locore.s revision 91367
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 91367 2002-02-27 09:51:33Z 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_compat.h" 48#include "opt_nfsroot.h" 49 50#include <sys/syscall.h> 51#include <sys/reboot.h> 52 53#include <machine/asmacros.h> 54#include <machine/cputypes.h> 55#include <machine/psl.h> 56#include <machine/pmap.h> 57#include <machine/specialreg.h> 58 59#include "assym.s" 60 61#ifdef __AOUT__ 62#define etext _etext 63#define edata _edata 64#define end _end 65#endif 66 67/* 68 * XXX 69 * 70 * Note: This version greatly munged to avoid various assembler errors 71 * that may be fixed in newer versions of gas. Perhaps newer versions 72 * will have more pleasant appearance. 73 */ 74 75/* 76 * PTmap is recursive pagemap at top of virtual address space. 77 * Within PTmap, the page directory can be found (third indirection). 78 * 79 * NOTE: PTDpde, PTmap, and PTD are being defined as address symbols. 80 * In C you access them directly, and not with a '*'. Storage is not being 81 * allocated. They will magically address the correct locations in KVM 82 * which C will treat as normal variables of the type they are defined in 83 * machine/pmap.h, i.e. PTDpde = XX ; to set a PDE entry, NOT *PTDpde = XX; 84 */ 85 .globl PTmap,PTD,PTDpde 86 .set PTmap,(PTDPTDI << PDRSHIFT) 87 .set PTD,PTmap + (PTDPTDI * PAGE_SIZE) 88 .set PTDpde,PTD + (PTDPTDI * PDESIZE) 89 90/* 91 * APTmap, APTD is the alternate recursive pagemap. 92 * It's used when modifying another process's page tables. 93 * See the note above. It is true here as well. 94 */ 95 .globl APTmap,APTD,APTDpde 96 .set APTmap,APTDPTDI << PDRSHIFT 97 .set APTD,APTmap + (APTDPTDI * PAGE_SIZE) 98 .set APTDpde,PTD + (APTDPTDI * PDESIZE) 99 100#ifdef SMP 101/* 102 * Define layout of per-cpu address space. 103 * This is "constructed" in locore.s on the BSP and in mp_machdep.c 104 * for each AP. DO NOT REORDER THESE WITHOUT UPDATING THE REST! 105 */ 106 .globl SMP_prvspace, lapic 107 .set SMP_prvspace,(MPPTDI << PDRSHIFT) 108 .set lapic,SMP_prvspace + (NPTEPG-1) * PAGE_SIZE 109#endif /* SMP */ 110 111/* 112 * Compiled KERNBASE location 113 */ 114 .globl kernbase 115 .set kernbase,KERNBASE 116 117/* 118 * Globals 119 */ 120 .data 121 ALIGN_DATA /* just to be sure */ 122 123 .globl HIDENAME(tmpstk) 124 .space 0x2000 /* space for tmpstk - temporary stack */ 125HIDENAME(tmpstk): 126 127 .globl bootinfo 128bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 129 130KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 131physfree: .long 0 /* phys addr of next free page */ 132 133#ifdef SMP 134 .globl cpu0prvpage 135cpu0pp: .long 0 /* phys addr cpu0 private pg */ 136cpu0prvpage: .long 0 /* relocated version */ 137 138 .globl SMPpt 139SMPptpa: .long 0 /* phys addr SMP page table */ 140SMPpt: .long 0 /* relocated version */ 141#endif /* SMP */ 142 143 .globl IdlePTD 144IdlePTD: .long 0 /* phys addr of kernel PTD */ 145 146#ifdef SMP 147 .globl KPTphys 148#endif 149KPTphys: .long 0 /* phys addr of kernel page tables */ 150 151 .globl proc0uarea, proc0kstack 152proc0uarea: .long 0 /* address of proc 0 uarea space */ 153proc0kstack: .long 0 /* address of proc 0 kstack space */ 154p0upa: .long 0 /* phys addr of proc0's UAREA */ 155p0kpa: .long 0 /* phys addr of proc0's STACK */ 156 157vm86phystk: .long 0 /* PA of vm86/bios stack */ 158 159 .globl vm86paddr, vm86pa 160vm86paddr: .long 0 /* address of vm86 region */ 161vm86pa: .long 0 /* phys addr of vm86 region */ 162 163#ifdef