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" 4196ae6ea0SThomas Gleixner 4296ae6ea0SThomas Gleixner .global bootsect_start 4396ae6ea0SThomas Gleixnerbootsect_start: 44291f3632SMatt Fleming#ifdef CONFIG_EFI_STUB 45291f3632SMatt Fleming # "MZ", MS-DOS header 46a3326a0dSArd Biesheuvel .word MZ_MAGIC 47291f3632SMatt Fleming#endif 4896ae6ea0SThomas Gleixner 4996ae6ea0SThomas Gleixner # Normalize the start address 5096ae6ea0SThomas Gleixner ljmp $BOOTSEG, $start2 5196ae6ea0SThomas Gleixner 5296ae6ea0SThomas Gleixnerstart2: 5396ae6ea0SThomas Gleixner movw %cs, %ax 5496ae6ea0SThomas Gleixner movw %ax, %ds 5596ae6ea0SThomas Gleixner movw %ax, %es 5696ae6ea0SThomas Gleixner movw %ax, %ss 5796ae6ea0SThomas Gleixner xorw %sp, %sp 5896ae6ea0SThomas Gleixner sti 5996ae6ea0SThomas Gleixner cld 6096ae6ea0SThomas Gleixner 6196ae6ea0SThomas Gleixner movw $bugger_off_msg, %si 6296ae6ea0SThomas Gleixner 6396ae6ea0SThomas Gleixnermsg_loop: 6496ae6ea0SThomas Gleixner lodsb 6596ae6ea0SThomas Gleixner andb %al, %al 6696ae6ea0SThomas Gleixner jz bs_die 6796ae6ea0SThomas Gleixner movb $0xe, %ah 6896ae6ea0SThomas Gleixner movw $7, %bx 6996ae6ea0SThomas Gleixner int $0x10 7096ae6ea0SThomas Gleixner jmp msg_loop 7196ae6ea0SThomas Gleixner 7296ae6ea0SThomas Gleixnerbs_die: 7396ae6ea0SThomas Gleixner # Allow the user to press a key, then reboot 7496ae6ea0SThomas Gleixner xorw %ax, %ax 7596ae6ea0SThomas Gleixner int $0x16 7696ae6ea0SThomas Gleixner int $0x19 7796ae6ea0SThomas Gleixner 7896ae6ea0SThomas Gleixner # int 0x19 should never return. In case it does anyway, 7996ae6ea0SThomas Gleixner # invoke the BIOS reset code... 8096ae6ea0SThomas Gleixner ljmp $0xf000,$0xfff0 8196ae6ea0SThomas Gleixner 82291f3632SMatt Fleming#ifdef CONFIG_EFI_STUB 83291f3632SMatt Fleming .org 0x3c 84291f3632SMatt Fleming # 85291f3632SMatt Fleming # Offset to the PE header. 86291f3632SMatt Fleming # 87291f3632SMatt Fleming .long pe_header 88291f3632SMatt Fleming#endif /* CONFIG_EFI_STUB */ 89291f3632SMatt Fleming 9096ae6ea0SThomas Gleixner .section ".bsdata", "a" 9196ae6ea0SThomas Gleixnerbugger_off_msg: 92c7fb93ecSMichael Brown .ascii "Use a boot loader.\r\n" 9396ae6ea0SThomas Gleixner .ascii "\n" 9496ae6ea0SThomas Gleixner .ascii "Remove disk and press any key to reboot...\r\n" 9596ae6ea0SThomas Gleixner .byte 0 9696ae6ea0SThomas Gleixner 97291f3632SMatt Fleming#ifdef CONFIG_EFI_STUB 98291f3632SMatt Flemingpe_header: 99a3326a0dSArd Biesheuvel .long PE_MAGIC 100291f3632SMatt Fleming 101291f3632SMatt Flemingcoff_header: 102291f3632SMatt Fleming#ifdef CONFIG_X86_32 103a3326a0dSArd Biesheuvel .set image_file_add_flags, IMAGE_FILE_32BIT_MACHINE 104a3326a0dSArd Biesheuvel .set pe_opt_magic, PE_OPT_MAGIC_PE32 105a3326a0dSArd Biesheuvel .word IMAGE_FILE_MACHINE_I386 106291f3632SMatt Fleming#else 107a3326a0dSArd Biesheuvel .set image_file_add_flags, 0 108a3326a0dSArd Biesheuvel .set pe_opt_magic, PE_OPT_MAGIC_PE32PLUS 109a3326a0dSArd Biesheuvel .word IMAGE_FILE_MACHINE_AMD64 110291f3632SMatt Fleming#endif 11197aa2765SArd Biesheuvel .word section_count # nr_sections 112291f3632SMatt Fleming .long 0 # TimeDateStamp 113291f3632SMatt Fleming .long 0 # PointerToSymbolTable 114291f3632SMatt Fleming .long 1 # NumberOfSymbols 115291f3632SMatt Fleming .word section_table - optional_header # SizeOfOptionalHeader 116a3326a0dSArd Biesheuvel .word IMAGE_FILE_EXECUTABLE_IMAGE | \ 117a3326a0dSArd Biesheuvel image_file_add_flags | \ 118a3326a0dSArd Biesheuvel IMAGE_FILE_DEBUG_STRIPPED | \ 119a3326a0dSArd Biesheuvel IMAGE_FILE_LINE_NUMS_STRIPPED # Characteristics 120291f3632SMatt Fleming 121291f3632SMatt Flemingoptional_header: 122a3326a0dSArd Biesheuvel .word pe_opt_magic 123291f3632SMatt Fleming .byte 0x02 # MajorLinkerVersion 124291f3632SMatt Fleming .byte 0x14 # MinorLinkerVersion 125291f3632SMatt Fleming 126291f3632SMatt Fleming # Filled in by build.c 127291f3632SMatt Fleming .long 0 # SizeOfCode 128291f3632SMatt Fleming 129291f3632SMatt Fleming .long 