Annotation of src/sys/arch/i386/i386/locore.S, Revision 1.35
1.34 yamt 1: /* $NetBSD$ */
1.1 fvdl 2:
3: /*-
1.32 mycroft 4: * Copyright (c) 1998, 2000, 2004 The NetBSD Foundation, Inc.
1.1 fvdl 5: * All rights reserved.
6: *
7: * This code is derived from software contributed to The NetBSD Foundation
8: * by Charles M. Hannum.
9: *
10: * Redistribution and use in source and binary forms, with or without
11: * modification, are permitted provided that the following conditions
12: * are met:
13: * 1. Redistributions of source code must retain the above copyright
14: * notice, this list of conditions and the following disclaimer.
15: * 2. Redistributions in binary form must reproduce the above copyright
16: * notice, this list of conditions and the following disclaimer in the
17: * documentation and/or other materials provided with the distribution.
18: * 3. All advertising materials mentioning features or use of this software
19: * must display the following acknowledgement:
20: * This product includes software developed by the NetBSD
21: * Foundation, Inc. and its contributors.
22: * 4. Neither the name of The NetBSD Foundation nor the names of its
23: * contributors may be used to endorse or promote products derived
24: * from this software without specific prior written permission.
25: *
26: * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27: * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28: * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30: * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36: * POSSIBILITY OF SUCH DAMAGE.
37: */
38:
39: /*-
40: * Copyright (c) 1990 The Regents of the University of California.
41: * All rights reserved.
42: *
43: * This code is derived from software contributed to Berkeley by
44: * William Jolitz.
45: *
46: * Redistribution and use in source and binary forms, with or without
47: * modification, are permitted provided that the following conditions
48: * are met:
49: * 1. Redistributions of source code must retain the above copyright
50: * notice, this list of conditions and the following disclaimer.
51: * 2. Redistributions in binary form must reproduce the above copyright
52: * notice, this list of conditions and the following disclaimer in the
53: * documentation and/or other materials provided with the distribution.
1.12 agc 54: * 3. Neither the name of the University nor the names of its contributors
1.1 fvdl 55: * may be used to endorse or promote products derived from this software
56: * without specific prior written permission.
57: *
58: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
59: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
60: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
61: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
62: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
63: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
64: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
65: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
66: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
67: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
68: * SUCH DAMAGE.
69: *
70: * @(#)locore.s 7.3 (Berkeley) 5/13/91
71: */
72:
1.18 christos 73: #include "opt_compat_netbsd.h"
74: #include "opt_compat_oldboot.h"
1.1 fvdl 75: #include "opt_cputype.h"
76: #include "opt_ddb.h"
77: #include "opt_ipkdb.h"
1.18 christos 78: #include "opt_lockdebug.h"
1.1 fvdl 79: #include "opt_multiprocessor.h"
80: #include "opt_realmem.h"
1.18 christos 81: #include "opt_user_ldt.h"
82: #include "opt_vm86.h"
1.1 fvdl 83:
84: #include "npx.h"
85: #include "assym.h"
86: #include "apm.h"
87: #include "lapic.h"
88: #include "ioapic.h"
1.8 fvdl 89: #include "ksyms.h"
1.1 fvdl 90:
91: #include <sys/errno.h>
92: #include <sys/syscall.h>
93:
94: #include <machine/cputypes.h>
95: #include <machine/segments.h>
96: #include <machine/specialreg.h>
97: #include <machine/trap.h>
98: #include <machine/bootinfo.h>
99:
100: #if NLAPIC > 0
101: #include <machine/i82489reg.h>
102: #endif
103:
104: /* LINTSTUB: include <sys/types.h> */
105: /* LINTSTUB: include <machine/cpu.h> */
106: /* LINTSTUB: include <sys/systm.h> */
107:
108: #include <machine/asm.h>
109:
110: #if defined(MULTIPROCESSOR)
1.30 junyoung 111:
1.5 thorpej 112: #define SET_CURLWP(lwp,cpu) \
1.1 fvdl 113: movl CPUVAR(SELF),cpu ; \
1.5 thorpej 114: movl lwp,CPUVAR(CURLWP) ; \
115: movl cpu,L_CPU(lwp)
1.30 junyoung 116:
1.1 fvdl 117: #else
118:
1.5 thorpej 119: #define SET_CURLWP(lwp,tcpu) movl lwp,CPUVAR(CURLWP)
120: #define GET_CURLWP(reg) movl CPUVAR(CURLWP),reg
1.1 fvdl 121:
122: #endif
123:
124: #define SET_CURPCB(reg) movl reg,CPUVAR(CURPCB)
1.24 yamt 125:
1.1 fvdl 126: #define CLEAR_RESCHED(reg) movl reg,CPUVAR(RESCHED)
127:
128: /* XXX temporary kluge; these should not be here */
129: /* Get definitions for IOM_BEGIN, IOM_END, and IOM_SIZE */
130: #include <dev/isa/isareg.h>
131:
132:
133: /* Disallow old names for REALBASEMEM */
134: #ifdef BIOSBASEMEM
135: #error BIOSBASEMEM option deprecated; use REALBASEMEM only if memory size reported by latest boot block is incorrect
136: #endif
137:
138: /* Disallow old names for REALEXTMEM */
139: #ifdef EXTMEM_SIZE
140: #error EXTMEM_SIZE option deprecated; use REALEXTMEM only if memory size reported by latest boot block is incorrect
141: #endif
142: #ifdef BIOSEXTMEM
143: #error BIOSEXTMEM option deprecated; use REALEXTMEM only if memory size reported by latest boot block is incorrect
144: #endif
145:
146: #include <machine/frameasm.h>
147:
148:
149: #ifdef MULTIPROCESSOR
150: #include <machine/i82489reg.h>
151: #endif
1.30 junyoung 152:
1.1 fvdl 153: /*
154: * Initialization
155: */
156: .data
157:
158: .globl _C_LABEL(cpu)
159: .globl _C_LABEL(esym),_C_LABEL(boothowto)
160: .globl _C_LABEL(bootinfo),_C_LABEL(atdevbase)
161: #ifdef COMPAT_OLDBOOT
162: .globl _C_LABEL(bootdev)
163: #endif
1.31 junyoung 164: .globl _C_LABEL(proc0paddr),_C_LABEL(PDPpaddr)
1.1 fvdl 165: .globl _C_LABEL(biosbasemem),_C_LABEL(biosextmem)
166: .globl _C_LABEL(gdt)
167: #ifdef I586_CPU
168: .globl _C_LABEL(idt)
169: #endif
1.30 junyoung 170: .globl _C_LABEL(lapic_tpr)
171:
1.1 fvdl 172: #if NLAPIC > 0
173: #ifdef __ELF__
1.7 thorpej 174: .align PAGE_SIZE
1.1 fvdl 175: #else
176: .align 12
177: #endif
178: .globl _C_LABEL(local_apic), _C_LABEL(lapic_id)
179: _C_LABEL(local_apic):
180: .space LAPIC_ID
1.30 junyoung 181: _C_LABEL(lapic_id):
1.1 fvdl 182: .long 0x00000000
183: .space LAPIC_TPRI-(LAPIC_ID+4)
1.30 junyoung 184: _C_LABEL(lapic_tpr):
1.1 fvdl 185: .space LAPIC_PPRI-LAPIC_TPRI
1.30 junyoung 186: _C_LABEL(lapic_ppr):
1.1 fvdl 187: .space LAPIC_ISR-LAPIC_PPRI
188: _C_LABEL(lapic_isr):
1.7 thorpej 189: .space PAGE_SIZE-LAPIC_ISR
1.1 fvdl 190: #else
1.30 junyoung 191: _C_LABEL(lapic_tpr):
1.1 fvdl 192: .long 0
193: #endif
1.30 junyoung 194:
1.1 fvdl 195:
196: _C_LABEL(cpu): .long 0 # are we 386, 386sx, or 486,
197: # or Pentium, or..
