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2874c5fd | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
b68a24bc AH |
2 | /* |
3 | * arch/powerpc/boot/gamecube-head.S | |
4 | * | |
5 | * Nintendo GameCube bootwrapper entry. | |
6 | * Copyright (C) 2004-2009 The GameCube Linux Team | |
7 | * Copyright (C) 2008,2009 Albert Herranz | |
b68a24bc AH |
8 | */ |
9 | ||
10 | #include "ppc_asm.h" | |
11 | ||
12 | /* | |
13 | * The entry code does no assumptions regarding: | |
14 | * - if the data and instruction caches are enabled or not | |
15 | * - if the MMU is enabled or not | |
16 | * | |
17 | * We enable the caches if not already enabled, enable the MMU with an | |
18 | * identity mapping scheme and jump to the start code. | |
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)) /* MSR_DR|MSR_IR */ | |
29 | bcl 20, 31, 1f | |
30 | 1: | |
31 | mflr 8 | |
32 | clrlwi 8, 8, 3 /* convert to a real address */ | |
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, guarded, rw */ | |
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 not already enabled */ | |
76 | mfspr 8, 0x3f0 /* HID0 */ | |
77 | andi. 0, 8, (1<<15) /* HID0_ICE */ | |
78 | bne 1f | |
79 | ori 8, 8, (1<<15)|(1<<11) /* HID0_ICE|HID0_ICFI*/ | |
80 | 1: | |
81 | andi. 0, 8, (1<<14) /* HID0_DCE */ | |
82 | bne 1f | |
83 | ori 8, 8, (1<<14)|(1<<10) /* HID0_DCE|HID0_DCFI*/ | |
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|MSR_IR */ | |
100 | mtsrr0 8 | |
101 | mtsrr1 9 | |
102 | sync | |
103 | rfi | |
104 | _mmu_on: | |
105 | b _zimage_start_lib | |
106 |