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Annotation of src/sys/arch/i386/i386/locore.S, Revision 1.3

1.3     ! gmcgarry    1: /*     $NetBSD: locore.S,v 1.2 2002/12/11 12:02:07 fvdl Exp $  */
1.1       fvdl        2:
                      3: /*-
                      4:  * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
                      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.
                     54:  * 3. All advertising materials mentioning features or use of this software
                     55:  *    must display the following acknowledgement:
                     56:  *     This product includes software developed by the University of
                     57:  *     California, Berkeley and its contributors.
                     58:  * 4. Neither the name of the University nor the names of its contributors
                     59:  *    may be used to endorse or promote products derived from this software
                     60:  *    without specific prior written permission.
                     61:  *
                     62:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     63:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     64:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     65:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     66:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     67:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     68:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     69:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     70:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     71:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     72:  * SUCH DAMAGE.
                     73:  *
                     74:  *     @(#)locore.s    7.3 (Berkeley) 5/13/91
                     75:  */
                     76:
                     77: #include "opt_cputype.h"
                     78: #include "opt_ddb.h"
                     79: #include "opt_ipkdb.h"
                     80: #include "opt_vm86.h"
                     81: #include "opt_user_ldt.h"
                     82: #include "opt_dummy_nops.h"
                     83: #include "opt_compat_oldboot.h"
                     84: #include "opt_multiprocessor.h"
                     85: #include "opt_lockdebug.h"
                     86: #include "opt_realmem.h"
                     87:
                     88: #include "npx.h"
                     89: #include "assym.h"
                     90: #include "apm.h"
                     91: #include "lapic.h"
                     92: #include "ioapic.h"
                     93:
                     94: #include <sys/errno.h>
                     95: #include <sys/syscall.h>
                     96:
                     97: #include <machine/cputypes.h>
                     98: #include <machine/param.h>
                     99: #include <machine/pte.h>
                    100: #include <machine/segments.h>
                    101: #include <machine/specialreg.h>
                    102: #include <machine/trap.h>
                    103: #include <machine/bootinfo.h>
                    104:
                    105: #if NLAPIC > 0
                    106: #include <machine/i82489reg.h>
                    107: #endif
                    108:
                    109: /* LINTSTUB: include <sys/types.h> */
                    110: /* LINTSTUB: include <machine/cpu.h> */
                    111: /* LINTSTUB: include <sys/systm.h> */
                    112:
                    113: #include <machine/asm.h>
                    114:
                    115: #if defined(MULTIPROCESSOR)
                    116:
                    117: #define SET_CURPROC(proc,cpu)                          \
                    118:        movl    CPUVAR(SELF),cpu                ;       \
                    119:        movl    proc,CPUVAR(CURPROC)    ;       \
                    120:        movl    cpu,P_CPU(proc)
                    121:
                    122: #else
                    123:
                    124: #define SET_CURPROC(proc,tcpu)         movl    proc,CPUVAR(CURPROC)
                    125: #define GET_CURPROC(reg)               movl    CPUVAR(CURPROC),reg
                    126:
                    127: #endif
                    128:
                    129: #define GET_CURPCB(reg)                        movl    CPUVAR(CURPCB),reg
                    130: #define SET_CURPCB(reg)                        movl    reg,CPUVAR(CURPCB)
                    131:
                    132: #define CLEAR_RESCHED(reg)             movl    reg,CPUVAR(RESCHED)
                    133:
                    134: /* XXX temporary kluge; these should not be here */
                    135: /* Get definitions for IOM_BEGIN, IOM_END, and IOM_SIZE */
                    136: #include <dev/isa/isareg.h>
                    137:
                    138:
                    139: /* Disallow old names for REALBASEMEM */
                    140: #ifdef BIOSBASEMEM
                    141: #error BIOSBASEMEM option deprecated; use REALBASEMEM only if memory size reported by latest boot block is incorrect
                    142: #endif
                    143:
                    144: /* Disallow old names for REALEXTMEM */
                    145: #ifdef EXTMEM_SIZE
                    146: #error EXTMEM_SIZE option deprecated; use REALEXTMEM only if memory size reported by latest boot block is incorrect
                    147: #endif
                    148: #ifdef BIOSEXTMEM
                    149: #error BIOSEXTMEM option deprecated; use REALEXTMEM only if memory size reported by latest boot block is incorrect
                    150: #endif
                    151:
                    152: #include <machine/frameasm.h>
                    153:
                    154:
                    155: #ifdef MULTIPROCESSOR
                    156: #include <machine/i82489reg.h>
                    157: #endif
                    158:
                    159: /*
                    160:  * PTmap is recursive pagemap at top of virtual address space.
                    161:  * Within PTmap, the page directory can be found (third indirection).
                    162:  *
                    163:  * XXX 4 == sizeof pde
                    164:  */
                    165:        .set    _C_LABEL(PTmap),(PDSLOT_PTE << PDSHIFT)
                    166:        .set    _C_LABEL(PTD),(_C_LABEL(PTmap) + PDSLOT_PTE * NBPG)
                    167:        .set    _C_LABEL(PTDpde),(_C_LABEL(PTD) + PDSLOT_PTE * 4)
                    168:
                    169: /*
                    170:  * APTmap, APTD is the alternate recursive pagemap.
                    171:  * It's used when modifying another process's page tables.
                    172:  *
                    173:  * XXX 4 == sizeof pde
                    174:  */
                    175:        .set    _C_LABEL(APTmap),(PDSLOT_APTE << PDSHIFT)
                    176:        .set    _C_LABEL(APTD),(_C_LABEL(APTmap) + PDSLOT_APTE * NBPG)
                    177:        .set    _C_LABEL(APTDpde),(_C_LABEL(PTD) + PDSLOT_APTE * 4)
                    178:
                    179:
                    180: /*
                    181:  * Initialization
                    182:  */
                    183:        .data
                    184:
                    185:        .globl  _C_LABEL(cpu)
                    186:        .globl  _C_LABEL(cpu_feature)
                    187:        .globl  _C_LABEL(esym),_C_LABEL(boothowto)
                    188:        .globl  _C_LABEL(bootinfo),_C_LABEL(atdevbase)
                    189: #ifdef COMPAT_OLDBOOT
                    190:        .globl  _C_LABEL(bootdev)
                    191: #endif
                    192:        .globl  _C_LABEL(proc0paddr),_C_LABEL(PTDpaddr)
                    193:        .globl  _C_LABEL(biosbasemem),_C_LABEL(biosextmem)
                    194:        .globl  _C_LABEL(gdt)
                    195: #ifdef I586_CPU
                    196:        .globl  _C_LABEL(idt)
                    197: #endif
                    198:        .globl  _C_LABEL(lapic_tpr)
                    199:
                    200: #if NLAPIC > 0
                    201: #ifdef __ELF__
                    202:        .align  NBPG
                    203: #else
                    204:        .align  12
                    205: #endif
                    206:        .globl _C_LABEL(local_apic), _C_LABEL(lapic_id)
                    207: _C_LABEL(local_apic):
                    208:        .space  LAPIC_ID
                    209: _C_LABEL(lapic_id):
                    210:        .long   0x00000000
                    211:        .space  LAPIC_TPRI-(LAPIC_ID+4)
                    212: _C_LABEL(lapic_tpr):
                    213:        .space  LAPIC_PPRI-LAPIC_TPRI
                    214: _C_LABEL(lapic_ppr):
                    215:        .space  LAPIC_ISR-LAPIC_PPRI
                    216: _C_LABEL(lapic_isr):
                    217:        .space  NBPG-LAPIC_ISR
                    218: #else
                    219: _C_LABEL(lapic_tpr):
                    220:        .long 0
                    221: #endif
                    222:
                    223:
                    224: _C_LABEL(cpu):         .long   0       # are we 386, 386sx, or 486,
                    225:                                        #   or Pentium, or..
                    226: _C_LABEL(cpu_feature): .long   0       # feature flags from 'cpuid'
                    227:                                        #   instruction
                    228: _C_LABEL(esym):                .long   0       # ptr to end of syms
                    229: _C_LABEL(atdevbase):   .long   0       # location of start of iomem in virtual
                    230: _C_LABEL(proc0paddr):  .long   0
                    231: _C_LABEL(PTDpaddr):    .long   0       # paddr of PTD, for libkvm
                    232: #ifndef REALBASEMEM
                    233: _C_LABEL(biosbasemem): .long   0       # base memory reported by BIOS
                    234: #else
                    235: _C_LABEL(biosbasemem): .long   REALBASEMEM
                    236: #endif
                    237: #ifndef REALEXTMEM
                    238: _C_LABEL(biosextmem):  .long   0       # extended memory reported by BIOS
                    239: #else
                    240: _C_LABEL(biosextmem):  .long   REALEXTMEM
                    241: #endif
                    242:
                    243:        .space 512
                    244: tmpstk:
                    245:
                    246:
                    247: #define        _RELOC(x)       ((x) - KERNBASE)
                    248: #define        RELOC(x)        _RELOC(_C_LABEL(x))
                    249:
                    250:        .text
                    251:        .globl  _C_LABEL(kernel_text)
                    252:        .set    _C_LABEL(kernel_text),KERNTEXTOFF
                    253:
                    254:        .globl  start
                    255: start: movw    $0x1234,0x472                   # warm boot
                    256:
                    257:        /*
                    258:         * Load parameters from stack
                    259:         * (howto, [bootdev], bootinfo, esym, basemem, extmem).
                    260:         */
                    261:        movl    4(%esp),%eax
                    262:        movl    %eax,RELOC(boothowto)
                    263: #ifdef COMPAT_OLDBOOT
                    264:        movl    8(%esp),%eax
                    265:        movl    %eax,RELOC(bootdev)
                    266: #endif
                    267:        movl    12(%esp),%eax
                    268:
                    269:        testl   %eax, %eax
                    270:        jz      1f
                    271:        movl    (%eax), %ebx            /* number of entries */
                    272:        movl    $RELOC(bootinfo), %edi
                    273:        movl    %ebx, (%edi)
                    274:        addl    $4, %edi
                    275: 2:
                    276:        testl   %ebx, %ebx
                    277:        jz      1f
                    278:        addl    $4, %eax
                    279:        movl    (%eax), %ecx            /* address of entry */
                    280:        pushl   %eax
                    281:        pushl   (%ecx)                  /* len */
                    282:        pushl   %ecx
                    283:        pushl   %edi
                    284:        addl    (%ecx), %edi            /* update dest pointer */
                    285:        cmpl    $_RELOC(_C_LABEL(bootinfo) + BOOTINFO_MAXSIZE), %edi
                    286:        jg      2f
                    287:        call    _C_LABEL(memcpy)
                    288:        addl    $12, %esp
                    289:        popl    %eax
                    290:        subl    $1, %ebx
                    291:        jmp     2b
                    292: 2:     /* cleanup for overflow case */
                    293:        addl    $16, %esp
                    294:        movl    $RELOC(bootinfo), %edi
                    295:        subl    %ebx, (%edi)            /* correct number of entries */
                    296: 1:
                    297:
                    298:        movl    16(%esp),%eax
                    299:        testl   %eax,%eax
                    300:        jz      1f
                    301:        addl    $KERNBASE,%eax
                    302: 1:     movl    %eax,RELOC(esym)
                    303:
                    304:        movl    RELOC(biosextmem),%eax
                    305:        testl   %eax,%eax
                    306:        jnz     1f
                    307:        movl    20(%esp),%eax
                    308:        movl    %eax,RELOC(biosextmem)
                    309: 1:
                    310:        movl    RELOC(biosbasemem),%eax
                    311:        testl   %eax,%eax
                    312:        jnz     1f
                    313:        movl    24(%esp),%eax
                    314:        movl    %eax,RELOC(biosbasemem)
                    315: 1:
                    316:
                    317:        /* First, reset the PSL. */
                    318:        pushl   $PSL_MBO
                    319:        popfl
                    320:
                    321:        /* Clear segment registers; always null in proc0. */
                    322:        xorl    %eax,%eax
                    323:        movw    %ax,%fs
                    324:        movw    %ax,%gs
                    325:        decl    %eax
                    326:        movl    %eax,RELOC(cpu_info_primary)+CPU_INFO_LEVEL
                    327:
                    328:        /* Find out our CPU type. */
                    329:
                    330: try386:        /* Try to toggle alignment check flag; does not exist on 386. */
                    331:        pushfl
                    332:        popl    %eax
                    333:        movl    %eax,%ecx
                    334:        orl     $PSL_AC,%eax
                    335:        pushl   %eax
                    336:        popfl
                    337:        pushfl
                    338:        popl    %eax
                    339:        xorl    %ecx,%eax
                    340:        andl    $PSL_AC,%eax
                    341:        pushl   %ecx
                    342:        popfl
                    343:
                    344:        testl   %eax,%eax
                    345:        jnz     try486
                    346:
                    347:        /*
                    348:         * Try the test of a NexGen CPU -- ZF will not change on a DIV
                    349:         * instruction on a NexGen, it will on an i386.  Documented in
                    350:         * Nx586 Processor Recognition Application Note, NexGen, Inc.