198: _C_LABEL(esym): .long 0 # ptr to end of syms
199: _C_LABEL(atdevbase): .long 0 # location of start of iomem in virtual
200: _C_LABEL(proc0paddr): .long 0
1.31 junyoung 201: _C_LABEL(PDPpaddr): .long 0 # paddr of PDP, for libkvm
1.1 fvdl 202: #ifndef REALBASEMEM
203: _C_LABEL(biosbasemem): .long 0 # base memory reported by BIOS
204: #else
205: _C_LABEL(biosbasemem): .long REALBASEMEM
206: #endif
207: #ifndef REALEXTMEM
208: _C_LABEL(biosextmem): .long 0 # extended memory reported by BIOS
209: #else
210: _C_LABEL(biosextmem): .long REALEXTMEM
211: #endif
1.30 junyoung 212:
1.1 fvdl 213: .space 512
214: tmpstk:
215:
216:
1.35 ! yamt 217: #define _RELOC(x) ((x) - KERNBASE)
1.1 fvdl 218: #define RELOC(x) _RELOC(_C_LABEL(x))
219:
220: .text
221: .globl _C_LABEL(kernel_text)
222: .set _C_LABEL(kernel_text),KERNTEXTOFF
223:
224: .globl start
225: start: movw $0x1234,0x472 # warm boot
226:
227: /*
228: * Load parameters from stack
229: * (howto, [bootdev], bootinfo, esym, basemem, extmem).
230: */
231: movl 4(%esp),%eax
232: movl %eax,RELOC(boothowto)
233: #ifdef COMPAT_OLDBOOT
234: movl 8(%esp),%eax
235: movl %eax,RELOC(bootdev)
236: #endif
237: movl 12(%esp),%eax
238:
239: testl %eax, %eax
240: jz 1f
241: movl (%eax), %ebx /* number of entries */
242: movl $RELOC(bootinfo), %edi
243: movl %ebx, (%edi)
244: addl $4, %edi
245: 2:
246: testl %ebx, %ebx
247: jz 1f
248: addl $4, %eax
249: movl (%eax), %ecx /* address of entry */
250: pushl %eax
251: pushl (%ecx) /* len */
252: pushl %ecx
253: pushl %edi
254: addl (%ecx), %edi /* update dest pointer */
255: cmpl $_RELOC(_C_LABEL(bootinfo) + BOOTINFO_MAXSIZE), %edi
256: jg 2f
257: call _C_LABEL(memcpy)
258: addl $12, %esp
259: popl %eax
260: subl $1, %ebx
261: jmp 2b
262: 2: /* cleanup for overflow case */
263: addl $16, %esp
264: movl $RELOC(bootinfo), %edi
265: subl %ebx, (%edi) /* correct number of entries */
266: 1:
267:
268: movl 16(%esp),%eax
269: testl %eax,%eax
270: jz 1f
1.35 ! yamt 271: addl $KERNBASE,%eax
1.1 fvdl 272: 1: movl %eax,RELOC(esym)
273:
274: movl RELOC(biosextmem),%eax
275: testl %eax,%eax
276: jnz 1f
277: movl 20(%esp),%eax
278: movl %eax,RELOC(biosextmem)
279: 1:
280: movl RELOC(biosbasemem),%eax
281: testl %eax,%eax
282: jnz 1f
283: movl 24(%esp),%eax
284: movl %eax,RELOC(biosbasemem)
285: 1:
286:
287: /* First, reset the PSL. */
288: pushl $PSL_MBO
289: popfl
290:
291: /* Clear segment registers; always null in proc0. */
292: xorl %eax,%eax
293: movw %ax,%fs
294: movw %ax,%gs
295: decl %eax
296: movl %eax,RELOC(cpu_info_primary)+CPU_INFO_LEVEL
297:
298: /* Find out our CPU type. */
299:
300: try386: /* Try to toggle alignment check flag; does not exist on 386. */
301: pushfl
302: popl %eax
303: movl %eax,%ecx
304: orl $PSL_AC,%eax
305: pushl %eax
306: popfl
307: pushfl
308: popl %eax
309: xorl %ecx,%eax
310: andl $PSL_AC,%eax
311: pushl %ecx
312: popfl
313:
314: testl %eax,%eax
315: jnz try486
316:
317: /*
318: * Try the test of a NexGen CPU -- ZF will not change on a DIV
319: * instruction on a NexGen, it will on an i386. Documented in
320: * Nx586 Processor Recognition Application Note, NexGen, Inc.
321: */
322: movl $0x5555,%eax
323: xorl %edx,%edx
324: movl $2,%ecx
325: divl %ecx
326: jnz is386
327:
328: isnx586:
329: /*
330: * Don't try cpuid, as Nx586s reportedly don't support the
331: * PSL_ID bit.
332: */
333: movl $CPU_NX586,RELOC(cpu)
334: jmp 2f
335:
336: is386:
337: movl $CPU_386,RELOC(cpu)
338: jmp 2f
339:
340: try486: /* Try to toggle identification flag; does not exist on early 486s. */
341: pushfl
342: popl %eax
343: movl %eax,%ecx
344: xorl $PSL_ID,%eax
345: pushl %eax
346: popfl
347: pushfl
348: popl %eax
349: xorl %ecx,%eax
350: andl $PSL_ID,%eax
351: pushl %ecx
352: popfl
353:
354: testl %eax,%eax
355: jnz try586
356: is486: movl $CPU_486,RELOC(cpu)
357: /*
358: * Check Cyrix CPU
359: * Cyrix CPUs do not change the undefined flags following
360: * execution of the divide instruction which divides 5 by 2.
361: *
362: * Note: CPUID is enabled on M2, so it passes another way.
363: */
364: pushfl
365: movl $0x5555, %eax
366: xorl %edx, %edx
367: movl $2, %ecx
368: clc
369: divl %ecx
370: jnc trycyrix486
371: popfl
372: jmp 2f
373: trycyrix486:
374: movl $CPU_6x86,RELOC(cpu) # set CPU type
375: /*
376: * Check for Cyrix 486 CPU by seeing if the flags change during a
377: * divide. This is documented in the Cx486SLC/e SMM Programmer's
378: * Guide.
