233 lines
5.0 KiB
ArmAsm
233 lines
5.0 KiB
ArmAsm
/* $NetBSD: pbr.S,v 1.2 2012/01/21 19:44:30 nonaka Exp $ */
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/*-
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* Copyright (C) 2005 NONAKA Kimihiro <nonaka@netbsd.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <machine/asm.h>
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#include <sys/bootblock.h>
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#ifdef BOOT_FROM_FAT
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#define MBR_AFTERBPB 90 /* BPB size in FAT32 partition BR */
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#else
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#define MBR_AFTERBPB 62 /* BPB size in floppy master BR */
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#endif
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ENTRY(start)
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bra start0
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.byte 0x11 /* 0x4e11: cmp/pz r14... */
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.ascii "NetBSD20"
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. = _C_LABEL(start) + MBR_BPB_OFFSET /* move to start of BPB */
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. = _C_LABEL(start) + MBR_AFTERBPB /* skip BPB */
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start0:
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mova mbr_end, r0
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mov.w mbr_size, r2
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sub r2, r0
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mov r0, r11 /* r11: own loaded address */
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mov.w stack_offset, r1
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add r1, r0
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mov r0, r15 /* r15: stack pointer */
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mov r0, r10 /* r10: load address */
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/* enable/flush cache */
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mov #0, r4
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mov #6, r0
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trapa #0x3f
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/* Read from start of disk */
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mov #0x40, r4 /* LBA */
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mov #0, r5 /* LBA #0 */
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mov r10, r6 /* buffer address */
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bsr read_sectors_lba
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mov #BOOTXX_SECTORS, r7 /* number of sectors */
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mov.l @r11, r1
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mov.l @r10, r2
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cmp/eq r1, r2
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bt/s pbr_read_ok
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mov #0, r9 /* r9: sector # */
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/* Search bootable partition */
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mov.w part_offset, r12
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add r10, r12 /* r12: pointer to partition entry */
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mov #MBR_PART_COUNT, r8 /* r8: partition loop counter */
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loop_part:
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mov.b @(4, r12), r0
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#ifdef BOOT_FROM_FAT
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cmp/eq #MBR_PTYPE_FAT12, r0
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bt found
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cmp/eq #MBR_PTYPE_FAT16S, r0
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bt found
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cmp/eq #MBR_PTYPE_FAT16B, r0
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bt found
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cmp/eq #MBR_PTYPE_FAT32, r0
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bt found
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cmp/eq #MBR_PTYPE_FAT32L, r0
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bt found
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cmp/eq #MBR_PTYPE_FAT16L, r0
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bt found
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#else
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cmp/eq #MBR_PTYPE_NETBSD, r0
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#endif
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bf next_part
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found:
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/* found boot partition */
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mov.w @(8, r12), r0
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mov r0, r1
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mov.w @(10, r12), r0
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extu.w r1, r1
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shll16 r0
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or r1, r0
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tst r0, r0
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bt next_part /* start LBA == 0 ? */
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bra boot_lba
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mov r0, r9
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next_part:
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dt r8
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bf/s loop_part
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add #16, r12
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ptn_error:
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/* Not found NetBSD partition */
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mova ERR_PTN, r0
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error:
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bsr message_crlf
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mov r0, r4
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99: bra 99b
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nop
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read_error:
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bra error
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mova ERR_READ, r0
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magic_error:
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bra error
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mova ERR_NO_BOOTXX, r0
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message_crlf:
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mov #32, r0
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trapa #0x3f
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mova crlf, r0
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mov r0, r4
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mov #32, r0
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trapa #0x3f
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rts
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nop
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read_sectors_lba:
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mov #2, r0
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trapa #0x3f
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tst r0, r0
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bf read_error
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rts
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nop
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boot_lba:
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mov #0x40, r4 /* LBA */
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mov r9, r5 /* LBA # */
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mov r10, r6 /* buffer address */
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bsr read_sectors_lba
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mov #BOOTXX_SECTORS, r7 /* number of sectors */
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pbr_read_ok:
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mov.l .L.bootxx_magic1, r1
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mov.l .L.bootxx_magic, r2
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mov.l @r2, r2
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cmp/eq r1, r2
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bf magic_error
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/* flush cache */
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mov #0, r4
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mov #6, r0
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trapa #0x3f
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mov.l .L.bootxx_start, r13
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jmp @r13 /* jump to bootxx */
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mov r9, r4 /* pass sector address to bootxx */
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.align 1
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mbr_size: .word mbr_end - _C_LABEL(start)
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.align 1
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stack_offset: .word 0x1000
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.align 1
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part_offset: .word MBR_PART_OFFSET
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.align 1
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magic_offset: .word MBR_MAGIC_OFFSET
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.align 2
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.L.bootxx_magic1:
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.long LANDISK_BOOT_MAGIC_1
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.L.bootxx_magic:
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.long _C_LABEL(bootxx_magic)
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.L.bootxx_start:
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.long _C_LABEL(bootxx_start)
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.align 2
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crlf: .asciz "\r\n"
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.align 2
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ERR_READ: .asciz "Disk read"
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.align 2
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ERR_NO_BOOTXX: .asciz "Not a bootxx image"
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.align 2
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ERR_PTN: .asciz "No NetBSD partition"
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/* space for mbr_dsn */
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. = _C_LABEL(start) + MBR_DSN_OFFSET
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.long 0
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/* mbr_bootsel_magic */
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. = _C_LABEL(start) + MBR_BS_MAGIC_OFFSET
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.word 0
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/*
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* MBR partition table
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*/
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. = _C_LABEL(start) + MBR_PART_OFFSET
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_pbr_part0:
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.byte 0, 0, 0, 0, 0, 0, 0, 0
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.byte 0, 0, 0, 0, 0, 0, 0, 0
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_pbr_part1:
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.byte 0, 0, 0, 0, 0, 0, 0, 0
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.byte 0, 0, 0, 0, 0, 0, 0, 0
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_pbr_part2:
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.byte 0, 0, 0, 0, 0, 0, 0, 0
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.byte 0, 0, 0, 0, 0, 0, 0, 0
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_pbr_part3:
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.byte 0, 0, 0, 0, 0, 0, 0, 0
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.byte 0, 0, 0, 0, 0, 0, 0, 0
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. = _C_LABEL(start) + MBR_MAGIC_OFFSET
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magic:
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.word MBR_MAGIC
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mbr_end:
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