locore.s revision 83366
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 83366 2001-09-12 08:38:13Z julian $ 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 * NOTE: PTDpde, PTmap, and PTD are being defined as address symbols. 79 * In C you access them directly, and not with a '*'. Storage is not being 80 * allocated. They will magically address the correct locations in KVM 81 * which C will treat as normal variables of the type they are defined in 82 * machine/pmap.h, i.e. PTDpde = XX ; to set a PDE entry, NOT *PTDpde = XX; 83 */ 84 .globl PTmap,PTD,PTDpde 85 .set PTmap,(PTDPTDI << PDRSHIFT) 86 .set PTD,PTmap + (PTDPTDI * PAGE_SIZE) 87 .set PTDpde,PTD + (PTDPTDI * PDESIZE) 88 89/* 90 * APTmap, APTD is the alternate recursive pagemap. 91 * It's used when modifying another process's page tables. 92 * See the note above. It is true here as well. 93 */ 94 .globl APTmap,APTD,APTDpde 95 .set APTmap,APTDPTDI << PDRSHIFT 96 .set APTD,APTmap + (APTDPTDI * PAGE_SIZE) 97 .set APTDpde,PTD + (APTDPTDI * PDESIZE) 98 99#ifdef SMP 100/* 101 * Define layout of per-cpu address space. 102 * This is "constructed" in locore.s on the BSP and in mp_machdep.c 103 * for each AP. DO NOT REORDER THESE WITHOUT UPDATING THE REST! 104 */ 105 .globl SMP_prvspace, lapic 106 .set SMP_prvspace,(MPPTDI << PDRSHIFT) 107 .set lapic,SMP_prvspace + (NPTEPG-1) * PAGE_SIZE 108#endif /* SMP */ 109 110/* 111 * Compiled KERNBASE location 112 */ 113 .globl kernbase 114 .set kernbase,KERNBASE 115 116/* 117 * Globals 118 */ 119 .data 120 ALIGN_DATA /* just to be sure */ 121 122 .globl HIDENAME(tmpstk) 123 .space 0x2000 /* space for tmpstk - temporary stack */ 124HIDENAME(tmpstk): 125 126 .globl bootinfo 127bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 128 129KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 130physfree: .long 0 /* phys addr of next free page */ 131 132#ifdef SMP 133 .globl cpu0prvpage 134cpu0pp: .long 0 /* phys addr cpu0 private pg */ 135cpu0prvpage: .long 0 /* relocated version */ 136 137 .globl SMPpt 138SMPptpa: .long 0 /* phys addr SMP page table */ 139SMPpt: .long 0 /* relocated version */ 140#endif /* SMP */ 141 142 .globl IdlePTD 143IdlePTD: .long 0 /* phys addr of kernel PTD */ 144 145#ifdef SMP 146 .globl KPTphys 147#endif 148KPTphys: .long 0 /* phys addr of kernel page tables */ 149 150 .globl proc0uarea, proc0kstack 151proc0uarea: .long 0 /* address of proc 0 uarea space */ 152proc0kstack: .long 0 /* address of proc 0 kstack space */ 153p0upa: .long 0 /* phys addr of proc0's UAREA */ 154p0kpa: .long 0 /* phys addr of proc0's STACK */ 155 156vm86phystk: .long 0 /* PA of vm86/bios stack */ 157 158 .globl vm86paddr, vm86pa 159vm86paddr: .long 0 /* address of vm86 region */ 160vm86pa: .long 0 /* phys addr of vm86 region */ 161 162#ifdef BDE_DEBUGGER 163 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 164_bdb_exists: .long 0 165#endif 166 167#ifdef PC98 168 .globl pc98_system_parameter 169pc98_system_parameter: 170 .space 0x240 171#endif 172 173/********************************************************************** 