locore.s revision 73017
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 73017 2001-02-25 07:44:39Z 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_nfsroot.h" 48 49#include <sys/syscall.h> 50#include <sys/reboot.h> 51 52#include <machine/asmacros.h> 53#include <machine/cputypes.h> 54#include <machine/psl.h> 55#include <machine/pmap.h> 56#include <machine/specialreg.h> 57 58#include "assym.s" 59 60#ifdef __AOUT__ 61#define etext _etext 62#define edata _edata 63#define end _end 64#endif 65 66/* 67 * XXX 68 * 69 * Note: This version greatly munged to avoid various assembler errors 70 * that may be fixed in newer versions of gas. Perhaps newer versions 71 * will have more pleasant appearance. 72 */ 73 74/* 75 * PTmap is recursive pagemap at top of virtual address space. 76 * Within PTmap, the page directory can be found (third indirection). 77 */ 78 .globl PTmap,PTD,PTDpde 79 .set PTmap,(PTDPTDI << PDRSHIFT) 80 .set PTD,PTmap + (PTDPTDI * PAGE_SIZE) 81 .set PTDpde,PTD + (PTDPTDI * PDESIZE) 82 83/* 84 * APTmap, APTD is the alternate recursive pagemap. 85 * It's used when modifying another process's page tables. 86 */ 87 .globl APTmap,APTD,APTDpde 88 .set APTmap,APTDPTDI << PDRSHIFT 89 .set APTD,APTmap + (APTDPTDI * PAGE_SIZE) 90 .set APTDpde,PTD + (APTDPTDI * PDESIZE) 91 92#ifdef SMP 93/* 94 * Define layout of per-cpu address space. 95 * This is "constructed" in locore.s on the BSP and in mp_machdep.c 96 * for each AP. DO NOT REORDER THESE WITHOUT UPDATING THE REST! 97 */ 98 .globl SMP_prvspace, lapic 99 .set SMP_prvspace,(MPPTDI << PDRSHIFT) 100 .set lapic,SMP_prvspace + (NPTEPG-1) * PAGE_SIZE 101#endif /* SMP */ 102 103/* 104 * Globals 105 */ 106 .data 107 ALIGN_DATA /* just to be sure */ 108 109 .globl HIDENAME(tmpstk) 110 .space 0x2000 /* space for tmpstk - temporary stack */ 111HIDENAME(tmpstk): 112 113 .globl boothowto,bootdev 114 115 .globl cpu,cpu_vendor,cpu_id,bootinfo 116 .globl cpu_high, cpu_feature 117 118cpu: .long 0 /* are we 386, 386sx, or 486 */ 119cpu_id: .long 0 /* stepping ID */ 120cpu_high: .long 0 /* highest arg to CPUID */ 121cpu_feature: .long 0 /* features */ 122cpu_vendor: .space 20 /* CPU origin code */ 123bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 124 125KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 126physfree: .long 0 /* phys addr of next free page */ 127 128#ifdef SMP 129 .globl cpu0prvpage 130cpu0pp: .long 0 /* phys addr cpu0 private pg */ 131cpu0prvpage: .long 0 /* relocated version */ 132 133 .globl SMPpt 134SMPptpa: .long 0 /* phys addr SMP page table */ 135SMPpt: .long 0 /* relocated version */ 136#endif /* SMP */ 137 138 .globl IdlePTD 139IdlePTD: .long 0 /* phys addr of kernel PTD */ 140 141#ifdef SMP 142 .globl KPTphys 143#endif 144KPTphys: .long 0 /* phys addr of kernel page tables */ 145 146 .globl proc0paddr 147proc0paddr: .long 0 /* address of proc 0 address space */ 148p0upa: .long 0 /* phys addr of proc0's UPAGES */ 149 150vm86phystk: .long 0 /* PA of vm86/bios stack */ 151 152 .globl vm86paddr, vm86pa 153vm86paddr: .long 0 /* address of vm86 region */ 