| /* 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 |
| |
