Merge tag 'please-pull-morepstore' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6-microblaze.git] / arch / x86 / boot / header.S
1 /*
2  *      header.S
3  *
4  *      Copyright (C) 1991, 1992 Linus Torvalds
5  *
6  *      Based on bootsect.S and setup.S
7  *      modified by more people than can be counted
8  *
9  *      Rewritten as a common file by H. Peter Anvin (Apr 2007)
10  *
11  * BIG FAT NOTE: We're in real mode using 64k segments.  Therefore segment
12  * addresses must be multiplied by 16 to obtain their respective linear
13  * addresses. To avoid confusion, linear addresses are written using leading
14  * hex while segment addresses are written as segment:offset.
15  *
16  */
17
18 #include <asm/segment.h>
19 #include <generated/utsrelease.h>
20 #include <asm/boot.h>
21 #include <asm/e820.h>
22 #include <asm/page_types.h>
23 #include <asm/setup.h>
24 #include <asm/bootparam.h>
25 #include "boot.h"
26 #include "voffset.h"
27 #include "zoffset.h"
28
29 BOOTSEG         = 0x07C0                /* original address of boot-sector */
30 SYSSEG          = 0x1000                /* historical load address >> 4 */
31
32 #ifndef SVGA_MODE
33 #define SVGA_MODE ASK_VGA
34 #endif
35
36 #ifndef ROOT_RDONLY
37 #define ROOT_RDONLY 1
38 #endif
39
40         .code16
41         .section ".bstext", "ax"
42
43         .global bootsect_start
44 bootsect_start:
45 #ifdef CONFIG_EFI_STUB
46         # "MZ", MS-DOS header
47         .byte 0x4d
48         .byte 0x5a
49 #endif
50
51         # Normalize the start address
52         ljmp    $BOOTSEG, $start2
53
54 start2:
55         movw    %cs, %ax
56         movw    %ax, %ds
57         movw    %ax, %es
58         movw    %ax, %ss
59         xorw    %sp, %sp
60         sti
61         cld
62
63         movw    $bugger_off_msg, %si
64
65 msg_loop:
66         lodsb
67         andb    %al, %al
68         jz      bs_die
69         movb    $0xe, %ah
70         movw    $7, %bx
71         int     $0x10
72         jmp     msg_loop
73
74 bs_die:
75         # Allow the user to press a key, then reboot
76         xorw    %ax, %ax
77         int     $0x16
78         int     $0x19
79
80         # int 0x19 should never return.  In case it does anyway,
81         # invoke the BIOS reset code...
82         ljmp    $0xf000,$0xfff0
83
84 #ifdef CONFIG_EFI_STUB
85         .org    0x3c
86         #
87         # Offset to the PE header.
88         #
89         .long   pe_header
90 #endif /* CONFIG_EFI_STUB */
91
92         .section ".bsdata", "a"
93 bugger_off_msg:
94         .ascii  "Use a boot loader.\r\n"
95         .ascii  "\n"
96         .ascii  "Remove disk and press any key to reboot...\r\n"
97         .byte   0
98
99 #ifdef CONFIG_EFI_STUB
100 pe_header:
101         .ascii  "PE"
102         .word   0
103
104 coff_header:
105 #ifdef CONFIG_X86_32
106         .word   0x14c                           # i386
107 #else
108         .word   0x8664                          # x86-64
109 #endif
110         .word   4                               # nr_sections
111         .long   0                               # TimeDateStamp
112         .long   0                               # PointerToSymbolTable
113         .long   1                               # NumberOfSymbols
114         .word   section_table - optional_header # SizeOfOptionalHeader
115 #ifdef CONFIG_X86_32
116         .word   0x306                           # Characteristics.