154vm86pa: .long 0 /* phys addr of vm86 region */ 155 156#ifdef BDE_DEBUGGER 157 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 158_bdb_exists: .long 0 159#endif 160 161#ifdef PC98 162 .globl pc98_system_parameter 163pc98_system_parameter: 164 .space 0x240 165#endif 166 167/********************************************************************** 168 * 169 * Some handy macros 170 * 171 */ 172 173#define R(foo) ((foo)-KERNBASE) 174 175#define ALLOCPAGES(foo) \ 176 movl R(physfree), %esi ; \ 177 movl $((foo)*PAGE_SIZE), %eax ; \ 178 addl %esi, %eax ; \ 179 movl %eax, R(physfree) ; \ 180 movl %esi, %edi ; \ 181 movl $((foo)*PAGE_SIZE),%ecx ; \ 182 xorl %eax,%eax ; \ 183 cld ; \ 184 rep ; \ 185 stosb 186 187/* 188 * fillkpt 189 * eax = page frame address 190 * ebx = index into page table 191 * ecx = how many pages to map 192 * base = base address of page dir/table 193 * prot = protection bits 194 */ 195#define fillkpt(base, prot) \ 196 shll $2,%ebx ; \ 197 addl base,%ebx ; \ 198 orl $PG_V,%eax ; \ 199 orl prot,%eax ; \ 2001: movl %eax,(%ebx) ; \ 201 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 202 addl $4,%ebx ; /* next pte */ \ 203 loop 1b 204 205/* 206 * fillkptphys(prot) 207 * eax = physical address 208 * ecx = how many pages to map 209 * prot = protection bits 210 */ 211#define fillkptphys(prot) \ 212 movl %eax, %ebx ; \ 213 shrl $PAGE_SHIFT, %ebx ; \ 214 fillkpt(R(KPTphys), prot) 215 216 .text 217/********************************************************************** 218 * 219 * This is where the bootblocks start us, set the ball rolling... 220 * 221 */ 222NON_GPROF_ENTRY(btext) 223 224#ifdef PC98 225 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 226 movl $0xa1400,%esi 227 movl $R(pc98_system_parameter),%edi 228 movl $0x0240,%ecx 229 cld 230 rep 231 movsb 232#else /* IBM-PC */ 233#ifdef BDE_DEBUGGER 234#ifdef BIOS_STEALS_3K 235 cmpl $0x0375c339,0x95504 236#else 237 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 238#endif 239 jne 1f 240 movb $1,R(_bdb_exists) 2411: 242#endif 243/* Tell the bios to warmboot next time */ 244 movw $0x1234,0x472 245#endif /* PC98 */ 246 247/* Set up a real frame in case the double return in newboot is executed. */ 248 pushl %ebp 249 movl %esp, %ebp 250 251/* Don't trust what the BIOS gives for eflags. */ 252 pushl $PSL_KERNEL 253 popfl 254 255/* 256 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 257 * to set %cs, %ds, %es and %ss. 258 */ 259 mov %ds, %ax 260 mov %ax, %fs 261 mov %ax, %gs 262 263 call recover_bootinfo 264 265/* Get onto a stack that we can trust. */ 266/* 267 * XXX this step is delayed in case recover_bootinfo needs to return via 268 * the old stack, but it need not be, since recover_bootinfo actually 269 * returns via the old frame. 