locore.s revision 99862
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 99862 2002-07-12 07:56:11Z peter $ 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_compat.h" 48#include "opt_nfsroot.h" 49 50#include <sys/syscall.h> 51#include <sys/reboot.h> 52 53#include <machine/asmacros.h> 54#include <machine/cputypes.h> 55#include <machine/psl.h> 56#include <machine/pmap.h> 57#include <machine/specialreg.h> 58 59#include "assym.s" 60 61#ifdef __AOUT__ 62#define etext _etext 63#define edata _edata 64#define end _end 65#endif 66 67/* 68 * XXX 69 * 70 * Note: This version greatly munged to avoid various assembler errors 71 * that may be fixed in newer versions of gas. Perhaps newer versions 72 * will have more pleasant appearance. 73 */ 74 75/* 76 * PTmap is recursive pagemap at top of virtual address space. 77 * Within PTmap, the page directory can be found (third indirection). 78 * 79 * NOTE: PTDpde, PTmap, and PTD are being defined as address symbols. 80 * In C you access them directly, and not with a '*'. Storage is not being 81 * allocated. They will magically address the correct locations in KVM 82 * which C will treat as normal variables of the type they are defined in 83 * machine/pmap.h, i.e. PTDpde = XX ; to set a PDE entry, NOT *PTDpde = XX; 84 */ 85 .globl PTmap,PTD,PTDpde 86 .set PTmap,(PTDPTDI << PDRSHIFT) 87 .set PTD,PTmap + (PTDPTDI * PAGE_SIZE) 88 .set PTDpde,PTD + (PTDPTDI * PDESIZE) 89 90/* 91 * APTmap, APTD is the alternate recursive pagemap. 92 * It's used when modifying another process's page tables. 93 * See the note above. It is true here as well. 94 */ 95 .globl APTmap,APTD,APTDpde 96 .set APTmap,APTDPTDI << PDRSHIFT 97 .set APTD,APTmap + (APTDPTDI * PAGE_SIZE) 98 .set APTDpde,PTD + (APTDPTDI * PDESIZE) 99 100#ifdef SMP 101/* 102 * Define layout of per-cpu address space. 103 * This is "constructed" in locore.s on the BSP and in mp_machdep.c 104 * for each AP. DO NOT REORDER THESE WITHOUT UPDATING THE REST! 105 */ 106 .globl SMP_prvspace, lapic 107 .set SMP_prvspace,(MPPTDI << PDRSHIFT) 108 .set lapic,SMP_prvspace + (NPTEPG-1) * PAGE_SIZE 109#endif /* SMP */ 110 111/* 112 * Compiled KERNBASE location 113 */ 114 .globl kernbase 115 .set kernbase,KERNBASE 116 117/* 118 * Globals 119 */ 120 .data 121 ALIGN_DATA /* just to be sure */ 122 123 .globl HIDENAME(tmpstk) 124 .space 0x2000 /* space for tmpstk - temporary stack */ 125HIDENAME(tmpstk): 126 127 .globl bootinfo 128bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 129 130 .globl KERNend 131KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 132physfree: .long 0 /* phys addr of next free page */ 133 134#ifdef SMP 135 .globl cpu0prvpage 136cpu0pp: .long 0 /* phys addr cpu0 private pg */ 137cpu0prvpage: .long 0 /* relocated version */ 138 139 .globl SMPpt 140SMPptpa: .long 0 /* phys addr SMP page table */ 141SMPpt: .long 0 /* relocated version */ 142#endif /* SMP */ 143 144 .globl IdlePTD 145IdlePTD: .long 0 /* phys addr of kernel PTD */ 146 147#ifdef SMP 148 .globl KPTphys 149#endif 150KPTphys: .long 0 /* phys addr of kernel page tables */ 151 152 .globl proc0uarea, proc0kstack 153proc0uarea: .long 0 /* address of proc 0 uarea space */ 154proc0kstack: .long 0 /* address of proc 0 kstack space */ 155p0upa: .long 0 /* phys addr of proc0's UAREA */ 156p0kpa: .long 0 /* phys addr of proc0's STACK */ 157 158vm86phystk: .long 0 /* PA of vm86/bios stack */ 159 160 .globl vm86paddr, vm86pa 161vm86paddr: .long 0 /* address of vm86 