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