379: */
380: xorl %edx,%edx
381: cmpl %edx,%edx # set flags to known state
382: pushfl
383: popl %ecx # store flags in ecx
384: movl $-1,%eax
385: movl $4,%ebx
386: divl %ebx # do a long division
387: pushfl
388: popl %eax
389: xorl %ecx,%eax # are the flags different?
390: testl $0x8d5,%eax # only check C|PF|AF|Z|N|V
391: jne 2f # yes; must be Cyrix 6x86 CPU
392: movl $CPU_486DLC,RELOC(cpu) # set CPU type
393:
394: #ifndef CYRIX_CACHE_WORKS
395: /* Disable caching of the ISA hole only. */
396: invd
397: movb $CCR0,%al # Configuration Register index (CCR0)
398: outb %al,$0x22
399: inb $0x23,%al
400: orb $(CCR0_NC1|CCR0_BARB),%al
401: movb %al,%ah
402: movb $CCR0,%al
403: outb %al,$0x22
404: movb %ah,%al
405: outb %al,$0x23
406: invd
407: #else /* CYRIX_CACHE_WORKS */
408: /* Set cache parameters */
409: invd # Start with guaranteed clean cache
410: movb $CCR0,%al # Configuration Register index (CCR0)
411: outb %al,$0x22
412: inb $0x23,%al
413: andb $~CCR0_NC0,%al
414: #ifndef CYRIX_CACHE_REALLY_WORKS
415: orb $(CCR0_NC1|CCR0_BARB),%al
416: #else
417: orb $CCR0_NC1,%al
418: #endif
419: movb %al,%ah
420: movb $CCR0,%al
421: outb %al,$0x22
422: movb %ah,%al
423: outb %al,$0x23
424: /* clear non-cacheable region 1 */
425: movb $(NCR1+2),%al
426: outb %al,$0x22
427: movb $NCR_SIZE_0K,%al
428: outb %al,$0x23
429: /* clear non-cacheable region 2 */
430: movb $(NCR2+2),%al
431: outb %al,$0x22
432: movb $NCR_SIZE_0K,%al
433: outb %al,$0x23
434: /* clear non-cacheable region 3 */
435: movb $(NCR3+2),%al
436: outb %al,$0x22
437: movb $NCR_SIZE_0K,%al
438: outb %al,$0x23
439: /* clear non-cacheable region 4 */
440: movb $(NCR4+2),%al
441: outb %al,$0x22
442: movb $NCR_SIZE_0K,%al
443: outb %al,$0x23
444: /* enable caching in CR0 */
445: movl %cr0,%eax
446: andl $~(CR0_CD|CR0_NW),%eax
447: movl %eax,%cr0
448: invd
449: #endif /* CYRIX_CACHE_WORKS */
450:
451: jmp 2f
452:
453: try586: /* Use the `cpuid' instruction. */
454: xorl %eax,%eax
455: cpuid
456: movl %eax,RELOC(cpu_info_primary)+CPU_INFO_LEVEL
457:
458: 2:
459: /*
460: * Finished with old stack; load new %esp now instead of later so we
461: * can trace this code without having to worry about the trace trap
462: * clobbering the memory test or the zeroing of the bss+bootstrap page
463: * tables.
464: *
465: * The boot program should check:
466: * text+data <= &stack_variable - more_space_for_stack
467: * text+data+bss+pad+space_for_page_tables <= end_of_memory
468: * Oops, the gdt is in the carcass of the boot program so clearing
469: * the rest of memory is still not possible.
470: */
471: movl $_RELOC(tmpstk),%esp # bootstrap stack end location
472:
473: /*
474: * Virtual address space of kernel:
475: *
1.30 junyoung 476: * text | data | bss | [syms] | page dir | proc0 kstack
1.1 fvdl 477: * 0 1 2 3
478: */
1.7 thorpej 479: #define PROC0PDIR ((0) * PAGE_SIZE)
480: #define PROC0STACK ((1) * PAGE_SIZE)
481: #define SYSMAP ((1+UPAGES) * PAGE_SIZE)
482: #define TABLESIZE ((1+UPAGES) * PAGE_SIZE) /* + nkpde * PAGE_SIZE */
1.1 fvdl 483:
484: /* Find end of kernel image. */
485: movl $RELOC(end),%edi
1.8 fvdl 486: #if (NKSYMS || defined(DDB) || defined(LKM)) && !defined(SYMTAB_SPACE)
1.1 fvdl 487: /* Save the symbols (if loaded). */
488: movl RELOC(esym),%eax
489: testl %eax,%eax
490: jz 1f
1.35 ! yamt 491: subl $KERNBASE,%eax
1.1 fvdl 492: movl %eax,%edi
493: 1:
494: #endif
495:
496: /* Calculate where to start the bootstrap tables. */
497: movl %edi,%esi # edi = esym ? esym : end
498: addl $PGOFSET,%esi # page align up
499: andl $~PGOFSET,%esi
500:
501: /*
502: * Calculate the size of the kernel page table directory, and
1.29 mycroft 503: * how many entries it will have. Adjust nkpde to the actual
504: * kernel size automatically. Account for the bootstrap tables,
505: * round up, and add an extra 4MB.
1.1 fvdl 506: */
1.29 mycroft 507: leal TABLESIZE+NBPD+PDOFSET(%edi),%eax
508: shrl $PDSHIFT,%eax
1.1 fvdl 509: movl RELOC(nkpde),%ecx # get nkpde
1.29 mycroft 510: cmpl %ecx,%eax
511: jb 1f
512: movl %eax,%ecx
513: 1: cmpl $NKPTP_MIN,%ecx # larger than min?
1.1 fvdl 514: jge 1f
515: movl $NKPTP_MIN,%ecx # set at min
516: jmp 2f
517: 1: cmpl $NKPTP_MAX,%ecx # larger than max?
518: jle 2f
519: movl $NKPTP_MAX,%ecx
1.29 mycroft 520: 2: movl %ecx,RELOC(nkpde)
1.1 fvdl 521:
522: /* Clear memory for bootstrap tables. */
523: shll $PGSHIFT,%ecx
524: addl $TABLESIZE,%ecx
525: addl %esi,%ecx # end of tables
526: subl %edi,%ecx # size of tables
527: shrl $2,%ecx
528: xorl %eax,%eax
529: cld
530: rep
531: stosl
532:
533: /*
534: * fillkpt
535: * eax = pte (page frame | control | status)
536: * ebx = page table address
537: * ecx = number of pages to map
538: */
539: #define fillkpt \
540: 1: movl %eax,(%ebx) ; \
1.7 thorpej 541: addl $PAGE_SIZE,%eax ; /* increment physical address */ \
1.1 fvdl 542: addl $4,%ebx ; /* next pte */ \
543: loop 1b ;
544:
545: /*
546: * Build initial page tables.