region */ 162vm86pa: .long 0 /* phys addr of vm86 region */ 163 164#ifdef BDE_DEBUGGER 165 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 166_bdb_exists: .long 0 167#endif 168 169#ifdef PC98 170 .globl pc98_system_parameter 171pc98_system_parameter: 172 .space 0x240 173#endif 174 175/********************************************************************** 176 * 177 * Some handy macros 178 * 179 */ 180 181#define R(foo) ((foo)-KERNBASE) 182 183#define ALLOCPAGES(foo) \ 184 movl R(physfree), %esi ; \ 185 movl $((foo)*PAGE_SIZE), %eax ; \ 186 addl %esi, %eax ; \ 187 movl %eax, R(physfree) ; \ 188 movl %esi, %edi ; \ 189 movl $((foo)*PAGE_SIZE),%ecx ; \ 190 xorl %eax,%eax ; \ 191 cld ; \ 192 rep ; \ 193 stosb 194 195/* 196 * fillkpt 197 * eax = page frame address 198 * ebx = index into page table 199 * ecx = how many pages to map 200 * base = base address of page dir/table 201 * prot = protection bits 202 */ 203#define fillkpt(base, prot) \ 204 shll $2,%ebx ; \ 205 addl base,%ebx ; \ 206 orl $PG_V,%eax ; \ 207 orl prot,%eax ; \ 2081: movl %eax,(%ebx) ; \ 209 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 210 addl $4,%ebx ; /* next pte */ \ 211 loop 1b 212 213/* 214 * fillkptphys(prot) 215 * eax = physical address 216 * ecx = how many pages to map 217 * prot = protection bits 218 */ 219#define fillkptphys(prot) \ 220 movl %eax, %ebx ; \ 221 shrl $PAGE_SHIFT, %ebx ; \ 222 fillkpt(R(KPTphys), prot) 223 224 .text 225/********************************************************************** 226 * 227 * This is where the bootblocks start us, set the ball rolling... 228 * 229 */ 230NON_GPROF_ENTRY(btext) 231 232#ifdef PC98 233 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 234 movl $0xa1400,%esi 235 movl $R(pc98_system_parameter),%edi 236 movl $0x0240,%ecx 237 cld 238 rep 239 movsb 240#else /* IBM-PC */ 241#ifdef BDE_DEBUGGER 242#ifdef BIOS_STEALS_3K 243 cmpl $0x0375c339,0x95504 244#else 245 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 246#endif 247 jne 1f 248 movb $1,R(_bdb_exists) 2491: 250#endif 251/* Tell the bios to warmboot next time */ 252 movw $0x1234,0x472 253#endif /* PC98 */ 254 255/* Set up a real frame in case the double return in newboot is executed. */ 256 pushl %ebp 257 movl %esp, %ebp 258 259/* Don't trust what the BIOS gives for eflags. */ 260 pushl $PSL_KERNEL 261 popfl 262 263/* 264 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 265 * to set %cs, %ds, %es and %ss. 266 */ 267 mov %ds, %ax 268 mov %ax, %fs 269 mov %ax, %gs 270 271 call recover_bootinfo 272 273/* Get onto a stack that we can trust. */ 274/* 275 * XXX this step is delayed in case recover_bootinfo needs to return via 276 * the old stack, but it need not be, since recover_bootinfo actually 277 * returns via the old frame. 278 */ 279 movl $R(HIDENAME(tmpstk)),%esp 280 281#ifdef PC98 282 /* pc98_machine_type & M_EPSON_PC98 */ 283 testb $0x02,R(pc98_system_parameter)+220 284 jz 3f 285 /* epson_machine_id <= 0x0b */ 286 cmpb $0x0b,R(pc98_system_parameter)+224 287 ja 3f 288 289 /* count up memory */ 290 movl $0x100000,%eax /* next, talley remaining memory */ 291 movl $0xFFF-0x100,%ecx 2921: movl 0(%eax),%ebx /* save location to check */ 293 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 294 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 295 jne 2f 296 movl %ebx,0(%eax) /* restore memory */ 297 addl $PAGE_SIZE,%eax 298 loop 1b 2992: subl $0x100000,%eax 300 shrl $17,%eax 301 movb %al,R(pc98_system_parameter)+1 3023: 303 304 movw R(pc98_system_parameter+0x86),%ax 305 movw %ax,R(cpu_id) 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 call create_pagetables 335 336/* 337 * If the CPU has support for VME, turn it on. 338 */ 339 testl $CPUID_VME, R(cpu_feature) 340 jz 1f 341 movl %cr4, %eax 342 orl $CR4_VME, %eax 343 movl %eax, %cr4 3441: 345 346#ifdef BDE_DEBUGGER 347/* 348 * Adjust as much as possible for paging before enabling paging so that the 349 * adjustments can be traced. 