1b2441318SGreg Kroah-Hartman/* SPDX-License-Identifier: GPL-2.0 */ 296ae6ea0SThomas Gleixner/* 396ae6ea0SThomas Gleixner * header.S 496ae6ea0SThomas Gleixner * 596ae6ea0SThomas Gleixner * Copyright (C) 1991, 1992 Linus Torvalds 696ae6ea0SThomas Gleixner * 796ae6ea0SThomas Gleixner * Based on bootsect.S and setup.S 896ae6ea0SThomas Gleixner * modified by more people than can be counted 996ae6ea0SThomas Gleixner * 1096ae6ea0SThomas Gleixner * Rewritten as a common file by H. Peter Anvin (Apr 2007) 1196ae6ea0SThomas Gleixner * 1296ae6ea0SThomas Gleixner * BIG FAT NOTE: We're in real mode using 64k segments. Therefore segment 1396ae6ea0SThomas Gleixner * addresses must be multiplied by 16 to obtain their respective linear 1496ae6ea0SThomas Gleixner * addresses. To avoid confusion, linear addresses are written using leading 1596ae6ea0SThomas Gleixner * hex while segment addresses are written as segment:offset. 1696ae6ea0SThomas Gleixner * 1796ae6ea0SThomas Gleixner */ 18a3326a0dSArd Biesheuvel#include <linux/pe.h> 1996ae6ea0SThomas Gleixner#include <asm/segment.h> 2096ae6ea0SThomas Gleixner#include <asm/boot.h> 210341c14dSJeremy Fitzhardinge#include <asm/page_types.h> 2296ae6ea0SThomas Gleixner#include <asm/setup.h> 2309c205afSH. Peter Anvin#include <asm/bootparam.h> 2496ae6ea0SThomas Gleixner#include "boot.h" 2577d1a499SH. Peter Anvin#include "voffset.h" 2677d1a499SH. Peter Anvin#include "zoffset.h" 2796ae6ea0SThomas Gleixner 2896ae6ea0SThomas GleixnerBOOTSEG = 0x07C0 /* original address of boot-sector */ 295e47c478SH. Peter AnvinSYSSEG = 0x1000 /* historical load address >> 4 */ 3096ae6ea0SThomas Gleixner 3196ae6ea0SThomas Gleixner#ifndef SVGA_MODE 3296ae6ea0SThomas Gleixner#define SVGA_MODE ASK_VGA 3396ae6ea0SThomas Gleixner#endif 3496ae6ea0SThomas Gleixner 3596ae6ea0SThomas Gleixner#ifndef ROOT_RDONLY 3696ae6ea0SThomas Gleixner#define ROOT_RDONLY 1 3796ae6ea0SThomas Gleixner#endif 3896ae6ea0SThomas Gleixner 3996ae6ea0SThomas Gleixner .code16 4096ae6ea0SThomas Gleixner .section ".bstext", "ax" 41291f3632SMatt Fleming#ifdef CONFIG_EFI_STUB 42291f3632SMatt Fleming # "MZ", MS-DOS header 43a3326a0dSArd Biesheuvel .word MZ_MAGIC 4429636a5cSArd Biesheuvel .org 0x38 45291f3632SMatt Fleming # 46291f3632SMatt Fleming # Offset to the PE header. 47291f3632SMatt Fleming # 4829636a5cSArd Biesheuvel .long LINUX_PE_MAGIC 49291f3632SMatt Fleming .long pe_header 50291f3632SMatt Flemingpe_header: 51a3326a0dSArd Biesheuvel .long PE_MAGIC 52291f3632SMatt Fleming 53291f3632SMatt Flemingcoff_header: 54291f3632SMatt Fleming#ifdef CONFIG_X86_32 55a3326a0dSArd Biesheuvel .set image_file_add_flags, IMAGE_FILE_32BIT_MACHINE 56a3326a0dSArd Biesheuvel .set pe_opt_magic, PE_OPT_MAGIC_PE32 57a3326a0dSArd Biesheuvel .word IMAGE_FILE_MACHINE_I386 58291f3632SMatt Fleming#else 59a3326a0dSArd Biesheuvel .set image_file_add_flags, 0 60a3326a0dSArd Biesheuvel .set pe_opt_magic, PE_OPT_MAGIC_PE32PLUS 61a3326a0dSArd Biesheuvel .word IMAGE_FILE_MACHINE_AMD64 62291f3632SMatt Fleming#endif 6397aa2765SArd Biesheuvel .word section_count # nr_sections 64291f3632SMatt Fleming .long 0 # TimeDateStamp 65291f3632SMatt Fleming .long 0 # PointerToSymbolTable 66291f3632SMatt Fleming .long 1 # NumberOfSymbols 67291f3632SMatt Fleming .word section_table - optional_header # SizeOfOptionalHeader 68a3326a0dSArd Biesheuvel .word IMAGE_FILE_EXECUTABLE_IMAGE | \ 69a3326a0dSArd Biesheuvel image_file_add_flags | \ 70a3326a0dSArd Biesheuvel IMAGE_FILE_DEBUG_STRIPPED | \ 71a3326a0dSArd Biesheuvel IMAGE_FILE_LINE_NUMS_STRIPPED # Characteristics 72291f3632SMatt Fleming 73291f3632SMatt Flemingoptional_header: 74a3326a0dSArd Biesheuvel .word pe_opt_magic 75291f3632SMatt Fleming .byte 0x02 # MajorLinkerVersion 76291f3632SMatt Fleming .byte 0x14 # MinorLinkerVersion 77291f3632SMatt Fleming 78291f3632SMatt Fleming # Filled in by build.c 79291f3632SMatt Fleming .long 0 # SizeOfCode 80291f3632SMatt Fleming 81291f3632SMatt Fleming .long 