locore.s revision 187948
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 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * from: @(#)locore.s 7.3 (Berkeley) 5/13/91 33 * $FreeBSD: head/sys/i386/i386/locore.s 187948 2009-01-31 11:37:21Z obrien $ 34 * 35 * originally from: locore.s, by William F. Jolitz 36 * 37 * Substantially rewritten by David Greenman, Rod Grimes, 38 * Bruce Evans, Wolfgang Solfrank, Poul-Henning Kamp 39 * and many others. 40 */ 41 42#include "opt_bootp.h" 43#include "opt_compat.h" 44#include "opt_nfsroot.h" 45#include "opt_pmap.h" 46 47#include <sys/syscall.h> 48#include <sys/reboot.h> 49 50#include <machine/asmacros.h> 51#include <machine/cputypes.h> 52#include <machine/psl.h> 53#include <machine/pmap.h> 54#include <machine/specialreg.h> 55 56#include "assym.s" 57 58/* 59 * XXX 60 * 61 * Note: This version greatly munged to avoid various assembler errors 62 * that may be fixed in newer versions of gas. Perhaps newer versions 63 * will have more pleasant appearance. 64 */ 65 66/* 67 * PTmap is recursive pagemap at top of virtual address space. 68 * Within PTmap, the page directory can be found (third indirection). 69 */ 70 .globl PTmap,PTD,PTDpde 71 .set PTmap,(PTDPTDI << PDRSHIFT) 72 .set PTD,PTmap + (PTDPTDI * PAGE_SIZE) 73 .set PTDpde,PTD + (PTDPTDI * PDESIZE) 74 75/* 76 * Compiled KERNBASE location and the kernel load address 77 */ 78 .globl kernbase 79 .set kernbase,KERNBASE 80 .globl kernload 81 .set kernload,KERNLOAD 82 83/* 84 * Globals 85 */ 86 .data 87 ALIGN_DATA /* just to be sure */ 88 89 .space 0x2000 /* space for tmpstk - temporary stack */ 90tmpstk: 91 92 .globl bootinfo 93bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 94 95 .globl KERNend 96KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 97physfree: .long 0 /* phys addr of next free page */ 98 99 .globl IdlePTD 100IdlePTD: .long 0 /* phys addr of kernel PTD */ 101 102#ifdef PAE 103 .globl IdlePDPT 104IdlePDPT: .long 0 /* phys addr of kernel PDPT */ 105#endif 106 107#ifdef SMP 108 .globl KPTphys 109#endif 110KPTphys: .long 0 /* phys addr of kernel page tables */ 111 112 .globl proc0kstack 113proc0uarea: .long 0 /* address of proc 0 uarea (unused)*/ 114proc0kstack: .long 0 /* address of proc 0 kstack space */ 115p0upa: .long 0 /* phys addr of proc0 UAREA (unused) */ 116p0kpa: .long 0 /* phys addr of proc0's STACK */ 117 118vm86phystk: .long 0 /* PA of vm86/bios stack */ 119 120 .globl vm86paddr, vm86pa 121vm86paddr: .long 0 /* address of vm86 region */ 122vm86pa: .long 0 /* phys addr of vm86 region */ 123 124#ifdef PC98 125 .globl pc98_system_parameter 126pc98_system_parameter: 127 .space 0x240 128#endif 129 130/********************************************************************** 131 * 132 * Some handy macros 133 * 134 */ 135 136#define R(foo) ((foo)-KERNBASE) 137 138#define ALLOCPAGES(foo) \ 139 movl R(physfree), %esi ; \ 140 movl $((foo)*PAGE_SIZE), %eax ; \ 141 addl %esi, %eax ; \ 142 movl %eax, R(physfree) ; \ 143 movl %esi, %edi ; \ 144 movl $((foo)*PAGE_SIZE),%ecx ; \ 145 xorl %eax,%eax ; \ 146 cld ; \ 147 rep ; \ 148 stosb 149 150/* 151 * fillkpt 152 * eax = page frame address 153 * ebx = index into page table 154 * ecx = how many pages to map 155 * base = base address of page