BDE_DEBUGGER 164 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 165_bdb_exists: .long 0 166#endif 167 168#ifdef PC98 169 .globl pc98_system_parameter 170pc98_system_parameter: 171 .space 0x240 172#endif 173 174/********************************************************************** 175 * 176 * Some handy macros 177 * 178 */ 179 180#define R(foo) ((foo)-KERNBASE) 181 182#define ALLOCPAGES(foo) \ 183 movl R(physfree), %esi ; \ 184 movl $((foo)*PAGE_SIZE), %eax ; \ 185 addl %esi, %eax ; \ 186 movl %eax, R(physfree) ; \ 187 movl %esi, %edi ; \ 188 movl $((foo)*PAGE_SIZE),%ecx ; \ 189 xorl %eax,%eax ; \ 190 cld ; \ 191 rep ; \ 192 stosb 193 194/* 195 * fillkpt 196 * eax = page frame address 197 * ebx = index into page table 198 * ecx = how many pages to map 199 * base = base address of page dir/table 200 * prot = protection bits 201 */ 202#define fillkpt(base, prot) \ 203 shll $2,%ebx ; \ 204 addl base,%ebx ; \ 205 orl $PG_V,%eax ; \ 206 orl prot,%eax ; \ 2071: movl %eax,(%ebx) ; \ 208 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 209 addl $4,%ebx ; /* next pte */ \ 210 loop 1b 211 212/* 213 * fillkptphys(prot) 214 * eax = physical address 215 * ecx = how many pages to map 216 * prot = protection bits 217 */ 218#define fillkptphys(prot) \ 219 movl %eax, %ebx ; \ 220 shrl $PAGE_SHIFT, %ebx ; \ 221 fillkpt(R(KPTphys), prot) 222 223 .text 224/********************************************************************** 225 * 226 * This is where the bootblocks start us, set the ball rolling... 227 * 228 */ 229NON_GPROF_ENTRY(btext) 230 231#ifdef PC98 232 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 233 movl $0xa1400,%esi 234 movl $R(pc98_system_parameter),%edi 235 movl $0x0240,%ecx 236 cld 237 rep 238 movsb 239#else /* IBM-PC */ 240#ifdef BDE_DEBUGGER 241#ifdef BIOS_STEALS_3K 242 cmpl $0x0375c339,0x95504 243#else 244 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 245#endif 246 jne 1f 247 movb $1,R(_bdb_exists) 2481: 249#endif 250/* Tell the bios to warmboot next time */ 251 movw $0x1234,0x472 252#endif /* PC98 */ 253 254/* Set up a real frame in case the double return in newboot is executed. */ 255 pushl %ebp 256 movl %esp, %ebp 257 258/* Don't trust what the BIOS gives for eflags. */ 259 pushl $PSL_KERNEL 260 popfl 261 262/* 263 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 264 * to set %cs, %ds, %es and %ss. 265 */ 266 mov %ds, %ax 267 mov %ax, %fs 268 mov %ax, %gs 269 270 call recover_bootinfo 271 272/* Get onto a stack that we can trust. */ 273/* 274 * XXX this step is delayed in case recover_bootinfo needs to return via 275 * the old stack, but it need not be, since recover_bootinfo actually 276 * returns via the old frame. 277 */ 278 movl $R(HIDENAME(tmpstk)),%esp 279 280#ifdef PC98 281 /* pc98_machine_type & M_EPSON_PC98 */ 282 testb $0x02,R(pc98_system_parameter)+220 283 jz 3f 284 /* epson_machine_id <= 0x0b */ 285 cmpb $0x0b,R(pc98_system_parameter)+224 286 ja 3f 287 288 /* count up memory */ 289 movl $0x100000,%eax /* next, talley remaining memory */ 290 movl $0xFFF-0x100,%ecx 2911: movl 0(%eax),%ebx /* save location to check */ 292 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 293 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 294 jne 2f 295 movl %ebx,0(%eax) /* restore memory */ 296 addl $PAGE_SIZE,%eax 297 loop 1b 2982: subl $0x100000,%eax 299 shrl $17,%eax 300 movb %al,R(pc98_system_parameter)+1 3013: 302 303 movw R(pc98_system_parameter+0x86),%ax 304 movw %ax,R(cpu_id) 305#endif 306 307 call identify_cpu 308 309/* clear bss */ 310/* 311 * XXX this should be done a little earlier. 