Annotation of src/sys/arch/i386/i386/locore.S, Revision 1.42
1.42 ! christos 1: /* $NetBSD: locore.S,v 1.41 2006/07/01 09:21:28 jmmv Exp $ */
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 "lapic.h"
87: #include "ioapic.h"
1.8 fvdl 88: #include "ksyms.h"
1.1 fvdl 89:
90: #include <sys/errno.h>
91: #include <sys/syscall.h>
92:
93: #include <machine/cputypes.h>
94: #include <machine/segments.h>
95: #include <machine/specialreg.h>
96: #include <machine/trap.h>
97:
98: #if NLAPIC > 0
99: #include <machine/i82489reg.h>
100: #endif
101:
1.37 jmmv 102: #include <machine/multiboot.h>
103:
1.1 fvdl 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)
1.38 jmmv 159: .globl _C_LABEL(esym)
160: .globl _C_LABEL(atdevbase)
1.40 yamt 161: .globl _C_LABEL(proc0uarea),_C_LABEL(PDPpaddr)
1.1 fvdl 162: .globl _C_LABEL(gdt)
163: #ifdef I586_CPU
164: .globl _C_LABEL(idt)
165: #endif
1.30 junyoung 166: .globl _C_LABEL(lapic_tpr)
167:
1.1 fvdl 168: #if NLAPIC > 0
169: #ifdef __ELF__
1.7 thorpej 170: .align PAGE_SIZE
1.1 fvdl 171: #else
172: .align 12
173: #endif
174: .globl _C_LABEL(local_apic), _C_LABEL(lapic_id)
175: _C_LABEL(local_apic):
176: .space LAPIC_ID
1.30 junyoung 177: _C_LABEL(lapic_id):
1.1 fvdl 178: .long 0x00000000
179: .space LAPIC_TPRI-(LAPIC_ID+4)
1.30 junyoung 180: _C_LABEL(lapic_tpr):
1.1 fvdl 181: .space LAPIC_PPRI-LAPIC_TPRI
1.30 junyoung 182: _C_LABEL(lapic_ppr):
1.1 fvdl 183: .space LAPIC_ISR-LAPIC_PPRI
184: _C_LABEL(lapic_isr):
1.7 thorpej 185: .space PAGE_SIZE-LAPIC_ISR
1.1 fvdl 186: #else
1.30 junyoung 187: _C_LABEL(lapic_tpr):
1.1 fvdl 188: .long 0
189: #endif
1.30 junyoung 190:
1.1 fvdl 191:
192: _C_LABEL(cpu): .long 0 # are we 386, 386sx, or 486,
193: # or Pentium, or..
194: _C_LABEL(atdevbase): .long 0 # location of start of iomem in virtual
1.40 yamt 195: _C_LABEL(proc0uarea): .long 0
1.31 junyoung 196: _C_LABEL(PDPpaddr): .long 0 # paddr of PDP, for libkvm
1.30 junyoung 197:
1.1 fvdl 198: .space 512
199: tmpstk:
200:
201:
1.35 yamt 202: #define _RELOC(x) ((x) - KERNBASE)
1.1 fvdl 203: #define RELOC(x) _RELOC(_C_LABEL(x))
204:
205: .text
206: .globl _C_LABEL(kernel_text)
207: .set _C_LABEL(kernel_text),KERNTEXTOFF
208:
209: .globl start
210: start: movw $0x1234,0x472 # warm boot
211:
1.37 jmmv 212: #if defined(MULTIBOOT)
213: jmp 1f
214:
215: .align 4
216: .globl Multiboot_Header
217: _C_LABEL(Multiboot_Header):
218: #define MULTIBOOT_HEADER_FLAGS (MULTIBOOT_HEADER_WANT_MEMORY | \
219: MULTIBOOT_HEADER_HAS_ADDR)
220: .long MULTIBOOT_HEADER_MAGIC
221: .long MULTIBOOT_HEADER_FLAGS
222: .long -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS)
223: .long RELOC(Multiboot_Header)
224: .long RELOC(start)
225: .long RELOC(_edata)
226: .long RELOC(_end) + MULTIBOOT_SYMTAB_SPACE
227: .long RELOC(start)
228:
229: 1:
230: /* Check if we are being executed by a Multiboot-compliant boot
231: * loader. */
232: cmpl $MULTIBOOT_INFO_MAGIC,%eax
233: jne 1f
234:
235: /* Indeed, a multiboot-compliat boot loader executed us. We copy
236: * the received Multiboot information structure into kernel's data
237: * space to process it later -- after we are relocated. It will
238: * be safer to run complex C code than doing it at this point. */
239: pushl %ebx # Address of Multiboot information
240: call _C_LABEL(multiboot_pre_reloc)
241: addl $4,%esp
1.38 jmmv 242: jmp 2f
1.37 jmmv 243: #endif
244:
245: 1:
1.1 fvdl 246: /*
1.38 jmmv 247: * At this point, we know that a NetBSD-specific boot loader
248: * booted this kernel. The stack carries the following parameters:
1.41 jmmv 249: * (boothowto, [bootdev], bootinfo, esym, biosextmem, biosbasemem),
1.38 jmmv 250: * 4 bytes each.
1.1 fvdl 251: */
1.38 jmmv 252: addl $4,%esp # Discard return address to boot loader
253: call _C_LABEL(native_loader)
254: addl $24,%esp
1.1 fvdl 255:
256: 2:
257: /* First, reset the PSL. */
258: pushl $PSL_MBO
259: popfl
260:
261: /* Clear segment registers; always null in proc0. */
262: xorl %eax,%eax
263: movw %ax,%fs
264: movw %ax,%gs
265: decl %eax
266: movl %eax,RELOC(cpu_info_primary)+CPU_INFO_LEVEL
267:
268: /* Find out our CPU type. */
269:
270: try386: /* Try to toggle alignment check flag; does not exist on 386. */
271: pushfl
272: popl %eax
273: movl %eax,%ecx
274: orl $PSL_AC,%eax
275: pushl %eax
276: popfl
277: pushfl
278: popl %eax
279: xorl %ecx,%eax
280: andl $PSL_AC,%eax
281: pushl %ecx
282: popfl
283:
284: testl %eax,%eax
285: jnz try486
286:
287: /*
288: * Try the test of a NexGen CPU -- ZF will not change on a DIV
289: * instruction on a NexGen, it will on an i386. Documented in
290: * Nx586 Processor Recognition Application Note, NexGen, Inc.