0 # SizeOfInitializedData 82291f3632SMatt Fleming .long 0 # SizeOfUninitializedData 83291f3632SMatt Fleming 84291f3632SMatt Fleming # Filled in by build.c 85291f3632SMatt Fleming .long 0x0000 # AddressOfEntryPoint 86291f3632SMatt Fleming 87e31be363SMatt Fleming .long 0x0200 # BaseOfCode 88291f3632SMatt Fleming#ifdef CONFIG_X86_32 89291f3632SMatt Fleming .long 0 # data 90291f3632SMatt Fleming#endif 91291f3632SMatt Fleming 92291f3632SMatt Flemingextra_header_fields: 93291f3632SMatt Fleming#ifdef CONFIG_X86_32 944bac079dSArd Biesheuvel .long 0 # ImageBase 95291f3632SMatt Fleming#else 964bac079dSArd Biesheuvel .quad 0 # ImageBase 97291f3632SMatt Fleming#endif 98fa5c3501SMatt Fleming .long 0x20 # SectionAlignment 99743628e8SJordan Justen .long 0x20 # FileAlignment 100291f3632SMatt Fleming .word 0 # MajorOperatingSystemVersion 101291f3632SMatt Fleming .word 0 # MinorOperatingSystemVersion 102148d3f71SArd Biesheuvel .word LINUX_EFISTUB_MAJOR_VERSION # MajorImageVersion 103148d3f71SArd Biesheuvel .word LINUX_EFISTUB_MINOR_VERSION # MinorImageVersion 104291f3632SMatt Fleming .word 0 # MajorSubsystemVersion 105291f3632SMatt Fleming .word 0 # MinorSubsystemVersion 106291f3632SMatt Fleming .long 0 # Win32VersionValue 107291f3632SMatt Fleming 108291f3632SMatt Fleming # 109291f3632SMatt Fleming # The size of the bzImage is written in tools/build.c 110291f3632SMatt Fleming # 111291f3632SMatt Fleming .long 0 # SizeOfImage 112291f3632SMatt Fleming 113291f3632SMatt Fleming .long 0x200 # SizeOfHeaders 114291f3632SMatt Fleming .long 0 # CheckSum 115a3326a0dSArd Biesheuvel .word IMAGE_SUBSYSTEM_EFI_APPLICATION # Subsystem (EFI application) 116ca209f8bSLukas Bulwahn#ifdef CONFIG_EFI_DXE_MEM_ATTRIBUTES 11724b72bb1SPeter Jones .word IMAGE_DLL_CHARACTERISTICS_NX_COMPAT # DllCharacteristics 11824b72bb1SPeter Jones#else 119291f3632SMatt Fleming .word 0 # DllCharacteristics 12024b72bb1SPeter Jones#endif 121291f3632SMatt Fleming#ifdef CONFIG_X86_32 122291f3632SMatt Fleming .long 0 # SizeOfStackReserve 123291f3632SMatt Fleming .long 0 # SizeOfStackCommit 124291f3632SMatt Fleming .long 0 # SizeOfHeapReserve 125291f3632SMatt Fleming .long 0 # SizeOfHeapCommit 126291f3632SMatt Fleming#else 127291f3632SMatt Fleming .quad 0 # SizeOfStackReserve 128291f3632SMatt Fleming .quad 0 # SizeOfStackCommit 129291f3632SMatt Fleming .quad 0 # SizeOfHeapReserve 130291f3632SMatt Fleming .quad 0 # SizeOfHeapCommit 131291f3632SMatt Fleming#endif 132291f3632SMatt Fleming .long 0 # LoaderFlags 133a3326a0dSArd Biesheuvel .long (section_table - .) / 8 # NumberOfRvaAndSizes 134291f3632SMatt Fleming 135291f3632SMatt Fleming .quad 0 # ExportTable 136291f3632SMatt Fleming .quad 0 # ImportTable 137291f3632SMatt Fleming .quad 0 # ResourceTable 138291f3632SMatt Fleming .quad 0 # ExceptionTable 139291f3632SMatt Fleming .quad 0 # CertificationTable 140291f3632SMatt Fleming .quad 0 # BaseRelocationTable 141291f3632SMatt Fleming 142291f3632SMatt Fleming # Section table 143291f3632SMatt Flemingsection_table: 144743628e8SJordan Justen # 145743628e8SJordan Justen # The offset & size fields are filled in by build.c. 146743628e8SJordan Justen # 147743628e8SJordan Justen .ascii ".setup" 148291f3632SMatt Fleming .byte 0 149291f3632SMatt Fleming .byte 0 150291f3632SMatt Fleming .long 0 151291f3632SMatt Fleming .long 0x0 # startup_{32,64} 152291f3632SMatt Fleming .long 0 # Size of initialized data 153291f3632SMatt Fleming # on disk 154291f3632SMatt Fleming .long 0x0 # startup_{32,64} 155291f3632SMatt Fleming .long 0 # PointerToRelocations 156291f3632SMatt Fleming .long 0 # PointerToLineNumbers 157291f3632SMatt Fleming .word 0 # NumberOfRelocations 158291f3632SMatt Fleming .word 0 # NumberOfLineNumbers 159a3326a0dSArd Biesheuvel .long IMAGE_SCN_CNT_CODE | \ 160a3326a0dSArd Biesheuvel IMAGE_SCN_MEM_READ | \ 161e17a8bf1SArd Biesheuvel IMAGE_SCN_MEM_EXECUTE # Characteristics 162291f3632SMatt Fleming 163291f3632SMatt Fleming # 164291f3632SMatt