dir/table 156 * prot = protection bits 157 */ 158#define fillkpt(base, prot) \ 159 shll $PTESHIFT,%ebx ; \ 160 addl base,%ebx ; \ 161 orl $PG_V,%eax ; \ 162 orl prot,%eax ; \ 1631: movl %eax,(%ebx) ; \ 164 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 165 addl $PTESIZE,%ebx ; /* next pte */ \ 166 loop 1b 167 168/* 169 * fillkptphys(prot) 170 * eax = physical address 171 * ecx = how many pages to map 172 * prot = protection bits 173 */ 174#define fillkptphys(prot) \ 175 movl %eax, %ebx ; \ 176 shrl $PAGE_SHIFT, %ebx ; \ 177 fillkpt(R(KPTphys), prot) 178 179 .text 180/********************************************************************** 181 * 182 * This is where the bootblocks start us, set the ball rolling... 183 * 184 */ 185NON_GPROF_ENTRY(btext) 186 187#ifdef PC98 188 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 189 movl $0xa1400,%esi 190 movl $R(pc98_system_parameter),%edi 191 movl $0x0240,%ecx 192 cld 193 rep 194 movsb 195#else /* IBM-PC */ 196/* Tell the bios to warmboot next time */ 197 movw $0x1234,0x472 198#endif /* PC98 */ 199 200/* Set up a real frame in case the double return in newboot is executed. */ 201 pushl %ebp 202 movl %esp, %ebp 203 204/* Don't trust what the BIOS gives for eflags. */ 205 pushl $PSL_KERNEL 206 popfl 207 208/* 209 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 210 * to set %cs, %ds, %es and %ss. 211 */ 212 mov %ds, %ax 213 mov %ax, %fs 214 mov %ax, %gs 215 216/* 217 * Clear the bss. Not all boot programs do it, and it is our job anyway. 218 * 219 * XXX we don't check that there is memory for our bss and page tables 220 * before using it. 221 * 222 * Note: we must be careful to not overwrite an active gdt or idt. They 223 * inactive from now until we switch to new ones, since we don't load any 224 * more segment registers or permit interrupts until after the switch. 225 */ 226 movl $R(end),%ecx 227 movl $R(edata),%edi 228 subl %edi,%ecx 229 xorl %eax,%eax 230 cld 231 rep 232 stosb 233 234 call recover_bootinfo 235 236/* Get onto a stack that we can trust. */ 237/* 238 * XXX this step is delayed in case recover_bootinfo needs to return via 239 * the old stack, but it need not be, since recover_bootinfo actually 240 * returns via the old frame. 241 */ 242 movl $R(tmpstk),%esp 243 244#ifdef PC98 245 /* pc98_machine_type & M_EPSON_PC98 */ 246 testb $0x02,R(pc98_system_parameter)+220 247 jz 3f 248 /* epson_machine_id <= 0x0b */ 249 cmpb $0x0b,R(pc98_system_parameter)+224 250 ja 3f 251 252 /* count up memory */ 253 movl $0x100000,%eax /* next, talley remaining memory */ 254 movl $0xFFF-0x100,%ecx 2551: movl 0(%eax),%ebx /* save location to check */ 256 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 257 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 258 jne 2f 259 movl %ebx,0(%eax) /* restore memory */ 260 addl $PAGE_SIZE,%eax 261 loop 1b 2622: subl $0x100000,%eax 263 shrl $17,%eax 264 movb %al,R(pc98_system_parameter)+1 2653: 266 267 movw R(pc98_system_parameter+0x86),%ax 268 movw %ax,R(cpu_id) 269#endif 270 271 call identify_cpu 272 call create_pagetables 273 274/* 275 * If the CPU has support for VME, turn it on. 276 */ 277 testl $CPUID_VME, R(cpu_feature) 278 jz 1f 279 movl %cr4, %eax 280 orl $CR4_VME, %eax 281 movl %eax, %cr4 