291: */
292: movl $0x5555,%eax
293: xorl %edx,%edx
294: movl $2,%ecx
295: divl %ecx
296: jnz is386
297:
298: isnx586:
299: /*
300: * Don't try cpuid, as Nx586s reportedly don't support the
301: * PSL_ID bit.
302: */
303: movl $CPU_NX586,RELOC(cpu)
304: jmp 2f
305:
306: is386:
307: movl $CPU_386,RELOC(cpu)
308: jmp 2f
309:
310: try486: /* Try to toggle identification flag; does not exist on early 486s. */
311: pushfl
312: popl %eax
313: movl %eax,%ecx
314: xorl $PSL_ID,%eax
315: pushl %eax
316: popfl
317: pushfl
318: popl %eax
319: xorl %ecx,%eax
320: andl $PSL_ID,%eax
321: pushl %ecx
322: popfl
323:
324: testl %eax,%eax
325: jnz try586
326: is486: movl $CPU_486,RELOC(cpu)
327: /*
328: * Check Cyrix CPU
329: * Cyrix CPUs do not change the undefined flags following
330: * execution of the divide instruction which divides 5 by 2.
331: *
332: * Note: CPUID is enabled on M2, so it passes another way.
333: */
334: pushfl
335: movl $0x5555, %eax
336: xorl %edx, %edx
337: movl $2, %ecx
338: clc
339: divl %ecx
340: jnc trycyrix486
341: popfl
342: jmp 2f
343: trycyrix486:
344: movl $CPU_6x86,RELOC(cpu) # set CPU type
345: /*
346: * Check for Cyrix 486 CPU by seeing if the flags change during a
347: * divide. This is documented in the Cx486SLC/e SMM Programmer's
348: * Guide.
349: */
350: xorl %edx,%edx
351: cmpl %edx,%edx # set flags to known state
352: pushfl
353: popl %ecx # store flags in ecx
354: movl $-1,%eax
355: movl $4,%ebx
356: divl %ebx # do a long division
357: pushfl
358: popl %eax
359: xorl %ecx,%eax # are the flags different?
360: testl $0x8d5,%eax # only check C|PF|AF|Z|N|V
361: jne 2f # yes; must be Cyrix 6x86 CPU
362: movl $CPU_486DLC,RELOC(cpu) # set CPU type
363:
364: #ifndef CYRIX_CACHE_WORKS
365: /* Disable caching of the ISA hole only. */
366: invd
367: movb $CCR0,%al # Configuration Register index (CCR0)
368: outb %al,$0x22
369: inb $0x23,%al
370: orb $(CCR0_NC1|CCR0_BARB),%al
371: movb %al,%ah
372: movb $CCR0,%al
373: outb %al,$0x22
374: movb %ah,%al
375: outb %al,$0x23
376: invd
377: #else /* CYRIX_CACHE_WORKS */
378: /* Set cache parameters */
379: invd # Start with guaranteed clean cache
380: movb $CCR0,%al # Configuration Register index (CCR0)
381: outb %al,$0x22
382: inb $0x23,%al
383: andb $~CCR0_NC0,%al
384: #ifndef CYRIX_CACHE_REALLY_WORKS
385: orb $(CCR0_NC1|CCR0_BARB),%al
386: #else
387: orb $CCR0_NC1,%al
388: #endif
389: movb %al,%ah
390: movb $CCR0,%al
391: outb %al,$0x22
392: movb %ah,%al
393: outb %al,$0x23
394: /* clear non-cacheable region 1 */
395: movb $(NCR1+2),%al
396: outb %al,$0x22
397: movb $NCR_SIZE_0K,%al
398: outb %al,$0x23
399: /* clear non-cacheable region 2 */
400: movb $(NCR2+2),%al
401: outb %al,$0x22
402: movb $NCR_SIZE_0K,%al
403: outb %al,$0x23
404: /* clear non-cacheable region 3 */
405: movb $(NCR3+2),%al
406: outb %al,$0x22
407: movb $NCR_SIZE_0K,%al
408: outb %al,$0x23
409: /* clear non-cacheable region 4 */
410: movb $(NCR4+2),%al
411: outb %al,$0x22
412: movb $NCR_SIZE_0K,%al
413: outb %al,$0x23
414: /* enable caching in CR0 */
415: movl %cr0,%eax
416: andl $~(CR0_CD|CR0_NW),%eax
417: movl %eax,%cr0
418: invd
419: #endif /* CYRIX_CACHE_WORKS */
420:
421: jmp 2f
422:
423: try586: /* Use the `cpuid' instruction. */
424: xorl %eax,%eax
425: cpuid
426: movl %eax,RELOC(cpu_info_primary)+CPU_INFO_LEVEL
427:
428: 2:
429: /*
430: * Finished with old stack; load new %esp now instead of later so we
431: * can trace this code without having to worry about the trace trap
432: * clobbering the memory test or the zeroing of the bss+bootstrap page
433: * tables.
434: *
435: * The boot program should check:
436: * text+data <= &stack_variable - more_space_for_stack
437: * text+data+bss+pad+space_for_page_tables <= end_of_memory
438: * Oops, the gdt is in the carcass of the boot program so clearing
439: * the rest of memory is still not possible.
440: */
441: movl $_RELOC(tmpstk),%esp # bootstrap stack end location
442:
443: /*
444: * Virtual address space of kernel:
445: *
1.30 junyoung 446: * text | data | bss | [syms] | page dir | proc0 kstack
1.1 fvdl 447: * 0 1 2 3
448: */
1.7 thorpej 449: #define PROC0PDIR ((0) * PAGE_SIZE)
450: #define PROC0STACK ((1) * PAGE_SIZE)
451: #define SYSMAP ((1+UPAGES) * PAGE_SIZE)
452: #define TABLESIZE ((1+UPAGES) * PAGE_SIZE) /* + nkpde * PAGE_SIZE */
1.1 fvdl 453:
454: /* Find end of kernel image. */
455: movl $RELOC(end),%edi
1.8 fvdl 456: #if (NKSYMS || defined(DDB) || defined(LKM)) && !defined(SYMTAB_SPACE)
1.1 fvdl 457: /* Save the symbols (if loaded). */
458: movl RELOC(esym),%eax
459: testl %eax,%eax
460: jz 1f
1.35 yamt 461: subl $KERNBASE,%eax
1.1 fvdl 462: movl %eax,%edi
463: 1:
464: #endif
465:
466: /* Calculate where to start the bootstrap tables. */
467: movl %edi,%esi # edi = esym ? esym : end
468: addl $PGOFSET,%esi # page align up
469: andl $~PGOFSET,%esi
470:
471: /*
472: * Calculate the size of the kernel page table directory, and
1.29 mycroft 473: * how many entries it will have. Adjust nkpde to the actual
474: * kernel size automatically. Account for the bootstrap tables,
475: * round up, and add an extra 4MB.
