107 lines
2.2 KiB
ArmAsm
107 lines
2.2 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* arch/powerpc/boot/gamecube-head.S
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*
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* Nintendo GameCube bootwrapper entry.
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* Copyright (C) 2004-2009 The GameCube Linux Team
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* Copyright (C) 2008,2009 Albert Herranz
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*/
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#include "ppc_asm.h"
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/*
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* The entry code does no assumptions regarding:
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* - if the data and instruction caches are enabled or not
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* - if the MMU is enabled or not
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*
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* We enable the caches if not already enabled, enable the MMU with an
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* identity mapping scheme and jump to the start code.
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*/
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.text
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.globl _zimage_start
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_zimage_start:
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/* turn the MMU off */
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mfmsr 9
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rlwinm 9, 9, 0, ~((1<<4)|(1<<5)) /* MSR_DR|MSR_IR */
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bcl 20, 31, 1f
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1:
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mflr 8
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clrlwi 8, 8, 3 /* convert to a real address */
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addi 8, 8, _mmu_off - 1b
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mtsrr0 8
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mtsrr1 9
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rfi
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_mmu_off:
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/* MMU disabled */
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/* setup BATs */
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isync
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li 8, 0
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mtspr 0x210, 8 /* IBAT0U */
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mtspr 0x212, 8 /* IBAT1U */
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mtspr 0x214, 8 /* IBAT2U */
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mtspr 0x216, 8 /* IBAT3U */
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mtspr 0x218, 8 /* DBAT0U */
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mtspr 0x21a, 8 /* DBAT1U */
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mtspr 0x21c, 8 /* DBAT2U */
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mtspr 0x21e, 8 /* DBAT3U */
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li 8, 0x01ff /* first 16MiB */
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li 9, 0x0002 /* rw */
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mtspr 0x211, 9 /* IBAT0L */
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mtspr 0x210, 8 /* IBAT0U */
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mtspr 0x219, 9 /* DBAT0L */
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mtspr 0x218, 8 /* DBAT0U */
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lis 8, 0x0c00 /* I/O mem */
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ori 8, 8, 0x3ff /* 32MiB */
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lis 9, 0x0c00
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ori 9, 9, 0x002a /* uncached, guarded, rw */
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mtspr 0x21b, 9 /* DBAT1L */
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mtspr 0x21a, 8 /* DBAT1U */
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lis 8, 0x0100 /* next 8MiB */
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ori 8, 8, 0x00ff /* 8MiB */
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lis 9, 0x0100
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ori 9, 9, 0x0002 /* rw */
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mtspr 0x215, 9 /* IBAT2L */
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mtspr 0x214, 8 /* IBAT2U */
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mtspr 0x21d, 9 /* DBAT2L */
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mtspr 0x21c, 8 /* DBAT2U */
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/* enable and invalidate the caches if not already enabled */
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mfspr 8, 0x3f0 /* HID0 */
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andi. 0, 8, (1<<15) /* HID0_ICE */
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bne 1f
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ori 8, 8, (1<<15)|(1<<11) /* HID0_ICE|HID0_ICFI*/
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1:
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andi. 0, 8, (1<<14) /* HID0_DCE */
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bne 1f
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ori 8, 8, (1<<14)|(1<<10) /* HID0_DCE|HID0_DCFI*/
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1:
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mtspr 0x3f0, 8 /* HID0 */
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isync
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/* initialize arguments */
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li 3, 0
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li 4, 0
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li 5, 0
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/* turn the MMU on */
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bcl 20, 31, 1f
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1:
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mflr 8
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addi 8, 8, _mmu_on - 1b
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mfmsr 9
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ori 9, 9, (1<<4)|(1<<5) /* MSR_DR|MSR_IR */
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mtsrr0 8
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mtsrr1 9
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sync
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rfi
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_mmu_on:
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b _zimage_start_lib
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