312 * 313 * XXX we don't check that there is memory for our bss and page tables 314 * before using it. 315 * 316 * XXX the boot program somewhat bogusly clears the bss. We still have 317 * to do it in case we were unzipped by kzipboot. Then the boot program 318 * only clears kzipboot's bss. 319 * 320 * XXX the gdt and idt are still somewhere in the boot program. We 321 * depend on the convention that the boot program is below 1MB and we 322 * are above 1MB to keep the gdt and idt away from the bss and page 323 * tables. The idt is only used if BDE_DEBUGGER is enabled. 324 */ 325 movl $R(end),%ecx 326 movl $R(edata),%edi 327 subl %edi,%ecx 328 xorl %eax,%eax 329 cld 330 rep 331 stosb 332 333 call create_pagetables 334 335/* 336 * If the CPU has support for VME, turn it on. 337 */ 338 testl $CPUID_VME, R(cpu_feature) 339 jz 1f 340 movl %cr4, %eax 341 orl $CR4_VME, %eax 342 movl %eax, %cr4 3431: 344 345#ifdef BDE_DEBUGGER 346/* 347 * Adjust as much as possible for paging before enabling paging so that the 348 * adjustments can be traced. 349 */ 350 call bdb_prepare_paging 351#endif 352 353/* Now enable paging */ 354 movl R(IdlePTD), %eax 355 movl %eax,%cr3 /* load ptd addr into mmu */ 356 movl %cr0,%eax /* get control word */ 357 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 358 movl %eax,%cr0 /* and let's page NOW! */ 359 360#ifdef BDE_DEBUGGER 361/* 362 * Complete the adjustments for paging so that we can keep tracing through 363 * initi386() after the low (physical) addresses for the gdt and idt become 364 * invalid. 365 */ 366 call bdb_commit_paging 367#endif 368 369 pushl $begin /* jump to high virtualized address */ 370 ret 371 372/* now running relocated at KERNBASE where the system is linked to run */ 373begin: 374 /* set up bootstrap stack */ 375 movl proc0kstack,%eax /* location of in-kernel stack */ 376 /* bootstrap stack end location */ 377 leal (KSTACK_PAGES*PAGE_SIZE-PCB_SIZE)(%eax),%esp 378 379 xorl %ebp,%ebp /* mark end of frames */ 380 381 movl IdlePTD,%esi 382 movl %esi,(KSTACK_PAGES*PAGE_SIZE-PCB_SIZE+PCB_CR3)(%eax) 383 384 testl $CPUID_PGE, R(cpu_feature) 385 jz 1f 386 movl %cr4, %eax 387 orl $CR4_PGE, %eax 388 movl %eax, %cr4 3891: 390 pushl physfree /* value of first for init386(first) */ 391 call init386 /* wire 386 chip for unix operation */ 392 393 /* 394 * Clean up the stack in a way that db_numargs() understands, so 395 * that backtraces in ddb don't underrun the stack. Traps for 396 * inaccessible memory are more fatal than usual this early. 397 */ 398 addl $4,%esp 399 400 call mi_startup /* autoconfiguration, mountroot etc */ 401 /* NOTREACHED */ 402 addl $0,%esp /* for db_numargs() again */ 403 404/* 405 * Signal trampoline, copied to top of user stack 406 */ 407NON_GPROF_ENTRY(sigcode) 408 call *SIGF_HANDLER(%esp) /* call signal handler */ 409 lea SIGF_UC(%esp),%eax /* get ucontext_t */ 410 pushl %eax 411 testl $PSL_VM,UC_EFLAGS(%eax) 412 jne 9f 413 movl UC_GS(%eax),%gs /* restore %gs */ 4149: 415 movl $SYS_sigreturn,%eax 416 pushl %eax /* junk to fake return addr. */ 417 int $0x80 /* enter kernel with args */ 4180: jmp 0b 419 420#ifdef COMPAT_43 421 ALIGN_TEXT 422osigcode: 423 call *SIGF_HANDLER(%esp) /* call signal handler */ 424 lea SIGF_SC(%esp),%eax /* get sigcontext */ 425 pushl %eax 426 testl $PSL_VM,SC_PS(%eax) 427 jne 9f 428 movl SC_GS(%eax),%gs /* restore %gs */ 4299: 430 movl $SYS_osigreturn,%eax 431 pushl %eax /* junk to fake return addr. */ 