locore.s revision 285686
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 285686 2015-07-19 10:45:58Z kib $ 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#if defined(PAE) || defined(PAE_TABLES) 103 .globl IdlePDPT 104IdlePDPT: .long 0 /* phys addr of kernel PDPT */ 105#endif 106 107 .globl KPTmap 108KPTmap: .long 0 /* address of kernel page tables */ 109 110 .globl KPTphys 111KPTphys: .long 0 /* phys addr of kernel page tables */ 112 113 .globl proc0kstack 114proc0kstack: .long 0 /* address of proc 0 kstack space */ 115p0kpa: .long 0 /* phys addr of proc0's STACK */ 116 117vm86phystk: .long 0 /* PA of vm86/bios stack */ 118 119 .globl vm86paddr, vm86pa 120vm86paddr: .long 0 /* address of vm86 region */ 121vm86pa: .long 0 /* phys addr of vm86 region */ 122 123#ifdef PC98 124 .globl pc98_system_parameter 125pc98_system_parameter: 126 .space 0x240 127#endif 128 129/********************************************************************** 130 * 131 * Some handy macros 132 * 133 */ 134 135#define R(foo) ((foo)-KERNBASE) 136 137#define ALLOCPAGES(foo) \ 138 movl R(physfree), %esi ; \ 139 movl $((foo)*PAGE_SIZE), %eax ; \ 140 addl %esi, %eax ; \ 141 movl %eax, R(physfree) ; \ 142 movl %esi, %edi ; \ 143 movl $((foo)*PAGE_SIZE),%ecx ; \ 144 xorl %eax,%eax ; \ 145 cld ; \ 146 rep ; \ 147 stosb 148 149/* 150 * fillkpt 151 * eax = page frame address 152 * ebx = index into page table 153 * ecx = how many pages to map 154 * base = base address of page dir/table 155 * prot = protection bits 156 */ 157#define fillkpt(base, prot) \ 158 shll $PTESHIFT,%ebx ; \ 159 addl base,%ebx ; \ 160 orl $PG_V,%eax ; \ 161 orl prot,%eax ; \ 1621: movl %eax,(%ebx) ; \ 163 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 164 addl $PTESIZE,%ebx ; /* next pte */ \ 165 loop 1b 166 167/* 168 * fillkptphys(prot) 169 * eax = physical address 170 * ecx = how many pages to map 171 * prot = protection bits 172 */ 173#define fillkptphys(prot) \ 174 movl %eax, %ebx ; \ 175 shrl $PAGE_SHIFT, %ebx ; \ 176 fillkpt(R(KPTphys), prot) 177 178 .text 179/********************************************************************** 180 * 181 * This is where the bootblocks start us, set the ball rolling... 182 * 183 */ 184NON_GPROF_ENTRY(btext) 185 186#ifdef PC98 187 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 188 movl $0xa1400,%esi 189 movl $R(pc98_system_parameter),%edi 190 movl $0x0240,%ecx 191 cld 192 rep 193 movsb 194#else /* IBM-PC */ 195/* Tell the bios to warmboot next time */ 196 movw $0x1234,0x472 197#endif /* PC98 */ 198 199/* Set up a real frame in case the double return in newboot is executed. */ 200 pushl %ebp 201 movl %esp, %ebp 202 203/* Don't trust what the BIOS gives for eflags. */ 204 pushl $PSL_KERNEL 205 popfl 206 207/* 208 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 209 * to set %cs, %ds, %es and %ss. 210 */ 211 mov %ds, %ax 212 mov %ax, %fs 213 mov %ax, %gs 214 215/* 216 * Clear the bss. Not all boot programs do it, and it is our job anyway. 