File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
new file mode 100644
index 0000000..6236b9e
--- /dev/null
+++ b/arch/x86/boot/header.S
@@ -0,0 +1,528 @@
+/*
+ * header.S
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * Based on bootsect.S and setup.S
+ * modified by more people than can be counted
+ *
+ * Rewritten as a common file by H. Peter Anvin (Apr 2007)
+ *
+ * BIG FAT NOTE: We're in real mode using 64k segments. Therefore segment
+ * addresses must be multiplied by 16 to obtain their respective linear
+ * addresses. To avoid confusion, linear addresses are written using leading
+ * hex while segment addresses are written as segment:offset.
+ *
+ */
+
+#include <asm/segment.h>
+#include <generated/utsrelease.h>
+#include <asm/boot.h>
+#include <asm/e820.h>
+#include <asm/page_types.h>
+#include <asm/setup.h>
+#include <asm/bootparam.h>
+#include "boot.h"
+#include "voffset.h"
+#include "zoffset.h"
+
+BOOTSEG = 0x07C0 /* original address of boot-sector */
+SYSSEG = 0x1000 /* historical load address >> 4 */
+
+#ifndef SVGA_MODE
+#define SVGA_MODE ASK_VGA
+#endif
+
+#ifndef ROOT_RDONLY
+#define ROOT_RDONLY 1
+#endif
+
+ .code16
+ .section ".bstext", "ax"
+
+ .global bootsect_start
+bootsect_start:
+#ifdef CONFIG_EFI_STUB
+ # "MZ", MS-DOS header
+ .byte 0x4d
+ .byte 0x5a
+#endif
+
+ # Normalize the start address
+ ljmp $BOOTSEG, $start2
+
+start2:
+ movw %cs, %ax
+ movw %ax, %ds
+ movw %ax, %es
+ movw %ax, %ss
+ xorw %sp, %sp
+ sti
+ cld
+
+ movw $bugger_off_msg, %si
+
+msg_loop:
+ lodsb
+ andb %al, %al
+ jz bs_die
+ movb $0xe, %ah
+ movw $7, %bx
+ int $0x10
+ jmp msg_loop
+
+bs_die:
+ # Allow the user to press a key, then reboot
+ xorw %ax, %ax
+ int $0x16
+ int $0x19
+
+ # int 0x19 should never return. In case it does anyway,
+ # invoke the BIOS reset code...
+ ljmp $0xf000,$0xfff0
+
+#ifdef CONFIG_EFI_STUB
+ .org 0x3c
+ #
+ # Offset to the PE header.
+ #
+ .long pe_header
+#endif /* CONFIG_EFI_STUB */
+
+ .section ".bsdata", "a"
+bugger_off_msg:
+ .ascii "Use a boot loader.\r\n"
+ .ascii "\n"
+ .ascii "Remove disk and press any key to reboot...\r\n"
+ .byte 0
+
+#ifdef CONFIG_EFI_STUB
+pe_header:
+ .ascii "PE"
+ .word 0
+
+coff_header:
+#ifdef CONFIG_X86_32
+ .word 0x14c # i386
+#else
+ .word 0x8664 # x86-64
+#endif
+ .word 4 # nr_sections
+ .long 0 # TimeDateStamp
+ .long 0 # PointerToSymbolTable
+ .long 1 # NumberOfSymbols
+ .word section_table - optional_header # SizeOfOptionalHeader
+#ifdef CONFIG_X86_32
+ .word 0x306 # Characteristics.