0 # SizeOfInitializedData 130291f3632SMatt Fleming .long 0 # SizeOfUninitializedData 131291f3632SMatt Fleming 132291f3632SMatt Fleming # Filled in by build.c 133291f3632SMatt Fleming .long 0x0000 # AddressOfEntryPoint 134291f3632SMatt Fleming 135e31be363SMatt Fleming .long 0x0200 # BaseOfCode 136291f3632SMatt Fleming#ifdef CONFIG_X86_32 137291f3632SMatt Fleming .long 0 # data 138291f3632SMatt Fleming#endif 139291f3632SMatt Fleming 140291f3632SMatt Flemingextra_header_fields: 14126725192SArvind Sankar # PE specification requires ImageBase to be 64k aligned 14226725192SArvind Sankar .set image_base, (LOAD_PHYSICAL_ADDR + 0xffff) & ~0xffff 143291f3632SMatt Fleming#ifdef CONFIG_X86_32 14426725192SArvind Sankar .long image_base # ImageBase 145291f3632SMatt Fleming#else 14626725192SArvind Sankar .quad image_base # ImageBase 147291f3632SMatt Fleming#endif 148fa5c3501SMatt Fleming .long 0x20 # SectionAlignment 149743628e8SJordan Justen .long 0x20 # FileAlignment 150291f3632SMatt Fleming .word 0 # MajorOperatingSystemVersion 151291f3632SMatt Fleming .word 0 # MinorOperatingSystemVersion 152148d3f71SArd Biesheuvel .word LINUX_EFISTUB_MAJOR_VERSION # MajorImageVersion 153148d3f71SArd Biesheuvel .word LINUX_EFISTUB_MINOR_VERSION # MinorImageVersion 154291f3632SMatt Fleming .word 0 # MajorSubsystemVersion 155291f3632SMatt Fleming .word 0 # MinorSubsystemVersion 156291f3632SMatt Fleming .long 0 # Win32VersionValue 157291f3632SMatt Fleming 158291f3632SMatt Fleming # 159291f3632SMatt Fleming # The size of the bzImage is written in tools/build.c 160291f3632SMatt Fleming # 161291f3632SMatt Fleming .long 0 # SizeOfImage 162291f3632SMatt Fleming 163291f3632SMatt Fleming .long 0x200 # SizeOfHeaders 164291f3632SMatt Fleming .long 0 # CheckSum 165a3326a0dSArd Biesheuvel .word IMAGE_SUBSYSTEM_EFI_APPLICATION # Subsystem (EFI application) 166291f3632SMatt Fleming .word 0 # DllCharacteristics 167291f3632SMatt Fleming#ifdef CONFIG_X86_32 168291f3632SMatt Fleming .long 0 # SizeOfStackReserve 169291f3632SMatt Fleming .long 0 # SizeOfStackCommit 170291f3632SMatt Fleming .long 0 # SizeOfHeapReserve 171291f3632SMatt Fleming .long 0 # SizeOfHeapCommit 172291f3632SMatt Fleming#else 173291f3632SMatt Fleming .quad 0 # SizeOfStackReserve 174291f3632SMatt Fleming .quad 0 # SizeOfStackCommit 175291f3632SMatt Fleming .quad 0 # SizeOfHeapReserve 176291f3632SMatt Fleming .quad 0 # SizeOfHeapCommit 177291f3632SMatt Fleming#endif 178291f3632SMatt Fleming .long 0 # LoaderFlags 179a3326a0dSArd Biesheuvel .long (section_table - .) / 8 # NumberOfRvaAndSizes 180291f3632SMatt Fleming 181291f3632SMatt Fleming .quad 0 # ExportTable 182291f3632SMatt Fleming .quad 0 # ImportTable 183291f3632SMatt Fleming .quad 0 # ResourceTable 184291f3632SMatt Fleming .quad 0 # ExceptionTable 185291f3632SMatt Fleming .quad 0 # CertificationTable 186291f3632SMatt Fleming .quad 0 # BaseRelocationTable 187291f3632SMatt Fleming 188291f3632SMatt Fleming # Section table 189291f3632SMatt Flemingsection_table: 190743628e8SJordan Justen # 191743628e8SJordan Justen # The offset & size fields are filled in by build.c. 192743628e8SJordan Justen # 193743628e8SJordan Justen .ascii ".setup" 194291f3632SMatt Fleming .byte 0 195291f3632SMatt Fleming .byte 0 196291f3632SMatt Fleming .long 0 197291f3632SMatt Fleming .long 0x0 # startup_{32,64} 198291f3632SMatt Fleming .long 0 # Size of initialized data 199291f3632SMatt Fleming # on disk 200291f3632SMatt Fleming .long 0x0 # startup_{32,64} 201291f3632SMatt Fleming .long 0 # PointerToRelocations 202291f3632SMatt Fleming .long 0 # PointerToLineNumbers 203291f3632SMatt Fleming .word 0 # NumberOfRelocations 204291f3632SMatt Fleming .word 0 # NumberOfLineNumbers 205a3326a0dSArd Biesheuvel .long IMAGE_SCN_CNT_CODE | \ 206a3326a0dSArd Biesheuvel IMAGE_SCN_MEM_READ | \ 207a3326a0dSArd Biesheuvel IMAGE_SCN_MEM_EXECUTE | \ 208a3326a0dSArd Biesheuvel IMAGE_SCN_ALIGN_16BYTES # Characteristics 209291f3632SMatt Fleming 210291f3632SMatt Fleming # 211291f3632SMatt Fleming # The EFI application loader requires a relocation section 212743628e8SJordan Justen # because EFI applications must be relocatable. The .reloc 213743628e8SJordan Justen # offset & size fields are filled in by build.c. 214291f3632SMatt Fleming # 215291f3632SMatt Fleming .ascii ".reloc" 216291f3632SMatt Fleming .byte 0 217291f3632SMatt Fleming .byte 0 2182e064b1eSJordan Justen .long 0 2192e064b1eSJordan Justen .long 0 2202e064b1eSJordan Justen .long 0 # SizeOfRawData 2212e064b1eSJordan Justen .long 0 # PointerToRawData 222291f3632SMatt Fleming .long 0 # PointerToRelocations 223291f3632SMatt Fleming .long 0 # PointerToLineNumbers 224291f3632SMatt Fleming .word 0 # NumberOfRelocations 225291f3632SMatt Fleming .word 0 # NumberOfLineNumbers 226a3326a0dSArd Biesheuvel .long IMAGE_SCN_CNT_INITIALIZED_DATA | \ 227a3326a0dSArd Biesheuvel IMAGE_SCN_MEM_READ | \ 228a3326a0dSArd Biesheuvel IMAGE_SCN_MEM_DISCARDABLE | \ 229a3326a0dSArd Biesheuvel IMAGE_SCN_ALIGN_1BYTES # Characteristics 230743628e8SJordan Justen 23197aa2765SArd Biesheuvel#ifdef CONFIG_EFI_MIXED 23297aa2765SArd Biesheuvel # 23397aa2765SArd Biesheuvel # The offset & size fields are filled in by build.c. 23497aa2765SArd Biesheuvel # 23597aa2765SArd Biesheuvel .asciz ".compat" 23697aa2765SArd Biesheuvel .long 0 23797aa2765SArd Biesheuvel .long 0x0 23897aa2765SArd Biesheuvel .long 0 # Size of initialized data 23997aa2765SArd Biesheuvel # on disk 24097aa2765SArd Biesheuvel .long 0x0 24197aa2765SArd Biesheuvel .long 0 # PointerToRelocations 24297aa2765SArd Biesheuvel .long 0 # PointerToLineNumbers 24397aa2765SArd Biesheuvel .word 0 # NumberOfRelocations 24497aa2765SArd Biesheuvel .word 0 # NumberOfLineNumbers 245a3326a0dSArd Biesheuvel .long IMAGE_SCN_CNT_INITIALIZED_DATA | \ 246a3326a0dSArd Biesheuvel IMAGE_SCN_MEM_READ | \ 247a3326a0dSArd Biesheuvel IMAGE_SCN_MEM_DISCARDABLE | \ 248a3326a0dSArd Biesheuvel IMAGE_SCN_ALIGN_1BYTES # Characteristics 24997aa2765SArd Biesheuvel#endif 25097aa2765SArd Biesheuvel 251743628e8SJordan Justen # 252743628e8SJordan Justen # The offset & size fields are filled in by build.c. 253743628e8SJordan Justen # 254743628e8SJordan Justen .ascii ".text" 255743628e8SJordan Justen .byte 0 256743628e8SJordan Justen .byte 0 257743628e8SJordan Justen .byte 0 258743628e8SJordan Justen .long 0 259743628e8SJordan Justen .long 0x0 # startup_{32,64} 260743628e8SJordan Justen .long 0 # Size of initialized data 261743628e8SJordan Justen # on disk 262743628e8SJordan Justen .long 0x0 # startup_{32,64} 263743628e8SJordan Justen .long 0 # PointerToRelocations 264743628e8SJordan Justen .long 0 # PointerToLineNumbers 265743628e8SJordan Justen .word 0 # NumberOfRelocations 266743628e8SJordan Justen .word 0 # NumberOfLineNumbers 267a3326a0dSArd Biesheuvel .long IMAGE_SCN_CNT_CODE | \ 268a3326a0dSArd Biesheuvel IMAGE_SCN_MEM_READ | \ 269a3326a0dSArd Biesheuvel IMAGE_SCN_MEM_EXECUTE | \ 270a3326a0dSArd Biesheuvel IMAGE_SCN_ALIGN_16BYTES # Characteristics 271743628e8SJordan Justen 27297aa2765SArd Biesheuvel .set section_count, (. - section_table) / 40 273291f3632SMatt Fleming#endif /* CONFIG_EFI_STUB */ 27496ae6ea0SThomas Gleixner 27596ae6ea0SThomas Gleixner # Kernel attributes; used by setup. This is part 1 of the 27696ae6ea0SThomas Gleixner # header, from the old boot sector. 27796ae6ea0SThomas Gleixner 27896ae6ea0SThomas Gleixner .section ".header", "a" 27909c205afSH. Peter Anvin .globl sentinel 28009c205afSH. Peter Anvinsentinel: .byte 0xff, 0xff /* Used to detect broken loaders */ 28109c205afSH. Peter Anvin 28296ae6ea0SThomas Gleixner .globl hdr 28396ae6ea0SThomas Gleixnerhdr: 2845e47c478SH. Peter Anvinsetup_sects: .byte 0 /* Filled in by build.c */ 28596ae6ea0SThomas Gleixnerroot_flags: .word ROOT_RDONLY 2865e47c478SH. Peter Anvinsyssize: .long 0 /* Filled in by build.c */ 2875e47c478SH. Peter Anvinram_size: .word 0 /* Obsolete */ 28896ae6ea0SThomas Gleixnervid_mode: .word SVGA_MODE 2895e47c478SH. Peter Anvinroot_dev: .word 0 /* Filled in by build.c */ 29096ae6ea0SThomas Gleixnerboot_flag: .word 0xAA55 29196ae6ea0SThomas Gleixner 29296ae6ea0SThomas Gleixner # offset 512, entry point 29396ae6ea0SThomas Gleixner 29496ae6ea0SThomas Gleixner .globl _start 29596ae6ea0SThomas Gleixner_start: 29696ae6ea0SThomas Gleixner # Explicitly enter this as bytes, or the assembler 29796ae6ea0SThomas Gleixner # tries to generate a 3-byte jump here, which causes 29896ae6ea0SThomas Gleixner # everything else to push off to the wrong offset. 