xref: /OK3568_Linux_fs/kernel/arch/powerpc/boot/wii-head.S (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun/* SPDX-License-Identifier: GPL-2.0-or-later */
2*4882a593Smuzhiyun/*
3*4882a593Smuzhiyun * arch/powerpc/boot/wii-head.S
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Nintendo Wii bootwrapper entry.
6*4882a593Smuzhiyun * Copyright (C) 2008-2009 The GameCube Linux Team
7*4882a593Smuzhiyun * Copyright (C) 2008,2009 Albert Herranz
8*4882a593Smuzhiyun */
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun#include "ppc_asm.h"
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun/*
13*4882a593Smuzhiyun * The entry code does no assumptions regarding:
14*4882a593Smuzhiyun * - if the data and instruction caches are enabled or not
15*4882a593Smuzhiyun * - if the MMU is enabled or not
16*4882a593Smuzhiyun * - if the high BATs are enabled or not
17*4882a593Smuzhiyun *
18*4882a593Smuzhiyun * We enable the high BATs, enable the caches if not already enabled,
19*4882a593Smuzhiyun * enable the MMU with an identity mapping scheme and jump to the start code.
20*4882a593Smuzhiyun */
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun	.text
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun	.globl _zimage_start
25*4882a593Smuzhiyun_zimage_start:
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun	/* turn the MMU off */
28*4882a593Smuzhiyun	mfmsr	9
29*4882a593Smuzhiyun	rlwinm	9, 9, 0, ~((1<<4)|(1<<5)) /* MSR_DR|MSR_IR */
30*4882a593Smuzhiyun	bcl	20, 31, 1f
31*4882a593Smuzhiyun1:
32*4882a593Smuzhiyun	mflr	8
33*4882a593Smuzhiyun	clrlwi	8, 8, 3		/* convert to a real address */
34*4882a593Smuzhiyun	addi	8, 8, _mmu_off - 1b
35*4882a593Smuzhiyun	mtsrr0	8
36*4882a593Smuzhiyun	mtsrr1	9
37*4882a593Smuzhiyun	rfi
38*4882a593Smuzhiyun_mmu_off:
39*4882a593Smuzhiyun	/* MMU disabled */
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun	/* setup BATs */
42*4882a593Smuzhiyun	isync
43*4882a593Smuzhiyun	li      8, 0
44*4882a593Smuzhiyun	mtspr	0x210, 8	/* IBAT0U */
45*4882a593Smuzhiyun	mtspr	0x212, 8	/* IBAT1U */
46*4882a593Smuzhiyun	mtspr	0x214, 8	/* IBAT2U */
47*4882a593Smuzhiyun	mtspr	0x216, 8	/* IBAT3U */
48*4882a593Smuzhiyun	mtspr	0x218, 8	/* DBAT0U */
49*4882a593Smuzhiyun	mtspr	0x21a, 8	/* DBAT1U */
50*4882a593Smuzhiyun	mtspr	0x21c, 8	/* DBAT2U */
51*4882a593Smuzhiyun	mtspr	0x21e, 8	/* DBAT3U */
52*4882a593Smuzhiyun
53*4882a593Smuzhiyun	mtspr	0x230, 8	/* IBAT4U */
54*4882a593Smuzhiyun	mtspr	0x232, 8	/* IBAT5U */
55*4882a593Smuzhiyun	mtspr	0x234, 8	/* IBAT6U */
56*4882a593Smuzhiyun	mtspr	0x236, 8	/* IBAT7U */
57*4882a593Smuzhiyun	mtspr	0x238, 8	/* DBAT4U */
58*4882a593Smuzhiyun	mtspr	0x23a, 8	/* DBAT5U */
59*4882a593Smuzhiyun	mtspr	0x23c, 8	/* DBAT6U */
60*4882a593Smuzhiyun	mtspr	0x23e, 8	/* DBAT7U */
61*4882a593Smuzhiyun
62*4882a593Smuzhiyun	li	8, 0x01ff	/* first 16MiB */
63*4882a593Smuzhiyun	li	9, 0x0002	/* rw */
64*4882a593Smuzhiyun	mtspr	0x211, 9	/* IBAT0L */
65*4882a593Smuzhiyun	mtspr	0x210, 8	/* IBAT0U */
