1/*	$NetBSD: imx31lk_start.S,v 1.3 2009/11/05 16:28:09 uebayasi Exp $	*/
2/*-
3 * Copyright (c) 2011 The NetBSD Foundation, Inc.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to The NetBSD Foundation
7 * by Matt Thomas of 3am Software Foundry.
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 *
18 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <machine/asm.h>
32#include <arm/armreg.h>
33#include "assym.h"
34
35RCSID("$NetBSD$")
36
37/*
38 */
39
40#define CPWAIT_BRANCH							 \
41	sub	pc, pc, #4
42
43#define CPWAIT(tmp)							 \
44	mrc	p15, 0, tmp, c2, c0, 0  /* arbitrary read of CP15 */	;\
45	mov	tmp, tmp		/* wait for it to complete */	;\
46	CPWAIT_BRANCH			/* branch to next insn */
47
48
49#ifndef SDRAM_START
50#define SDRAM_START 0x80000000
51#endif
52
53#define IMX31_DCACHE_SIZE 0x4000	/* 16KB L1 */
54
55/*
56 * L1 == "Level One" == "first-level"
57 * L2 == "Level Two" == "second-level"
58 */
59
60	.text
61
62	.global _C_LABEL(imx31lk_start)
63_C_LABEL(imx31lk_start):
64	/* Figure out where we want to jump to when the time comes */
65	adr	r8, .Lstart
66	ldr	r8, [r8]
67
68	/*
69	 * set up virtual address space mapping
70	 * for initial bootstrap.
71	 */
72	mov     r2, #(L1_S_SIZE)		/* 1MB chunks */
73
74	/*
75	 * Firmware already mapped SDRAM VA == PA. at 0x800..
76	 * now map SDRAM also at VA 0x800...
77	 */
78	mrc	p15, 0, r0, c2, c0, 0		/* L1 table addr into r0 */
79	add	r0, r0, #(0x800 * 4)		/* offset to 0x80000000 */
80
81	mov	r3, #SDRAM_START		/* map to 0x800.. */
82	orr	r3, r3, #(L1_S_AP_KRW)		/* the usual perms & stuff */
83	orr	r3, r3, #(L1_TYPE_S)
84	orr	r3, r3, #(L1_S_DOM_KERNEL)
85
86	mov	r1, #0x80			/* 128 1MB entries */
871:
88	/* and looplooploop */
89	str	r3, [r0], #4
90	add	r3, r3, r2
91	subs	r1, r1, #1
92	bgt	1b
93
94	/*
95	 * Map an L1 section for each device to make this easy.
96	 */
97	/* UART1 */
98	mrc	p15, 0, r0, c2, c0, 0		/* L1 table addr into r0 */
99	add	r0, r0, #(0xfd0 * 4)		/* offset to 0xfd000000 */
100
101	mov	r3,	#0x43000000
102	orr	r3, r3,	#0x00f00000
103	orr	r3, r3, #(L1_S_AP_KRW)
104	orr	r3, r3, #(L1_TYPE_S)
105	orr	r3, r3, #(L1_S_DOM_KERNEL)
106	str	r3, [r0], #4			/* note autoinc */
107
108	/* etc, TBD... */
109
110	/*
111	 * Make domain control go full art.
112	 */
113	mov	r0, #0xffffffff
114	mcr	p15, 0, r0, c3, c0, 0
115
116	/*
117	 * Now let's clean the cache again to make sure everything
118	 * is in place.
119	 *
120	 * XXX: should this take into account the XScale cache clean bug?
121	 */
122	mov	r3, #(IMX31_DCACHE_SIZE)
123	subs	r3, r3, #32
1241:
125	mcr	p15, 0, r3, c7, c10, 2
126	subs	r3, r3, #32
127	bne	1b
128	CPWAIT(r3)
129
130	/* Drain write buffer */
131	mcr	p15, 0, r6, c7, c10, 4
132
133	/* Invalidate TLBs just to be sure */
134	mcr     p15, 0, r0, c8, c7, 0
135
136	/*
137	 * You are standing at the gate to NetBSD. --More--
138	 * Unspeakable cruelty and harm lurk down there. --More--
139	 * Are you sure you want to enter?
140	 */
141	adr	r8, .Lstart
142	ldr	r8, [r8]
143	mov	pc, r8				/* So be it */
144
145/* symbol to use for address calculation in the right VA */
146.Lstart:
147	.word	start
148
149
150/*
151 * Calculate size of kernel to copy.  Don't bother to copy bss,
152 * although I guess the CPU could use the warmup exercise ...
153 */
154.Lcopy_size:
155        .word _edata - _C_LABEL(imx31lk_start)
156
157