                    351:         */
                    352:        movl    $0x5555,%eax
                    353:        xorl    %edx,%edx
                    354:        movl    $2,%ecx
                    355:        divl    %ecx
                    356:        jnz     is386
                    357:
                    358: isnx586:
                    359:        /*
                    360:         * Don't try cpuid, as Nx586s reportedly don't support the
                    361:         * PSL_ID bit.
                    362:         */
                    363:        movl    $CPU_NX586,RELOC(cpu)
                    364:        jmp     2f
                    365:
                    366: is386:
                    367:        movl    $CPU_386,RELOC(cpu)
                    368:        jmp     2f
                    369:
                    370: try486:        /* Try to toggle identification flag; does not exist on early 486s. */
                    371:        pushfl
                    372:        popl    %eax
                    373:        movl    %eax,%ecx
                    374:        xorl    $PSL_ID,%eax
                    375:        pushl   %eax
                    376:        popfl
                    377:        pushfl
                    378:        popl    %eax
                    379:        xorl    %ecx,%eax
                    380:        andl    $PSL_ID,%eax
                    381:        pushl   %ecx
                    382:        popfl
                    383:
                    384:        testl   %eax,%eax
                    385:        jnz     try586
                    386: is486: movl    $CPU_486,RELOC(cpu)
                    387:        /*
                    388:         * Check Cyrix CPU
                    389:         * Cyrix CPUs do not change the undefined flags following
                    390:         * execution of the divide instruction which divides 5 by 2.
                    391:         *
                    392:         * Note: CPUID is enabled on M2, so it passes another way.
                    393:         */
                    394:        pushfl
                    395:        movl    $0x5555, %eax
                    396:        xorl    %edx, %edx
                    397:        movl    $2, %ecx
                    398:        clc
                    399:        divl    %ecx
                    400:        jnc     trycyrix486
                    401:        popfl
                    402:        jmp 2f
                    403: trycyrix486:
                    404:        movl    $CPU_6x86,RELOC(cpu)    # set CPU type
                    405:        /*
                    406:         * Check for Cyrix 486 CPU by seeing if the flags change during a
                    407:         * divide. This is documented in the Cx486SLC/e SMM Programmer's
                    408:         * Guide.
                    409:         */
                    410:        xorl    %edx,%edx
                    411:        cmpl    %edx,%edx               # set flags to known state
                    412:        pushfl
                    413:        popl    %ecx                    # store flags in ecx
                    414:        movl    $-1,%eax
                    415:        movl    $4,%ebx
                    416:        divl    %ebx                    # do a long division
                    417:        pushfl
                    418:        popl    %eax
                    419:        xorl    %ecx,%eax               # are the flags different?
                    420:        testl   $0x8d5,%eax             # only check C|PF|AF|Z|N|V
                    421:        jne     2f                      # yes; must be Cyrix 6x86 CPU
                    422:        movl    $CPU_486DLC,RELOC(cpu)  # set CPU type
                    423:
                    424: #ifndef CYRIX_CACHE_WORKS
                    425:        /* Disable caching of the ISA hole only. */
                    426:        invd
                    427:        movb    $CCR0,%al               # Configuration Register index (CCR0)
                    428:        outb    %al,$0x22
                    429:        inb     $0x23,%al
                    430:        orb     $(CCR0_NC1|CCR0_BARB),%al
                    431:        movb    %al,%ah
                    432:        movb    $CCR0,%al
                    433:        outb    %al,$0x22
                    434:        movb    %ah,%al
                    435:        outb    %al,$0x23
                    436:        invd
                    437: #else /* CYRIX_CACHE_WORKS */
                    438:        /* Set cache parameters */
                    439:        invd                            # Start with guaranteed clean cache
                    440:        movb    $CCR0,%al               # Configuration Register index (CCR0)
                    441:        outb    %al,$0x22
                    442:        inb     $0x23,%al
                    443:        andb    $~CCR0_NC0,%al
                    444: #ifndef CYRIX_CACHE_REALLY_WORKS
                    445:        orb     $(CCR0_NC1|CCR0_BARB),%al
                    446: #else
                    447:        orb     $CCR0_NC1,%al
                    448: #endif
                    449:        movb    %al,%ah
                    450:        movb    $CCR0,%al
                    451:        outb    %al,$0x22
                    452:        movb    %ah,%al
                    453:        outb    %al,$0x23
                    454:        /* clear non-cacheable region 1 */
                    455:        movb    $(NCR1+2),%al
                    456:        outb    %al,$0x22
                    457:        movb    $NCR_SIZE_0K,%al
                    458:        outb    %al,$0x23
                    459:        /* clear non-cacheable region 2 */
                    460:        movb    $(NCR2+2),%al
                    461:        outb    %al,$0x22
                    462:        movb    $NCR_SIZE_0K,%al
                    463:        outb    %al,$0x23
                    464:        /* clear non-cacheable region 3 */
                    465:        movb    $(NCR3+2),%al
                    466:        outb    %al,$0x22
                    467:        movb    $NCR_SIZE_0K,%al
                    468:        outb    %al,$0x23
                    469:        /* clear non-cacheable region 4 */
                    470:        movb    $(NCR4+2),%al
                    471:        outb    %al,$0x22
                    472:        movb    $NCR_SIZE_0K,%al
                    473:        outb    %al,$0x23
                    474:        /* enable caching in CR0 */
                    475:        movl    %cr0,%eax
                    476:        andl    $~(CR0_CD|CR0_NW),%eax
                    477:        movl    %eax,%cr0
                    478:        invd
                    479: #endif /* CYRIX_CACHE_WORKS */
                    480:
                    481:        jmp     2f
                    482:
                    483: try586:        /* Use the `cpuid' instruction. */
                    484:        xorl    %eax,%eax
                    485:        cpuid
                    486:        movl    %eax,RELOC(cpu_info_primary)+CPU_INFO_LEVEL
                    487:
                    488: 2:
                    489:        /*
                    490:         * Finished with old stack; load new %esp now instead of later so we
                    491:         * can trace this code without having to worry about the trace trap
                    492:         * clobbering the memory test or the zeroing of the bss+bootstrap page
                    493:         * tables.
                    494:         *
                    495:         * The boot program should check:
                    496:         *      text+data <= &stack_variable - more_space_for_stack
                    497:         *      text+data+bss+pad+space_for_page_tables <= end_of_memory
                    498:         * Oops, the gdt is in the carcass of the boot program so clearing
                    499:         * the rest of memory is still not possible.
                    500:         */
                    501:        movl    $_RELOC(tmpstk),%esp    # bootstrap stack end location
                    502:
                    503: /*
                    504:  * Virtual address space of kernel:
                    505:  *
                    506:  * text | data | bss | [syms] | page dir | proc0 kstack
                    507:  *                           0          1       2      3
                    508:  */
                    509: #define        PROC0PDIR       ((0)              * NBPG)
                    510: #define        PROC0STACK      ((1)              * NBPG)
                    511: #define        SYSMAP          ((1+UPAGES)       * NBPG)
                    512: #define        TABLESIZE       ((1+UPAGES) * NBPG) /* + nkpde * NBPG */
                    513:
                    514:        /* Find end of kernel image. */
                    515:        movl    $RELOC(end),%edi
                    516: #if defined(DDB) && !defined(SYMTAB_SPACE)
                    517:        /* Save the symbols (if loaded). */
                    518:        movl    RELOC(esym),%eax
                    519:        testl   %eax,%eax
                    520:        jz      1f
                    521:        subl    $KERNBASE,%eax
                    522:        movl    %eax,%edi
                    523: 1:
                    524: #endif
                    525:
                    526:        /* Calculate where to start the bootstrap tables. */
                    527:        movl    %edi,%esi                       # edi = esym ? esym : end
                    528:        addl    $PGOFSET,%esi                   # page align up
                    529:        andl    $~PGOFSET,%esi
                    530:
                    531:        /*
                    532:         * Calculate the size of the kernel page table directory, and
                    533:         * how many entries it will have.
                    534:         */
                    535:        movl    RELOC(nkpde),%ecx               # get nkpde
                    536:        cmpl    $NKPTP_MIN,%ecx                 # larger than min?
                    537:        jge     1f
                    538:        movl    $NKPTP_MIN,%ecx                 # set at min
                    539:        jmp     2f
                    540: 1:     cmpl    $NKPTP_MAX,%ecx                 # larger than max?
                    541:        jle     2f
                    542:        movl    $NKPTP_MAX,%ecx
                    543: 2:
                    544:
                    545:        /* Clear memory for bootstrap tables. */
                    546:        shll    $PGSHIFT,%ecx
                    547:        addl    $TABLESIZE,%ecx
                    548:        addl    %esi,%ecx                       # end of tables
                    549:        subl    %edi,%ecx                       # size of tables
                    550:        shrl    $2,%ecx
                    551:        xorl    %eax,%eax
                    552:        cld
                    553:        rep
                    554:        stosl
                    555:
                    556: /*
                    557:  * fillkpt
                    558:  *     eax = pte (page frame | control | status)
                    559:  *     ebx = page table address
                    560:  *     ecx = number of pages to map
                    561:  */
                    562: #define        fillkpt         \
                    563: 1:     movl    %eax,(%ebx)     ; \
                    564:        addl    $NBPG,%eax      ; /* increment physical address */ \
                    565:        addl    $4,%ebx         ; /* next pte */ \
                    566:        loop    1b              ;
                    567:
                    568: /*
                    569:  * Build initial page tables.
                    570:  */
                    571:        /* Calculate end of text segment, rounded to a page. */
                    572:        leal    (RELOC(etext)+PGOFSET),%edx
                    573:        andl    $~PGOFSET,%edx
                    574:
                    575:        /* Skip over the first 1MB. */
                    576:        movl    $_RELOC(KERNTEXTOFF),%eax
                    577:        movl    %eax,%ecx
                    578:        shrl    $PGSHIFT,%ecx
                    579:        leal    (SYSMAP)(%esi,%ecx,4),%ebx
                    580:
                    581:        /* Map the kernel text read-only. */
                    582:        movl    %edx,%ecx
                    583:        subl    %eax,%ecx
                    584:        shrl    $PGSHIFT,%ecx
                    585:        orl     $(PG_V|PG_KR),%eax
                    586:        fillkpt
                    587:
                    588:        /* Map the data, BSS, and bootstrap tables read-write. */
                    589:        leal    (PG_V|PG_KW)(%edx),%eax
                    590:        movl    RELOC(nkpde),%ecx
                    591:        shll    $PGSHIFT,%ecx
                    592:        addl    $TABLESIZE,%ecx
                    593:        addl    %esi,%ecx                               # end of tables
                    594:        subl    %edx,%ecx                               # subtract end of text
                    595:        shrl    $PGSHIFT,%ecx
                    596:        fillkpt
                    597:
                    598:        /* Map ISA I/O memory. */
                    599:        movl    $(IOM_BEGIN|PG_V|PG_KW/*|PG_N*/),%eax   # having these bits set
                    600:        movl    $(IOM_SIZE>>PGSHIFT),%ecx               # for this many pte s,
                    601:        fillkpt
                    602:
                    603: /*
                    604:  * Construct a page table directory.