217 * 218 * XXX we don't check that there is memory for our bss and page tables 219 * before using it. 220 * 221 * Note: we must be careful to not overwrite an active gdt or idt. They 222 * inactive from now until we switch to new ones, since we don't load any 223 * more segment registers or permit interrupts until after the switch. 224 */ 225 movl $R(end),%ecx 226 movl $R(edata),%edi 227 subl %edi,%ecx 228 xorl %eax,%eax 229 cld 230 rep 231 stosb 232 233 call recover_bootinfo 234 235/* Get onto a stack that we can trust. */ 236/* 237 * XXX this step is delayed in case recover_bootinfo needs to return via 238 * the old stack, but it need not be, since recover_bootinfo actually 239 * returns via the old frame. 240 */ 241 movl $R(tmpstk),%esp 242 243#ifdef PC98 244 /* pc98_machine_type & M_EPSON_PC98 */ 245 testb $0x02,R(pc98_system_parameter)+220 246 jz 3f 247 /* epson_machine_id <= 0x0b */ 248 cmpb $0x0b,R(pc98_system_parameter)+224 249 ja 3f 250 251 /* count up memory */ 252 movl $0x100000,%eax /* next, talley remaining memory */ 253 movl $0xFFF-0x100,%ecx 2541: movl 0(%eax),%ebx /* save location to check */ 255 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 256 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 257 jne 2f 258 movl %ebx,0(%eax) /* restore memory */ 259 addl $PAGE_SIZE,%eax 260 loop 1b 2612: subl $0x100000,%eax 262 shrl $17,%eax 263 movb %al,R(pc98_system_parameter)+1 2643: 265 266 movw R(pc98_system_parameter+0x86),%ax 267 movw %ax,R(cpu_id) 268#endif 269 270 call identify_cpu 271 call create_pagetables 272 273/* 274 * If the CPU has support for VME, turn it on. 275 */ 276 testl $CPUID_VME, R(cpu_feature) 277 jz 1f 278 movl %cr4, %eax 279 orl $CR4_VME, %eax 280 movl %eax, %cr4 2811: 282 283/* Now enable paging */ 284#if defined(PAE) || defined(PAE_TABLES) 285 movl R(IdlePDPT), %eax 286 movl %eax, %cr3 287 movl %cr4, %eax 288 orl $CR4_PAE, %eax 289 movl %eax, %cr4 290#else 291 movl R(IdlePTD), %eax 292 movl %eax,%cr3 /* load ptd addr into mmu */ 293#endif 294 movl %cr0,%eax /* get control word */ 295 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 296 movl %eax,%cr0 /* and let's page NOW! */ 297 298 pushl $begin /* jump to high virtualized address */ 299 ret 300 301/* now running relocated at KERNBASE where the system is linked to run */ 302begin: 303 /* set up bootstrap stack */ 304 movl proc0kstack,%eax /* location of in-kernel stack */ 305 306 /* 307 * Only use bottom page for init386(). init386() calculates the 308 * PCB + FPU save area size and returns the true top of stack. 309 */ 310 leal PAGE_SIZE(%eax),%esp 311 312 xorl %ebp,%ebp /* mark end of frames */ 313 314 pushl physfree /* value of first for init386(first) */ 315 call init386 /* wire 386 chip for unix operation */ 316 317 /* 318 * Clean up the stack in a way that db_numargs() understands, so 319 * that backtraces in ddb don't underrun the stack. Traps for 320 * inaccessible memory are more fatal than usual this early. 