270 */ 271 movl $R(HIDENAME(tmpstk)),%esp 272 273#ifdef PC98 274 /* pc98_machine_type & M_EPSON_PC98 */ 275 testb $0x02,R(pc98_system_parameter)+220 276 jz 3f 277 /* epson_machine_id <= 0x0b */ 278 cmpb $0x0b,R(pc98_system_parameter)+224 279 ja 3f 280 281 /* count up memory */ 282 movl $0x100000,%eax /* next, talley remaining memory */ 283 movl $0xFFF-0x100,%ecx 2841: movl 0(%eax),%ebx /* save location to check */ 285 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 286 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 287 jne 2f 288 movl %ebx,0(%eax) /* restore memory */ 289 addl $PAGE_SIZE,%eax 290 loop 1b 2912: subl $0x100000,%eax 292 shrl $17,%eax 293 movb %al,R(pc98_system_parameter)+1 2943: 295 296 movw R(pc98_system_parameter+0x86),%ax 297 movw %ax,R(cpu_id) 298#endif 299 300 call identify_cpu 301 302/* clear bss */ 303/* 304 * XXX this should be done a little earlier. 305 * 306 * XXX we don't check that there is memory for our bss and page tables 307 * before using it. 308 * 309 * XXX the boot program somewhat bogusly clears the bss. We still have 310 * to do it in case we were unzipped by kzipboot. Then the boot program 311 * only clears kzipboot's bss. 312 * 313 * XXX the gdt and idt are still somewhere in the boot program. We 314 * depend on the convention that the boot program is below 1MB and we 315 * are above 1MB to keep the gdt and idt away from the bss and page 316 * tables. The idt is only used if BDE_DEBUGGER is enabled. 317 */ 318 movl $R(end),%ecx 319 movl $R(edata),%edi 320 subl %edi,%ecx 321 xorl %eax,%eax 322 cld 323 rep 324 stosb 325 326 call create_pagetables 327 328/* 329 * If the CPU has support for VME, turn it on. 330 */ 331 testl $CPUID_VME, R(cpu_feature) 332 jz 1f 333 movl %cr4, %eax 334 orl $CR4_VME, %eax 335 movl %eax, %cr4 3361: 337 338#ifdef BDE_DEBUGGER 339/* 340 * Adjust as much as possible for paging before enabling paging so that the 341 * adjustments can be traced. 342 */ 343 call bdb_prepare_paging 344#endif 345 346/* Now enable paging */ 347 movl R(IdlePTD), %eax 348 movl %eax,%cr3 /* load ptd addr into mmu */ 349 movl %cr0,%eax /* get control word */ 350 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 351 movl %eax,%cr0 /* and let's page NOW! */ 352 353#ifdef BDE_DEBUGGER 354/* 355 * Complete the adjustments for paging so that we can keep tracing through 356 * initi386() after the low (physical) addresses for the gdt and idt become 357 * invalid. 358 */ 359 call bdb_commit_paging 360#endif 361 362 pushl $begin /* jump to high virtualized address */ 363 ret 364 365/* now running relocated at KERNBASE where the system is linked to run */ 366begin: 367 /* set up bootstrap stack */ 368 movl proc0paddr,%eax /* location of in-kernel pages */ 369 leal UPAGES*PAGE_SIZE(%eax),%esp /* bootstrap stack end location */ 370 371 xorl %ebp,%ebp /* mark end of frames */ 372 373 movl IdlePTD,%esi 374 movl %esi,PCB_CR3(%eax) 375 376 pushl physfree /* value of first for init386(first) */ 377 call init386 /* wire 386 chip for unix operation */ 378 379 /* 380 * Clean up the stack in a way that db_numargs() understands, so 381 * that backtraces in ddb don't underrun the stack. Traps for 382 * inaccessible memory are more fatal than usual this early. 