| blob | c8932c79e78bbaad99c4969a1ea1a0ff2f7f1802 |
1 /*
2 *
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 *
5 * Enhanced CPU detection and feature setting code by Mike Jagdis
6 * and Martin Mares, November 1997.
7 */
9 .text
10 #include <linux/threads.h>
11 #include <linux/init.h>
12 #include <linux/linkage.h>
13 #include <asm/segment.h>
14 #include <asm/page_types.h>
15 #include <asm/pgtable_types.h>
16 #include <asm/cache.h>
17 #include <asm/thread_info.h>
18 #include <asm/asm-offsets.h>
19 #include <asm/setup.h>
20 #include <asm/processor-flags.h>
21 #include <asm/msr-index.h>
22 #include <asm/cpufeature.h>
23 #include <asm/percpu.h>
24 #include <asm/nops.h>
26 /* Physical address */
27 #define pa(X) ((X) - __PAGE_OFFSET)
29 /*
30 * References to members of the new_cpu_data structure.
31 */
33 #define X86 new_cpu_data+CPUINFO_x86
34 #define X86_VENDOR new_cpu_data+CPUINFO_x86_vendor
35 #define X86_MODEL new_cpu_data+CPUINFO_x86_model
36 #define X86_MASK new_cpu_data+CPUINFO_x86_mask
37 #define X86_HARD_MATH new_cpu_data+CPUINFO_hard_math
38 #define X86_CPUID new_cpu_data+CPUINFO_cpuid_level
39 #define X86_CAPABILITY new_cpu_data+CPUINFO_x86_capability
40 #define X86_VENDOR_ID new_cpu_data+CPUINFO_x86_vendor_id
42 /*
43 * This is how much memory in addition to the memory covered up to
44 * and including _end we need mapped initially.
45 * We need:
46 * (KERNEL_IMAGE_SIZE/4096) / 1024 pages (worst case, non PAE)
47 * (KERNEL_IMAGE_SIZE/4096) / 512 + 4 pages (worst case for PAE)
48 *
49 * Modulo rounding, each megabyte assigned here requires a kilobyte of
50 * memory, which is currently unreclaimed.
51 *
52 * This should be a multiple of a page.
53 *
54 * KERNEL_IMAGE_SIZE should be greater than pa(_end)
55 * and small than max_low_pfn, otherwise will waste some page table entries
56 */
58 #if PTRS_PER_PMD > 1
59 #define PAGE_TABLE_SIZE(pages) (((pages) / PTRS_PER_PMD) + PTRS_PER_PGD)
60 #else
61 #define PAGE_TABLE_SIZE(pages) ((pages) / PTRS_PER_PGD)
62 #endif
64 /* Number of possible pages in the lowmem region */
65 LOWMEM_PAGES = (((1<<32) - __PAGE_OFFSET) >> PAGE_SHIFT)
67 /* Enough space to fit pagetables for the low memory linear map */
68 MAPPING_BEYOND_END = PAGE_TABLE_SIZE(LOWMEM_PAGES) << PAGE_SHIFT
70 /*
71 * Worst-case size of the kernel mapping we need to make:
72 * a relocatable kernel can live anywhere in lowmem, so we need to be able
73 * to map all of lowmem.
74 */
75 KERNEL_PAGES = LOWMEM_PAGES
77 INIT_MAP_SIZE = PAGE_TABLE_SIZE(KERNEL_PAGES) * PAGE_SIZE
78 RESERVE_BRK(pagetables, INIT_MAP_SIZE)
80 /*
81 * 32-bit kernel entrypoint; only used by the boot CPU. On entry,
82 * %esi points to the real-mode code as a 32-bit pointer.
83 * CS and DS must be 4 GB flat segments, but we don't depend on
84 * any particular GDT layout, because we load our own as soon as we
85 * can.
86 */
87 __HEAD
88 ENTRY(startup_32)
89 movl pa(stack_start),%ecx
91 /* test KEEP_SEGMENTS flag to see if the bootloader is asking
92 us to not reload segments */
93 testb $(1<<6), BP_loadflags(%esi)
94 jnz 2f
96 /*
97 * Set segments to known values.