2821: 283 284/* Now enable paging */ 285#ifdef PAE 286 movl R(IdlePDPT), %eax 287 movl %eax, %cr3 288 movl %cr4, %eax 289 orl $CR4_PAE, %eax 290 movl %eax, %cr4 291#else 292 movl R(IdlePTD), %eax 293 movl %eax,%cr3 /* load ptd addr into mmu */ 294#endif 295 movl %cr0,%eax /* get control word */ 296 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 297 movl %eax,%cr0 /* and let's page NOW! */ 298 299 pushl $begin /* jump to high virtualized address */ 300 ret 301 302/* now running relocated at KERNBASE where the system is linked to run */ 303begin: 304 /* set up bootstrap stack */ 305 movl proc0kstack,%eax /* location of in-kernel stack */ 306 /* bootstrap stack end location */ 307 leal (KSTACK_PAGES*PAGE_SIZE-PCB_SIZE)(%eax),%esp 308 309 xorl %ebp,%ebp /* mark end of frames */ 310 311#ifdef PAE 312 movl IdlePDPT,%esi 313#else 314 movl IdlePTD,%esi 315#endif 316 movl %esi,(KSTACK_PAGES*PAGE_SIZE-PCB_SIZE+PCB_CR3)(%eax) 317 318 pushl physfree /* value of first for init386(first) */ 319 call init386 /* wire 386 chip for unix operation */ 320 321 /* 322 * Clean up the stack in a way that db_numargs() understands, so 323 * that backtraces in ddb don't underrun the stack. Traps for 324 * inaccessible memory are more fatal than usual this early. 325 */ 326 addl $4,%esp 327 328 call mi_startup /* autoconfiguration, mountroot etc */ 329 /* NOTREACHED */ 330 addl $0,%esp /* for db_numargs() again */ 331 332/* 333 * Signal trampoline, copied to top of user stack 334 */ 335NON_GPROF_ENTRY(sigcode) 336 calll *SIGF_HANDLER(%esp) 337 leal SIGF_UC(%esp),%eax /* get ucontext */ 338 pushl %eax 339 testl $PSL_VM,UC_EFLAGS(%eax) 340 jne 1f 341 mov UC_GS(%eax),%gs /* restore %gs */ 3421: 343 movl $SYS_sigreturn,%eax 344 pushl %eax /* junk to fake return addr. */ 345 int $0x80 /* enter kernel with args */ 346 /* on stack */ 3471: 348 jmp 1b 349 350#ifdef COMPAT_FREEBSD4 351 ALIGN_TEXT 352freebsd4_sigcode: 353 calll *SIGF_HANDLER(%esp) 354 leal SIGF_UC4(%esp),%eax /* get ucontext */ 355 pushl %eax 356 testl $PSL_VM,UC4_EFLAGS(%eax) 357 jne 1f 358 mov UC4_GS(%eax),%gs /* restore %gs */ 3591: 360 movl $344,%eax /* 4.x SYS_sigreturn */ 361 pushl %eax /* junk to fake return addr. */ 362 int $0x80 /* enter kernel with args */ 363 /* on stack */ 3641: 365 jmp 1b 366#endif 367 368#ifdef COMPAT_43 369 ALIGN_TEXT 370osigcode: 371 call *SIGF_HANDLER(%esp) /* call signal handler */ 372 lea SIGF_SC(%esp),%eax /* get sigcontext */ 373 pushl %eax 374 testl $PSL_VM,SC_PS(%eax) 375 jne 9f 376 mov SC_GS(%eax),%gs /* restore %gs */ 3779: 378 movl $103,%eax /* 3.x SYS_sigreturn */ 379 pushl %eax /* junk to fake return addr. */ 380 int $0x80 /* enter kernel with args */ 3810: jmp 0b 382#endif /* COMPAT_43 */ 383 384 ALIGN_TEXT 385esigcode: 386 387 .data 388 .globl szsigcode 389szsigcode: 390 .long esigcode-sigcode 391#ifdef COMPAT_FREEBSD4 392 .globl szfreebsd4_sigcode 393szfreebsd4_sigcode: 394 .long esigcode-freebsd4_sigcode 395#endif 396#ifdef COMPAT_43 397 .globl szosigcode 398szosigcode: 399 .long esigcode-osigcode 400#endif 401 .text 402 403/********************************************************************** 404 * 405 * Recover the bootinfo passed to us from the boot program 406 * 407 */ 408recover_bootinfo: 409 /* 410 * This