locore.s revision 27003
1/*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * William Jolitz. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: @(#)locore.s 7.3 (Berkeley) 5/13/91 37 * $Id: locore.s,v 1.1 1997/06/27 18:33:41 smp Exp smp $ 38 * 39 * originally from: locore.s, by William F. Jolitz 40 * 41 * Substantially rewritten by David Greenman, Rod Grimes, 42 * Bruce Evans, Wolfgang Solfrank, Poul-Henning Kamp 43 * and many others. 44 */ 45 46#include "apm.h" 47#include "opt_cpu.h" 48#include "opt_ddb.h" 49#include "opt_userconfig.h" 50#include "opt_smp.h" 51 52#include <sys/errno.h> 53#include <sys/syscall.h> 54#include <sys/reboot.h> 55 56#include <machine/asmacros.h> 57#include <machine/cputypes.h> 58#include <machine/psl.h> 59#include <machine/pmap.h> 60#include <machine/specialreg.h> 61 62#ifdef SMP 63#include <machine/apic.h> 64#endif /* SMP */ 65 66#include "assym.s" 67 68/* 69 * XXX 70 * 71 * Note: This version greatly munged to avoid various assembler errors 72 * that may be fixed in newer versions of gas. Perhaps newer versions 73 * will have more pleasant appearance. 74 */ 75 76/* 77 * PTmap is recursive pagemap at top of virtual address space. 78 * Within PTmap, the page directory can be found (third indirection). 79 */ 80 .globl _PTmap,_PTD,_PTDpde 81 .set _PTmap,(PTDPTDI << PDRSHIFT) 82 .set _PTD,_PTmap + (PTDPTDI * PAGE_SIZE) 83 .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 84 85/* 86 * APTmap, APTD is the alternate recursive pagemap. 87 * It's used when modifying another process's page tables. 88 */ 89 .globl _APTmap,_APTD,_APTDpde 90 .set _APTmap,APTDPTDI << PDRSHIFT 91 .set _APTD,_APTmap + (APTDPTDI * PAGE_SIZE) 92 .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 93 94#ifdef SMP 95 .globl _SMP_prvstart 96 .set _SMP_prvstart,(MPPTDI << PDRSHIFT) 97 98 .globl _SMP_prvpage,_SMP_prvpt,_lapic,_SMP_ioapic 99 .set _SMP_prvpage,_SMP_prvstart 100 .set _SMP_prvpt,_SMP_prvstart + PAGE_SIZE 101 .set _lapic,_SMP_prvstart + (2 * PAGE_SIZE) 102 .set _SMP_ioapic,_SMP_prvstart + (16 * PAGE_SIZE) 103 104 .globl _cpuid,_curproc,_curpcb,_npxproc,_runtime,_cpu_lockid 105 .globl _common_tss,_other_cpus 106 .set _cpuid,_SMP_prvpage+0 107 .set _curproc,_SMP_prvpage+4 108 .set _curpcb,_SMP_prvpage+8 109 .set _npxproc,_SMP_prvpage+12 110 .set _runtime,_SMP_prvpage+16 /* 8 bytes struct timeval */ 111 .set _cpu_lockid,_SMP_prvpage+24 112 .set _common_tss,_SMP_prvpage+28 /* 104 bytes long, next = 132 */ 113 .set _other_cpus,_SMP_prvpage+132 /* bitmap of available CPUs, 114 excluding ourself */ 115 116/* Fetch the .set's for the local apic */ 117#include "i386/i386/mp_apicdefs.s" 118 119#endif 120 121/* 122 * Globals 123 */ 124 .data 125 ALIGN_DATA /* just to be sure */ 126 127 .globl HIDENAME(tmpstk) 128 .space 0x2000 /* space for tmpstk - temporary stack */ 129HIDENAME(tmpstk): 130 131 .globl _boothowto,_bootdev 132 133 .globl _cpu,_cpu_vendor,_cpu_id,_bootinfo 134 .globl _cpu_high, _cpu_feature 135 136_cpu: .long 0 /* are we 386, 386sx, or 486 */ 137_cpu_id: .long 0 /* stepping ID */ 138_cpu_high: .long 0 /* highest arg to CPUID */ 139_cpu_feature: .long 0 /* features */ 140_cpu_vendor: .space 20 /* CPU origin code */ 141_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 142 143_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 144physfree: .long 0 /* phys addr of next free page */ 145 146#ifdef SMP 147cpu0pp: .long 0 /* phys addr cpu0 private pg */ 148cpu0pt: .long 0 /* phys addr cpu0 private pt */ 149 150 .globl _cpu0prvpage,_cpu0prvpt 151_cpu0prvpage: .long 0 /* relocated version */ 152_cpu0prvpt: .long 0 /* relocated version */ 153#endif /* SMP */ 154 155 .globl _IdlePTD 156_IdlePTD: .long 0 /* phys addr of kernel PTD */ 157 158#ifdef SMP 159 .globl _KPTphys 160#endif 161_KPTphys: .long 0 /* phys addr of kernel page tables */ 162 163 .globl _proc0paddr 164_proc0paddr: .long 0 /* address of proc 0 address space */ 165p0upa: .long 0 /* phys addr of proc0's UPAGES */ 166 167#ifdef BDE_DEBUGGER 168 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 169_bdb_exists: .long 0 170#endif 171 172 173/********************************************************************** 174 * 175 * Some handy macros 176 * 177 */ 178 179#define R(foo) ((foo)-KERNBASE) 180 181#define ALLOCPAGES(foo) \ 182 movl R(physfree), %esi ; \ 183 movl $((foo)*PAGE_SIZE), %eax ; \ 184 addl %esi, %eax ; \ 185 movl %eax, R(physfree) ; \ 186 movl %esi, %edi ; \ 187 movl $((foo)*PAGE_SIZE),%ecx ; \ 188 xorl %eax,%eax ; \ 189 cld ; \ 190 rep ; \ 191 stosb 192 193/* 194 * fillkpt 195 * eax = page frame address 196 * ebx = index into page table 197 * ecx = how many pages to map 198 * base = base address of page dir/table 199 * prot = protection bits 200 */ 201#define fillkpt(base, prot) \ 202 shll $2,%ebx ; \ 203 addl base,%ebx ; \ 204 orl $PG_V,%eax ; \ 205 orl prot,%eax ; \ 2061: movl %eax,(%ebx) ; \ 207 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 208 addl $4,%ebx ; /* next pte */ \ 209 loop 1b 210 211/* 212 * fillkptphys(prot) 213 * eax = physical address 214 * ecx = how many pages to map 215 * prot = protection bits 216 */ 217#define fillkptphys(prot) \ 218 movl %eax, %ebx ; \ 219 shrl $PAGE_SHIFT, %ebx ; \ 220 fillkpt(R(_KPTphys), prot) 221 222 .text 223/********************************************************************** 224 * 225 * This is where the bootblocks start us, set the ball rolling... 226 * 227 */ 228NON_GPROF_ENTRY(btext) 229 230#ifdef PC98 231 jmp 1f 232 .globl _pc98_system_parameter 233 .org 0x400 234_pc98_system_parameter: 235 .space 0x240 /* BIOS parameter block */ 2361: 237 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 238 movl $0xa1000,%esi 239 movl $0x100000,%edi 240 movl $0x0630,%ecx 241 cld 242 rep 243 movsb 244#else /* IBM-PC */ 245#ifdef BDE_DEBUGGER 246#ifdef BIOS_STEALS_3K 247 cmpl $0x0375c339,0x95504 248#else 249 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 250#endif 251 jne 1f 252 movb $1,R(_bdb_exists) 2531: 254#endif 255 256/* Tell the bios to warmboot next time */ 257 movw $0x1234,0x472 258#endif /* PC98 */ 259 260/* Set up a real frame in case the double return in newboot is executed. */ 261 pushl %ebp 262 movl %esp, %ebp 263 264/* Don't trust what the BIOS gives for eflags. */ 265 pushl $PSL_KERNEL 266 popfl 267 268/* 269 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 270 * to set %cs, %ds, %es and %ss. 271 */ 272 mov %ds, %ax 273 mov %ax, %fs 274 mov %ax, %gs 275 276 call recover_bootinfo 277 278/* Get onto a stack that we can trust. */ 279/* 280 * XXX this step is delayed in case recover_bootinfo needs to return via 281 * the old stack, but it need not be, since recover_bootinfo actually 282 * returns via the old frame. 