locore.s revision 82307
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 * $FreeBSD: head/sys/i386/i386/locore.s 82307 2001-08-25 01:16:47Z julian $ 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 "opt_bootp.h" 47#include "opt_nfsroot.h" 48 49#include <sys/syscall.h> 50#include <sys/reboot.h> 51 52#include <machine/asmacros.h> 53#include <machine/cputypes.h> 54#include <machine/psl.h> 55#include <machine/pmap.h> 56#include <machine/specialreg.h> 57 58#include "assym.s" 59 60#ifdef __AOUT__ 61#define etext _etext 62#define edata _edata 63#define end _end 64#endif 65 66/* 67 * XXX 68 * 69 * Note: This version greatly munged to avoid various assembler errors 70 * that may be fixed in newer versions of gas. Perhaps newer versions 71 * will have more pleasant appearance. 72 */ 73 74/* 75 * PTmap is recursive pagemap at top of virtual address space. 76 * Within PTmap, the page directory can be found (third indirection). 77 * 78 * NOTE: PTDpde, PTmap, and PTD are being defined as address symbols. 79 * In C you access them directly, and not with a '*'. Storage is not being 80 * allocated. They will magically address teh correct locations in KVM 81 * whach C will treat as normal variables of the type they are defined in in 82 * machine/pmap.h, i.e. PTDpde = XX ; to set a PDE entry, NOT *PTDpde = XX; 83 */ 84 .globl PTmap,PTD,PTDpde 85 .set PTmap,(PTDPTDI << PDRSHIFT) 86 .set PTD,PTmap + (PTDPTDI * PAGE_SIZE) 87 .set PTDpde,PTD + (PTDPTDI * PDESIZE) 88 89/* 90 * APTmap, APTD is the alternate recursive pagemap. 91 * It's used when modifying another process's page tables. 92 * See the note above. It is true here as well. 93 */ 94 .globl APTmap,APTD,APTDpde 95 .set APTmap,APTDPTDI << PDRSHIFT 96 .set APTD,APTmap + (APTDPTDI * PAGE_SIZE) 97 .set APTDpde,PTD + (APTDPTDI * PDESIZE) 98 99#ifdef SMP 100/* 101 * Define layout of per-cpu address space. 102 * This is "constructed" in locore.s on the BSP and in mp_machdep.c 103 * for each AP. DO NOT REORDER THESE WITHOUT UPDATING THE REST! 104 */ 105 .globl SMP_prvspace, lapic 106 .set SMP_prvspace,(MPPTDI << PDRSHIFT) 107 .set lapic,SMP_prvspace + (NPTEPG-1) * PAGE_SIZE 108#endif /* SMP */ 109 110/* 111 * Compiled KERNBASE location 112 */ 113 .globl kernbase 114 .set kernbase,KERNBASE 115 116/* 117 * Globals 118 */ 119 .data 120 ALIGN_DATA /* just to be sure */ 121 122 .globl HIDENAME(tmpstk) 123 .space 0x2000 /* space for tmpstk - temporary stack */ 124HIDENAME(tmpstk): 125 126 .globl boothowto,bootdev 127 128 .globl cpu,cpu_vendor,cpu_id,bootinfo 129 .globl cpu_high, cpu_feature 130 131cpu: .long 0 /* are we 386, 386sx, or 486 */ 132cpu_id: .long 0 /* stepping ID */ 133cpu_high: .long 0 /* highest arg to CPUID */ 134cpu_feature: .long 0 /* features */ 135cpu_vendor: .space 20 /* CPU origin code */ 136bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 137 138KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 139physfree: .long 0 /* phys addr of next free page */ 140 141#ifdef SMP 142 .globl cpu0prvpage 143cpu0pp: .long 0 /* phys addr cpu0 private pg */ 144cpu0prvpage: .long 0 /* relocated version */ 145 146 .globl SMPpt 147SMPptpa: .long 0 /* phys addr SMP page table */ 148SMPpt: .long 0 /* relocated version */ 149#endif /* SMP */ 150 151 .globl IdlePTD 152IdlePTD: .long 0 /* phys addr of kernel PTD */ 153 154#ifdef SMP 155 .globl KPTphys 156#endif 157KPTphys: .long 0 /* phys addr of kernel page tables */ 158 159 .globl proc0paddr 160proc0paddr: .long 0 /* address of proc 0 address space */ 161p0upa: .long 0 /* phys addr of proc0's UPAGES */ 162 163vm86phystk: .long 0 /* PA of vm86/bios stack */ 164 165 .globl vm86paddr, vm86pa 166vm86paddr: .long 0 /* address of vm86 region */ 167vm86pa: .long 0 /* phys addr of vm86 region */ 168 169#ifdef BDE_DEBUGGER 170 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 171_bdb_exists: .long 0 172#endif 173 174#ifdef PC98 175 .globl pc98_system_parameter 176pc98_system_parameter: 177 .space 0x240 178#endif 179 180/********************************************************************** 181 * 182 * Some handy macros 183 * 184 */ 185 186#define R(foo) ((foo)-KERNBASE) 187 188#define ALLOCPAGES(foo) \ 189 movl R(physfree), %esi ; \ 190 movl $((foo)*PAGE_SIZE), %eax ; \ 191 addl %esi, %eax ; \ 192 movl %eax, R(physfree) ; \ 193 movl %esi, %edi ; \ 194 movl $((foo)*PAGE_SIZE),%ecx ; \ 195 xorl %eax,%eax ; \ 196 cld ; \ 197 rep ; \ 198 stosb 199 200/* 201 * fillkpt 202 * eax = page frame address 203 * ebx = index into page table 204 * ecx = how many pages to map 205 * base = base address of page dir/table 206 * prot = protection bits 207 */ 208#define fillkpt(base, prot) \ 209 shll $2,%ebx ; \ 210 addl base,%ebx ; \ 211 orl $PG_V,%eax ; \ 212 orl prot,%eax ; \ 2131: movl %eax,(%ebx) ; \ 214 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 215 addl $4,%ebx ; /* next pte */ \ 216 loop 1b 217 218/* 219 * fillkptphys(prot) 220 * eax = physical address 221 * ecx = how many pages to map 222 * prot = protection bits 223 */ 224#define fillkptphys(prot) \ 225 movl %eax, %ebx ; \ 226 shrl $PAGE_SHIFT, %ebx ; \ 227 fillkpt(R(KPTphys), prot) 228 229 .text 230/********************************************************************** 231 * 232 * This is where the bootblocks start us, set the ball rolling... 233 * 234 */ 235NON_GPROF_ENTRY(btext) 236 237#ifdef PC98 238 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 239 movl $0xa1400,%esi 240 movl $R(pc98_system_parameter),%edi 241 movl $0x0240,%ecx 242 cld 243 rep 244 movsb 245#else /* IBM-PC */ 246#ifdef BDE_DEBUGGER 247#ifdef BIOS_STEALS_3K 248 cmpl $0x0375c339,0x95504 249#else 250 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 251#endif 252 jne 1f 253 movb $1,R(_bdb_exists) 2541: 255#endif 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 /* pc98_machine_type & M_EPSON_PC98 */ 288 testb $0x02,R(pc98_system_parameter)+220 289 jz 3f 290 /* epson_machine_id <= 0x0b */ 291 cmpb $0x0b,R(pc98_system_parameter)+224 292 ja 3f 293 294 /* count up memory */ 295 movl $0x100000,%eax /* next, talley remaining memory */ 296 movl $0xFFF-0x100,%ecx 2971: movl 0(%eax),%ebx /* save location to check */ 298 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 299 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 300 jne 2f 301 movl %ebx,0(%eax) /* restore memory */ 302 addl $PAGE_SIZE,%eax 303 loop 1b 3042: subl $0x100000,%eax 305 shrl $17,%eax 306 movb %al,R(pc98_system_parameter)+1 3073: 308 309 movw R(pc98_system_parameter+0x86),%ax 310 movw %ax,R(cpu_id) 311#endif 312 313 call identify_cpu 314 315/* clear bss */ 316/* 317 * XXX this should be done a little earlier. 318 * 319 * XXX we don't check that there is memory for our bss and page tables 320 * before using it. 321 * 322 * XXX the boot program somewhat bogusly clears the bss. We still have 323 * to do it in case we were unzipped by kzipboot. Then the boot program 324 * only clears kzipboot's bss. 325 * 326 * XXX the gdt and idt are still somewhere in the boot program. We 327 * depend on the convention that the boot program is below 1MB and we 328 * are above 1MB to keep the gdt and idt away from the bss and page 329 * tables. The idt is only used if BDE_DEBUGGER is enabled. 