174 * 175 * Some handy macros 176 * 177 */ 178 179#define R(foo) ((foo)-KERNBASE) 180 181#define ALLOCPAGES(foo) \ 182 movl R(physfree), %esi ; \ 183 movl $((foo)*PAGE_SIZE), %eax ; \ 184 addl %esi, %eax ; \ 185 movl %eax, R(physfree) ; \ 186 movl %esi, %edi ; \ 187 movl $((foo)*PAGE_SIZE),%ecx ; \ 188 xorl %eax,%eax ; \ 189 cld ; \ 190 rep ; \ 191 stosb 192 193/* 194 * fillkpt 195 * eax = page frame address 196 * ebx = index into page table 197 * ecx = how many pages to map 198 * base = base address of page dir/table 199 * prot = protection bits 200 */ 201#define fillkpt(base, prot) \ 202 shll $2,%ebx ; \ 203 addl base,%ebx ; \ 204 orl $PG_V,%eax ; \ 205 orl prot,%eax ; \ 2061: movl %eax,(%ebx) ; \ 207 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 208 addl $4,%ebx ; /* next pte */ \ 209 loop 1b 210 211/* 212 * fillkptphys(prot) 213 * eax = physical address 214 * ecx = how many pages to map 215 * prot = protection bits 216 */ 217#define fillkptphys(prot) \ 218 movl %eax, %ebx ; \ 219 shrl $PAGE_SHIFT, %ebx ; \ 220 fillkpt(R(KPTphys), prot) 221 222 .text 223/********************************************************************** 224 * 225 * This is where the bootblocks start us, set the ball rolling... 226 * 227 */ 228NON_GPROF_ENTRY(btext) 229 230#ifdef PC98 231 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 232 movl $0xa1400,%esi 233 movl $R(pc98_system_parameter),%edi 234 movl $0x0240,%ecx 235 cld 236 rep 237 movsb 238#else /* IBM-PC */ 239#ifdef BDE_DEBUGGER 240#ifdef BIOS_STEALS_3K 241 cmpl $0x0375c339,0x95504 242#else 243 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 244#endif 245 jne 1f 246 movb $1,R(_bdb_exists) 2471: 248#endif 249/* Tell the bios to warmboot next time */ 250 movw $0x1234,0x472 251#endif /* PC98 */ 252 253/* Set up a real frame in case the double return in newboot is executed. */ 254 pushl %ebp 255 movl %esp, %ebp 256 257/* Don't trust what the BIOS gives for eflags. */ 258 pushl $PSL_KERNEL 259 popfl 260 261/* 262 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 263 * to set %cs, %ds, %es and %ss. 264 */ 265 mov %ds, %ax 266 mov %ax, %fs 267 mov %ax, %gs 268 269 call recover_bootinfo 270 271/* Get onto a stack that we can trust. */ 272/* 273 * XXX this step is delayed in case recover_bootinfo needs to return via 274 * the old stack, but it need not be, since recover_bootinfo actually 275 * returns via the old frame. 276 */ 277 movl $R(HIDENAME(tmpstk)),%esp 278 279#ifdef PC98 280 /* pc98_machine_type & M_EPSON_PC98 */ 281 testb $0x02,R(pc98_system_parameter)+220 282 jz 3f 283 /* epson_machine_id <= 0x0b */ 284 cmpb $0x0b,R(pc98_system_parameter)+224 285 ja 3f 286 287 /* count up memory */ 288 movl $0x100000,%eax /* next, talley remaining memory */ 289 movl $0xFFF-0x100,%ecx 2901: movl 0(%eax),%ebx /* save location to check */ 291 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 292 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 293 jne 2f 294 movl %ebx,0(%eax) /* restore memory */ 295 addl $PAGE_SIZE,%eax 296 loop 1b 2972: subl $0x100000,%eax 298 shrl $17,%eax 299 movb %al,R(pc98_system_parameter)+1 3003: 301 302 movw R(pc98_system_parameter+0x86),%ax 303 movw %ax,R(cpu_id) 304#endif 305 306 call identify_cpu 307 308/* clear bss */ 309/* 310 * XXX this should be done a little earlier. 