29996ae6ea0SThomas Gleixner .byte 0xeb # short (2-byte) jump 30096ae6ea0SThomas Gleixner .byte start_of_setup-1f 30196ae6ea0SThomas Gleixner1: 30296ae6ea0SThomas Gleixner 30396ae6ea0SThomas Gleixner # Part 2 of the header, from the old setup.S 30496ae6ea0SThomas Gleixner 30596ae6ea0SThomas Gleixner .ascii "HdrS" # header signature 306b3c72fc9SDaniel Kiper .word 0x020f # header version number (>= 0x0105) 30796ae6ea0SThomas Gleixner # or else old loadlin-1.5 will fail) 30896ae6ea0SThomas Gleixner .globl realmode_swtch 30996ae6ea0SThomas Gleixnerrealmode_swtch: .word 0, 0 # default_switch, SETUPSEG 3105e47c478SH. Peter Anvinstart_sys_seg: .word SYSSEG # obsolete and meaningless, but just 3115e47c478SH. Peter Anvin # in case something decided to "use" it 31296ae6ea0SThomas Gleixner .word kernel_version-512 # pointing to kernel version string 31396ae6ea0SThomas Gleixner # above section of header is compatible 31496ae6ea0SThomas Gleixner # with loadlin-1.5 (header v1.5). Don't 31596ae6ea0SThomas Gleixner # change it. 31696ae6ea0SThomas Gleixner 3175e47c478SH. Peter Anvintype_of_loader: .byte 0 # 0 means ancient bootloader, newer 3185e47c478SH. Peter Anvin # bootloaders know to change this. 319cb1aaebeSMauro Carvalho Chehab # See Documentation/x86/boot.rst for 32096ae6ea0SThomas Gleixner # assigned ids 32196ae6ea0SThomas Gleixner 32296ae6ea0SThomas Gleixner# flags, unused bits must be zero (RFU) bit within loadflags 32396ae6ea0SThomas Gleixnerloadflags: 32409c205afSH. Peter Anvin .byte LOADED_HIGH # The kernel is to be loaded high 32596ae6ea0SThomas Gleixner 32696ae6ea0SThomas Gleixnersetup_move_size: .word 0x8000 # size to move, when setup is not 32796ae6ea0SThomas Gleixner # loaded at 0x90000. We will move setup 32896ae6ea0SThomas Gleixner # to 0x90000 then just before jumping 32996ae6ea0SThomas Gleixner # into the kernel. However, only the 33096ae6ea0SThomas Gleixner # loader knows how much data behind 33196ae6ea0SThomas Gleixner # us also needs to be loaded. 33296ae6ea0SThomas Gleixner 33396ae6ea0SThomas Gleixnercode32_start: # here loaders can put a different 33496ae6ea0SThomas Gleixner # start address for 32-bit code. 33596ae6ea0SThomas Gleixner .long 0x100000 # 0x100000 = default for big kernel 33696ae6ea0SThomas Gleixner 33796ae6ea0SThomas Gleixnerramdisk_image: .long 0 # address of loaded ramdisk image 33896ae6ea0SThomas Gleixner # Here the loader puts the 32-bit 33996ae6ea0SThomas Gleixner # address where it loaded the image. 34096ae6ea0SThomas Gleixner # This only will be read by the kernel. 34196ae6ea0SThomas Gleixner 34296ae6ea0SThomas Gleixnerramdisk_size: .long 0 # its size in bytes 34396ae6ea0SThomas Gleixner 34496ae6ea0SThomas Gleixnerbootsect_kludge: 34596ae6ea0SThomas Gleixner .long 0 # obsolete 34696ae6ea0SThomas Gleixner 3476b6815c6SH. Peter Anvinheap_end_ptr: .word _end+STACK_SIZE-512 3486b6815c6SH. Peter Anvin # (Header version 0x0201 or later) 34996ae6ea0SThomas Gleixner # space from here (exclusive) down to 35096ae6ea0SThomas Gleixner # end of setup code can be used by setup 35196ae6ea0SThomas Gleixner # for local heap purposes. 