                    605:  */
                    606:        /* Install PDEs for temporary double map of kernel. */
                    607:        movl    RELOC(nkpde),%ecx                       # for this many pde s,
                    608:        leal    (PROC0PDIR+0*4)(%esi),%ebx              # which is where temp maps!
                    609:        leal    (SYSMAP+PG_V|PG_KW)(%esi),%eax          # pte for KPT in proc 0,
                    610:        fillkpt
                    611:
                    612:        /* Map kernel PDEs. */
                    613:        movl    RELOC(nkpde),%ecx                       # for this many pde s,
                    614:        leal    (PROC0PDIR+PDSLOT_KERN*4)(%esi),%ebx    # kernel pde offset
                    615:        leal    (SYSMAP+PG_V|PG_KW)(%esi),%eax          # pte for KPT in proc 0,
                    616:        fillkpt
                    617:
                    618:        /* Install a PDE recursively mapping page directory as a page table! */
                    619:        leal    (PROC0PDIR+PG_V|PG_KW)(%esi),%eax       # pte for ptd
                    620:        movl    %eax,(PROC0PDIR+PDSLOT_PTE*4)(%esi)     # recursive PD slot
                    621:
                    622:        /* Save phys. addr of PTD, for libkvm. */
                    623:        movl    %esi,RELOC(PTDpaddr)
                    624:
                    625:        /* Load base of page directory and enable mapping. */
                    626:        movl    %esi,%eax               # phys address of ptd in proc 0
                    627:        movl    %eax,%cr3               # load ptd addr into mmu
                    628:        movl    %cr0,%eax               # get control word
                    629:                                        # enable paging & NPX emulation
                    630:        orl     $(CR0_PE|CR0_PG|CR0_NE|CR0_TS|CR0_EM|CR0_MP),%eax
                    631:        movl    %eax,%cr0               # and let's page NOW!
                    632:
                    633:        pushl   $begin                  # jump to high mem
                    634:        ret
                    635:
                    636: begin:
                    637:        /* Now running relocated at KERNBASE.  Remove double mapping. */
                    638:        movl    _C_LABEL(nkpde),%ecx            # for this many pde s,
                    639:        leal    (PROC0PDIR+0*4)(%esi),%ebx      # which is where temp maps!
                    640:        addl    $(KERNBASE), %ebx       # now use relocated address
                    641: 1:     movl    $0,(%ebx)
                    642:        addl    $4,%ebx # next pde
                    643:        loop    1b
                    644:
                    645:        /* Relocate atdevbase. */
                    646:        movl    _C_LABEL(nkpde),%edx
                    647:        shll    $PGSHIFT,%edx
                    648:        addl    $(TABLESIZE+KERNBASE),%edx
                    649:        addl    %esi,%edx
                    650:        movl    %edx,_C_LABEL(atdevbase)
                    651:
                    652:        /* Set up bootstrap stack. */
                    653:        leal    (PROC0STACK+KERNBASE)(%esi),%eax
                    654:        movl    %eax,_C_LABEL(proc0paddr)
                    655:        leal    (USPACE-FRAMESIZE)(%eax),%esp
                    656:        movl    %esi,PCB_CR3(%eax)      # pcb->pcb_cr3
                    657:        xorl    %ebp,%ebp               # mark end of frames
                    658:
                    659:        subl    $NGDT*8, %esp           # space for temporary gdt
                    660:        pushl   %esp
                    661:        call    _C_LABEL(initgdt)
                    662:        addl    $4,%esp
                    663:
                    664:        movl    _C_LABEL(nkpde),%eax
                    665:        shll    $PGSHIFT,%eax
                    666:        addl    $TABLESIZE,%eax
                    667:        addl    %esi,%eax               # skip past stack and page tables
                    668:
                    669:        pushl   %eax
                    670:        call    _C_LABEL(init386)       # wire 386 chip for unix operation
                    671:        addl    $4+NGDT*8,%esp          # pop temporary gdt
                    672:
                    673: #ifdef SAFARI_FIFO_HACK
                    674:        movb    $5,%al
                    675:        movw    $0x37b,%dx
                    676:        outb    %al,%dx
                    677:        movw    $0x37f,%dx
                    678:        inb     %dx,%al
                    679:        movb    %al,%cl
                    680:
                    681:        orb     $1,%cl
                    682:
                    683:        movb    $5,%al
                    684:        movw    $0x37b,%dx
                    685:        outb    %al,%dx
                    686:        movw    $0x37f,%dx
                    687:        movb    %cl,%al
                    688:        outb    %al,%dx
                    689: #endif /* SAFARI_FIFO_HACK */
                    690:
                    691:        call    _C_LABEL(main)
                    692:
                    693: /*
                    694:  * void proc_trampoline(void);
                    695:  * This is a trampoline function pushed onto the stack of a newly created
                    696:  * process in order to do some additional setup.  The trampoline is entered by
                    697:  * cpu_switch()ing to the process, so we abuse the callee-saved registers used
                    698:  * by cpu_switch() to store the information about the stub to call.
                    699:  * NOTE: This function does not have a normal calling sequence!
                    700:  */
                    701: /* LINTSTUB: Func: void proc_trampoline(void) */
                    702: NENTRY(proc_trampoline)
                    703: #ifdef MULTIPROCESSOR
                    704:        call    _C_LABEL(proc_trampoline_mp)
                    705: #endif
                    706:        movl    $IPL_NONE,CPUVAR(ILEVEL)
                    707:        pushl   %ebx
                    708:        call    *%esi
                    709:        addl    $4,%esp
                    710:        INTRFASTEXIT
                    711:        /* NOTREACHED */
                    712:
                    713: /*****************************************************************************/
                    714:
                    715: /*
                    716:  * Signal trampoline; copied to top of user stack.
                    717:  */
                    718: /* LINTSTUB: Var: char sigcode[1], esigcode[1]; */
                    719: NENTRY(sigcode)
                    720:        /*
                    721:         * Handler has returned here as if we called it.  The sigcontext
                    722:         * is on the stack after the 3 args "we" pushed.
                    723:         */
                    724:        leal    12(%esp),%eax           # get pointer to sigcontext
                    725:        movl    %eax,4(%esp)            # put it in the argument slot
                    726:                                        # fake return address already there
                    727:        movl    $SYS___sigreturn14,%eax
                    728:        int     $0x80                   # enter kernel with args on stack
                    729:        movl    $SYS_exit,%eax
                    730:        int     $0x80                   # exit if sigreturn fails
                    731:        .globl  _C_LABEL(esigcode)
                    732: _C_LABEL(esigcode):
                    733:
                    734: /*****************************************************************************/
                    735:
                    736: /*
                    737:  * The following primitives are used to fill and copy regions of memory.
                    738:  */
                    739:
                    740: /*
                    741:  * XXX No section 9 man page for fillw.
                    742:  * fillw seems to be very sparsely used (only in pccons it seems.)
                    743:  * One wonders if it couldn't be done without.
                    744:  * -- Perry Metzger, May 7, 2001
                    745:  */
                    746: /*
                    747:  * void fillw(short pattern, void *addr, size_t len);
                    748:  * Write len copies of pattern at addr.
                    749:  */
                    750: /* LINTSTUB: Func: void fillw(short pattern, void *addr, size_t len) */
                    751: ENTRY(fillw)
                    752:        pushl   %edi
                    753:        movl    8(%esp),%eax
                    754:        movl    12(%esp),%edi
                    755:        movw    %ax,%cx
                    756:        rorl    $16,%eax
                    757:        movw    %cx,%ax
                    758:        cld
                    759:        movl    16(%esp),%ecx
                    760:        shrl    %ecx                    # do longwords
                    761:        rep
                    762:        stosl
                    763:        movl    16(%esp),%ecx
                    764:        andl    $1,%ecx                 # do remainder
                    765:        rep
                    766:        stosw
                    767:        popl    %edi
                    768:        ret
                    769:
                    770: /*
                    771:  * int kcopy(const void *from, void *to, size_t len);
                    772:  * Copy len bytes, abort on fault.
                    773:  */
                    774: /* LINTSTUB: Func: int kcopy(const void *from, void *to, size_t len) */
                    775: ENTRY(kcopy)
                    776:        pushl   %esi
                    777:        pushl   %edi
                    778:        GET_CURPCB(%eax)                # load curpcb into eax and set on-fault
                    779:        pushl   PCB_ONFAULT(%eax)
                    780:        movl    $_C_LABEL(copy_fault), PCB_ONFAULT(%eax)
                    781:
                    782:        movl    16(%esp),%esi
                    783:        movl    20(%esp),%edi
                    784:        movl    24(%esp),%ecx
                    785:        movl    %edi,%eax
                    786:        subl    %esi,%eax
                    787:        cmpl    %ecx,%eax               # overlapping?
                    788:        jb      1f
                    789:        cld                             # nope, copy forward
                    790:        shrl    $2,%ecx                 # copy by 32-bit words
                    791:        rep
                    792:        movsl
                    793:        movl    24(%esp),%ecx
                    794:        andl    $3,%ecx                 # any bytes left?
                    795:        rep
                    796:        movsb
                    797:
                    798:        GET_CURPCB(%edx)                # XXX save curpcb?
                    799:        popl    PCB_ONFAULT(%edx)
                    800:        popl    %edi
                    801:        popl    %esi
                    802:        xorl    %eax,%eax
                    803:        ret
                    804:
                    805:        ALIGN_TEXT
                    806: 1:     addl    %ecx,%edi               # copy backward
                    807:        addl    %ecx,%esi
                    808:        std
                    809:        andl    $3,%ecx                 # any fractional bytes?
                    810:        decl    %edi
                    811:        decl    %esi
                    812:        rep
                    813:        movsb
                    814:        movl    24(%esp),%ecx           # copy remainder by 32-bit words
                    815:        shrl    $2,%ecx
                    816:        subl    $3,%esi
                    817:        subl    $3,%edi
                    818:        rep
                    819:        movsl
                    820:        cld
                    821:
                    822:        GET_CURPCB(%edx)
                    823:        popl    PCB_ONFAULT(%edx)
                    824:        popl    %edi
                    825:        popl    %esi
                    826:        xorl    %eax,%eax
                    827:        ret
                    828:
                    829: /*****************************************************************************/
                    830:
                    831: /*
                    832:  * The following primitives are used to copy data in and out of the user's
                    833:  * address space.
                    834:  */
                    835:
                    836: /*
                    837:  * Default to the lowest-common-denominator.  We will improve it
                    838:  * later.
                    839:  */
                    840: #if defined(I386_CPU)
                    841: #define        DEFAULT_COPYOUT         _C_LABEL(i386_copyout)
                    842: #define        DEFAULT_COPYIN          _C_LABEL(i386_copyin)
                    843: #elif defined(I486_CPU)
                    844: #define        DEFAULT_COPYOUT         _C_LABEL(i486_copyout)
                    845: #define        DEFAULT_COPYIN          _C_LABEL(i386_copyin)
                    846: #elif defined(I586_CPU)
                    847: #define        DEFAULT_COPYOUT         _C_LABEL(i486_copyout)  /* XXX */
                    848: #define        DEFAULT_COPYIN          _C_LABEL(i386_copyin)   /* XXX */
                    849: #elif defined(I686_CPU)
                    850: #define        DEFAULT_COPYOUT         _C_LABEL(i486_copyout)  /* XXX */
                    851: #define        DEFAULT_COPYIN          _C_LABEL(i386_copyin)   /* XXX */
                    852: #endif
                    853:
                    854:        .data
                    855:
                    856:        .globl  _C_LABEL(copyout_func)
                    857: _C_LABEL(copyout_func):
                    858:        .long   DEFAULT_COPYOUT
                    859:
                    860:        .globl  _C_LABEL(copyin_func)
                    861: _C_LABEL(copyin_func):
                    862:        .long   DEFAULT_COPYIN
                    863:
                    864:        .text
                    865:
                    866: /*
                    867:  * int copyout(const void *from, void *to, size_t len);
                    868:  * Copy len bytes into the user's address space.