283 */ 284 movl $R(HIDENAME(tmpstk)),%esp 285 286#ifdef PC98 287 testb $0x02,0x100620 /* pc98_machine_type & M_EPSON_PC98 */ 288 jz 3f 289 cmpb $0x0b,0x100624 /* epson_machine_id <= 0x0b */ 290 ja 3f 291 292 /* count up memory */ 293 movl $0x100000,%eax /* next, talley remaining memory */ 294 movl $0xFFF-0x100,%ecx 2951: movl 0(%eax),%ebx /* save location to check */ 296 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 297 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 298 jne 2f 299 movl %ebx,0(%eax) /* restore memory */ 300 addl $PAGE_SIZE,%eax 301 loop 1b 3022: subl $0x100000,%eax 303 shrl $17,%eax 304 movb %al,0x100401 3053: 306#endif 307 308 call identify_cpu 309 310/* clear bss */ 311/* 312 * XXX this should be done a little earlier. 313 * 314 * XXX we don't check that there is memory for our bss and page tables 315 * before using it. 316 * 317 * XXX the boot program somewhat bogusly clears the bss. We still have 318 * to do it in case we were unzipped by kzipboot. Then the boot program 319 * only clears kzipboot's bss. 320 * 321 * XXX the gdt and idt are still somewhere in the boot program. We 322 * depend on the convention that the boot program is below 1MB and we 323 * are above 1MB to keep the gdt and idt away from the bss and page 324 * tables. The idt is only used if BDE_DEBUGGER is enabled. 325 */ 326 movl $R(_end),%ecx 327 movl $R(_edata),%edi 328 subl %edi,%ecx 329 xorl %eax,%eax 330 cld 331 rep 332 stosb 333 334#if NAPM > 0 335/* 336 * XXX it's not clear that APM can live in the current environonment. 337 * Only pc-relative addressing works. 338 */ 339 call _apm_setup 340#endif 341 342 call create_pagetables 343 344#ifdef BDE_DEBUGGER 345/* 346 * Adjust as much as possible for paging before enabling paging so that the 347 * adjustments can be traced. 348 */ 349 call bdb_prepare_paging 350#endif 351 352/* Now enable paging */ 353 movl R(_IdlePTD), %eax 354 movl %eax,%cr3 /* load ptd addr into mmu */ 355 movl %cr0,%eax /* get control word */ 356 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 357 movl %eax,%cr0 /* and let's page NOW! */ 358 359#ifdef BDE_DEBUGGER 360/* 361 * Complete the adjustments for paging so that we can keep tracing through 362 * initi386() after the low (physical) addresses for the gdt and idt become 363 * invalid. 364 */ 365 call bdb_commit_paging 366#endif 367 368 pushl $begin /* jump to high virtualized address */ 369 ret 370 371/* now running relocated at KERNBASE where the system is linked to run */ 372begin: 373 /* set up bootstrap stack */ 374 movl _proc0paddr,%esp /* location of in-kernel pages */ 375 addl $UPAGES*PAGE_SIZE,%esp /* bootstrap stack end location */ 376 xorl %eax,%eax /* mark end of frames */ 377 movl %eax,%ebp 378 movl _proc0paddr,%eax 379 movl _IdlePTD, %esi 380 movl %esi,PCB_CR3(%eax) 381 382 movl physfree, %esi 383 pushl %esi /* value of first for init386(first) */ 384 call _init386 /* wire 386 chip for unix operation */ 385 popl %esi 386 387 .globl __ucodesel,__udatasel 388 389 pushl $0 /* unused */ 390 pushl __udatasel /* ss */ 391 pushl $0 /* esp - filled in by execve() */ 392 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 393 pushl __ucodesel /* cs */ 394 pushl $0 /* eip - filled in by execve() */ 395 subl $(12*4),%esp /* space for rest of registers */ 396 397 pushl %esp /* call main with frame pointer */ 398 call _main /* autoconfiguration, mountroot etc */ 399 400 hlt /* never returns to here */ 401 402/* 403 * When starting init, call this to configure the process for user 404 * mode. This will be inherited by other processes. 405 */ 406NON_GPROF_ENTRY(prepare_usermode) 407 /* 408 * Now we've run main() and determined what cpu-type we are, we can 409 * enable write protection and alignment checking on i486 cpus and 410 * above. 411 */ 412#if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU) 413 cmpl $CPUCLASS_386,_cpu_class 414 je 1f 415 movl %cr0,%eax /* get control word */ 416 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 417 movl %eax,%cr0 /* and do it */ 4181: 419#endif 420 /* 421 * on return from main(), we are process 1 422 * set up address space and stack so that we can 'return' to user mode 423 */ 424 movl __ucodesel,%eax 425 movl __udatasel,%ecx 426 427#if 0 428 movl %cx,%ds 429#endif 430 movl %cx,%es 431 movl %ax,%fs /* double map cs to fs */ 432 movl %cx,%gs /* and ds to gs */ 433 ret /* goto user! */ 434 435 436#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 437 438/* 439 * Signal trampoline, copied to top of user stack 440 */ 441NON_GPROF_ENTRY(sigcode) 442 call SIGF_HANDLER(%esp) 443 lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 444 /* copy at 8(%esp)) */ 445 pushl %eax 446 pushl %eax /* junk to fake return address */ 447 movl $SYS_sigreturn,%eax /* sigreturn() */ 448 LCALL(0x7,0) /* enter kernel with args on stack */ 449 hlt /* never gets here */ 450 ALIGN_TEXT 451_esigcode: 452 453 .data 454 .globl _szsigcode 455_szsigcode: 456 .long _esigcode-_sigcode 457 .text 458 459/********************************************************************** 460 * 461 * Recover the bootinfo passed to us from the boot program 462 * 463 */ 464recover_bootinfo: 465 /* 466 * This code is called in different ways depending on what loaded 467 * and started the kernel. This is used to detect how we get the 468 * arguments from the other code and what we do with them. 469 * 470 * Old disk boot blocks: 471 * (*btext)(howto, bootdev, cyloffset, esym); 472 * [return address == 0, and can NOT be returned to] 473 * [cyloffset was not supported by the FreeBSD boot code 474 * and always passed in as 0] 475 * [esym is also known as total in the boot code, and 476 * was never properly supported by the FreeBSD boot code] 477 * 478 * Old diskless netboot code: 479 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 480 * [return address != 0, and can NOT be returned to] 481 * If we are being booted by this code it will NOT work, 482 * so we are just going to halt if we find this case. 483 * 484 * New uniform boot code: 485 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 486 * [return address != 0, and can be returned to] 487 * 488 * There may seem to be a lot of wasted arguments in here, but 489 * that is so the newer boot code can still load very old kernels 490 * and old boot code can load new kernels. 