35296ae6ea0SThomas Gleixner 3535031296cSH. Peter Anvinext_loader_ver: 3545031296cSH. Peter Anvin .byte 0 # Extended boot loader version 3555031296cSH. Peter Anvinext_loader_type: 3565031296cSH. Peter Anvin .byte 0 # Extended boot loader type 3575031296cSH. Peter Anvin 35896ae6ea0SThomas Gleixnercmd_line_ptr: .long 0 # (Header version 0x0202 or later) 35996ae6ea0SThomas Gleixner # If nonzero, a 32-bit pointer 36096ae6ea0SThomas Gleixner # to the kernel command line. 36196ae6ea0SThomas Gleixner # The command line should be 36296ae6ea0SThomas Gleixner # located between the start of 36396ae6ea0SThomas Gleixner # setup and the end of low 36496ae6ea0SThomas Gleixner # memory (0xa0000), or it may 36596ae6ea0SThomas Gleixner # get overwritten before it 36696ae6ea0SThomas Gleixner # gets read. If this field is 36796ae6ea0SThomas Gleixner # used, there is no longer 36896ae6ea0SThomas Gleixner # anything magical about the 36996ae6ea0SThomas Gleixner # 0x90000 segment; the setup 37096ae6ea0SThomas Gleixner # can be located anywhere in 37196ae6ea0SThomas Gleixner # low memory 0x10000 or higher. 37296ae6ea0SThomas Gleixner 3733e920b53SBorislav Petkovinitrd_addr_max: .long 0x7fffffff 37496ae6ea0SThomas Gleixner # (Header version 0x0203 or later) 37596ae6ea0SThomas Gleixner # The highest safe address for 37696ae6ea0SThomas Gleixner # the contents of an initrd 377cf8fa920SH. Peter Anvin # The current kernel allows up to 4 GB, 378cf8fa920SH. Peter Anvin # but leave it at 2 GB to avoid 379cf8fa920SH. Peter Anvin # possible bootloader bugs. 38096ae6ea0SThomas Gleixner 38196ae6ea0SThomas Gleixnerkernel_alignment: .long CONFIG_PHYSICAL_ALIGN #physical addr alignment 38296ae6ea0SThomas Gleixner #required for protected mode 38396ae6ea0SThomas Gleixner #kernel 38496ae6ea0SThomas Gleixner#ifdef CONFIG_RELOCATABLE 38596ae6ea0SThomas Gleixnerrelocatable_kernel: .byte 1 38696ae6ea0SThomas Gleixner#else 38796ae6ea0SThomas Gleixnerrelocatable_kernel: .byte 0 38896ae6ea0SThomas Gleixner#endif 38937ba7ab5SH. Peter Anvinmin_alignment: .byte MIN_KERNEL_ALIGN_LG2 # minimum alignment 39009c205afSH. Peter Anvin 39109c205afSH. Peter Anvinxloadflags: 39209c205afSH. Peter Anvin#ifdef CONFIG_X86_64 39309c205afSH. Peter Anvin# define XLF0 XLF_KERNEL_64 /* 64-bit kernel */ 39409c205afSH. Peter Anvin#else 39509c205afSH. Peter Anvin# define XLF0 0 39609c205afSH. Peter Anvin#endif 397ee92d815SYinghai Lu 398745c5167SMatt Fleming#if defined(CONFIG_RELOCATABLE) && defined(CONFIG_X86_64) 399ee92d815SYinghai Lu /* kernel/boot_param/ramdisk could be loaded above 4g */ 400ee92d815SYinghai Lu# define XLF1 XLF_CAN_BE_LOADED_ABOVE_4G 401ee92d815SYinghai Lu#else 402ee92d815SYinghai Lu# define XLF1 0 403ee92d815SYinghai Lu#endif 404ee92d815SYinghai Lu 40509c205afSH. Peter Anvin#ifdef CONFIG_EFI_STUB 4067d453eeeSMatt Fleming# ifdef CONFIG_EFI_MIXED 4077d453eeeSMatt Fleming# define XLF23 (XLF_EFI_HANDOVER_32|XLF_EFI_HANDOVER_64) 4087d453eeeSMatt Fleming# else 40909c205afSH. Peter Anvin# ifdef CONFIG_X86_64 41009c205afSH. Peter Anvin# define XLF23 XLF_EFI_HANDOVER_64 /* 64-bit EFI handover ok */ 41109c205afSH. Peter Anvin# else 41209c205afSH. Peter Anvin# define XLF23 XLF_EFI_HANDOVER_32 /* 32-bit EFI handover ok */ 41309c205afSH. Peter Anvin# endif 4147d453eeeSMatt Fleming# endif 41509c205afSH. Peter Anvin#else 41609c205afSH. Peter Anvin# define XLF23 0 41709c205afSH. Peter Anvin#endif 418456a29ddSDave Young 4192965faa5SDave Young#if defined(CONFIG_X86_64) && defined(CONFIG_EFI) && defined(CONFIG_KEXEC_CORE) 420456a29ddSDave Young# define XLF4 XLF_EFI_KEXEC 421456a29ddSDave Young#else 422456a29ddSDave Young# define XLF4 0 423456a29ddSDave Young#endif 424456a29ddSDave Young 425f2d08c5dSBaoquan He#ifdef CONFIG_X86_64 426f2d08c5dSBaoquan He#ifdef CONFIG_X86_5LEVEL 427f2d08c5dSBaoquan He#define XLF56 (XLF_5LEVEL|XLF_5LEVEL_ENABLED) 428f2d08c5dSBaoquan He#else 429f2d08c5dSBaoquan He#define XLF56 XLF_5LEVEL 430f2d08c5dSBaoquan He#endif 431f2d08c5dSBaoquan He#else 432f2d08c5dSBaoquan He#define XLF56 0 433f2d08c5dSBaoquan He#endif 434f2d08c5dSBaoquan He 435f2d08c5dSBaoquan He .word XLF0 | XLF1 | XLF23 | XLF4 | XLF56 43696ae6ea0SThomas Gleixner 43796ae6ea0SThomas Gleixnercmdline_size: .long COMMAND_LINE_SIZE-1 #length of the command line, 43896ae6ea0SThomas Gleixner #added with boot