code is called in different ways depending on what loaded 411 * and started the kernel. This is used to detect how we get the 412 * arguments from the other code and what we do with them. 413 * 414 * Old disk boot blocks: 415 * (*btext)(howto, bootdev, cyloffset, esym); 416 * [return address == 0, and can NOT be returned to] 417 * [cyloffset was not supported by the FreeBSD boot code 418 * and always passed in as 0] 419 * [esym is also known as total in the boot code, and 420 * was never properly supported by the FreeBSD boot code] 421 * 422 * Old diskless netboot code: 423 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 424 * [return address != 0, and can NOT be returned to] 425 * If we are being booted by this code it will NOT work, 426 * so we are just going to halt if we find this case. 427 * 428 * New uniform boot code: 429 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 430 * [return address != 0, and can be returned to] 431 * 432 * There may seem to be a lot of wasted arguments in here, but 433 * that is so the newer boot code can still load very old kernels 434 * and old boot code can load new kernels. 435 */ 436 437 /* 438 * The old style disk boot blocks fake a frame on the stack and 439 * did an lret to get here. The frame on the stack has a return 440 * address of 0. 441 */ 442 cmpl $0,4(%ebp) 443 je olddiskboot 444 445 /* 446 * We have some form of return address, so this is either the 447 * old diskless netboot code, or the new uniform code. That can 448 * be detected by looking at the 5th argument, if it is 0 449 * we are being booted by the new uniform boot code. 450 */ 451 cmpl $0,24(%ebp) 452 je newboot 453 454 /* 455 * Seems we have been loaded by the old diskless boot code, we 456 * don't stand a chance of running as the diskless structure 457 * changed considerably between the two, so just halt. 458 */ 459 hlt 460 461 /* 462 * We have been loaded by the new uniform boot code. 463 * Let's check the bootinfo version, and if we do not understand 464 * it we return to the loader with a status of 1 to indicate this error 465 */ 466newboot: 467 movl 28(%ebp),%ebx /* &bootinfo.version */ 468 movl BI_VERSION(%ebx),%eax 469 cmpl $1,%eax /* We only understand version 1 */ 470 je 1f 471 movl $1,%eax /* Return status */ 472 leave 473 /* 474 * XXX this returns to our caller's caller (as is required) since 475 * we didn't set up a frame and our caller did. 476 */ 477 ret 478 4791: 480 /* 481 * If we have a kernelname copy it in 482 */ 483 movl BI_KERNELNAME(%ebx),%esi 484 cmpl $0,%esi 485 je 2f /* No kernelname */ 486 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 487 movl $R(kernelname),%edi 488 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 489 je 1f 490 movb $'/',(%edi) 491 incl %edi 492 decl %ecx 4931: 494 cld 495 rep 496 movsb 497 4982: 499 /* 500 * Determine the size of the boot loader's copy of the bootinfo 501 * struct. This is impossible to do properly because old versions 502 * of the struct don't contain a size field and there are 2 old 503 * versions with the same version number. 