311 * 312 * XXX we don't check that there is memory for our bss and page tables 313 * before using it. 314 * 315 * XXX the boot program somewhat bogusly clears the bss. We still have 316 * to do it in case we were unzipped by kzipboot. Then the boot program 317 * only clears kzipboot's bss. 318 * 319 * XXX the gdt and idt are still somewhere in the boot program. We 320 * depend on the convention that the boot program is below 1MB and we 321 * are above 1MB to keep the gdt and idt away from the bss and page 322 * tables. The idt is only used if BDE_DEBUGGER is enabled. 323 */ 324 movl $R(end),%ecx 325 movl $R(edata),%edi 326 subl %edi,%ecx 327 xorl %eax,%eax 328 cld 329 rep 330 stosb 331 332 call create_pagetables 333 334/* 335 * If the CPU has support for VME, turn it on. 336 */ 337 testl $CPUID_VME, R(cpu_feature) 338 jz 1f 339 movl %cr4, %eax 340 orl $CR4_VME, %eax 341 movl %eax, %cr4 3421: 343 344#ifdef BDE_DEBUGGER 345/* 346 * Adjust as much as possible for paging before enabling paging so that the 347 * adjustments can be traced. 348 */ 349 call bdb_prepare_paging 350#endif 351 352/* Now enable paging */ 353 movl R(IdlePTD), %eax 354 movl %eax,%cr3 /* load ptd addr into mmu */ 355 movl %cr0,%eax /* get control word */ 356 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 357 movl %eax,%cr0 /* and let's page NOW! */ 358 359#ifdef BDE_DEBUGGER 360/* 361 * Complete the adjustments for paging so that we can keep tracing through 362 * initi386() after the low (physical) addresses for the gdt and idt become 363 * invalid. 364 */ 365 call bdb_commit_paging 366#endif 367 368 pushl $begin /* jump to high virtualized address */ 369 ret 370 371/* now running relocated at KERNBASE where the system is linked to run */ 372begin: 373 /* set up bootstrap stack */ 374 movl proc0kstack,%eax /* location of in-kernel stack */ 375 /* bootstrap stack end location */ 376 leal (KSTACK_PAGES*PAGE_SIZE-PCB_SIZE)(%eax),%esp 377 378 xorl %ebp,%ebp /* mark end of frames */ 379 380 movl IdlePTD,%esi 381 movl %esi,(KSTACK_PAGES*PAGE_SIZE-PCB_SIZE+PCB_CR3)(%eax) 382 383 testl $CPUID_PGE, R(cpu_feature) 384 jz 1f 385 movl %cr4, %eax 386 orl $CR4_PGE, %eax 387 movl %eax, %cr4 3881: 389 pushl physfree /* value of first for init386(first) */ 390 call init386 /* wire 386 chip for unix operation */ 391 392 /* 393 * Clean up the stack in a way that db_numargs() understands, so 394 * that backtraces in ddb don't underrun the stack. Traps for 395 * inaccessible memory are more fatal than usual this early. 