                    869:  * see copyout(9)
                    870:  */
                    871: /* LINTSTUB: Func: int copyout(const void *kaddr, void *uaddr, size_t len) */
                    872: ENTRY(copyout)
                    873:        jmp     *_C_LABEL(copyout_func)
                    874:
                    875: #if defined(I386_CPU)
                    876: /* LINTSTUB: Func: int i386_copyout(const void *kaddr, void *uaddr, size_t len) */
                    877: ENTRY(i386_copyout)
                    878:        pushl   %esi
                    879:        pushl   %edi
                    880:        pushl   $0
                    881:
                    882:        movl    16(%esp),%esi
                    883:        movl    20(%esp),%edi
                    884:        movl    24(%esp),%eax
                    885:
                    886:        /*
                    887:         * We check that the end of the destination buffer is not past the end
                    888:         * of the user's address space.  If it's not, then we only need to
                    889:         * check that each page is writable.  The 486 will do this for us; the
                    890:         * 386 will not.  (We assume that pages in user space that are not
                    891:         * writable by the user are not writable by the kernel either.)
                    892:         */
                    893:        movl    %edi,%edx
                    894:        addl    %eax,%edx
                    895:        jc      _C_LABEL(copy_efault)
                    896:        cmpl    $VM_MAXUSER_ADDRESS,%edx
                    897:        ja      _C_LABEL(copy_efault)
                    898:
                    899:        testl   %eax,%eax               # anything to do?
                    900:        jz      3f
                    901:
                    902:        /*
                    903:         * We have to check each PTE for (write) permission, since the CPU
                    904:         * doesn't do it for us.
                    905:         */
                    906:
                    907:        /* Compute number of pages. */
                    908:        movl    %edi,%ecx
                    909:        andl    $PGOFSET,%ecx
                    910:        addl    %eax,%ecx
                    911:        decl    %ecx
                    912:        shrl    $PGSHIFT,%ecx
                    913:
                    914:        /* Compute PTE offset for start address. */
                    915:        shrl    $PGSHIFT,%edi
                    916:
                    917:        GET_CURPCB(%edx)
                    918:        movl    $2f,PCB_ONFAULT(%edx)
                    919:
                    920: 1:     /* Check PTE for each page. */
                    921:        testb   $PG_RW,_C_LABEL(PTmap)(,%edi,4)
                    922:        jz      2f
                    923:
                    924: 4:     incl    %edi
                    925:        decl    %ecx
                    926:        jns     1b
                    927:
                    928:        movl    20(%esp),%edi
                    929:        movl    24(%esp),%eax
                    930:        jmp     3f
                    931:
                    932: 2:     /* Simulate a trap. */
                    933:        pushl   %ecx
                    934:        movl    %edi,%eax
                    935:        shll    $PGSHIFT,%eax
                    936:        pushl   %eax
                    937:        call    _C_LABEL(trapwrite)     # trapwrite(addr)
                    938:        addl    $4,%esp                 # pop argument
                    939:        popl    %ecx
                    940:        testl   %eax,%eax               # if not ok, return EFAULT
                    941:        jz      4b
                    942:        jmp     _C_LABEL(copy_efault)
                    943:
                    944: 3:     GET_CURPCB(%edx)
                    945:        movl    $_C_LABEL(copy_fault),PCB_ONFAULT(%edx)
                    946:
                    947:        /* bcopy(%esi, %edi, %eax); */
                    948:        cld
                    949:        movl    %eax,%ecx
                    950:        shrl    $2,%ecx
                    951:        rep
                    952:        movsl
                    953:        movl    %eax,%ecx
                    954:        andl    $3,%ecx
                    955:        rep
                    956:        movsb
                    957:
                    958:        popl    PCB_ONFAULT(%edx)
                    959:        popl    %edi
                    960:        popl    %esi
                    961:        xorl    %eax,%eax
                    962:        ret
                    963: #endif /* I386_CPU */
                    964:
                    965: #if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)
                    966: /* LINTSTUB: Func: int i486_copyout(const void *kaddr, void *uaddr, size_t len) */
                    967: ENTRY(i486_copyout)
                    968:        pushl   %esi
                    969:        pushl   %edi
                    970:        pushl   $0
                    971:
                    972:        movl    16(%esp),%esi
                    973:        movl    20(%esp),%edi
                    974:        movl    24(%esp),%eax
                    975:
                    976:        /*
                    977:         * We check that the end of the destination buffer is not past the end
                    978:         * of the user's address space.
                    979:         */
                    980:        movl    %edi,%edx
                    981:        addl    %eax,%edx
                    982:        jc      _C_LABEL(copy_efault)
                    983:        cmpl    $VM_MAXUSER_ADDRESS,%edx
                    984:        ja      _C_LABEL(copy_efault)
                    985:
                    986:        GET_CURPCB(%edx)
                    987:        movl    $_C_LABEL(copy_fault),PCB_ONFAULT(%edx)
                    988:
                    989:        /* bcopy(%esi, %edi, %eax); */
                    990:        cld
                    991:        movl    %eax,%ecx
                    992:        shrl    $2,%ecx
                    993:        rep
                    994:        movsl
                    995:        movl    %eax,%ecx
                    996:        andl    $3,%ecx
                    997:        rep
                    998:        movsb
                    999:
                   1000:        popl    PCB_ONFAULT(%edx)
                   1001:        popl    %edi
                   1002:        popl    %esi
                   1003:        xorl    %eax,%eax
                   1004:        ret
                   1005: #endif /* I486_CPU || I586_CPU || I686_CPU */
                   1006:
                   1007: /*
                   1008:  * int copyin(const void *from, void *to, size_t len);
                   1009:  * Copy len bytes from the user's address space.
                   1010:  * see copyin(9)
                   1011:  */
                   1012: /* LINTSTUB: Func: int copyin(const void *uaddr, void *kaddr, size_t len) */
                   1013: ENTRY(copyin)
                   1014:        jmp     *_C_LABEL(copyin_func)
                   1015:
                   1016: #if defined(I386_CPU) || defined(I486_CPU) || defined(I586_CPU) || \
                   1017:     defined(I686_CPU)
                   1018: /* LINTSTUB: Func: int i386_copyin(const void *uaddr, void *kaddr, size_t len) */
                   1019: ENTRY(i386_copyin)
                   1020:        pushl   %esi
                   1021:        pushl   %edi
                   1022:        GET_CURPCB(%eax)
                   1023:        pushl   $0
                   1024:        movl    $_C_LABEL(copy_fault),PCB_ONFAULT(%eax)
                   1025:
                   1026:        movl    16(%esp),%esi
                   1027:        movl    20(%esp),%edi
                   1028:        movl    24(%esp),%eax
                   1029:
                   1030:        /*
                   1031:         * We check that the end of the destination buffer is not past the end
                   1032:         * of the user's address space.  If it's not, then we only need to
                   1033:         * check that each page is readable, and the CPU will do that for us.
                   1034:         */
                   1035:        movl    %esi,%edx
                   1036:        addl    %eax,%edx
                   1037:        jc      _C_LABEL(copy_efault)
                   1038:        cmpl    $VM_MAXUSER_ADDRESS,%edx
                   1039:        ja      _C_LABEL(copy_efault)
                   1040:
                   1041:        /* bcopy(%esi, %edi, %eax); */
                   1042:        cld
                   1043:        movl    %eax,%ecx
                   1044:        shrl    $2,%ecx
                   1045:        rep
                   1046:        movsl
                   1047:        movl    %eax,%ecx
                   1048:        andl    $3,%ecx
                   1049:        rep
                   1050:        movsb
                   1051:
                   1052:        GET_CURPCB(%edx)
                   1053:        popl    PCB_ONFAULT(%edx)
                   1054:        popl    %edi
                   1055:        popl    %esi
                   1056:        xorl    %eax,%eax
                   1057:        ret
                   1058: #endif /* I386_CPU || I486_CPU || I586_CPU || I686_CPU */
                   1059:
                   1060: /* LINTSTUB: Ignore */
                   1061: NENTRY(copy_efault)
                   1062:        movl    $EFAULT,%eax
                   1063:
                   1064: /* LINTSTUB: Ignore */
                   1065: NENTRY(copy_fault)
                   1066:        GET_CURPCB(%edx)
                   1067:        popl    PCB_ONFAULT(%edx)
                   1068:        popl    %edi
                   1069:        popl    %esi
                   1070:        ret
                   1071:
                   1072: /*
                   1073:  * int copyoutstr(const void *from, void *to, size_t maxlen, size_t *lencopied);
                   1074:  * Copy a NUL-terminated string, at most maxlen characters long, into the
                   1075:  * user's address space.  Return the number of characters copied (including the
                   1076:  * NUL) in *lencopied.  If the string is too long, return ENAMETOOLONG; else
                   1077:  * return 0 or EFAULT.
                   1078:  * see copyoutstr(9)
                   1079:  */
                   1080: /* LINTSTUB: Func: int copyoutstr(const void *kaddr, void *uaddr, size_t len, size_t *done) */
                   1081: ENTRY(copyoutstr)
                   1082:        pushl   %esi
                   1083:        pushl   %edi
                   1084:
                   1085:        movl    12(%esp),%esi           # esi = from
                   1086:        movl    16(%esp),%edi           # edi = to
                   1087:        movl    20(%esp),%edx           # edx = maxlen
                   1088:
                   1089: #if defined(I386_CPU)
                   1090: #if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)
                   1091:        cmpl    $CPUCLASS_386,_C_LABEL(cpu_class)
                   1092:        jne     5f
                   1093: #endif /* I486_CPU || I586_CPU || I686_CPU */
                   1094:
                   1095:        /* Compute number of bytes in first page. */
                   1096:        movl    %edi,%eax
                   1097:        andl    $PGOFSET,%eax
                   1098:        movl    $NBPG,%ecx
                   1099:        subl    %eax,%ecx               # ecx = NBPG - (src % NBPG)
                   1100:
                   1101:        GET_CURPCB(%eax)
                   1102:        movl    $6f,PCB_ONFAULT(%eax)
                   1103:
                   1104: 1:     /*
                   1105:         * Once per page, check that we are still within the bounds of user
                   1106:         * space, and check for a write fault.