protocol 43996ae6ea0SThomas Gleixner #version 2.06 44096ae6ea0SThomas Gleixner 441a24e7851SRusty Russellhardware_subarch: .long 0 # subarchitecture, added with 2.07 442a24e7851SRusty Russell # default to 0 for normal x86 PC 443a24e7851SRusty Russell 444a24e7851SRusty Russellhardware_subarch_data: .quad 0 445a24e7851SRusty Russell 44677d1a499SH. Peter Anvinpayload_offset: .long ZO_input_data 44777d1a499SH. Peter Anvinpayload_length: .long ZO_z_input_len 448099e1377SIan Campbell 4498b664aa6SHuang, Yingsetup_data: .quad 0 # 64-bit physical pointer to 4508b664aa6SHuang, Ying # single linked list of 4518b664aa6SHuang, Ying # struct setup_data 4528b664aa6SHuang, Ying 45337ba7ab5SH. Peter Anvinpref_address: .quad LOAD_PHYSICAL_ADDR # preferred load addr 45437ba7ab5SH. Peter Anvin 4554252db10SBaoquan He# 4564252db10SBaoquan He# Getting to provably safe in-place decompression is hard. Worst case 4574252db10SBaoquan He# behaviours need to be analyzed. Here let's take the decompression of 4584252db10SBaoquan He# a gzip-compressed kernel as example, to illustrate it: 4594252db10SBaoquan He# 4604252db10SBaoquan He# The file layout of gzip compressed kernel is: 4614252db10SBaoquan He# 4624252db10SBaoquan He# magic[2] 4634252db10SBaoquan He# method[1] 4644252db10SBaoquan He# flags[1] 4654252db10SBaoquan He# timestamp[4] 4664252db10SBaoquan He# extraflags[1] 4674252db10SBaoquan He# os[1] 4684252db10SBaoquan He# compressed data blocks[N] 4694252db10SBaoquan He# crc[4] orig_len[4] 4704252db10SBaoquan He# 4714252db10SBaoquan He# ... resulting in +18 bytes overhead of uncompressed data. 4724252db10SBaoquan He# 4734252db10SBaoquan He# (For more information, please refer to RFC 1951 and RFC 1952.) 4744252db10SBaoquan He# 4754252db10SBaoquan He# Files divided into blocks 4764252db10SBaoquan He# 1 bit (last block flag) 4774252db10SBaoquan He# 2 bits (block type) 4784252db10SBaoquan He# 4794252db10SBaoquan He# 1 block occurs every 32K -1 bytes or when there 50% compression 4804252db10SBaoquan He# has been achieved. The smallest block type encoding is always used. 4814252db10SBaoquan He# 4824252db10SBaoquan He# stored: 4834252db10SBaoquan He# 32 bits length in bytes. 4844252db10SBaoquan He# 4854252db10SBaoquan He# fixed: 4864252db10SBaoquan He# magic fixed tree. 4874252db10SBaoquan He# symbols. 4884252db10SBaoquan He# 4894252db10SBaoquan He# dynamic: 4904252db10SBaoquan He# dynamic tree encoding. 4914252db10SBaoquan He# symbols. 4924252db10SBaoquan He# 4934252db10SBaoquan He# 4944252db10SBaoquan He# The buffer for decompression in place is the length of the uncompressed 4954252db10SBaoquan He# data, plus a small amount extra to keep the algorithm safe. The 4964252db10SBaoquan He# compressed data is placed at the end of the buffer. The output pointer 4974252db10SBaoquan He# is placed at the start of the buffer and the input pointer is placed 4984252db10SBaoquan He# where the compressed data starts. Problems will occur when the output 4994252db10SBaoquan He# pointer overruns the input pointer. 5004252db10SBaoquan He# 5014252db10SBaoquan He# The output pointer can only overrun the input pointer if the input 5024252db10SBaoquan He# pointer is moving faster than the output pointer. A condition only 5034252db10SBaoquan He# triggered by data whose compressed form is larger than the uncompressed 5044252db10SBaoquan He# form. 5054252db10SBaoquan He# 5064252db10SBaoquan He# The worst case at the block level is a growth of the compressed data 5074252db10SBaoquan He# of 5 bytes per 32767 bytes. 5084252db10SBaoquan He# 5094252db10SBaoquan He# The worst case internal to a compressed block is very hard to figure. 