Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/i386/i386/locore.s
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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 * $FreeBSD$ 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/reboot.h> 48 49 #include <machine/asmacros.h> 50 #include <machine/cputypes.h> 51 #include <machine/psl.h> 52 #include <machine/pmap.h> 53 #include <machine/specialreg.h> 54 55 #include "assym.s" 56 57 /* 58 * XXX 59 * 60 * Note: This version greatly munged to avoid various assembler errors 61 * that may be fixed in newer versions of gas. Perhaps newer versions 62 * will have more pleasant appearance. 63 */ 64 65 /* 66 * PTmap is recursive pagemap at top of virtual address space. 67 * Within PTmap, the page directory can be found (third indirection). 68 */ 69 .globl PTmap,PTD,PTDpde 70 .set PTmap,(PTDPTDI << PDRSHIFT) 71 .set PTD,PTmap + (PTDPTDI * PAGE_SIZE) 72 .set PTDpde,PTD + (PTDPTDI * PDESIZE) 73 74 /* 75 * Compiled KERNBASE location and the kernel load address 76 */ 77 .globl kernbase 78 .set kernbase,KERNBASE 79 .globl kernload 80 .set kernload,KERNLOAD 81 82 /* 83 * Globals 84 */ 85 .data 86 ALIGN_DATA /* just to be sure */ 87 88 .space 0x2000 /* space for tmpstk - temporary stack */ 89 tmpstk: 90 91 .globl bootinfo 92 bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 93 94 .globl KERNend 95 KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 96 physfree: .long 0 /* phys addr of next free page */ 97 98 .globl IdlePTD 99 IdlePTD: .long 0 /* phys addr of kernel PTD */ 100 101 #if defined(PAE) || defined(PAE_TABLES) 102 .globl IdlePDPT 103 IdlePDPT: .long 0 /* phys addr of kernel PDPT */ 104 #endif 105 106 .globl KPTmap 107 KPTmap: .long 0 /* address of kernel page tables */ 108 109 .globl KPTphys 110 KPTphys: .long 0 /* phys addr of kernel page tables */ 111 112 .globl proc0kstack 113 proc0kstack: .long 0 /* address of proc 0 kstack space */ 114 p0kpa: .long 0 /* phys addr of proc0's STACK */ 115 116 vm86phystk: .long 0 /* PA of vm86/bios stack */ 117 118 .globl vm86paddr, vm86pa 119 vm86paddr: .long 0 /* address of vm86 region */ 120 vm86pa: .long 0 /* phys addr of vm86 region */ 121 122 #ifdef PC98 123 .globl pc98_system_parameter 124 pc98_system_parameter: 125 .space 0x240 126 #endif 127 128 /********************************************************************** 129 * 130 * Some handy macros 131 * 132 */ 133 134 #define R(foo) ((foo)-KERNBASE) 135 136 #define ALLOCPAGES(foo) \ 137 movl R(physfree), %esi ; \ 138 movl $((foo)*PAGE_SIZE), %eax ; \ 139 addl %esi, %eax ; \ 140 movl %eax, R(physfree) ; \ 141 movl %esi, %edi ; \ 142 movl $((foo)*PAGE_SIZE),%ecx ; \ 143 xorl %eax,%eax ; \ 144 cld ; \ 145 rep ; \ 146 stosb 147 148 /* 149 * fillkpt 150 * eax = page frame address 151 * ebx = index into page table 152 * ecx = how many pages to map 153 * base = base address of page dir/table 154 * prot = protection bits 155 */ 156 #define fillkpt(base, prot) \ 157 shll $PTESHIFT,%ebx ; \ 158 addl base,%ebx ; \ 159 orl $PG_V,%eax ; \ 160 orl prot,%eax ; \ 161 1: movl %eax,(%ebx) ; \ 162 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 163 addl $PTESIZE,%ebx ; /* next pte */ \ 164 loop 1b 165 166 /* 167 * fillkptphys(prot) 168 * eax = physical address 169 * ecx = how many pages to map 170 * prot = protection bits 171 */ 172 #define fillkptphys(prot) \ 173 movl %eax, %ebx ; \ 174 shrl $PAGE_SHIFT, %ebx ; \ 175 fillkpt(R(KPTphys), prot) 176 177 .text 178 /********************************************************************** 179 * 180 * This is where the bootblocks start us, set the ball rolling... 