blob: e835b4eea70be85d0b9fac4f846fdd55becbf189 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 *
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 */
8
9.text
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/threads.h>
Sam Ravnborg8b2f7ff2008-01-30 13:33:28 +010011#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/linkage.h>
13#include <asm/segment.h>
14#include <asm/page.h>
15#include <asm/pgtable.h>
16#include <asm/desc.h>
17#include <asm/cache.h>
18#include <asm/thread_info.h>
Sam Ravnborg86feeaa2005-09-09 19:28:28 +020019#include <asm/asm-offsets.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <asm/setup.h>
Ian Campbell551889a2008-02-09 23:24:09 +010021#include <asm/processor-flags.h>
22
23/* Physical address */
24#define pa(X) ((X) - __PAGE_OFFSET)
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
26/*
27 * References to members of the new_cpu_data structure.
28 */
29
30#define X86 new_cpu_data+CPUINFO_x86
31#define X86_VENDOR new_cpu_data+CPUINFO_x86_vendor
32#define X86_MODEL new_cpu_data+CPUINFO_x86_model
33#define X86_MASK new_cpu_data+CPUINFO_x86_mask
34#define X86_HARD_MATH new_cpu_data+CPUINFO_hard_math
35#define X86_CPUID new_cpu_data+CPUINFO_cpuid_level
36#define X86_CAPABILITY new_cpu_data+CPUINFO_x86_capability
37#define X86_VENDOR_ID new_cpu_data+CPUINFO_x86_vendor_id
38
39/*
40 * This is how much memory *in addition to the memory covered up to
Jeremy Fitzhardinge9ce8c2e2007-05-02 19:27:16 +020041 * and including _end* we need mapped initially.
42 * We need:
43 * - one bit for each possible page, but only in low memory, which means
44 * 2^32/4096/8 = 128K worst case (4G/4G split.)
45 * - enough space to map all low memory, which means
46 * (2^32/4096) / 1024 pages (worst case, non PAE)
47 * (2^32/4096) / 512 + 4 pages (worst case for PAE)
48 * - a few pages for allocator use before the kernel pagetable has
49 * been set up
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 *
51 * Modulo rounding, each megabyte assigned here requires a kilobyte of
52 * memory, which is currently unreclaimed.
53 *
54 * This should be a multiple of a page.
55 */
Jeremy Fitzhardinge9ce8c2e2007-05-02 19:27:16 +020056LOW_PAGES = 1<<(32-PAGE_SHIFT_asm)
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
Ingo Molnar1e3e1972007-10-17 18:04:34 +020058/*
59 * To preserve the DMA pool in PAGEALLOC kernels, we'll allocate
60 * pagetables from above the 16MB DMA limit, so we'll have to set
61 * up pagetables 16MB more (worst-case):
62 */
63#ifdef CONFIG_DEBUG_PAGEALLOC
64LOW_PAGES = LOW_PAGES + 0x1000000
65#endif
66
Jeremy Fitzhardinge9ce8c2e2007-05-02 19:27:16 +020067#if PTRS_PER_PMD > 1
68PAGE_TABLE_SIZE = (LOW_PAGES / PTRS_PER_PMD) + PTRS_PER_PGD
69#else
70PAGE_TABLE_SIZE = (LOW_PAGES / PTRS_PER_PGD)
71#endif
72BOOTBITMAP_SIZE = LOW_PAGES / 8
73ALLOCATOR_SLOP = 4
74
75INIT_MAP_BEYOND_END = BOOTBITMAP_SIZE + (PAGE_TABLE_SIZE + ALLOCATOR_SLOP)*PAGE_SIZE_asm
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
77/*
78 * 32-bit kernel entrypoint; only used by the boot CPU. On entry,
79 * %esi points to the real-mode code as a 32-bit pointer.
80 * CS and DS must be 4 GB flat segments, but we don't depend on
81 * any particular GDT layout, because we load our own as soon as we
82 * can.
83 */
Vivek Goyalf8657e12007-02-13 13:26:22 +010084.section .text.head,"ax",@progbits
Linus Torvalds1da177e2005-04-16 15:20:36 -070085ENTRY(startup_32)
Rusty Russella24e7852007-10-21 16:41:35 -070086 /* test KEEP_SEGMENTS flag to see if the bootloader is asking
87 us to not reload segments */
88 testb $(1<<6), BP_loadflags(%esi)
89 jnz 2f
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
91/*
92 * Set segments to known values.