1.1 fvdl 476: */
1.29 mycroft 477: leal TABLESIZE+NBPD+PDOFSET(%edi),%eax
478: shrl $PDSHIFT,%eax
1.1 fvdl 479: movl RELOC(nkpde),%ecx # get nkpde
1.29 mycroft 480: cmpl %ecx,%eax
481: jb 1f
482: movl %eax,%ecx
483: 1: cmpl $NKPTP_MIN,%ecx # larger than min?
1.1 fvdl 484: jge 1f
485: movl $NKPTP_MIN,%ecx # set at min
486: jmp 2f
487: 1: cmpl $NKPTP_MAX,%ecx # larger than max?
488: jle 2f
489: movl $NKPTP_MAX,%ecx
1.29 mycroft 490: 2: movl %ecx,RELOC(nkpde)
1.1 fvdl 491:
492: /* Clear memory for bootstrap tables. */
493: shll $PGSHIFT,%ecx
494: addl $TABLESIZE,%ecx
495: addl %esi,%ecx # end of tables
496: subl %edi,%ecx # size of tables
497: shrl $2,%ecx
498: xorl %eax,%eax
499: cld
500: rep
501: stosl
502:
503: /*
504: * fillkpt
505: * eax = pte (page frame | control | status)
506: * ebx = page table address
507: * ecx = number of pages to map
508: */
509: #define fillkpt \
510: 1: movl %eax,(%ebx) ; \
1.7 thorpej 511: addl $PAGE_SIZE,%eax ; /* increment physical address */ \
1.1 fvdl 512: addl $4,%ebx ; /* next pte */ \
513: loop 1b ;
514:
515: /*
516: * Build initial page tables.
517: */
518: /* Calculate end of text segment, rounded to a page. */
519: leal (RELOC(etext)+PGOFSET),%edx
520: andl $~PGOFSET,%edx
1.30 junyoung 521:
1.1 fvdl 522: /* Skip over the first 1MB. */
523: movl $_RELOC(KERNTEXTOFF),%eax
524: movl %eax,%ecx
525: shrl $PGSHIFT,%ecx
526: leal (SYSMAP)(%esi,%ecx,4),%ebx
527:
528: /* Map the kernel text read-only. */
529: movl %edx,%ecx
530: subl %eax,%ecx
531: shrl $PGSHIFT,%ecx
532: orl $(PG_V|PG_KR),%eax
533: fillkpt
534:
535: /* Map the data, BSS, and bootstrap tables read-write. */
536: leal (PG_V|PG_KW)(%edx),%eax
537: movl RELOC(nkpde),%ecx
538: shll $PGSHIFT,%ecx
539: addl $TABLESIZE,%ecx
540: addl %esi,%ecx # end of tables
541: subl %edx,%ecx # subtract end of text
542: shrl $PGSHIFT,%ecx
543: fillkpt
544:
545: /* Map ISA I/O memory. */
546: movl $(IOM_BEGIN|PG_V|PG_KW/*|PG_N*/),%eax # having these bits set
547: movl $(IOM_SIZE>>PGSHIFT),%ecx # for this many pte s,
548: fillkpt
549:
550: /*
551: * Construct a page table directory.
552: */
553: /* Install PDEs for temporary double map of kernel. */
554: movl RELOC(nkpde),%ecx # for this many pde s,
555: leal (PROC0PDIR+0*4)(%esi),%ebx # which is where temp maps!
556: leal (SYSMAP+PG_V|PG_KW)(%esi),%eax # pte for KPT in proc 0,
557: fillkpt
558:
559: /* Map kernel PDEs. */
560: movl RELOC(nkpde),%ecx # for this many pde s,
561: leal (PROC0PDIR+PDSLOT_KERN*4)(%esi),%ebx # kernel pde offset
562: leal (SYSMAP+PG_V|PG_KW)(%esi),%eax # pte for KPT in proc 0,
563: fillkpt
564:
565: /* Install a PDE recursively mapping page directory as a page table! */
566: leal (PROC0PDIR+PG_V|PG_KW)(%esi),%eax # pte for ptd
567: movl %eax,(PROC0PDIR+PDSLOT_PTE*4)(%esi) # recursive PD slot
568:
1.31 junyoung 569: /* Save phys. addr of PDP, for libkvm. */
570: movl %esi,RELOC(PDPpaddr)
1.1 fvdl 571:
572: /* Load base of page directory and enable mapping. */
573: movl %esi,%eax # phys address of ptd in proc 0
574: movl %eax,%cr3 # load ptd addr into mmu
575: movl %cr0,%eax # get control word
576: # enable paging & NPX emulation
577: orl $(CR0_PE|CR0_PG|CR0_NE|CR0_TS|CR0_EM|CR0_MP),%eax
578: movl %eax,%cr0 # and let's page NOW!
579:
580: pushl $begin # jump to high mem
581: ret
582:
583: begin:
1.35 yamt 584: /* Now running relocated at KERNBASE. Remove double mapping. */
1.1 fvdl 585: movl _C_LABEL(nkpde),%ecx # for this many pde s,
586: leal (PROC0PDIR+0*4)(%esi),%ebx # which is where temp maps!