181 * 182 */ 183 NON_GPROF_ENTRY(btext) 184 185 #ifdef PC98 186 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 187 movl $0xa1400,%esi 188 movl $R(pc98_system_parameter),%edi 189 movl $0x0240,%ecx 190 cld 191 rep 192 movsb 193 #else /* IBM-PC */ 194 /* Tell the bios to warmboot next time */ 195 movw $0x1234,0x472 196 #endif /* PC98 */ 197 198 /* Set up a real frame in case the double return in newboot is executed. */ 199 pushl %ebp 200 movl %esp, %ebp 201 202 /* Don't trust what the BIOS gives for eflags. */ 203 pushl $PSL_KERNEL 204 popfl 205 206 /* 207 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 208 * to set %cs, %ds, %es and %ss. 209 */ 210 mov %ds, %ax 211 mov %ax, %fs 212 mov %ax, %gs 213 214 /* 215 * Clear the bss. Not all boot programs do it, and it is our job anyway. 216 * 217 * XXX we don't check that there is memory for our bss and page tables 218 * before using it. 219 * 220 * Note: we must be careful to not overwrite an active gdt or idt. They 221 * inactive from now until we switch to new ones, since we don't load any 222 * more segment registers or permit interrupts until after the switch. 223 */ 224 movl $R(__bss_end),%ecx 225 movl $R(__bss_start),%edi 226 subl %edi,%ecx 227 xorl %eax,%eax 228 cld 229 rep 230 stosb 231 232 call recover_bootinfo 233 234 /* Get onto a stack that we can trust. */ 235 /* 236 * XXX this step is delayed in case recover_bootinfo needs to return via 237 * the old stack, but it need not be, since recover_bootinfo actually 238 * returns via the old frame. 239 */ 240 movl $R(tmpstk),%esp 241 242 #ifdef PC98 243 /* pc98_machine_type & M_EPSON_PC98 */ 244 testb $0x02,R(pc98_system_parameter)+220 245 jz 3f 246 /* epson_machine_id <= 0x0b */ 247 cmpb $0x0b,R(pc98_system_parameter)+224 248 ja 3f 249 250 /* count up memory */ 251 movl $0x100000,%eax /* next, talley remaining memory */ 252 movl $0xFFF-0x100,%ecx 253 1: movl 0(%eax),%ebx /* save location to check */ 254 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 255 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 256 jne 2f 257 movl %ebx,0(%eax) /* restore memory */ 258 addl $PAGE_SIZE,%eax 259 loop 1b 260 2: subl $0x100000,%eax 261 shrl $17,%eax 262 movb %al,R(pc98_system_parameter)+1 263 3: 264 265 movw R(pc98_system_parameter+0x86),%ax 266 movw %ax,R(cpu_id) 267 #endif 268 269 call identify_cpu 270 call create_pagetables 271 272 /* 273 * If the CPU has support for VME, turn it on. 274 */ 275 testl $CPUID_VME, R(cpu_feature) 276 jz 1f 277 movl %cr4, %eax 278 orl $CR4_VME, %eax 279 movl %eax, %cr4 280 1: 281 282 /* Now enable paging */ 283 #if defined(PAE) || defined(PAE_TABLES) 284 movl R(IdlePDPT), %eax 285 movl %eax, %cr3 286 movl %cr4, %eax 287 orl $CR4_PAE, %eax 288 movl %eax, %cr4 289 #else 290 movl R(IdlePTD), %eax 291 movl %eax,%cr3 /* load ptd addr into mmu */ 292 #endif 293 movl %cr0,%eax /* get control word */ 294 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 295 movl %eax,%cr0 /* and let's page NOW! */ 296 297 pushl $begin /* jump to high virtualized address */ 298 ret 299 300 /* now running relocated at KERNBASE where the system is linked to run */ 301 begin: 302 /* set up bootstrap stack */ 303 movl proc0kstack,%eax /* location of in-kernel stack */ 304 305 /* 306 * Only use bottom page for init386(). init386() calculates the 307 * PCB + FPU save area size and returns the true top of stack. 