491 */ 492 493 /* 494 * The old style disk boot blocks fake a frame on the stack and 495 * did an lret to get here. The frame on the stack has a return 496 * address of 0. 497 */ 498 cmpl $0,4(%ebp) 499 je olddiskboot 500 501 /* 502 * We have some form of return address, so this is either the 503 * old diskless netboot code, or the new uniform code. That can 504 * be detected by looking at the 5th argument, if it is 0 505 * we are being booted by the new uniform boot code. 506 */ 507 cmpl $0,24(%ebp) 508 je newboot 509 510 /* 511 * Seems we have been loaded by the old diskless boot code, we 512 * don't stand a chance of running as the diskless structure 513 * changed considerably between the two, so just halt. 514 */ 515 hlt 516 517 /* 518 * We have been loaded by the new uniform boot code. 519 * Let's check the bootinfo version, and if we do not understand 520 * it we return to the loader with a status of 1 to indicate this error 521 */ 522newboot: 523 movl 28(%ebp),%ebx /* &bootinfo.version */ 524 movl BI_VERSION(%ebx),%eax 525 cmpl $1,%eax /* We only understand version 1 */ 526 je 1f 527 movl $1,%eax /* Return status */ 528 leave 529 /* 530 * XXX this returns to our caller's caller (as is required) since 531 * we didn't set up a frame and our caller did. 532 */ 533 ret 534 5351: 536 /* 537 * If we have a kernelname copy it in 538 */ 539 movl BI_KERNELNAME(%ebx),%esi 540 cmpl $0,%esi 541 je 2f /* No kernelname */ 542 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 543 movl $R(_kernelname),%edi 544 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 545 je 1f 546 movb $'/',(%edi) 547 incl %edi 548 decl %ecx 5491: 550 cld 551 rep 552 movsb 553 5542: 555 /* 556 * Determine the size of the boot loader's copy of the bootinfo 557 * struct. This is impossible to do properly because old versions 558 * of the struct don't contain a size field and there are 2 old 559 * versions with the same version number. 560 */ 561 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 562 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 563 je got_bi_size /* no, sizeless version */ 564 movl BI_SIZE(%ebx),%ecx 565got_bi_size: 566 567 /* 568 * Copy the common part of the bootinfo struct 569 */ 570 movl %ebx,%esi 571 movl $R(_bootinfo),%edi 572 cmpl $BOOTINFO_SIZE,%ecx 573 jbe got_common_bi_size 574 movl $BOOTINFO_SIZE,%ecx 575got_common_bi_size: 576 cld 577 rep 578 movsb 579 580#ifdef NFS 581#ifndef BOOTP_NFSV3 582 /* 583 * If we have a nfs_diskless structure copy it in 584 */ 585 movl BI_NFS_DISKLESS(%ebx),%esi 586 cmpl $0,%esi 587 je olddiskboot 588 movl $R(_nfs_diskless),%edi 589 movl $NFSDISKLESS_SIZE,%ecx 590 cld 591 rep 592 movsb 593 movl $R(_nfs_diskless_valid),%edi 594 movl $1,(%edi) 595#endif 596#endif 597 598 /* 599 * The old style disk boot. 600 * (*btext)(howto, bootdev, cyloffset, esym); 601 * Note that the newer boot code just falls into here to pick 