1.35 yamt 587: addl $(KERNBASE), %ebx # now use relocated address
1.1 fvdl 588: 1: movl $0,(%ebx)
589: addl $4,%ebx # next pde
590: loop 1b
591:
592: /* Relocate atdevbase. */
593: movl _C_LABEL(nkpde),%edx
594: shll $PGSHIFT,%edx
1.35 yamt 595: addl $(TABLESIZE+KERNBASE),%edx
1.1 fvdl 596: addl %esi,%edx
597: movl %edx,_C_LABEL(atdevbase)
598:
599: /* Set up bootstrap stack. */
1.35 yamt 600: leal (PROC0STACK+KERNBASE)(%esi),%eax
1.40 yamt 601: movl %eax,_C_LABEL(proc0uarea)
602: leal (KSTACK_SIZE-FRAMESIZE)(%eax),%esp
603: movl %esi,(KSTACK_SIZE+PCB_CR3)(%eax) # pcb->pcb_cr3
1.1 fvdl 604: xorl %ebp,%ebp # mark end of frames
605:
1.37 jmmv 606: #if defined(MULTIBOOT)
607: /* It is now safe to parse the Multiboot information structure
608: * we saved before from C code. Note that we cannot delay its
609: * parsing any more because initgdt (called below) needs to make
610: * use of this information. */
611: call _C_LABEL(multiboot_post_reloc)
612: #endif
613:
1.1 fvdl 614: subl $NGDT*8, %esp # space for temporary gdt
615: pushl %esp
616: call _C_LABEL(initgdt)
617: addl $4,%esp
1.30 junyoung 618:
1.1 fvdl 619: movl _C_LABEL(nkpde),%eax
620: shll $PGSHIFT,%eax
621: addl $TABLESIZE,%eax
622: addl %esi,%eax # skip past stack and page tables
623:
624: pushl %eax
625: call _C_LABEL(init386) # wire 386 chip for unix operation
626: addl $4+NGDT*8,%esp # pop temporary gdt
627:
628: #ifdef SAFARI_FIFO_HACK
629: movb $5,%al
630: movw $0x37b,%dx
631: outb %al,%dx
632: movw $0x37f,%dx
633: inb %dx,%al
634: movb %al,%cl
635:
636: orb $1,%cl
637:
638: movb $5,%al
639: movw $0x37b,%dx
640: outb %al,%dx
641: movw $0x37f,%dx
642: movb %cl,%al
643: outb %al,%dx
644: #endif /* SAFARI_FIFO_HACK */
645:
646: call _C_LABEL(main)
647:
648: /*
649: * void proc_trampoline(void);
650: * This is a trampoline function pushed onto the stack of a newly created
651: * process in order to do some additional setup. The trampoline is entered by
652: * cpu_switch()ing to the process, so we abuse the callee-saved registers used
653: * by cpu_switch() to store the information about the stub to call.
654: * NOTE: This function does not have a normal calling sequence!
655: */
656: /* LINTSTUB: Func: void proc_trampoline(void) */
657: NENTRY(proc_trampoline)
658: #ifdef MULTIPROCESSOR
659: call _C_LABEL(proc_trampoline_mp)
660: #endif
661: movl $IPL_NONE,CPUVAR(ILEVEL)
662: pushl %ebx
663: call *%esi
664: addl $4,%esp
1.24 yamt 665: DO_DEFERRED_SWITCH(%eax)
1.1 fvdl 666: INTRFASTEXIT
667: /* NOTREACHED */
668:
669: /*****************************************************************************/
1.16 christos 670: #ifdef COMPAT_16
1.1 fvdl 671: /*
672: * Signal trampoline; copied to top of user stack.
673: */
674: /* LINTSTUB: Var: char sigcode[1], esigcode[1]; */
675: NENTRY(sigcode)
676: /*
677: * Handler has returned here as if we called it. The sigcontext
678: * is on the stack after the 3 args "we" pushed.
679: */
680: leal 12(%esp),%eax # get pointer to sigcontext
681: movl %eax,4(%esp) # put it in the argument slot
682: # fake return address already there
1.17 christos 683: movl $SYS_compat_16___sigreturn14,%eax
1.1 fvdl 684: int $0x80 # enter kernel with args on stack
685: movl $SYS_exit,%eax
686: int $0x80 # exit if sigreturn fails
687: .globl _C_LABEL(esigcode)
688: _C_LABEL(esigcode):
1.16 christos 689: #endif
1.1 fvdl 690:
691: /*****************************************************************************/
692:
693: /*
694: * The following is i386-specific nonsense.
695: */
696:
697: /*
698: * void lgdt(struct region_descriptor *rdp);
699: * Load a new GDT pointer (and do any necessary cleanup).
700: * XXX It's somewhat questionable whether reloading all the segment registers
701: * is necessary, since the actual descriptor data is not changed except by
702: * process creation and exit, both of which clean up via task switches. OTOH,
703: * this only happens at run time when the GDT is resized.
704: */
705: /* LINTSTUB: Func: void lgdt(struct region_descriptor *rdp) */
706: NENTRY(lgdt)
707: /* Reload the descriptor table. */
708: movl 4(%esp),%eax
709: lgdt (%eax)
710: /* Flush the prefetch queue. */
711: jmp 1f
712: nop
713: 1: /* Reload "stale" selectors. */
714: movl $GSEL(GDATA_SEL, SEL_KPL),%eax
715: movw %ax,%ds
716: movw %ax,%es
717: movw %ax,%gs
718: movw %ax,%ss
719: movl $GSEL(GCPU_SEL, SEL_KPL),%eax
720: movw %ax,%fs
721: /* Reload code selector by doing intersegment return. */
722: popl %eax
723: pushl $GSEL(GCODE_SEL, SEL_KPL)
724: pushl %eax
725: lret
726:
727: /*****************************************************************************/
728:
729: /*
730: * These functions are primarily used by DDB.
731: */
732:
733: /* LINTSTUB: Func: int setjmp (label_t *l) */
734: ENTRY(setjmp)
735: movl 4(%esp),%eax
736: movl %ebx,(%eax) # save ebx
737: movl %esp,4(%eax) # save esp
738: movl %ebp,8(%eax) # save ebp
739: movl %esi,12(%eax) # save esi
740: movl %edi,16(%eax) # save edi
741: movl (%esp),%edx # get rta
742: movl %edx,20(%eax) # save eip
743: xorl %eax,%eax # return (0);
744: ret
745:
746: /* LINTSTUB: Func: void longjmp (label_t *l) */
747: ENTRY(longjmp)
748: movl 4(%esp),%eax
749: movl (%eax),%ebx # restore ebx
750: movl 4(%eax),%esp # restore esp
751: movl 8(%eax),%ebp # restore ebp
752: movl 12(%eax),%esi # restore esi
753: movl 16(%eax),%edi # restore edi
754: movl 20(%eax),%edx # get rta
755: movl %edx,(%esp) # put in return frame
756: xorl %eax,%eax # return (1);
757: incl %eax
758: ret
759:
760: /*****************************************************************************/
761:
762: .globl _C_LABEL(sched_whichqs),_C_LABEL(sched_qs)
763: .globl _C_LABEL(uvmexp),_C_LABEL(panic)
764:
765: #ifdef DIAGNOSTIC
766: NENTRY(switch_error)
767: pushl $1f
768: call _C_LABEL(panic)
769: /* NOTREACHED */
770: 1: .asciz "cpu_switch"
771: #endif /* DIAGNOSTIC */
772:
773: /*
1.5 thorpej 774: * void cpu_switch(struct lwp *)
1.39 skrll 775: * Find a runnable lwp and switch to it. Wait if necessary. If the new
776: * lwp is the same as the old one, we short-circuit the context save and
1.1 fvdl 777: * restore.