396 */ 397 addl $4,%esp 398 399 call mi_startup /* autoconfiguration, mountroot etc */ 400 /* NOTREACHED */ 401 addl $0,%esp /* for db_numargs() again */ 402 403/* 404 * Signal trampoline, copied to top of user stack 405 */ 406NON_GPROF_ENTRY(sigcode) 407 call *SIGF_HANDLER(%esp) /* call signal handler */ 408 lea SIGF_UC(%esp),%eax /* get ucontext_t */ 409 pushl %eax 410 testl $PSL_VM,UC_EFLAGS(%eax) 411 jne 9f 412 movl UC_GS(%eax),%gs /* restore %gs */ 4139: 414 movl $SYS_sigreturn,%eax 415 pushl %eax /* junk to fake return addr. */ 416 int $0x80 /* enter kernel with args */ 4170: jmp 0b 418 419 ALIGN_TEXT 420osigcode: 421 call *SIGF_HANDLER(%esp) /* call signal handler */ 422 lea SIGF_SC(%esp),%eax /* get sigcontext */ 423 pushl %eax 424 testl $PSL_VM,SC_PS(%eax) 425 jne 9f 426 movl SC_GS(%eax),%gs /* restore %gs */ 4279: 428 movl $0x01d516,SC_TRAPNO(%eax) /* magic: 0ldSiG */ 429 movl $SYS_sigreturn,%eax 430 pushl %eax /* junk to fake return addr. */ 431 int $0x80 /* enter kernel with args */ 4320: jmp 0b 433 434 ALIGN_TEXT 435esigcode: 436 437 .data 438 .globl szsigcode, szosigcode 439szsigcode: 440 .long esigcode-sigcode 441szosigcode: 442 .long esigcode-osigcode 443 .text 444 445/********************************************************************** 446 * 447 * Recover the bootinfo passed to us from the boot program 448 * 449 */ 450recover_bootinfo: 451 /* 452 * This code is called in different ways depending on what loaded 453 * and started the kernel. This is used to detect how we get the 454 * arguments from the other code and what we do with them. 455 * 456 * Old disk boot blocks: 457 * (*btext)(howto, bootdev, cyloffset, esym); 458 * [return address == 0, and can NOT be returned to] 459 * [cyloffset was not supported by the FreeBSD boot code 460 * and always passed in as 0] 461 * [esym is also known as total in the boot code, and 462 * was never properly supported by the FreeBSD boot code] 463 * 464 * Old diskless netboot code: 465 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 466 * [return address != 0, and can NOT be returned to] 467 * If we are being booted by this code it will NOT work, 468 * so we are just going to halt if we find this case. 469 * 470 * New uniform boot code: 471 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 472 * [return address != 0, and can be returned to] 473 * 474 * There may seem to be a lot of wasted arguments in here, but 475 * that is so the newer boot code can still load very old kernels 476 * and old boot code can load new kernels. 477 */ 478 479 /* 480 * The old style disk boot blocks fake a frame on the stack and 481 * did an lret to get here. The frame on the stack has a return 482 * address of 0. 483 */ 484 cmpl $0,4(%ebp) 485 je olddiskboot 486 487 /* 488 * We have some form of return address, so this is either the 489 * old diskless netboot code, or the new uniform code. That can 490 * be detected by looking at the 5th argument, if it is 0 491 * we are being booted by the new uniform boot code. 492 */ 493 cmpl $0,24(%ebp) 494 je newboot 495 496 /* 497 * Seems we have been loaded by the old diskless boot code, we 498 * don't stand a chance of running as the diskless structure 499 * changed considerably between the two, so just halt. 500 */ 501 hlt 502 503 /* 504 * We have been loaded by the new uniform boot code. 505 * Let's check the bootinfo version, and if