330 */ 331 movl $R(end),%ecx 332 movl $R(edata),%edi 333 subl %edi,%ecx 334 xorl %eax,%eax 335 cld 336 rep 337 stosb 338 339 call create_pagetables 340 341/* 342 * If the CPU has support for VME, turn it on. 343 */ 344 testl $CPUID_VME, R(cpu_feature) 345 jz 1f 346 movl %cr4, %eax 347 orl $CR4_VME, %eax 348 movl %eax, %cr4 3491: 350 351#ifdef BDE_DEBUGGER 352/* 353 * Adjust as much as possible for paging before enabling paging so that the 354 * adjustments can be traced. 355 */ 356 call bdb_prepare_paging 357#endif 358 359/* Now enable paging */ 360 movl R(IdlePTD), %eax 361 movl %eax,%cr3 /* load ptd addr into mmu */ 362 movl %cr0,%eax /* get control word */ 363 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 364 movl %eax,%cr0 /* and let's page NOW! */ 365 366#ifdef BDE_DEBUGGER 367/* 368 * Complete the adjustments for paging so that we can keep tracing through 369 * initi386() after the low (physical) addresses for the gdt and idt become 370 * invalid. 371 */ 372 call bdb_commit_paging 373#endif 374 375 pushl $begin /* jump to high virtualized address */ 376 ret 377 378/* now running relocated at KERNBASE where the system is linked to run */ 379begin: 380 /* set up bootstrap stack */ 381 movl proc0paddr,%eax /* location of in-kernel pages */ 382 leal UPAGES*PAGE_SIZE(%eax),%esp /* bootstrap stack end location */ 383 384 xorl %ebp,%ebp /* mark end of frames */ 385 386 movl IdlePTD,%esi 387 movl %esi,PCB_CR3(%eax) 388 389 testl $CPUID_PGE, R(cpu_feature) 390 jz 1f 391 movl %cr4, %eax 392 orl $CR4_PGE, %eax 393 movl %eax, %cr4 3941: 395 pushl physfree /* value of first for init386(first) */ 396 call init386 /* wire 386 chip for unix operation */ 397 398 /* 399 * Clean up the stack in a way that db_numargs() understands, so 400 * that backtraces in ddb don't underrun the stack. Traps for 401 * inaccessible memory are more fatal than usual this early. 402 */ 403 addl $4,%esp 404 405 call mi_startup /* autoconfiguration, mountroot etc */ 406 /* NOTREACHED */ 407 addl $0,%esp /* for db_numargs() again */ 408 409/* 410 * Signal trampoline, copied to top of user stack 411 */ 412NON_GPROF_ENTRY(sigcode) 413 call *SIGF_HANDLER(%esp) /* call signal handler */ 414 lea SIGF_UC(%esp),%eax /* get ucontext_t */ 415 pushl %eax 416 testl $PSL_VM,UC_EFLAGS(%eax) 417 jne 9f 418 movl UC_GS(%eax),%gs /* restore %gs */ 4199: 420 movl $SYS_sigreturn,%eax 421 pushl %eax /* junk to fake return addr. */ 422 int $0x80 /* enter kernel with args */ 4230: jmp 0b 424 425 ALIGN_TEXT 426osigcode: 427 call *SIGF_HANDLER(%esp) /* call signal handler */ 428 lea SIGF_SC(%esp),%eax /* get sigcontext */ 429 pushl %eax 430 testl $PSL_VM,SC_PS(%eax) 431 jne 9f 432 movl SC_GS(%eax),%gs /* restore %gs */ 4339: 434 movl $0x01d516,SC_TRAPNO(%eax) /* magic: 0ldSiG */ 435 movl $SYS_sigreturn,%eax 436 pushl %eax /* junk to fake return addr. */ 437 int $0x80 /* enter kernel with args */ 4380: jmp 0b 439 440 ALIGN_TEXT 441esigcode: 442 443 .data 444 .globl szsigcode, szosigcode 445szsigcode: 446 .long esigcode-sigcode 447szosigcode: 448 .long esigcode-osigcode 449 .text 450 451/********************************************************************** 452 * 453 * Recover the bootinfo passed to us from the boot program 454 * 455 */ 456recover_bootinfo: 457 /* 458 * This code is called in