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-rw-r--r--arch/powerpc/boot/wii-head.S137
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diff --git a/arch/powerpc/boot/wii-head.S b/arch/powerpc/boot/wii-head.S
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+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * arch/powerpc/boot/wii-head.S
+ *
+ * Nintendo Wii bootwrapper entry.
+ * Copyright (C) 2008-2009 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
+ * - if the high BATs are enabled or not
+ *
+ * We enable the high BATs, 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 */
+
+ mtspr 0x230, 8 /* IBAT4U */
+ mtspr 0x232, 8 /* IBAT5U */
+ mtspr 0x234, 8 /* IBAT6U */
+ mtspr 0x236, 8 /* IBAT7U */
+ mtspr 0x238, 8 /* DBAT4U */
+ mtspr 0x23a, 8 /* DBAT5U */
+ mtspr 0x23c, 8 /* DBAT6U */
+ mtspr 0x23e, 8 /* DBAT7U */
+
+ 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 */
+
+ lis 8, 0x1000 /* MEM2 */
+ ori 8, 8, 0x07ff /* 64MiB */
+ lis 9, 0x1000
+ ori 9, 9, 0x0002 /* rw */
+ mtspr 0x216, 8 /* IBAT3U */
+ mtspr 0x217, 9 /* IBAT3L */
+ mtspr 0x21e, 8 /* DBAT3U */
+ mtspr 0x21f, 9 /* DBAT3L */
+
+ /* enable the high BATs */
+ mfspr 8, 0x3f3 /* HID4 */
+ oris 8, 8, 0x0200
+ mtspr 0x3f3, 8 /* HID4 */
+
+ /* 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:
+ /* turn on the front blue led (aka: yay! we got here!) */
+ lis 8, 0x0d00
+ ori 8, 8, 0x00c0
+ lwz 9, 0(8)
+ ori 9, 9, 0x20
+ stw 9, 0(8)
+
+ b _zimage_start_lib
+