93 */
Ian Campbell551889a2008-02-09 23:24:09 +010094 lgdt pa(boot_gdt_descr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 movl $(__BOOT_DS),%eax
96 movl %eax,%ds
97 movl %eax,%es
98 movl %eax,%fs
99 movl %eax,%gs
Rusty Russella24e7852007-10-21 16:41:35 -07001002:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101
102/*
103 * Clear BSS first so that there are no surprises...
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 */
Rusty Russella24e7852007-10-21 16:41:35 -0700105 cld
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 xorl %eax,%eax
Ian Campbell551889a2008-02-09 23:24:09 +0100107 movl $pa(__bss_start),%edi
108 movl $pa(__bss_stop),%ecx
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 subl %edi,%ecx
110 shrl $2,%ecx
111 rep ; stosl
Vivek Goyal484b90c2005-09-03 15:56:31 -0700112/*
113 * Copy bootup parameters out of the way.
114 * Note: %esi still has the pointer to the real-mode data.
115 * With the kexec as boot loader, parameter segment might be loaded beyond
116 * kernel image and might not even be addressable by early boot page tables.
117 * (kexec on panic case). Hence copy out the parameters before initializing
118 * page tables.
119 */
Ian Campbell551889a2008-02-09 23:24:09 +0100120 movl $pa(boot_params),%edi
Vivek Goyal484b90c2005-09-03 15:56:31 -0700121 movl $(PARAM_SIZE/4),%ecx
122 cld
123 rep
124 movsl
Ian Campbell551889a2008-02-09 23:24:09 +0100125 movl pa(boot_params) + NEW_CL_POINTER,%esi
Vivek Goyal484b90c2005-09-03 15:56:31 -0700126 andl %esi,%esi
H. Peter Anvinfa76dab2007-10-23 22:37:25 +0200127 jz 1f # No comand line
Ian Campbell551889a2008-02-09 23:24:09 +0100128 movl $pa(boot_command_line),%edi
Vivek Goyal484b90c2005-09-03 15:56:31 -0700129 movl $(COMMAND_LINE_SIZE/4),%ecx
130 rep
131 movsl
1321:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133
Rusty Russella24e7852007-10-21 16:41:35 -0700134#ifdef CONFIG_PARAVIRT
Ian Campbell551889a2008-02-09 23:24:09 +0100135 /* This is can only trip for a broken bootloader... */
136 cmpw $0x207, pa(boot_params + BP_version)
Rusty Russella24e7852007-10-21 16:41:35 -0700137 jb default_entry
138
139 /* Paravirt-compatible boot parameters. Look to see what architecture
140 we're booting under. */
Ian Campbell551889a2008-02-09 23:24:09 +0100141 movl pa(boot_params + BP_hardware_subarch), %eax
Rusty Russella24e7852007-10-21 16:41:35 -0700142 cmpl $num_subarch_entries, %eax
143 jae bad_subarch
144
Ian Campbell551889a2008-02-09 23:24:09 +0100145 movl pa(subarch_entries)(,%eax,4), %eax
Rusty Russella24e7852007-10-21 16:41:35 -0700146 subl $__PAGE_OFFSET, %eax
147 jmp *%eax
148
149bad_subarch:
150WEAK(lguest_entry)
151WEAK(xen_entry)
152 /* Unknown implementation; there's really
153 nothing we can do at this point. */
154 ud2a
Sam Ravnborg8b2f7ff2008-01-30 13:33:28 +0100155
156 __INITDATA
157
Rusty Russella24e7852007-10-21 16:41:35 -0700158subarch_entries:
159 .long default_entry /* normal x86/PC */
160 .long lguest_entry /* lguest hypervisor */
161 .long xen_entry /* Xen hypervisor */
162num_subarch_entries = (. - subarch_entries) / 4
163.previous
164#endif /* CONFIG_PARAVIRT */
165
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166/*
167 * Initialize page tables. This creates a PDE and a set of page
168 * tables, which are located immediately beyond _end. The variable
169 * init_pg_tables_end is set up to point to the first "safe" location.