5104252db10SBaoquan He# The worst case can at least be bounded by having one bit that represents 5114252db10SBaoquan He# 32764 bytes and then all of the rest of the bytes representing the very 5124252db10SBaoquan He# very last byte. 5134252db10SBaoquan He# 5144252db10SBaoquan He# All of which is enough to compute an amount of extra data that is required 5154252db10SBaoquan He# to be safe. To avoid problems at the block level allocating 5 extra bytes 5164252db10SBaoquan He# per 32767 bytes of data is sufficient. To avoid problems internal to a 5174252db10SBaoquan He# block adding an extra 32767 bytes (the worst case uncompressed block size) 5184252db10SBaoquan He# is sufficient, to ensure that in the worst case the decompressed data for 5194252db10SBaoquan He# block will stop the byte before the compressed data for a block begins. 5204252db10SBaoquan He# To avoid problems with the compressed data's meta information an extra 18 5214252db10SBaoquan He# bytes are needed. Leading to the formula: 5224252db10SBaoquan He# 523d607251bSYinghai Lu# extra_bytes = (uncompressed_size >> 12) + 32768 + 18 5244252db10SBaoquan He# 5254252db10SBaoquan He# Adding 8 bytes per 32K is a bit excessive but much easier to calculate. 5264252db10SBaoquan He# Adding 32768 instead of 32767 just makes for round numbers. 5274252db10SBaoquan He# 5284252db10SBaoquan He# Above analysis is for decompressing gzip compressed kernel only. Up to 5294252db10SBaoquan He# now 6 different decompressor are supported all together. And among them 5304252db10SBaoquan He# xz stores data in chunks and has maximum chunk of 64K. Hence safety 5314252db10SBaoquan He# margin should be updated to cover all decompressors so that we don't 5324252db10SBaoquan He# need to deal with each of them separately. Please check 5334252db10SBaoquan He# the description in lib/decompressor_xxx.c for specific information. 5344252db10SBaoquan He# 5354252db10SBaoquan He# extra_bytes = (uncompressed_size >> 12) + 65536 + 128 5365746f055SJan H. Schönherr# 5375746f055SJan H. Schönherr# LZ4 is even worse: data that cannot be further compressed grows by 0.4%, 5385746f055SJan H. Schönherr# or one byte per 256 bytes. OTOH, we can safely get rid of the +128 as 5395746f055SJan H. Schönherr# the size-dependent part now grows so fast. 5405746f055SJan H. Schönherr# 5415746f055SJan H. Schönherr# extra_bytes = (uncompressed_size >> 8) + 65536 5420fe4f4efSNick Terrell# 5430fe4f4efSNick Terrell# ZSTD compressed data grows by at most 3 bytes per 128K, and only has a 22 5440fe4f4efSNick Terrell# byte fixed overhead but has a maximum block size of 128K, so it needs a 5450fe4f4efSNick Terrell# larger margin. 5460fe4f4efSNick Terrell# 5470fe4f4efSNick Terrell# extra_bytes = (uncompressed_size >> 8) + 131072 5484252db10SBaoquan He 5490fe4f4efSNick Terrell#define ZO_z_extra_bytes ((ZO_z_output_len >> 8) + 131072) 550d607251bSYinghai Lu#if ZO_z_output_len > ZO_z_input_len 551d607251bSYinghai Lu# define ZO_z_extract_offset (ZO_z_output_len + ZO_z_extra_bytes - \ 552d607251bSYinghai Lu ZO_z_input_len) 553d607251bSYinghai Lu#else 554d607251bSYinghai Lu# define ZO_z_extract_offset ZO_z_extra_bytes 555d607251bSYinghai Lu#endif 556d607251bSYinghai Lu 557d607251bSYinghai Lu/* 558d607251bSYinghai Lu * The extract_offset has to be bigger than ZO head section. Otherwise when 559d607251bSYinghai Lu * the head code is running to move ZO to the end of the buffer, it will 560d607251bSYinghai Lu * overwrite the head code itself. 561d607251bSYinghai Lu */ 562d607251bSYinghai Lu#if (ZO__ehead - ZO_startup_32) > ZO_z_extract_offset 563d607251bSYinghai Lu# define ZO_z_min_extract_offset ((ZO__ehead - ZO_startup_32 + 4095) & ~4095) 564d607251bSYinghai Lu#else 565d607251bSYinghai Lu# define ZO_z_min_extract_offset ((ZO_z_extract_offset + 4095) & ~4095) 566d607251bSYinghai Lu#endif 567d607251bSYinghai Lu 568d607251bSYinghai Lu#define ZO_INIT_SIZE (ZO__end - ZO_startup_32 + ZO_z_min_extract_offset) 569d607251bSYinghai Lu 57037ba7ab5SH. Peter Anvin#define VO_INIT_SIZE (VO__end - VO__text) 57137ba7ab5SH. Peter Anvin#if ZO_INIT_SIZE > VO_INIT_SIZE 57237ba7ab5SH. Peter Anvin# define INIT_SIZE ZO_INIT_SIZE 57337ba7ab5SH. Peter Anvin#else 57437ba7ab5SH. Peter Anvin# define INIT_SIZE VO_INIT_SIZE 57537ba7ab5SH. Peter Anvin#endif 