321 */ 322 addl $4,%esp 323 324 /* Switch to true top of stack. */ 325 movl %eax,%esp 326 327 call mi_startup /* autoconfiguration, mountroot etc */ 328 /* NOTREACHED */ 329 addl $0,%esp /* for db_numargs() again */ 330 331/* 332 * Signal trampoline, copied to top of user stack 333 */ 334NON_GPROF_ENTRY(sigcode) 335 calll *SIGF_HANDLER(%esp) 336 leal SIGF_UC(%esp),%eax /* get ucontext */ 337 pushl %eax 338 testl $PSL_VM,UC_EFLAGS(%eax) 339 jne 1f 340 mov UC_GS(%eax),%gs /* restore %gs */ 3411: 342 movl $SYS_sigreturn,%eax 343 pushl %eax /* junk to fake return addr. */ 344 int $0x80 /* enter kernel with args */ 345 /* on stack */ 3461: 347 jmp 1b 348 349#ifdef COMPAT_FREEBSD4 350 ALIGN_TEXT 351freebsd4_sigcode: 352 calll *SIGF_HANDLER(%esp) 353 leal SIGF_UC4(%esp),%eax /* get ucontext */ 354 pushl %eax 355 testl $PSL_VM,UC4_EFLAGS(%eax) 356 jne 1f 357 mov UC4_GS(%eax),%gs /* restore %gs */ 3581: 359 movl $344,%eax /* 4.x SYS_sigreturn */ 360 pushl %eax /* junk to fake return addr. */ 361 int $0x80 /* enter kernel with args */ 362 /* on stack */ 3631: 364 jmp 1b 365#endif 366 367#ifdef COMPAT_43 368 ALIGN_TEXT 369osigcode: 370 call *SIGF_HANDLER(%esp) /* call signal handler */ 371 lea SIGF_SC(%esp),%eax /* get sigcontext */ 372 pushl %eax 373 testl $PSL_VM,SC_PS(%eax) 374 jne 9f 375 mov SC_GS(%eax),%gs /* restore %gs */ 3769: 377 movl $103,%eax /* 3.x SYS_sigreturn */ 378 pushl %eax /* junk to fake return addr. */ 379 int $0x80 /* enter kernel with args */ 3800: jmp 0b 381#endif /* COMPAT_43 */ 382 383 ALIGN_TEXT 384esigcode: 385 386 .data 387 .globl szsigcode 388szsigcode: 389 .long esigcode-sigcode 390#ifdef COMPAT_FREEBSD4 391 .globl szfreebsd4_sigcode 392szfreebsd4_sigcode: 393 .long esigcode-freebsd4_sigcode 394#endif 395#ifdef COMPAT_43 396 .globl szosigcode 397szosigcode: 398 .long esigcode-osigcode 399#endif 400 .text 401 402/********************************************************************** 403 * 404 * Recover the bootinfo passed to us from the boot program 405 * 406 */ 407recover_bootinfo: 408 /* 409 * This code is called in different ways depending on what loaded 410 * and started the kernel. This is used to detect how we get the 411 * arguments from the other code and what we do with them. 412 * 413 * Old disk boot blocks: 414 * (*btext)(howto, bootdev, cyloffset, esym); 415 * [return address == 0, and can NOT be returned to] 416 * [cyloffset was not supported by the FreeBSD boot code 417 * and always passed in as 0] 418 * [esym is also known as total in the boot code, and 419 * was never properly supported by the FreeBSD boot code] 420 * 421 * Old diskless netboot code: 422 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 423 * [return address != 0, and can NOT be returned to] 424 * If we are being booted by this code it will NOT work, 425 * so we are just going to halt if we find this case. 426 * 427 * New uniform boot code: 428 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 429 * [return address != 0, and can be returned to] 430 * 431 * There may seem to be a lot of wasted arguments in here, but 432 * that is so the newer boot code can still load very old kernels 433 * and old boot code can load new kernels. 