS
movl #_end,a3 | end
clr:
clrb a2@+ | clear BSS
cmpl a2,a3 | done?
bne clr | no, keep going
jsr _configure | configure critical devices
jsr _main | lets go
__rtt:
movl #3,_howto | restarts get RB_SINGLE|RB_ASKNAME
jmp start
/*
* probe a location and see if it causes a bus error
*/
.globl _badaddr
_badaddr:
movl BUSERR,__bsave | save ROM bus error handler address
movl sp,__ssave | and current stack pointer
movl #catchbad,BUSERR| plug in our handler
movl sp@(4),a0 | address to probe
movw a0@,d1 | do it
movl __bsave,BUSERR | if we got here, it did not fault
clrl d0 | return that this was not a bad addr
rts
catchbad:
movl __bsave,BUSERR | got a bus error, so restore old handler
movl __ssave,sp | manually restore stack
moveq #1,d0 | indicate that we got a fault
rts | return to caller of badaddr()
__bsave:
.long 0
__ssave:
.long 0
.globl _trap
trap:
moveml #0xFFFF,sp@- | save registers
movl sp,sp@- | push pointer to frame
jsr _trap | call C routine to deal with it
tstl d0
jeq Lstop
addql #4,sp
moveml sp@+,#0x7FFF
addql #8,sp
rte
Lstop:
stop #0x2700 | stop cold
nmi:
movw #18,BOOTTYPE | mark as system switch
jsr _kbdnmi | clear the interrupt
jra begin | start over
#ifdef ROMPRF
.globl _romout
_romout:
movl sp@(4),d0 | line number
movl sp@(8),a0 | string
jsr 0x150 | do it
rts
#endif