383 */ 384 addl $4,%esp 385 386 call mi_startup /* autoconfiguration, mountroot etc */ 387 /* NOTREACHED */ 388 addl $0,%esp /* for db_numargs() again */ 389 390/* 391 * Signal trampoline, copied to top of user stack 392 */ 393NON_GPROF_ENTRY(sigcode) 394 call *SIGF_HANDLER(%esp) /* call signal handler */ 395 lea SIGF_UC(%esp),%eax /* get ucontext_t */ 396 pushl %eax 397 testl $PSL_VM,UC_EFLAGS(%eax) 398 jne 9f 399 movl UC_GS(%eax),%gs /* restore %gs */ 4009: 401 movl $SYS_sigreturn,%eax 402 pushl %eax /* junk to fake return addr. */ 403 int $0x80 /* enter kernel with args */ 4040: jmp 0b 405 406 ALIGN_TEXT 407osigcode: 408 call *SIGF_HANDLER(%esp) /* call signal handler */ 409 lea SIGF_SC(%esp),%eax /* get sigcontext */ 410 pushl %eax 411 testl $PSL_VM,SC_PS(%eax) 412 jne 9f 413 movl SC_GS(%eax),%gs /* restore %gs */ 4149: 415 movl $0x01d516,SC_TRAPNO(%eax) /* magic: 0ldSiG */ 416 movl $SYS_sigreturn,%eax 417 pushl %eax /* junk to fake return addr. */ 418 int $0x80 /* enter kernel with args */ 4190: jmp 0b 420 421 ALIGN_TEXT 422esigcode: 423 424 .data 425 .globl szsigcode, szosigcode 426szsigcode: 427 .long esigcode-sigcode 428szosigcode: 429 .long esigcode-osigcode 430 .text 431 432/********************************************************************** 433 * 434 * Recover the bootinfo passed to us from the boot program 435 * 436 */ 437recover_bootinfo: 438 /* 439 * This code is called in different ways depending on what loaded 440 * and started the kernel. This is used to detect how we get the 441 * arguments from the other code and what we do with them. 442 * 443 * Old disk boot blocks: 444 * (*btext)(howto, bootdev, cyloffset, esym); 445 * [return address == 0, and can NOT be returned to] 446 * [cyloffset was not supported by the FreeBSD boot code 447 * and always passed in as 0] 448 * [esym is also known as total in the boot code, and 449 * was never properly supported by the FreeBSD boot code] 450 * 451 * Old diskless netboot code: 452 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 453 * [return address != 0, and can NOT be returned to] 454 * If we are being booted by this code it will NOT work, 455 * so we are just going to halt if we find this case. 456 * 457 * New uniform boot code: 458 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 459 * [return address != 0, and can be returned to] 460 * 461 * There may seem to be a lot of wasted arguments in here, but 462 * that is so the newer boot code can still load very old kernels 463 * and old boot code can load new kernels. 464 */ 465 466 /* 467 * The old style disk boot blocks fake a frame on the stack and 468 * did an lret to get here. The frame on the stack has a return 469 * address of 0. 470 */ 471 cmpl $0,4(%ebp) 472 je olddiskboot 473 474 /* 475 * We have some form of return address, so this is either the 476 * old diskless netboot code, or the new uniform code. That can 477 * be detected by looking at the 5th argument, if it is 0 478 * we are being booted by the new uniform boot code. 479 */ 480 cmpl $0,24(%ebp) 481 je newboot 482 483 /* 484 * Seems we have been loaded by the old diskless boot code, we 485 * don't stand a chance of running as the diskless structure 486 * changed considerably