308 */ 309 leal PAGE_SIZE(%eax),%esp 310 311 xorl %ebp,%ebp /* mark end of frames */ 312 313 pushl physfree /* value of first for init386(first) */ 314 call init386 /* wire 386 chip for unix operation */ 315 316 /* 317 * Clean up the stack in a way that db_numargs() understands, so 318 * that backtraces in ddb don't underrun the stack. Traps for 319 * inaccessible memory are more fatal than usual this early. 320 */ 321 addl $4,%esp 322 323 /* Switch to true top of stack. */ 324 movl %eax,%esp 325 326 call mi_startup /* autoconfiguration, mountroot etc */ 327 /* NOTREACHED */ 328 addl $0,%esp /* for db_numargs() again */ 329 330 /********************************************************************** 331 * 332 * Recover the bootinfo passed to us from the boot program 333 * 334 */ 335 recover_bootinfo: 336 /* 337 * This code is called in different ways depending on what loaded 338 * and started the kernel. This is used to detect how we get the 339 * arguments from the other code and what we do with them. 340 * 341 * Old disk boot blocks: 342 * (*btext)(howto, bootdev, cyloffset, esym); 343 * [return address == 0, and can NOT be returned to] 344 * [cyloffset was not supported by the FreeBSD boot code 345 * and always passed in as 0] 346 * [esym is also known as total in the boot code, and 347 * was never properly supported by the FreeBSD boot code] 348 * 349 * Old diskless netboot code: 350 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 351 * [return address != 0, and can NOT be returned to] 352 * If we are being booted by this code it will NOT work, 353 * so we are just going to halt if we find this case. 354 * 355 * New uniform boot code: 356 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 357 * [return address != 0, and can be returned to] 358 * 359 * There may seem to be a lot of wasted arguments in here, but 360 * that is so the newer boot code can still load very old kernels 361 * and old boot code can load new kernels. 362 */ 363 364 /* 365 * The old style disk boot blocks fake a frame on the stack and 366 * did an lret to get here. The frame on the stack has a return 367 * address of 0. 368 */ 369 cmpl $0,4(%ebp) 370 je olddiskboot 371 372 /* 373 * We have some form of return address, so this is either the 374 * old diskless netboot code, or the new uniform code. That can 375 * be detected by looking at the 5th argument, if it is 0 376 * we are being booted by the new uniform boot code. 377 */ 378 cmpl $0,24(%ebp) 379 je newboot 380 381 /* 382 * Seems we have been loaded by the old diskless boot code, we 383 * don't stand a chance of running as the diskless structure 384 * changed considerably between the two, so just halt. 385 */ 386 hlt 387 388 /* 389 * We have been loaded by the new uniform boot code. 390 * Let's check the bootinfo version, and if we do not understand 391 * it we return to the loader with a status of 1 to indicate this error 392 */ 393 newboot: 394 movl 28(%ebp),%ebx /* &bootinfo.version */ 395 movl BI_VERSION(%ebx),%eax 396 cmpl $1,%eax /* We only understand version 1 */ 397 je 1f 398 movl $1,%eax /* Return status */ 399 leave 400 /* 401 * XXX this returns to our caller's caller (as is required) since 402 * we didn't set up a frame and our caller did. 403 */ 404 ret 405 406 1: 407 /* 408 * If we have a kernelname copy it in 409 */ 410 movl BI_KERNELNAME(%ebx),%esi 411 cmpl $0,%esi 412 je 2f /* No kernelname */ 413 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 414 movl $R(kernelname),%edi 415 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 416 je 1f 417 movb $'/',(%edi) 418 incl %edi 419 decl %ecx 420 1: 421 cld 422 rep 423 movsb 424 425 2: 426 /* 427 * Determine the size of the boot loader's copy of the bootinfo 428 * struct. This is impossible to do properly because old versions 429 * of the struct don't contain a size field and there are 2 old 430 * versions with the same version number. 