117                                                 # IMAGE_FILE_32BIT_MACHINE |
118                                                 # IMAGE_FILE_DEBUG_STRIPPED |
119                                                 # IMAGE_FILE_EXECUTABLE_IMAGE |
120                                                 # IMAGE_FILE_LINE_NUMS_STRIPPED
121 #else
122         .word   0x206                           # Characteristics
123                                                 # IMAGE_FILE_DEBUG_STRIPPED |
124                                                 # IMAGE_FILE_EXECUTABLE_IMAGE |
125                                                 # IMAGE_FILE_LINE_NUMS_STRIPPED
126 #endif
127
128 optional_header:
129 #ifdef CONFIG_X86_32
130         .word   0x10b                           # PE32 format
131 #else
132         .word   0x20b                           # PE32+ format
133 #endif
134         .byte   0x02                            # MajorLinkerVersion
135         .byte   0x14                            # MinorLinkerVersion
136
137         # Filled in by build.c
138         .long   0                               # SizeOfCode
139
140         .long   0                               # SizeOfInitializedData
141         .long   0                               # SizeOfUninitializedData
142
143         # Filled in by build.c
144         .long   0x0000                          # AddressOfEntryPoint
145
146         .long   0x0200                          # BaseOfCode
147 #ifdef CONFIG_X86_32
148         .long   0                               # data
149 #endif
150
151 extra_header_fields:
152 #ifdef CONFIG_X86_32
153         .long   0                               # ImageBase
154 #else
155         .quad   0                               # ImageBase
156 #endif
157         .long   CONFIG_PHYSICAL_ALIGN           # SectionAlignment
158         .long   0x20                            # FileAlignment
159         .word   0                               # MajorOperatingSystemVersion
160         .word   0                               # MinorOperatingSystemVersion
161         .word   0                               # MajorImageVersion
162         .word   0                               # MinorImageVersion
163         .word   0                               # MajorSubsystemVersion
164         .word   0                               # MinorSubsystemVersion
165         .long   0                               # Win32VersionValue
166
167         #
168         # The size of the bzImage is written in tools/build.c
169         #
170         .long   0                               # SizeOfImage
171
172         .long   0x200                           # SizeOfHeaders
173         .long   0                               # CheckSum
174         .word   0xa                             # Subsystem (EFI application)
175         .word   0                               # DllCharacteristics
176 #ifdef CONFIG_X86_32
177         .long   0                               # SizeOfStackReserve
178         .long   0                               # SizeOfStackCommit
179         .long   0                               # SizeOfHeapReserve
180         .long   0                               # SizeOfHeapCommit
181 #else
182         .quad   0                               # SizeOfStackReserve
183         .quad   0                               # SizeOfStackCommit
184         .quad   0                               # SizeOfHeapReserve
185         .quad   0                               # SizeOfHeapCommit
186 #endif
187         .long   0                               # LoaderFlags
188         .long   0x6                             # NumberOfRvaAndSizes
189
190         .quad   0                               # ExportTable
191         .quad   0                               # ImportTable
192         .quad   0                               # ResourceTable
193         .quad   0                               # ExceptionTable
194         .quad   0                               # CertificationTable
195         .quad   0                               # BaseRelocationTable
196
197         # Section table
198 section_table:
199         #
200         # The offset & size fields are filled in by build.c.
201         #
202         .ascii  ".setup"
203         .byte   0
204         .byte   0
205         .long   0
206         .long   0x0                             # startup_{32,64}
207         .long   0                               # Size of initialized data
208                                                 # on disk
209         .long   0x0                             # startup_{32,64}
210         .long   0                               # PointerToRelocations
211         .long   0                               # PointerToLineNumbers
212         .word   0                               # NumberOfRelocations
213         .word   0                               # NumberOfLineNumbers
214         .long   0x60500020                      # Characteristics (section flags)
215
216         #
217         # The EFI application loader requires a relocation section
218         # because EFI applications must be relocatable. The .reloc
219         # offset & size fields are filled in by build.c.
220         #
221         .ascii  ".reloc"
222         .byte   0
223         .byte   0
224         .long   0
225         .long   0
226         .long   0                               # SizeOfRawData
227         .long   0                               # PointerToRawData
228         .long   0                               # PointerToRelocations
229         .long   0                               # PointerToLineNumbers
230         .word   0                               # NumberOfRelocations
231         .word   0                               # NumberOfLineNumbers
232         .long   0x42100040                      # Characteristics (section flags)
233
234         #
235         # The offset & size fields are filled in by build.c.
236         #
237         .ascii  ".text"
238         .byte   0
239         .byte   0
240         .byte   0
241         .long   0
242         .long   0x0                             # startup_{32,64}
243         .long   0                               # Size of initialized data
244                                                 # on disk
245         .long   0x0                             # startup_{32,64}
246         .long   0                               # PointerToRelocations
247         .long   0                               # PointerToLineNumbers
248         .word   0                               # NumberOfRelocations
249         .word   0                               # NumberOfLineNumbers
250         .long   0x60500020                      # Characteristics (section flags)
251
252         #
253         # The offset & size fields are filled in by build.c.
254         #
255         .ascii  ".bss"
256         .byte   0
257         .byte   0
258         .byte   0
259         .byte   0
260         .long   0
261         .long   0x0
262         .long   0                               # Size of initialized data
263                                                 # on disk
264         .long   0x0
265         .long   0                               # PointerToRelocations
266         .long   0                               # PointerToLineNumbers
267         .word   0                               # NumberOfRelocations
268         .word   0                               # NumberOfLineNumbers
269         .long   0xc8000080                      # Characteristics (section flags)
270
271 #endif /* CONFIG_EFI_STUB */
272
273         # Kernel attributes; used by setup.  This is part 1 of the
274         # header, from the old boot sector.
