Fixed MTP to work with TWRP

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	CONFIG_PHYSICAL_ALIGN		# 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)
+# 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"