434 */ 435 436 /* 437 * The old style disk boot blocks fake a frame on the stack and 438 * did an lret to get here. The frame on the stack has a return 439 * address of 0. 440 */ 441 cmpl $0,4(%ebp) 442 je olddiskboot 443 444 /* 445 * We have some form of return address, so this is either the 446 * old diskless netboot code, or the new uniform code. That can 447 * be detected by looking at the 5th argument, if it is 0 448 * we are being booted by the new uniform boot code. 449 */ 450 cmpl $0,24(%ebp) 451 je newboot 452 453 /* 454 * Seems we have been loaded by the old diskless boot code, we 455 * don't stand a chance of running as the diskless structure 456 * changed considerably between the two, so just halt. 457 */ 458 hlt 459 460 /* 461 * We have been loaded by the new uniform boot code. 462 * Let's check the bootinfo version, and if we do not understand 463 * it we return to the loader with a status of 1 to indicate this error 464 */ 465newboot: 466 movl 28(%ebp),%ebx /* &bootinfo.version */ 467 movl BI_VERSION(%ebx),%eax 468 cmpl $1,%eax /* We only understand version 1 */ 469 je 1f 470 movl $1,%eax /* Return status */ 471 leave 472 /* 473 * XXX this returns to our caller's caller (as is required) since 474 * we didn't set up a frame and our caller did. 475 */ 476 ret 477 4781: 479 /* 480 * If we have a kernelname copy it in 481 */ 482 movl BI_KERNELNAME(%ebx),%esi 483 cmpl $0,%esi 484 je 2f /* No kernelname */ 485 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 486 movl $R(kernelname),%edi 487 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 488 je 1f 489 movb $'/',(%edi) 490 incl %edi 491 decl %ecx 4921: 493 cld 494 rep 495 movsb 496 4972: 498 /* 499 * Determine the size of the boot loader's copy of the bootinfo 500 * struct. This is impossible to do properly because old versions 501 * of the struct don't contain a size field and there are 2 old 502 * versions with the same version number. 503 */ 504 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 505 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 506 je got_bi_size /* no, sizeless version */ 507 movl BI_SIZE(%ebx),%ecx 508got_bi_size: 509 510 /* 511 * Copy the common part of the bootinfo struct 512 */ 513 movl %ebx,%esi 514 movl $R(bootinfo),%edi 515 cmpl $BOOTINFO_SIZE,%ecx 516 jbe got_common_bi_size 517 movl $BOOTINFO_SIZE,%ecx 518got_common_bi_size: 519 cld 520 rep 521 movsb 522 523#ifdef NFS_ROOT 524#ifndef BOOTP_NFSV3 525 /* 526 * If we have a nfs_diskless structure copy it in 527 */ 528 movl BI_NFS_DISKLESS(%ebx),%esi 529 cmpl $0,%esi 530 je olddiskboot 531 movl $R(nfs_diskless),%edi 532 movl $NFSDISKLESS_SIZE,%ecx 533 cld 534 rep 535 movsb 536 movl $R(nfs_diskless_valid),%edi 537 movl $1,(%edi) 538#endif 539#endif 540 541 /* 542 * The old style disk boot. 543 * (*btext)(howto, bootdev, cyloffset, esym); 544 * Note that the newer boot code just falls into here to pick 545 * up howto and bootdev, cyloffset and esym are no longer used 546 */ 547olddiskboot: 548 movl 8(%ebp),%eax 549 movl %eax,R(boothowto) 550 movl 12(%ebp),%eax 551 movl %eax,R(bootdev) 552 553 