different ways depending on what loaded 459 * and started the kernel. This is used to detect how we get the 460 * arguments from the other code and what we do with them. 461 * 462 * Old disk boot blocks: 463 * (*btext)(howto, bootdev, cyloffset, esym); 464 * [return address == 0, and can NOT be returned to] 465 * [cyloffset was not supported by the FreeBSD boot code 466 * and always passed in as 0] 467 * [esym is also known as total in the boot code, and 468 * was never properly supported by the FreeBSD boot code] 469 * 470 * Old diskless netboot code: 471 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 472 * [return address != 0, and can NOT be returned to] 473 * If we are being booted by this code it will NOT work, 474 * so we are just going to halt if we find this case. 475 * 476 * New uniform boot code: 477 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 478 * [return address != 0, and can be returned to] 479 * 480 * There may seem to be a lot of wasted arguments in here, but 481 * that is so the newer boot code can still load very old kernels 482 * and old boot code can load new kernels. 483 */ 484 485 /* 486 * The old style disk boot blocks fake a frame on the stack and 487 * did an lret to get here. The frame on the stack has a return 488 * address of 0. 489 */ 490 cmpl $0,4(%ebp) 491 je olddiskboot 492 493 /* 494 * We have some form of return address, so this is either the 495 * old diskless netboot code, or the new uniform code. That can 496 * be detected by looking at the 5th argument, if it is 0 497 * we are being booted by the new uniform boot code. 498 */ 499 cmpl $0,24(%ebp) 500 je newboot 501 502 /* 503 * Seems we have been loaded by the old diskless boot code, we 504 * don't stand a chance of running as the diskless structure 505 * changed considerably between the two, so just halt. 506 */ 507 hlt 508 509 /* 510 * We have been loaded by the new uniform boot code. 511 * Let's check the bootinfo version, and if we do not understand 512 * it we return to the loader with a status of 1 to indicate this error 513 */ 514newboot: 515 movl 28(%ebp),%ebx /* &bootinfo.version */ 516 movl BI_VERSION(%ebx),%eax 517 cmpl $1,%eax /* We only understand version 1 */ 518 je 1f 519 movl $1,%eax /* Return status */ 520 leave 521 /* 522 * XXX this returns to our caller's caller (as is required) since 523 * we didn't set up a frame and our caller did. 524 */ 525 ret 526 5271: 528 /* 529 * If we have a kernelname copy it in 530 */ 531 movl BI_KERNELNAME(%ebx),%esi 532 cmpl $0,%esi 533 je 2f /* No kernelname */ 534 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 535 movl $R(kernelname),%edi 536 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 537 je 1f 538 movb $'/',(%edi) 539 incl %edi 540 decl %ecx 5411: 542 cld 543 rep 544 movsb 545 5462: 547 /* 548 * Determine the size of the boot loader's copy of the bootinfo 549 * struct. This is impossible to do properly because old versions 550 * of the struct don't contain a size field and there are 2 old 551 * versions with the same version number. 