431 */ 432 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 433 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 434 je got_bi_size /* no, sizeless version */ 435 movl BI_SIZE(%ebx),%ecx 436 got_bi_size: 437 438 /* 439 * Copy the common part of the bootinfo struct 440 */ 441 movl %ebx,%esi 442 movl $R(bootinfo),%edi 443 cmpl $BOOTINFO_SIZE,%ecx 444 jbe got_common_bi_size 445 movl $BOOTINFO_SIZE,%ecx 446 got_common_bi_size: 447 cld 448 rep 449 movsb 450 451 #ifdef NFS_ROOT 452 #ifndef BOOTP_NFSV3 453 /* 454 * If we have a nfs_diskless structure copy it in 455 */ 456 movl BI_NFS_DISKLESS(%ebx),%esi 457 cmpl $0,%esi 458 je olddiskboot 459 movl $R(nfs_diskless),%edi 460 movl $NFSDISKLESS_SIZE,%ecx 461 cld 462 rep 463 movsb 464 movl $R(nfs_diskless_valid),%edi 465 movl $1,(%edi) 466 #endif 467 #endif 468 469 /* 470 * The old style disk boot. 471 * (*btext)(howto, bootdev, cyloffset, esym); 472 * Note that the newer boot code just falls into here to pick 473 * up howto and bootdev, cyloffset and esym are no longer used 474 */ 475 olddiskboot: 476 movl 8(%ebp),%eax 477 movl %eax,R(boothowto) 478 movl 12(%ebp),%eax 479 movl %eax,R(bootdev) 480 481 ret 482 483 484 /********************************************************************** 485 * 486 * Identify the CPU and initialize anything special about it 487 * 488 */ 489 ENTRY(identify_cpu) 490 491 pushl %ebx 492 493 /* Try to toggle alignment check flag; does not exist on 386. */ 494 pushfl 495 popl %eax 496 movl %eax,%ecx 497 orl $PSL_AC,%eax 498 pushl %eax 499 popfl 500 pushfl 501 popl %eax 502 xorl %ecx,%eax 503 andl $PSL_AC,%eax 504 pushl %ecx 505 popfl 506 507 testl %eax,%eax 508 jnz try486 509 510 /* NexGen CPU does not have aligment check flag. */ 511 pushfl 512 movl $0x5555, %eax 513 xorl %edx, %edx 514 movl $2, %ecx 515 clc 516 divl %ecx 517 jz trynexgen 518 popfl 519 movl $CPU_386,R(cpu) 520 jmp 3f 521 522 trynexgen: 523 popfl 524 movl $CPU_NX586,R(cpu) 525 movl $0x4778654e,R(cpu_vendor) # store vendor string 526 movl $0x72446e65,R(cpu_vendor+4) 527 movl $0x6e657669,R(cpu_vendor+8) 528 movl $0,R(cpu_vendor+12) 529 jmp 3f 530 531 try486: /* Try to toggle identification flag; does not exist on early 486s. */ 532 pushfl 533 popl %eax 534 movl %eax,%ecx 535 xorl $PSL_ID,%eax 536 pushl %eax 537 popfl 538 pushfl 539 popl %eax 540 xorl %ecx,%eax 541 andl $PSL_ID,%eax 542 pushl %ecx 543 popfl 544 545 testl %eax,%eax 546 jnz trycpuid 547 movl $CPU_486,R(cpu) 548 549 /* 550 * Check Cyrix CPU 551 * Cyrix CPUs do not change the undefined flags following 552 * execution of the divide instruction which divides 5 by 2. 553 * 554 * Note: CPUID is enabled on M2, so it passes another way. 555 */ 556 pushfl 557 movl $0x5555, %eax 558 xorl %edx, %edx 559 movl $2, %ecx 560 clc 561 divl %ecx 562 jnc trycyrix 563 popfl 564 jmp 3f /* You may use Intel CPU. */ 565 566 trycyrix: 567 popfl 568 /* 569 * IBM Bluelighting CPU also doesn't change the undefined flags. 570 * Because IBM doesn't disclose the information for Bluelighting 571 * CPU, we couldn't distinguish it from Cyrix's (including IBM 572 * brand of Cyrix CPUs). 