170 * Mappings are created both at virtual address 0 (identity mapping)
171 * and PAGE_OFFSET for up to _end+sizeof(page tables)+INIT_MAP_BEYOND_END.
172 *
Ian Campbell551889a2008-02-09 23:24:09 +0100173 * Note that the stack is not yet set up!
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 */
Rusty Russella24e7852007-10-21 16:41:35 -0700175default_entry:
Ian Campbell551889a2008-02-09 23:24:09 +0100176#ifdef CONFIG_X86_PAE
177
178 /*
179 * In PAE mode swapper_pg_dir is statically defined to contain enough
180 * entries to cover the VMSPLIT option (that is the top 1, 2 or 3
181 * entries). The identity mapping is handled by pointing two PGD
182 * entries to the first kernel PMD.
183 *
184 * Note the upper half of each PMD or PTE are always zero at
185 * this stage.
186 */
187
Joe Korty86b2b702008-06-02 17:21:06 -0400188#define KPMDS (((-__PAGE_OFFSET) >> 30) & 3) /* Number of kernel PMDs */
Ian Campbell551889a2008-02-09 23:24:09 +0100189
190 xorl %ebx,%ebx /* %ebx is kept at zero */
191
192 movl $pa(pg0), %edi
Yinghai Luf0d43102008-05-29 12:56:36 -0700193 movl %edi, pa(init_pg_tables_start)
Ian Campbell551889a2008-02-09 23:24:09 +0100194 movl $pa(swapper_pg_pmd), %edx
Suresh Siddhab2bc2732008-09-23 14:00:36 -0700195 movl $PTE_IDENT_ATTR, %eax
Linus Torvalds1da177e2005-04-16 15:20:36 -070019610:
Suresh Siddhab2bc2732008-09-23 14:00:36 -0700197 leal PDE_IDENT_ATTR(%edi),%ecx /* Create PMD entry */
Ian Campbell551889a2008-02-09 23:24:09 +0100198 movl %ecx,(%edx) /* Store PMD entry */
199 /* Upper half already zero */
200 addl $8,%edx
201 movl $512,%ecx
20211:
203 stosl
204 xchgl %eax,%ebx
205 stosl
206 xchgl %eax,%ebx
207 addl $0x1000,%eax
208 loop 11b
209
210 /*
211 * End condition: we must map up to and including INIT_MAP_BEYOND_END
212 * bytes beyond the end of our own page tables.
213 */
Suresh Siddhab2bc2732008-09-23 14:00:36 -0700214 leal (INIT_MAP_BEYOND_END+PTE_IDENT_ATTR)(%edi),%ebp
Ian Campbell551889a2008-02-09 23:24:09 +0100215 cmpl %ebp,%eax
216 jb 10b
2171:
218 movl %edi,pa(init_pg_tables_end)
Yinghai Lu6af61a72008-06-01 23:53:50 -0700219 shrl $12, %eax
220 movl %eax, pa(max_pfn_mapped)
Ian Campbell551889a2008-02-09 23:24:09 +0100221
222 /* Do early initialization of the fixmap area */
Suresh Siddhab2bc2732008-09-23 14:00:36 -0700223 movl $pa(swapper_pg_fixmap)+PDE_IDENT_ATTR,%eax
Ian Campbell551889a2008-02-09 23:24:09 +0100224 movl %eax,pa(swapper_pg_pmd+0x1000*KPMDS-8)
225#else /* Not PAE */
226
227page_pde_offset = (__PAGE_OFFSET >> 20);
228
229 movl $pa(pg0), %edi
Yinghai Luf0d43102008-05-29 12:56:36 -0700230 movl %edi, pa(init_pg_tables_start)
Ian Campbell551889a2008-02-09 23:24:09 +0100231 movl $pa(swapper_pg_dir), %edx
Suresh Siddhab2bc2732008-09-23 14:00:36 -0700232 movl $PTE_IDENT_ATTR, %eax
Ian Campbell551889a2008-02-09 23:24:09 +010023310:
Suresh Siddhab2bc2732008-09-23 14:00:36 -0700234 leal PDE_IDENT_ATTR(%edi),%ecx /* Create PDE entry */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 movl %ecx,(%edx) /* Store identity PDE entry */
236 movl %ecx,page_pde_offset(%edx) /* Store kernel PDE entry */
237 addl $4,%edx
238 movl $1024, %ecx
23911:
240 stosl
241 addl $0x1000,%eax
242 loop 11b
Ian Campbell551889a2008-02-09 23:24:09 +0100243 /*
244 * End condition: we must map up to and including INIT_MAP_BEYOND_END
245 * bytes beyond the end of our own page tables; the +0x007 is
246 * the attribute bits
247 */
Suresh Siddhab2bc2732008-09-23 14:00:36 -0700248 leal (INIT_MAP_BEYOND_END+PTE_IDENT_ATTR)(%edi),%ebp
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 cmpl %ebp,%eax
250 jb 10b