98 */
99 lgdt pa(boot_gdt_descr)
100 movl $(__BOOT_DS),%eax
101 movl %eax,%ds
102 movl %eax,%es
103 movl %eax,%fs
104 movl %eax,%gs
105 movl %eax,%ss
106 2:
107 leal -__PAGE_OFFSET(%ecx),%esp
109 /*
110 * Clear BSS first so that there are no surprises...
111 */
112 cld
113 xorl %eax,%eax
114 movl $pa(__bss_start),%edi
115 movl $pa(__bss_stop),%ecx
116 subl %edi,%ecx
117 shrl $2,%ecx
118 rep ; stosl
119 /*
120 * Copy bootup parameters out of the way.
121 * Note: %esi still has the pointer to the real-mode data.
122 * With the kexec as boot loader, parameter segment might be loaded beyond
123 * kernel image and might not even be addressable by early boot page tables.
124 * (kexec on panic case). Hence copy out the parameters before initializing
125 * page tables.
126 */
127 movl $pa(boot_params),%edi
128 movl $(PARAM_SIZE/4),%ecx
129 cld
130 rep
131 movsl
132 movl pa(boot_params) + NEW_CL_POINTER,%esi
133 andl %esi,%esi
134 jz 1f # No command line
135 movl $pa(boot_command_line),%edi
136 movl $(COMMAND_LINE_SIZE/4),%ecx
137 rep
138 movsl
139 1:
141 #ifdef CONFIG_OLPC
142 /* save OFW's pgdir table for later use when calling into OFW */
143 movl %cr3, %eax
144 movl %eax, pa(olpc_ofw_pgd)
145 #endif
147 /*
148 * Initialize page tables. This creates a PDE and a set of page
149 * tables, which are located immediately beyond __brk_base. The variable
150 * _brk_end is set up to point to the first "safe" location.
151 * Mappings are created both at virtual address 0 (identity mapping)
152 * and PAGE_OFFSET for up to _end.
153 */
154 #ifdef CONFIG_X86_PAE
156 /*
157 * In PAE mode initial_page_table is statically defined to contain
158 * enough entries to cover the VMSPLIT option (that is the top 1, 2 or 3
159 * entries). The identity mapping is handled by pointing two PGD entries
160 * to the first kernel PMD.
161 *
162 * Note the upper half of each PMD or PTE are always zero at this stage.
163 */
165 #define KPMDS (((-__PAGE_OFFSET) >> 30) & 3) /* Number of kernel PMDs */
167 xorl %ebx,%ebx /* %ebx is kept at zero */
169 movl $pa(__brk_base), %edi
170 movl $pa(initial_pg_pmd), %edx
171 movl $PTE_IDENT_ATTR, %eax
172 10:
173 leal PDE_IDENT_ATTR(%edi),%ecx /* Create PMD entry */
174 movl %ecx,(%edx) /* Store PMD entry */
175 /* Upper half already zero */
176 addl $8,%edx
177 movl $512,%ecx
178 11:
179 stosl
180 xchgl %eax,%ebx
181 stosl
182 xchgl %eax,%ebx
183 addl $0x1000,%eax
184 loop 11b
186 /*
187 * End condition: we must map up to the end + MAPPING_BEYOND_END.
188 */
189 movl $pa(_end) + MAPPING_BEYOND_END + PTE_IDENT_ATTR, %ebp
190 cmpl %ebp,%eax
191 jb 10b
192 1:
193 addl $__PAGE_OFFSET, %edi
194 movl %edi, pa(_brk_end)
195 shrl $12, %eax
196 movl %eax, pa(max_pfn_mapped)
198 /* Do early initialization of the fixmap area */
199 movl $pa(initial_pg_fixmap)+PDE_IDENT_ATTR,%eax
200 movl %eax,pa(initial_pg_pmd+0x1000*KPMDS-8)
201 #else /* Not PAE */
203 page_pde_offset = (__PAGE_OFFSET >> 20);
205 movl $pa(__brk_base), %edi
206 movl $pa(initial_page_table), %edx
207 movl $PTE_IDENT_ATTR, %eax
208 10:
209 leal PDE_IDENT_ATTR(%edi),%ecx /* Create PDE entry */
210 movl %ecx,(%edx) /* Store identity PDE entry */
211 movl %ecx,page_pde_offset(%edx) /* Store kernel PDE entry */
212 addl $4,%edx
213 movl $1024, %ecx
214 11:
215 stosl
216 addl $0x1000,%eax
217 loop 11b
218 /*
219 * End condition: we must map up to the end + MAPPING_BEYOND_END.