we do not understand 506 * it we return to the loader with a status of 1 to indicate this error 507 */ 508newboot: 509 movl 28(%ebp),%ebx /* &bootinfo.version */ 510 movl BI_VERSION(%ebx),%eax 511 cmpl $1,%eax /* We only understand version 1 */ 512 je 1f 513 movl $1,%eax /* Return status */ 514 leave 515 /* 516 * XXX this returns to our caller's caller (as is required) since 517 * we didn't set up a frame and our caller did. 518 */ 519 ret 520 5211: 522 /* 523 * If we have a kernelname copy it in 524 */ 525 movl BI_KERNELNAME(%ebx),%esi 526 cmpl $0,%esi 527 je 2f /* No kernelname */ 528 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 529 movl $R(kernelname),%edi 530 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 531 je 1f 532 movb $'/',(%edi) 533 incl %edi 534 decl %ecx 5351: 536 cld 537 rep 538 movsb 539 5402: 541 /* 542 * Determine the size of the boot loader's copy of the bootinfo 543 * struct. This is impossible to do properly because old versions 544 * of the struct don't contain a size field and there are 2 old 545 * versions with the same version number. 546 */ 547 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 548 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 549 je got_bi_size /* no, sizeless version */ 550 movl BI_SIZE(%ebx),%ecx 551got_bi_size: 552 553 /* 554 * Copy the common part of the bootinfo struct 555 */ 556 movl %ebx,%esi 557 movl $R(bootinfo),%edi 558 cmpl $BOOTINFO_SIZE,%ecx 559 jbe got_common_bi_size 560 movl $BOOTINFO_SIZE,%ecx 561got_common_bi_size: 562 cld 563 rep 564 movsb 565 566#ifdef NFS_ROOT 567#ifndef BOOTP_NFSV3 568 /* 569 * If we have a nfs_diskless structure copy it in 570 */ 571 movl BI_NFS_DISKLESS(%ebx),%esi 572 cmpl $0,%esi 573 je olddiskboot 574 movl $R(nfs_diskless),%edi 575 movl $NFSDISKLESS_SIZE,%ecx 576 cld 577 rep 578 movsb 579 movl $R(nfs_diskless_valid),%edi 580 movl $1,(%edi) 581#endif 582#endif 583 584 /* 585 * The old style disk boot. 586 * (*btext)(howto, bootdev, cyloffset, esym); 587 * Note that the newer boot code just falls into here to pick 588 * up howto and bootdev, cyloffset and esym are no longer used 589 */ 590olddiskboot: 591 movl 8(%ebp),%eax 592 movl %eax,R(boothowto) 593 movl 12(%ebp),%eax 594 movl %eax,R(bootdev) 595 596 ret 597 598 599/********************************************************************** 600 * 601 * Identify the CPU and initialize anything special about it 602 * 603 */ 604identify_cpu: 605 606 /* Try to toggle alignment check flag; does not exist on 386. */ 607 pushfl 608 popl %eax 609 movl %eax,%ecx 610 orl $PSL_AC,%eax 611 pushl %eax 612 popfl 613 pushfl 614 popl %eax 615 xorl %ecx,%eax 616 andl $PSL_AC,%eax 617 pushl %ecx 618 popfl 619 620 testl %eax,%eax 621 jnz try486 622 623 /* NexGen CPU does not have aligment check flag. */ 624 pushfl 625 movl $0x5555, %eax 626 xorl %edx, %edx 627 movl $2, %ecx 628 clc 629 divl %ecx 630 jz trynexgen 631 popfl 632 movl $CPU_386,R(cpu) 633 jmp 3f 634 635trynexgen: 636 popfl 637 movl $CPU_NX586,R(cpu) 638 movl $0x4778654e,R(cpu_vendor) # store vendor string 639 movl $0x72446e65,R(cpu_vendor+4) 640 movl $0x6e657669,R(cpu_vendor+8) 641 movl $0,R(cpu_vendor+12) 642 jmp 3f 643 644try486: /* Try to toggle identification flag; does not exist on early 486s. */ 645 pushfl 646 popl %eax 647 movl %eax,%ecx 648 xorl $PSL_ID,%eax 649 pushl %eax 650 popfl 651 pushfl 652 popl %eax 653 xorl %ecx,%eax 654 andl $PSL_ID,%eax 655 pushl %ecx 656 popfl 657 658 testl %eax,%eax 659 jnz trycpuid 660 movl $CPU_486,R(cpu) 661 662 /* 663 * Check Cyrix CPU 664 * Cyrix CPUs do not change the undefined flags following 665 * execution of the divide instruction which divides 5 by 2. 666 * 667 * Note: CPUID is enabled on M2, so it passes another way. 668 */ 669 pushfl 670 movl $0x5555, %eax 671 xorl %edx, %edx 672 movl $2, %ecx 673 clc 674 divl %ecx 675 jnc trycyrix 676 popfl 677 jmp 3f /* You may use Intel CPU. */ 678 679trycyrix: 680 popfl 681 /* 682 * IBM Bluelighting CPU also doesn't change the undefined flags. 683 * Because IBM doesn't disclose the information for Bluelighting 684 * CPU, we couldn't distinguish it from Cyrix's (including IBM 685 * brand of Cyrix CPUs). 686 */ 687 movl $0x69727943,R(cpu_vendor) # store vendor string 688 movl $0x736e4978,R(cpu_vendor+4) 689 movl $0x64616574,R(cpu_vendor+8) 690 jmp 3f 691 692trycpuid: /* Use the `cpuid' instruction. */ 693 xorl %eax,%eax 694 cpuid # cpuid 0 695 movl %eax,R(cpu_high) # highest capability 696 movl %ebx,R(cpu_vendor) # store vendor string 697 movl %edx,R(cpu_vendor+4) 698 movl %ecx,R(cpu_vendor+8) 699 movb $0,R(cpu_vendor+12) 700 701 movl $1,%eax 702 cpuid # cpuid 1 703 movl %eax,R(cpu_id) # store cpu_id 704 movl %edx,R(cpu_feature) # store cpu_feature 705 rorl $8,%eax # extract family type 706 andl $15,%eax 707 cmpl $5,%eax 708 jae 1f 709 710 /* less than Pentium; must be 486 */ 711 movl $CPU_486,R(cpu) 712 jmp 3f 7131: 714 /* a Pentium? */ 715 cmpl $5,%eax 716 jne 2f 717 movl $CPU_586,R(cpu) 718 jmp 3f 7192: 720 /* Greater than Pentium...call it a Pentium Pro */ 721 movl $CPU_686,R(cpu) 7223: 723 ret 724 725 726/********************************************************************** 727 * 728 * Create the first page directory and its page tables. 729 * 730 */ 731 732create_pagetables: 733 734/* Find end of kernel image (rounded up to a page boundary). */ 735 movl $R(_end),%esi 736 737/* Include symbols, if any. */ 738 movl R(bootinfo+BI_ESYMTAB),%edi 739 testl %edi,%edi 740 je over_symalloc 741 movl %edi,%esi 742 movl $KERNBASE,%edi 743 addl %edi,R(bootinfo+BI_SYMTAB) 744 addl %edi,R(bootinfo+BI_ESYMTAB) 745over_symalloc: 746 747/* If we are told where the end of the kernel space is, believe it. */ 748 movl R(bootinfo+BI_KERNEND),%edi 749 testl %edi,%edi 750 je no_kernend 751 movl %edi,%esi 752no_kernend: 753 754 addl $PAGE_MASK,%esi 755 andl $~PAGE_MASK,%esi 756 movl %esi,R(KERNend) /* save end of kernel */ 757 movl %esi,R(physfree) /* next free page is at end of kernel */ 758 759/* Allocate Kernel Page Tables */ 760 ALLOCPAGES(NKPT) 761 movl %esi,R(KPTphys) 762 763/* Allocate Page Table Directory */ 764 ALLOCPAGES(1) 765 movl %esi,R(IdlePTD) 766 