Fleming # The EFI application loader requires a relocation section 165743628e8SJordan Justen # because EFI applications must be relocatable. The .reloc 166743628e8SJordan Justen # offset & size fields are filled in by build.c. 167291f3632SMatt Fleming # 168291f3632SMatt Fleming .ascii ".reloc" 169291f3632SMatt Fleming .byte 0 170291f3632SMatt Fleming .byte 0 1712e064b1eSJordan Justen .long 0 1722e064b1eSJordan Justen .long 0 1732e064b1eSJordan Justen .long 0 # SizeOfRawData 1742e064b1eSJordan Justen .long 0 # PointerToRawData 175291f3632SMatt Fleming .long 0 # PointerToRelocations 176291f3632SMatt Fleming .long 0 # PointerToLineNumbers 177291f3632SMatt Fleming .word 0 # NumberOfRelocations 178291f3632SMatt Fleming .word 0 # NumberOfLineNumbers 179a3326a0dSArd Biesheuvel .long IMAGE_SCN_CNT_INITIALIZED_DATA | \ 180a3326a0dSArd Biesheuvel IMAGE_SCN_MEM_READ | \ 181e17a8bf1SArd Biesheuvel IMAGE_SCN_MEM_DISCARDABLE # Characteristics 182743628e8SJordan Justen 18397aa2765SArd Biesheuvel#ifdef CONFIG_EFI_MIXED 18497aa2765SArd Biesheuvel # 18597aa2765SArd Biesheuvel # The offset & size fields are filled in by build.c. 18697aa2765SArd Biesheuvel # 18797aa2765SArd Biesheuvel .asciz ".compat" 18897aa2765SArd Biesheuvel .long 0 18997aa2765SArd Biesheuvel .long 0x0 19097aa2765SArd Biesheuvel .long 0 # Size of initialized data 19197aa2765SArd Biesheuvel # on disk 19297aa2765SArd Biesheuvel .long 0x0 19397aa2765SArd Biesheuvel .long 0 # PointerToRelocations 19497aa2765SArd Biesheuvel .long 0 # PointerToLineNumbers 19597aa2765SArd Biesheuvel .word 0 # NumberOfRelocations 19697aa2765SArd Biesheuvel .word 0 # NumberOfLineNumbers 197a3326a0dSArd Biesheuvel .long IMAGE_SCN_CNT_INITIALIZED_DATA | \ 198a3326a0dSArd Biesheuvel IMAGE_SCN_MEM_READ | \ 199e17a8bf1SArd Biesheuvel IMAGE_SCN_MEM_DISCARDABLE # Characteristics 20097aa2765SArd Biesheuvel#endif 20197aa2765SArd Biesheuvel 202743628e8SJordan Justen # 203743628e8SJordan Justen # The offset & size fields are filled in by build.c. 204743628e8SJordan Justen # 205743628e8SJordan Justen .ascii ".text" 206743628e8SJordan Justen .byte 0 207743628e8SJordan Justen .byte 0 208743628e8SJordan Justen .byte 0 209743628e8SJordan Justen .long 0 210743628e8SJordan Justen .long 0x0 # startup_{32,64} 211743628e8SJordan Justen .long 0 # Size of initialized data 212743628e8SJordan Justen # on disk 213743628e8SJordan Justen .long 0x0 # startup_{32,64} 214743628e8SJordan Justen .long 0 # PointerToRelocations 215743628e8SJordan Justen .long 0 # PointerToLineNumbers 216743628e8SJordan Justen .word 0 # NumberOfRelocations 217743628e8SJordan Justen .word 0 # NumberOfLineNumbers 218a3326a0dSArd Biesheuvel .long IMAGE_SCN_CNT_CODE | \ 219a3326a0dSArd Biesheuvel IMAGE_SCN_MEM_READ | \ 220e17a8bf1SArd Biesheuvel IMAGE_SCN_MEM_EXECUTE # Characteristics 221743628e8SJordan Justen 22297aa2765SArd Biesheuvel .set section_count, (. - section_table) / 40 223291f3632SMatt Fleming#endif /* CONFIG_EFI_STUB */ 22496ae6ea0SThomas Gleixner 22596ae6ea0SThomas Gleixner # Kernel attributes; used by setup. This is part 1 of the 22696ae6ea0SThomas Gleixner # header, from the old boot sector. 22796ae6ea0SThomas Gleixner 22896ae6ea0SThomas Gleixner .section ".header", "a" 22909c205afSH. Peter Anvin .globl sentinel 23009c205afSH. Peter Anvinsentinel: .byte 0xff, 0xff /* Used to detect broken loaders */ 23109c205afSH. Peter Anvin 23296ae6ea0SThomas Gleixner .globl hdr 23396ae6ea0SThomas Gleixnerhdr: 2345e47c478SH. Peter Anvinsetup_sects: .byte 0 /* Filled in by build.c */ 23596ae6ea0SThomas Gleixnerroot_flags: .word ROOT_RDONLY 2365e47c478SH. Peter Anvinsyssize: .long 0 /* Filled in by build.c */ 2375e47c478SH. Peter Anvinram_size: .word 0 /* Obsolete */ 23896ae6ea0SThomas Gleixnervid_mode: .word SVGA_MODE 23908796fc9SArd Biesheuvelroot_dev: .word 0 /* Default to major/minor 0/0 */ 24096ae6ea0SThomas Gleixnerboot_flag: .word 0xAA55 24196ae6ea0SThomas Gleixner 24296ae6ea0SThomas Gleixner # offset 512, entry point 24396ae6ea0SThomas Gleixner 24496ae6ea0SThomas Gleixner .globl _start 24596ae6ea0SThomas Gleixner_start: 24696ae6ea0SThomas Gleixner # Explicitly enter this as bytes, or the assembler 24796ae6ea0SThomas Gleixner # tries to generate a 3-byte jump here, which causes 24896ae6ea0SThomas Gleixner # everything else to push off to the wrong offset. 