220 */
221 movl $pa(_end) + MAPPING_BEYOND_END + PTE_IDENT_ATTR, %ebp
222 cmpl %ebp,%eax
223 jb 10b
224 addl $__PAGE_OFFSET, %edi
225 movl %edi, pa(_brk_end)
226 shrl $12, %eax
227 movl %eax, pa(max_pfn_mapped)
229 /* Do early initialization of the fixmap area */
230 movl $pa(initial_pg_fixmap)+PDE_IDENT_ATTR,%eax
231 movl %eax,pa(initial_page_table+0xffc)
232 #endif
234 #ifdef CONFIG_PARAVIRT
235 /* This is can only trip for a broken bootloader... */
236 cmpw $0x207, pa(boot_params + BP_version)
237 jb default_entry
239 /* Paravirt-compatible boot parameters. Look to see what architecture
240 we're booting under. */
241 movl pa(boot_params + BP_hardware_subarch), %eax
242 cmpl $num_subarch_entries, %eax
243 jae bad_subarch
245 movl pa(subarch_entries)(,%eax,4), %eax
246 subl $__PAGE_OFFSET, %eax
247 jmp *%eax
249 bad_subarch:
250 WEAK(lguest_entry)
251 WEAK(xen_entry)
252 /* Unknown implementation; there's really
253 nothing we can do at this point. */
254 ud2a
256 __INITDATA
258 subarch_entries:
259 .long default_entry /* normal x86/PC */
260 .long lguest_entry /* lguest hypervisor */
261 .long xen_entry /* Xen hypervisor */
262 .long default_entry /* Moorestown MID */
263 num_subarch_entries = (. - subarch_entries) / 4
264 .previous
265 #else
266 jmp default_entry
267 #endif /* CONFIG_PARAVIRT */
269 #ifdef CONFIG_HOTPLUG_CPU
270 /*
271 * Boot CPU0 entry point. It's called from play_dead(). Everything has been set
272 * up already except stack. We just set up stack here. Then call
273 * start_secondary().
274 */
275 ENTRY(start_cpu0)
276 movl stack_start, %ecx
277 movl %ecx, %esp
278 jmp *(initial_code)
279 ENDPROC(start_cpu0)
280 #endif
282 /*
283 * Non-boot CPU entry point; entered from trampoline.S
284 * We can't lgdt here, because lgdt itself uses a data segment, but
285 * we know the trampoline has already loaded the boot_gdt for us.
286 *
287 * If cpu hotplug is not supported then this code can go in init section
288 * which will be freed later
289 */
290 __CPUINIT
291 ENTRY(startup_32_smp)
292 cld
293 movl $(__BOOT_DS),%eax
294 movl %eax,%ds
295 movl %eax,%es
296 movl %eax,%fs
297 movl %eax,%gs
298 movl pa(stack_start),%ecx
299 movl %eax,%ss
300 leal -__PAGE_OFFSET(%ecx),%esp
302 default_entry:
303 #define CR0_STATE (X86_CR0_PE | X86_CR0_MP | X86_CR0_ET | \
304 X86_CR0_NE | X86_CR0_WP | X86_CR0_AM | \
305 X86_CR0_PG)
306 movl $(CR0_STATE & ~X86_CR0_PG),%eax
307 movl %eax,%cr0
309 /*
310 * New page tables may be in 4Mbyte page mode and may
311 * be using the global pages.
312 *
313 * NOTE! If we are on a 486 we may have no cr4 at all!