547: */
548: /* Calculate end of text segment, rounded to a page. */
549: leal (RELOC(etext)+PGOFSET),%edx
550: andl $~PGOFSET,%edx
1.30 junyoung 551:
1.1 fvdl 552: /* Skip over the first 1MB. */
553: movl $_RELOC(KERNTEXTOFF),%eax
554: movl %eax,%ecx
555: shrl $PGSHIFT,%ecx
556: leal (SYSMAP)(%esi,%ecx,4),%ebx
557:
558: /* Map the kernel text read-only. */
559: movl %edx,%ecx
560: subl %eax,%ecx
561: shrl $PGSHIFT,%ecx
562: orl $(PG_V|PG_KR),%eax
563: fillkpt
564:
565: /* Map the data, BSS, and bootstrap tables read-write. */
566: leal (PG_V|PG_KW)(%edx),%eax
567: movl RELOC(nkpde),%ecx
568: shll $PGSHIFT,%ecx
569: addl $TABLESIZE,%ecx
570: addl %esi,%ecx # end of tables
571: subl %edx,%ecx # subtract end of text
572: shrl $PGSHIFT,%ecx
573: fillkpt
574:
575: /* Map ISA I/O memory. */
576: movl $(IOM_BEGIN|PG_V|PG_KW/*|PG_N*/),%eax # having these bits set
577: movl $(IOM_SIZE>>PGSHIFT),%ecx # for this many pte s,
578: fillkpt
579:
580: /*
581: * Construct a page table directory.
582: */
583: /* Install PDEs for temporary double map of kernel. */
584: movl RELOC(nkpde),%ecx # for this many pde s,
585: leal (PROC0PDIR+0*4)(%esi),%ebx # which is where temp maps!
586: leal (SYSMAP+PG_V|PG_KW)(%esi),%eax # pte for KPT in proc 0,
587: fillkpt
588:
589: /* Map kernel PDEs. */
590: movl RELOC(nkpde),%ecx # for this many pde s,
591: leal (PROC0PDIR+PDSLOT_KERN*4)(%esi),%ebx # kernel pde offset
592: leal (SYSMAP+PG_V|PG_KW)(%esi),%eax # pte for KPT in proc 0,
593: fillkpt
594:
595: /* Install a PDE recursively mapping page directory as a page table! */
596: leal (PROC0PDIR+PG_V|PG_KW)(%esi),%eax # pte for ptd
597: movl %eax,(PROC0PDIR+PDSLOT_PTE*4)(%esi) # recursive PD slot
598:
1.31 junyoung 599: /* Save phys. addr of PDP, for libkvm. */
600: movl %esi,RELOC(PDPpaddr)
1.1 fvdl 601:
602: /* Load base of page directory and enable mapping. */
603: movl %esi,%eax # phys address of ptd in proc 0
604: movl %eax,%cr3 # load ptd addr into mmu
605: movl %cr0,%eax # get control word
606: # enable paging & NPX emulation
607: orl $(CR0_PE|CR0_PG|CR0_NE|CR0_TS|CR0_EM|CR0_MP),%eax
608: movl %eax,%cr0 # and let's page NOW!
609:
610: pushl $begin # jump to high mem
611: ret
612:
613: begin:
1.35 ! yamt 614: /* Now running relocated at KERNBASE. Remove double mapping. */
1.1 fvdl 615: movl _C_LABEL(nkpde),%ecx # for this many pde s,
616: leal (PROC0PDIR+0*4)(%esi),%ebx # which is where temp maps!
1.35 ! yamt 617: addl $(KERNBASE), %ebx # now use relocated address
1.1 fvdl 618: 1: movl $0,(%ebx)
619: addl $4,%ebx # next pde
620: loop 1b
621:
622: /* Relocate atdevbase. */
623: movl _C_LABEL(nkpde),%edx
624: shll $PGSHIFT,%edx
1.35 ! yamt 625: addl $(TABLESIZE+KERNBASE),%edx
1.1 fvdl 626: addl %esi,%edx
627: movl %edx,_C_LABEL(atdevbase)
628:
629: /* Set up bootstrap stack. */
1.35 ! yamt 630: leal (PROC0STACK+KERNBASE)(%esi),%eax
1.1 fvdl 631: movl %eax,_C_LABEL(proc0paddr)
632: leal (USPACE-FRAMESIZE)(%eax),%esp
633: movl %esi,PCB_CR3(%eax) # pcb->pcb_cr3
634: xorl %ebp,%ebp # mark end of frames
635:
636: subl $NGDT*8, %esp # space for temporary gdt
637: pushl %esp
638: call _C_LABEL(initgdt)
639: addl $4,%esp
1.30 junyoung 640:
1.1 fvdl 641: movl _C_LABEL(nkpde),%eax
642: shll $PGSHIFT,%eax
643: addl $TABLESIZE,%eax
644: addl %esi,%eax # skip past stack and page tables
645:
646: pushl %eax
647: call _C_LABEL(init386) # wire 386 chip for unix operation
648: addl $4+NGDT*8,%esp # pop temporary gdt
649:
650: #ifdef SAFARI_FIFO_HACK
651: movb $5,%al
652: movw $0x37b,%dx
653: outb %al,%dx
654: movw $0x37f,%dx
655: inb %dx,%al
656: movb %al,%cl
657:
658: orb $1,%cl
659:
660: movb $5,%al
661: movw $0x37b,%dx
662: outb %al,%dx
663: movw $0x37f,%dx
664: movb %cl,%al
665: outb %al,%dx
666: #endif /* SAFARI_FIFO_HACK */
667:
668: call _C_LABEL(main)
669:
670: /*
671: * void proc_trampoline(void);
672: * This is a trampoline function pushed onto the stack of a newly created
673: * process in order to do some additional setup. The trampoline is entered by
674: * cpu_switch()ing to the process, so we abuse the callee-saved registers used
675: * by cpu_switch() to store the information about the stub to call.
676: * NOTE: This function does not have a normal calling sequence!
677: */
678: /* LINTSTUB: Func: void proc_trampoline(void) */
679: NENTRY(proc_trampoline)
680: #ifdef MULTIPROCESSOR
681: call _C_LABEL(proc_trampoline_mp)
682: #endif
683: movl $IPL_NONE,CPUVAR(ILEVEL)
684: pushl %ebx
685: call *%esi
686: addl $4,%esp
1.24 yamt 687: DO_DEFERRED_SWITCH(%eax)
1.1 fvdl 688: INTRFASTEXIT
689: /* NOTREACHED */
690:
691: /*****************************************************************************/
1.16 christos 692: #ifdef COMPAT_16
1.1 fvdl 693: /*
694: * Signal trampoline; copied to top of user stack.
695: */
696: /* LINTSTUB: Var: char sigcode[1], esigcode[1]; */
697: NENTRY(sigcode)
698: /*
699: * Handler has returned here as if we called it. The sigcontext
700: * is on the stack after the 3 args "we" pushed.