602 * up howto and bootdev, cyloffset and esym are no longer used 603 */ 604olddiskboot: 605 movl 8(%ebp),%eax 606 movl %eax,R(_boothowto) 607 movl 12(%ebp),%eax 608 movl %eax,R(_bootdev) 609 610#if defined(USERCONFIG_BOOT) && defined(USERCONFIG) 611#ifdef PC98 612 movl $0x90200, %esi 613#else 614 movl $0x10200, %esi 615#endif 616 movl $R(_userconfig_from_boot),%edi 617 movl $512,%ecx 618 cld 619 rep 620 movsb 621#endif /* USERCONFIG_BOOT */ 622 623 ret 624 625 626/********************************************************************** 627 * 628 * Identify the CPU and initialize anything special about it 629 * 630 */ 631identify_cpu: 632 633 /* Try to toggle alignment check flag; does not exist on 386. */ 634 pushfl 635 popl %eax 636 movl %eax,%ecx 637 orl $PSL_AC,%eax 638 pushl %eax 639 popfl 640 pushfl 641 popl %eax 642 xorl %ecx,%eax 643 andl $PSL_AC,%eax 644 pushl %ecx 645 popfl 646 647 testl %eax,%eax 648 jnz try486 649 650 /* NexGen CPU does not have aligment check flag. */ 651 pushfl 652 movl $0x5555, %eax 653 xorl %edx, %edx 654 movl $2, %ecx 655 clc 656 divl %ecx 657 jz trynexgen 658 popfl 659 movl $CPU_386,R(_cpu) 660 jmp 3f 661 662trynexgen: 663 movl $CPU_NX586,R(_cpu) 664 movl $0x4778654e,R(_cpu_vendor) # store vendor string 665 movl $0x72446e65,R(_cpu_vendor+4) 666 movl $0x6e657669,R(_cpu_vendor+8) 667 movl $0,R(_cpu_vendor+12) 668 jmp 3f 669 670try486: /* Try to toggle identification flag; does not exist on early 486s. */ 671 pushfl 672 popl %eax 673 movl %eax,%ecx 674 xorl $PSL_ID,%eax 675 pushl %eax 676 popfl 677 pushfl 678 popl %eax 679 xorl %ecx,%eax 680 andl $PSL_ID,%eax 681 pushl %ecx 682 popfl 683 684 testl %eax,%eax 685 jnz trycpuid 686 movl $CPU_486,R(_cpu) 687 688 /* 689 * Check Cyrix CPU 690 * Cyrix CPUs do not change the undefined flags following 691 * execution of the divide instruction which divides 5 by 2. 692 * 693 * Note: CPUID is enabled on M2, so it passes another way. 694 */ 695 pushfl 696 movl $0x5555, %eax 697 xorl %edx, %edx 698 movl $2, %ecx 699 clc 700 divl %ecx 701 jnc trycyrix 702 popfl 703 jmp 3f /* You may use Intel CPU. */ 704 705trycyrix: 706 popfl 707 /* 708 * IBM Bluelighting CPU also doesn't change the undefined flags. 709 * Because IBM doesn't disclose the information for Bluelighting 710 * CPU, we couldn't distinguish it from Cyrix's (including IBM 711 * brand of Cyrix CPUs). 712 */ 713 movl $0x69727943,R(_cpu_vendor) # store vendor string 714 movl $0x736e4978,R(_cpu_vendor+4) 715 movl $0x64616574,R(_cpu_vendor+8) 716 jmp 3f 717 718trycpuid: /* Use the `cpuid' instruction. */ 719 xorl %eax,%eax 720 .byte 0x0f,0xa2 # cpuid 0 721 movl %eax,R(_cpu_high) # highest capability 722 movl %ebx,R(_cpu_vendor) # store vendor string 723 movl %edx,R(_cpu_vendor+4) 724 movl %ecx,R(_cpu_vendor+8) 725 movb $0,R(_cpu_vendor+12) 726 727 movl $1,%eax 728 .byte 0x0f,0xa2 # cpuid 1 729 movl %eax,R(_cpu_id) # store cpu_id 730 movl %edx,R(_cpu_feature) # store cpu_feature 731 rorl $8,%eax # extract family type 732 andl $15,%eax 733 cmpl $5,%eax 734 jae 1f 735 736 /* less than Pentium; must be 486 */ 737 movl $CPU_486,R(_cpu) 738 jmp 3f 7391: 740 /* a Pentium? */ 741 cmpl $5,%eax 742 jne 2f 743 movl $CPU_586,R(_cpu) 744 jmp 3f 7452: 746 /* Greater than Pentium...call it a Pentium Pro */ 747 movl $CPU_686,R(_cpu) 7483: 749 ret 750 751 752/********************************************************************** 753 * 754 * Create the first page directory and its page tables. 