66*4882a593Smuzhiyun	mtspr	0x219, 9	/* DBAT0L */
67*4882a593Smuzhiyun	mtspr	0x218, 8	/* DBAT0U */
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun	lis	8, 0x0c00	/* I/O mem */
70*4882a593Smuzhiyun	ori	8, 8, 0x3ff	/* 32MiB */
71*4882a593Smuzhiyun	lis	9, 0x0c00
72*4882a593Smuzhiyun	ori	9, 9, 0x002a	/* uncached, guarded, rw */
73*4882a593Smuzhiyun	mtspr	0x21b, 9	/* DBAT1L */
74*4882a593Smuzhiyun	mtspr	0x21a, 8	/* DBAT1U */
75*4882a593Smuzhiyun
76*4882a593Smuzhiyun	lis	8, 0x0100	/* next 8MiB */
77*4882a593Smuzhiyun	ori	8, 8, 0x00ff	/* 8MiB */
78*4882a593Smuzhiyun	lis	9, 0x0100
79*4882a593Smuzhiyun	ori	9, 9, 0x0002	/* rw */
80*4882a593Smuzhiyun	mtspr	0x215, 9	/* IBAT2L */
81*4882a593Smuzhiyun	mtspr	0x214, 8	/* IBAT2U */
82*4882a593Smuzhiyun	mtspr	0x21d, 9	/* DBAT2L */
83*4882a593Smuzhiyun	mtspr	0x21c, 8	/* DBAT2U */
84*4882a593Smuzhiyun
85*4882a593Smuzhiyun	lis	8, 0x1000	/* MEM2 */
86*4882a593Smuzhiyun	ori	8, 8, 0x07ff	/* 64MiB */
87*4882a593Smuzhiyun	lis	9, 0x1000
88*4882a593Smuzhiyun	ori	9, 9, 0x0002	/* rw */
89*4882a593Smuzhiyun	mtspr	0x216, 8	/* IBAT3U */
90*4882a593Smuzhiyun	mtspr	0x217, 9	/* IBAT3L */
91*4882a593Smuzhiyun	mtspr	0x21e, 8	/* DBAT3U */
92*4882a593Smuzhiyun	mtspr	0x21f, 9	/* DBAT3L */
93*4882a593Smuzhiyun
94*4882a593Smuzhiyun	/* enable the high BATs */
95*4882a593Smuzhiyun	mfspr	8, 0x3f3	/* HID4 */
96*4882a593Smuzhiyun	oris	8, 8, 0x0200
97*4882a593Smuzhiyun	mtspr	0x3f3, 8	/* HID4 */
98*4882a593Smuzhiyun
99*4882a593Smuzhiyun	/* enable and invalidate the caches if not already enabled */
100*4882a593Smuzhiyun	mfspr	8, 0x3f0	/* HID0 */
101*4882a593Smuzhiyun	andi.	0, 8, (1<<15)		/* HID0_ICE */
102*4882a593Smuzhiyun	bne	1f
103*4882a593Smuzhiyun	ori	8, 8, (1<<15)|(1<<11)	/* HID0_ICE|HID0_ICFI*/
104*4882a593Smuzhiyun1:
105*4882a593Smuzhiyun	andi.	0, 8, (1<<14)		/* HID0_DCE */
106*4882a593Smuzhiyun	bne	1f
107*4882a593Smuzhiyun	ori	8, 8, (1<<14)|(1<<10)	/* HID0_DCE|HID0_DCFI*/
108*4882a593Smuzhiyun1:
109*4882a593Smuzhiyun	mtspr	0x3f0, 8	/* HID0 */
110*4882a593Smuzhiyun	isync
111*4882a593Smuzhiyun
112*4882a593Smuzhiyun	/* initialize arguments */
113*4882a593Smuzhiyun	li	3, 0
114*4882a593Smuzhiyun	li	4, 0
115*4882a593Smuzhiyun	li	5, 0
116*4882a593Smuzhiyun
117*4882a593Smuzhiyun	/* turn the MMU on */
118*4882a593Smuzhiyun	bcl	20, 31, 1f
119*4882a593Smuzhiyun1:
120*4882a593Smuzhiyun	mflr	8
121*4882a593Smuzhiyun	addi	8, 8, _mmu_on - 1b
122*4882a593Smuzhiyun	mfmsr	9
123*4882a593Smuzhiyun	ori	9, 9, (1<<4)|(1<<5) /* MSR_DR|MSR_IR */
124*4882a593Smuzhiyun	mtsrr0	8
125*4882a593Smuzhiyun	mtsrr1	9
126*4882a593Smuzhiyun	sync
127*4882a593Smuzhiyun	rfi
128*4882a593Smuzhiyun_mmu_on:
129*4882a593Smuzhiyun	/* turn on the front blue led (aka: yay! we got here!) */
130*4882a593Smuzhiyun	lis	8, 0x0d00
131*4882a593Smuzhiyun	ori	8, 8, 0x00c0
132*4882a593Smuzhiyun	lwz	9, 0(8)
133*4882a593Smuzhiyun	ori	9, 9, 0x20
134*4882a593Smuzhiyun	stw	9, 0(8)
135*4882a593Smuzhiyun
136*4882a593Smuzhiyun	b _zimage_start_lib
137*4882a593Smuzhiyun
138