432 int $0x80 /* enter kernel with args */ 4330: jmp 0b 434#endif /* COMPAT_43 */ 435 436 ALIGN_TEXT 437esigcode: 438 439 .data 440 .globl szsigcode, szosigcode 441szsigcode: 442 .long esigcode-sigcode 443#ifdef COMPAT_43 444szosigcode: 445 .long esigcode-osigcode 446#endif 447 .text 448 449/********************************************************************** 450 * 451 * Recover the bootinfo passed to us from the boot program 452 * 453 */ 454recover_bootinfo: 455 /* 456 * This code is called in different ways depending on what loaded 457 * and started the kernel. This is used to detect how we get the 458 * arguments from the other code and what we do with them. 459 * 460 * Old disk boot blocks: 461 * (*btext)(howto, bootdev, cyloffset, esym); 462 * [return address == 0, and can NOT be returned to] 463 * [cyloffset was not supported by the FreeBSD boot code 464 * and always passed in as 0] 465 * [esym is also known as total in the boot code, and 466 * was never properly supported by the FreeBSD boot code] 467 * 468 * Old diskless netboot code: 469 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 470 * [return address != 0, and can NOT be returned to] 471 * If we are being booted by this code it will NOT work, 472 * so we are just going to halt if we find this case. 473 * 474 * New uniform boot code: 475 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 476 * [return address != 0, and can be returned to] 477 * 478 * There may seem to be a lot of wasted arguments in here, but 479 * that is so the newer boot code can still load very old kernels 480 * and old boot code can load new kernels. 481 */ 482 483 /* 484 * The old style disk boot blocks fake a frame on the stack and 485 * did an lret to get here. The frame on the stack has a return 486 * address of 0. 487 */ 488 cmpl $0,4(%ebp) 489 je olddiskboot 490 491 /* 492 * We have some form of return address, so this is either the 493 * old diskless netboot code, or the new uniform code. That can 494 * be detected by looking at the 5th argument, if it is 0 495 * we are being booted by the new uniform boot code. 496 */ 497 cmpl $0,24(%ebp) 498 je newboot 499 500 /* 501 * Seems we have been loaded by the old diskless boot code, we 502 * don't stand a chance of running as the diskless structure 503 * changed considerably between the two, so just halt. 504 */ 505 hlt 506 507 /* 508 * We have been loaded by the new uniform boot code. 509 * Let's check the bootinfo version, and if we do not understand 510 * it we return to the loader with a status of 1 to indicate this error 511 */ 512newboot: 513 movl 28(%ebp),%ebx /* &bootinfo.version */ 514 movl BI_VERSION(%ebx),%eax 515 cmpl $1,%eax /* We only understand version 1 */ 516 je 1f 517 movl $1,%eax /* Return status */ 518 leave 519 /* 520 * XXX this returns to our caller's caller (as is required) since 521 * we didn't set up a frame and our caller did. 522 */ 523 ret 524 5251: 526 /* 527 * If we have a kernelname copy it in 528 */ 529 movl BI_KERNELNAME(%ebx),%esi 530 cmpl $0,%esi 531 je 2f /* No kernelname */ 532 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 533 movl $R(kernelname),%edi 534 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 535 je 1f 536 movb $'/',(%edi) 537 incl %edi 538 decl %ecx 5391: 540 cld 541 rep 542 movsb 543 5442: 545 /* 546 * Determine the size of the boot loader's copy of the bootinfo 547 * struct. This is impossible to do properly because old versions 548 * of the struct don't contain a size field and there are 2 old 549 * versions with the same version number. 