701: */
702: leal 12(%esp),%eax # get pointer to sigcontext
703: movl %eax,4(%esp) # put it in the argument slot
704: # fake return address already there
1.17 christos 705: movl $SYS_compat_16___sigreturn14,%eax
1.1 fvdl 706: int $0x80 # enter kernel with args on stack
707: movl $SYS_exit,%eax
708: int $0x80 # exit if sigreturn fails
709: .globl _C_LABEL(esigcode)
710: _C_LABEL(esigcode):
1.16 christos 711: #endif
1.1 fvdl 712:
713: /*****************************************************************************/
714:
715: /*
716: * The following is i386-specific nonsense.
717: */
718:
719: /*
720: * void lgdt(struct region_descriptor *rdp);
721: * Load a new GDT pointer (and do any necessary cleanup).
722: * XXX It's somewhat questionable whether reloading all the segment registers
723: * is necessary, since the actual descriptor data is not changed except by
724: * process creation and exit, both of which clean up via task switches. OTOH,
725: * this only happens at run time when the GDT is resized.
726: */
727: /* LINTSTUB: Func: void lgdt(struct region_descriptor *rdp) */
728: NENTRY(lgdt)
729: /* Reload the descriptor table. */
730: movl 4(%esp),%eax
731: lgdt (%eax)
732: /* Flush the prefetch queue. */
733: jmp 1f
734: nop
735: 1: /* Reload "stale" selectors. */
736: movl $GSEL(GDATA_SEL, SEL_KPL),%eax
737: movw %ax,%ds
738: movw %ax,%es
739: movw %ax,%gs
740: movw %ax,%ss
741: movl $GSEL(GCPU_SEL, SEL_KPL),%eax
742: movw %ax,%fs
743: /* Reload code selector by doing intersegment return. */
744: popl %eax
745: pushl $GSEL(GCODE_SEL, SEL_KPL)
746: pushl %eax
747: lret
748:
749: /*****************************************************************************/
750:
751: /*
752: * These functions are primarily used by DDB.
753: */
754:
755: /* LINTSTUB: Func: int setjmp (label_t *l) */
756: ENTRY(setjmp)
757: movl 4(%esp),%eax
758: movl %ebx,(%eax) # save ebx
759: movl %esp,4(%eax) # save esp
760: movl %ebp,8(%eax) # save ebp
761: movl %esi,12(%eax) # save esi
762: movl %edi,16(%eax) # save edi
763: movl (%esp),%edx # get rta
764: movl %edx,20(%eax) # save eip
765: xorl %eax,%eax # return (0);
766: ret
767:
768: /* LINTSTUB: Func: void longjmp (label_t *l) */
769: ENTRY(longjmp)
770: movl 4(%esp),%eax
771: movl (%eax),%ebx # restore ebx
772: movl 4(%eax),%esp # restore esp
773: movl 8(%eax),%ebp # restore ebp
774: movl 12(%eax),%esi # restore esi
775: movl 16(%eax),%edi # restore edi
776: movl 20(%eax),%edx # get rta
777: movl %edx,(%esp) # put in return frame
778: xorl %eax,%eax # return (1);
779: incl %eax
780: ret
781:
782: /*****************************************************************************/
783:
784: .globl _C_LABEL(sched_whichqs),_C_LABEL(sched_qs)
785: .globl _C_LABEL(uvmexp),_C_LABEL(panic)
786:
787: #ifdef DIAGNOSTIC
788: NENTRY(switch_error)
789: pushl $1f
790: call _C_LABEL(panic)
791: /* NOTREACHED */
792: 1: .asciz "cpu_switch"
793: #endif /* DIAGNOSTIC */
794:
795: /*
1.5 thorpej 796: * void cpu_switch(struct lwp *)
1.1 fvdl 797: * Find a runnable process and switch to it. Wait if necessary. If the new
798: * process is the same as the old one, we short-circuit the context save and
799: * restore.
1.30 junyoung 800: *
1.1 fvdl 801: * Note that the stack frame layout is known to "struct switchframe"
1.30 junyoung 802: * in <machine/frame.h> and to the code in cpu_fork() which initializes
1.5 thorpej 803: * it for a new lwp.
1.1 fvdl 804: */
805: ENTRY(cpu_switch)
806: pushl %ebx
807: pushl %esi
808: pushl %edi
809:
810: #ifdef DEBUG
811: cmpl $IPL_SCHED,CPUVAR(ILEVEL)
812: jae 1f
1.5 thorpej 813: pushl $2f
1.1 fvdl 814: call _C_LABEL(panic)
815: /* NOTREACHED */
1.5 thorpej 816: 2: .asciz "not splsched() in cpu_switch!"
1.30 junyoung 817: 1:
1.1 fvdl 818: #endif /* DEBUG */
1.30 junyoung 819:
1.5 thorpej 820: movl 16(%esp),%esi # current
1.1 fvdl 821:
822: /*
1.5 thorpej 823: * Clear curlwp so that we don't accumulate system time while idle.
824: * This also insures that schedcpu() will move the old lwp to
1.1 fvdl 825: * the correct queue if it happens to get called from the spllower()
826: * below and changes the priority. (See corresponding comment in
827: * userret()).
828: */
1.5 thorpej 829: movl $0,CPUVAR(CURLWP)
1.1 fvdl 830: /*
1.5 thorpej 831: * First phase: find new lwp.
1.1 fvdl 832: *
833: * Registers:
834: * %eax - queue head, scratch, then zero
835: * %ebx - queue number
836: * %ecx - cached value of whichqs
1.5 thorpej 837: * %edx - next lwp in queue
838: * %esi - old lwp
839: * %edi - new lwp
1.1 fvdl 840: */
841:
1.5 thorpej 842: /* Look for new lwp. */
1.1 fvdl 843: cli # splhigh doesn't do a cli
844: movl _C_LABEL(sched_whichqs),%ecx
845: bsfl %ecx,%ebx # find a full q
846: jnz switch_dequeue
847:
848: /*
849: * idling: save old context.