24996ae6ea0SThomas Gleixner .byte 0xeb # short (2-byte) jump 25096ae6ea0SThomas Gleixner .byte start_of_setup-1f 25196ae6ea0SThomas Gleixner1: 25296ae6ea0SThomas Gleixner 25396ae6ea0SThomas Gleixner # Part 2 of the header, from the old setup.S 25496ae6ea0SThomas Gleixner 25596ae6ea0SThomas Gleixner .ascii "HdrS" # header signature 256b3c72fc9SDaniel Kiper .word 0x020f # header version number (>= 0x0105) 25796ae6ea0SThomas Gleixner # or else old loadlin-1.5 will fail) 25896ae6ea0SThomas Gleixner .globl realmode_swtch 25996ae6ea0SThomas Gleixnerrealmode_swtch: .word 0, 0 # default_switch, SETUPSEG 2605e47c478SH. Peter Anvinstart_sys_seg: .word SYSSEG # obsolete and meaningless, but just 2615e47c478SH. Peter Anvin # in case something decided to "use" it 26296ae6ea0SThomas Gleixner .word kernel_version-512 # pointing to kernel version string 26396ae6ea0SThomas Gleixner # above section of header is compatible 26496ae6ea0SThomas Gleixner # with loadlin-1.5 (header v1.5). Don't 26596ae6ea0SThomas Gleixner # change it. 26696ae6ea0SThomas Gleixner 2675e47c478SH. Peter Anvintype_of_loader: .byte 0 # 0 means ancient bootloader, newer 2685e47c478SH. Peter Anvin # bootloaders know to change this. 269ff61f079SJonathan Corbet # See Documentation/arch/x86/boot.rst for 27096ae6ea0SThomas Gleixner # assigned ids 27196ae6ea0SThomas Gleixner 27296ae6ea0SThomas Gleixner# flags, unused bits must be zero (RFU) bit within loadflags 27396ae6ea0SThomas Gleixnerloadflags: 27409c205afSH. Peter Anvin .byte LOADED_HIGH # The kernel is to be loaded high 27596ae6ea0SThomas Gleixner 27696ae6ea0SThomas Gleixnersetup_move_size: .word 0x8000 # size to move, when setup is not 27796ae6ea0SThomas Gleixner # loaded at 0x90000. We will move setup 27896ae6ea0SThomas Gleixner # to 0x90000 then just before jumping 27996ae6ea0SThomas Gleixner # into the kernel. However, only the 28096ae6ea0SThomas Gleixner # loader knows how much data behind 28196ae6ea0SThomas Gleixner # us also needs to be loaded. 28296ae6ea0SThomas Gleixner 28396ae6ea0SThomas Gleixnercode32_start: # here loaders can put a different 28496ae6ea0SThomas Gleixner # start address for 32-bit code. 28596ae6ea0SThomas Gleixner .long 0x100000 # 0x100000 = default for big kernel 28696ae6ea0SThomas Gleixner 28796ae6ea0SThomas Gleixnerramdisk_image: .long 0 # address of loaded ramdisk image 28896ae6ea0SThomas Gleixner # Here the loader puts the 32-bit 28996ae6ea0SThomas Gleixner # address where it loaded the image. 29096ae6ea0SThomas Gleixner # This only will be read by the kernel. 29196ae6ea0SThomas Gleixner 29296ae6ea0SThomas Gleixnerramdisk_size: .long 0 # its size in bytes 29396ae6ea0SThomas Gleixner 29496ae6ea0SThomas Gleixnerbootsect_kludge: 29596ae6ea0SThomas Gleixner .long 0 # obsolete 29696ae6ea0SThomas Gleixner 2976b6815c6SH. Peter Anvinheap_end_ptr: .word _end+STACK_SIZE-512 2986b6815c6SH. Peter Anvin # (Header version 0x0201 or later) 29996ae6ea0SThomas Gleixner # space from here (exclusive) down to 30096ae6ea0SThomas Gleixner # end of setup code can be used by setup 30196ae6ea0SThomas Gleixner # for local heap purposes. 