                   1107:         */
                   1108:        cmpl    $VM_MAXUSER_ADDRESS,%edi
                   1109:        jae     _C_LABEL(copystr_efault)
                   1110:
                   1111:        /* Compute PTE offset. */
                   1112:        movl    %edi,%eax
                   1113:        shrl    $PGSHIFT,%eax           # calculate pte address
                   1114:
                   1115:        testb   $PG_RW,_C_LABEL(PTmap)(,%eax,4)
                   1116:        jnz     2f
                   1117:
                   1118: 6:     /* Simulate a trap. */
                   1119:        pushl   %edx
                   1120:        pushl   %edi
                   1121:        call    _C_LABEL(trapwrite)     # trapwrite(addr)
                   1122:        addl    $4,%esp                 # clear argument from stack
                   1123:        popl    %edx
                   1124:        testl   %eax,%eax
                   1125:        jnz     _C_LABEL(copystr_efault)
                   1126:
                   1127: 2:     /* Copy up to end of this page. */
                   1128:        subl    %ecx,%edx               # predecrement total count
                   1129:        jnc     3f
                   1130:        addl    %edx,%ecx               # ecx += (edx - ecx) = edx
                   1131:        xorl    %edx,%edx
                   1132:
                   1133: 3:     decl    %ecx
                   1134:        js      4f
                   1135:        lodsb
                   1136:        stosb
                   1137:        testb   %al,%al
                   1138:        jnz     3b
                   1139:
                   1140:        /* Success -- 0 byte reached. */
                   1141:        addl    %ecx,%edx               # add back residual for this page
                   1142:        xorl    %eax,%eax
                   1143:        jmp     copystr_return
                   1144:
                   1145: 4:     /* Go to next page, if any. */
                   1146:        movl    $NBPG,%ecx
                   1147:        testl   %edx,%edx
                   1148:        jnz     1b
                   1149:
                   1150:        /* edx is zero -- return ENAMETOOLONG. */
                   1151:        movl    $ENAMETOOLONG,%eax
                   1152:        jmp     copystr_return
                   1153: #endif /* I386_CPU */
                   1154:
                   1155: #if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)
                   1156: 5:     GET_CURPCB(%eax)
                   1157:        movl    $_C_LABEL(copystr_fault),PCB_ONFAULT(%eax)
                   1158:        /*
                   1159:         * Get min(%edx, VM_MAXUSER_ADDRESS-%edi).
                   1160:         */
                   1161:        movl    $VM_MAXUSER_ADDRESS,%eax
                   1162:        subl    %edi,%eax
                   1163:        cmpl    %edx,%eax
                   1164:        jae     1f
                   1165:        movl    %eax,%edx
                   1166:        movl    %eax,20(%esp)
                   1167:
                   1168: 1:     incl    %edx
                   1169:        cld
                   1170:
                   1171: 1:     decl    %edx
                   1172:        jz      2f
                   1173:        lodsb
                   1174:        stosb
                   1175:        testb   %al,%al
                   1176:        jnz     1b
                   1177:
                   1178:        /* Success -- 0 byte reached. */
                   1179:        decl    %edx
                   1180:        xorl    %eax,%eax
                   1181:        jmp     copystr_return
                   1182:
                   1183: 2:     /* edx is zero -- return EFAULT or ENAMETOOLONG. */
                   1184:        cmpl    $VM_MAXUSER_ADDRESS,%edi
                   1185:        jae     _C_LABEL(copystr_efault)
                   1186:        movl    $ENAMETOOLONG,%eax
                   1187:        jmp     copystr_return
                   1188: #endif /* I486_CPU || I586_CPU || I686_CPU */
                   1189:
                   1190: /*
                   1191:  * int copyinstr(const void *from, void *to, size_t maxlen, size_t *lencopied);
                   1192:  * Copy a NUL-terminated string, at most maxlen characters long, from the
                   1193:  * user's address space.  Return the number of characters copied (including the
                   1194:  * NUL) in *lencopied.  If the string is too long, return ENAMETOOLONG; else
                   1195:  * return 0 or EFAULT.
                   1196:  * see copyinstr(9)
                   1197:  */
                   1198: /* LINTSTUB: Func: int copyinstr(const void *uaddr, void *kaddr, size_t len, size_t *done) */
                   1199: ENTRY(copyinstr)
                   1200:        pushl   %esi
                   1201:        pushl   %edi
                   1202:        GET_CURPCB(%ecx)
                   1203:        movl    $_C_LABEL(copystr_fault),PCB_ONFAULT(%ecx)
                   1204:
                   1205:        movl    12(%esp),%esi           # %esi = from
                   1206:        movl    16(%esp),%edi           # %edi = to
                   1207:        movl    20(%esp),%edx           # %edx = maxlen
                   1208:
                   1209:        /*
                   1210:         * Get min(%edx, VM_MAXUSER_ADDRESS-%esi).
                   1211:         */
                   1212:        movl    $VM_MAXUSER_ADDRESS,%eax
                   1213:        subl    %esi,%eax
                   1214:        cmpl    %edx,%eax
                   1215:        jae     1f
                   1216:        movl    %eax,%edx
                   1217:        movl    %eax,20(%esp)
                   1218:
                   1219: 1:     incl    %edx
                   1220:        cld
                   1221:
                   1222: 1:     decl    %edx
                   1223:        jz      2f
                   1224:        lodsb
                   1225:        stosb
                   1226:        testb   %al,%al
                   1227:        jnz     1b
                   1228:
                   1229:        /* Success -- 0 byte reached. */
                   1230:        decl    %edx
                   1231:        xorl    %eax,%eax
                   1232:        jmp     copystr_return
                   1233:
                   1234: 2:     /* edx is zero -- return EFAULT or ENAMETOOLONG. */
                   1235:        cmpl    $VM_MAXUSER_ADDRESS,%esi
                   1236:        jae     _C_LABEL(copystr_efault)
                   1237:        movl    $ENAMETOOLONG,%eax
                   1238:        jmp     copystr_return
                   1239:
                   1240: /* LINTSTUB: Ignore */
                   1241: NENTRY(copystr_efault)
                   1242:        movl    $EFAULT,%eax
                   1243:
                   1244: /* LINTSTUB: Ignore */
                   1245: NENTRY(copystr_fault)
                   1246: copystr_return:
                   1247:        /* Set *lencopied and return %eax. */
                   1248:        GET_CURPCB(%ecx)
                   1249:        movl    $0,PCB_ONFAULT(%ecx)
                   1250:        movl    20(%esp),%ecx
                   1251:        subl    %edx,%ecx
                   1252:        movl    24(%esp),%edx
                   1253:        testl   %edx,%edx
                   1254:        jz      8f
                   1255:        movl    %ecx,(%edx)
                   1256:
                   1257: 8:     popl    %edi
                   1258:        popl    %esi
                   1259:        ret
                   1260:
                   1261: /*
                   1262:  * int copystr(const void *from, void *to, size_t maxlen, size_t *lencopied);
                   1263:  * Copy a NUL-terminated string, at most maxlen characters long.  Return the
                   1264:  * number of characters copied (including the NUL) in *lencopied.  If the
                   1265:  * string is too long, return ENAMETOOLONG; else return 0.
                   1266:  * see copystr(9)
                   1267:  */
                   1268: /* LINTSTUB: Func: int copystr(const void *kfaddr, void *kdaddr, size_t len, size_t *done) */
                   1269: ENTRY(copystr)
                   1270:        pushl   %esi
                   1271:        pushl   %edi
                   1272:
                   1273:        movl    12(%esp),%esi           # esi = from
                   1274:        movl    16(%esp),%edi           # edi = to
                   1275:        movl    20(%esp),%edx           # edx = maxlen
                   1276:        incl    %edx
                   1277:        cld
                   1278:
                   1279: 1:     decl    %edx
                   1280:        jz      4f
                   1281:        lodsb
                   1282:        stosb
                   1283:        testb   %al,%al
                   1284:        jnz     1b
                   1285:
                   1286:        /* Success -- 0 byte reached. */
                   1287:        decl    %edx
                   1288:        xorl    %eax,%eax
                   1289:        jmp     6f
                   1290:
                   1291: 4:     /* edx is zero -- return ENAMETOOLONG. */
                   1292:        movl    $ENAMETOOLONG,%eax
                   1293:
                   1294: 6:     /* Set *lencopied and return %eax. */
                   1295:        movl    20(%esp),%ecx
                   1296:        subl    %edx,%ecx
                   1297:        movl    24(%esp),%edx
                   1298:        testl   %edx,%edx
                   1299:        jz      7f
                   1300:        movl    %ecx,(%edx)
                   1301:
                   1302: 7:     popl    %edi
                   1303:        popl    %esi
                   1304:        ret
                   1305:
                   1306: /*
                   1307:  * long fuword(const void *uaddr);
                   1308:  * Fetch an int from the user's address space.
                   1309:  * see fuword(9)
                   1310:  */
                   1311: /* LINTSTUB: Func: long fuword(const void *base) */
                   1312: ENTRY(fuword)
                   1313:        movl    4(%esp),%edx
                   1314:        cmpl    $VM_MAXUSER_ADDRESS-4,%edx
                   1315:        ja      _C_LABEL(fusuaddrfault)
                   1316:        GET_CURPCB(%ecx)
                   1317:        movl    $_C_LABEL(fusufault),PCB_ONFAULT(%ecx)
                   1318:        movl    (%edx),%eax
                   1319:        movl    $0,PCB_ONFAULT(%ecx)
                   1320:        ret
                   1321:
                   1322: /*
                   1323:  * int fusword(const void *uaddr);
                   1324:  * Fetch a short from the user's address space.
                   1325:  * see fusword(9)
                   1326:  */
                   1327: /* LINTSTUB: Func: int fusword(const void *base) */
                   1328: ENTRY(fusword)
                   1329:        movl    4(%esp),%edx
                   1330:        cmpl    $VM_MAXUSER_ADDRESS-2,%edx
                   1331:        ja      _C_LABEL(fusuaddrfault)
                   1332:        GET_CURPCB(%ecx)
                   1333:        movl    $_C_LABEL(fusufault),PCB_ONFAULT(%ecx)
                   1334:        movzwl  (%edx),%eax
                   1335:        movl    $0,PCB_ONFAULT(%ecx)
                   1336:        ret
                   1337:
                   1338: /*
                   1339:  * int fuswintr(const void *uaddr);
                   1340:  * Fetch a short from the user's address space.  Can be called during an
                   1341:  * interrupt.
                   1342:  * see fuswintr(9)
                   1343:  */
                   1344: /* LINTSTUB: Func: int fuswintr(const void *base) */
                   1345: ENTRY(fuswintr)
                   1346:        movl    4(%esp),%edx
                   1347:        cmpl    $VM_MAXUSER_ADDRESS-2,%edx
                   1348:        ja      _C_LABEL(fusuaddrfault)
                   1349:        movl    CPUVAR(CURPROC),%ecx
                   1350:        movl    P_ADDR(%ecx),%ecx
                   1351:        movl    $_C_LABEL(fusubail),PCB_ONFAULT(%ecx)
                   1352:        movzwl  (%edx),%eax
                   1353:        movl    $0,PCB_ONFAULT(%ecx)
                   1354:        ret
                   1355:
                   1356: /*
                   1357:  * int fubyte(const void *uaddr);
                   1358:  * Fetch a byte from the user's address space.
                   1359:  * see fubyte(9)
                   1360:  */
                   1361: /* LINTSTUB: Func: int fubyte(const void *base) */
                   1362: ENTRY(fubyte)
                   1363:        movl    4(%esp),%edx
                   1364:        cmpl    $VM_MAXUSER_ADDRESS-1,%edx
                   1365:        ja      _C_LABEL(fusuaddrfault)
                   1366:        GET_CURPCB(%ecx)
                   1367:        movl    $_C_LABEL(fusufault),PCB_ONFAULT(%ecx)
                   1368:        movzbl  (%edx),%eax
                   1369:        movl    $0,PCB_ONFAULT(%ecx)
                   1370:        ret
                   1371:
                   1372: /*
                   1373:  * Handle faults from [fs]u*().  Clean up and return -1.
                   1374:  */
                   1375: /* LINTSTUB: Ignore */
                   1376: NENTRY(fusufault)
                   1377:        movl    $0,PCB_ONFAULT(%ecx)
                   1378:        movl    $-1,%eax
                   1379:        ret
                   1380:
                   1381: /*
                   1382:  * Handle faults from [fs]u*().  Clean up and return -1.  This differs from
                   1383:  * fusufault() in that trap() will recognize it and return immediately rather
                   1384:  * than trying to page fault.
                   1385:  */
                   1386: /* LINTSTUB: Ignore */
                   1387: NENTRY(fusubail)
                   1388:        movl    $0,PCB_ONFAULT(%ecx)
                   1389:        movl    $-1,%eax
                   1390:        ret
                   1391:
                   1392: /*
                   1393:  * Handle earlier faults from [fs]u*(), due to our of range addresses.