350 */ 351 call bdb_prepare_paging 352#endif 353 354/* Now enable paging */ 355 movl R(IdlePTD), %eax 356 movl %eax,%cr3 /* load ptd addr into mmu */ 357 movl %cr0,%eax /* get control word */ 358 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 359 movl %eax,%cr0 /* and let's page NOW! */ 360 361#ifdef BDE_DEBUGGER 362/* 363 * Complete the adjustments for paging so that we can keep tracing through 364 * initi386() after the low (physical) addresses for the gdt and idt become 365 * invalid. 366 */ 367 call bdb_commit_paging 368#endif 369 370 pushl $begin /* jump to high virtualized address */ 371 ret 372 373/* now running relocated at KERNBASE where the system is linked to run */ 374begin: 375 /* set up bootstrap stack */ 376 movl proc0kstack,%eax /* location of in-kernel stack */ 377 /* bootstrap stack end location */ 378 leal (KSTACK_PAGES*PAGE_SIZE-PCB_SIZE)(%eax),%esp 379 380 xorl %ebp,%ebp /* mark end of frames */ 381 382 movl IdlePTD,%esi 383 movl %esi,(KSTACK_PAGES*PAGE_SIZE-PCB_SIZE+PCB_CR3)(%eax) 384 385 pushl physfree /* value of first for init386(first) */ 386 call init386 /* wire 386 chip for unix operation */ 387 388 /* 389 * Clean up the stack in a way that db_numargs() understands, so 390 * that backtraces in ddb don't underrun the stack. Traps for 391 * inaccessible memory are more fatal than usual this early. 392 */ 393 addl $4,%esp 394 395 call mi_startup /* autoconfiguration, mountroot etc */ 396 /* NOTREACHED */ 397 addl $0,%esp /* for db_numargs() again */ 398 399/* 400 * Signal trampoline, copied to top of user stack 401 */ 402NON_GPROF_ENTRY(sigcode) 403 call *SIGF_HANDLER(%esp) /* call signal handler */ 404 lea SIGF_UC(%esp),%eax /* get ucontext_t */ 405 pushl %eax 406 testl $PSL_VM,UC_EFLAGS(%eax) 407 jne 9f 408 movl UC_GS(%eax),%gs /* restore %gs */ 4099: 410 movl $SYS_sigreturn,%eax 411 pushl %eax /* junk to fake return addr. */ 412 int $0x80 /* enter kernel with args */ 4130: jmp 0b 414 415#ifdef COMPAT_43 416 ALIGN_TEXT 417osigcode: 418 call *SIGF_HANDLER(%esp) /* call signal handler */ 419 lea SIGF_SC(%esp),%eax /* get sigcontext */ 420 pushl %eax 421 testl $PSL_VM,SC_PS(%eax) 422 jne 9f 423 movl SC_GS(%eax),%gs /* restore %gs */ 4249: 425 movl $SYS_osigreturn,%eax 426 pushl %eax /* junk to fake return addr. */ 427 int $0x80 /* enter kernel with args */ 4280: jmp 0b 429#endif /* COMPAT_43 */ 430 431 ALIGN_TEXT 432esigcode: 433 434 .data 435 .globl szsigcode, szosigcode 436szsigcode: 437 .long esigcode-sigcode 438#ifdef COMPAT_43 439szosigcode: 440 .long esigcode-osigcode 441#endif 442 .text 443 444/********************************************************************** 445 * 446 * Recover the bootinfo passed to us from the boot program 447 * 448 */ 449recover_bootinfo: 450 /* 451 * This code is called in different ways depending on what loaded 452 * and started the kernel. This is used to detect how we get the 453 * arguments from the other code and what we do with them. 454 * 455 * Old disk boot blocks: 456 * (*btext)(howto, bootdev, cyloffset, esym); 457 * [return address == 0, and can NOT be returned to] 458 * [cyloffset was not supported by the FreeBSD boot code 459 * and always passed in as 0] 460 * [esym is also known as total in the boot code, and 461 * was never properly supported by the FreeBSD boot code] 462 * 463 * Old diskless netboot code: 464 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 465 * [return address != 0, and can NOT be returned to] 466 * If we are being booted by this code it will NOT work, 467 * so we are just going to halt if we find this case. 468 * 469 * New uniform boot code: 470 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 471 * [return address != 0, and can be returned to] 472 * 473 * There may seem to be a lot of wasted arguments in here, but 474 * that is so the newer boot code can still load very old kernels 475 * and old boot code can load new kernels. 476 */ 477 478 /* 479 * The old style disk boot blocks fake a frame on the stack and 480 * did an lret to get here. The frame on the stack has a return 481 * address of 0. 482 */ 483 cmpl $0,4(%ebp) 484 je olddiskboot 485 486 /* 487 * We have some form of return address, so this is either the 488 * old diskless netboot code, or the new uniform code. That can 489 * be detected by looking at the 5th argument, if it is 0 490 * we are being booted by the new uniform boot code. 491 */ 492 cmpl $0,24(%ebp) 493 je newboot 494 495 /* 496 * Seems we have been loaded by the old diskless boot code, we 497 * don't stand a chance of running as the diskless structure 498 * changed considerably between the two, so just halt. 499 */ 500 hlt 501 502 /* 503 * We have been loaded by the new uniform boot code. 504 * Let's check the bootinfo version, and if we do not understand 505 * it we return to the loader with a status of 1 to indicate this error 506 */ 507newboot: 508 movl 28(%ebp),%ebx /* &bootinfo.version */ 509 movl BI_VERSION(%ebx),%eax 510 cmpl $1,%eax /* We only understand version 1 */ 511 je 1f 512 movl $1,%eax /* Return status */ 513 leave 514 /* 515 * XXX this returns to our caller's caller (as is required) since 516 * we didn't set up a frame and our caller did. 517 */ 518 ret 519 5201: 521 /* 522 * If we have a kernelname copy it in 523 */ 524 movl BI_KERNELNAME(%ebx),%esi 525 cmpl $0,%esi 526 je 2f /* No kernelname */ 527 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 528 movl $R(kernelname),%edi 529 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 530 je 1f 531 movb $'/',(%edi) 532 incl %edi 533 decl %ecx 5341: 535 cld 536 rep 537 movsb 538 5392: 540 /* 541 * Determine the size of the boot loader's copy of the bootinfo 542 * struct. This is impossible to do properly because old versions 543 * of the struct don't contain a size field and there are 2 old 544 * versions with the same version number. 545 */ 546 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 547 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 548 je got_bi_size /* no, sizeless version */ 549 movl BI_SIZE(%ebx),%ecx 550got_bi_size: 551 552 /* 553 * Copy the common part of the bootinfo struct 554 */ 555 movl %ebx,%esi 556 movl $R(bootinfo),%edi 557 cmpl $BOOTINFO_SIZE,%ecx 558 jbe got_common_bi_size 559 movl $BOOTINFO_SIZE,%ecx 560got_common_bi_size: 561 cld 562 rep 563 movsb 564 565#ifdef NFS_ROOT 566#ifndef BOOTP_NFSV3 567 /* 568 * If we have a nfs_diskless structure copy it in 569 */ 570 movl