850: *
851: * Registers:
852: * %eax, %ecx - scratch
1.5 thorpej 853: * %esi - old lwp, then old pcb
1.1 fvdl 854: * %edi - idle pcb
855: */
856:
857: pushl %esi
1.24 yamt 858: call _C_LABEL(pmap_deactivate2) # pmap_deactivate(oldproc)
1.1 fvdl 859: addl $4,%esp
860:
1.5 thorpej 861: movl L_ADDR(%esi),%esi
1.1 fvdl 862:
863: /* Save stack pointers. */
864: movl %esp,PCB_ESP(%esi)
865: movl %ebp,PCB_EBP(%esi)
866:
867: /* Find idle PCB for this CPU */
868: #ifndef MULTIPROCESSOR
1.5 thorpej 869: movl $_C_LABEL(lwp0),%ebx
870: movl L_ADDR(%ebx),%edi
871: movl L_MD_TSS_SEL(%ebx),%edx
1.1 fvdl 872: #else
873: movl CPUVAR(IDLE_PCB),%edi
874: movl CPUVAR(IDLE_TSS_SEL),%edx
875: #endif
1.5 thorpej 876: movl $0,CPUVAR(CURLWP) /* In case we fault... */
1.1 fvdl 877:
878: /* Restore the idle context (avoid interrupts) */
879: cli
880:
881: /* Restore stack pointers. */
882: movl PCB_ESP(%edi),%esp
883: movl PCB_EBP(%edi),%ebp
884:
885: /* Switch TSS. Reset "task busy" flag before loading. */
1.26 yamt 886: movl %cr3,%eax
887: movl %eax,PCB_CR3(%edi)
1.1 fvdl 888: #ifdef MULTIPROCESSOR
889: movl CPUVAR(GDT),%eax
890: #else
891: movl _C_LABEL(gdt),%eax
892: #endif
893: andl $~0x0200,4-SEL_KPL(%eax,%edx,1)
894: ltr %dx
895:
896: /* We're always in the kernel, so we don't need the LDT. */
897:
898: /* Restore cr0 (including FPU state). */
899: movl PCB_CR0(%edi),%ecx
900: movl %ecx,%cr0
901:
902: /* Record new pcb. */
903: SET_CURPCB(%edi)
904:
905: xorl %esi,%esi
906: sti
1.30 junyoung 907: idle_unlock:
908: #if defined(MULTIPROCESSOR) || defined(LOCKDEBUG)
1.1 fvdl 909: call _C_LABEL(sched_unlock_idle)
910: #endif
911: /* Interrupts are okay again. */
1.2 fvdl 912: pushl $IPL_NONE # spl0()
1.1 fvdl 913: call _C_LABEL(Xspllower) # process pending interrupts
1.2 fvdl 914: addl $4,%esp
1.1 fvdl 915: jmp idle_start
1.30 junyoung 916: idle_zero:
1.1 fvdl 917: sti
918: call _C_LABEL(uvm_pageidlezero)
919: cli
920: cmpl $0,_C_LABEL(sched_whichqs)
921: jnz idle_exit
922: idle_loop:
923: /* Try to zero some pages. */
924: movl _C_LABEL(uvm)+UVM_PAGE_IDLE_ZERO,%ecx
925: testl %ecx,%ecx
926: jnz idle_zero
927: sti
928: hlt
929: NENTRY(mpidle)
1.30 junyoung 930: idle_start:
1.1 fvdl 931: cli
932: cmpl $0,_C_LABEL(sched_whichqs)
933: jz idle_loop
1.30 junyoung 934: idle_exit:
1.1 fvdl 935: movl $IPL_HIGH,CPUVAR(ILEVEL) # splhigh
1.14 fvdl 936: sti
1.30 junyoung 937: #if defined(MULTIPROCESSOR) || defined(LOCKDEBUG)
1.1 fvdl 938: call _C_LABEL(sched_lock_idle)
939: #endif
940: movl _C_LABEL(sched_whichqs),%ecx
941: bsfl %ecx,%ebx
942: jz idle_unlock
943:
1.30 junyoung 944: switch_dequeue:
945: /*
1.1 fvdl 946: * we're running at splhigh(), but it's otherwise okay to take
1.30 junyoung 947: * interrupts here.
1.1 fvdl 948: */
949: sti
950: leal _C_LABEL(sched_qs)(,%ebx,8),%eax # select q
951:
1.5 thorpej 952: movl L_FORW(%eax),%edi # unlink from front of process q
1.1 fvdl 953: #ifdef DIAGNOSTIC
954: cmpl %edi,%eax # linked to self (i.e. nothing queued)?
955: je _C_LABEL(switch_error) # not possible
956: #endif /* DIAGNOSTIC */
1.5 thorpej 957: movl L_FORW(%edi),%edx
958: movl %edx,L_FORW(%eax)
959: movl %eax,L_BACK(%edx)
1.1 fvdl 960:
961: cmpl %edx,%eax # q empty?
962: jne 3f
963:
964: btrl %ebx,%ecx # yes, clear to indicate empty
965: movl %ecx,_C_LABEL(sched_whichqs) # update q status
966:
967: 3: /* We just did it. */
968: xorl %eax,%eax
969: CLEAR_RESCHED(%eax)
970:
1.5 thorpej 971: switch_resume:
1.1 fvdl 972: #ifdef DIAGNOSTIC
1.5 thorpej 973: cmpl %eax,L_WCHAN(%edi) # Waiting for something?
1.1 fvdl 974: jne _C_LABEL(switch_error) # Yes; shouldn't be queued.
1.5 thorpej 975: cmpb $LSRUN,L_STAT(%edi) # In run state?
1.1 fvdl 976: jne _C_LABEL(switch_error) # No; shouldn't be queued.
977: #endif /* DIAGNOSTIC */
978:
1.5 thorpej 979: /* Isolate lwp. XXX Is this necessary? */
980: movl %eax,L_BACK(%edi)
1.1 fvdl 981:
1.5 thorpej 982: /* Record new lwp. */
983: movb $LSONPROC,L_STAT(%edi) # l->l_stat = LSONPROC
984: SET_CURLWP(%edi,%ecx)
1.1 fvdl 985:
1.5 thorpej 986: /* Skip context switch if same lwp. */
1.10 fvdl 987: xorl %ebx,%ebx
1.1 fvdl 988: cmpl %edi,%esi
989: je switch_return
990:
1.5 thorpej 991: /* If old lwp exited, don't bother. */
1.1 fvdl 992: testl %esi,%esi
993: jz switch_exited
994:
995: /*
996: * Second phase: save old context.
997: *
998: * Registers:
999: * %eax, %ecx - scratch
1.5 thorpej 1000: * %esi - old lwp, then old pcb
1001: * %edi - new lwp
1.1 fvdl 1002: */
1003:
1004: pushl %esi
1.24 yamt 1005: call _C_LABEL(pmap_deactivate2) # pmap_deactivate(oldproc)
1.1 fvdl 1006: addl $4,%esp
1007:
1.5 thorpej 1008: movl L_ADDR(%esi),%esi
1.1 fvdl 1009:
1010: /* Save stack pointers. */
1011: movl %esp,PCB_ESP(%esi)
1012: movl %ebp,PCB_EBP(%esi)
1013:
1014: switch_exited:
1015: /*
1016: * Third phase: restore saved context.
1017: *
1018: * Registers:
1019: * %eax, %ebx, %ecx, %edx - scratch
1020: * %esi - new pcb
1.5 thorpej 1021: * %edi - new lwp
1.1 fvdl 1022: */
1023:
1024: /* No interrupts while loading new state. */
1025: cli
1.5 thorpej 1026: movl L_ADDR(%edi),%esi
1.1 fvdl 1027:
1028: /* Restore stack pointers. */
1029: movl PCB_ESP(%esi),%esp
1030: movl PCB_EBP(%esi),%ebp
1031:
1032: #if 0
1033: /* Don't bother with the rest if switching to a system process. */
1.5 thorpej 1034: testl $P_SYSTEM,L_FLAG(%edi); XXX NJWLWP lwp's don't have P_SYSTEM!