576d607251bSYinghai Lu 57737ba7ab5SH. Peter Anvininit_size: .long INIT_SIZE # kernel initialization size 57886134a1bSMatt Fleminghandover_offset: .long 0 # Filled in by build.c 5792c33c27fSDaniel Kiperkernel_info_offset: .long 0 # Filled in by build.c 58037ba7ab5SH. Peter Anvin 58196ae6ea0SThomas Gleixner# End of setup header ##################################################### 58296ae6ea0SThomas Gleixner 5837a734e7dSH. Peter Anvin .section ".entrytext", "ax" 58496ae6ea0SThomas Gleixnerstart_of_setup: 58596ae6ea0SThomas Gleixner# Force %es = %ds 58696ae6ea0SThomas Gleixner movw %ds, %ax 58796ae6ea0SThomas Gleixner movw %ax, %es 58896ae6ea0SThomas Gleixner cld 58996ae6ea0SThomas Gleixner 59016252da6SJens Rottmann# Apparently some ancient versions of LILO invoked the kernel with %ss != %ds, 59116252da6SJens Rottmann# which happened to work by accident for the old code. Recalculate the stack 59216252da6SJens Rottmann# pointer if %ss is invalid. Otherwise leave it alone, LOADLIN sets up the 59316252da6SJens Rottmann# stack behind its own code, so we can't blindly put it directly past the heap. 5946b6815c6SH. Peter Anvin 5956b6815c6SH. Peter Anvin movw %ss, %dx 5966b6815c6SH. Peter Anvin cmpw %ax, %dx # %ds == %ss? 5976b6815c6SH. Peter Anvin movw %sp, %dx 59816252da6SJens Rottmann je 2f # -> assume %sp is reasonably set 5996b6815c6SH. Peter Anvin 60016252da6SJens Rottmann # Invalid %ss, make up a new stack 60116252da6SJens Rottmann movw $_end, %dx 60216252da6SJens Rottmann testb $CAN_USE_HEAP, loadflags 60316252da6SJens Rottmann jz 1f 60416252da6SJens Rottmann movw heap_end_ptr, %dx 60516252da6SJens Rottmann1: addw $STACK_SIZE, %dx 60616252da6SJens Rottmann jnc 2f 60716252da6SJens Rottmann xorw %dx, %dx # Prevent wraparound 60816252da6SJens Rottmann 60916252da6SJens Rottmann2: # Now %dx should point to the end of our stack space 6106b6815c6SH. Peter Anvin andw $~3, %dx # dword align (might as well...) 6116b6815c6SH. Peter Anvin jnz 3f 6126b6815c6SH. Peter Anvin movw $0xfffc, %dx # Make sure we're not zero 61316252da6SJens Rottmann3: movw %ax, %ss 6146b6815c6SH. Peter Anvin movzwl %dx, %esp # Clear upper half of %esp 6156b6815c6SH. Peter Anvin sti # Now we should have a working stack 6166b6815c6SH. Peter Anvin 6176b6815c6SH. Peter Anvin# We will have entered with %cs = %ds+0x20, normalize %cs so 6186b6815c6SH. Peter Anvin# it is on par with the other segments. 6196b6815c6SH. Peter Anvin pushw %ds 6206b6815c6SH. Peter Anvin pushw $6f 6216b6815c6SH. Peter Anvin lretw 6226b6815c6SH. Peter Anvin6: 62396ae6ea0SThomas Gleixner 62496ae6ea0SThomas Gleixner# Check signature at end of setup 62596ae6ea0SThomas Gleixner cmpl $0x5a5aaa55, setup_sig 62696ae6ea0SThomas Gleixner jne setup_bad 62796ae6ea0SThomas Gleixner 62896ae6ea0SThomas Gleixner# Zero the bss 62996ae6ea0SThomas Gleixner movw $__bss_start, %di 63096ae6ea0SThomas Gleixner movw $_end+3, %cx 63196ae6ea0SThomas Gleixner xorl %eax, %eax 63296ae6ea0SThomas Gleixner subw %di, %cx 63396ae6ea0SThomas Gleixner shrw $2, %cx 63496ae6ea0SThomas Gleixner rep; stosl 63596ae6ea0SThomas Gleixner 63696ae6ea0SThomas Gleixner# Jump to C code (should not return) 63796ae6ea0SThomas Gleixner calll main 63896ae6ea0SThomas Gleixner 63996ae6ea0SThomas Gleixner# Setup corrupt somehow... 64096ae6ea0SThomas Gleixnersetup_bad: 64196ae6ea0SThomas Gleixner movl $setup_corrupt, %eax 64296ae6ea0SThomas Gleixner calll puts 64396ae6ea0SThomas Gleixner # Fall through... 64496ae6ea0SThomas Gleixner 64596ae6ea0SThomas Gleixner .globl die 64696ae6ea0SThomas Gleixner .type die, @function 64796ae6ea0SThomas Gleixnerdie: 64896ae6ea0SThomas Gleixner hlt 64996ae6ea0SThomas Gleixner jmp die 65096ae6ea0SThomas Gleixner 65196ae6ea0SThomas Gleixner .size die, .-die 65296ae6ea0SThomas Gleixner 65396ae6ea0SThomas Gleixner .section ".initdata", "a" 65496ae6ea0SThomas Gleixnersetup_corrupt: 65596ae6ea0SThomas Gleixner .byte 7 65696ae6ea0SThomas Gleixner .string "No setup signature found...\n" 657