summaryrefslogtreecommitdiff
path: root/sys/arch/vax/stand/xxboot/start.s
blob: f39ecafab62b9dc84bdd35550bac928393340cf5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
/*	$OpenBSD: start.s,v 1.3 2000/11/25 21:33:08 hugh Exp $ */
/*	$NetBSD: start.s,v 1.2 1999/10/23 14:40:38 ragge Exp $ */
/*
 * Copyright (c) 1995 Ludd, University of Lule}, Sweden.
 * All rights reserved.
 *
 * This code is derived from software contributed to Ludd by
 * Bertram Barth.
 *
 * 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 at Ludd, University of 
 *      Lule}, Sweden and its contributors.
 * 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.
 */

 /* All bugs are subject to removal without further notice */
		

#define	_LOCORE

#include "sys/disklabel.h"

#include "../include/mtpr.h"
#include "../include/asm.h"		

_start:	.globl _start		# this is the symbolic name for the start
				# of code to be relocated. We can use this
				# to get the actual/real adress (pc-rel)
				# or to get the relocated address (abs).

.org	0x00			# uVAX booted from TK50 starts here
	brb	from_0x00	# continue behind dispatch-block

.org	0x02			# information used by uVAX-ROM
	.byte (LABELOFFSET + d_end_)/2 # offset in words to identification area 
	.byte	1		# this byte must be 1
	.word	0		# logical block number (word swapped) 
	.word	0		# of the secondary image

.org	0x08			#
	brb	from_0x08	# skip ...

.org	0x0A			# uVAX booted from disk starts here
	brb	from_0x0A	# skip ...

.org	0x0C			# 11/750  & 8200 starts here
	brw	cont_750


from_0x00:			# uVAX from TK50 
from_0x0A:			# uVAX from disk
	brw	start_uvax	# all(?) uVAXen continue there

from_0x08:			# What comes here???
	halt

.org	LABELOFFSET - 6
regmask: 	.word 0x0fff	# using a variable saves 3 bytes !!!
bootinfo:	.long 0x0	# another 3 bytes if within byte-offset

# the complete area reserved for label
# must be empty (i.e. filled with zeroes).
# disklabel(8) checks that before installing
# the bootblocks over existing label.

/*
 * Parameter block for uVAX boot.
 */
#define VOLINFO         0       /* 1=single-sided  81=double-sided volumes */
#define SISIZE          16      /* size in blocks of secondary image */
#define SILOAD          0       /* load offset (usually 0) from the default */
#define SIOFF           0x0A    /* byte offset into secondary image */

.org    LABELOFFSET + d_end_
	.byte	0x18		# must be 0x18 
	.byte	0x00		# must be 0x00 (MBZ) 
	.byte	0x00		# any value 
	.byte	0xFF - (0x18 + 0x00 + 0x00)	
		/* 4th byte holds 1s' complement of sum of previous 3 bytes */

	.byte	0x00		# must be 0x00 (MBZ) 
	.byte	VOLINFO
	.byte	0x00		# any value 
	.byte	0x00		# any value 

	.long	SISIZE		# size in blocks of secondary image 
	.long	SILOAD		# load offset (usually 0) 
	.long 	SIOFF		# byte offset into secondary image 
	.long	(SISIZE + SILOAD + SIOFF)	# sum of previous 3 

/*
 * After bootblock (LBN0) has been loaded into the first page 
 * of good memory by 11/750's ROM-code (transfer address
 * of bootblock-code is: base of good memory + 0x0C) registers
 * are initialized as:
 * 	R0:	type of boot-device
 *			0:	Massbus device
 *			1:	RK06/RK07
 *			2:	RL02
 *			17:	UDA50
 *			35:	TK50
 *			64:	TU58
 *	R1:	(UBA) address of UNIBUS I/O-page
 *		(MBA) address of boot device's adapter
 * 	R2:	(UBA) address of the boot device's CSR
 *		(MBA) controller number of boot device
 *	R6:	address of driver subroutine in ROM
 *
 * cont_750 reads in LBN1-15 for further execution.
 */
	.align 2
cont_750:
        movl    r0,r10
        clrl    r5
        clrl    r4
        movl    $_start,sp
1:      incl    r4
        movl    r4,r8
        addl2   $0x200,r5
        cmpl    $16,r4
        beql    2f
        pushl   r5
        jsb     (r6)
        blbs    r0,1b
2:      movl	r10, r0
	movl	r11, r5
	brw	start_all

	.org 0x300

start_uvax:
	mtpr	$0, $PR_MAPEN	# Turn off MM, please.
	movl    $_start, sp
	brb	start_all

/*
 * start_all: stack already at RELOC, we save registers, move ourself
 * to RELOC and loads boot.
 */
start_all:
	pushr	$0x1fff			# save all regs, used later.

	subl3	$_start, $_edata, r0	# get size of text+data (w/o bss)
	moval	_start, r1		# get actual base-address of code
	subl3	$_start, $_end, r2	# get complete size (incl. bss)
	movl	$_start, r3		# get relocated base-address of code
	movc5	r0, (r1), $0, r2, (r3)	# copy code to new location
	
	jsb 1f
1:	movl	$relocated, (sp)	# return-address on top of stack 
	rsb	 			# can be replaced with new address
relocated:				# now relocation is done !!!
	movl	sp, _bootregs
	calls	$0, _Xmain		# call Xmain (gcc workaround)which is 
	halt				# not intended to return ...

/*
 * hoppabort() is called when jumping to the newly loaded program.
 */
ENTRY(hoppabort, 0)
	movl    4(ap),r6
	movl    8(ap),r11
	movl    0xc(ap),r10
	movl	_memsz, r8
	mnegl	$1, ap		# Hack to figure out boot device.
	jmp	2(r6)
#	calls   $0,(r6)
	halt

# A bunch of functions unwanted in boot blocks.
ENTRY(getchar, 0)
	halt

ENTRY(putchar, 0)
	ret

ENTRY(panic, 0)
	halt