Ian Campbell551889a2008-02-09 23:24:09 +0100251 movl %edi,pa(init_pg_tables_end)
Yinghai Lu6af61a72008-06-01 23:53:50 -0700252 shrl $12, %eax
253 movl %eax, pa(max_pfn_mapped)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254
Ian Campbell551889a2008-02-09 23:24:09 +0100255 /* Do early initialization of the fixmap area */
Suresh Siddhab2bc2732008-09-23 14:00:36 -0700256 movl $pa(swapper_pg_fixmap)+PDE_IDENT_ATTR,%eax
Ian Campbell551889a2008-02-09 23:24:09 +0100257 movl %eax,pa(swapper_pg_dir+0xffc)
258#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 jmp 3f
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260/*
261 * Non-boot CPU entry point; entered from trampoline.S
262 * We can't lgdt here, because lgdt itself uses a data segment, but
Sebastien Dugue52de74d2007-05-02 19:27:10 +0200263 * we know the trampoline has already loaded the boot_gdt for us.
Vivek Goyalf8657e12007-02-13 13:26:22 +0100264 *
265 * If cpu hotplug is not supported then this code can go in init section
266 * which will be freed later
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 */
Vivek Goyalf8657e12007-02-13 13:26:22 +0100268
Andi Kleen5fe44862007-08-10 22:31:10 +0200269#ifndef CONFIG_HOTPLUG_CPU
Vivek Goyalf8657e12007-02-13 13:26:22 +0100270.section .init.text,"ax",@progbits
271#endif
272
273#ifdef CONFIG_SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274ENTRY(startup_32_smp)
275 cld
276 movl $(__BOOT_DS),%eax
277 movl %eax,%ds
278 movl %eax,%es
279 movl %eax,%fs
280 movl %eax,%gs
Ian Campbell5756dd52008-01-30 13:33:27 +0100281#endif /* CONFIG_SMP */
2823:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283
284/*
285 * New page tables may be in 4Mbyte page mode and may
286 * be using the global pages.
287 *
288 * NOTE! If we are on a 486 we may have no cr4 at all!
289 * So we do not try to touch it unless we really have
290 * some bits in it to set. This won't work if the BSP
291 * implements cr4 but this AP does not -- very unlikely
292 * but be warned! The same applies to the pse feature
293 * if not equally supported. --macro
294 *
295 * NOTE! We have to correct for the fact that we're
296 * not yet offset PAGE_OFFSET..
297 */
Ian Campbell551889a2008-02-09 23:24:09 +0100298#define cr4_bits pa(mmu_cr4_features)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 movl cr4_bits,%edx
300 andl %edx,%edx
301 jz 6f
302 movl %cr4,%eax # Turn on paging options (PSE,PAE,..)
303 orl %edx,%eax
304 movl %eax,%cr4
305
306 btl $5, %eax # check if PAE is enabled
307 jnc 6f
308
309 /* Check if extended functions are implemented */
310 movl $0x80000000, %eax
311 cpuid
312 cmpl $0x80000000, %eax
313 jbe 6f
314 mov $0x80000001, %eax
315 cpuid
316 /* Execute Disable bit supported? */
317 btl $20, %edx
318 jnc 6f
319
320 /* Setup EFER (Extended Feature Enable Register) */
321 movl $0xc0000080, %ecx
322 rdmsr
323
324 btsl $11, %eax
325 /* Make changes effective */
326 wrmsr
327
3286:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329
330/*
331 * Enable paging
332 */
Ian Campbell551889a2008-02-09 23:24:09 +0100333 movl $pa(swapper_pg_dir),%eax
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 movl %eax,%cr3 /* set the page table pointer.. */
335 movl %cr0,%eax
Ian Campbell551889a2008-02-09 23:24:09 +0100336 orl $X86_CR0_PG,%eax
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 movl %eax,%cr0 /* ..and set paging (PG) bit */
338 ljmp $__BOOT_CS,$1f /* Clear prefetch and normalize %eip */
3391:
340 /* Set up the stack pointer */
341 lss stack_start,%esp
342
343/*
344 * Initialize eflags. Some BIOS's leave bits like NT set. This would
345 * confuse the debugger if this code is traced.