1.30 junyoung 778: *
1.1 fvdl 779: * Note that the stack frame layout is known to "struct switchframe"
1.30 junyoung 780: * in <machine/frame.h> and to the code in cpu_fork() which initializes
1.5 thorpej 781: * it for a new lwp.
1.1 fvdl 782: */
783: ENTRY(cpu_switch)
784: pushl %ebx
785: pushl %esi
786: pushl %edi
787:
788: #ifdef DEBUG
789: cmpl $IPL_SCHED,CPUVAR(ILEVEL)
790: jae 1f
1.5 thorpej 791: pushl $2f
1.1 fvdl 792: call _C_LABEL(panic)
793: /* NOTREACHED */
1.5 thorpej 794: 2: .asciz "not splsched() in cpu_switch!"
1.30 junyoung 795: 1:
1.1 fvdl 796: #endif /* DEBUG */
1.30 junyoung 797:
1.5 thorpej 798: movl 16(%esp),%esi # current
1.1 fvdl 799:
800: /*
1.5 thorpej 801: * Clear curlwp so that we don't accumulate system time while idle.
802: * This also insures that schedcpu() will move the old lwp to
1.1 fvdl 803: * the correct queue if it happens to get called from the spllower()
804: * below and changes the priority. (See corresponding comment in
805: * userret()).
806: */
1.5 thorpej 807: movl $0,CPUVAR(CURLWP)
1.1 fvdl 808: /*
1.5 thorpej 809: * First phase: find new lwp.
1.1 fvdl 810: *
811: * Registers:
812: * %eax - queue head, scratch, then zero
813: * %ebx - queue number
814: * %ecx - cached value of whichqs
1.5 thorpej 815: * %edx - next lwp in queue
816: * %esi - old lwp
817: * %edi - new lwp
1.1 fvdl 818: */
819:
1.5 thorpej 820: /* Look for new lwp. */
1.1 fvdl 821: cli # splhigh doesn't do a cli
822: movl _C_LABEL(sched_whichqs),%ecx
823: bsfl %ecx,%ebx # find a full q
824: jnz switch_dequeue
825:
826: /*
827: * idling: save old context.
828: *
829: * Registers:
830: * %eax, %ecx - scratch
1.5 thorpej 831: * %esi - old lwp, then old pcb
1.1 fvdl 832: * %edi - idle pcb
833: */
834:
835: pushl %esi
1.24 yamt 836: call _C_LABEL(pmap_deactivate2) # pmap_deactivate(oldproc)
1.1 fvdl 837: addl $4,%esp
838:
1.5 thorpej 839: movl L_ADDR(%esi),%esi
1.1 fvdl 840:
841: /* Save stack pointers. */
842: movl %esp,PCB_ESP(%esi)
843: movl %ebp,PCB_EBP(%esi)
844:
845: /* Find idle PCB for this CPU */
846: #ifndef MULTIPROCESSOR
1.5 thorpej 847: movl $_C_LABEL(lwp0),%ebx
848: movl L_ADDR(%ebx),%edi
849: movl L_MD_TSS_SEL(%ebx),%edx
1.1 fvdl 850: #else
851: movl CPUVAR(IDLE_PCB),%edi
852: movl CPUVAR(IDLE_TSS_SEL),%edx
853: #endif
1.5 thorpej 854: movl $0,CPUVAR(CURLWP) /* In case we fault... */
1.1 fvdl 855:
856: /* Restore the idle context (avoid interrupts) */
857: cli
858:
859: /* Restore stack pointers. */
860: movl PCB_ESP(%edi),%esp
861: movl PCB_EBP(%edi),%ebp
862:
863: /* Switch TSS. Reset "task busy" flag before loading. */
1.26 yamt 864: movl %cr3,%eax
865: movl %eax,PCB_CR3(%edi)
1.1 fvdl 866: #ifdef MULTIPROCESSOR
867: movl CPUVAR(GDT),%eax
868: #else
869: movl _C_LABEL(gdt),%eax
870: #endif
871: andl $~0x0200,4-SEL_KPL(%eax,%edx,1)
872: ltr %dx
873:
874: /* We're always in the kernel, so we don't need the LDT. */
875:
876: /* Restore cr0 (including FPU state). */
877: movl PCB_CR0(%edi),%ecx
878: movl %ecx,%cr0
879:
880: /* Record new pcb. */
881: SET_CURPCB(%edi)
882:
883: xorl %esi,%esi
884: sti
1.30 junyoung 885: idle_unlock:
886: #if defined(MULTIPROCESSOR) || defined(LOCKDEBUG)
1.1 fvdl 887: call _C_LABEL(sched_unlock_idle)
888: #endif
889: /* Interrupts are okay again. */
1.2 fvdl 890: pushl $IPL_NONE # spl0()
1.1 fvdl 891: call _C_LABEL(Xspllower) # process pending interrupts
1.2 fvdl 892: addl $4,%esp
1.1 fvdl 893: jmp idle_start
1.30 junyoung 894: idle_zero:
1.1 fvdl 895: sti
896: call _C_LABEL(uvm_pageidlezero)
897: cli
898: cmpl $0,_C_LABEL(sched_whichqs)
899: jnz idle_exit
900: idle_loop:
901: /* Try to zero some pages. */
902: movl _C_LABEL(uvm)+UVM_PAGE_IDLE_ZERO,%ecx
903: testl %ecx,%ecx
904: jnz idle_zero
905: sti
906: hlt
907: NENTRY(mpidle)
1.30 junyoung 908: idle_start:
1.1 fvdl 909: cli
910: cmpl $0,_C_LABEL(sched_whichqs)
911: jz idle_loop
1.30 junyoung 912: idle_exit:
1.1 fvdl 913: movl $IPL_HIGH,CPUVAR(ILEVEL) # splhigh
1.14 fvdl 914: sti
1.30 junyoung 915: #if defined(MULTIPROCESSOR) || defined(LOCKDEBUG)
1.1 fvdl 916: call _C_LABEL(sched_lock_idle)
917: #endif
918: movl _C_LABEL(sched_whichqs),%ecx
919: bsfl %ecx,%ebx
920: jz idle_unlock
921:
1.30 junyoung 922: switch_dequeue:
923: /*
1.1 fvdl 924: * we're running at splhigh(), but it's otherwise okay to take
1.30 junyoung 925: * interrupts here.