550 */ 551 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 552 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 553 je got_bi_size /* no, sizeless version */ 554 movl BI_SIZE(%ebx),%ecx 555got_bi_size: 556 557 /* 558 * Copy the common part of the bootinfo struct 559 */ 560 movl %ebx,%esi 561 movl $R(bootinfo),%edi 562 cmpl $BOOTINFO_SIZE,%ecx 563 jbe got_common_bi_size 564 movl $BOOTINFO_SIZE,%ecx 565got_common_bi_size: 566 cld 567 rep 568 movsb 569 570#ifdef NFS_ROOT 571#ifndef BOOTP_NFSV3 572 /* 573 * If we have a nfs_diskless structure copy it in 574 */ 575 movl BI_NFS_DISKLESS(%ebx),%esi 576 cmpl $0,%esi 577 je olddiskboot 578 movl $R(nfs_diskless),%edi 579 movl $NFSDISKLESS_SIZE,%ecx 580 cld 581 rep 582 movsb 583 movl $R(nfs_diskless_valid),%edi 584 movl $1,(%edi) 585#endif 586#endif 587 588 /* 589 * The old style disk boot. 590 * (*btext)(howto, bootdev, cyloffset, esym); 591 * Note that the newer boot code just falls into here to pick 592 * up howto and bootdev, cyloffset and esym are no longer used 593 */ 594olddiskboot: 595 movl 8(%ebp),%eax 596 movl %eax,R(boothowto) 597 movl 12(%ebp),%eax 598 movl %eax,R(bootdev) 599 600 ret 601 602 603/********************************************************************** 604 * 605 * Identify the CPU and initialize anything special about it 606 * 607 */ 608identify_cpu: 609 610 /* Try to toggle alignment check flag; does not exist on 386. */ 611 pushfl 612 popl %eax 613 movl %eax,%ecx 614 orl $PSL_AC,%eax 615 pushl %eax 616 popfl 617 pushfl 618 popl %eax 619 xorl %ecx,%eax 620 andl $PSL_AC,%eax 621 pushl %ecx 622 popfl 623 624 testl %eax,%eax 625 jnz try486 626 627 /* NexGen CPU does not have aligment check flag. */ 628 pushfl 629 movl $0x5555, %eax 630 xorl %edx, %edx 631 movl $2, %ecx 632 clc 633 divl %ecx 634 jz trynexgen 635 popfl 636 movl $CPU_386,R(cpu) 637 jmp 3f 638 639trynexgen: 640 popfl 641 movl $CPU_NX586,R(cpu) 642 movl $0x4778654e,R(cpu_vendor) # store vendor string 643 movl $0x72446e65,R(cpu_vendor+4) 644 movl $0x6e657669,R(cpu_vendor+8) 645 movl $0,R(cpu_vendor+12) 646 jmp 3f 647 648try486: /* Try to toggle identification flag; does not exist on early 486s. */ 649 pushfl 650 popl %eax 651 movl %eax,%ecx 652 xorl $PSL_ID,%eax 653 pushl %eax 654 popfl 655 pushfl 656 popl %eax 657 xorl %ecx,%eax 658 andl $PSL_ID,%eax 659 pushl %ecx 660 popfl 661 662 testl %eax,%eax 663 jnz trycpuid 664 movl $CPU_486,R(cpu) 665 666 /* 667 * Check Cyrix CPU 668 * Cyrix CPUs do not change the undefined flags following 669 * execution of the divide instruction which divides 5 by 2. 670 * 671 * Note: CPUID is enabled on M2, so it passes another way. 672 */ 673 pushfl 674 movl $0x5555, %eax 675 xorl %edx, %edx 676 movl $2, %ecx 677 clc 678 divl %ecx 679 jnc trycyrix 680 popfl 681 jmp 3f /* You may use Intel CPU. */ 682 683trycyrix: 684 popfl 685 /* 686 * IBM Bluelighting CPU also doesn't change the undefined flags. 687 * Because IBM doesn't disclose the information for Bluelighting 688 * CPU, we couldn't distinguish it from Cyrix's (including IBM 689 * brand of Cyrix CPUs). 