552 */ 553 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 554 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 555 je got_bi_size /* no, sizeless version */ 556 movl BI_SIZE(%ebx),%ecx 557got_bi_size: 558 559 /* 560 * Copy the common part of the bootinfo struct 561 */ 562 movl %ebx,%esi 563 movl $R(bootinfo),%edi 564 cmpl $BOOTINFO_SIZE,%ecx 565 jbe got_common_bi_size 566 movl $BOOTINFO_SIZE,%ecx 567got_common_bi_size: 568 cld 569 rep 570 movsb 571 572#ifdef NFS_ROOT 573#ifndef BOOTP_NFSV3 574 /* 575 * If we have a nfs_diskless structure copy it in 576 */ 577 movl BI_NFS_DISKLESS(%ebx),%esi 578 cmpl $0,%esi 579 je olddiskboot 580 movl $R(nfs_diskless),%edi 581 movl $NFSDISKLESS_SIZE,%ecx 582 cld 583 rep 584 movsb 585 movl $R(nfs_diskless_valid),%edi 586 movl $1,(%edi) 587#endif 588#endif 589 590 /* 591 * The old style disk boot. 592 * (*btext)(howto, bootdev, cyloffset, esym); 593 * Note that the newer boot code just falls into here to pick 594 * up howto and bootdev, cyloffset and esym are no longer used 595 */ 596olddiskboot: 597 movl 8(%ebp),%eax 598 movl %eax,R(boothowto) 599 movl 12(%ebp),%eax 600 movl %eax,R(bootdev) 601 602 ret 603 604 605/********************************************************************** 606 * 607 * Identify the CPU and initialize anything special about it 608 * 609 */ 610identify_cpu: 611 612 /* Try to toggle alignment check flag; does not exist on 386. */ 613 pushfl 614 popl %eax 615 movl %eax,%ecx 616 orl $PSL_AC,%eax 617 pushl %eax 618 popfl 619 pushfl 620 popl %eax 621 xorl %ecx,%eax 622 andl $PSL_AC,%eax 623 pushl %ecx 624 popfl 625 626 testl %eax,%eax 627 jnz try486 628 629 /* NexGen CPU does not have aligment check flag. */ 630 pushfl 631 movl $0x5555, %eax 632 xorl %edx, %edx 633 movl $2, %ecx 634 clc 635 divl %ecx 636 jz trynexgen 637 popfl 638 movl $CPU_386,R(cpu) 639 jmp 3f 640 641trynexgen: 642 popfl 643 movl $CPU_NX586,R(cpu) 644 movl $0x4778654e,R(cpu_vendor) # store vendor string 645 movl $0x72446e65,R(cpu_vendor+4) 646 movl $0x6e657669,R(cpu_vendor+8) 647 movl $0,R(cpu_vendor+12) 648 jmp 3f 649 650try486: /* Try to toggle identification flag; does not exist on early 486s. */ 651 pushfl 652 popl %eax 653 movl %eax,%ecx 654 xorl $PSL_ID,%eax 655 pushl %eax 656 popfl 657 pushfl 658 popl %eax 659 xorl %ecx,%eax 660 andl $PSL_ID,%eax 661 pushl %ecx 662 popfl 663 664 testl %eax,%eax 665 jnz trycpuid 666 movl $CPU_486,R(cpu) 667 668 /* 669 * Check Cyrix CPU 670 * Cyrix CPUs do not change the undefined flags following 671 * execution of the divide instruction which divides 5 by 2. 672 * 673 * Note: CPUID is enabled on M2, so it passes another way. 674 */ 675 pushfl 676 movl $0x5555, %eax 677 xorl %edx, %edx 678 movl $2, %ecx 679 clc 680 divl %ecx 681 jnc trycyrix 682 popfl 683 jmp 3f /* You may use Intel CPU. */ 684 685trycyrix: 686 popfl 687 /* 688 * IBM Bluelighting CPU also doesn't change the undefined flags. 689 * Because IBM doesn't disclose the information for Bluelighting 690 * CPU, we couldn't distinguish it from Cyrix's (including IBM 691 * brand of Cyrix CPUs). 692 */ 693 movl $0x69727943,R(cpu_vendor) # store vendor string 694 movl $0x736e4978,R(cpu_vendor+4) 695 movl $0x64616574,R(cpu_vendor+8) 696 jmp 3f 697 698trycpuid: /* Use the `cpuid' instruction. */ 699 xorl %eax,%eax 700 cpuid # cpuid 0 701 movl %eax,R(cpu_high) # highest capability 702 movl %ebx,R(cpu_vendor) # store vendor string 703 movl %edx,R(cpu_vendor+4) 704 movl %ecx,R(cpu_vendor+8) 705 movb $0,R(cpu_vendor+12) 706 707 movl $1,%eax 708 cpuid # cpuid 1 709 movl %eax,R(cpu_id) # store cpu_id 710 movl %edx,R(cpu_feature) # store cpu_feature 711 rorl $8,%eax # extract family type 712 andl $15,%eax 713 cmpl $5,%eax 714 jae 1f 715 716 /* less than Pentium; must be 486 */ 717 movl $CPU_486,R(cpu) 718 jmp 3f 7191: 720 /* a Pentium? */ 721 cmpl $5,%eax 722 jne 2f 723 movl $CPU_586,R(cpu) 724 jmp 3f 7252: 726 /* Greater than Pentium...call it a Pentium Pro */ 727 movl $CPU_686,R(cpu) 7283: 729 ret 730 731 732/********************************************************************** 733 * 734 * Create the first page directory and its page tables. 