1.1 fvdl 926: */
927: sti
928: leal _C_LABEL(sched_qs)(,%ebx,8),%eax # select q
929:
1.5 thorpej 930: movl L_FORW(%eax),%edi # unlink from front of process q
1.1 fvdl 931: #ifdef DIAGNOSTIC
932: cmpl %edi,%eax # linked to self (i.e. nothing queued)?
933: je _C_LABEL(switch_error) # not possible
934: #endif /* DIAGNOSTIC */
1.5 thorpej 935: movl L_FORW(%edi),%edx
936: movl %edx,L_FORW(%eax)
937: movl %eax,L_BACK(%edx)
1.1 fvdl 938:
939: cmpl %edx,%eax # q empty?
940: jne 3f
941:
942: btrl %ebx,%ecx # yes, clear to indicate empty
943: movl %ecx,_C_LABEL(sched_whichqs) # update q status
944:
945: 3: /* We just did it. */
946: xorl %eax,%eax
947: CLEAR_RESCHED(%eax)
948:
1.5 thorpej 949: switch_resume:
1.1 fvdl 950: #ifdef DIAGNOSTIC
1.5 thorpej 951: cmpl %eax,L_WCHAN(%edi) # Waiting for something?
1.1 fvdl 952: jne _C_LABEL(switch_error) # Yes; shouldn't be queued.
1.5 thorpej 953: cmpb $LSRUN,L_STAT(%edi) # In run state?
1.1 fvdl 954: jne _C_LABEL(switch_error) # No; shouldn't be queued.
955: #endif /* DIAGNOSTIC */
956:
1.5 thorpej 957: /* Isolate lwp. XXX Is this necessary? */
958: movl %eax,L_BACK(%edi)
1.1 fvdl 959:
1.5 thorpej 960: /* Record new lwp. */
961: movb $LSONPROC,L_STAT(%edi) # l->l_stat = LSONPROC
962: SET_CURLWP(%edi,%ecx)
1.1 fvdl 963:
1.5 thorpej 964: /* Skip context switch if same lwp. */
1.10 fvdl 965: xorl %ebx,%ebx
1.1 fvdl 966: cmpl %edi,%esi
967: je switch_return
968:
1.5 thorpej 969: /* If old lwp exited, don't bother. */
1.1 fvdl 970: testl %esi,%esi
971: jz switch_exited
972:
973: /*
974: * Second phase: save old context.
975: *
976: * Registers:
977: * %eax, %ecx - scratch
1.5 thorpej 978: * %esi - old lwp, then old pcb
979: * %edi - new lwp
1.1 fvdl 980: */
981:
982: pushl %esi
1.24 yamt 983: call _C_LABEL(pmap_deactivate2) # pmap_deactivate(oldproc)
1.1 fvdl 984: addl $4,%esp
985:
1.5 thorpej 986: movl L_ADDR(%esi),%esi
1.1 fvdl 987:
988: /* Save stack pointers. */
989: movl %esp,PCB_ESP(%esi)
990: movl %ebp,PCB_EBP(%esi)
991:
992: switch_exited:
993: /*
994: * Third phase: restore saved context.
995: *
996: * Registers:
997: * %eax, %ebx, %ecx, %edx - scratch
998: * %esi - new pcb
1.5 thorpej 999: * %edi - new lwp
1.1 fvdl 1000: */
1001:
1002: /* No interrupts while loading new state. */
1003: cli
1.5 thorpej 1004: movl L_ADDR(%edi),%esi
1.1 fvdl 1005:
1006: /* Restore stack pointers. */
1007: movl PCB_ESP(%esi),%esp
1008: movl PCB_EBP(%esi),%ebp
1009:
1010: #if 0
1011: /* Don't bother with the rest if switching to a system process. */
1.5 thorpej 1012: testl $P_SYSTEM,L_FLAG(%edi); XXX NJWLWP lwp's don't have P_SYSTEM!
1.1 fvdl 1013: jnz switch_restored
1014: #endif
1015:
1.26 yamt 1016: /* Switch TSS. Reset "task busy" flag before loading. */
1017: movl %cr3,%eax
1018: movl %eax,PCB_CR3(%esi) /* XXX should be done by pmap_activate? */
1.1 fvdl 1019: #ifdef MULTIPROCESSOR
1020: movl CPUVAR(GDT),%eax
1.30 junyoung 1021: #else
1.1 fvdl 1022: /* Load TSS info. */
1023: movl _C_LABEL(gdt),%eax
1024: #endif
1.5 thorpej 1025: movl L_MD_TSS_SEL(%edi),%edx
1.1 fvdl 1026:
1027: andl $~0x0200,4(%eax,%edx, 1)
1028: ltr %dx
1029:
1030: pushl %edi
1031: call _C_LABEL(pmap_activate) # pmap_activate(p)
1032: addl $4,%esp
1033:
1034: #if 0
1035: switch_restored:
1036: #endif
1037: /* Restore cr0 (including FPU state). */
1038: movl PCB_CR0(%esi),%ecx
1039: #ifdef MULTIPROCESSOR
1.30 junyoung 1040: /*
1.22 wiz 1041: * If our floating point registers are on a different CPU,
1.1 fvdl 1042: * clear CR0_TS so we'll trap rather than reuse bogus state.