                   1394:  */
                   1395: /* LINTSTUB: Ignore */
                   1396: NENTRY(fusuaddrfault)
                   1397:        movl    $-1,%eax
                   1398:        ret
                   1399:
                   1400: /*
                   1401:  * int suword(void *uaddr, long x);
                   1402:  * Store an int in the user's address space.
                   1403:  * see suword(9)
                   1404:  */
                   1405: /* LINTSTUB: Func: int suword(void *base, long c) */
                   1406: ENTRY(suword)
                   1407:        movl    4(%esp),%edx
                   1408:        cmpl    $VM_MAXUSER_ADDRESS-4,%edx
                   1409:        ja      _C_LABEL(fusuaddrfault)
                   1410:
                   1411: #if defined(I386_CPU)
                   1412: #if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)
                   1413:        cmpl    $CPUCLASS_386,_C_LABEL(cpu_class)
                   1414:        jne     2f
                   1415: #endif /* I486_CPU || I586_CPU || I686_CPU */
                   1416:
                   1417:        GET_CURPCB(%eax)
                   1418:        movl    $3f,PCB_ONFAULT(%eax)
                   1419:
                   1420:        movl    %edx,%eax
                   1421:        shrl    $PGSHIFT,%eax           # calculate pte address
                   1422:        testb   $PG_RW,_C_LABEL(PTmap)(,%eax,4)
                   1423:        jnz     1f
                   1424:
                   1425: 3:     /* Simulate a trap. */
                   1426:        pushl   %edx
                   1427:        pushl   %edx
                   1428:        call    _C_LABEL(trapwrite)     # trapwrite(addr)
                   1429:        addl    $4,%esp                 # clear parameter from the stack
                   1430:        popl    %edx
                   1431:        GET_CURPCB(%ecx)
                   1432:        testl   %eax,%eax
                   1433:        jnz     _C_LABEL(fusufault)
                   1434:
                   1435: 1:     /* XXX also need to check the following 3 bytes for validity! */
                   1436: #endif
                   1437:
                   1438: 2:     GET_CURPCB(%ecx)
                   1439:        movl    $_C_LABEL(fusufault),PCB_ONFAULT(%ecx)
                   1440:
                   1441:        movl    8(%esp),%eax
                   1442:        movl    %eax,(%edx)
                   1443:        xorl    %eax,%eax
                   1444:        movl    %eax,PCB_ONFAULT(%ecx)
                   1445:        ret
                   1446:
                   1447: /*
                   1448:  * int susword(void *uaddr, short x);
                   1449:  * Store a short in the user's address space.
                   1450:  * see susword(9)
                   1451:  */
                   1452: /* LINTSTUB: Func: int susword(void *base, short c) */
                   1453: ENTRY(susword)
                   1454:        movl    4(%esp),%edx
                   1455:        cmpl    $VM_MAXUSER_ADDRESS-2,%edx
                   1456:        ja      _C_LABEL(fusuaddrfault)
                   1457:
                   1458: #if defined(I386_CPU)
                   1459: #if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)
                   1460:        cmpl    $CPUCLASS_386,_C_LABEL(cpu_class)
                   1461:        jne     2f
                   1462: #endif /* I486_CPU || I586_CPU || I686_CPU */
                   1463:
                   1464:        GET_CURPCB(%eax)
                   1465:        movl    $3f,PCB_ONFAULT(%eax)
                   1466:
                   1467:        movl    %edx,%eax
                   1468:        shrl    $PGSHIFT,%eax           # calculate pte address
                   1469:        testb   $PG_RW,_C_LABEL(PTmap)(,%eax,4)
                   1470:        jnz     1f
                   1471:
                   1472: 3:     /* Simulate a trap. */
                   1473:        pushl   %edx
                   1474:        pushl   %edx
                   1475:        call    _C_LABEL(trapwrite)     # trapwrite(addr)
                   1476:        addl    $4,%esp                 # clear parameter from the stack
                   1477:        popl    %edx
                   1478:        GET_CURPCB(%ecx)
                   1479:        testl   %eax,%eax
                   1480:        jnz     _C_LABEL(fusufault)
                   1481:
                   1482: 1:     /* XXX also need to check the following byte for validity! */
                   1483: #endif
                   1484:
                   1485: 2:     GET_CURPCB(%ecx)
                   1486:        movl    $_C_LABEL(fusufault),PCB_ONFAULT(%ecx)
                   1487:
                   1488:        movl    8(%esp),%eax
                   1489:        movw    %ax,(%edx)
                   1490:        xorl    %eax,%eax
                   1491:        movl    %eax,PCB_ONFAULT(%ecx)
                   1492:        ret
                   1493:
                   1494: /*
                   1495:  * int suswintr(void *uaddr, short x);
                   1496:  * Store a short in the user's address space.  Can be called during an
                   1497:  * interrupt.
                   1498:  * see suswintr(9)
                   1499:  */
                   1500: /* LINTSTUB: Func: int suswintr(void *base, short c) */
                   1501: ENTRY(suswintr)
                   1502:        movl    4(%esp),%edx
                   1503:        cmpl    $VM_MAXUSER_ADDRESS-2,%edx
                   1504:        ja      _C_LABEL(fusuaddrfault)
                   1505:        movl    CPUVAR(CURPROC),%ecx
                   1506:        movl    P_ADDR(%ecx),%ecx
                   1507:        movl    $_C_LABEL(fusubail),PCB_ONFAULT(%ecx)
                   1508:
                   1509: #if defined(I386_CPU)
                   1510: #if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)
                   1511:        cmpl    $CPUCLASS_386,_C_LABEL(cpu_class)
                   1512:        jne     2f
                   1513: #endif /* I486_CPU || I586_CPU || I686_CPU */
                   1514:
                   1515:        movl    %edx,%eax
                   1516:        shrl    $PGSHIFT,%eax           # calculate pte address
                   1517:        testb   $PG_RW,_C_LABEL(PTmap)(,%eax,4)
                   1518:        jnz     1f
                   1519:
                   1520:        /* Simulate a trap. */
                   1521:        jmp     _C_LABEL(fusubail)
                   1522:
                   1523: 1:     /* XXX also need to check the following byte for validity! */
                   1524: #endif
                   1525:
                   1526: 2:     movl    8(%esp),%eax
                   1527:        movw    %ax,(%edx)
                   1528:        xorl    %eax,%eax
                   1529:        movl    %eax,PCB_ONFAULT(%ecx)
                   1530:        ret
                   1531:
                   1532: /*
                   1533:  * int subyte(void *uaddr, char x);
                   1534:  * Store a byte in the user's address space.
                   1535:  * see subyte(9)
                   1536:  */
                   1537: /* LINTSTUB: Func: int subyte(void *base, int c) */
                   1538: ENTRY(subyte)
                   1539:        movl    4(%esp),%edx
                   1540:        cmpl    $VM_MAXUSER_ADDRESS-1,%edx
                   1541:        ja      _C_LABEL(fusuaddrfault)
                   1542:
                   1543: #if defined(I386_CPU)
                   1544: #if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)
                   1545:        cmpl    $CPUCLASS_386,_C_LABEL(cpu_class)
                   1546:        jne     2f
                   1547: #endif /* I486_CPU || I586_CPU || I686_CPU */
                   1548:
                   1549:        GET_CURPCB(%eax)
                   1550:        movl    $3f,PCB_ONFAULT(%eax)
                   1551:
                   1552:        movl    %edx,%eax
                   1553:        shrl    $PGSHIFT,%eax           # calculate pte address
                   1554:        testb   $PG_RW,_C_LABEL(PTmap)(,%eax,4)
                   1555:        jnz     1f
                   1556:
                   1557: 3:     /* Simulate a trap. */
                   1558:        pushl   %edx
                   1559:        pushl   %edx
                   1560:        call    _C_LABEL(trapwrite)     # trapwrite(addr)
                   1561:        addl    $4,%esp                 # clear parameter from the stack
                   1562:        popl    %edx
                   1563:        GET_CURPCB(%ecx)
                   1564:        testl   %eax,%eax
                   1565:        jnz     _C_LABEL(fusufault)
                   1566:
                   1567: 1:
                   1568: #endif
                   1569:
                   1570: 2:     GET_CURPCB(%ecx)
                   1571:        movl    $_C_LABEL(fusufault),PCB_ONFAULT(%ecx)
                   1572:
                   1573:        movb    8(%esp),%al
                   1574:        movb    %al,(%edx)
                   1575:        xorl    %eax,%eax
                   1576:        movl    %eax,PCB_ONFAULT(%ecx)
                   1577:        ret
                   1578:
                   1579: /*****************************************************************************/
                   1580:
                   1581: /*
                   1582:  * The following is i386-specific nonsense.
                   1583:  */
                   1584:
                   1585: /*
                   1586:  * void lgdt(struct region_descriptor *rdp);
                   1587:  * Load a new GDT pointer (and do any necessary cleanup).
                   1588:  * XXX It's somewhat questionable whether reloading all the segment registers
                   1589:  * is necessary, since the actual descriptor data is not changed except by
                   1590:  * process creation and exit, both of which clean up via task switches.  OTOH,
                   1591:  * this only happens at run time when the GDT is resized.
                   1592:  */
                   1593: /* LINTSTUB: Func: void lgdt(struct region_descriptor *rdp) */
                   1594: NENTRY(lgdt)
                   1595:        /* Reload the descriptor table. */
                   1596:        movl    4(%esp),%eax
                   1597:        lgdt    (%eax)
                   1598:        /* Flush the prefetch queue. */
                   1599:        jmp     1f
                   1600:        nop
                   1601: 1:     /* Reload "stale" selectors. */
                   1602:        movl    $GSEL(GDATA_SEL, SEL_KPL),%eax
                   1603:        movw    %ax,%ds
                   1604:        movw    %ax,%es
                   1605:        movw    %ax,%gs
                   1606:        movw    %ax,%ss
                   1607:        movl    $GSEL(GCPU_SEL, SEL_KPL),%eax
                   1608:        movw    %ax,%fs
                   1609:        /* Reload code selector by doing intersegment return. */
                   1610:        popl    %eax
                   1611:        pushl   $GSEL(GCODE_SEL, SEL_KPL)
                   1612:        pushl   %eax
                   1613:        lret
                   1614:
                   1615: /*****************************************************************************/
                   1616:
                   1617: /*
                   1618:  * These functions are primarily used by DDB.
                   1619:  */
                   1620:
                   1621: /* LINTSTUB: Func: int setjmp (label_t *l) */
                   1622: ENTRY(setjmp)
                   1623:        movl    4(%esp),%eax
                   1624:        movl    %ebx,(%eax)             # save ebx
                   1625:        movl    %esp,4(%eax)            # save esp
                   1626:        movl    %ebp,8(%eax)            # save ebp
                   1627:        movl    %esi,12(%eax)           # save esi
                   1628:        movl    %edi,16(%eax)           # save edi
                   1629:        movl    (%esp),%edx             # get rta
                   1630:        movl    %edx,20(%eax)           # save eip
                   1631:        xorl    %eax,%eax               # return (0);
                   1632:        ret
                   1633:
                   1634: /* LINTSTUB: Func: void longjmp (label_t *l) */
                   1635: ENTRY(longjmp)
                   1636:        movl    4(%esp),%eax
                   1637:        movl    (%eax),%ebx             # restore ebx
                   1638:        movl    4(%eax),%esp            # restore esp
                   1639:        movl    8(%eax),%ebp            # restore ebp
                   1640:        movl    12(%eax),%esi           # restore esi
                   1641:        movl    16(%eax),%edi           # restore edi
                   1642:        movl    20(%eax),%edx           # get rta
                   1643:        movl    %edx,(%esp)             # put in return frame
                   1644:        xorl    %eax,%eax               # return (1);
                   1645:        incl    %eax
                   1646:        ret
                   1647:
                   1648: /*****************************************************************************/
                   1649:
                   1650:        .globl  _C_LABEL(sched_whichqs),_C_LABEL(sched_qs)
                   1651:        .globl  _C_LABEL(uvmexp),_C_LABEL(panic)
                   1652:
                   1653: #ifdef DIAGNOSTIC
                   1654: NENTRY(switch_error)
                   1655:        pushl   $1f
                   1656:        call    _C_LABEL(panic)
                   1657:        /* NOTREACHED */
                   1658: 1:     .asciz  "cpu_switch"
                   1659: #endif /* DIAGNOSTIC */
                   1660:
                   1661: /*
                   1662:  * void cpu_switch(struct proc *)
                   1663:  * Find a runnable process and switch to it.  Wait if necessary.  If the new
                   1664:  * process is the same as the old one, we short-circuit the context save and
                   1665:  * restore.