346 * XXX - best to initialize before switching to protected mode.
347 */
348 pushl $0
349 popfl
350
351#ifdef CONFIG_SMP
Ian Campbell50359502008-01-30 13:33:27 +0100352 cmpb $0, ready
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 jz 1f /* Initial CPU cleans BSS */
354 jmp checkCPUtype
3551:
356#endif /* CONFIG_SMP */
357
358/*
359 * start system 32-bit setup. We need to re-do some of the things done
360 * in 16-bit mode for the "real" operations.
361 */
362 call setup_idt
363
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364checkCPUtype:
365
366 movl $-1,X86_CPUID # -1 for no CPUID initially
367
368/* check if it is 486 or 386. */
369/*
370 * XXX - this does a lot of unnecessary setup. Alignment checks don't
371 * apply at our cpl of 0 and the stack ought to be aligned already, and
372 * we don't need to preserve eflags.
373 */
374
375 movb $3,X86 # at least 386
376 pushfl # push EFLAGS
377 popl %eax # get EFLAGS
378 movl %eax,%ecx # save original EFLAGS
379 xorl $0x240000,%eax # flip AC and ID bits in EFLAGS
380 pushl %eax # copy to EFLAGS
381 popfl # set EFLAGS
382 pushfl # get new EFLAGS
383 popl %eax # put it in eax
384 xorl %ecx,%eax # change in flags
385 pushl %ecx # restore original EFLAGS
386 popfl
387 testl $0x40000,%eax # check if AC bit changed
388 je is386
389
390 movb $4,X86 # at least 486
391 testl $0x200000,%eax # check if ID bit changed
392 je is486
393
394 /* get vendor info */
395 xorl %eax,%eax # call CPUID with 0 -> return vendor ID
396 cpuid
397 movl %eax,X86_CPUID # save CPUID level
398 movl %ebx,X86_VENDOR_ID # lo 4 chars
399 movl %edx,X86_VENDOR_ID+4 # next 4 chars
400 movl %ecx,X86_VENDOR_ID+8 # last 4 chars
401
402 orl %eax,%eax # do we have processor info as well?
403 je is486
404
405 movl $1,%eax # Use the CPUID instruction to get CPU type
406 cpuid
407 movb %al,%cl # save reg for future use
408 andb $0x0f,%ah # mask processor family
409 movb %ah,X86
410 andb $0xf0,%al # mask model
411 shrb $4,%al
412 movb %al,X86_MODEL
413 andb $0x0f,%cl # mask mask revision
414 movb %cl,X86_MASK
415 movl %edx,X86_CAPABILITY
416
417is486: movl $0x50022,%ecx # set AM, WP, NE and MP
418 jmp 2f
419
420is386: movl $2,%ecx # set MP
4212: movl %cr0,%eax
422 andl $0x80000011,%eax # Save PG,PE,ET
423 orl %ecx,%eax
424 movl %eax,%cr0
425
426 call check_x87
Rusty Russell2a57ff12007-02-13 13:26:26 +0100427 lgdt early_gdt_descr
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 lidt idt_descr
429 ljmp $(__KERNEL_CS),$1f
4301: movl $(__KERNEL_DS),%eax # reload all the segment registers
431 movl %eax,%ss # after changing gdt.