30296ae6ea0SThomas Gleixner 3035031296cSH. Peter Anvinext_loader_ver: 3045031296cSH. Peter Anvin .byte 0 # Extended boot loader version 3055031296cSH. Peter Anvinext_loader_type: 3065031296cSH. Peter Anvin .byte 0 # Extended boot loader type 3075031296cSH. Peter Anvin 30896ae6ea0SThomas Gleixnercmd_line_ptr: .long 0 # (Header version 0x0202 or later) 30996ae6ea0SThomas Gleixner # If nonzero, a 32-bit pointer 31096ae6ea0SThomas Gleixner # to the kernel command line. 31196ae6ea0SThomas Gleixner # The command line should be 31296ae6ea0SThomas Gleixner # located between the start of 31396ae6ea0SThomas Gleixner # setup and the end of low 31496ae6ea0SThomas Gleixner # memory (0xa0000), or it may 31596ae6ea0SThomas Gleixner # get overwritten before it 31696ae6ea0SThomas Gleixner # gets read. If this field is 31796ae6ea0SThomas Gleixner # used, there is no longer 31896ae6ea0SThomas Gleixner # anything magical about the 31996ae6ea0SThomas Gleixner # 0x90000 segment; the setup 32096ae6ea0SThomas Gleixner # can be located anywhere in 32196ae6ea0SThomas Gleixner # low memory 0x10000 or higher. 32296ae6ea0SThomas Gleixner 3233e920b53SBorislav Petkovinitrd_addr_max: .long 0x7fffffff 32496ae6ea0SThomas Gleixner # (Header version 0x0203 or later) 32596ae6ea0SThomas Gleixner # The highest safe address for 32696ae6ea0SThomas Gleixner # the contents of an initrd 327cf8fa920SH. Peter Anvin # The current kernel allows up to 4 GB, 328cf8fa920SH. Peter Anvin # but leave it at 2 GB to avoid 329cf8fa920SH. Peter Anvin # possible bootloader bugs. 33096ae6ea0SThomas Gleixner 33196ae6ea0SThomas Gleixnerkernel_alignment: .long CONFIG_PHYSICAL_ALIGN #physical addr alignment 33296ae6ea0SThomas Gleixner #required for protected mode 33396ae6ea0SThomas Gleixner #kernel 33496ae6ea0SThomas Gleixner#ifdef CONFIG_RELOCATABLE 33596ae6ea0SThomas Gleixnerrelocatable_kernel: .byte 1 33696ae6ea0SThomas Gleixner#else 33796ae6ea0SThomas Gleixnerrelocatable_kernel: .byte 0 33896ae6ea0SThomas Gleixner#endif 33937ba7ab5SH. Peter Anvinmin_alignment: .byte MIN_KERNEL_ALIGN_LG2 # minimum alignment 34009c205afSH. Peter Anvin 34109c205afSH. Peter Anvinxloadflags: 34209c205afSH. Peter Anvin#ifdef CONFIG_X86_64 34309c205afSH. Peter Anvin# define XLF0 XLF_KERNEL_64 /* 64-bit kernel */ 34409c205afSH. Peter Anvin#else 34509c205afSH. Peter Anvin# define XLF0 0 34609c205afSH. Peter Anvin#endif 347ee92d815SYinghai Lu 348745c5167SMatt Fleming#if defined(CONFIG_RELOCATABLE) && defined(CONFIG_X86_64) 349ee92d815SYinghai Lu /* kernel/boot_param/ramdisk could be loaded above 4g */ 350ee92d815SYinghai Lu# define XLF1 XLF_CAN_BE_LOADED_ABOVE_4G 351ee92d815SYinghai Lu#else 352ee92d815SYinghai Lu# define XLF1 0 353ee92d815SYinghai Lu#endif 354ee92d815SYinghai Lu 355cc3fdda2SArd Biesheuvel#ifdef CONFIG_EFI_HANDOVER_PROTOCOL 3567d453eeeSMatt Fleming# ifdef CONFIG_EFI_MIXED 3577d453eeeSMatt Fleming# define XLF23 (XLF_EFI_HANDOVER_32|XLF_EFI_HANDOVER_64) 3587d453eeeSMatt Fleming# else 35909c205afSH. Peter Anvin# ifdef CONFIG_X86_64 36009c205afSH. Peter Anvin# define XLF23 XLF_EFI_HANDOVER_64 /* 64-bit EFI handover ok */ 36109c205afSH. Peter Anvin# else 36209c205afSH. Peter Anvin# define XLF23 XLF_EFI_HANDOVER_32 /* 32-bit EFI handover ok */ 36309c205afSH. Peter Anvin# endif 3647d453eeeSMatt Fleming# endif 36509c205afSH. Peter Anvin#else 36609c205afSH. Peter Anvin# define XLF23 0 36709c205afSH. Peter Anvin#endif 368456a29ddSDave Young 3692965faa5SDave Young#if defined(CONFIG_X86_64) && defined(CONFIG_EFI) && defined(CONFIG_KEXEC_CORE) 370456a29ddSDave Young# define XLF4 XLF_EFI_KEXEC 371456a29ddSDave Young#else 372456a29ddSDave Young# define XLF4 0 373456a29ddSDave Young#endif 374456a29ddSDave Young 375f2d08c5dSBaoquan He#ifdef CONFIG_X86_64 376f2d08c5dSBaoquan He#ifdef CONFIG_X86_5LEVEL 377f2d08c5dSBaoquan He#define XLF56 (XLF_5LEVEL|XLF_5LEVEL_ENABLED) 378f2d08c5dSBaoquan He#else 379f2d08c5dSBaoquan He#define XLF56 XLF_5LEVEL 380f2d08c5dSBaoquan He#endif 381f2d08c5dSBaoquan He#else 382f2d08c5dSBaoquan He#define XLF56 0 383f2d08c5dSBaoquan He#endif 384f2d08c5dSBaoquan He 385f2d08c5dSBaoquan He .word XLF0 | XLF1 | XLF23 | XLF4 | XLF56 38696ae6ea0SThomas Gleixner 38796ae6ea0SThomas Gleixnercmdline_size: .long COMMAND_LINE_SIZE-1 #length of the command line, 38896ae6ea0SThomas Gleixner #added with boot protocol 38996ae6ea0SThomas Gleixner #version 2.06 39096ae6ea0SThomas Gleixner 