1 /* SPDX-License-Identifier: GPL-2.0-or-later *
2 /*
3 * arch/powerpc/boot/gamecube-head.S
4 *
5 * Nintendo GameCube bootwrapper entry.
6 * Copyright (C) 2004-2009 The GameCube Linux
7 * Copyright (C) 2008,2009 Albert Herranz
8 */
9
10 #include "ppc_asm.h"
11
12 /*
13 * The entry code does no assumptions regardin
14 * - if the data and instruction caches are en
15 * - if the MMU is enabled or not
16 *
17 * We enable the caches if not already enabled
18 * identity mapping scheme and jump to the sta
19 */
20
21 .text
22
23 .globl _zimage_start
24 _zimage_start:
25
26 /* turn the MMU off */
27 mfmsr 9
28 rlwinm 9, 9, 0, ~((1<<4)|(1<<5)) /* M
29 bcl 20, 31, 1f
30 1:
31 mflr 8
32 clrlwi 8, 8, 3 /* convert to
33 addi 8, 8, _mmu_off - 1b
34 mtsrr0 8
35 mtsrr1 9
36 rfi
37 _mmu_off:
38 /* MMU disabled */
39
40 /* setup BATs */
41 isync
42 li 8, 0
43 mtspr 0x210, 8 /* IBAT0U */
44 mtspr 0x212, 8 /* IBAT1U */
45 mtspr 0x214, 8 /* IBAT2U */
46 mtspr 0x216, 8 /* IBAT3U */
47 mtspr 0x218, 8 /* DBAT0U */
48 mtspr 0x21a, 8 /* DBAT1U */
49 mtspr 0x21c, 8 /* DBAT2U */
50 mtspr 0x21e, 8 /* DBAT3U */
51
52 li 8, 0x01ff /* first 16MiB
53 li 9, 0x0002 /* rw */
54 mtspr 0x211, 9 /* IBAT0L */
55 mtspr 0x210, 8 /* IBAT0U */
56 mtspr 0x219, 9 /* DBAT0L */
57 mtspr 0x218, 8 /* DBAT0U */
58
59 lis 8, 0x0c00 /* I/O mem */
60 ori 8, 8, 0x3ff /* 32MiB */
61 lis 9, 0x0c00
62 ori 9, 9, 0x002a /* uncached, g
63 mtspr 0x21b, 9 /* DBAT1L */
64 mtspr 0x21a, 8 /* DBAT1U */
65
66 lis 8, 0x0100 /* next 8MiB *
67 ori 8, 8, 0x00ff /* 8MiB */
68 lis 9, 0x0100
69 ori 9, 9, 0x0002 /* rw */
70 mtspr 0x215, 9 /* IBAT2L */
71 mtspr 0x214, 8 /* IBAT2U */
72 mtspr 0x21d, 9 /* DBAT2L */
73 mtspr 0x21c, 8 /* DBAT2U */
74
75 /* enable and invalidate the caches if
76 mfspr 8, 0x3f0 /* HID0 */
77 andi. 0, 8, (1<<15) /* HID
78 bne 1f
79 ori 8, 8, (1<<15)|(1<<11) /* HID
80 1:
81 andi. 0, 8, (1<<14) /* HID
82 bne 1f
83 ori 8, 8, (1<<14)|(1<<10) /* HID
84 1:
85 mtspr 0x3f0, 8 /* HID0 */
86 isync
87
88 /* initialize arguments */
89 li 3, 0
90 li 4, 0
91 li 5, 0
92
93 /* turn the MMU on */
94 bcl 20, 31, 1f
95 1:
96 mflr 8
97 addi 8, 8, _mmu_on - 1b
98 mfmsr 9
99 ori 9, 9, (1<<4)|(1<<5) /* MSR_DR|
100 mtsrr0 8
101 mtsrr1 9
102 sync
103 rfi
104 _mmu_on:
105 b _zimage_start_lib
106
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