504 */ 505 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 506 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 507 je got_bi_size /* no, sizeless version */ 508 movl BI_SIZE(%ebx),%ecx 509got_bi_size: 510 511 /* 512 * Copy the common part of the bootinfo struct 513 */ 514 movl %ebx,%esi 515 movl $R(bootinfo),%edi 516 cmpl $BOOTINFO_SIZE,%ecx 517 jbe got_common_bi_size 518 movl $BOOTINFO_SIZE,%ecx 519got_common_bi_size: 520 cld 521 rep 522 movsb 523 524#ifdef NFS_ROOT 525#ifndef BOOTP_NFSV3 526 /* 527 * If we have a nfs_diskless structure copy it in 528 */ 529 movl BI_NFS_DISKLESS(%ebx),%esi 530 cmpl $0,%esi 531 je olddiskboot 532 movl $R(nfs_diskless),%edi 533 movl $NFSDISKLESS_SIZE,%ecx 534 cld 535 rep 536 movsb 537 movl $R(nfs_diskless_valid),%edi 538 movl $1,(%edi) 539#endif 540#endif 541 542 /* 543 * The old style disk boot. 544 * (*btext)(howto, bootdev, cyloffset, esym); 545 * Note that the newer boot code just falls into here to pick 546 * up howto and bootdev, cyloffset and esym are no longer used 547 */ 548olddiskboot: 549 movl 8(%ebp),%eax 550 movl %eax,R(boothowto) 551 movl 12(%ebp),%eax 552 movl %eax,R(bootdev) 553 554 ret 555 556 557/********************************************************************** 558 * 559 * Identify the CPU and initialize anything special about it 560 * 561 */ 562identify_cpu: 563 564 /* Try to toggle alignment check flag; does not exist on 386. */ 565 pushfl 566 popl %eax 567 movl %eax,%ecx 568 orl $PSL_AC,%eax 569 pushl %eax 570 popfl 571 pushfl 572 popl %eax 573 xorl %ecx,%eax 574 andl $PSL_AC,%eax 575 pushl %ecx 576 popfl 577 578 testl %eax,%eax 579 jnz try486 580 581 /* NexGen CPU does not have aligment check flag. */ 582 pushfl 583 movl $0x5555, %eax 584 xorl %edx, %edx 585 movl $2, %ecx 586 clc 587 divl %ecx 588 jz trynexgen 589 popfl 590 movl $CPU_386,R(cpu) 591 jmp 3f 592 593trynexgen: 594 popfl 595 movl $CPU_NX586,R(cpu) 596 movl $0x4778654e,R(cpu_vendor) # store vendor string 597 movl $0x72446e65,R(cpu_vendor+4) 598 movl $0x6e657669,R(cpu_vendor+8) 599 movl $0,R(cpu_vendor+12) 600 jmp 3f 601 602try486: /* Try to toggle identification flag; does not exist on early 486s. */ 603 pushfl 604 popl %eax 605 movl %eax,%ecx 606 xorl $PSL_ID,%eax 607 pushl %eax 608 popfl 609 pushfl 610 popl %eax 611 xorl %ecx,%eax 612 andl $PSL_ID,%eax 613 pushl %ecx 614 popfl 615 616 testl %eax,%eax 617 jnz trycpuid 618 movl $CPU_486,R(cpu) 619 620 /* 621 * Check Cyrix CPU 622 * Cyrix CPUs do not change the undefined flags following 623 * execution of the divide instruction which divides 5 by 2. 624 * 625 * Note: CPUID is enabled on M2, so it passes another way. 626 */ 627 pushfl 628 movl $0x5555, %eax 629 xorl %edx, %edx 630 movl $2, %ecx 631 clc 632 divl %ecx 633 jnc trycyrix 634 popfl 635 jmp 3f /* You may use Intel CPU. */ 636 637trycyrix: 638 popfl 639 /* 640 * IBM Bluelighting CPU also doesn't change the undefined flags. 641 * Because IBM doesn't disclose the information for Bluelighting 642 * CPU, we couldn't distinguish it from Cyrix's (including IBM 643 * brand of Cyrix CPUs). 