573 */ 574 movl $0x69727943,R(cpu_vendor) # store vendor string 575 movl $0x736e4978,R(cpu_vendor+4) 576 movl $0x64616574,R(cpu_vendor+8) 577 jmp 3f 578 579 trycpuid: /* Use the `cpuid' instruction. */ 580 xorl %eax,%eax 581 cpuid # cpuid 0 582 movl %eax,R(cpu_high) # highest capability 583 movl %ebx,R(cpu_vendor) # store vendor string 584 movl %edx,R(cpu_vendor+4) 585 movl %ecx,R(cpu_vendor+8) 586 movb $0,R(cpu_vendor+12) 587 588 movl $1,%eax 589 cpuid # cpuid 1 590 movl %eax,R(cpu_id) # store cpu_id 591 movl %ebx,R(cpu_procinfo) # store cpu_procinfo 592 movl %edx,R(cpu_feature) # store cpu_feature 593 movl %ecx,R(cpu_feature2) # store cpu_feature2 594 rorl $8,%eax # extract family type 595 andl $15,%eax 596 cmpl $5,%eax 597 jae 1f 598 599 /* less than Pentium; must be 486 */ 600 movl $CPU_486,R(cpu) 601 jmp 3f 602 1: 603 /* a Pentium? */ 604 cmpl $5,%eax 605 jne 2f 606 movl $CPU_586,R(cpu) 607 jmp 3f 608 2: 609 /* Greater than Pentium...call it a Pentium Pro */ 610 movl $CPU_686,R(cpu) 611 3: 612 popl %ebx 613 ret 614 END(identify_cpu) 615 616 617 /********************************************************************** 618 * 619 * Create the first page directory and its page tables. 620 * 621 */ 622 623 create_pagetables: 624 625 /* Find end of kernel image (rounded up to a page boundary). */ 626 movl $R(_end),%esi 627 628 /* Include symbols, if any. */ 629 movl R(bootinfo+BI_ESYMTAB),%edi 630 testl %edi,%edi 631 je over_symalloc 632 movl %edi,%esi 633 movl $KERNBASE,%edi 634 addl %edi,R(bootinfo+BI_SYMTAB) 635 addl %edi,R(bootinfo+BI_ESYMTAB) 636 over_symalloc: 637 638 /* If we are told where the end of the kernel space is, believe it. */ 639 movl R(bootinfo+BI_KERNEND),%edi 640 testl %edi,%edi 641 je no_kernend 642 movl %edi,%esi 643 no_kernend: 644 645 addl $PDRMASK,%esi /* Play conservative for now, and */ 646 andl $~PDRMASK,%esi /* ... wrap to next 4M. */ 647 movl %esi,R(KERNend) /* save end of kernel */ 648 movl %esi,R(physfree) /* next free page is at end of kernel */ 649 650 /* Allocate Kernel Page Tables */ 651 ALLOCPAGES(NKPT) 652 movl %esi,R(KPTphys) 653 addl $(KERNBASE-(KPTDI<<(PDRSHIFT-PAGE_SHIFT+PTESHIFT))),%esi 654 movl %esi,R(KPTmap) 655 656 /* Allocate Page Table Directory */ 657 #if defined(PAE) || defined(PAE_TABLES) 658 /* XXX only need 32 bytes (easier for now) */ 659 ALLOCPAGES(1) 660 movl %esi,R(IdlePDPT) 661 #endif 662 ALLOCPAGES(NPGPTD) 663 movl %esi,R(IdlePTD) 664 665 /* Allocate KSTACK */ 666 ALLOCPAGES(TD0_KSTACK_PAGES) 667 movl %esi,R(p0kpa) 668 addl $KERNBASE, %esi 669 movl %esi, R(proc0kstack) 670 671 ALLOCPAGES(1) /* vm86/bios stack */ 672 movl %esi,R(vm86phystk) 673 674 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 675 movl %esi,R(vm86pa) 676 addl $KERNBASE, %esi 677 movl %esi, R(vm86paddr) 678 679 /* 680 * Enable PSE and PGE. 681 */ 682 #ifndef DISABLE_PSE 683 testl $CPUID_PSE, R(cpu_feature) 684 jz 1f 685 movl $PG_PS, R(pseflag) 686 movl %cr4, %eax 687 orl $CR4_PSE, %eax 688 movl %eax, %cr4 689 1: 690 #endif 691 #ifndef DISABLE_PG_G 692 testl $CPUID_PGE, R(cpu_feature) 693 jz 2f 694 movl $PG_G, R(pgeflag) 695 movl %cr4, %eax 696 orl $CR4_PGE, %eax 697 movl %eax, %cr4 698 2: 699 #endif 700 701 /* 702 * Initialize page table pages mapping physical address zero through the 703 * end of the kernel. All of the page table entries allow read and write 704 * access. Write access to the first physical page is required by bios32 705 * calls, and write access to the first 1 MB of physical memory is required 706 * by ACPI for implementing suspend and resume. We do this even 707 * if we've enabled PSE above, we'll just switch the corresponding kernel 708 * PDEs before we turn on paging. 