391a24e7851SRusty Russellhardware_subarch: .long 0 # subarchitecture, added with 2.07 392a24e7851SRusty Russell # default to 0 for normal x86 PC 393a24e7851SRusty Russell 394a24e7851SRusty Russellhardware_subarch_data: .quad 0 395a24e7851SRusty Russell 39677d1a499SH. Peter Anvinpayload_offset: .long ZO_input_data 39777d1a499SH. Peter Anvinpayload_length: .long ZO_z_input_len 398099e1377SIan Campbell 3998b664aa6SHuang, Yingsetup_data: .quad 0 # 64-bit physical pointer to 4008b664aa6SHuang, Ying # single linked list of 4018b664aa6SHuang, Ying # struct setup_data 4028b664aa6SHuang, Ying 40337ba7ab5SH. Peter Anvinpref_address: .quad LOAD_PHYSICAL_ADDR # preferred load addr 40437ba7ab5SH. Peter Anvin 4054252db10SBaoquan He# 4064252db10SBaoquan He# Getting to provably safe in-place decompression is hard. Worst case 4074252db10SBaoquan He# behaviours need to be analyzed. Here let's take the decompression of 4084252db10SBaoquan He# a gzip-compressed kernel as example, to illustrate it: 4094252db10SBaoquan He# 4104252db10SBaoquan He# The file layout of gzip compressed kernel is: 4114252db10SBaoquan He# 4124252db10SBaoquan He# magic[2] 4134252db10SBaoquan He# method[1] 4144252db10SBaoquan He# flags[1] 4154252db10SBaoquan He# timestamp[4] 4164252db10SBaoquan He# extraflags[1] 4174252db10SBaoquan He# os[1] 4184252db10SBaoquan He# compressed data blocks[N] 4194252db10SBaoquan He# crc[4] orig_len[4] 4204252db10SBaoquan He# 4214252db10SBaoquan He# ... resulting in +18 bytes overhead of uncompressed data. 4224252db10SBaoquan He# 4234252db10SBaoquan He# (For more information, please refer to RFC 1951 and RFC 1952.) 4244252db10SBaoquan He# 4254252db10SBaoquan He# Files divided into blocks 4264252db10SBaoquan He# 1 bit (last block flag) 4274252db10SBaoquan He# 2 bits (block type) 4284252db10SBaoquan He# 4294252db10SBaoquan He# 1 block occurs every 32K -1 bytes or when there 50% compression 4304252db10SBaoquan He# has been achieved. The smallest block type encoding is always used. 4314252db10SBaoquan He# 4324252db10SBaoquan He# stored: 4334252db10SBaoquan He# 32 bits length in bytes. 4344252db10SBaoquan He# 4354252db10SBaoquan He# fixed: 4364252db10SBaoquan He# magic fixed tree. 4374252db10SBaoquan He# symbols. 4384252db10SBaoquan He# 4394252db10SBaoquan He# dynamic: 4404252db10SBaoquan He# dynamic tree encoding. 4414252db10SBaoquan He# symbols. 4424252db10SBaoquan He# 4434252db10SBaoquan He# 4444252db10SBaoquan He# The buffer for decompression in place is the length of the uncompressed 4454252db10SBaoquan He# data, plus a small amount extra to keep the algorithm safe. The 4464252db10SBaoquan He# compressed data is placed at the end of the buffer. The output pointer 4474252db10SBaoquan He# is placed at the start of the buffer and the input pointer is placed 4484252db10SBaoquan He# where the compressed data starts. Problems will occur when the output 4494252db10SBaoquan He# pointer overruns the input pointer. 4504252db10SBaoquan He# 4514252db10SBaoquan He# The output pointer can only overrun the input pointer if the input 4524252db10SBaoquan He# pointer is moving faster than the output pointer. A condition only 4534252db10SBaoquan He# triggered by data whose compressed form is larger than the uncompressed 4544252db10SBaoquan He# form. 4554252db10SBaoquan He# 4564252db10SBaoquan He# The worst case at the block level is a growth of the compressed data 4574252db10SBaoquan He# of 5 bytes per 32767 bytes. 4584252db10SBaoquan He# 4594252db10SBaoquan He# The worst case internal to a compressed block is very hard to figure. 