314 * Specifically, cr4 exists if and only if CPUID exists
315 * and has flags other than the FPU flag set.
316 */
317 movl $X86_EFLAGS_ID,%ecx
318 pushl %ecx
319 popfl
320 pushfl
321 popl %eax
322 pushl $0
323 popfl
324 pushfl
325 popl %edx
326 xorl %edx,%eax
327 testl %ecx,%eax
328 jz 6f # No ID flag = no CPUID = no CR4
330 movl $1,%eax
331 cpuid
332 andl $~1,%edx # Ignore CPUID.FPU
333 jz 6f # No flags or only CPUID.FPU = no CR4
335 movl pa(mmu_cr4_features),%eax
336 movl %eax,%cr4
338 testb $X86_CR4_PAE, %al # check if PAE is enabled
339 jz 6f
341 /* Check if extended functions are implemented */
342 movl $0x80000000, %eax
343 cpuid
344 /* Value must be in the range 0x80000001 to 0x8000ffff */
345 subl $0x80000001, %eax
346 cmpl $(0x8000ffff-0x80000001), %eax
347 ja 6f
349 /* Clear bogus XD_DISABLE bits */
350 call verify_cpu
352 mov $0x80000001, %eax
353 cpuid
354 /* Execute Disable bit supported? */
355 btl $(X86_FEATURE_NX & 31), %edx
356 jnc 6f
358 /* Setup EFER (Extended Feature Enable Register) */
359 movl $MSR_EFER, %ecx
360 rdmsr
362 btsl $_EFER_NX, %eax
363 /* Make changes effective */
364 wrmsr
366 6:
368 /*
369 * Enable paging
370 */
371 movl $pa(initial_page_table), %eax
372 movl %eax,%cr3 /* set the page table pointer.. */
373 movl $CR0_STATE,%eax
374 movl %eax,%cr0 /* ..and set paging (PG) bit */
375 ljmp $__BOOT_CS,$1f /* Clear prefetch and normalize %eip */
376 1:
377 /* Shift the stack pointer to a virtual address */
378 addl $__PAGE_OFFSET, %esp
380 /*
381 * Initialize eflags. Some BIOS's leave bits like NT set. This would
382 * confuse the debugger if this code is traced.
383 * XXX - best to initialize before switching to protected mode.
384 */
385 pushl $0
386 popfl
388 /*
389 * start system 32-bit setup. We need to re-do some of the things done
390 * in 16-bit mode for the "real" operations.
391 */
392 movl setup_once_ref,%eax
393 andl %eax,%eax
394 jz 1f # Did we do this already?
395 call *%eax
396 1:
398 /* check if it is 486 or 386. */
399 /*
400 * XXX - this does a lot of unnecessary setup. Alignment checks don't
401 * apply at our cpl of 0 and the stack ought to be aligned already, and
402 * we don't need to preserve eflags.
403 */
404 movl $-1,X86_CPUID # -1 for no CPUID initially
405 movb $3,X86 # at least 386
406 pushfl # push EFLAGS
407 popl %eax # get EFLAGS
408 movl %eax,%ecx # save original EFLAGS
409 xorl $0x240000,%eax # flip AC and ID bits in EFLAGS
410 pushl %eax # copy to EFLAGS
411 popfl # set EFLAGS
412 pushfl # get new EFLAGS
413 popl %eax # put it in eax
414 xorl %ecx,%eax # change in flags
415 pushl %ecx # restore original EFLAGS
416 popfl
417 testl $0x40000,%eax # check if AC bit changed
418 je is386
420 movb $4,X86 # at least 486
421 testl $0x200000,%eax # check if ID bit changed
422 je is486
424 /* get vendor info */
425 xorl %eax,%eax # call CPUID with 0 -> return vendor ID
426 cpuid
427 movl %eax,X86_CPUID # save CPUID level
428 movl %ebx,X86_VENDOR_ID # lo 4 chars
429 movl %edx,X86_VENDOR_ID+4 # next 4 chars
430 movl %ecx,X86_VENDOR_ID+8 # last 4 chars
432 orl %eax,%eax # do we have processor info as well?