between the two, so just halt. 487 */ 488 hlt 489 490 /* 491 * We have been loaded by the new uniform boot code. 492 * Let's check the bootinfo version, and if we do not understand 493 * it we return to the loader with a status of 1 to indicate this error 494 */ 495newboot: 496 movl 28(%ebp),%ebx /* &bootinfo.version */ 497 movl BI_VERSION(%ebx),%eax 498 cmpl $1,%eax /* We only understand version 1 */ 499 je 1f 500 movl $1,%eax /* Return status */ 501 leave 502 /* 503 * XXX this returns to our caller's caller (as is required) since 504 * we didn't set up a frame and our caller did. 505 */ 506 ret 507 5081: 509 /* 510 * If we have a kernelname copy it in 511 */ 512 movl BI_KERNELNAME(%ebx),%esi 513 cmpl $0,%esi 514 je 2f /* No kernelname */ 515 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 516 movl $R(kernelname),%edi 517 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 518 je 1f 519 movb $'/',(%edi) 520 incl %edi 521 decl %ecx 5221: 523 cld 524 rep 525 movsb 526 5272: 528 /* 529 * Determine the size of the boot loader's copy of the bootinfo 530 * struct. This is impossible to do properly because old versions 531 * of the struct don't contain a size field and there are 2 old 532 * versions with the same version number. 533 */ 534 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 535 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 536 je got_bi_size /* no, sizeless version */ 537 movl BI_SIZE(%ebx),%ecx 538got_bi_size: 539 540 /* 541 * Copy the common part of the bootinfo struct 542 */ 543 movl %ebx,%esi 544 movl $R(bootinfo),%edi 545 cmpl $BOOTINFO_SIZE,%ecx 546 jbe got_common_bi_size 547 movl $BOOTINFO_SIZE,%ecx 548got_common_bi_size: 549 cld 550 rep 551 movsb 552 553#ifdef NFS_ROOT 554#ifndef BOOTP_NFSV3 555 /* 556 * If we have a nfs_diskless structure copy it in 557 */ 558 movl BI_NFS_DISKLESS(%ebx),%esi 559 cmpl $0,%esi 560 je olddiskboot 561 movl $R(nfs_diskless),%edi 562 movl $NFSDISKLESS_SIZE,%ecx 563 cld 564 rep 565 movsb 566 movl $R(nfs_diskless_valid),%edi 567 movl $1,(%edi) 568#endif 569#endif 570 571 /* 572 * The old style disk boot. 573 * (*btext)(howto, bootdev, cyloffset, esym); 574 * Note that the newer boot code just falls into here to pick 575 * up howto and bootdev, cyloffset and esym are no longer used 576 */ 577olddiskboot: 578 movl 8(%ebp),%eax 579 movl %eax,R(boothowto) 580 movl 12(%ebp),%eax 581 movl %eax,R(bootdev) 582 583 ret 584 585 586/********************************************************************** 587 * 588 * Identify the CPU and initialize anything special about it 589 * 590 */ 591identify_cpu: 592 593 /* Try to toggle alignment check flag; does not exist on 386. */ 594 pushfl 595 popl %eax 596 movl %eax,%ecx 597 orl $PSL_AC,%eax 598 pushl %eax 599 popfl 600 pushfl 601 popl %eax 602 xorl %ecx,%eax 603 andl $PSL_AC,%eax 604 pushl %ecx 605 popfl 606 607 testl %eax,%eax 608 jnz try486 609 610 /* NexGen CPU does not have aligment check flag. */ 611 pushfl 612 movl $0x5555, %eax 613 xorl %edx, %edx 614 movl $2, %ecx 615 clc 616 divl %ecx 617 jz trynexgen 618 popfl 