690 */ 691 movl $0x69727943,R(cpu_vendor) # store vendor string 692 movl $0x736e4978,R(cpu_vendor+4) 693 movl $0x64616574,R(cpu_vendor+8) 694 jmp 3f 695 696trycpuid: /* Use the `cpuid' instruction. */ 697 xorl %eax,%eax 698 cpuid # cpuid 0 699 movl %eax,R(cpu_high) # highest capability 700 movl %ebx,R(cpu_vendor) # store vendor string 701 movl %edx,R(cpu_vendor+4) 702 movl %ecx,R(cpu_vendor+8) 703 movb $0,R(cpu_vendor+12) 704 705 movl $1,%eax 706 cpuid # cpuid 1 707 movl %eax,R(cpu_id) # store cpu_id 708 movl %edx,R(cpu_feature) # store cpu_feature 709 rorl $8,%eax # extract family type 710 andl $15,%eax 711 cmpl $5,%eax 712 jae 1f 713 714 /* less than Pentium; must be 486 */ 715 movl $CPU_486,R(cpu) 716 jmp 3f 7171: 718 /* a Pentium? */ 719 cmpl $5,%eax 720 jne 2f 721 movl $CPU_586,R(cpu) 722 jmp 3f 7232: 724 /* Greater than Pentium...call it a Pentium Pro */ 725 movl $CPU_686,R(cpu) 7263: 727 ret 728 729 730/********************************************************************** 731 * 732 * Create the first page directory and its page tables. 733 * 734 */ 735 736create_pagetables: 737 738/* Find end of kernel image (rounded up to a page boundary). */ 739 movl $R(_end),%esi 740 741/* Include symbols, if any. */ 742 movl R(bootinfo+BI_ESYMTAB),%edi 743 testl %edi,%edi 744 je over_symalloc 745 movl %edi,%esi 746 movl $KERNBASE,%edi 747 addl %edi,R(bootinfo+BI_SYMTAB) 748 addl %edi,R(bootinfo+BI_ESYMTAB) 749over_symalloc: 750 751/* If we are told where the end of the kernel space is, believe it. */ 752 movl R(bootinfo+BI_KERNEND),%edi 753 testl %edi,%edi 754 je no_kernend 755 movl %edi,%esi 756no_kernend: 757 758 addl $PAGE_MASK,%esi 759 andl $~PAGE_MASK,%esi 760 movl %esi,R(KERNend) /* save end of kernel */ 761 movl %esi,R(physfree) /* next free page is at end of kernel */ 762 763/* Allocate Kernel Page Tables */ 764 ALLOCPAGES(NKPT) 765 movl %esi,R(KPTphys) 766 767/* Allocate Page Table Directory */ 768 ALLOCPAGES(1) 769 movl %esi,R(IdlePTD) 770 771/* Allocate UPAGES */ 772 ALLOCPAGES(UAREA_PAGES) 773 movl %esi,R(p0upa) 774 addl $KERNBASE, %esi 775 movl %esi, R(proc0uarea) 776 777 ALLOCPAGES(KSTACK_PAGES) 778 movl %esi,R(p0kpa) 779 addl $KERNBASE, %esi 780 movl %esi, R(proc0kstack) 781 782 ALLOCPAGES(1) /* vm86/bios stack */ 783 movl %esi,R(vm86phystk) 784 785 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 786 movl %esi,R(vm86pa) 787 addl $KERNBASE, %esi 788 movl %esi, R(vm86paddr) 789 790#ifdef SMP 791/* Allocate cpu0's private data page */ 792 ALLOCPAGES(1) 793 movl %esi,R(cpu0pp) 794 addl $KERNBASE, %esi 795 movl %esi, R(cpu0prvpage) /* relocated to KVM space */ 796 797/* Allocate SMP page table page */ 798 ALLOCPAGES(1) 799 movl %esi,R(SMPptpa) 800 addl $KERNBASE, %esi 801 movl %esi, R(SMPpt) /* relocated to KVM space */ 802#endif /* SMP */ 803 804/* Map read-only from zero to the end of the kernel text section */ 805 xorl %eax, %eax 806#ifdef BDE_DEBUGGER 807/* If the debugger is present, actually map everything read-write. */ 808 cmpl $0,R(_bdb_exists) 809 jne map_read_write 810#endif 811 xorl %edx,%edx 812 813#if !defined(SMP) 814 testl $CPUID_PGE, R(cpu_feature) 815 jz 2f 816 orl $PG_G,%edx 817#endif 818 8192: movl $R(etext),%ecx 820 addl $PAGE_MASK,%ecx 821 shrl $PAGE_SHIFT,%ecx 822 fillkptphys(%edx) 823 824/* Map read-write, data, bss and symbols */ 825 movl $R(etext),%eax 826 addl $PAGE_MASK, %eax 827 andl $~PAGE_MASK, %eax 828map_read_write: 829 movl $PG_RW,%edx 830#if !defined(SMP) 831 testl $CPUID_PGE, R(cpu_feature) 832 jz 1f 833 orl $PG_G,%edx 834#endif 835 8361: movl R(KERNend),%ecx 837 subl %eax,%ecx 838 shrl $PAGE_SHIFT,%ecx 839 fillkptphys(%edx) 840 841/* Map page directory. */ 842 movl R(IdlePTD), %eax 843 movl $1, %ecx 844 fillkptphys($PG_RW) 845 846/* Map proc0's UPAGES in the physical way ... */ 847 movl R(p0upa), %eax 848 movl $(UAREA_PAGES), %ecx 849 fillkptphys($PG_RW) 850 851/* Map proc0's KSTACK in the physical