1043: */
1044: movl PCB_FPCPU(%esi),%ebx
1045: cmpl CPUVAR(SELF),%ebx
1046: jz 1f
1047: orl $CR0_TS,%ecx
1.30 junyoung 1048: 1:
1049: #endif
1.1 fvdl 1050: movl %ecx,%cr0
1051:
1052: /* Record new pcb. */
1053: SET_CURPCB(%esi)
1054:
1055: /* Interrupts are okay again. */
1056: sti
1057:
1058: /*
1059: * Check for restartable atomic sequences (RAS)
1060: */
1.5 thorpej 1061: movl CPUVAR(CURLWP),%edi
1062: movl L_PROC(%edi),%esi
1.20 dsl 1063: cmpl $0,P_RASLIST(%esi)
1064: jne 2f
1.1 fvdl 1065: 1:
1.10 fvdl 1066: movl $1,%ebx
1.1 fvdl 1067:
1068: switch_return:
1.30 junyoung 1069: #if defined(MULTIPROCESSOR) || defined(LOCKDEBUG)
1.1 fvdl 1070: call _C_LABEL(sched_unlock_idle)
1071: #endif
1.28 yamt 1072: cmpl $0,CPUVAR(IPENDING)
1073: jz 3f
1.2 fvdl 1074: pushl $IPL_NONE # spl0()
1.1 fvdl 1075: call _C_LABEL(Xspllower) # process pending interrupts
1.2 fvdl 1076: addl $4,%esp
1.28 yamt 1077: 3:
1.1 fvdl 1078: movl $IPL_HIGH,CPUVAR(ILEVEL) # splhigh()
1.9 fvdl 1079:
1080: movl %ebx,%eax
1.30 junyoung 1081:
1.1 fvdl 1082: popl %edi
1083: popl %esi
1084: popl %ebx
1085: ret
1.20 dsl 1086:
1087: 2: # check RAS list
1088: movl L_MD_REGS(%edi),%ebx
1089: movl TF_EIP(%ebx),%eax
1090: pushl %eax
1091: pushl %esi
1092: call _C_LABEL(ras_lookup)
1093: addl $8,%esp
1094: cmpl $-1,%eax
1095: je 1b
1096: movl %eax,TF_EIP(%ebx)
1097: jmp 1b
1.1 fvdl 1098:
1099: /*
1.5 thorpej 1100: * void cpu_switchto(struct lwp *current, struct lwp *next)
1101: * Switch to the specified next LWP.
1102: */
1103: ENTRY(cpu_switchto)
1104: pushl %ebx
1105: pushl %esi
1106: pushl %edi
1107:
1108: #ifdef DEBUG
1109: cmpl $IPL_SCHED,CPUVAR(ILEVEL)
1110: jae 1f
1111: pushl $2f
1112: call _C_LABEL(panic)
1113: /* NOTREACHED */
1114: 2: .asciz "not splsched() in cpu_switchto!"
1115: 1:
1116: #endif /* DEBUG */
1117:
1118: movl 16(%esp),%esi # current
1119: movl 20(%esp),%edi # next
1120:
1121: /*
1122: * Clear curlwp so that we don't accumulate system time while idle.
1123: * This also insures that schedcpu() will move the old process to
1124: * the correct queue if it happens to get called from the spllower()
1125: * below and changes the priority. (See corresponding comment in
1126: * usrret()).
1127: *
1128: * XXX Is this necessary? We know we won't go idle.
1129: */
1130: movl $0,CPUVAR(CURLWP)
1131:
1132: /*
1133: * We're running at splhigh(), but it's otherwise okay to take
1134: * interrupts here.
1135: */
1136: sti
1137:
1138: /* Jump into the middle of cpu_switch */
1139: xorl %eax,%eax
1140: jmp switch_resume
1141:
1142: /*
1.21 jdolecek 1143: * void cpu_exit(struct lwp *l)
1.30 junyoung 1144: * Switch to the appropriate idle context (lwp0's if uniprocessor; the CPU's
1145: * if multiprocessor) and deallocate the address space and kernel stack for p.
1.1 fvdl 1146: * Then jump into cpu_switch(), as if we were in the idle proc all along.
1147: */
1148: #ifndef MULTIPROCESSOR
1.5 thorpej 1149: .globl _C_LABEL(lwp0)
1.1 fvdl 1150: #endif
1.21 jdolecek 1151: /* LINTSTUB: Func: void cpu_exit(struct lwp *l) */
1152: ENTRY(cpu_exit)
1.1 fvdl 1153: movl 4(%esp),%edi # old process
1154: #ifndef MULTIPROCESSOR
1.5 thorpej 1155: movl $_C_LABEL(lwp0),%ebx
1156: movl L_ADDR(%ebx),%esi
1157: movl L_MD_TSS_SEL(%ebx),%edx
1.1 fvdl 1158: #else
1159: movl CPUVAR(IDLE_PCB),%esi
1160: movl CPUVAR(IDLE_TSS_SEL),%edx
1161: #endif
1162: /* In case we fault... */
1.5 thorpej 1163: movl $0,CPUVAR(CURLWP)
1.1 fvdl 1164:
1165: /* Restore the idle context. */
1166: cli
1167:
1168: /* Restore stack pointers. */
1169: movl PCB_ESP(%esi),%esp
1170: movl PCB_EBP(%esi),%ebp
1171:
1.26 yamt 1172: /* Switch TSS. Reset "task busy" flag before loading. */
1173: movl %cr3,%eax
1174: movl %eax,PCB_CR3(%esi)
1.1 fvdl 1175: #ifdef MULTIPROCESSOR
1176: movl CPUVAR(GDT),%eax
1.30 junyoung 1177: #else
1.1 fvdl 1178: /* Load TSS info. */
1179: movl _C_LABEL(gdt),%eax
1180: #endif
1181:
1182: andl $~0x0200,4-SEL_KPL(%eax,%edx,1)
1183: ltr %dx
1184:
1185: /* We're always in the kernel, so we don't need the LDT. */
1186:
1187: /* Restore cr0 (including FPU state). */
1188: movl PCB_CR0(%esi),%ecx
1189: movl %ecx,%cr0
1190:
1191: /* Record new pcb. */
1192: SET_CURPCB(%esi)
1193:
1194: /* Interrupts are okay again. */
1195: sti
1196:
1197: /*
1.21 jdolecek 1198: * Schedule the dead LWP's stack to be freed.