4604252db10SBaoquan He# The worst case can at least be bounded by having one bit that represents 4614252db10SBaoquan He# 32764 bytes and then all of the rest of the bytes representing the very 4624252db10SBaoquan He# very last byte. 4634252db10SBaoquan He# 4644252db10SBaoquan He# All of which is enough to compute an amount of extra data that is required 4654252db10SBaoquan He# to be safe. To avoid problems at the block level allocating 5 extra bytes 4664252db10SBaoquan He# per 32767 bytes of data is sufficient. To avoid problems internal to a 4674252db10SBaoquan He# block adding an extra 32767 bytes (the worst case uncompressed block size) 4684252db10SBaoquan He# is sufficient, to ensure that in the worst case the decompressed data for 4694252db10SBaoquan He# block will stop the byte before the compressed data for a block begins. 4704252db10SBaoquan He# To avoid problems with the compressed data's meta information an extra 18 4714252db10SBaoquan He# bytes are needed. Leading to the formula: 4724252db10SBaoquan He# 473d607251bSYinghai Lu# extra_bytes = (uncompressed_size >> 12) + 32768 + 18 4744252db10SBaoquan He# 4754252db10SBaoquan He# Adding 8 bytes per 32K is a bit excessive but much easier to calculate. 4764252db10SBaoquan He# Adding 32768 instead of 32767 just makes for round numbers. 4774252db10SBaoquan He# 4784252db10SBaoquan He# Above analysis is for decompressing gzip compressed kernel only. Up to 4794252db10SBaoquan He# now 6 different decompressor are supported all together. And among them 4804252db10SBaoquan He# xz stores data in chunks and has maximum chunk of 64K. Hence safety 4814252db10SBaoquan He# margin should be updated to cover all decompressors so that we don't 4824252db10SBaoquan He# need to deal with each of them separately. Please check 4834252db10SBaoquan He# the description in lib/decompressor_xxx.c for specific information. 4844252db10SBaoquan He# 4854252db10SBaoquan He# extra_bytes = (uncompressed_size >> 12) + 65536 + 128 4865746f055SJan H. Schönherr# 4875746f055SJan H. Schönherr# LZ4 is even worse: data that cannot be further compressed grows by 0.4%, 4885746f055SJan H. Schönherr# or one byte per 256 bytes. OTOH, we can safely get rid of the +128 as 4895746f055SJan H. Schönherr# the size-dependent part now grows so fast. 4905746f055SJan H. Schönherr# 4915746f055SJan H. Schönherr# extra_bytes = (uncompressed_size >> 8) + 65536 4920fe4f4efSNick Terrell# 4930fe4f4efSNick Terrell# ZSTD compressed data grows by at most 3 bytes per 128K, and only has a 22 4940fe4f4efSNick Terrell# byte fixed overhead but has a maximum block size of 128K, so it needs a 4950fe4f4efSNick Terrell# larger margin. 4960fe4f4efSNick Terrell# 4970fe4f4efSNick Terrell# extra_bytes = (uncompressed_size >> 8) + 131072 4984252db10SBaoquan He 4990fe4f4efSNick Terrell#define ZO_z_extra_bytes ((ZO_z_output_len >> 8) + 131072) 500d607251bSYinghai Lu#if ZO_z_output_len > ZO_z_input_len 501d607251bSYinghai Lu# define ZO_z_extract_offset (ZO_z_output_len + ZO_z_extra_bytes - \ 502d607251bSYinghai Lu ZO_z_input_len) 503d607251bSYinghai Lu#else 504d607251bSYinghai Lu# define ZO_z_extract_offset ZO_z_extra_bytes 505d607251bSYinghai Lu#endif 506d607251bSYinghai Lu 507d607251bSYinghai Lu/* 508d607251bSYinghai Lu * The extract_offset has to be bigger than ZO head section. Otherwise when 509d607251bSYinghai Lu * the head code is running to move ZO to the end of the buffer, it will 510d607251bSYinghai Lu * overwrite the head code itself. 511d607251bSYinghai Lu */ 512d607251bSYinghai Lu#if (ZO__ehead - ZO_startup_32) > ZO_z_extract_offset 513d607251bSYinghai Lu# define ZO_z_min_extract_offset ((ZO__ehead - ZO_startup_32 + 4095) & ~4095) 514d607251bSYinghai Lu#else 515d607251bSYinghai Lu# define ZO_z_min_extract_offset ((ZO_z_extract_offset + 4095) & ~4095) 516d607251bSYinghai Lu#endif 517d607251bSYinghai Lu 518d607251bSYinghai Lu#define ZO_INIT_SIZE (ZO__end - ZO_startup_32 + ZO_z_min_extract_offset) 519d607251bSYinghai Lu 52037ba7ab5SH. Peter Anvin#define VO_INIT_SIZE (VO__end - VO__text) 52137ba7ab5SH. Peter Anvin#if ZO_INIT_SIZE > VO_INIT_SIZE 52237ba7ab5SH. Peter Anvin# define INIT_SIZE ZO_INIT_SIZE 52337ba7ab5SH. Peter Anvin#else 52437ba7ab5SH. Peter Anvin# define INIT_SIZE VO_INIT_SIZE 52537ba7ab5SH. Peter Anvin#endif 526d607251bSYinghai Lu 