ret 554 555 556/********************************************************************** 557 * 558 * Identify the CPU and initialize anything special about it 559 * 560 */ 561identify_cpu: 562 563 /* Try to toggle alignment check flag; does not exist on 386. */ 564 pushfl 565 popl %eax 566 movl %eax,%ecx 567 orl $PSL_AC,%eax 568 pushl %eax 569 popfl 570 pushfl 571 popl %eax 572 xorl %ecx,%eax 573 andl $PSL_AC,%eax 574 pushl %ecx 575 popfl 576 577 testl %eax,%eax 578 jnz try486 579 580 /* NexGen CPU does not have aligment check flag. */ 581 pushfl 582 movl $0x5555, %eax 583 xorl %edx, %edx 584 movl $2, %ecx 585 clc 586 divl %ecx 587 jz trynexgen 588 popfl 589 movl $CPU_386,R(cpu) 590 jmp 3f 591 592trynexgen: 593 popfl 594 movl $CPU_NX586,R(cpu) 595 movl $0x4778654e,R(cpu_vendor) # store vendor string 596 movl $0x72446e65,R(cpu_vendor+4) 597 movl $0x6e657669,R(cpu_vendor+8) 598 movl $0,R(cpu_vendor+12) 599 jmp 3f 600 601try486: /* Try to toggle identification flag; does not exist on early 486s. */ 602 pushfl 603 popl %eax 604 movl %eax,%ecx 605 xorl $PSL_ID,%eax 606 pushl %eax 607 popfl 608 pushfl 609 popl %eax 610 xorl %ecx,%eax 611 andl $PSL_ID,%eax 612 pushl %ecx 613 popfl 614 615 testl %eax,%eax 616 jnz trycpuid 617 movl $CPU_486,R(cpu) 618 619 /* 620 * Check Cyrix CPU 621 * Cyrix CPUs do not change the undefined flags following 622 * execution of the divide instruction which divides 5 by 2. 623 * 624 * Note: CPUID is enabled on M2, so it passes another way. 625 */ 626 pushfl 627 movl $0x5555, %eax 628 xorl %edx, %edx 629 movl $2, %ecx 630 clc 631 divl %ecx 632 jnc trycyrix 633 popfl 634 jmp 3f /* You may use Intel CPU. */ 635 636trycyrix: 637 popfl 638 /* 639 * IBM Bluelighting CPU also doesn't change the undefined flags. 640 * Because IBM doesn't disclose the information for Bluelighting 641 * CPU, we couldn't distinguish it from Cyrix's (including IBM 642 * brand of Cyrix CPUs). 643 */ 644 movl $0x69727943,R(cpu_vendor) # store vendor string 645 movl $0x736e4978,R(cpu_vendor+4) 646 movl $0x64616574,R(cpu_vendor+8) 647 jmp 3f 648 649trycpuid: /* Use the `cpuid' instruction. */ 650 xorl %eax,%eax 651 cpuid # cpuid 0 652 movl %eax,R(cpu_high) # highest capability 653 movl %ebx,R(cpu_vendor) # store vendor string 654 movl %edx,R(cpu_vendor+4) 655 movl %ecx,R(cpu_vendor+8) 656 movb $0,R(cpu_vendor+12) 657 658 movl $1,%eax 659 cpuid # cpuid 1 660 movl %eax,R(cpu_id) # store cpu_id 661 movl %ebx,R(cpu_procinfo) # store cpu_procinfo 662 movl %edx,R(cpu_feature) # store cpu_feature 663 movl %ecx,R(cpu_feature2) # store cpu_feature2 664 rorl $8,%eax # extract family type 665 andl $15,%eax 666 cmpl $5,%eax 667 jae 1f 668 669 /* less than Pentium; must be 486 */ 670 movl $CPU_486,R(cpu) 671 jmp 3f 6721: 673 /* a Pentium? */ 674 cmpl $5,%eax 675 jne 2f 676 movl $CPU_586,R(cpu) 677 jmp 3f 6782: 679 /* Greater than Pentium...call it a Pentium Pro */ 680 movl $CPU_686,R(cpu) 6813: 682 ret 683 684 685/********************************************************************** 686 * 687 * Create the first page directory and its page tables. 