forked from Minki/linux
0a2fe19ccc
Pul x86/efi changes from Ingo Molnar: "This tree adds an EFI bootloader handover protocol, which, once supported on the bootloader side, will make bootup faster and might result in simpler bootloaders. The other change activates the EFI wall clock time accessors on x86-64 as well, instead of the legacy RTC readout." * 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, efi: Handover Protocol x86-64/efi: Use EFI to deal with platform wall clock
486 lines
12 KiB
ArmAsm
486 lines
12 KiB
ArmAsm
/*
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* header.S
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* Based on bootsect.S and setup.S
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* modified by more people than can be counted
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*
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* Rewritten as a common file by H. Peter Anvin (Apr 2007)
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*
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* BIG FAT NOTE: We're in real mode using 64k segments. Therefore segment
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* addresses must be multiplied by 16 to obtain their respective linear
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* addresses. To avoid confusion, linear addresses are written using leading
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* hex while segment addresses are written as segment:offset.
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*
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*/
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#include <asm/segment.h>
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#include <generated/utsrelease.h>
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#include <asm/boot.h>
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#include <asm/e820.h>
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#include <asm/page_types.h>
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#include <asm/setup.h>
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#include "boot.h"
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#include "voffset.h"
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#include "zoffset.h"
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BOOTSEG = 0x07C0 /* original address of boot-sector */
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SYSSEG = 0x1000 /* historical load address >> 4 */
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#ifndef SVGA_MODE
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#define SVGA_MODE ASK_VGA
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#endif
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#ifndef RAMDISK
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#define RAMDISK 0
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#endif
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#ifndef ROOT_RDONLY
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#define ROOT_RDONLY 1
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#endif
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.code16
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.section ".bstext", "ax"
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.global bootsect_start
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bootsect_start:
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#ifdef CONFIG_EFI_STUB
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# "MZ", MS-DOS header
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.byte 0x4d
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.byte 0x5a
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#endif
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# Normalize the start address
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ljmp $BOOTSEG, $start2
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start2:
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movw %cs, %ax
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movw %ax, %ds
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movw %ax, %es
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movw %ax, %ss
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xorw %sp, %sp
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sti
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cld
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movw $bugger_off_msg, %si
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msg_loop:
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lodsb
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andb %al, %al
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jz bs_die
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movb $0xe, %ah
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movw $7, %bx
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int $0x10
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jmp msg_loop
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bs_die:
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# Allow the user to press a key, then reboot
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xorw %ax, %ax
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int $0x16
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int $0x19
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# int 0x19 should never return. In case it does anyway,
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# invoke the BIOS reset code...
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ljmp $0xf000,$0xfff0
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#ifdef CONFIG_EFI_STUB
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.org 0x3c
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#
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# Offset to the PE header.
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#
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.long pe_header
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#endif /* CONFIG_EFI_STUB */
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.section ".bsdata", "a"
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bugger_off_msg:
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.ascii "Direct floppy boot is not supported. "
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.ascii "Use a boot loader program instead.\r\n"
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.ascii "\n"
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.ascii "Remove disk and press any key to reboot ...\r\n"
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.byte 0
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#ifdef CONFIG_EFI_STUB
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pe_header:
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.ascii "PE"
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.word 0
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coff_header:
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#ifdef CONFIG_X86_32
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.word 0x14c # i386
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#else
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.word 0x8664 # x86-64
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#endif
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.word 3 # nr_sections
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.long 0 # TimeDateStamp
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.long 0 # PointerToSymbolTable
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.long 1 # NumberOfSymbols
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.word section_table - optional_header # SizeOfOptionalHeader
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#ifdef CONFIG_X86_32
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.word 0x306 # Characteristics.