BI_NFS_DISKLESS(%ebx),%esi 571 cmpl $0,%esi 572 je olddiskboot 573 movl $R(nfs_diskless),%edi 574 movl $NFSDISKLESS_SIZE,%ecx 575 cld 576 rep 577 movsb 578 movl $R(nfs_diskless_valid),%edi 579 movl $1,(%edi) 580#endif 581#endif 582 583 /* 584 * The old style disk boot. 585 * (*btext)(howto, bootdev, cyloffset, esym); 586 * Note that the newer boot code just falls into here to pick 587 * up howto and bootdev, cyloffset and esym are no longer used 588 */ 589olddiskboot: 590 movl 8(%ebp),%eax 591 movl %eax,R(boothowto) 592 movl 12(%ebp),%eax 593 movl %eax,R(bootdev) 594 595 ret 596 597 598/********************************************************************** 599 * 600 * Identify the CPU and initialize anything special about it 601 * 602 */ 603identify_cpu: 604 605 /* Try to toggle alignment check flag; does not exist on 386. */ 606 pushfl 607 popl %eax 608 movl %eax,%ecx 609 orl $PSL_AC,%eax 610 pushl %eax 611 popfl 612 pushfl 613 popl %eax 614 xorl %ecx,%eax 615 andl $PSL_AC,%eax 616 pushl %ecx 617 popfl 618 619 testl %eax,%eax 620 jnz try486 621 622 /* NexGen CPU does not have aligment check flag. */ 623 pushfl 624 movl $0x5555, %eax 625 xorl %edx, %edx 626 movl $2, %ecx 627 clc 628 divl %ecx 629 jz trynexgen 630 popfl 631 movl $CPU_386,R(cpu) 632 jmp 3f 633 634trynexgen: 635 popfl 636 movl $CPU_NX586,R(cpu) 637 movl $0x4778654e,R(cpu_vendor) # store vendor string 638 movl $0x72446e65,R(cpu_vendor+4) 639 movl $0x6e657669,R(cpu_vendor+8) 640 movl $0,R(cpu_vendor+12) 641 jmp 3f 642 643try486: /* Try to toggle identification flag; does not exist on early 486s. */ 644 pushfl 645 popl %eax 646 movl %eax,%ecx 647 xorl $PSL_ID,%eax 648 pushl %eax 649 popfl 650 pushfl 651 popl %eax 652 xorl %ecx,%eax 653 andl $PSL_ID,%eax 654 pushl %ecx 655 popfl 656 657 testl %eax,%eax 658 jnz trycpuid 659 movl $CPU_486,R(cpu) 660 661 /* 662 * Check Cyrix CPU 663 * Cyrix CPUs do not change the undefined flags following 664 * execution of the divide instruction which divides 5 by 2. 665 * 666 * Note: CPUID is enabled on M2, so it passes another way. 667 */ 668 pushfl 669 movl $0x5555, %eax 670 xorl %edx, %edx 671 movl $2, %ecx 672 clc 673 divl %ecx 674 jnc trycyrix 675 popfl 676 jmp 3f /* You may use Intel CPU. */ 677 678trycyrix: 679 popfl 680 /* 681 * IBM Bluelighting CPU also doesn't change the undefined flags. 682 * Because IBM doesn't disclose the information for Bluelighting 683 * CPU, we couldn't distinguish it from Cyrix's (including IBM 684 * brand of Cyrix CPUs). 685 */ 686 movl $0x69727943,R(cpu_vendor) # store vendor string 687 movl $0x736e4978,R(cpu_vendor+4) 688 movl $0x64616574,R(cpu_vendor+8) 689 jmp 3f 690 691trycpuid: /* Use the `cpuid' instruction. */ 692 xorl %eax,%eax 693 cpuid # cpuid 0 694 movl %eax,R(cpu_high) # highest capability 695 movl %ebx,R(cpu_vendor) # store vendor string 696 movl %edx,R(cpu_vendor+4) 697 movl %ecx,R(cpu_vendor+8) 698 movb $0,R(cpu_vendor+12) 699 700 movl $1,%eax 701 cpuid # cpuid 1 702 movl %eax,R(cpu_id) # store cpu_id 703 movl %edx,R(cpu_feature) # store cpu_feature 704 rorl $8,%eax # extract family type 705 andl $15,%eax 706 cmpl $5,%eax 707 jae 1f 708 709 /* less than Pentium; must be 486 */ 710 movl $CPU_486,R(cpu) 711 jmp 3f 7121: 713 /* a Pentium? */ 714 cmpl $5,%eax 715 jne 2f 716 movl $CPU_586,R(cpu) 717 jmp 3f 7182: 719 /* Greater than Pentium...call it a Pentium Pro */ 720 movl $CPU_686,R(cpu) 7213: 722 ret 723 724 725/********************************************************************** 726 * 727 * Create the first page directory and its page tables. 