755 * 756 */ 757 758create_pagetables: 759 760 testl $CPUID_PGE, R(_cpu_feature) 761 jz 1f 762 movl %cr4, %eax 763 orl $CR4_PGE, %eax 764 movl %eax, %cr4 7651: 766 767/* Find end of kernel image (rounded up to a page boundary). */ 768 movl $R(_end),%esi 769 770/* include symbols in "kernel image" if they are loaded and useful */ 771#ifdef DDB 772 movl R(_bootinfo+BI_ESYMTAB),%edi 773 testl %edi,%edi 774 je over_symalloc 775 movl %edi,%esi 776 movl $KERNBASE,%edi 777 addl %edi,R(_bootinfo+BI_SYMTAB) 778 addl %edi,R(_bootinfo+BI_ESYMTAB) 779over_symalloc: 780#endif 781 782 addl $PAGE_MASK,%esi 783 andl $~PAGE_MASK,%esi 784 movl %esi,R(_KERNend) /* save end of kernel */ 785 movl %esi,R(physfree) /* next free page is at end of kernel */ 786 787/* Allocate Kernel Page Tables */ 788 ALLOCPAGES(NKPT) 789 movl %esi,R(_KPTphys) 790 791/* Allocate Page Table Directory */ 792 ALLOCPAGES(1) 793 movl %esi,R(_IdlePTD) 794 795/* Allocate UPAGES */ 796 ALLOCPAGES(UPAGES) 797 movl %esi,R(p0upa) 798 addl $KERNBASE, %esi 799 movl %esi, R(_proc0paddr) 800 801#ifdef SMP 802/* Allocate cpu0's private data page */ 803 ALLOCPAGES(1) 804 movl %esi,R(cpu0pp) 805 addl $KERNBASE, %esi 806 movl %esi, R(_cpu0prvpage) /* relocated to KVM space */ 807 808/* Allocate cpu0's private page table for mapping priv page, apic, etc */ 809 ALLOCPAGES(1) 810 movl %esi,R(cpu0pt) 811 addl $KERNBASE, %esi 812 movl %esi, R(_cpu0prvpt) /* relocated to KVM space */ 813#endif /* SMP */ 814 815/* Map read-only from zero to the end of the kernel text section */ 816 xorl %eax, %eax 817#ifdef BDE_DEBUGGER 818/* If the debugger is present, actually map everything read-write. */ 819 cmpl $0,R(_bdb_exists) 820 jne map_read_write 821#endif 822 xorl %edx,%edx 823 testl $CPUID_PGE, R(_cpu_feature) 824 jz 2f 825 orl $PG_G,%edx 826 8272: movl $R(_etext),%ecx 828 addl $PAGE_MASK,%ecx 829 shrl $PAGE_SHIFT,%ecx 830 fillkptphys(%edx) 831 832/* Map read-write, data, bss and symbols */ 833 movl $R(_etext),%eax 834 addl $PAGE_MASK, %eax 835 andl $~PAGE_MASK, %eax 836map_read_write: 837 movl $PG_RW,%edx 838 testl $CPUID_PGE, R(_cpu_feature) 839 jz 1f 840 orl $PG_G,%edx 841 8421: movl R(_KERNend),%ecx 843 subl %eax,%ecx 844 shrl $PAGE_SHIFT,%ecx 845 fillkptphys(%edx) 846 847/* Map page directory. */ 848 movl R(_IdlePTD), %eax 849 movl $1, %ecx 850 fillkptphys($PG_RW) 851 852/* Map proc0's UPAGES in the physical way ... */ 853 movl R(p0upa), %eax 854 movl $UPAGES, %ecx 855 fillkptphys($PG_RW) 856 857/* Map ISA hole */ 858 movl $ISA_HOLE_START, %eax 859 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 860 fillkptphys($PG_RW) 861 862#ifdef SMP 863/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 864 movl R(cpu0pp), %eax 865 movl $1, %ecx 866 fillkptphys($PG_RW) 867 868/* Map cpu0's private page table into global kmem FWIW */ 869 movl R(cpu0pt), %eax 870 movl $1, %ecx 871 fillkptphys($PG_RW) 872 873/* Map the private page into