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# IMAGE_FILE_32BIT_MACHINE |
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# IMAGE_FILE_DEBUG_STRIPPED |
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# IMAGE_FILE_EXECUTABLE_IMAGE |
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# IMAGE_FILE_LINE_NUMS_STRIPPED
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#else
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.word 0x206 # Characteristics
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# IMAGE_FILE_DEBUG_STRIPPED |
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# IMAGE_FILE_EXECUTABLE_IMAGE |
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# IMAGE_FILE_LINE_NUMS_STRIPPED
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#endif
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optional_header:
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#ifdef CONFIG_X86_32
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.word 0x10b # PE32 format
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#else
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.word 0x20b # PE32+ format
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#endif
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.byte 0x02 # MajorLinkerVersion
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.byte 0x14 # MinorLinkerVersion
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# Filled in by build.c
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.long 0 # SizeOfCode
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.long 0 # SizeOfInitializedData
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.long 0 # SizeOfUninitializedData
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# Filled in by build.c
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.long 0x0000 # AddressOfEntryPoint
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.long 0x0200 # BaseOfCode
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#ifdef CONFIG_X86_32
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.long 0 # data
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#endif
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extra_header_fields:
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#ifdef CONFIG_X86_32
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.long 0 # ImageBase
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#else
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.quad 0 # ImageBase
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#endif
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.long 0x20 # SectionAlignment
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.long 0x20 # FileAlignment
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.word 0 # MajorOperatingSystemVersion
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.word 0 # MinorOperatingSystemVersion
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.word 0 # MajorImageVersion
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.word 0 # MinorImageVersion
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.word 0 # MajorSubsystemVersion
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.word 0 # MinorSubsystemVersion
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.long 0 # Win32VersionValue
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#
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# The size of the bzImage is written in tools/build.c
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#
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.long 0 # SizeOfImage
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.long 0x200 # SizeOfHeaders
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.long 0 # CheckSum
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.word 0xa # Subsystem (EFI application)
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.word 0 # DllCharacteristics
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#ifdef CONFIG_X86_32
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.long 0 # SizeOfStackReserve
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.long 0 # SizeOfStackCommit
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.long 0 # SizeOfHeapReserve
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.long 0 # SizeOfHeapCommit
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#else
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.quad 0 # SizeOfStackReserve
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.quad 0 # SizeOfStackCommit
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.quad 0 # SizeOfHeapReserve
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.quad 0 # SizeOfHeapCommit
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#endif
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.long 0 # LoaderFlags
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.long 0x6 # NumberOfRvaAndSizes
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.quad 0 # ExportTable
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.quad 0 # ImportTable
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.quad 0 # ResourceTable
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.quad 0 # ExceptionTable
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.quad 0 # CertificationTable
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.quad 0 # BaseRelocationTable
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# Section table
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section_table:
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#
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# The offset & size fields are filled in by build.c.
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#
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.ascii ".setup"
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.byte 0
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.byte 0
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.long 0
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.long 0x0 # startup_{32,64}
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.long 0 # Size of initialized data
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# on disk
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.long 0x0 # startup_{32,64}
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.long 0 # PointerToRelocations
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.long 0 # PointerToLineNumbers
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.word 0 # NumberOfRelocations
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.word 0 # NumberOfLineNumbers
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.long 0x60500020 # Characteristics (section flags)
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#
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# The EFI application loader requires a relocation section
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# because EFI applications must be relocatable. The .reloc
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# offset & size fields are filled in by build.c.
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#
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.ascii ".reloc"
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.byte 0
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.byte 0
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.long 0
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.long 0
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.long 0 # SizeOfRawData
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.long 0 # PointerToRawData
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.long 0 # PointerToRelocations
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.long 0 # PointerToLineNumbers
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.word 0 # NumberOfRelocations
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.word 0 # NumberOfLineNumbers
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.long 0x42100040 # Characteristics (section flags)
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#
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# The offset & size fields are filled in by build.c.