709 * 710 * XXX: We waste some pages here in the PSE case! 711 */ 712 xorl %eax, %eax 713 movl R(KERNend),%ecx 714 shrl $PAGE_SHIFT,%ecx 715 fillkptphys($PG_RW) 716 717 /* Map page table pages. */ 718 movl R(KPTphys),%eax 719 movl $NKPT,%ecx 720 fillkptphys($PG_RW) 721 722 /* Map page directory. */ 723 #if defined(PAE) || defined(PAE_TABLES) 724 movl R(IdlePDPT), %eax 725 movl $1, %ecx 726 fillkptphys($PG_RW) 727 #endif 728 729 movl R(IdlePTD), %eax 730 movl $NPGPTD, %ecx 731 fillkptphys($PG_RW) 732 733 /* Map proc0's KSTACK in the physical way ... */ 734 movl R(p0kpa), %eax 735 movl $(TD0_KSTACK_PAGES), %ecx 736 fillkptphys($PG_RW) 737 738 /* Map ISA hole */ 739 movl $ISA_HOLE_START, %eax 740 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 741 fillkptphys($PG_RW) 742 743 /* Map space for the vm86 region */ 744 movl R(vm86phystk), %eax 745 movl $4, %ecx 746 fillkptphys($PG_RW) 747 748 /* Map page 0 into the vm86 page table */ 749 movl $0, %eax 750 movl $0, %ebx 751 movl $1, %ecx 752 fillkpt(R(vm86pa), $PG_RW|PG_U) 753 754 /* ...likewise for the ISA hole */ 755 movl $ISA_HOLE_START, %eax 756 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 757 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 758 fillkpt(R(vm86pa), $PG_RW|PG_U) 759 760 /* 761 * Create an identity mapping for low physical memory, including the kernel. 762 * The part of this mapping that covers the first 1 MB of physical memory 763 * becomes a permanent part of the kernel's address space. The rest of this 764 * mapping is destroyed in pmap_bootstrap(). Ordinarily, the same page table 765 * pages are shared by the identity mapping and the kernel's native mapping. 766 * However, the permanent identity mapping cannot contain PG_G mappings. 767 * Thus, if the kernel is loaded within the permanent identity mapping, that 768 * page table page must be duplicated and not shared. 769 * 770 * N.B. Due to errata concerning large pages and physical address zero, 771 * a PG_PS mapping is not used. 772 */ 773 movl R(KPTphys), %eax 774 xorl %ebx, %ebx 775 movl $NKPT, %ecx 776 fillkpt(R(IdlePTD), $PG_RW) 777 #if KERNLOAD < (1 << PDRSHIFT) 778 testl $PG_G, R(pgeflag) 779 jz 1f 780 ALLOCPAGES(1) 781 movl %esi, %edi 782 movl R(IdlePTD), %eax 783 movl (%eax), %esi 784 movl %edi, (%eax) 785 movl $PAGE_SIZE, %ecx 786 cld 787 rep 788 movsb 789 1: 790 #endif 791 792 /* 793 * For the non-PSE case, install PDEs for PTs covering the KVA. 794 * For the PSE case, do the same, but clobber the ones corresponding 795 * to the kernel (from btext to KERNend) with 4M (2M for PAE) ('PS') 796 * PDEs immediately after. 797 */ 798 movl R(KPTphys), %eax 799 movl $KPTDI, %ebx 800 movl $NKPT, %ecx 801 fillkpt(R(IdlePTD), $PG_RW) 802 cmpl $0,R(pseflag) 803 je done_pde 804 805 movl R(KERNend), %ecx 806 movl $KERNLOAD, %eax 807 subl %eax, %ecx 808 shrl $PDRSHIFT, %ecx 809 movl $(KPTDI+(KERNLOAD/(1 << PDRSHIFT))), %ebx 810 shll $PDESHIFT, %ebx 811 addl R(IdlePTD), %ebx 812 orl $(PG_V|PG_RW|PG_PS), %eax 813 1: movl %eax, (%ebx) 814 addl $(1 << PDRSHIFT), %eax 815 addl $PDESIZE, %ebx 816 loop 1b 817 818 done_pde: 819 /* install a pde recursively mapping page directory as a page table */ 820 movl R(IdlePTD), %eax 821 movl $PTDPTDI, %ebx 822 movl $NPGPTD,%ecx 823 fillkpt(R(IdlePTD), $PG_RW) 824 825 #if defined(PAE) || defined(PAE_TABLES) 826 movl R(IdlePTD), %eax 827 xorl %ebx, %ebx 828 movl $NPGPTD, %ecx 829 fillkpt(R(IdlePDPT), $0x0) 830 #endif 831 832 ret 833 834 #ifdef XENHVM 835 /* Xen Hypercall page */ 836 .text 837 .p2align PAGE_SHIFT, 0x90 /* Hypercall_page needs to be PAGE aligned */ 838 839 NON_GPROF_ENTRY(hypercall_page) 840 .skip 0x1000, 0x90 /* Fill with "nop"s */ 841 #endif
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