275
276         .section ".header", "a"
277         .globl  sentinel
278 sentinel:       .byte 0xff, 0xff        /* Used to detect broken loaders */
279
280         .globl  hdr
281 hdr:
282 setup_sects:    .byte 0                 /* Filled in by build.c */
283 root_flags:     .word ROOT_RDONLY
284 syssize:        .long 0                 /* Filled in by build.c */
285 ram_size:       .word 0                 /* Obsolete */
286 vid_mode:       .word SVGA_MODE
287 root_dev:       .word 0                 /* Filled in by build.c */
288 boot_flag:      .word 0xAA55
289
290         # offset 512, entry point
291
292         .globl  _start
293 _start:
294                 # Explicitly enter this as bytes, or the assembler
295                 # tries to generate a 3-byte jump here, which causes
296                 # everything else to push off to the wrong offset.
297                 .byte   0xeb            # short (2-byte) jump
298                 .byte   start_of_setup-1f
299 1:
300
301         # Part 2 of the header, from the old setup.S
302
303                 .ascii  "HdrS"          # header signature
304                 .word   0x020d          # header version number (>= 0x0105)
305                                         # or else old loadlin-1.5 will fail)
306                 .globl realmode_swtch
307 realmode_swtch: .word   0, 0            # default_switch, SETUPSEG
308 start_sys_seg:  .word   SYSSEG          # obsolete and meaningless, but just
309                                         # in case something decided to "use" it
310                 .word   kernel_version-512 # pointing to kernel version string
311                                         # above section of header is compatible
312                                         # with loadlin-1.5 (header v1.5). Don't
313                                         # change it.
314
315 type_of_loader: .byte   0               # 0 means ancient bootloader, newer
316                                         # bootloaders know to change this.
317                                         # See Documentation/x86/boot.txt for
318                                         # assigned ids
319
320 # flags, unused bits must be zero (RFU) bit within loadflags
321 loadflags:
322                 .byte   LOADED_HIGH     # The kernel is to be loaded high
323
324 setup_move_size: .word  0x8000          # size to move, when setup is not
325                                         # loaded at 0x90000. We will move setup
326                                         # to 0x90000 then just before jumping
327                                         # into the kernel. However, only the
328                                         # loader knows how much data behind
329                                         # us also needs to be loaded.
330
331 code32_start:                           # here loaders can put a different
332                                         # start address for 32-bit code.
333                 .long   0x100000        # 0x100000 = default for big kernel
334
335 ramdisk_image:  .long   0               # address of loaded ramdisk image
336                                         # Here the loader puts the 32-bit
337                                         # address where it loaded the image.
338                                         # This only will be read by the kernel.
339
340 ramdisk_size:   .long   0               # its size in bytes
341
342 bootsect_kludge:
343                 .long   0               # obsolete
344
345 heap_end_ptr:   .word   _end+STACK_SIZE-512
346                                         # (Header version 0x0201 or later)
347                                         # space from here (exclusive) down to
348                                         # end of setup code can be used by setup
349                                         # for local heap purposes.
350
351 ext_loader_ver:
352                 .byte   0               # Extended boot loader version
353 ext_loader_type:
354                 .byte   0               # Extended boot loader type
355
356 cmd_line_ptr:   .long   0               # (Header version 0x0202 or later)
357                                         # If nonzero, a 32-bit pointer
358                                         # to the kernel command line.
359                                         # The command line should be
360                                         # located between the start of
361                                         # setup and the end of low
362                                         # memory (0xa0000), or it may
363                                         # get overwritten before it
364                                         # gets read.  If this field is
365                                         # used, there is no longer
366                                         # anything magical about the
367                                         # 0x90000 segment; the setup
368                                         # can be located anywhere in
369                                         # low memory 0x10000 or higher.
370
371 initrd_addr_max: .long 0x7fffffff
372                                         # (Header version 0x0203 or later)
373                                         # The highest safe address for
374                                         # the contents of an initrd
375                                         # The current kernel allows up to 4 GB,
376                                         # but leave it at 2 GB to avoid
377                                         # possible bootloader bugs.