688 * 689 */ 690 691create_pagetables: 692 693/* Find end of kernel image (rounded up to a page boundary). */ 694 movl $R(_end),%esi 695 696/* Include symbols, if any. */ 697 movl R(bootinfo+BI_ESYMTAB),%edi 698 testl %edi,%edi 699 je over_symalloc 700 movl %edi,%esi 701 movl $KERNBASE,%edi 702 addl %edi,R(bootinfo+BI_SYMTAB) 703 addl %edi,R(bootinfo+BI_ESYMTAB) 704over_symalloc: 705 706/* If we are told where the end of the kernel space is, believe it. */ 707 movl R(bootinfo+BI_KERNEND),%edi 708 testl %edi,%edi 709 je no_kernend 710 movl %edi,%esi 711no_kernend: 712 713 addl $PDRMASK,%esi /* Play conservative for now, and */ 714 andl $~PDRMASK,%esi /* ... wrap to next 4M. */ 715 movl %esi,R(KERNend) /* save end of kernel */ 716 movl %esi,R(physfree) /* next free page is at end of kernel */ 717 718/* Allocate Kernel Page Tables */ 719 ALLOCPAGES(NKPT) 720 movl %esi,R(KPTphys) 721 addl $(KERNBASE-(KPTDI<<(PDRSHIFT-PAGE_SHIFT+PTESHIFT))),%esi 722 movl %esi,R(KPTmap) 723 724/* Allocate Page Table Directory */ 725#if defined(PAE) || defined(PAE_TABLES) 726 /* XXX only need 32 bytes (easier for now) */ 727 ALLOCPAGES(1) 728 movl %esi,R(IdlePDPT) 729#endif 730 ALLOCPAGES(NPGPTD) 731 movl %esi,R(IdlePTD) 732 733/* Allocate KSTACK */ 734 ALLOCPAGES(KSTACK_PAGES) 735 movl %esi,R(p0kpa) 736 addl $KERNBASE, %esi 737 movl %esi, R(proc0kstack) 738 739 ALLOCPAGES(1) /* vm86/bios stack */ 740 movl %esi,R(vm86phystk) 741 742 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 743 movl %esi,R(vm86pa) 744 addl $KERNBASE, %esi 745 movl %esi, R(vm86paddr) 746 747/* 748 * Enable PSE and PGE. 749 */ 750#ifndef DISABLE_PSE 751 testl $CPUID_PSE, R(cpu_feature) 752 jz 1f 753 movl $PG_PS, R(pseflag) 754 movl %cr4, %eax 755 orl $CR4_PSE, %eax 756 movl %eax, %cr4 7571: 758#endif 759#ifndef DISABLE_PG_G 760 testl $CPUID_PGE, R(cpu_feature) 761 jz 2f 762 movl $PG_G, R(pgeflag) 763 movl %cr4, %eax 764 orl $CR4_PGE, %eax 765 movl %eax, %cr4 7662: 767#endif 768 769/* 770 * Initialize page table pages mapping physical address zero through the 771 * end of the kernel. All of the page table entries allow read and write 772 * access. Write access to the first physical page is required by bios32 773 * calls, and write access to the first 1 MB of physical memory is required 774 * by ACPI for implementing suspend and resume. We do this even 775 * if we've enabled PSE above, we'll just switch the corresponding kernel 776 * PDEs before we turn on paging. 777 * 778 * XXX: We waste some pages here in the PSE case! 779 */ 780 xorl %eax, %eax 781 movl R(KERNend),%ecx 782 shrl $PAGE_SHIFT,%ecx 783 fillkptphys($PG_RW) 784 785/* Map page table pages. */ 786 movl R(KPTphys),%eax 787 movl $NKPT,%ecx 788 fillkptphys($PG_RW) 789 790/* Map page directory. */ 791#if defined(PAE) || defined(PAE_TABLES) 792 movl R(IdlePDPT), %eax 793 movl $1, %ecx 794 fillkptphys($PG_RW) 795#endif 796 797 movl R(IdlePTD), %eax 798 movl $NPGPTD, %ecx 799 fillkptphys($PG_RW) 800 801/* Map proc0's KSTACK in the physical way ... */ 802 movl R(p0kpa), %eax 803 movl $(KSTACK_PAGES), %ecx 804 fillkptphys($PG_RW) 805 806/* Map ISA hole */ 807 movl $ISA_HOLE_START, %eax 808 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 809 fillkptphys($PG_RW) 810 811/* Map space for the vm86 region */ 812 movl R(vm86phystk), %eax 813 movl $4, %ecx 814 fillkptphys($PG_RW) 815 816/* Map page 0 into the vm86 page table */ 817 movl $0, %eax 818 movl $0, %ebx 819 movl $1, %ecx 820 fillkpt(R(vm86pa), $PG_RW|PG_U) 821 822/* ...likewise for the ISA hole */ 823 movl $ISA_HOLE_START, %eax 824 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 825 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 826 fillkpt(R(vm86pa), $PG_RW|PG_U) 827 828/* 829 * Create an identity mapping for low physical memory, including the kernel. 830 * The part of this mapping that covers the first 1 MB of physical memory 831 * becomes a permanent part of the kernel's address space. The rest of this 832 * mapping is destroyed in pmap_bootstrap(). Ordinarily, the same page table 833 * pages are shared by the identity mapping and the kernel's native mapping. 834 * However, the permanent identity mapping cannot contain PG_G mappings. 835 * Thus, if the kernel is loaded within the permanent identity mapping, that 836 * page table page must be duplicated and not shared. 837 * 838 * N.B. Due to errata concerning large pages and physical address zero, 839 * a PG_PS mapping is not used. 840 */ 841 movl R(KPTphys), %eax 842 xorl %ebx, %ebx 843 movl $NKPT, %ecx 844 fillkpt(R(IdlePTD), $PG_RW) 845#if KERNLOAD < (1 << PDRSHIFT) 846 testl $PG_G, R(pgeflag) 847 jz 1f 848 ALLOCPAGES(1) 849 movl %esi, %edi 850 movl R(IdlePTD), %eax 851 movl (%eax), %esi 852 movl %edi, (%eax) 853 movl $PAGE_SIZE, %ecx 854 cld 855 rep 856 movsb 8571: 858#endif 859 860/* 861 * For the non-PSE case, install PDEs for PTs covering the KVA. 862 * For the PSE case, do the same, but clobber the ones corresponding 863 * to the kernel (from btext to KERNend) with 4M (2M for PAE) ('PS') 864 * PDEs immediately after. 865 */ 866 movl R(KPTphys), %eax 867 movl $KPTDI, %ebx 868 movl $NKPT, %ecx 869 fillkpt(R(IdlePTD), $PG_RW) 870 cmpl $0,R(pseflag) 871 je done_pde 872 873 movl R(KERNend), %ecx 874 movl $KERNLOAD, %eax 875 subl %eax, %ecx 876 shrl $PDRSHIFT, %ecx 877 movl $(KPTDI+(KERNLOAD/(1 << PDRSHIFT))), %ebx 878 shll $PDESHIFT, %ebx 879 addl R(IdlePTD), %ebx 880 orl $(PG_V|PG_RW|PG_PS), %eax 8811: movl %eax, (%ebx) 882 addl $(1 << PDRSHIFT), %eax 883 addl $PDESIZE, %ebx 884 loop 1b 885 886done_pde: 887/* install a pde recursively mapping page directory as a page table */ 888 movl R(IdlePTD), %eax 889 movl $PTDPTDI, %ebx 890 movl $NPGPTD,%ecx 891 fillkpt(R(IdlePTD), $PG_RW) 892 893#if defined(PAE) || defined(PAE_TABLES) 894 movl R(IdlePTD), %eax 895 xorl %ebx, %ebx 896 movl $NPGPTD, %ecx 897 fillkpt(R(IdlePDPT), $0x0) 898#endif 899 900 ret 901 902#ifdef XENHVM 903/* Xen Hypercall page */ 904 .text 905.p2align PAGE_SHIFT, 0x90 /* Hypercall_page needs to be PAGE aligned */ 906 907NON_GPROF_ENTRY(hypercall_page) 908 .skip 0x1000, 0x90 /* Fill with "nop"s */ 909#endif 910