the private page table into private space */ 874 movl R(cpu0pp), %eax 875 movl $0, %ebx /* pte offset = 0 */ 876 movl $1, %ecx /* one private page coming right up */ 877 fillkpt(R(cpu0pt), $PG_RW) 878 879/* Map the page table page into private space */ 880 movl R(cpu0pt), %eax 881 movl $1, %ebx /* pte offset = 1 */ 882 movl $1, %ecx /* one private pt coming right up */ 883 fillkpt(R(cpu0pt), $PG_RW) 884 885/* ... and put the page table table in the pde. */ 886 movl R(cpu0pt), %eax 887 movl $MPPTDI, %ebx 888 movl $1, %ecx 889 fillkpt(R(_IdlePTD), $PG_RW) 890#endif /* SMP */ 891 892/* install a pde for temporary double map of bottom of VA */ 893 movl R(_KPTphys), %eax 894 xorl %ebx, %ebx 895 movl $1, %ecx 896 fillkpt(R(_IdlePTD), $PG_RW) 897 898/* install pde's for pt's */ 899 movl R(_KPTphys), %eax 900 movl $KPTDI, %ebx 901 movl $NKPT, %ecx 902 fillkpt(R(_IdlePTD), $PG_RW) 903 904/* install a pde recursively mapping page directory as a page table */ 905 movl R(_IdlePTD), %eax 906 movl $PTDPTDI, %ebx 907 movl $1,%ecx 908 fillkpt(R(_IdlePTD), $PG_RW) 909 910 ret 911 912#ifdef BDE_DEBUGGER 913bdb_prepare_paging: 914 cmpl $0,R(_bdb_exists) 915 je bdb_prepare_paging_exit 916 917 subl $6,%esp 918 919 /* 920 * Copy and convert debugger entries from the bootstrap gdt and idt 921 * to the kernel gdt and idt. Everything is still in low memory. 922 * Tracing continues to work after paging is enabled because the 923 * low memory addresses remain valid until everything is relocated. 924 * However, tracing through the setidt() that initializes the trace 925 * trap will crash. 926 */ 927 sgdt (%esp) 928 movl 2(%esp),%esi /* base address of bootstrap gdt */ 929 movl $R(_gdt),%edi 930 movl %edi,2(%esp) /* prepare to load kernel gdt */ 931 movl $8*18/4,%ecx 932 cld 933 rep /* copy gdt */ 934 movsl 935 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 936 movb $0x92,-8+5(%edi) 937 lgdt (%esp) 938 939 sidt (%esp) 940 movl 2(%esp),%esi /* base address of current idt */ 941 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 942 movw 8(%esi),%ax 943 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 944 movl 8+2(%esi),%eax 945 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 946 movl 24+4(%esi),%eax /* same for bpt descriptor */ 947 movw 24(%esi),%ax 948 movl %eax,R(bdb_bpt_ljmp+1) 949 movl 24+2(%esi),%eax 950 movw %ax,R(bdb_bpt_ljmp+5) 951 movl $R(_idt),%edi 952 movl %edi,2(%esp) /* prepare to load kernel idt */ 953 movl $8*4/4,%ecx 954 cld 955 rep /* copy idt */ 956 movsl 957 lidt (%esp) 958 959 addl $6,%esp 960 961bdb_prepare_paging_exit: 962 ret 963 964/* Relocate debugger gdt entries and gdt and idt pointers. */ 965bdb_commit_paging: 966 cmpl $0,_bdb_exists 967 je bdb_commit_paging_exit 968 969 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 970 movl $9,%ecx 971reloc_gdt: 972 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 973 addl $8,%eax /* now KERNBASE>>24 */ 974 loop reloc_gdt 975 976 subl $6,%esp 977 sgdt (%esp) 978 addl $KERNBASE,2(%esp) 979 lgdt (%esp) 980 sidt (%esp) 981 addl $KERNBASE,2(%esp) 982 lidt (%esp) 983 addl $6,%esp 984 985 int $3 986 987bdb_commit_paging_exit: 988 ret 989 990#endif /* BDE_DEBUGGER */ 991