1.1 fvdl 1199: */
1.21 jdolecek 1200: pushl %edi
1201: call _C_LABEL(lwp_exit2)
1.1 fvdl 1202: addl $4,%esp
1203:
1204: /* Jump into cpu_switch() with the right state. */
1205: xorl %esi,%esi
1.5 thorpej 1206: movl %esi,CPUVAR(CURLWP)
1.1 fvdl 1207: jmp idle_start
1208:
1209: /*
1210: * void savectx(struct pcb *pcb);
1211: * Update pcb, saving current processor state.
1212: */
1213: /* LINTSTUB: Func: void savectx(struct pcb *pcb) */
1214: ENTRY(savectx)
1215: movl 4(%esp),%edx # edx = p->p_addr
1.30 junyoung 1216:
1.1 fvdl 1217: /* Save stack pointers. */
1218: movl %esp,PCB_ESP(%edx)
1219: movl %ebp,PCB_EBP(%edx)
1220:
1221: ret
1222:
1223: /*
1224: * Old call gate entry for syscall
1225: */
1226: /* LINTSTUB: Var: char Xosyscall[1]; */
1227: IDTVEC(osyscall)
1228: /* Set eflags in trap frame. */
1229: pushfl
1230: popl 8(%esp)
1231: pushl $7 # size of instruction for restart
1232: jmp syscall1
1233:
1234: /*
1235: * Trap gate entry for syscall
1236: */
1237: /* LINTSTUB: Var: char Xsyscall[1]; */
1238: IDTVEC(syscall)
1239: pushl $2 # size of instruction for restart
1240: syscall1:
1241: pushl $T_ASTFLT # trap # for doing ASTs
1242: INTRENTRY
1243:
1244: #ifdef DIAGNOSTIC
1.24 yamt 1245: cmpl $0, CPUVAR(WANT_PMAPLOAD)
1246: jz 1f
1247: pushl $6f
1248: call _C_LABEL(printf)
1249: addl $4, %esp
1250: 1:
1.1 fvdl 1251: movl CPUVAR(ILEVEL),%ebx
1252: testl %ebx,%ebx
1253: jz 1f
1254: pushl $5f
1255: call _C_LABEL(printf)
1256: addl $4,%esp
1257: #ifdef DDB
1258: int $3
1259: #endif
1.30 junyoung 1260: 1:
1.1 fvdl 1261: #endif /* DIAGNOSTIC */
1.5 thorpej 1262: movl CPUVAR(CURLWP),%edx
1263: movl %esp,L_MD_REGS(%edx) # save pointer to frame
1264: movl L_PROC(%edx),%edx
1.15 fvdl 1265: pushl %esp
1.1 fvdl 1266: call *P_MD_SYSCALL(%edx) # get pointer to syscall() function
1.15 fvdl 1267: addl $4,%esp
1.27 yamt 1268: .Lsyscall_checkast:
1.24 yamt 1269: /* Check for ASTs on exit to user mode. */
1.1 fvdl 1270: cli
1.5 thorpej 1271: CHECK_ASTPENDING(%eax)
1.1 fvdl 1272: je 1f
1273: /* Always returning to user mode here. */
1.5 thorpej 1274: CLEAR_ASTPENDING(%eax)
1.1 fvdl 1275: sti
1276: /* Pushed T_ASTFLT into tf_trapno on entry. */
1.15 fvdl 1277: pushl %esp
1.1 fvdl 1278: call _C_LABEL(trap)
1.15 fvdl 1279: addl $4,%esp
1.27 yamt 1280: jmp .Lsyscall_checkast /* re-check ASTs */
1.24 yamt 1281: 1: CHECK_DEFERRED_SWITCH(%eax)
1282: jnz 9f
1.1 fvdl 1283: #ifndef DIAGNOSTIC
1.24 yamt 1284: INTRFASTEXIT
1.1 fvdl 1285: #else /* DIAGNOSTIC */
1.24 yamt 1286: cmpl $IPL_NONE,CPUVAR(ILEVEL)
1.1 fvdl 1287: jne 3f
1288: INTRFASTEXIT
1289: 3: sti
1290: pushl $4f
1291: call _C_LABEL(printf)
1292: addl $4,%esp
1293: #ifdef DDB
1294: int $3
1295: #endif /* DDB */
1296: movl $IPL_NONE,CPUVAR(ILEVEL)
1297: jmp 2b
1298: 4: .asciz "WARNING: SPL NOT LOWERED ON SYSCALL EXIT\n"
1.30 junyoung 1299: 5: .asciz "WARNING: SPL NOT ZERO ON SYSCALL ENTRY\n"
1300: 6: .asciz "WARNING: WANT PMAPLOAD ON SYSCALL ENTRY\n"
1.1 fvdl 1301: #endif /* DIAGNOSTIC */
1.24 yamt 1302: 9: sti
1303: call _C_LABEL(pmap_load)
1.27 yamt 1304: jmp .Lsyscall_checkast /* re-check ASTs */
1.1 fvdl 1305:
1306: #if NNPX > 0
1307: /*
1308: * Special interrupt handlers. Someday intr0-intr15 will be used to count
1309: * interrupts. We'll still need a special exception 16 handler. The busy
1310: * latch stuff in probintr() can be moved to npxprobe().
1311: */
1312:
1313: /* LINTSTUB: Func: void probeintr(void) */
1314: NENTRY(probeintr)
1315: ss
1316: incl _C_LABEL(npx_intrs_while_probing)
1317: pushl %eax
1318: movb $0x20,%al # EOI (asm in strings loses cpp features)
1319: outb %al,$0xa0 # IO_ICU2
1320: outb %al,$0x20 # IO_ICU1
1321: movb $0,%al
1322: outb %al,$0xf0 # clear BUSY# latch
1323: popl %eax
1324: iret
1325:
1326: /* LINTSTUB: Func: void probetrap(void) */
1327: NENTRY(probetrap)
1328: ss
1329: incl _C_LABEL(npx_traps_while_probing)
1330: fnclex
1331: iret
1332:
1333: /* LINTSTUB: Func: int npx586bug1(int a, int b) */
1334: NENTRY(npx586bug1)
1335: fildl 4(%esp) # x
1336: fildl 8(%esp) # y
1337: fld %st(1)
1338: fdiv %st(1),%st # x/y
1339: fmulp %st,%st(1) # (x/y)*y
1340: fsubrp %st,%st(1) # x-(x/y)*y
1341: pushl $0
1342: fistpl (%esp)
1343: popl %eax
1344: ret
1345: #endif /* NNPX > 0 */
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