433 je is486
435 movl $1,%eax # Use the CPUID instruction to get CPU type
436 cpuid
437 movb %al,%cl # save reg for future use
438 andb $0x0f,%ah # mask processor family
439 movb %ah,X86
440 andb $0xf0,%al # mask model
441 shrb $4,%al
442 movb %al,X86_MODEL
443 andb $0x0f,%cl # mask mask revision
444 movb %cl,X86_MASK
445 movl %edx,X86_CAPABILITY
447 is486: movl $0x50022,%ecx # set AM, WP, NE and MP
448 jmp 2f
450 is386: movl $2,%ecx # set MP
451 2: movl %cr0,%eax
452 andl $0x80000011,%eax # Save PG,PE,ET
453 orl %ecx,%eax
454 movl %eax,%cr0
456 call check_x87
457 lgdt early_gdt_descr
458 lidt idt_descr
459 ljmp $(__KERNEL_CS),$1f
460 1: movl $(__KERNEL_DS),%eax # reload all the segment registers
461 movl %eax,%ss # after changing gdt.
463 movl $(__USER_DS),%eax # DS/ES contains default USER segment
464 movl %eax,%ds
465 movl %eax,%es
467 movl $(__KERNEL_PERCPU), %eax
468 movl %eax,%fs # set this cpu's percpu
470 movl $(__KERNEL_STACK_CANARY),%eax
471 movl %eax,%gs
473 xorl %eax,%eax # Clear LDT
474 lldt %ax
476 cld # gcc2 wants the direction flag cleared at all times
477 pushl $0 # fake return address for unwinder
478 jmp *(initial_code)
480 /*
481 * We depend on ET to be correct. This checks for 287/387.
482 */
483 check_x87:
484 movb $0,X86_HARD_MATH
485 clts
486 fninit
487 fstsw %ax
488 cmpb $0,%al
489 je 1f
490 movl %cr0,%eax /* no coprocessor: have to set bits */
491 xorl $4,%eax /* set EM */
492 movl %eax,%cr0
493 ret
494 ALIGN
495 1: movb $1,X86_HARD_MATH
496 .byte 0xDB,0xE4 /* fsetpm for 287, ignored by 387 */
497 ret
500 #include "verify_cpu.S"
502 /*
503 * setup_once
504 *
505 * The setup work we only want to run on the BSP.
506 *
507 * Warning: %esi is live across this function.
508 */
509 __INIT
510 setup_once:
511 /*
512 * Set up a idt with 256 entries pointing to ignore_int,
513 * interrupt gates. It doesn't actually load idt - that needs
514 * to be done on each CPU. Interrupts are enabled elsewhere,
515 * when we can be relatively sure everything is ok.
516 */
518 movl $idt_table,%edi
519 movl $early_idt_handlers,%eax
520 movl $NUM_EXCEPTION_VECTORS,%ecx
521 1:
522 movl %eax,(%edi)
523 movl %eax,4(%edi)
524 /* interrupt gate, dpl=0, present */
525 movl $(0x8E000000 + __KERNEL_CS),2(%edi)
526 addl $9,%eax
527 addl $8,%edi
528 loop 1b
530 movl $256 - NUM_EXCEPTION_VECTORS,%ecx
531 movl $ignore_int,%edx
532 movl $(__KERNEL_CS << 16),%eax
533 movw %dx,%ax /* selector = 0x0010 = cs */
534 movw $0x8E00,%dx /* interrupt gate - dpl=0, present */
535 2:
536 movl %eax,(%edi)
537 movl %edx,4(%edi)
538 addl $8,%edi
539 loop 2b
541 #ifdef CONFIG_CC_STACKPROTECTOR
542 /*
543 * Configure the stack canary. The linker can't handle this by
544 * relocation. Manually set base address in stack canary
545 * segment descriptor.