+ # IMAGE_FILE_32BIT_MACHINE |
+ # IMAGE_FILE_DEBUG_STRIPPED |
+ # IMAGE_FILE_EXECUTABLE_IMAGE |
+ # IMAGE_FILE_LINE_NUMS_STRIPPED
+#else
+ .word 0x206 # Characteristics
+ # IMAGE_FILE_DEBUG_STRIPPED |
+ # IMAGE_FILE_EXECUTABLE_IMAGE |
+ # IMAGE_FILE_LINE_NUMS_STRIPPED
+#endif
+
+optional_header:
+#ifdef CONFIG_X86_32
+ .word 0x10b # PE32 format
+#else
+ .word 0x20b # PE32+ format
+#endif
+ .byte 0x02 # MajorLinkerVersion
+ .byte 0x14 # MinorLinkerVersion
+
+ # Filled in by build.c
+ .long 0 # SizeOfCode
+
+ .long 0 # SizeOfInitializedData
+ .long 0 # SizeOfUninitializedData
+
+ # Filled in by build.c
+ .long 0x0000 # AddressOfEntryPoint
+
+ .long 0x0200 # BaseOfCode
+#ifdef CONFIG_X86_32
+ .long 0 # data
+#endif
+
+extra_header_fields:
+#ifdef CONFIG_X86_32
+ .long 0 # ImageBase
+#else
+ .quad 0 # ImageBase
+#endif
+ .long 0x20 # SectionAlignment
+ .long 0x20 # FileAlignment
+ .word 0 # MajorOperatingSystemVersion
+ .word 0 # MinorOperatingSystemVersion
+ .word 0 # MajorImageVersion
+ .word 0 # MinorImageVersion
+ .word 0 # MajorSubsystemVersion
+ .word 0 # MinorSubsystemVersion
+ .long 0 # Win32VersionValue
+
+ #
+ # The size of the bzImage is written in tools/build.c
+ #
+ .long 0 # SizeOfImage
+
+ .long 0x200 # SizeOfHeaders
+ .long 0 # CheckSum
+ .word 0xa # Subsystem (EFI application)
+ .word 0 # DllCharacteristics
+#ifdef CONFIG_X86_32
+ .long 0 # SizeOfStackReserve
+ .long 0 # SizeOfStackCommit
+ .long 0 # SizeOfHeapReserve
+ .long 0 # SizeOfHeapCommit
+#else
+ .quad 0 # SizeOfStackReserve
+ .quad 0 # SizeOfStackCommit
+ .quad 0 # SizeOfHeapReserve
+ .quad 0 # SizeOfHeapCommit
+#endif
+ .long 0 # LoaderFlags
+ .long 0x6 # NumberOfRvaAndSizes
+
+ .quad 0 # ExportTable
+ .quad 0 # ImportTable
+ .quad 0 # ResourceTable
+ .quad 0 # ExceptionTable
+ .quad 0 # CertificationTable
+ .quad 0 # BaseRelocationTable
+
+ # Section table
+section_table:
+ #
+ # The offset & size fields are filled in by build.c.
+ #
+ .ascii ".setup"
+ .byte 0
+ .byte 0
+ .long 0
+ .long 0x0 # startup_{32,64}
+ .long 0 # Size of initialized data
+ # on disk
+ .long 0x0 # startup_{32,64}
+ .long 0 # PointerToRelocations
+ .long 0 # PointerToLineNumbers
+ .word 0 # NumberOfRelocations
+ .word 0 # NumberOfLineNumbers
+ .long 0x60500020 # Characteristics (section flags)
+
+ #
+ # The EFI application loader requires a relocation section
+ # because EFI applications must be relocatable. The .reloc
+ # offset & size fields are filled in by build.c.
+ #
+ .ascii ".reloc"
+ .byte 0
+ .byte 0
+ .long 0
+ .long 0
+ .long 0 # SizeOfRawData
+ .long 0 # PointerToRawData
+ .long 0 # PointerToRelocations
+ .long 0 # PointerToLineNumbers
+ .word 0 # NumberOfRelocations
+ .word 0 # NumberOfLineNumbers
+ .long 0x42100040 # Characteristics (section flags)
+
+ #
+ # The offset & size fields are filled in by build.c.
+ #
+ .ascii ".text"
+ .byte 0
+ .byte 0
+ .byte 0
+ .long 0
+ .long 0x0 # startup_{32,64}
+ .long 0 # Size of initialized data
+ # on disk
+ .long 0x0 # startup_{32,64}
+ .long 0 # PointerToRelocations
+ .long 0 # PointerToLineNumbers
+ .word 0 # NumberOfRelocations
+ .word 0 # NumberOfLineNumbers
+ .long 0x60500020 # Characteristics (section flags)
+
+ #
+ # The offset & size fields are filled in by build.c.
+ #
+ .ascii ".bss"
+ .byte 0
+ .byte 0
+ .byte 0
+ .byte 0
+ .long 0
+ .long 0x0
+ .long 0 # Size of initialized data
+ # on disk
+ .long 0x0
+ .long 0 # PointerToRelocations
+ .long 0 # PointerToLineNumbers
+ .word 0 # NumberOfRelocations
+ .word 0 # NumberOfLineNumbers
+ .long 0xc8000080 # Characteristics (section flags)
+
+#endif /* CONFIG_EFI_STUB */
+
+ # Kernel attributes; used by setup. This is part 1 of the
+ # header, from the old boot sector.