644 */ 645 movl $0x69727943,R(cpu_vendor) # store vendor string 646 movl $0x736e4978,R(cpu_vendor+4) 647 movl $0x64616574,R(cpu_vendor+8) 648 jmp 3f 649 650trycpuid: /* Use the `cpuid' instruction. */ 651 xorl %eax,%eax 652 cpuid # cpuid 0 653 movl %eax,R(cpu_high) # highest capability 654 movl %ebx,R(cpu_vendor) # store vendor string 655 movl %edx,R(cpu_vendor+4) 656 movl %ecx,R(cpu_vendor+8) 657 movb $0,R(cpu_vendor+12) 658 659 movl $1,%eax 660 cpuid # cpuid 1 661 movl %eax,R(cpu_id) # store cpu_id 662 movl %ebx,R(cpu_procinfo) # store cpu_procinfo 663 movl %edx,R(cpu_feature) # store cpu_feature 664 movl %ecx,R(cpu_feature2) # store cpu_feature2 665 rorl $8,%eax # extract family type 666 andl $15,%eax 667 cmpl $5,%eax 668 jae 1f 669 670 /* less than Pentium; must be 486 */ 671 movl $CPU_486,R(cpu) 672 jmp 3f 6731: 674 /* a Pentium? */ 675 cmpl $5,%eax 676 jne 2f 677 movl $CPU_586,R(cpu) 678 jmp 3f 6792: 680 /* Greater than Pentium...call it a Pentium Pro */ 681 movl $CPU_686,R(cpu) 6823: 683 ret 684 685 686/********************************************************************** 687 * 688 * Create the first page directory and its page tables. 689 * 690 */ 691 692create_pagetables: 693 694/* Find end of kernel image (rounded up to a page boundary). */ 695 movl $R(_end),%esi 696 697/* Include symbols, if any. */ 698 movl R(bootinfo+BI_ESYMTAB),%edi 699 testl %edi,%edi 700 je over_symalloc 701 movl %edi,%esi 702 movl $KERNBASE,%edi 703 addl %edi,R(bootinfo+BI_SYMTAB) 704 addl %edi,R(bootinfo+BI_ESYMTAB) 705over_symalloc: 706 707/* If we are told where the end of the kernel space is, believe it. */ 708 movl R(bootinfo+BI_KERNEND),%edi 709 testl %edi,%edi 710 je no_kernend 711 movl %edi,%esi 712no_kernend: 713 714 addl $PDRMASK,%esi /* Play conservative for now, and */ 715 andl $~PDRMASK,%esi /* ... wrap to next 4M. */ 716 movl %esi,R(KERNend) /* save end of kernel */ 717 movl %esi,R(physfree) /* next free page is at end of kernel */ 718 719/* Allocate Kernel Page Tables */ 720 ALLOCPAGES(NKPT) 721 movl %esi,R(KPTphys) 722 723/* Allocate Page Table Directory */ 724#ifdef PAE 725 /* XXX only need 32 bytes (easier for now) */ 726 ALLOCPAGES(1) 727 movl %esi,R(IdlePDPT) 728#endif 729 ALLOCPAGES(NPGPTD) 730 movl %esi,R(IdlePTD) 731 732/* Allocate KSTACK */ 733 ALLOCPAGES(KSTACK_PAGES) 734 movl %esi,R(p0kpa) 735 addl $KERNBASE, %esi 736 movl %esi, R(proc0kstack) 737 738 ALLOCPAGES(1) /* vm86/bios stack */ 739 movl %esi,R(vm86phystk) 740 741 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 742 movl %esi,R(vm86pa) 743 addl $KERNBASE, %esi 744 movl %esi, R(vm86paddr) 745 746/* 747 * Enable PSE and PGE. 748 */ 749#ifndef DISABLE_PSE 750 testl $CPUID_PSE, R(cpu_feature) 751 jz 1f 752 movl $PG_PS, R(pseflag) 753 movl %cr4, %eax 754 orl $CR4_PSE, %eax 755 movl %eax, %cr4 7561: 757#endif 758#ifndef DISABLE_PG_G 759 testl $CPUID_PGE, R(cpu_feature) 760 jz 2f 761 movl $PG_G, R(pgeflag) 762 movl %cr4, %eax 763 orl $CR4_PGE, %eax 764 movl %eax, %cr4 7652: 766#endif 767 768/* 769 * Initialize page table pages mapping physical address zero through the 770 * end of the kernel. All of the page table entries allow read and write 771 * access. Write access to the first physical page is required by bios32 772 * calls, and write access to the first 1 MB of physical memory is required 773 * by ACPI for implementing suspend and resume. We do this even 774 * if we've enabled PSE above, we'll just switch the corresponding kernel 775 * PDEs before we turn on paging. 