1.1 fvdl 1035: jnz switch_restored
1036: #endif
1037:
1.26 yamt 1038: /* Switch TSS. Reset "task busy" flag before loading. */
1039: movl %cr3,%eax
1040: movl %eax,PCB_CR3(%esi) /* XXX should be done by pmap_activate? */
1.1 fvdl 1041: #ifdef MULTIPROCESSOR
1042: movl CPUVAR(GDT),%eax
1.30 junyoung 1043: #else
1.1 fvdl 1044: /* Load TSS info. */
1045: movl _C_LABEL(gdt),%eax
1046: #endif
1.5 thorpej 1047: movl L_MD_TSS_SEL(%edi),%edx
1.1 fvdl 1048:
1049: andl $~0x0200,4(%eax,%edx, 1)
1050: ltr %dx
1051:
1052: pushl %edi
1053: call _C_LABEL(pmap_activate) # pmap_activate(p)
1054: addl $4,%esp
1055:
1056: #if 0
1057: switch_restored:
1058: #endif
1059: /* Restore cr0 (including FPU state). */
1060: movl PCB_CR0(%esi),%ecx
1061: #ifdef MULTIPROCESSOR
1.30 junyoung 1062: /*
1.22 wiz 1063: * If our floating point registers are on a different CPU,
1.1 fvdl 1064: * clear CR0_TS so we'll trap rather than reuse bogus state.
1065: */
1066: movl PCB_FPCPU(%esi),%ebx
1067: cmpl CPUVAR(SELF),%ebx
1068: jz 1f
1069: orl $CR0_TS,%ecx
1.30 junyoung 1070: 1:
1071: #endif
1.1 fvdl 1072: movl %ecx,%cr0
1073:
1074: /* Record new pcb. */
1075: SET_CURPCB(%esi)
1076:
1077: /* Interrupts are okay again. */
1078: sti
1079:
1080: /*
1081: * Check for restartable atomic sequences (RAS)
1082: */
1.5 thorpej 1083: movl CPUVAR(CURLWP),%edi
1084: movl L_PROC(%edi),%esi
1.20 dsl 1085: cmpl $0,P_RASLIST(%esi)
1086: jne 2f
1.1 fvdl 1087: 1:
1.10 fvdl 1088: movl $1,%ebx
1.1 fvdl 1089:
1090: switch_return:
1.30 junyoung 1091: #if defined(MULTIPROCESSOR) || defined(LOCKDEBUG)
1.1 fvdl 1092: call _C_LABEL(sched_unlock_idle)
1093: #endif
1.28 yamt 1094: cmpl $0,CPUVAR(IPENDING)
1095: jz 3f
1.2 fvdl 1096: pushl $IPL_NONE # spl0()
1.1 fvdl 1097: call _C_LABEL(Xspllower) # process pending interrupts
1.2 fvdl 1098: addl $4,%esp
1.28 yamt 1099: 3:
1.1 fvdl 1100: movl $IPL_HIGH,CPUVAR(ILEVEL) # splhigh()
1.9 fvdl 1101:
1102: movl %ebx,%eax
1.30 junyoung 1103:
1.1 fvdl 1104: popl %edi
1105: popl %esi
1106: popl %ebx
1107: ret
1.20 dsl 1108:
1109: 2: # check RAS list
1110: movl L_MD_REGS(%edi),%ebx
1111: movl TF_EIP(%ebx),%eax
1112: pushl %eax
1113: pushl %esi
1114: call _C_LABEL(ras_lookup)
1115: addl $8,%esp
1116: cmpl $-1,%eax
1117: je 1b
1118: movl %eax,TF_EIP(%ebx)
1119: jmp 1b
1.1 fvdl 1120:
1121: /*
1.5 thorpej 1122: * void cpu_switchto(struct lwp *current, struct lwp *next)
1123: * Switch to the specified next LWP.
1124: */
1125: ENTRY(cpu_switchto)
1126: pushl %ebx
1127: pushl %esi
1128: pushl %edi
1129:
1130: #ifdef DEBUG
1131: cmpl $IPL_SCHED,CPUVAR(ILEVEL)
1132: jae 1f
1133: pushl $2f
1134: call _C_LABEL(panic)
1135: /* NOTREACHED */
1136: 2: .asciz "not splsched() in cpu_switchto!"
1137: 1:
1138: #endif /* DEBUG */
1139:
1140: movl 16(%esp),%esi # current
1141: movl 20(%esp),%edi # next
1142:
1143: /*
1144: * Clear curlwp so that we don't accumulate system time while idle.
1145: * This also insures that schedcpu() will move the old process to
1146: * the correct queue if it happens to get called from the spllower()
1147: * below and changes the priority. (See corresponding comment in
1148: * usrret()).
1149: *
1150: * XXX Is this necessary? We know we won't go idle.
1151: */
1152: movl $0,CPUVAR(CURLWP)
1153:
1154: /*
1155: * We're running at splhigh(), but it's otherwise okay to take
1156: * interrupts here.
1157: */
1158: sti
1159:
1160: /* Jump into the middle of cpu_switch */
1161: xorl %eax,%eax
1162: jmp switch_resume
1163:
1164: /*
1.21 jdolecek 1165: * void cpu_exit(struct lwp *l)
1.30 junyoung 1166: * Switch to the appropriate idle context (lwp0's if uniprocessor; the CPU's
1167: * if multiprocessor) and deallocate the address space and kernel stack for p.
1.1 fvdl 1168: * Then jump into cpu_switch(), as if we were in the idle proc all along.
1169: */
1170: #ifndef MULTIPROCESSOR
1.5 thorpej 1171: .globl _C_LABEL(lwp0)
1.1 fvdl 1172: #endif
1.21 jdolecek 1173: /* LINTSTUB: Func: void cpu_exit(struct lwp *l) */
1174: ENTRY(cpu_exit)
1.1 fvdl 1175: movl 4(%esp),%edi # old process
1176: #ifndef MULTIPROCESSOR
1.5 thorpej 1177: movl $_C_LABEL(lwp0),%ebx
1178: movl L_ADDR(%ebx),%esi
1179: movl L_MD_TSS_SEL(%ebx),%edx
1.1 fvdl 1180: #else
1181: movl CPUVAR(IDLE_PCB),%esi
1182: movl CPUVAR(IDLE_TSS_SEL),%edx
1183: #endif
1184: /* In case we fault... */
1.5 thorpej 1185: movl $0,CPUVAR(CURLWP)
1.1 fvdl 1186:
1187: /* Restore the idle context. */
1188: cli
1189:
1190: /* Restore stack pointers. */
1191: movl PCB_ESP(%esi),%esp
1192: movl PCB_EBP(%esi),%ebp
1193:
1.26 yamt 1194: /* Switch TSS. Reset "task busy" flag before loading. */
1195: movl %cr3,%eax
1196: movl %eax,PCB_CR3(%esi)
1.1 fvdl 1197: #ifdef MULTIPROCESSOR
1198: movl CPUVAR(GDT),%eax
1.30 junyoung 1199: #else
1.1 fvdl 1200: /* Load TSS info. */
1201: movl _C_LABEL(gdt),%eax
1202: #endif
1203:
1204: andl $~0x0200,4-SEL_KPL(%eax,%edx,1)
1205: ltr %dx
1206:
1207: /* We're always in the kernel, so we don't need the LDT. */
1208:
1209: /* Restore cr0 (including FPU state). */
1210: movl PCB_CR0(%esi),%ecx
1211: movl %ecx,%cr0
1212:
1213: /* Record new pcb. */
1214: SET_CURPCB(%esi)
1215:
1216: /* Interrupts are okay again. */
1217: sti
1218:
1219: /*
1.21 jdolecek 1220: * Schedule the dead LWP's stack to be freed.
