xref: /netbsd-src/sys/arch/evbarm/mmnet/mmnet_start.S (revision 6a493d6bc668897c91594964a732d38505b70cbb)
1/*	$NetBSD: mmnet_start.S,v 1.1 2011/11/04 17:40:48 aymeric Exp $ */
2/*
3 * Copyright (C) 2005, 2006 WIDE Project and SOUM Corporation.
4 * All rights reserved.
5 *
6 * Written by Takashi Kiyohara and Susumu Miki for WIDE Project and SOUM
7 * Corporation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the project nor the name of SOUM Corporation
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT and SOUM CORPORATION ``AS IS''
22 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT AND SOUM CORPORATION
25 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31 * POSSIBILITY OF SUCH DAMAGE.
32 */
33/*
34 * Copyright (c) 2002, 2003  Genetec Corporation.  All rights reserved.
35 * Written by Hiroyuki Bessho for Genetec Corporation.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 *    notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 *    notice, this list of conditions and the following disclaimer in the
44 *    documentation and/or other materials provided with the distribution.
45 * 3. The name of Genetec Corporation may not be used to endorse or
46 *    promote products derived from this software without specific prior
47 *    written permission.
48 *
49 * THIS SOFTWARE IS PROVIDED BY GENETEC CORPORATION ``AS IS'' AND
50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
51 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
52 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL GENETEC CORPORATION
53 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
54 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
55 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
56 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
57 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
58 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
59 * POSSIBILITY OF SUCH DAMAGE.
60 */
61
62#include <machine/asm.h>
63#include <arm/armreg.h>
64#include <arm/arm32/pte.h>
65#include <arm/arm32/pmap.h>		/* for PMAP_DOMAIN_KERNEL */
66
67#ifndef SDRAM_START
68#define SDRAM_START	0x20000000
69#endif
70
71/*
72 * CPWAIT -- Canonical method to wait for CP15 update.
73 * NOTE: Clobbers the specified temp reg.
74 * copied from arm/arm/cpufunc_asm_xscale.S
75 * XXX: better be in a common header file.
76 */
77#define	CPWAIT_BRANCH							 \
78	sub	pc, pc, #4
79
80#define	CPWAIT(tmp)							 \
81	mrc	p15, 0, tmp, c2, c0, 0	/* arbitrary read of CP15 */	;\
82	mov	tmp, tmp		/* wait for it to complete */	;\
83	CPWAIT_BRANCH			/* branch to next insn */
84
85/*
86 * Kernel start routine for the Propox MMnet 1002
87 * this code is executed at the very beginning after the kernel is loaded
88 * by U-Boot.
89 */
90	.text
91
92	.global	_C_LABEL(mmnet_start)
93_C_LABEL(mmnet_start):
94	/*
95	 *  Kernel is loaded in SDRAM (0x20200000), and is expected to run
96	 *  in VA 0xc0200000..
97	 */
98	/* save u-boot's args */
99	adr	r4, u_boot_args
100	nop
101	nop
102	nop
103	stmia	r4!, {r0, r1, r2, r3}
104	nop
105	nop
106	nop
107
108	/* Calculate RAM size */
109	adr	r4, ram_size
110	ldr	r0, [r4]
1110:
112	add	r3, r4, r0
113	ldr	r1, [r3]
114	cmp	r0, r1
115	beq	2f
1161:
117	add	r0, r0, r0	/* r0 <<= 1 */
118	str	r0, [r4]
119	b	0b
1202:
121	mvn	r1, r1		/* r1 ^= 0xffffffff */
122	str	r1, [r3]
123	ldr	r2, [r4]
124	cmp	r1, r2
125	beq	3f
126	str	r0, [r3]	/* restore */
127	b	1b
1283:
129	str	r0, [r4]
130
131	/* build page table from scratch */
132	ldr	r0, Lstartup_pagetable		/* pagetable */
133	adr	r4, mmu_init_table
134	b	5f
135
1364:
137	str	r3, [r0, r2]
138	add	r2, r2, #4
139	add	r3, r3, #(L1_S_SIZE)
140	adds	r1, r1, #-1
141	bhi	4b
1425:
143	ldmia	r4!, {r1, r2, r3}	/* # of sections, PA|attr, VA */
144	cmp	r1, #0
145	bne	4b
146
147	mcr	p15, 0, r0, c2, c0, 0	/* Set TTB */
148	mcr	p15, 0, r0, c8, c7, 0	/* Flush TLB */
149
150	/* Set the Domain Access register.  Very important! */
151        mov     r0, #((DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL*2)) | DOMAIN_CLIENT)
152	mcr	p15, 0, r0, c3, c0, 0
153
154	/* Enable MMU */
155	mrc	p15, 0, r0, c1, c0, 0
156	orr	r0, r0, #CPU_CONTROL_SYST_ENABLE
157	orr	r0, r0, #CPU_CONTROL_MMU_ENABLE
158	mcr	p15, 0, r0, c1, c0, 0
159	CPWAIT(r0)
160
161	/* Jump to kernel code in TRUE VA */
162	adr	r0, Lstart
163	ldr	pc, [r0]
164
165Lstart:
166	.word	start
167
168#ifndef STARTUP_PAGETABLE_ADDR
169#define STARTUP_PAGETABLE_ADDR 0x20000000	/* aligned 16kByte */
170#endif
171Lstartup_pagetable:
172	.word	STARTUP_PAGETABLE_ADDR
173
174	.globl	_C_LABEL(u_boot_args)
175u_boot_args:
176	.space	16			/* r0, r1, r2, r3 */
177
178	.globl	_C_LABEL(ram_size)
179ram_size:
180	.word	0x04000000		/* 64Mbyte */
181
182
183#define MMU_INIT(va,pa,n_sec,attr) \
184	.word	n_sec					    ; \
185	.word	4 * ((va) >> L1_S_SHIFT)		    ; \
186	.word	(pa) | (attr)				    ;
187
188mmu_init_table:
189	/* fill all table VA==PA */
190	MMU_INIT(0x00000000, 0x00000000,
191	    1 << (32 - L1_S_SHIFT), L1_TYPE_S | L1_S_AP(AP_KRW))
192
193	/* map SDRAM VA==PA, WT cacheable */
194	MMU_INIT(SDRAM_START, SDRAM_START,
195	    64, L1_TYPE_S | L1_S_C | L1_S_AP(AP_KRW))
196
197	/* map VA 0xc0000000..0xc3ffffff to PA 0x20000000..0x23ffffff */
198	MMU_INIT(0xc0000000, SDRAM_START,
199	    64, L1_TYPE_S | L1_S_C | L1_S_AP(AP_KRW))
200
201	.word	0			/* end of table */
202