+
+ .section ".header", "a"
+ .globl sentinel
+sentinel: .byte 0xff, 0xff /* Used to detect broken loaders */
+
+ .globl hdr
+hdr:
+setup_sects: .byte 0 /* Filled in by build.c */
+root_flags: .word ROOT_RDONLY
+syssize: .long 0 /* Filled in by build.c */
+ram_size: .word 0 /* Obsolete */
+vid_mode: .word SVGA_MODE
+root_dev: .word 0 /* Filled in by build.c */
+boot_flag: .word 0xAA55
+
+ # offset 512, entry point
+
+ .globl _start
+_start:
+ # Explicitly enter this as bytes, or the assembler
+ # tries to generate a 3-byte jump here, which causes
+ # everything else to push off to the wrong offset.
+ .byte 0xeb # short (2-byte) jump
+ .byte start_of_setup-1f
+1:
+
+ # Part 2 of the header, from the old setup.S
+
+ .ascii "HdrS" # header signature
+ .word 0x020d # header version number (>= 0x0105)
+ # or else old loadlin-1.5 will fail)
+ .globl realmode_swtch
+realmode_swtch: .word 0, 0 # default_switch, SETUPSEG
+start_sys_seg: .word SYSSEG # obsolete and meaningless, but just
+ # in case something decided to "use" it
+ .word kernel_version-512 # pointing to kernel version string
+ # above section of header is compatible
+ # with loadlin-1.5 (header v1.5). Don't
+ # change it.
+
+type_of_loader: .byte 0 # 0 means ancient bootloader, newer
+ # bootloaders know to change this.
+ # See Documentation/x86/boot.txt for
+ # assigned ids
+
+# flags, unused bits must be zero (RFU) bit within loadflags
+loadflags:
+ .byte LOADED_HIGH # The kernel is to be loaded high
+
+setup_move_size: .word 0x8000 # size to move, when setup is not
+ # loaded at 0x90000. We will move setup
+ # to 0x90000 then just before jumping
+ # into the kernel. However, only the
+ # loader knows how much data behind
+ # us also needs to be loaded.
+
+code32_start: # here loaders can put a different
+ # start address for 32-bit code.
+ .long 0x100000 # 0x100000 = default for big kernel
+
+ramdisk_image: .long 0 # address of loaded ramdisk image
+ # Here the loader puts the 32-bit
+ # address where it loaded the image.
+ # This only will be read by the kernel.
+
+ramdisk_size: .long 0 # its size in bytes
+
+bootsect_kludge:
+ .long 0 # obsolete
+
+heap_end_ptr: .word _end+STACK_SIZE-512
+ # (Header version 0x0201 or later)
+ # space from here (exclusive) down to
+ # end of setup code can be used by setup
+ # for local heap purposes.
+
+ext_loader_ver:
+ .byte 0 # Extended boot loader version
+ext_loader_type:
+ .byte 0 # Extended boot loader type
+
+cmd_line_ptr: .long 0 # (Header version 0x0202 or later)
+ # If nonzero, a 32-bit pointer
+ # to the kernel command line.
+ # The command line should be
+ # located between the start of
+ # setup and the end of low
+ # memory (0xa0000), or it may
+ # get overwritten before it
+ # gets read. If this field is
+ # used, there is no longer
+ # anything magical about the
+ # 0x90000 segment; the setup
+ # can be located anywhere in
+ # low memory 0x10000 or higher.
+
+initrd_addr_max: .long 0x7fffffff
+ # (Header version 0x0203 or later)
+ # The highest safe address for
+ # the contents of an initrd
+ # The current kernel allows up to 4 GB,
+ # but leave it at 2 GB to avoid
+ # possible bootloader bugs.