Jeremy Fitzhardinge7c3576d2007-05-02 19:27:16 +0200432 movl %eax,%fs # gets reset once there's real percpu
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433
434 movl $(__USER_DS),%eax # DS/ES contains default USER segment
435 movl %eax,%ds
436 movl %eax,%es
437
Jeremy Fitzhardinge464d1a72007-02-13 13:26:20 +0100438 xorl %eax,%eax # Clear GS and LDT
439 movl %eax,%gs
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 lldt %ax
Jeremy Fitzhardingef95d47c2006-12-07 02:14:02 +0100441
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 cld # gcc2 wants the direction flag cleared at all times
Jeremy Fitzhardinge26fd5e02006-10-21 18:37:02 +0200443 pushl $0 # fake return address for unwinder
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444#ifdef CONFIG_SMP
Shaohua Lid92de652005-06-25 14:54:49 -0700445 movb ready, %cl
446 movb $1, ready
Andi Kleen29fe5f32006-08-30 19:37:09 +0200447 cmpb $0,%cl # the first CPU calls start_kernel
Jeremy Fitzhardinge7c3576d2007-05-02 19:27:16 +0200448 je 1f
449 movl $(__KERNEL_PERCPU), %eax
450 movl %eax,%fs # set this cpu's percpu
Glauber Costa3e970472008-05-28 13:01:54 -0300451 movl (stack_start), %esp
Jeremy Fitzhardinge7c3576d2007-05-02 19:27:16 +02004521:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453#endif /* CONFIG_SMP */
Glauber Costae3f77ed2008-05-28 12:57:02 -0300454 jmp *(initial_code)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455
456/*
457 * We depend on ET to be correct. This checks for 287/387.
458 */
459check_x87:
460 movb $0,X86_HARD_MATH
461 clts
462 fninit
463 fstsw %ax
464 cmpb $0,%al
465 je 1f
466 movl %cr0,%eax /* no coprocessor: have to set bits */
467 xorl $4,%eax /* set EM */
468 movl %eax,%cr0
469 ret
470 ALIGN
4711: movb $1,X86_HARD_MATH
472 .byte 0xDB,0xE4 /* fsetpm for 287, ignored by 387 */
473 ret
474
475/*
476 * setup_idt
477 *
478 * sets up a idt with 256 entries pointing to
479 * ignore_int, interrupt gates. It doesn't actually load
480 * idt - that can be done only after paging has been enabled
481 * and the kernel moved to PAGE_OFFSET. Interrupts
482 * are enabled elsewhere, when we can be relatively
483 * sure everything is ok.
484 *
485 * Warning: %esi is live across this function.
486 */
487setup_idt:
488 lea ignore_int,%edx
489 movl $(__KERNEL_CS << 16),%eax
490 movw %dx,%ax /* selector = 0x0010 = cs */
491 movw $0x8E00,%dx /* interrupt gate - dpl=0, present */
492
493 lea idt_table,%edi
494 mov $256,%ecx
495rp_sidt:
496 movl %eax,(%edi)
497 movl %edx,4(%edi)
498 addl $8,%edi
499 dec %ecx
500 jne rp_sidt
Chuck Ebbertec5c0922006-09-26 10:52:39 +0200501
502.macro set_early_handler handler,trapno
503 lea \handler,%edx
504 movl $(__KERNEL_CS << 16),%eax
505 movw %dx,%ax
506 movw $0x8E00,%dx /* interrupt gate - dpl=0, present */
507 lea idt_table,%edi
508 movl %eax,8*\trapno(%edi)
509 movl %edx,8*\trapno+4(%edi)
510.endm
511
512 set_early_handler handler=early_divide_err,trapno=0
513 set_early_handler handler=early_illegal_opcode,trapno=6
514 set_early_handler handler=early_protection_fault,trapno=13
515 set_early_handler handler=early_page_fault,trapno=14
516
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 ret
518
Chuck Ebbertec5c0922006-09-26 10:52:39 +0200519early_divide_err:
520 xor %edx,%edx
521 pushl $0 /* fake errcode */
522 jmp early_fault
523
524early_illegal_opcode:
525 movl $6,%edx
526 pushl $0 /* fake errcode */
527 jmp early_fault
528
529early_protection_fault:
530 movl $13,%edx
531 jmp early_fault
532
533early_page_fault:
534 movl $14,%edx
535 jmp early_fault
536
537early_fault:
538 cld
539#ifdef CONFIG_PRINTK
Ingo Molnar382f64a2007-10-17 18:04:41 +0200540 pusha
Chuck Ebbertec5c0922006-09-26 10:52:39 +0200541 movl $(__KERNEL_DS),%eax
542 movl %eax,%ds
543 movl %eax,%es
544 cmpl $2,early_recursion_flag
545 je hlt_loop
546 incl early_recursion_flag
547 movl %cr2,%eax
548 pushl %eax
549 pushl %edx /* trapno */
550 pushl $fault_msg
551#ifdef CONFIG_EARLY_PRINTK
552 call early_printk
553#else
554 call printk
555#endif
556#endif
Ingo Molnar94878ef2008-01-30 13:33:09 +0100557 call dump_stack
Chuck Ebbertec5c0922006-09-26 10:52:39 +0200558hlt_loop:
559 hlt
560 jmp hlt_loop
561
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562/* This is the default interrupt "handler" :-) */
563 ALIGN
564ignore_int:
565 cld
Matt Mackalld59745c2005-05-01 08:59:02 -0700566#ifdef CONFIG_PRINTK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 pushl %eax
568 pushl %ecx
569 pushl %edx
570 pushl %es
571 pushl %ds
572 movl $(__KERNEL_DS),%eax
573 movl %eax,%ds
574 movl %eax,%es
Chuck Ebbertec5c0922006-09-26 10:52:39 +0200575 cmpl $2,early_recursion_flag
576 je hlt_loop
577 incl early_recursion_flag
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 pushl 16(%esp)
579 pushl 24(%esp)
580 pushl 32(%esp)
581 pushl 40(%esp)
582 pushl $int_msg
Ingo Molnarc0cdf192006-02-11 17:55:56 -0800583#ifdef CONFIG_EARLY_PRINTK
584 call early_printk
585#else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 call printk
Ingo Molnarc0cdf192006-02-11 17:55:56 -0800587#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 addl $(5*4),%esp
589 popl %ds
590 popl %es
591 popl %edx
592 popl %ecx
593 popl %eax
Matt Mackalld59745c2005-05-01 08:59:02 -0700594#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 iret
596
Thomas Gleixner583323b2008-07-27 21:43:11 +0200597.section .cpuinit.data,"wa"
598.align 4
599ENTRY(initial_code)
600 .long i386_start_kernel
601
Vivek Goyalf8657e12007-02-13 13:26:22 +0100602.section .text
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603/*
604 * Real beginning of normal "text" segment
605 */
606ENTRY(stext)
607ENTRY(_stext)
608
609/*
610 * BSS section
611 */
Jeremy Fitzhardinge5ead97c2007-07-17 18:37:04 -0700612.section ".bss.page_aligned","wa"
613 .align PAGE_SIZE_asm
Ian Campbell551889a2008-02-09 23:24:09 +0100614#ifdef CONFIG_X86_PAE
Adrian Bunked2b7e22008-02-22 21:58:37 +0200615swapper_pg_pmd:
Ian Campbell551889a2008-02-09 23:24:09 +0100616 .fill 1024*KPMDS,4,0
617#else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618ENTRY(swapper_pg_dir)
619 .fill 1024,4,0
Ian Campbell551889a2008-02-09 23:24:09 +0100620#endif
Adrian Bunkaa65af3f2008-02-13 23:29:55 +0200621swapper_pg_fixmap:
Eric W. Bidermanb1c931e2007-07-15 23:37:28 -0700622 .fill 1024,4,0
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623ENTRY(empty_zero_page)
624 .fill 4096,1,0
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625/*
626 * This starts the data section.