619 movl $CPU_386,R(cpu) 620 jmp 3f 621 622trynexgen: 623 popfl 624 movl $CPU_NX586,R(cpu) 625 movl $0x4778654e,R(cpu_vendor) # store vendor string 626 movl $0x72446e65,R(cpu_vendor+4) 627 movl $0x6e657669,R(cpu_vendor+8) 628 movl $0,R(cpu_vendor+12) 629 jmp 3f 630 631try486: /* Try to toggle identification flag; does not exist on early 486s. */ 632 pushfl 633 popl %eax 634 movl %eax,%ecx 635 xorl $PSL_ID,%eax 636 pushl %eax 637 popfl 638 pushfl 639 popl %eax 640 xorl %ecx,%eax 641 andl $PSL_ID,%eax 642 pushl %ecx 643 popfl 644 645 testl %eax,%eax 646 jnz trycpuid 647 movl $CPU_486,R(cpu) 648 649 /* 650 * Check Cyrix CPU 651 * Cyrix CPUs do not change the undefined flags following 652 * execution of the divide instruction which divides 5 by 2. 653 * 654 * Note: CPUID is enabled on M2, so it passes another way. 655 */ 656 pushfl 657 movl $0x5555, %eax 658 xorl %edx, %edx 659 movl $2, %ecx 660 clc 661 divl %ecx 662 jnc trycyrix 663 popfl 664 jmp 3f /* You may use Intel CPU. */ 665 666trycyrix: 667 popfl 668 /* 669 * IBM Bluelighting CPU also doesn't change the undefined flags. 670 * Because IBM doesn't disclose the information for Bluelighting 671 * CPU, we couldn't distinguish it from Cyrix's (including IBM 672 * brand of Cyrix CPUs). 673 */ 674 movl $0x69727943,R(cpu_vendor) # store vendor string 675 movl $0x736e4978,R(cpu_vendor+4) 676 movl $0x64616574,R(cpu_vendor+8) 677 jmp 3f 678 679trycpuid: /* Use the `cpuid' instruction. */ 680 xorl %eax,%eax 681 cpuid # cpuid 0 682 movl %eax,R(cpu_high) # highest capability 683 movl %ebx,R(cpu_vendor) # store vendor string 684 movl %edx,R(cpu_vendor+4) 685 movl %ecx,R(cpu_vendor+8) 686 movb $0,R(cpu_vendor+12) 687 688 movl $1,%eax 689 cpuid # cpuid 1 690 movl %eax,R(cpu_id) # store cpu_id 691 movl %edx,R(cpu_feature) # store cpu_feature 692 rorl $8,%eax # extract family type 693 andl $15,%eax 694 cmpl $5,%eax 695 jae 1f 696 697 /* less than Pentium; must be 486 */ 698 movl $CPU_486,R(cpu) 699 jmp 3f 7001: 701 /* a Pentium? */ 702 cmpl $5,%eax 703 jne 2f 704 movl $CPU_586,R(cpu) 705 jmp 3f 7062: 707 /* Greater than Pentium...call it a Pentium Pro */ 708 movl $CPU_686,R(cpu) 7093: 710 ret 711 712 713/********************************************************************** 714 * 715 * Create the first page directory and its page tables. 716 * 717 */ 718 719create_pagetables: 720 721 testl $CPUID_PGE, R(cpu_feature) 722 jz 1f 723 movl %cr4, %eax 724 orl $CR4_PGE, %eax 725 movl %eax, %cr4 7261: 727 728/* Find end of kernel image (rounded up to a page boundary). */ 729 movl $R(_end),%esi 730 731/* Include symbols, if any. */ 732 movl R(bootinfo+BI_ESYMTAB),%edi 733 testl %edi,%edi 734 je over_symalloc 735 movl %edi,%esi 736 movl $KERNBASE,%edi 737 addl %edi,R(bootinfo+BI_SYMTAB) 738 addl %edi,R(bootinfo+BI_ESYMTAB) 739over_symalloc: 740 741/* If we are told where the end of the kernel space is, believe it. */ 742 movl R(bootinfo+BI_KERNEND),%edi 743 testl %edi,%edi 744 je no_kernend 745 movl %edi,%esi 746no_kernend: 747 748 addl $PAGE_MASK,%esi 749 andl $~PAGE_MASK,%esi 750 movl %esi,R(KERNend) /* save end of kernel */ 751 movl %esi,R(physfree) /* next free page is at end of kernel */ 752 753/* Allocate Kernel Page Tables */ 754 ALLOCPAGES(NKPT) 755 movl %esi,R(KPTphys) 756 757/* Allocate Page Table Directory */ 758 ALLOCPAGES(1) 759 movl %esi,R(IdlePTD) 760 761/* Allocate UPAGES */ 762 ALLOCPAGES(UPAGES) 763 movl %esi,R(p0upa) 764 addl $KERNBASE, %esi 765 movl %esi, R(proc0paddr) 766 767 ALLOCPAGES(1) /* vm86/bios stack */ 768 movl %esi,R(vm86phystk) 769 770 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 771 movl %esi,R(vm86pa) 772 addl $KERNBASE, %esi 773 movl %esi, R(vm86paddr) 774 775#ifdef SMP 776/* Allocate cpu0's private data page */ 777 ALLOCPAGES(1) 778 movl %esi,R(cpu0pp) 779 addl $KERNBASE, %esi 780 movl %esi, R(cpu0prvpage) /* relocated to KVM space */ 781 782/* Allocate SMP page table page */ 783 ALLOCPAGES(1) 784 movl %esi,R(SMPptpa) 785 addl $KERNBASE, %esi 786 movl %esi, R(SMPpt) /* relocated to KVM space */ 787#endif /* SMP */ 788 789/* Map read-only from zero to the end of the kernel text section */ 790 xorl %eax, %eax 791#ifdef BDE_DEBUGGER 792/* If the debugger is present, actually map everything read-write. */ 793 cmpl $0,R(_bdb_exists) 794 jne map_read_write 795#endif 796 xorl %edx,%edx 797 798#if !defined(SMP) 799 testl $CPUID_PGE, R(cpu_feature) 800 jz 2f 801 orl $PG_G,%edx 802#endif 803 8042: movl $R(etext),%ecx 805 addl $PAGE_MASK,%ecx 806 shrl $PAGE_SHIFT,%ecx 807 fillkptphys(%edx) 808 809/* Map read-write, data, bss and symbols */ 810 movl $R(etext),%eax 811 addl $PAGE_MASK, %eax 812 andl $~PAGE_MASK, %eax 813map_read_write: 814 movl $PG_RW,%edx 815#if !defined(SMP) 816 testl $CPUID_PGE, R(cpu_feature) 817 jz 1f 818 orl $PG_G,%edx 819#endif 820 8211: movl R(KERNend),%ecx 822 subl %eax,%ecx 823 shrl $PAGE_SHIFT,%ecx 824 fillkptphys(%edx) 825 826/* Map page directory. */ 827 movl R(IdlePTD), %eax 828 movl $1, %ecx 829 fillkptphys($PG_RW) 830 831/* Map proc0's UPAGES in the physical way ... */ 832 movl R(p0upa), %eax 833 movl $UPAGES, %ecx 834 fillkptphys($PG_RW) 835 836/* Map ISA hole */ 837 movl $ISA_HOLE_START, %eax 838 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 839 fillkptphys($PG_RW) 840 841/* Map space for the vm86 region */ 842 movl R(vm86phystk), %eax 843 movl $4, %ecx 844 fillkptphys($PG_RW) 845 846/* Map page 0 into the vm86 page table */ 847 movl $0, %eax 848 movl $0, %ebx 849 movl $1, %ecx 850 fillkpt(R(vm86pa), $PG_RW|PG_U) 851 852/* ...likewise for the ISA hole */ 853 movl $ISA_HOLE_START, %eax 854 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 855 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 856 fillkpt(R(vm86pa), $PG_RW|PG_U) 857 858#ifdef SMP 859/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 860 movl R(cpu0pp), %eax 861 movl $1, %ecx 862 fillkptphys($PG_RW) 863 864/* Map SMP page table page into global kmem FWIW */ 865 movl R(SMPptpa), %eax 866 movl $1, %ecx 867 fillkptphys($PG_RW) 868 869/* Map the private page into the SMP page table */ 870 movl R(cpu0pp), %eax 871 movl $0, %ebx /* pte offset = 0 */ 872 movl $1, %ecx /* one