546 */
547 movl $gdt_page,%eax
548 movl $stack_canary,%ecx
549 movw %cx, 8 * GDT_ENTRY_STACK_CANARY + 2(%eax)
550 shrl $16, %ecx
551 movb %cl, 8 * GDT_ENTRY_STACK_CANARY + 4(%eax)
552 movb %ch, 8 * GDT_ENTRY_STACK_CANARY + 7(%eax)
553 #endif
555 andl $0,setup_once_ref /* Once is enough, thanks */
556 ret
558 ENTRY(early_idt_handlers)
559 # 36(%esp) %eflags
560 # 32(%esp) %cs
561 # 28(%esp) %eip
562 # 24(%rsp) error code
563 i = 0
564 .rept NUM_EXCEPTION_VECTORS
565 .if (EXCEPTION_ERRCODE_MASK >> i) & 1
566 ASM_NOP2
567 .else
568 pushl $0 # Dummy error code, to make stack frame uniform
569 .endif
570 pushl $i # 20(%esp) Vector number
571 jmp early_idt_handler
572 i = i + 1
573 .endr
574 ENDPROC(early_idt_handlers)
576 /* This is global to keep gas from relaxing the jumps */
577 ENTRY(early_idt_handler)
578 cld
579 cmpl $2,%ss:early_recursion_flag
580 je hlt_loop
581 incl %ss:early_recursion_flag
583 push %eax # 16(%esp)
584 push %ecx # 12(%esp)
585 push %edx # 8(%esp)
586 push %ds # 4(%esp)
587 push %es # 0(%esp)
588 movl $(__KERNEL_DS),%eax
589 movl %eax,%ds
590 movl %eax,%es
592 cmpl $(__KERNEL_CS),32(%esp)
593 jne 10f
595 leal 28(%esp),%eax # Pointer to %eip
596 call early_fixup_exception
597 andl %eax,%eax
598 jnz ex_entry /* found an exception entry */
600 10:
601 #ifdef CONFIG_PRINTK
602 xorl %eax,%eax
603 movw %ax,2(%esp) /* clean up the segment values on some cpus */
604 movw %ax,6(%esp)
605 movw %ax,34(%esp)
606 leal 40(%esp),%eax
607 pushl %eax /* %esp before the exception */
608 pushl %ebx
609 pushl %ebp
610 pushl %esi
611 pushl %edi
612 movl %cr2,%eax
613 pushl %eax
614 pushl (20+6*4)(%esp) /* trapno */
615 pushl $fault_msg
616 call printk
617 #endif
618 call dump_stack
619 hlt_loop:
620 hlt
621 jmp hlt_loop
623 ex_entry:
624 pop %es
625 pop %ds
626 pop %edx
627 pop %ecx
628 pop %eax
629 addl $8,%esp /* drop vector number and error code */
630 decl %ss:early_recursion_flag
631 iret
632 ENDPROC(early_idt_handler)
634 /* This is the default interrupt "handler" :-) */
635 ALIGN
636 ignore_int:
637 cld
638 #ifdef CONFIG_PRINTK
639 pushl %eax
640 pushl %ecx
641 pushl %edx
642 pushl %es
643 pushl %ds
644 movl $(__KERNEL_DS),%eax
645 movl %eax,%ds
646 movl %eax,%es
647 cmpl $2,early_recursion_flag
648 je hlt_loop
649 incl early_recursion_flag
650 pushl 16(%esp)
651 pushl 24(%esp)
652 pushl 32(%esp)
653 pushl 40(%esp)
654 pushl $int_msg
655 call printk
657 call dump_stack
659 addl $(5*4),%esp
660 popl %ds
661 popl %es
662 popl %edx
663 popl %ecx
664 popl %eax
665 #endif
666 iret
667 ENDPROC(ignore_int)
668 __INITDATA
669 .align 4
670 early_recursion_flag:
671 .long 0
673 __REFDATA
674 .align 4
675 ENTRY(initial_code)
676 .long i386_start_kernel
677 ENTRY(setup_once_ref)
678 .long setup_once
680 /*
681 * BSS section
682 */
683 __PAGE_ALIGNED_BSS
684 .align PAGE_SIZE
685 #ifdef CONFIG_X86_PAE
686 initial_pg_pmd:
687 .fill 1024*KPMDS,4,0
688 #else
689 ENTRY(initial_page_table)
690 .fill 1024,4,0
691 #endif
692 initial_pg_fixmap:
693 .fill 1024,4,0
694 ENTRY(empty_zero_page)
695 .fill 4096,1,0
696 ENTRY(swapper_pg_dir)
697 .fill 1024,4,0
699 /*
700 * This starts the data section.
