srt0.S revision 1.1 
1/*	$NetBSD: srt0.S,v 1.1 1997/06/01 03:39:40 mrg Exp $	*/
2
3/*
4 * Copyright (c) 1994 Paul Kranenburg
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *	This product includes software developed by Paul Kranenburg.
18 * 4. The name of the author may not be used to endorse or promote products
19 *    derived from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33#include <machine/param.h>
34#include <machine/psl.h>
35
36#define	CCFSZ	96
37
38	.file	"str0.s"
39
40	.data
41	.global	_cputyp, _nbpg, _pgofset, _pgshift
42_cputyp:
43	.word	1
44_nbpg:
45	.word	1
46_pgofset:
47	.word	1
48_pgshift:
49	.word	1
50
51	.text
52	.globl	start
53
54start:
55	/*
56	 * Set up a stack.
57	 */
58	set	start, %o1
59	save	%o1, -CCFSZ, %sp
60
61	/*
62	 * Relocate.
63	 */
641:	call	2f
65	 nop
662:	add	%o7, (start-1b), %l0
67	set	start, %l1
68	set	_end, %o0
69	sub	%o0, %l1, %l2		! length
703:	ld	[%l0], %o0
71	add	%l0, 4, %l0
72	st	%o0, [%l1]
73	subcc	%l2, 4, %l2
74	bg	3b
75	 add	%l1, 4, %l1
76
77	set	4f, %g1
78	jmp	%g1
79	 nop
80
814:
82#ifdef notyet
83	/*
84	 * Enable traps
85	 */
86	wr	%g0, 0, %wim		! make sure we can set psr
87	nop; nop; nop
88	wr	%g0, PSR_S|PSR_PS|PSR_PIL, %psr	! set initial psr
89	nop; nop; nop
90	wr	%g0, 2, %wim		! set initial %wim (w1 invalid)
91
92	rd	%psr, %l0
93	wr	%l0, PSR_ET, %psr
94	nop; nop; nop
95#endif
96
97	/*
98	 * Clear BSS
99	 */
100	set     _edata, %o0             ! bzero(edata, end - edata)
101	set     _end, %o1
102	call    _bzero
103	 sub    %o1, %o0, %o1
104
105	/*
106	 * Enable interrupts, but only above level 11. This enables "L1-A",
107	 * but avoids spurious interrupt bites from most other devices.
108	 */
109	rd	%psr, %o0
110	andn	%o0, PSR_PIL, %o0
111	wr	%o0, 0xb00, %psr	! (11 << 8)
112	nop; nop; nop
113
114	/*
115	 * Set CPU type that we are running on.
116	 */
117	sethi	%hi(_cputyp), %o0
118	set	0x4000, %g7
119	cmp	%i0, %g7
120	beq	5f
121	 nop
122
123	/*
124	 * Save address of PROM vector (passed in %i0).
125	 */
126	sethi	%hi(_promvec), %o1
127	st	%i0, [%o1 + %lo(_promvec)]
128
129	mov	CPU_SUN4C, %g4
130	mov	SUN4CM_PGSHIFT, %g5
131	b,a	6f
132
1335:
134	mov	CPU_SUN4, %g4
135	mov	SUN4_PGSHIFT, %g5
136
1376:
138	st	%g4, [%o0 + %lo(_cputyp)]
139	sethi	%hi(_pgshift), %o0	! pgshift = log2(nbpg)
140	st	%g5, [%o0 + %lo(_pgshift)]
141
142	mov	1, %o0			! nbpg = 1 << pgshift
143	sll	%o0, %g5, %g5
144	sethi	%hi(_nbpg), %o0		! nbpg = bytes in a page
145	st	%g5, [%o0 + %lo(_nbpg)]
146
147	sub	%g5, 1, %g5
148	sethi	%hi(_pgofset), %o0	! page offset = bytes in a page - 1
149	st	%g5, [%o0 + %lo(_pgofset)]
150
151	call	_main
152	 mov	%i0, %o0
153
154	ret
155	 restore
156
157
158#ifdef TIGHT
159
160/*
161 * XXX - Space saving .div & .rem routines (small & non-negative numbres only)
162 */
163	.align	4
164	.global .div, .udiv
165! int n = 0; while (a >= b) { a -= b; n++; }; return n;
166.div:
167.udiv:
168	cmp	%o0, %o1
169	bl	2f
170	 mov	0, %o5
1711:
172	sub	%o0, %o1, %o0
173	cmp	%o0, %o1
174	bge	1b
175	 add	%o5, 1, %o5
1762:
177	retl
178	 mov	%o5, %o0
179
180	.align	4
181	.global .rem, .urem
182! while (a>=b) a -= b; return a;
183.rem:
184.urem:
185	cmp	%o0, %o1
186	bl	2f
187	 nop
188	sub	%o0, %o1, %o0
1891:
190	cmp	%o0, %o1
191	bge,a	1b
192	 sub	%o0, %o1, %o0
1932:
194	retl
195	 nop
196
197#endif /* TIGHT */
198