776 * 777 * XXX: We waste some pages here in the PSE case! DON'T BLINDLY REMOVE 778 * THIS! SMP needs the page table to be there to map the kernel P==V. 779 */ 780 xorl %eax, %eax 781 movl R(KERNend),%ecx 782 shrl $PAGE_SHIFT,%ecx 783 fillkptphys($PG_RW) 784 785/* Map page directory. */ 786#ifdef PAE 787 movl R(IdlePDPT), %eax 788 movl $1, %ecx 789 fillkptphys($PG_RW) 790#endif 791 792 movl R(IdlePTD), %eax 793 movl $NPGPTD, %ecx 794 fillkptphys($PG_RW) 795 796/* Map proc0's KSTACK in the physical way ... */ 797 movl R(p0kpa), %eax 798 movl $(KSTACK_PAGES), %ecx 799 fillkptphys($PG_RW) 800 801/* Map ISA hole */ 802 movl $ISA_HOLE_START, %eax 803 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 804 fillkptphys($PG_RW) 805 806/* Map space for the vm86 region */ 807 movl R(vm86phystk), %eax 808 movl $4, %ecx 809 fillkptphys($PG_RW) 810 811/* Map page 0 into the vm86 page table */ 812 movl $0, %eax 813 movl $0, %ebx 814 movl $1, %ecx 815 fillkpt(R(vm86pa), $PG_RW|PG_U) 816 817/* ...likewise for the ISA hole */ 818 movl $ISA_HOLE_START, %eax 819 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 820 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 821 fillkpt(R(vm86pa), $PG_RW|PG_U) 822 823/* 824 * Create an identity mapping for low physical memory, including the kernel. 825 * The part of this mapping that covers the first 1 MB of physical memory 826 * becomes a permanent part of the kernel's address space. The rest of this 827 * mapping is destroyed in pmap_bootstrap(). Ordinarily, the same page table 828 * pages are shared by the identity mapping and the kernel's native mapping. 829 * However, the permanent identity mapping cannot contain PG_G mappings. 830 * Thus, if the kernel is loaded within the permanent identity mapping, that 831 * page table page must be duplicated and not shared. 832 * 833 * N.B. Due to errata concerning large pages and physical address zero, 834 * a PG_PS mapping is not used. 835 */ 836 movl R(KPTphys), %eax 837 xorl %ebx, %ebx 838 movl $NKPT, %ecx 839 fillkpt(R(IdlePTD), $PG_RW) 840#if KERNLOAD < (1 << PDRSHIFT) 841 testl $PG_G, R(pgeflag) 842 jz 1f 843 ALLOCPAGES(1) 844 movl %esi, %edi 845 movl R(IdlePTD), %eax 846 movl (%eax), %esi 847 movl %edi, (%eax) 848 movl $PAGE_SIZE, %ecx 849 cld 850 rep 851 movsb 8521: 853#endif 854 855/* 856 * For the non-PSE case, install PDEs for PTs covering the KVA. 857 * For the PSE case, do the same, but clobber the ones corresponding 858 * to the kernel (from btext to KERNend) with 4M (2M for PAE) ('PS') 859 * PDEs immediately after. 860 */ 861 movl R(KPTphys), %eax 862 movl $KPTDI, %ebx 863 movl $NKPT, %ecx 864 fillkpt(R(IdlePTD), $PG_RW) 865 cmpl $0,R(pseflag) 866 je done_pde 867 868 movl R(KERNend), %ecx 869 movl $KERNLOAD, %eax 870 subl %eax, %ecx 871 shrl $PDRSHIFT, %ecx 872 movl $(KPTDI+(KERNLOAD/(1 << PDRSHIFT))), %ebx 873 shll $PDESHIFT, %ebx 874 addl R(IdlePTD), %ebx 875 orl $(PG_V|PG_RW|PG_PS), %eax 8761: movl %eax, (%ebx) 877 addl $(1 << PDRSHIFT), %eax 878 addl $PDESIZE, %ebx 879 loop 1b 880 881done_pde: 882/* install a pde recursively mapping page directory as a page table */ 883 movl R(IdlePTD), %eax 884 movl $PTDPTDI, %ebx 885 movl $NPGPTD,%ecx 886 fillkpt(R(IdlePTD), $PG_RW) 887 888#ifdef PAE 889 movl R(IdlePTD), %eax 890 xorl %ebx, %ebx 891 movl $NPGPTD, %ecx 892 fillkpt(R(IdlePDPT), $0x0) 893#endif 894 895 ret 896