627 */
Ian Campbell551889a2008-02-09 23:24:09 +0100628#ifdef CONFIG_X86_PAE
629.section ".data.page_aligned","wa"
630 /* Page-aligned for the benefit of paravirt? */
631 .align PAGE_SIZE_asm
632ENTRY(swapper_pg_dir)
Suresh Siddhab2bc2732008-09-23 14:00:36 -0700633 .long pa(swapper_pg_pmd+PGD_IDENT_ATTR),0 /* low identity map */
Ian Campbell551889a2008-02-09 23:24:09 +0100634# if KPMDS == 3
Suresh Siddhab2bc2732008-09-23 14:00:36 -0700635 .long pa(swapper_pg_pmd+PGD_IDENT_ATTR),0
636 .long pa(swapper_pg_pmd+PGD_IDENT_ATTR+0x1000),0
637 .long pa(swapper_pg_pmd+PGD_IDENT_ATTR+0x2000),0
Ian Campbell551889a2008-02-09 23:24:09 +0100638# elif KPMDS == 2
639 .long 0,0
Suresh Siddhab2bc2732008-09-23 14:00:36 -0700640 .long pa(swapper_pg_pmd+PGD_IDENT_ATTR),0
641 .long pa(swapper_pg_pmd+PGD_IDENT_ATTR+0x1000),0
Ian Campbell551889a2008-02-09 23:24:09 +0100642# elif KPMDS == 1
643 .long 0,0
644 .long 0,0
Suresh Siddhab2bc2732008-09-23 14:00:36 -0700645 .long pa(swapper_pg_pmd+PGD_IDENT_ATTR),0
Ian Campbell551889a2008-02-09 23:24:09 +0100646# else
647# error "Kernel PMDs should be 1, 2 or 3"
648# endif
649 .align PAGE_SIZE_asm /* needs to be page-sized too */
650#endif
651
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652.data
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653ENTRY(stack_start)
654 .long init_thread_union+THREAD_SIZE
655 .long __BOOT_DS
656
657ready: .byte 0
658
Chuck Ebbertec5c0922006-09-26 10:52:39 +0200659early_recursion_flag:
660 .long 0
661
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662int_msg:
663 .asciz "Unknown interrupt or fault at EIP %p %p %p\n"
664
Chuck Ebbertec5c0922006-09-26 10:52:39 +0200665fault_msg:
Vegard Nossum575ca732008-04-25 21:02:34 +0200666/* fault info: */
667 .ascii "BUG: Int %d: CR2 %p\n"
668/* pusha regs: */
669 .ascii " EDI %p ESI %p EBP %p ESP %p\n"
670 .ascii " EBX %p EDX %p ECX %p EAX %p\n"
671/* fault frame: */
672 .ascii " err %p EIP %p CS %p flg %p\n"
673 .ascii "Stack: %p %p %p %p %p %p %p %p\n"
674 .ascii " %p %p %p %p %p %p %p %p\n"
675 .asciz " %p %p %p %p %p %p %p %p\n"
Chuck Ebbertec5c0922006-09-26 10:52:39 +0200676
Thomas Gleixner97027852007-10-11 11:16:51 +0200677#include "../../x86/xen/xen-head.S"
Jeremy Fitzhardinge5ead97c2007-07-17 18:37:04 -0700678
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679/*
680 * The IDT and GDT 'descriptors' are a strange 48-bit object
681 * only used by the lidt and lgdt instructions. They are not
682 * like usual segment descriptors - they consist of a 16-bit
683 * segment size, and 32-bit linear address value:
684 */
685
686.globl boot_gdt_descr
687.globl idt_descr
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688
689 ALIGN
690# early boot GDT descriptor (must use 1:1 address mapping)
691 .word 0 # 32 bit align gdt_desc.address
692boot_gdt_descr:
693 .word __BOOT_DS+7
Sebastien Dugue52de74d2007-05-02 19:27:10 +0200694 .long boot_gdt - __PAGE_OFFSET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695
696 .word 0 # 32-bit align idt_desc.address
697idt_descr:
698 .word IDT_ENTRIES*8-1 # idt contains 256 entries
699 .long idt_table
700
701# boot GDT descriptor (later on used by CPU#0):
702 .word 0 # 32 bit align gdt_desc.address
Rusty Russell2a57ff12007-02-13 13:26:26 +0100703ENTRY(early_gdt_descr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 .word GDT_ENTRIES*8-1
Jeremy Fitzhardinge7a61d352007-05-02 19:27:15 +0200705 .long per_cpu__gdt_page /* Overwritten for secondary CPUs */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707/*
Sebastien Dugue52de74d2007-05-02 19:27:10 +0200708 * The boot_gdt must mirror the equivalent in setup.S and is
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 * used only for booting.
710 */
711 .align L1_CACHE_BYTES
Sebastien Dugue52de74d2007-05-02 19:27:10 +0200712ENTRY(boot_gdt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 .fill GDT_ENTRY_BOOT_CS,8,0
714 .quad 0x00cf9a000000ffff /* kernel 4GB code at 0x00000000 */
715 .quad 0x00cf92000000ffff /* kernel 4GB data at 0x00000000 */