378
379 kernel_alignment:  .long CONFIG_PHYSICAL_ALIGN  #physical addr alignment
380                                                 #required for protected mode
381                                                 #kernel
382 #ifdef CONFIG_RELOCATABLE
383 relocatable_kernel:    .byte 1
384 #else
385 relocatable_kernel:    .byte 0
386 #endif
387 min_alignment:          .byte MIN_KERNEL_ALIGN_LG2      # minimum alignment
388
389 xloadflags:
390 #ifdef CONFIG_X86_64
391 # define XLF0 XLF_KERNEL_64                     /* 64-bit kernel */
392 #else
393 # define XLF0 0
394 #endif
395
396 #if defined(CONFIG_RELOCATABLE) && defined(CONFIG_X86_64)
397    /* kernel/boot_param/ramdisk could be loaded above 4g */
398 # define XLF1 XLF_CAN_BE_LOADED_ABOVE_4G
399 #else
400 # define XLF1 0
401 #endif
402
403 #ifdef CONFIG_EFI_STUB
404 # ifdef CONFIG_EFI_MIXED
405 #  define XLF23 (XLF_EFI_HANDOVER_32|XLF_EFI_HANDOVER_64)
406 # else
407 #  ifdef CONFIG_X86_64
408 #   define XLF23 XLF_EFI_HANDOVER_64            /* 64-bit EFI handover ok */
409 #  else
410 #   define XLF23 XLF_EFI_HANDOVER_32            /* 32-bit EFI handover ok */
411 #  endif
412 # endif
413 #else
414 # define XLF23 0
415 #endif
416
417 #if defined(CONFIG_X86_64) && defined(CONFIG_EFI) && defined(CONFIG_KEXEC)
418 # define XLF4 XLF_EFI_KEXEC
419 #else
420 # define XLF4 0
421 #endif
422
423                         .word XLF0 | XLF1 | XLF23 | XLF4
424
425 cmdline_size:   .long   COMMAND_LINE_SIZE-1     #length of the command line,
426                                                 #added with boot protocol
427                                                 #version 2.06
428
429 hardware_subarch:       .long 0                 # subarchitecture, added with 2.07
430                                                 # default to 0 for normal x86 PC
431
432 hardware_subarch_data:  .quad 0
433
434 payload_offset:         .long ZO_input_data
435 payload_length:         .long ZO_z_input_len
436
437 setup_data:             .quad 0                 # 64-bit physical pointer to
438                                                 # single linked list of
439                                                 # struct setup_data
440
441 pref_address:           .quad LOAD_PHYSICAL_ADDR        # preferred load addr
442
443 #define ZO_INIT_SIZE    (ZO__end - ZO_startup_32 + ZO_z_extract_offset)
444 #define VO_INIT_SIZE    (VO__end - VO__text)
445 #if ZO_INIT_SIZE > VO_INIT_SIZE
446 #define INIT_SIZE ZO_INIT_SIZE
447 #else
448 #define INIT_SIZE VO_INIT_SIZE
449 #endif
450 init_size:              .long INIT_SIZE         # kernel initialization size
451 handover_offset:        .long 0                 # Filled in by build.c
452
453 # End of setup header #####################################################
454
455         .section ".entrytext", "ax"
456 start_of_setup:
457 # Force %es = %ds
458         movw    %ds, %ax
459         movw    %ax, %es
460         cld
461
462 # Apparently some ancient versions of LILO invoked the kernel with %ss != %ds,
463 # which happened to work by accident for the old code.  Recalculate the stack
464 # pointer if %ss is invalid.  Otherwise leave it alone, LOADLIN sets up the
465 # stack behind its own code, so we can't blindly put it directly past the heap.
466
467         movw    %ss, %dx
468         cmpw    %ax, %dx        # %ds == %ss?
469         movw    %sp, %dx
470         je      2f              # -> assume %sp is reasonably set
471
472         # Invalid %ss, make up a new stack
473         movw    $_end, %dx
474         testb   $CAN_USE_HEAP, loadflags
475         jz      1f
476         movw    heap_end_ptr, %dx
477 1:      addw    $STACK_SIZE, %dx
478         jnc     2f
479         xorw    %dx, %dx        # Prevent wraparound
480
481 2:      # Now %dx should point to the end of our stack space
482         andw    $~3, %dx        # dword align (might as well...)
483         jnz     3f
484         movw    $0xfffc, %dx    # Make sure we're not zero
485 3:      movw    %ax, %ss
486         movzwl  %dx, %esp       # Clear upper half of %esp
487         sti                     # Now we should have a working stack
488
489 # We will have entered with %cs = %ds+0x20, normalize %cs so
490 # it is on par with the other segments.
491         pushw   %ds
492         pushw   $6f
493         lretw
494 6:
495
496 # Check signature at end of setup
497         cmpl    $0x5a5aaa55, setup_sig
498         jne     setup_bad
499
500 # Zero the bss
501         movw    $__bss_start, %di
502         movw    $_end+3, %cx
503         xorl    %eax, %eax
504         subw    %di, %cx
505         shrw    $2, %cx
506         rep; stosl
507
508 # Jump to C code (should not return)
509         calll   main
510
511 # Setup corrupt somehow...
512 setup_bad:
513         movl    $setup_corrupt, %eax
514         calll   puts
515         # Fall through...
516
517         .globl  die
518         .type   die, @function
519 die:
520         hlt
521         jmp     die
522
523         .size   die, .-die
524
525         .section ".initdata", "a"
526 setup_corrupt:
527         .byte   7
528         .string "No setup signature found...\n"