52737ba7ab5SH. Peter Anvininit_size: .long INIT_SIZE # kernel initialization size 52886134a1bSMatt Fleminghandover_offset: .long 0 # Filled in by build.c 529*8e102324SArd Biesheuvelkernel_info_offset: .long ZO_kernel_info 53037ba7ab5SH. Peter Anvin 53196ae6ea0SThomas Gleixner# End of setup header ##################################################### 53296ae6ea0SThomas Gleixner 5337a734e7dSH. Peter Anvin .section ".entrytext", "ax" 53496ae6ea0SThomas Gleixnerstart_of_setup: 53596ae6ea0SThomas Gleixner# Force %es = %ds 53696ae6ea0SThomas Gleixner movw %ds, %ax 53796ae6ea0SThomas Gleixner movw %ax, %es 53896ae6ea0SThomas Gleixner cld 53996ae6ea0SThomas Gleixner 54016252da6SJens Rottmann# Apparently some ancient versions of LILO invoked the kernel with %ss != %ds, 54116252da6SJens Rottmann# which happened to work by accident for the old code. Recalculate the stack 54216252da6SJens Rottmann# pointer if %ss is invalid. Otherwise leave it alone, LOADLIN sets up the 54316252da6SJens Rottmann# stack behind its own code, so we can't blindly put it directly past the heap. 5446b6815c6SH. Peter Anvin 5456b6815c6SH. Peter Anvin movw %ss, %dx 5466b6815c6SH. Peter Anvin cmpw %ax, %dx # %ds == %ss? 5476b6815c6SH. Peter Anvin movw %sp, %dx 54816252da6SJens Rottmann je 2f # -> assume %sp is reasonably set 5496b6815c6SH. Peter Anvin 55016252da6SJens Rottmann # Invalid %ss, make up a new stack 55116252da6SJens Rottmann movw $_end, %dx 55216252da6SJens Rottmann testb $CAN_USE_HEAP, loadflags 55316252da6SJens Rottmann jz 1f 55416252da6SJens Rottmann movw heap_end_ptr, %dx 55516252da6SJens Rottmann1: addw $STACK_SIZE, %dx 55616252da6SJens Rottmann jnc 2f 55716252da6SJens Rottmann xorw %dx, %dx # Prevent wraparound 55816252da6SJens Rottmann 55916252da6SJens Rottmann2: # Now %dx should point to the end of our stack space 5606b6815c6SH. Peter Anvin andw $~3, %dx # dword align (might as well...) 5616b6815c6SH. Peter Anvin jnz 3f 5626b6815c6SH. Peter Anvin movw $0xfffc, %dx # Make sure we're not zero 56316252da6SJens Rottmann3: movw %ax, %ss 5646b6815c6SH. Peter Anvin movzwl %dx, %esp # Clear upper half of %esp 5656b6815c6SH. Peter Anvin sti # Now we should have a working stack 5666b6815c6SH. Peter Anvin 5676b6815c6SH. Peter Anvin# We will have entered with %cs = %ds+0x20, normalize %cs so 5686b6815c6SH. Peter Anvin# it is on par with the other segments. 5696b6815c6SH. Peter Anvin pushw %ds 5706b6815c6SH. Peter Anvin pushw $6f 5716b6815c6SH. Peter Anvin lretw 5726b6815c6SH. Peter Anvin6: 57396ae6ea0SThomas Gleixner 57496ae6ea0SThomas Gleixner# Check signature at end of setup 57596ae6ea0SThomas Gleixner cmpl $0x5a5aaa55, setup_sig 57696ae6ea0SThomas Gleixner jne setup_bad 57796ae6ea0SThomas Gleixner 57896ae6ea0SThomas Gleixner# Zero the bss 57996ae6ea0SThomas Gleixner movw $__bss_start, %di 58096ae6ea0SThomas Gleixner movw $_end+3, %cx 58196ae6ea0SThomas Gleixner xorl %eax, %eax 58296ae6ea0SThomas Gleixner subw %di, %cx 58396ae6ea0SThomas Gleixner shrw $2, %cx 58496ae6ea0SThomas Gleixner rep; stosl 58596ae6ea0SThomas Gleixner 58696ae6ea0SThomas Gleixner# Jump to C code (should not return) 58796ae6ea0SThomas Gleixner calll main 58896ae6ea0SThomas Gleixner 58996ae6ea0SThomas Gleixner# Setup corrupt somehow... 59096ae6ea0SThomas Gleixnersetup_bad: 59196ae6ea0SThomas Gleixner movl $setup_corrupt, %eax 59296ae6ea0SThomas Gleixner calll puts 59396ae6ea0SThomas Gleixner # Fall through... 59496ae6ea0SThomas Gleixner 59596ae6ea0SThomas Gleixner .globl die 59696ae6ea0SThomas Gleixner .type die, @function 59796ae6ea0SThomas Gleixnerdie: 59896ae6ea0SThomas Gleixner hlt 59996ae6ea0SThomas Gleixner jmp die 60096ae6ea0SThomas Gleixner 60196ae6ea0SThomas Gleixner .size die, .-die 60296ae6ea0SThomas Gleixner 60396ae6ea0SThomas Gleixner .section ".initdata", "a" 60496ae6ea0SThomas Gleixnersetup_corrupt: 60596ae6ea0SThomas Gleixner .byte 7 60696ae6ea0SThomas Gleixner .string "No setup signature found...\n" 607