Blame view

kernel/linux-imx6_3.14.28/arch/x86/boot/header.S 12.7 KB
6b13f685e   김민수   BSP 최초 추가
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
  /*
   *	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
  "
  	.ascii	"
  "
  	.ascii	"Remove disk and press any key to reboot...\r
  "
  	.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	0x020c		# 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.
  
  ramdisk_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_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
  #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:
  #ifdef CONFIG_EFI_STUB
    			.long 0x30		# offset to the handover
  						# protocol entry point
  #else
  			.long 0
  #endif
  
  # 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...
  "