767/* Allocate UPAGES */ 768 ALLOCPAGES(UAREA_PAGES) 769 movl %esi,R(p0upa) 770 addl $KERNBASE, %esi 771 movl %esi, R(proc0uarea) 772 773 ALLOCPAGES(KSTACK_PAGES) 774 movl %esi,R(p0kpa) 775 addl $KERNBASE, %esi 776 movl %esi, R(proc0kstack) 777 778 ALLOCPAGES(1) /* vm86/bios stack */ 779 movl %esi,R(vm86phystk) 780 781 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 782 movl %esi,R(vm86pa) 783 addl $KERNBASE, %esi 784 movl %esi, R(vm86paddr) 785 786#ifdef SMP 787/* Allocate cpu0's private data page */ 788 ALLOCPAGES(1) 789 movl %esi,R(cpu0pp) 790 addl $KERNBASE, %esi 791 movl %esi, R(cpu0prvpage) /* relocated to KVM space */ 792 793/* Allocate SMP page table page */ 794 ALLOCPAGES(1) 795 movl %esi,R(SMPptpa) 796 addl $KERNBASE, %esi 797 movl %esi, R(SMPpt) /* relocated to KVM space */ 798#endif /* SMP */ 799 800/* Map read-only from zero to the end of the kernel text section */ 801 xorl %eax, %eax 802#ifdef BDE_DEBUGGER 803/* If the debugger is present, actually map everything read-write. */ 804 cmpl $0,R(_bdb_exists) 805 jne map_read_write 806#endif 807 xorl %edx,%edx 808 809#if !defined(SMP) 810 testl $CPUID_PGE, R(cpu_feature) 811 jz 2f 812 orl $PG_G,%edx 813#endif 814 8152: movl $R(etext),%ecx 816 addl $PAGE_MASK,%ecx 817 shrl $PAGE_SHIFT,%ecx 818 fillkptphys(%edx) 819 820/* Map read-write, data, bss and symbols */ 821 movl $R(etext),%eax 822 addl $PAGE_MASK, %eax 823 andl $~PAGE_MASK, %eax 824map_read_write: 825 movl $PG_RW,%edx 826#if !defined(SMP) 827 testl $CPUID_PGE, R(cpu_feature) 828 jz 1f 829 orl $PG_G,%edx 830#endif 831 8321: movl R(KERNend),%ecx 833 subl %eax,%ecx 834 shrl $PAGE_SHIFT,%ecx 835 fillkptphys(%edx) 836 837/* Map page directory. */ 838 movl R(IdlePTD), %eax 839 movl $1, %ecx 840 fillkptphys($PG_RW) 841 842/* Map proc0's UPAGES in the physical way ... */ 843 movl R(p0upa), %eax 844 movl $(UAREA_PAGES), %ecx 845 fillkptphys($PG_RW) 846 847/* Map proc0's KSTACK in the physical way ... */ 848 movl R(p0kpa), %eax 849 movl $(KSTACK_PAGES), %ecx 850 fillkptphys($PG_RW) 851 852/* Map ISA hole */ 853 movl $ISA_HOLE_START, %eax 854 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 855 fillkptphys($PG_RW) 856 857/* Map space for the vm86 region */ 858 movl R(vm86phystk), %eax 859 movl $4, %ecx 860 fillkptphys($PG_RW) 861 862/* Map page 0 into the vm86 page table */ 863 movl $0, %eax 864 movl $0, %ebx 865 movl $1, %ecx 866 fillkpt(R(vm86pa), $PG_RW|PG_U) 867 868/* ...likewise for the ISA hole */ 869 movl $ISA_HOLE_START, %eax 870 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 871 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 872 fillkpt(R(vm86pa), $PG_RW|PG_U) 873 874#ifdef SMP 875/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 876 movl R(cpu0pp), %eax 877 movl $1, %ecx 878 fillkptphys($PG_RW) 879 880/* Map SMP page table page into global kmem FWIW */ 881 movl R(SMPptpa), %eax 882 movl $1, %ecx 883 fillkptphys($PG_RW) 884 885/* Map the private page into the SMP page table */ 886 movl R(cpu0pp), %eax 887 movl $0, %ebx /* pte offset = 0 */ 888 movl $1, %ecx /* one private