xref: /netbsd-src/sys/arch/evbppc/explora/explora_start.S (revision d710132b4b8ce7f7cccaaf660cb16aa16b4077a0)
1/*	$NetBSD: explora_start.S,v 1.1 2003/03/11 10:57:56 hannken Exp $	*/
2
3/*-
4 * Copyright (c) 2003 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Juergen Hannken-Illjes.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *      This product includes software developed by the NetBSD
21 *      Foundation, Inc. and its contributors.
22 * 4. Neither the name of The NetBSD Foundation nor the names of its
23 *    contributors may be used to endorse or promote products derived
24 *    from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39/*
40 * Initial state:
41 *
42 * iccr = 0x00008001 0x80000000-0x87ffffff 0xf80000000-0xffffffff
43 * dccr = 0x00008001 0x80000000-0x87ffffff 0xf80000000-0xffffffff
44 * dcwr = 0x00000000
45 * msr  = 0x00001000 ME=machine check enable
46 *
47 */
48
49#include "assym.h"
50
51#include <machine/param.h>
52#include <machine/psl.h>
53#include <machine/trap.h>
54#include <machine/asm.h>
55
56#include <powerpc/spr.h>
57#include <powerpc/ibm4xx/dcr403cgx.h>
58#include <powerpc/ibm4xx/pmap.h>
59
60#include "opt_ddb.h"
61#include "opt_ppcparam.h"
62
63GLOBAL(proc0paddr)
64	.long	0			/* proc0 p_addr */
65
66GLOBAL(intrnames)
67	.asciz	"irq0", "irq1", "irq2", "irq3"
68	.asciz	"irq4", "irq5", "irq6", "irq7"
69	.asciz	"irq8", "irq9", "irq10", "irq11"
70	.asciz	"irq12", "irq13", "irq14", "irq15"
71	.asciz	"irq16", "irq17", "irq18", "softnet"
72	.asciz	"softclock", "softserial", "clock", "statclock"
73	.asciz	"irq24", "irq25", "irq26", "irq27"
74	.asciz	"irq28", "irq29", "irq30", "irq31"
75GLOBAL(eintrnames)
76	.align	4
77GLOBAL(intrcnt)
78	.long	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
79	.long	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
80GLOBAL(eintrcnt)
81
82/*
83 * Initially the dram starts at 0x01000000. This is way too high.
84 * We relocate dram to 0x00000000. We use the video ram at 0xf0000000
85 * as a temporary staging area.
86 */
87
88#define STAGE1_BASE	0xf0000000
89
90	.text
91	.globl	__start
92__start:
93	b	1f
94	nop
95	nop
96	.long	0
97	.ascii	"XncdPPC\0"
98	.long	0
99	.long	0
100
1011:
102	/* Disable exceptions, caches, invalidate all TLB's. */
103
104	li	0,0
105	mtmsr	0
106	mttcr	0
107	mtdccr	0
108	mticcr	0
109	sync
110	isync
111
112/* Clear caches and invalidate tlbs */
113	li	7,256
114	mtctr	7
115	li	6,0
1161:
117	dccci	0,6
118	addi	6,6,16
119	bdnz	1b
120
121	li	7,512
122	mtctr	7
123	li	6,0
1241:
125	iccci	0,6
126	addi	6,6,16
127	bdnz	1b
128
129	tlbia
130	sync
131	isync
132
133/* Get current address -- NOT the same as . */
134
135	bl	_next
136_next:
137	mflr	3
138	subi	3,3,_next-__start
139	lis	4,STAGE1_BASE@h
140	ori	4,4,STAGE1_BASE@l
141	li	5,stage1size
142
1431:
144	lbz	1,0(3)
145	mr	0,5
146	cmpwi	0,0
147	stb	1,0(4)
148	addi	3,3,1
149	addi	4,4,1
150	addi	5,5,-1
151	bgt	1b
152
153/* Jump into the staging area so we can remap the dram. */
154
155	lis	0,stage1reloc@h
156	ori	0,0,stage1reloc@l
157	mtlr	0
158	blr
159
160stage1reloc = .-__start+STAGE1_BASE
161
162/* Remap the dram from 0x01000000 to 0x00000000. */
163
164#define REMAP(r, tmp1, tmp2) \
165	mfbr##r	tmp1 ; \
166	lis	tmp2,0xff ; \
167	ori	tmp2,tmp2,0xffff ; \
168	cmplw	tmp1,tmp2 ; \
169	ble	1f ; \
170	addis	tmp1,tmp1,0xf000 ; \
171	mtbr##r	tmp1 ; \
1721:
173
174	REMAP(4, 1, 2)
175	REMAP(5, 1, 2)
176	REMAP(6, 1, 2)
177	REMAP(7, 1, 2)
178
179#undef REMAP
180
181/* Initial setup. */
182
183	ba	stage2
184
185stage2:
186
187#ifdef PPC_4XX_NOCACHE
188	li	0,0
189#else
190	lis	0,0xfffc
191#endif
192	mtdccr	0
193	mticcr	0
194	sync
195	isync
196
197/* get start of bss */
198	lis	7,_C_LABEL(edata)-4@h
199	ori	7,7,_C_LABEL(edata)-4@l
200/* get end of kernel */
201	lis	4,_C_LABEL(end)@h
202	ori	4,4,_C_LABEL(end)@l
203/* clear bss */
204	li	3,0
2051:
206	stwu	3,4(7)
207	cmpw	7,4
208	bne+	1b
209
210	INIT_CPUINFO(4,1,9,0)
211
212	lis	3,__start@h
213	ori	3,3,__start@l
214
215/* Run the remaining setup in C. */
216	bl	_C_LABEL(bootstrap)
217
218	bl	_C_LABEL(main)
219
220	/* NOTREACHED */
2212:	nop
222	b	2b
223
224stage1size = .-__start
225
226#include <powerpc/ibm4xx/4xx_locore.S>
227