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#
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.ascii ".text"
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.byte 0
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.byte 0
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.byte 0
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.long 0
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.long 0x0 # startup_{32,64}
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.long 0 # Size of initialized data
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# on disk
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.long 0x0 # startup_{32,64}
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.long 0 # PointerToRelocations
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.long 0 # PointerToLineNumbers
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.word 0 # NumberOfRelocations
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.word 0 # NumberOfLineNumbers
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.long 0x60500020 # Characteristics (section flags)
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#endif /* CONFIG_EFI_STUB */
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# Kernel attributes; used by setup. This is part 1 of the
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# header, from the old boot sector.
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.section ".header", "a"
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.globl hdr
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hdr:
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setup_sects: .byte 0 /* Filled in by build.c */
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root_flags: .word ROOT_RDONLY
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syssize: .long 0 /* Filled in by build.c */
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ram_size: .word 0 /* Obsolete */
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vid_mode: .word SVGA_MODE
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root_dev: .word 0 /* Filled in by build.c */
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boot_flag: .word 0xAA55
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# offset 512, entry point
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.globl _start
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_start:
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# Explicitly enter this as bytes, or the assembler
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# tries to generate a 3-byte jump here, which causes
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# everything else to push off to the wrong offset.
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.byte 0xeb # short (2-byte) jump
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.byte start_of_setup-1f
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1:
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# Part 2 of the header, from the old setup.S
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.ascii "HdrS" # header signature
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.word 0x020b # header version number (>= 0x0105)
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# or else old loadlin-1.5 will fail)
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.globl realmode_swtch
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realmode_swtch: .word 0, 0 # default_switch, SETUPSEG
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start_sys_seg: .word SYSSEG # obsolete and meaningless, but just
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# in case something decided to "use" it
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.word kernel_version-512 # pointing to kernel version string
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# above section of header is compatible
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# with loadlin-1.5 (header v1.5). Don't
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# change it.
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type_of_loader: .byte 0 # 0 means ancient bootloader, newer
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# bootloaders know to change this.
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# See Documentation/x86/boot.txt for
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# assigned ids
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# flags, unused bits must be zero (RFU) bit within loadflags
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loadflags:
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LOADED_HIGH = 1 # If set, the kernel is loaded high
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CAN_USE_HEAP = 0x80 # If set, the loader also has set
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# heap_end_ptr to tell how much
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# space behind setup.S can be used for
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# heap purposes.
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# Only the loader knows what is free
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.byte LOADED_HIGH
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setup_move_size: .word 0x8000 # size to move, when setup is not
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# loaded at 0x90000. We will move setup
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# to 0x90000 then just before jumping
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# into the kernel. However, only the
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# loader knows how much data behind
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# us also needs to be loaded.
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code32_start: # here loaders can put a different
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# start address for 32-bit code.
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.long 0x100000 # 0x100000 = default for big kernel
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ramdisk_image: .long 0 # address of loaded ramdisk image
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# Here the loader puts the 32-bit
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# address where it loaded the image.
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# This only will be read by the kernel.
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ramdisk_size: .long 0 # its size in bytes
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bootsect_kludge:
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.long 0 # obsolete
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heap_end_ptr: .word _end+STACK_SIZE-512
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# (Header version 0x0201 or later)
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# space from here (exclusive) down to
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# end of setup code can be used by setup
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# for local heap purposes.
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ext_loader_ver:
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.byte 0 # Extended boot loader version
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ext_loader_type:
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.byte 0 # Extended boot loader type
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cmd_line_ptr: .long 0 # (Header version 0x0202 or later)
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# If nonzero, a 32-bit pointer
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# to the kernel command line.
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# The command line should be
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# located between the start of
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# setup and the end of low
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# memory (0xa0000), or it may
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# get overwritten before it
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# gets read. If this field is
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# used, there is no longer
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# anything magical about the
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# 0x90000 segment; the setup
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# can be located anywhere in
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# low memory 0x10000 or higher.