page coming right up */ 889 fillkpt(R(SMPptpa), $PG_RW) 890 891/* ... and put the page table table in the pde. */ 892 movl R(SMPptpa), %eax 893 movl $MPPTDI, %ebx 894 movl $1, %ecx 895 fillkpt(R(IdlePTD), $PG_RW) 896 897/* Fakeup VA for the local apic to allow early traps. */ 898 ALLOCPAGES(1) 899 movl %esi, %eax 900 movl $(NPTEPG-1), %ebx /* pte offset = NTEPG-1 */ 901 movl $1, %ecx /* one private pt coming right up */ 902 fillkpt(R(SMPptpa), $PG_RW) 903#endif /* SMP */ 904 905/* install a pde for temporary double map of bottom of VA */ 906 movl R(KPTphys), %eax 907 xorl %ebx, %ebx 908 movl $NKPT, %ecx 909 fillkpt(R(IdlePTD), $PG_RW) 910 911/* install pde's for pt's */ 912 movl R(KPTphys), %eax 913 movl $KPTDI, %ebx 914 movl $NKPT, %ecx 915 fillkpt(R(IdlePTD), $PG_RW) 916 917/* install a pde recursively mapping page directory as a page table */ 918 movl R(IdlePTD), %eax 919 movl $PTDPTDI, %ebx 920 movl $1,%ecx 921 fillkpt(R(IdlePTD), $PG_RW) 922 923 ret 924 925#ifdef BDE_DEBUGGER 926bdb_prepare_paging: 927 cmpl $0,R(_bdb_exists) 928 je bdb_prepare_paging_exit 929 930 subl $6,%esp 931 932 /* 933 * Copy and convert debugger entries from the bootstrap gdt and idt 934 * to the kernel gdt and idt. Everything is still in low memory. 935 * Tracing continues to work after paging is enabled because the 936 * low memory addresses remain valid until everything is relocated. 937 * However, tracing through the setidt() that initializes the trace 938 * trap will crash. 939 */ 940 sgdt (%esp) 941 movl 2(%esp),%esi /* base address of bootstrap gdt */ 942 movl $R(_gdt),%edi 943 movl %edi,2(%esp) /* prepare to load kernel gdt */ 944 movl $8*18/4,%ecx 945 cld 946 rep /* copy gdt */ 947 movsl 948 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 949 movb $0x92,-8+5(%edi) 950 lgdt (%esp) 951 952 sidt (%esp) 953 movl 2(%esp),%esi /* base address of current idt */ 954 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 955 movw 8(%esi),%ax 956 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 957 movl 8+2(%esi),%eax 958 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 959 movl 24+4(%esi),%eax /* same for bpt descriptor */ 960 movw 24(%esi),%ax 961 movl %eax,R(bdb_bpt_ljmp+1) 962 movl 24+2(%esi),%eax 963 movw %ax,R(bdb_bpt_ljmp+5) 964 movl R(_idt),%edi 965 movl %edi,2(%esp) /* prepare to load kernel idt */ 966 movl $8*4/4,%ecx 967 cld 968 rep /* copy idt */ 969 movsl 970 lidt (%esp) 971 972 addl $6,%esp 973 974bdb_prepare_paging_exit: 975 ret 976 977/* Relocate debugger gdt entries and gdt and idt pointers. */ 978bdb_commit_paging: 979 cmpl $0,_bdb_exists 980 je bdb_commit_paging_exit 981 982 movl $gdt+8*9,%eax /* adjust slots 9-17 */ 983 movl $9,%ecx 984reloc_gdt: 985 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 986 addl $8,%eax /* now KERNBASE>>24 */ 987 loop reloc_gdt 988 989 subl $6,%esp 990 sgdt (%esp) 991 addl $KERNBASE,2(%esp) 992 lgdt (%esp) 993 sidt (%esp) 994 addl $KERNBASE,2(%esp) 995 lidt (%esp) 996 addl $6,%esp 997 998 int $3 999 1000bdb_commit_paging_exit: 1001 ret 1002 1003#endif /* BDE_DEBUGGER */ 1004