728 * 729 */ 730 731create_pagetables: 732 733/* Find end of kernel image (rounded up to a page boundary). */ 734 movl $R(_end),%esi 735 736/* Include symbols, if any. */ 737 movl R(bootinfo+BI_ESYMTAB),%edi 738 testl %edi,%edi 739 je over_symalloc 740 movl %edi,%esi 741 movl $KERNBASE,%edi 742 addl %edi,R(bootinfo+BI_SYMTAB) 743 addl %edi,R(bootinfo+BI_ESYMTAB) 744over_symalloc: 745 746/* If we are told where the end of the kernel space is, believe it. */ 747 movl R(bootinfo+BI_KERNEND),%edi 748 testl %edi,%edi 749 je no_kernend 750 movl %edi,%esi 751no_kernend: 752 753 addl $PAGE_MASK,%esi 754 andl $~PAGE_MASK,%esi 755 movl %esi,R(KERNend) /* save end of kernel */ 756 movl %esi,R(physfree) /* next free page is at end of kernel */ 757 758/* Allocate Kernel Page Tables */ 759 ALLOCPAGES(NKPT) 760 movl %esi,R(KPTphys) 761 762/* Allocate Page Table Directory */ 763 ALLOCPAGES(1) 764 movl %esi,R(IdlePTD) 765 766/* Allocate UPAGES */ 767 ALLOCPAGES(UAREA_PAGES) 768 movl %esi,R(p0upa) 769 addl $KERNBASE, %esi 770 movl %esi, R(proc0uarea) 771 772 ALLOCPAGES(KSTACK_PAGES) 773 movl %esi,R(p0kpa) 774 addl $KERNBASE, %esi 775 movl %esi, R(proc0kstack) 776 777 ALLOCPAGES(1) /* vm86/bios stack */ 778 movl %esi,R(vm86phystk) 779 780 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 781 movl %esi,R(vm86pa) 782 addl $KERNBASE, %esi 783 movl %esi, R(vm86paddr) 784 785#ifdef SMP 786/* Allocate cpu0's private data page */ 787 ALLOCPAGES(1) 788 movl %esi,R(cpu0pp) 789 addl $KERNBASE, %esi 790 movl %esi, R(cpu0prvpage) /* relocated to KVM space */ 791 792/* Allocate SMP page table page */ 793 ALLOCPAGES(1) 794 movl %esi,R(SMPptpa) 795 addl $KERNBASE, %esi 796 movl %esi, R(SMPpt) /* relocated to KVM space */ 797#endif /* SMP */ 798 799/* Map read-only from zero to the end of the kernel text section */ 800 xorl %eax, %eax 801#ifdef BDE_DEBUGGER 802/* If the debugger is present, actually map everything read-write. */ 803 cmpl $0,R(_bdb_exists) 804 jne map_read_write 805#endif 806 xorl %edx,%edx 807 movl $R(etext),%ecx 808 addl $PAGE_MASK,%ecx 809 shrl $PAGE_SHIFT,%ecx 810 fillkptphys(%edx) 811 812/* Map read-write, data, bss and symbols */ 813 movl $R(etext),%eax 814 addl $PAGE_MASK, %eax 815 andl $~PAGE_MASK, %eax 816map_read_write: 817 movl $PG_RW,%edx 818 movl R(KERNend),%ecx 819 subl %eax,%ecx 820 shrl $PAGE_SHIFT,%ecx 821 fillkptphys(%edx) 822 823/* Map page directory. */ 824 movl R(IdlePTD), %eax 825 movl $1, %ecx 826 fillkptphys($PG_RW) 827 828/* Map proc0's UPAGES in the physical way ... */ 829 movl R(p0upa), %eax 830 movl $(UAREA_PAGES), %ecx 831 fillkptphys($PG_RW) 832 833/* Map proc0's KSTACK in the physical way ... */ 834 movl R(p0kpa), %eax 835 movl $(KSTACK_PAGES), %ecx 836 fillkptphys($PG_RW) 837 838/* Map ISA hole */ 839 movl $ISA_HOLE_START, %eax 840 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 841 fillkptphys($PG_RW) 842 843/* Map space for the vm86 region */ 844 movl R(vm86phystk), %eax 845 movl $4, %ecx 846 fillkptphys($PG_RW) 847 848/* Map page 0 into the vm86 page table */ 849 movl $0, %eax 850 movl $0, %ebx 851 movl $1, %ecx 852 fillkpt(R(vm86pa), $PG_RW|PG_U) 853 854/* ...likewise for the ISA hole */ 855 movl $ISA_HOLE_START, %eax 856 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 857 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 858 fillkpt(R(vm86pa), $PG_RW|PG_U) 859 860#ifdef SMP 