+
+kernel_alignment: .long CONFIG_PHYSICAL_ALIGN #physical addr alignment
+ #required for protected mode
+ #kernel
+#ifdef CONFIG_RELOCATABLE
+relocatable_kernel: .byte 1
+#else
+relocatable_kernel: .byte 0
+#endif
+min_alignment: .byte MIN_KERNEL_ALIGN_LG2 # minimum alignment
+
+xloadflags:
+#ifdef CONFIG_X86_64
+# define XLF0 XLF_KERNEL_64 /* 64-bit kernel */
+#else
+# define XLF0 0
+#endif
+
+#if defined(CONFIG_RELOCATABLE) && defined(CONFIG_X86_64)
+ /* kernel/boot_param/ramdisk could be loaded above 4g */
+# define XLF1 XLF_CAN_BE_LOADED_ABOVE_4G
+#else
+# define XLF1 0
+#endif
+
+#ifdef CONFIG_EFI_STUB
+# ifdef CONFIG_EFI_MIXED
+# define XLF23 (XLF_EFI_HANDOVER_32|XLF_EFI_HANDOVER_64)
+# else
+# ifdef CONFIG_X86_64
+# define XLF23 XLF_EFI_HANDOVER_64 /* 64-bit EFI handover ok */
+# else
+# define XLF23 XLF_EFI_HANDOVER_32 /* 32-bit EFI handover ok */
+# endif
+# endif
+#else
+# define XLF23 0
+#endif
+
+#if defined(CONFIG_X86_64) && defined(CONFIG_EFI) && defined(CONFIG_KEXEC_CORE)
+# define XLF4 XLF_EFI_KEXEC
+#else
+# define XLF4 0
+#endif
+
+ .word XLF0 | XLF1 | XLF23 | XLF4
+
+cmdline_size: .long COMMAND_LINE_SIZE-1 #length of the command line,
+ #added with boot protocol
+ #version 2.06
+
+hardware_subarch: .long 0 # subarchitecture, added with 2.07
+ # default to 0 for normal x86 PC
+
+hardware_subarch_data: .quad 0
+
+payload_offset: .long ZO_input_data
+payload_length: .long ZO_z_input_len
+
+setup_data: .quad 0 # 64-bit physical pointer to
+ # single linked list of
+ # struct setup_data
+
+pref_address: .quad LOAD_PHYSICAL_ADDR # preferred load addr
+
+#define ZO_INIT_SIZE (ZO__end - ZO_startup_32 + ZO_z_extract_offset)
+#define VO_INIT_SIZE (VO__end - VO__text)
+#if ZO_INIT_SIZE > VO_INIT_SIZE
+#define INIT_SIZE ZO_INIT_SIZE
+#else
+#define INIT_SIZE VO_INIT_SIZE
+#endif
+init_size: .long INIT_SIZE # kernel initialization size
+handover_offset: .long 0 # Filled in by build.c
+
+# End of setup header #####################################################
+
+ .section ".entrytext", "ax"
+start_of_setup:
+# Force %es = %ds
+ movw %ds, %ax
+ movw %ax, %es
+ cld
+
+# Apparently some ancient versions of LILO invoked the kernel with %ss != %ds,
+# which happened to work by accident for the old code. Recalculate the stack
+# pointer if %ss is invalid. Otherwise leave it alone, LOADLIN sets up the
+# stack behind its own code, so we can't blindly put it directly past the heap.
+
+ movw %ss, %dx
+ cmpw %ax, %dx # %ds == %ss?
+ movw %sp, %dx
+ je 2f # -> assume %sp is reasonably set
+
+ # Invalid %ss, make up a new stack
+ movw $_end, %dx
+ testb $CAN_USE_HEAP, loadflags
+ jz 1f
+ movw heap_end_ptr, %dx
+1: addw $STACK_SIZE, %dx
+ jnc 2f
+ xorw %dx, %dx # Prevent wraparound
+
+2: # Now %dx should point to the end of our stack space
+ andw $~3, %dx # dword align (might as well...)
+ jnz 3f
+ movw $0xfffc, %dx # Make sure we're not zero
+3: movw %ax, %ss
+ movzwl %dx, %esp # Clear upper half of %esp
+ sti # Now we should have a working stack
+
+# We will have entered with %cs = %ds+0x20, normalize %cs so
+# it is on par with the other segments.
+ pushw %ds
+ pushw $6f
+ lretw
+6:
+
+# Check signature at end of setup
+ cmpl $0x5a5aaa55, setup_sig
+ jne setup_bad
+
+# Zero the bss
+ movw $__bss_start, %di
+ movw $_end+3, %cx
+ xorl %eax, %eax
+ subw %di, %cx
+ shrw $2, %cx
+ rep; stosl
+
+# Jump to C code (should not return)
+ calll main
+
+# Setup corrupt somehow...
+setup_bad:
+ movl $setup_corrupt, %eax
+ calll puts
+ # Fall through...
+
+ .globl die
+ .type die, @function
+die:
+ hlt
+ jmp die
+
+ .size die, .-die
+
+ .section ".initdata", "a"
+setup_corrupt:
+ .byte 7
+ .string "No setup signature found...\n"