735 * 736 */ 737 738create_pagetables: 739 740/* Find end of kernel image (rounded up to a page boundary). */ 741 movl $R(_end),%esi 742 743/* Include symbols, if any. */ 744 movl R(bootinfo+BI_ESYMTAB),%edi 745 testl %edi,%edi 746 je over_symalloc 747 movl %edi,%esi 748 movl $KERNBASE,%edi 749 addl %edi,R(bootinfo+BI_SYMTAB) 750 addl %edi,R(bootinfo+BI_ESYMTAB) 751over_symalloc: 752 753/* If we are told where the end of the kernel space is, believe it. */ 754 movl R(bootinfo+BI_KERNEND),%edi 755 testl %edi,%edi 756 je no_kernend 757 movl %edi,%esi 758no_kernend: 759 760 addl $PAGE_MASK,%esi 761 andl $~PAGE_MASK,%esi 762 movl %esi,R(KERNend) /* save end of kernel */ 763 movl %esi,R(physfree) /* next free page is at end of kernel */ 764 765/* Allocate Kernel Page Tables */ 766 ALLOCPAGES(NKPT) 767 movl %esi,R(KPTphys) 768 769/* Allocate Page Table Directory */ 770 ALLOCPAGES(1) 771 movl %esi,R(IdlePTD) 772 773/* Allocate UPAGES */ 774 ALLOCPAGES(UPAGES) 775 movl %esi,R(p0upa) 776 addl $KERNBASE, %esi 777 movl %esi, R(proc0paddr) 778 779 ALLOCPAGES(1) /* vm86/bios stack */ 780 movl %esi,R(vm86phystk) 781 782 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 783 movl %esi,R(vm86pa) 784 addl $KERNBASE, %esi 785 movl %esi, R(vm86paddr) 786 787#ifdef SMP 788/* Allocate cpu0's private data page */ 789 ALLOCPAGES(1) 790 movl %esi,R(cpu0pp) 791 addl $KERNBASE, %esi 792 movl %esi, R(cpu0prvpage) /* relocated to KVM space */ 793 794/* Allocate SMP page table page */ 795 ALLOCPAGES(1) 796 movl %esi,R(SMPptpa) 797 addl $KERNBASE, %esi 798 movl %esi, R(SMPpt) /* relocated to KVM space */ 799#endif /* SMP */ 800 801/* Map read-only from zero to the end of the kernel text section */ 802 xorl %eax, %eax 803#ifdef BDE_DEBUGGER 804/* If the debugger is present, actually map everything read-write. */ 805 cmpl $0,R(_bdb_exists) 806 jne map_read_write 807#endif 808 xorl %edx,%edx 809 810#if !defined(SMP) 811 testl $CPUID_PGE, R(cpu_feature) 812 jz 2f 813 orl $PG_G,%edx 814#endif 815 8162: movl $R(etext),%ecx 817 addl $PAGE_MASK,%ecx 818 shrl $PAGE_SHIFT,%ecx 819 fillkptphys(%edx) 820 821/* Map read-write, data, bss and symbols */ 822 movl $R(etext),%eax 823 addl $PAGE_MASK, %eax 824 andl $~PAGE_MASK, %eax 825map_read_write: 826 movl $PG_RW,%edx 827#if !defined(SMP) 828 testl $CPUID_PGE, R(cpu_feature) 829 jz 1f 830 orl $PG_G,%edx 831#endif 832 8331: movl R(KERNend),%ecx 834 subl %eax,%ecx 835 shrl $PAGE_SHIFT,%ecx 836 fillkptphys(%edx) 837 838/* Map page directory. */ 839 movl R(IdlePTD), %eax 840 movl $1, %ecx 841 fillkptphys($PG_RW) 842 843/* Map proc0's UPAGES in the physical way ... */ 844 movl R(p0upa), %eax 845 movl $UPAGES, %ecx 846 fillkptphys($PG_RW) 847 848/* Map ISA hole */ 849 movl $ISA_HOLE_START, %eax 850 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 851 fillkptphys($PG_RW) 852 853/* Map space for the vm86 region */ 854 movl R(vm86phystk), %eax 855 movl $4, %ecx 856 fillkptphys($PG_RW) 857 858/* Map page 0 into the vm86 page table */ 859 movl $0, %eax 860 movl $0, %ebx 861 movl $1, %ecx 862 fillkpt(R(vm86pa), $PG_RW|PG_U) 863 864/* ...likewise for the ISA hole */ 865 movl $ISA_HOLE_START, %eax 866 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 867 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 868 fillkpt(R(vm86pa), $PG_RW|PG_U) 