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ramdisk_max: .long 0x7fffffff
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# (Header version 0x0203 or later)
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# The highest safe address for
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# the contents of an initrd
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# The current kernel allows up to 4 GB,
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# but leave it at 2 GB to avoid
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# possible bootloader bugs.
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kernel_alignment: .long CONFIG_PHYSICAL_ALIGN #physical addr alignment
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#required for protected mode
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#kernel
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#ifdef CONFIG_RELOCATABLE
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relocatable_kernel: .byte 1
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#else
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relocatable_kernel: .byte 0
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#endif
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min_alignment: .byte MIN_KERNEL_ALIGN_LG2 # minimum alignment
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pad3: .word 0
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cmdline_size: .long COMMAND_LINE_SIZE-1 #length of the command line,
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#added with boot protocol
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#version 2.06
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hardware_subarch: .long 0 # subarchitecture, added with 2.07
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# default to 0 for normal x86 PC
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hardware_subarch_data: .quad 0
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payload_offset: .long ZO_input_data
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payload_length: .long ZO_z_input_len
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setup_data: .quad 0 # 64-bit physical pointer to
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# single linked list of
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# struct setup_data
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pref_address: .quad LOAD_PHYSICAL_ADDR # preferred load addr
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#define ZO_INIT_SIZE (ZO__end - ZO_startup_32 + ZO_z_extract_offset)
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#define VO_INIT_SIZE (VO__end - VO__text)
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#if ZO_INIT_SIZE > VO_INIT_SIZE
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#define INIT_SIZE ZO_INIT_SIZE
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#else
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#define INIT_SIZE VO_INIT_SIZE
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#endif
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init_size: .long INIT_SIZE # kernel initialization size
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handover_offset: .long 0x30 # offset to the handover
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# protocol entry point
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# End of setup header #####################################################
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.section ".entrytext", "ax"
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start_of_setup:
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# Force %es = %ds
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movw %ds, %ax
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movw %ax, %es
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cld
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# Apparently some ancient versions of LILO invoked the kernel with %ss != %ds,
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# which happened to work by accident for the old code. Recalculate the stack
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# pointer if %ss is invalid. Otherwise leave it alone, LOADLIN sets up the
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# stack behind its own code, so we can't blindly put it directly past the heap.
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movw %ss, %dx
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cmpw %ax, %dx # %ds == %ss?
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movw %sp, %dx
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je 2f # -> assume %sp is reasonably set
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# Invalid %ss, make up a new stack
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movw $_end, %dx
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testb $CAN_USE_HEAP, loadflags
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jz 1f
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movw heap_end_ptr, %dx
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1: addw $STACK_SIZE, %dx
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jnc 2f
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xorw %dx, %dx # Prevent wraparound
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2: # Now %dx should point to the end of our stack space
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andw $~3, %dx # dword align (might as well...)
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jnz 3f
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movw $0xfffc, %dx # Make sure we're not zero
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3: movw %ax, %ss
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movzwl %dx, %esp # Clear upper half of %esp
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sti # Now we should have a working stack
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# We will have entered with %cs = %ds+0x20, normalize %cs so
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# it is on par with the other segments.
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pushw %ds
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pushw $6f
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lretw
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6:
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# Check signature at end of setup
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cmpl $0x5a5aaa55, setup_sig
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jne setup_bad
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# Zero the bss
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movw $__bss_start, %di
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movw $_end+3, %cx
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xorl %eax, %eax
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subw %di, %cx
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shrw $2, %cx
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rep; stosl
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# Jump to C code (should not return)
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calll main
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# Setup corrupt somehow...
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setup_bad:
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movl $setup_corrupt, %eax
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calll puts
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# Fall through...
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.globl die
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.type die, @function
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die:
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hlt
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jmp die
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.size die, .-die
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.section ".initdata", "a"
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setup_corrupt:
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.byte 7
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.string "No setup signature found...\n"
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.data
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dummy: .long 0
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