701 */
702 #ifdef CONFIG_X86_PAE
703 __PAGE_ALIGNED_DATA
704 /* Page-aligned for the benefit of paravirt? */
705 .align PAGE_SIZE
706 ENTRY(initial_page_table)
707 .long pa(initial_pg_pmd+PGD_IDENT_ATTR),0 /* low identity map */
708 # if KPMDS == 3
709 .long pa(initial_pg_pmd+PGD_IDENT_ATTR),0
710 .long pa(initial_pg_pmd+PGD_IDENT_ATTR+0x1000),0
711 .long pa(initial_pg_pmd+PGD_IDENT_ATTR+0x2000),0
712 # elif KPMDS == 2
713 .long 0,0
714 .long pa(initial_pg_pmd+PGD_IDENT_ATTR),0
715 .long pa(initial_pg_pmd+PGD_IDENT_ATTR+0x1000),0
716 # elif KPMDS == 1
717 .long 0,0
718 .long 0,0
719 .long pa(initial_pg_pmd+PGD_IDENT_ATTR),0
720 # else
721 # error "Kernel PMDs should be 1, 2 or 3"
722 # endif
723 .align PAGE_SIZE /* needs to be page-sized too */
724 #endif
726 .data
727 .balign 4
728 ENTRY(stack_start)
729 .long init_thread_union+THREAD_SIZE
731 __INITRODATA
732 int_msg:
733 .asciz "Unknown interrupt or fault at: %p %p %p\n"
735 fault_msg:
736 /* fault info: */
737 .ascii "BUG: Int %d: CR2 %p\n"
738 /* regs pushed in early_idt_handler: */
739 .ascii " EDI %p ESI %p EBP %p EBX %p\n"
740 .ascii " ESP %p ES %p DS %p\n"
741 .ascii " EDX %p ECX %p EAX %p\n"
742 /* fault frame: */
743 .ascii " vec %p err %p EIP %p CS %p flg %p\n"
744 .ascii "Stack: %p %p %p %p %p %p %p %p\n"
745 .ascii " %p %p %p %p %p %p %p %p\n"
746 .asciz " %p %p %p %p %p %p %p %p\n"
748 #include "../../x86/xen/xen-head.S"
750 /*
751 * The IDT and GDT 'descriptors' are a strange 48-bit object
752 * only used by the lidt and lgdt instructions. They are not
753 * like usual segment descriptors - they consist of a 16-bit
754 * segment size, and 32-bit linear address value:
755 */
757 .data
758 .globl boot_gdt_descr
759 .globl idt_descr
761 ALIGN
762 # early boot GDT descriptor (must use 1:1 address mapping)
763 .word 0 # 32 bit align gdt_desc.address
764 boot_gdt_descr:
765 .word __BOOT_DS+7
766 .long boot_gdt - __PAGE_OFFSET
768 .word 0 # 32-bit align idt_desc.address
769 idt_descr:
770 .word IDT_ENTRIES*8-1 # idt contains 256 entries
771 .long idt_table
773 # boot GDT descriptor (later on used by CPU#0):
774 .word 0 # 32 bit align gdt_desc.address
775 ENTRY(early_gdt_descr)
776 .word GDT_ENTRIES*8-1
777 .long gdt_page /* Overwritten for secondary CPUs */
779 /*
780 * The boot_gdt must mirror the equivalent in setup.S and is
781 * used only for booting.
782 */
783 .align L1_CACHE_BYTES
784 ENTRY(boot_gdt)
785 .fill GDT_ENTRY_BOOT_CS,8,0
786 .quad 0x00cf9a000000ffff /* kernel 4GB code at 0x00000000 */
787 .quad 0x00cf92000000ffff /* kernel 4GB data at 0x00000000 */