869 870#ifdef SMP 871/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 872 movl R(cpu0pp), %eax 873 movl $1, %ecx 874 fillkptphys($PG_RW) 875 876/* Map SMP page table page into global kmem FWIW */ 877 movl R(SMPptpa), %eax 878 movl $1, %ecx 879 fillkptphys($PG_RW) 880 881/* Map the private page into the SMP page table */ 882 movl R(cpu0pp), %eax 883 movl $0, %ebx /* pte offset = 0 */ 884 movl $1, %ecx /* one private page coming right up */ 885 fillkpt(R(SMPptpa), $PG_RW) 886 887/* ... and put the page table table in the pde. */ 888 movl R(SMPptpa), %eax 889 movl $MPPTDI, %ebx 890 movl $1, %ecx 891 fillkpt(R(IdlePTD), $PG_RW) 892 893/* Fakeup VA for the local apic to allow early traps. */ 894 ALLOCPAGES(1) 895 movl %esi, %eax 896 movl $(NPTEPG-1), %ebx /* pte offset = NTEPG-1 */ 897 movl $1, %ecx /* one private pt coming right up */ 898 fillkpt(R(SMPptpa), $PG_RW) 899#endif /* SMP */ 900 901/* install a pde for temporary double map of bottom of VA */ 902 movl R(KPTphys), %eax 903 xorl %ebx, %ebx 904 movl $NKPT, %ecx 905 fillkpt(R(IdlePTD), $PG_RW) 906 907/* install pde's for pt's */ 908 movl R(KPTphys), %eax 909 movl $KPTDI, %ebx 910 movl $NKPT, %ecx 911 fillkpt(R(IdlePTD), $PG_RW) 912 913/* install a pde recursively mapping page directory as a page table */ 914 movl R(IdlePTD), %eax 915 movl $PTDPTDI, %ebx 916 movl $1,%ecx 917 fillkpt(R(IdlePTD), $PG_RW) 918 919 ret 920 921#ifdef BDE_DEBUGGER 922bdb_prepare_paging: 923 cmpl $0,R(_bdb_exists) 924 je bdb_prepare_paging_exit 925 926 subl $6,%esp 927 928 /* 929 * Copy and convert debugger entries from the bootstrap gdt and idt 930 * to the kernel gdt and idt. Everything is still in low memory. 931 * Tracing continues to work after paging is enabled because the 932 * low memory addresses remain valid until everything is relocated. 933 * However, tracing through the setidt() that initializes the trace 934 * trap will crash. 935 */ 936 sgdt (%esp) 937 movl 2(%esp),%esi /* base address of bootstrap gdt */ 938 movl $R(_gdt),%edi 939 movl %edi,2(%esp) /* prepare to load kernel gdt */ 940 movl $8*18/4,%ecx 941 cld 942 rep /* copy gdt */ 943 movsl 944 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 945 movb $0x92,-8+5(%edi) 946 lgdt (%esp) 947 948 sidt (%esp) 949 movl 2(%esp),%esi /* base address of current idt */ 950 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 951 movw 8(%esi),%ax 952 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 953 movl 8+2(%esi),%eax 954 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 955 movl 24+4(%esi),%eax /* same for bpt descriptor */ 956 movw 24(%esi),%ax 957 movl %eax,R(bdb_bpt_ljmp+1) 958 movl 24+2(%esi),%eax 959 movw %ax,R(bdb_bpt_ljmp+5) 960 movl R(_idt),%edi 961 movl %edi,2(%esp) /* prepare to load kernel idt */ 962 movl $8*4/4,%ecx 963 cld 964 rep /* copy idt */ 965 movsl 966 lidt (%esp) 967 968 addl $6,%esp 969 970bdb_prepare_paging_exit: 971 ret 972 973/* Relocate debugger gdt entries and gdt and idt pointers. */ 974bdb_commit_paging: 975 cmpl $0,_bdb_exists 976 je bdb_commit_paging_exit 977 978 movl $gdt+8*9,%eax /* adjust slots 9-17 */ 979 movl $9,%ecx 980reloc_gdt: 981 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 982 addl $8,%eax /* now KERNBASE>>24 */ 983 loop reloc_gdt 984 985 subl $6,%esp 986 sgdt (%esp) 987 addl $KERNBASE,2(%esp) 988 lgdt (%esp) 989 sidt (%esp) 990 addl $KERNBASE,2(%esp) 991 lidt (%esp) 992 addl $6,%esp 993 994 int $3 995 996bdb_commit_paging_exit: 997 ret 998 999#endif /* BDE_DEBUGGER */ 1000