861/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 862 movl R(cpu0pp), %eax 863 movl $1, %ecx 864 fillkptphys($PG_RW) 865 866/* Map SMP page table page into global kmem FWIW */ 867 movl R(SMPptpa), %eax 868 movl $1, %ecx 869 fillkptphys($PG_RW) 870 871/* Map the private page into the SMP page table */ 872 movl R(cpu0pp), %eax 873 movl $0, %ebx /* pte offset = 0 */ 874 movl $1, %ecx /* one private page coming right up */ 875 fillkpt(R(SMPptpa), $PG_RW) 876 877/* ... and put the page table table in the pde. */ 878 movl R(SMPptpa), %eax 879 movl $MPPTDI, %ebx 880 movl $1, %ecx 881 fillkpt(R(IdlePTD), $PG_RW) 882 883/* Fakeup VA for the local apic to allow early traps. */ 884 ALLOCPAGES(1) 885 movl %esi, %eax 886 movl $(NPTEPG-1), %ebx /* pte offset = NTEPG-1 */ 887 movl $1, %ecx /* one private pt coming right up */ 888 fillkpt(R(SMPptpa), $PG_RW) 889#endif /* SMP */ 890 891/* install a pde for temporary double map of bottom of VA */ 892 movl R(KPTphys), %eax 893 xorl %ebx, %ebx 894 movl $NKPT, %ecx 895 fillkpt(R(IdlePTD), $PG_RW) 896 897/* install pde's for pt's */ 898 movl R(KPTphys), %eax 899 movl $KPTDI, %ebx 900 movl $NKPT, %ecx 901 fillkpt(R(IdlePTD), $PG_RW) 902 903/* install a pde recursively mapping page directory as a page table */ 904 movl R(IdlePTD), %eax 905 movl $PTDPTDI, %ebx 906 movl $1,%ecx 907 fillkpt(R(IdlePTD), $PG_RW) 908 909 ret 910 911#ifdef BDE_DEBUGGER 912bdb_prepare_paging: 913 cmpl $0,R(_bdb_exists) 914 je bdb_prepare_paging_exit 915 916 subl $6,%esp 917 918 /* 919 * Copy and convert debugger entries from the bootstrap gdt and idt 920 * to the kernel gdt and idt. Everything is still in low memory. 921 * Tracing continues to work after paging is enabled because the 922 * low memory addresses remain valid until everything is relocated. 923 * However, tracing through the setidt() that initializes the trace 924 * trap will crash. 925 */ 926 sgdt (%esp) 927 movl 2(%esp),%esi /* base address of bootstrap gdt */ 928 movl $R(_gdt),%edi 929 movl %edi,2(%esp) /* prepare to load kernel gdt */ 930 movl $8*18/4,%ecx 931 cld 932 rep /* copy gdt */ 933 movsl 934 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 935 movb $0x92,-8+5(%edi) 936 lgdt (%esp) 937 938 sidt (%esp) 939 movl 2(%esp),%esi /* base address of current idt */ 940 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 941 movw 8(%esi),%ax 942 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 943 movl 8+2(%esi),%eax 944 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 945 movl 24+4(%esi),%eax /* same for bpt descriptor */ 946 movw 24(%esi),%ax 947 movl %eax,R(bdb_bpt_ljmp+1) 948 movl 24+2(%esi),%eax 949 movw %ax,R(bdb_bpt_ljmp+5) 950 movl R(_idt),%edi 951 movl %edi,2(%esp) /* prepare to load kernel idt */ 952 movl $8*4/4,%ecx 953 cld 954 rep /* copy idt */ 955 movsl 956 lidt (%esp) 957 958 addl $6,%esp 959 960bdb_prepare_paging_exit: 961 ret 962 963/* Relocate debugger gdt entries and gdt and idt pointers. */ 964bdb_commit_paging: 965 cmpl $0,_bdb_exists 966 je bdb_commit_paging_exit 967 968 movl $gdt+8*9,%eax /* adjust slots 9-17 */ 969 movl $9,%ecx 970reloc_gdt: 971 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 972 addl $8,%eax /* now KERNBASE>>24 */ 973 loop reloc_gdt 974 975 subl $6,%esp 976 sgdt (%esp) 977 addl $KERNBASE,2(%esp) 978 lgdt (%esp) 979 sidt (%esp) 980 addl $KERNBASE,2(%esp) 981 lidt (%esp) 982 addl $6,%esp 983 984 int $3 985 986bdb_commit_paging_exit: 987 ret 988 989#endif /* BDE_DEBUGGER */ 990