                   1666:  *
                   1667:  * Note that the stack frame layout is known to "struct switchframe"
                   1668:  * in <machine/frame.h> and to the code in cpu_fork() which initializes
                   1669:  * it for a new process.
                   1670:  */
                   1671: ENTRY(cpu_switch)
                   1672:        pushl   %ebx
                   1673:        pushl   %esi
                   1674:        pushl   %edi
                   1675:
                   1676: #ifdef DEBUG
                   1677:        cmpl    $IPL_SCHED,CPUVAR(ILEVEL)
                   1678:        jae     1f
                   1679:        pushl   2f
                   1680:        call    _C_LABEL(panic)
                   1681:        /* NOTREACHED */
                   1682: 2:     .asciz  "not splhigh() in cpu_switch!"
                   1683:
                   1684: 1:
                   1685: #endif /* DEBUG */
                   1686:
                   1687:        movl    CPUVAR(CURPROC),%esi
                   1688:
                   1689:        /*
                   1690:         * Clear curproc so that we don't accumulate system time while idle.
                   1691:         * This also insures that schedcpu() will move the old process to
                   1692:         * the correct queue if it happens to get called from the spllower()
                   1693:         * below and changes the priority.  (See corresponding comment in
                   1694:         * userret()).
                   1695:         */
                   1696:        movl    $0,CPUVAR(CURPROC)
                   1697:        /*
                   1698:         * First phase: find new process.
                   1699:         *
                   1700:         * Registers:
                   1701:         *   %eax - queue head, scratch, then zero
                   1702:         *   %ebx - queue number
                   1703:         *   %ecx - cached value of whichqs
                   1704:         *   %edx - next process in queue
                   1705:         *   %esi - old process
                   1706:         *   %edi - new process
                   1707:         */
                   1708:
                   1709:        /* Look for new process. */
                   1710:        cli                             # splhigh doesn't do a cli
                   1711:        movl    _C_LABEL(sched_whichqs),%ecx
                   1712:        bsfl    %ecx,%ebx               # find a full q
                   1713:        jnz     switch_dequeue
                   1714:
                   1715:        /*
                   1716:         * idling:      save old context.
                   1717:         *
                   1718:         * Registers:
                   1719:         *   %eax, %ecx - scratch
                   1720:         *   %esi - old process, then old pcb
                   1721:         *   %edi - idle pcb
                   1722:         */
                   1723:
                   1724:        pushl   %esi
                   1725:        call    _C_LABEL(pmap_deactivate)       # pmap_deactivate(oldproc)
                   1726:        addl    $4,%esp
                   1727:
                   1728:        movl    P_ADDR(%esi),%esi
                   1729:
                   1730:        /* Save stack pointers. */
                   1731:        movl    %esp,PCB_ESP(%esi)
                   1732:        movl    %ebp,PCB_EBP(%esi)
                   1733:
                   1734:        /* Find idle PCB for this CPU */
                   1735: #ifndef MULTIPROCESSOR
                   1736:        movl    $_C_LABEL(proc0),%ebx
                   1737:        movl    P_ADDR(%ebx),%edi
                   1738:        movl    P_MD_TSS_SEL(%ebx),%edx
                   1739: #else
                   1740:        movl    CPUVAR(IDLE_PCB),%edi
                   1741:        movl    CPUVAR(IDLE_TSS_SEL),%edx
                   1742: #endif
                   1743:        movl    $0,CPUVAR(CURPROC)              /* In case we fault... */
                   1744:
                   1745:        /* Restore the idle context (avoid interrupts) */
                   1746:        cli
                   1747:
                   1748:        /* Restore stack pointers. */
                   1749:        movl    PCB_ESP(%edi),%esp
                   1750:        movl    PCB_EBP(%edi),%ebp
                   1751:
                   1752:
                   1753:        /* Switch address space. */
                   1754:        movl    PCB_CR3(%edi),%ecx
                   1755:        movl    %ecx,%cr3
                   1756:
                   1757:        /* Switch TSS. Reset "task busy" flag before loading. */
                   1758: #ifdef MULTIPROCESSOR
                   1759:        movl    CPUVAR(GDT),%eax
                   1760: #else
                   1761:        movl    _C_LABEL(gdt),%eax
                   1762: #endif
                   1763:        andl    $~0x0200,4-SEL_KPL(%eax,%edx,1)
                   1764:        ltr     %dx
                   1765:
                   1766:        /* We're always in the kernel, so we don't need the LDT. */
                   1767:
                   1768:        /* Restore cr0 (including FPU state). */
                   1769:        movl    PCB_CR0(%edi),%ecx
                   1770:        movl    %ecx,%cr0
                   1771:
                   1772:        /* Record new pcb. */
                   1773:        SET_CURPCB(%edi)
                   1774:
                   1775:        xorl    %esi,%esi
                   1776:        sti
                   1777: idle_unlock:
                   1778: #if defined(MULTIPROCESSOR) || defined(LOCKDEBUG)
                   1779:        call    _C_LABEL(sched_unlock_idle)
                   1780: #endif
                   1781:        /* Interrupts are okay again. */
1.2       fvdl     1782:        pushl   $IPL_NONE               # spl0()
1.1       fvdl     1783:        call    _C_LABEL(Xspllower)     # process pending interrupts
1.2       fvdl     1784:        addl    $4,%esp
1.1       fvdl     1785:        jmp     idle_start
                   1786: idle_zero:
                   1787:        sti
                   1788:        call    _C_LABEL(uvm_pageidlezero)
                   1789:        cli
                   1790:        cmpl    $0,_C_LABEL(sched_whichqs)
                   1791:        jnz     idle_exit
                   1792: idle_loop:
                   1793:        /* Try to zero some pages. */
                   1794:        movl    _C_LABEL(uvm)+UVM_PAGE_IDLE_ZERO,%ecx
                   1795:        testl   %ecx,%ecx
                   1796:        jnz     idle_zero
                   1797:        sti
                   1798:        hlt
                   1799: NENTRY(mpidle)
                   1800: idle_start:
                   1801:        cli
                   1802:        cmpl    $0,_C_LABEL(sched_whichqs)
                   1803:        jz      idle_loop
                   1804: idle_exit:
                   1805:        movl    $IPL_HIGH,CPUVAR(ILEVEL)                # splhigh
                   1806: #if defined(MULTIPROCESSOR) || defined(LOCKDEBUG)
                   1807:        call    _C_LABEL(sched_lock_idle)
                   1808: #endif
                   1809:        movl    _C_LABEL(sched_whichqs),%ecx
                   1810:        bsfl    %ecx,%ebx
                   1811:        jz      idle_unlock
                   1812:
                   1813: switch_dequeue:
                   1814:        /*
                   1815:         * we're running at splhigh(), but it's otherwise okay to take
                   1816:         * interrupts here.
                   1817:         */
                   1818:        sti
                   1819:        leal    _C_LABEL(sched_qs)(,%ebx,8),%eax # select q
                   1820:
                   1821:        movl    P_FORW(%eax),%edi       # unlink from front of process q
                   1822: #ifdef DIAGNOSTIC
                   1823:        cmpl    %edi,%eax               # linked to self (i.e. nothing queued)?
                   1824:        je      _C_LABEL(switch_error)  # not possible
                   1825: #endif /* DIAGNOSTIC */
                   1826:        movl    P_FORW(%edi),%edx
                   1827:        movl    %edx,P_FORW(%eax)
                   1828:        movl    %eax,P_BACK(%edx)
                   1829:
                   1830:        cmpl    %edx,%eax               # q empty?
                   1831:        jne     3f
                   1832:
                   1833:        btrl    %ebx,%ecx               # yes, clear to indicate empty
                   1834:        movl    %ecx,_C_LABEL(sched_whichqs) # update q status
                   1835:
                   1836: 3:     /* We just did it. */
                   1837:        xorl    %eax,%eax
                   1838:        CLEAR_RESCHED(%eax)
                   1839:
                   1840: #ifdef DIAGNOSTIC
                   1841:        cmpl    %eax,P_WCHAN(%edi)      # Waiting for something?
                   1842:        jne     _C_LABEL(switch_error)  # Yes; shouldn't be queued.
                   1843:        cmpb    $SRUN,P_STAT(%edi)      # In run state?
                   1844:        jne     _C_LABEL(switch_error)  # No; shouldn't be queued.
                   1845: #endif /* DIAGNOSTIC */
                   1846:
                   1847:        /* Isolate process.  XXX Is this necessary? */
                   1848:        movl    %eax,P_BACK(%edi)
                   1849:
                   1850:        /* Record new process. */
                   1851:        movb    $SONPROC,P_STAT(%edi)   # p->p_stat = SONPROC
                   1852:        SET_CURPROC(%edi,%ecx)
                   1853:
                   1854:        /* Skip context switch if same process. */
                   1855:        cmpl    %edi,%esi
                   1856:        je      switch_return
                   1857:
                   1858:        /* If old process exited, don't bother. */
                   1859:        testl   %esi,%esi
                   1860:        jz      switch_exited
                   1861:
                   1862:        /*
                   1863:         * Second phase: save old context.
                   1864:         *
                   1865:         * Registers:
                   1866:         *   %eax, %ecx - scratch
                   1867:         *   %esi - old process, then old pcb
                   1868:         *   %edi - new process
                   1869:         */
                   1870:
                   1871:        pushl   %esi
                   1872:        call    _C_LABEL(pmap_deactivate)       # pmap_deactivate(oldproc)
                   1873:        addl    $4,%esp
                   1874:
                   1875:        movl    P_ADDR(%esi),%esi
                   1876:
                   1877:        /* Save stack pointers. */
                   1878:        movl    %esp,PCB_ESP(%esi)
                   1879:        movl    %ebp,PCB_EBP(%esi)
                   1880:
                   1881: switch_exited:
                   1882:        /*
                   1883:         * Third phase: restore saved context.
                   1884:         *
                   1885:         * Registers:
                   1886:         *   %eax, %ebx, %ecx, %edx - scratch
                   1887:         *   %esi - new pcb
                   1888:         *   %edi - new process
                   1889:         */
                   1890:
                   1891:        /* No interrupts while loading new state. */
                   1892:        cli
                   1893:        movl    P_ADDR(%edi),%esi
                   1894:
                   1895:        /* Restore stack pointers. */
                   1896:        movl    PCB_ESP(%esi),%esp
                   1897:        movl    PCB_EBP(%esi),%ebp
                   1898:
                   1899: #if 0
                   1900:        /* Don't bother with the rest if switching to a system process. */
                   1901:        testl   $P_SYSTEM,P_FLAG(%edi)
                   1902:        jnz     switch_restored
                   1903: #endif
                   1904:
                   1905: #ifdef MULTIPROCESSOR
                   1906:        movl    CPUVAR(GDT),%eax
                   1907: #else
                   1908:        /* Load TSS info. */
                   1909:        movl    _C_LABEL(gdt),%eax
                   1910: #endif
                   1911:        movl    P_MD_TSS_SEL(%edi),%edx
                   1912:
                   1913:        /* Switch TSS. Reset "task busy" flag before loading. */
                   1914:        andl    $~0x0200,4(%eax,%edx, 1)
                   1915:        ltr     %dx
                   1916:
                   1917:        pushl   %edi
                   1918:        call    _C_LABEL(pmap_activate)         # pmap_activate(p)
                   1919:        addl    $4,%esp
                   1920:
                   1921: #if 0
                   1922: switch_restored:
                   1923: #endif
                   1924:        /* Restore cr0 (including FPU state). */
                   1925:        movl    PCB_CR0(%esi),%ecx
                   1926: #ifdef MULTIPROCESSOR
                   1927:        /*
                   1928:         * If our floating point registers are on a different cpu,
                   1929:         * clear CR0_TS so we'll trap rather than reuse bogus state.