private page coming right up */ 873 fillkpt(R(SMPptpa), $PG_RW) 874 875/* ... and put the page table table in the pde. */ 876 movl R(SMPptpa), %eax 877 movl $MPPTDI, %ebx 878 movl $1, %ecx 879 fillkpt(R(IdlePTD), $PG_RW) 880 881/* Fakeup VA for the local apic to allow early traps. */ 882 ALLOCPAGES(1) 883 movl %esi, %eax 884 movl $(NPTEPG-1), %ebx /* pte offset = NTEPG-1 */ 885 movl $1, %ecx /* one private pt coming right up */ 886 fillkpt(R(SMPptpa), $PG_RW) 887#endif /* SMP */ 888 889/* install a pde for temporary double map of bottom of VA */ 890 movl R(KPTphys), %eax 891 xorl %ebx, %ebx 892 movl $1, %ecx 893 fillkpt(R(IdlePTD), $PG_RW) 894 895/* install pde's for pt's */ 896 movl R(KPTphys), %eax 897 movl $KPTDI, %ebx 898 movl $NKPT, %ecx 899 fillkpt(R(IdlePTD), $PG_RW) 900 901/* install a pde recursively mapping page directory as a page table */ 902 movl R(IdlePTD), %eax 903 movl $PTDPTDI, %ebx 904 movl $1,%ecx 905 fillkpt(R(IdlePTD), $PG_RW) 906 907 ret 908 909#ifdef BDE_DEBUGGER 910bdb_prepare_paging: 911 cmpl $0,R(_bdb_exists) 912 je bdb_prepare_paging_exit 913 914 subl $6,%esp 915 916 /* 917 * Copy and convert debugger entries from the bootstrap gdt and idt 918 * to the kernel gdt and idt. Everything is still in low memory. 919 * Tracing continues to work after paging is enabled because the 920 * low memory addresses remain valid until everything is relocated. 921 * However, tracing through the setidt() that initializes the trace 922 * trap will crash. 923 */ 924 sgdt (%esp) 925 movl 2(%esp),%esi /* base address of bootstrap gdt */ 926 movl $R(_gdt),%edi 927 movl %edi,2(%esp) /* prepare to load kernel gdt */ 928 movl $8*18/4,%ecx 929 cld 930 rep /* copy gdt */ 931 movsl 932 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 933 movb $0x92,-8+5(%edi) 934 lgdt (%esp) 935 936 sidt (%esp) 937 movl 2(%esp),%esi /* base address of current idt */ 938 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 939 movw 8(%esi),%ax 940 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 941 movl 8+2(%esi),%eax 942 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 943 movl 24+4(%esi),%eax /* same for bpt descriptor */ 944 movw 24(%esi),%ax 945 movl %eax,R(bdb_bpt_ljmp+1) 946 movl 24+2(%esi),%eax 947 movw %ax,R(bdb_bpt_ljmp+5) 948 movl R(_idt),%edi 949 movl %edi,2(%esp) /* prepare to load kernel idt */ 950 movl $8*4/4,%ecx 951 cld 952 rep /* copy idt */ 953 movsl 954 lidt (%esp) 955 956 addl $6,%esp 957 958bdb_prepare_paging_exit: 959 ret 960 961/* Relocate debugger gdt entries and gdt and idt pointers. */ 962bdb_commit_paging: 963 cmpl $0,_bdb_exists 964 je bdb_commit_paging_exit 965 966 movl $gdt+8*9,%eax /* adjust slots 9-17 */ 967 movl $9,%ecx 968reloc_gdt: 969 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 970 addl $8,%eax /* now KERNBASE>>24 */ 971 loop reloc_gdt 972 973 subl $6,%esp 974 sgdt (%esp) 975 addl $KERNBASE,2(%esp) 976 lgdt (%esp) 977 sidt (%esp) 978 addl $KERNBASE,2(%esp) 979 lidt (%esp) 980 addl $6,%esp 981 982 int $3 983 984bdb_commit_paging_exit: 985 ret 986 987#endif /* BDE_DEBUGGER */ 988