1.1 fvdl 1221: */
1.21 jdolecek 1222: pushl %edi
1223: call _C_LABEL(lwp_exit2)
1.1 fvdl 1224: addl $4,%esp
1225:
1226: /* Jump into cpu_switch() with the right state. */
1227: xorl %esi,%esi
1.5 thorpej 1228: movl %esi,CPUVAR(CURLWP)
1.1 fvdl 1229: jmp idle_start
1230:
1231: /*
1232: * void savectx(struct pcb *pcb);
1233: * Update pcb, saving current processor state.
1234: */
1235: /* LINTSTUB: Func: void savectx(struct pcb *pcb) */
1236: ENTRY(savectx)
1237: movl 4(%esp),%edx # edx = p->p_addr
1.30 junyoung 1238:
1.1 fvdl 1239: /* Save stack pointers. */
1240: movl %esp,PCB_ESP(%edx)
1241: movl %ebp,PCB_EBP(%edx)
1242:
1243: ret
1244:
1245: /*
1246: * Old call gate entry for syscall
1247: */
1248: /* LINTSTUB: Var: char Xosyscall[1]; */
1249: IDTVEC(osyscall)
1250: /* Set eflags in trap frame. */
1251: pushfl
1252: popl 8(%esp)
1253: pushl $7 # size of instruction for restart
1254: jmp syscall1
1255:
1256: /*
1257: * Trap gate entry for syscall
1258: */
1259: /* LINTSTUB: Var: char Xsyscall[1]; */
1260: IDTVEC(syscall)
1261: pushl $2 # size of instruction for restart
1262: syscall1:
1263: pushl $T_ASTFLT # trap # for doing ASTs
1264: INTRENTRY
1265:
1266: #ifdef DIAGNOSTIC
1.24 yamt 1267: cmpl $0, CPUVAR(WANT_PMAPLOAD)
1268: jz 1f
1269: pushl $6f
1270: call _C_LABEL(printf)
1271: addl $4, %esp
1272: 1:
1.1 fvdl 1273: movl CPUVAR(ILEVEL),%ebx
1274: testl %ebx,%ebx
1275: jz 1f
1276: pushl $5f
1277: call _C_LABEL(printf)
1278: addl $4,%esp
1279: #ifdef DDB
1280: int $3
1281: #endif
1.30 junyoung 1282: 1:
1.1 fvdl 1283: #endif /* DIAGNOSTIC */
1.5 thorpej 1284: movl CPUVAR(CURLWP),%edx
1285: movl %esp,L_MD_REGS(%edx) # save pointer to frame
1286: movl L_PROC(%edx),%edx
1.15 fvdl 1287: pushl %esp
1.1 fvdl 1288: call *P_MD_SYSCALL(%edx) # get pointer to syscall() function
1.15 fvdl 1289: addl $4,%esp
1.27 yamt 1290: .Lsyscall_checkast:
1.24 yamt 1291: /* Check for ASTs on exit to user mode. */
1.1 fvdl 1292: cli
1.5 thorpej 1293: CHECK_ASTPENDING(%eax)
1.1 fvdl 1294: je 1f
1295: /* Always returning to user mode here. */
1.5 thorpej 1296: CLEAR_ASTPENDING(%eax)
1.1 fvdl 1297: sti
1298: /* Pushed T_ASTFLT into tf_trapno on entry. */
1.15 fvdl 1299: pushl %esp
1.1 fvdl 1300: call _C_LABEL(trap)
1.15 fvdl 1301: addl $4,%esp
1.27 yamt 1302: jmp .Lsyscall_checkast /* re-check ASTs */
1.24 yamt 1303: 1: CHECK_DEFERRED_SWITCH(%eax)
1304: jnz 9f
1.1 fvdl 1305: #ifndef DIAGNOSTIC
1.24 yamt 1306: INTRFASTEXIT
1.1 fvdl 1307: #else /* DIAGNOSTIC */
1.24 yamt 1308: cmpl $IPL_NONE,CPUVAR(ILEVEL)
1.1 fvdl 1309: jne 3f
1310: INTRFASTEXIT
1311: 3: sti
1312: pushl $4f
1313: call _C_LABEL(printf)
1314: addl $4,%esp
1315: #ifdef DDB
1316: int $3
1317: #endif /* DDB */
1318: movl $IPL_NONE,CPUVAR(ILEVEL)
1319: jmp 2b
1320: 4: .asciz "WARNING: SPL NOT LOWERED ON SYSCALL EXIT\n"
1.30 junyoung 1321: 5: .asciz "WARNING: SPL NOT ZERO ON SYSCALL ENTRY\n"
1322: 6: .asciz "WARNING: WANT PMAPLOAD ON SYSCALL ENTRY\n"
1.1 fvdl 1323: #endif /* DIAGNOSTIC */
1.24 yamt 1324: 9: sti
1325: call _C_LABEL(pmap_load)
1.27 yamt 1326: jmp .Lsyscall_checkast /* re-check ASTs */
1.1 fvdl 1327:
1328: #if NNPX > 0
1329: /*
1330: * Special interrupt handlers. Someday intr0-intr15 will be used to count
1331: * interrupts. We'll still need a special exception 16 handler. The busy
1332: * latch stuff in probintr() can be moved to npxprobe().
1333: */
1334:
1335: /* LINTSTUB: Func: void probeintr(void) */
1336: NENTRY(probeintr)
1337: ss
1338: incl _C_LABEL(npx_intrs_while_probing)
1339: pushl %eax
1340: movb $0x20,%al # EOI (asm in strings loses cpp features)
1341: outb %al,$0xa0 # IO_ICU2
1342: outb %al,$0x20 # IO_ICU1
1343: movb $0,%al
1344: outb %al,$0xf0 # clear BUSY# latch
1345: popl %eax
1346: iret
1347:
1348: /* LINTSTUB: Func: void probetrap(void) */
1349: NENTRY(probetrap)
1350: ss
1351: incl _C_LABEL(npx_traps_while_probing)
1352: fnclex
1353: iret
1354:
1355: /* LINTSTUB: Func: int npx586bug1(int a, int b) */
1356: NENTRY(npx586bug1)
1357: fildl 4(%esp) # x
1358: fildl 8(%esp) # y
1359: fld %st(1)
1360: fdiv %st(1),%st # x/y
1361: fmulp %st,%st(1) # (x/y)*y
1362: fsubrp %st,%st(1) # x-(x/y)*y
1363: pushl $0
1364: fistpl (%esp)
1365: popl %eax
1366: ret
1367: #endif /* NNPX > 0 */
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