                   1930:         */
                   1931:        movl    PCB_FPCPU(%esi),%ebx
                   1932:        cmpl    CPUVAR(SELF),%ebx
                   1933:        jz      1f
                   1934:        orl     $CR0_TS,%ecx
                   1935: 1:
                   1936: #endif
                   1937:        movl    %ecx,%cr0
                   1938:
                   1939:        /* Record new pcb. */
                   1940:        SET_CURPCB(%esi)
                   1941:
                   1942:        /* Interrupts are okay again. */
                   1943:        sti
                   1944:
                   1945: /*
                   1946:  *  Check for restartable atomic sequences (RAS)
                   1947:  *  XXX %edi reloads are not necessary here as %edi is callee-saved!
                   1948:  */
                   1949:        movl    CPUVAR(CURPROC),%edi
                   1950:        cmpl    $0,P_NRAS(%edi)
                   1951:        je      1f
                   1952:        movl    P_MD_REGS(%edi),%edx
                   1953:        movl    TF_EIP(%edx),%eax
                   1954:        pushl   %eax
                   1955:        pushl   %edi
                   1956:        call    _C_LABEL(ras_lookup)
                   1957:        addl    $8,%esp
                   1958:        cmpl    $-1,%eax
                   1959:        je      1f
                   1960:        movl    CPUVAR(CURPROC),%edi
                   1961:        movl    P_MD_REGS(%edi),%edx
                   1962:        movl    %eax,TF_EIP(%edx)
                   1963: 1:
                   1964:
                   1965: switch_return:
                   1966: #if defined(MULTIPROCESSOR) || defined(LOCKDEBUG)
                   1967:        call    _C_LABEL(sched_unlock_idle)
                   1968: #endif
1.2       fvdl     1969:        pushl   $IPL_NONE               # spl0()
1.1       fvdl     1970:        call    _C_LABEL(Xspllower)     # process pending interrupts
1.2       fvdl     1971:        addl    $4,%esp
1.1       fvdl     1972:        movl    $IPL_HIGH,CPUVAR(ILEVEL)        # splhigh()
                   1973:
                   1974:        movl    %edi,%eax               # return (p);
                   1975:        popl    %edi
                   1976:        popl    %esi
                   1977:        popl    %ebx
                   1978:        ret
                   1979:
                   1980: /*
                   1981:  * void switch_exit(struct proc *p);
                   1982:  * switch_exit(struct proc *p);
                   1983:  * Switch to the appropriate idle context (proc0's if uniprocessor; the cpu's
                   1984:  * if multiprocessor) and deallocate the address space and kernel stack for p.
                   1985:  * Then jump into cpu_switch(), as if we were in the idle proc all along.
                   1986:  */
                   1987: #ifndef MULTIPROCESSOR
                   1988:        .globl  _C_LABEL(proc0)
                   1989: #endif
                   1990:        .globl  _C_LABEL(uvmspace_free),_C_LABEL(kernel_map)
                   1991:        .globl  _C_LABEL(uvm_km_free),_C_LABEL(tss_free)
                   1992: /* LINTSTUB: Func: void switch_exit(struct proc *p) */
                   1993: ENTRY(switch_exit)
                   1994:        movl    4(%esp),%edi            # old process
                   1995: #ifndef MULTIPROCESSOR
                   1996:        movl    $_C_LABEL(proc0),%ebx
                   1997:        movl    P_ADDR(%ebx),%esi
                   1998:        movl    P_MD_TSS_SEL(%ebx),%edx
                   1999: #else
                   2000:        movl    CPUVAR(IDLE_PCB),%esi
                   2001:        movl    CPUVAR(IDLE_TSS_SEL),%edx
                   2002: #endif
                   2003:        /* In case we fault... */
                   2004:        movl    $0,CPUVAR(CURPROC)
                   2005:
                   2006:        /* Restore the idle context. */
                   2007:        cli
                   2008:
                   2009:        /* Restore stack pointers. */
                   2010:        movl    PCB_ESP(%esi),%esp
                   2011:        movl    PCB_EBP(%esi),%ebp
                   2012:
                   2013:        /* Load TSS info. */
                   2014: #ifdef MULTIPROCESSOR
                   2015:        movl    CPUVAR(GDT),%eax
                   2016: #else
                   2017:        /* Load TSS info. */
                   2018:        movl    _C_LABEL(gdt),%eax
                   2019: #endif
                   2020:
                   2021:        /* Switch address space. */
                   2022:        movl    PCB_CR3(%esi),%ecx
                   2023:        movl    %ecx,%cr3
                   2024:
                   2025:        /* Switch TSS. */
                   2026:        andl    $~0x0200,4-SEL_KPL(%eax,%edx,1)
                   2027:        ltr     %dx
                   2028:
                   2029:        /* We're always in the kernel, so we don't need the LDT. */
                   2030:
                   2031:        /* Restore cr0 (including FPU state). */
                   2032:        movl    PCB_CR0(%esi),%ecx
                   2033:        movl    %ecx,%cr0
                   2034:
                   2035:        /* Record new pcb. */
                   2036:        SET_CURPCB(%esi)
                   2037:
                   2038:        /* Interrupts are okay again. */
                   2039:        sti
                   2040:
                   2041:        /*
                   2042:         * Schedule the dead process's vmspace and stack to be freed.
                   2043:         */
                   2044:        pushl   %edi                    /* exit2(p) */
                   2045:        call    _C_LABEL(exit2)
                   2046:        addl    $4,%esp
                   2047:
                   2048:        /* Jump into cpu_switch() with the right state. */
                   2049:        xorl    %esi,%esi
                   2050:        movl    %esi,CPUVAR(CURPROC)
                   2051:        jmp     idle_start
                   2052:
                   2053: /*
                   2054:  * void savectx(struct pcb *pcb);
                   2055:  * Update pcb, saving current processor state.
                   2056:  */
                   2057: /* LINTSTUB: Func: void savectx(struct pcb *pcb) */
                   2058: ENTRY(savectx)
                   2059:        movl    4(%esp),%edx            # edx = p->p_addr
                   2060:
                   2061:        /* Save stack pointers. */
                   2062:        movl    %esp,PCB_ESP(%edx)
                   2063:        movl    %ebp,PCB_EBP(%edx)
                   2064:
                   2065:        ret
                   2066:
                   2067: /*
                   2068:  * Old call gate entry for syscall
                   2069:  */
                   2070: /* LINTSTUB: Var: char Xosyscall[1]; */
                   2071: IDTVEC(osyscall)
                   2072:        /* Set eflags in trap frame. */
                   2073:        pushfl
                   2074:        popl    8(%esp)
                   2075:        pushl   $7              # size of instruction for restart
                   2076:        jmp     syscall1
                   2077:
                   2078: /*
                   2079:  * Trap gate entry for syscall
                   2080:  */
                   2081: /* LINTSTUB: Var: char Xsyscall[1]; */
                   2082: IDTVEC(syscall)
                   2083:        pushl   $2              # size of instruction for restart
                   2084: syscall1:
                   2085:        pushl   $T_ASTFLT       # trap # for doing ASTs
                   2086:        INTRENTRY
                   2087:
                   2088: #ifdef DIAGNOSTIC
                   2089:        movl    CPUVAR(ILEVEL),%ebx
                   2090:        testl   %ebx,%ebx
                   2091:        jz      1f
                   2092:        pushl   $5f
                   2093:        call    _C_LABEL(printf)
                   2094:        addl    $4,%esp
                   2095: #ifdef DDB
                   2096:        int     $3
                   2097: #endif
                   2098: 1:
                   2099: #endif /* DIAGNOSTIC */
                   2100:        movl    CPUVAR(CURPROC),%edx
                   2101:        movl    %esp,P_MD_REGS(%edx)    # save pointer to frame
                   2102:        call    *P_MD_SYSCALL(%edx)     # get pointer to syscall() function
                   2103: 2:     /* Check for ASTs on exit to user mode. */
                   2104:        cli
                   2105:        CHECK_ASTPENDING()
                   2106:        je      1f
                   2107:        /* Always returning to user mode here. */
                   2108:        CLEAR_ASTPENDING()
                   2109:        sti
                   2110:        /* Pushed T_ASTFLT into tf_trapno on entry. */
                   2111:        call    _C_LABEL(trap)
                   2112:        jmp     2b
                   2113: #ifndef DIAGNOSTIC
                   2114: 1:     INTRFASTEXIT
                   2115: #else /* DIAGNOSTIC */
                   2116: 1:     cmpl    $IPL_NONE,CPUVAR(ILEVEL)
                   2117:        jne     3f
                   2118:        INTRFASTEXIT
                   2119: 3:     sti
                   2120:        pushl   $4f
                   2121:        call    _C_LABEL(printf)
                   2122:        addl    $4,%esp
                   2123: #ifdef DDB
                   2124:        int     $3
                   2125: #endif /* DDB */
                   2126:        movl    $IPL_NONE,CPUVAR(ILEVEL)
                   2127:        jmp     2b
                   2128: 4:     .asciz  "WARNING: SPL NOT LOWERED ON SYSCALL EXIT\n"
                   2129: 5:     .asciz  "WARNING: SPL NOT ZERO ON SYSCALL ENTRY\n"
                   2130: #endif /* DIAGNOSTIC */
                   2131:
                   2132: #if NNPX > 0
                   2133: /*
                   2134:  * Special interrupt handlers.  Someday intr0-intr15 will be used to count
                   2135:  * interrupts.  We'll still need a special exception 16 handler.  The busy
                   2136:  * latch stuff in probintr() can be moved to npxprobe().
                   2137:  */
                   2138:
                   2139: /* LINTSTUB: Func: void probeintr(void) */
                   2140: NENTRY(probeintr)
                   2141:        ss
                   2142:        incl    _C_LABEL(npx_intrs_while_probing)
                   2143:        pushl   %eax
                   2144:        movb    $0x20,%al       # EOI (asm in strings loses cpp features)
                   2145:        outb    %al,$0xa0       # IO_ICU2
                   2146:        outb    %al,$0x20       # IO_ICU1
                   2147:        movb    $0,%al
                   2148:        outb    %al,$0xf0       # clear BUSY# latch
                   2149:        popl    %eax
                   2150:        iret
                   2151:
                   2152: /* LINTSTUB: Func: void probetrap(void) */
                   2153: NENTRY(probetrap)
                   2154:        ss
                   2155:        incl    _C_LABEL(npx_traps_while_probing)
                   2156:        fnclex
                   2157:        iret
                   2158:
                   2159: /* LINTSTUB: Func: int npx586bug1(int a, int b) */
                   2160: NENTRY(npx586bug1)
                   2161:        fildl   4(%esp)         # x
                   2162:        fildl   8(%esp)         # y
                   2163:        fld     %st(1)
                   2164:        fdiv    %st(1),%st      # x/y
                   2165:        fmulp   %st,%st(1)      # (x/y)*y
                   2166:        fsubrp  %st,%st(1)      # x-(x/y)*y
                   2167:        pushl   $0
                   2168:        fistpl  (%esp)
                   2169:        popl    %eax
                   2170:        ret
                   2171: #endif /* NNPX > 0 */

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