way ... */ 852 movl R(p0kpa), %eax 853 movl $(KSTACK_PAGES), %ecx 854 fillkptphys($PG_RW) 855 856/* Map ISA hole */ 857 movl $ISA_HOLE_START, %eax 858 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 859 fillkptphys($PG_RW) 860 861/* Map space for the vm86 region */ 862 movl R(vm86phystk), %eax 863 movl $4, %ecx 864 fillkptphys($PG_RW) 865 866/* Map page 0 into the vm86 page table */ 867 movl $0, %eax 868 movl $0, %ebx 869 movl $1, %ecx 870 fillkpt(R(vm86pa), $PG_RW|PG_U) 871 872/* ...likewise for the ISA hole */ 873 movl $ISA_HOLE_START, %eax 874 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 875 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 876 fillkpt(R(vm86pa), $PG_RW|PG_U) 877 878#ifdef SMP 879/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 880 movl R(cpu0pp), %eax 881 movl $1, %ecx 882 fillkptphys($PG_RW) 883 884/* Map SMP page table page into global kmem FWIW */ 885 movl R(SMPptpa), %eax 886 movl $1, %ecx 887 fillkptphys($PG_RW) 888 889/* Map the private page into the SMP page table */ 890 movl R(cpu0pp), %eax 891 movl $0, %ebx /* pte offset = 0 */ 892 movl $1, %ecx /* one private page coming right up */ 893 fillkpt(R(SMPptpa), $PG_RW) 894 895/* ... and put the page table table in the pde. */ 896 movl R(SMPptpa), %eax 897 movl $MPPTDI, %ebx 898 movl $1, %ecx 899 fillkpt(R(IdlePTD), $PG_RW) 900 901/* Fakeup VA for the local apic to allow early traps. */ 902 ALLOCPAGES(1) 903 movl %esi, %eax 904 movl $(NPTEPG-1), %ebx /* pte offset = NTEPG-1 */ 905 movl $1, %ecx /* one private pt coming right up */ 906 fillkpt(R(SMPptpa), $PG_RW) 907#endif /* SMP */ 908 909/* install a pde for temporary double map of bottom of VA */ 910 movl R(KPTphys), %eax 911 xorl %ebx, %ebx 912 movl $NKPT, %ecx 913 fillkpt(R(IdlePTD), $PG_RW) 914 915/* install pde's for pt's */ 916 movl R(KPTphys), %eax 917 movl $KPTDI, %ebx 918 movl $NKPT, %ecx 919 fillkpt(R(IdlePTD), $PG_RW) 920 921/* install a pde recursively mapping page directory as a page table */ 922 movl R(IdlePTD), %eax 923 movl $PTDPTDI, %ebx 924 movl $1,%ecx 925 fillkpt(R(IdlePTD), $PG_RW) 926 927 ret 928 929#ifdef BDE_DEBUGGER 930bdb_prepare_paging: 931 cmpl $0,R(_bdb_exists) 932 je bdb_prepare_paging_exit 933 934 subl $6,%esp 935 936 /* 937 * Copy and convert debugger entries from the bootstrap gdt and idt 938 * to the kernel gdt and idt. Everything is still in low memory. 939 * Tracing continues to work after paging is enabled because the 940 * low memory addresses remain valid until everything is relocated. 941 * However, tracing through the setidt() that initializes the trace 942 * trap will crash. 943 */ 944 sgdt (%esp) 945 movl 2(%esp),%esi /* base address of bootstrap gdt */ 946 movl $R(_gdt),%edi 947 movl %edi,2(%esp) /* prepare to load kernel gdt */ 948 movl $8*18/4,%ecx 949 cld 950 rep /* copy gdt */ 951 movsl 952 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 953 movb $0x92,-8+5(%edi) 954 lgdt (%esp) 955 956 sidt (%esp) 957 movl 2(%esp),%esi /* base address of current idt */ 958 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 959 movw 8(%esi),%ax 960 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 961 movl 8+2(%esi),%eax 962 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 963 movl 24+4(%esi),%eax /* same for bpt descriptor */ 964 movw 24(%esi),%ax 965 movl %eax,R(bdb_bpt_ljmp+1) 966 movl 24+2(%esi),%eax 967 movw %ax,R(bdb_bpt_ljmp+5) 968 movl R(_idt),%edi 969 movl %edi,2(%esp) /* prepare to load kernel idt */ 970 movl $8*4/4,%ecx 971 cld 972 rep /* copy idt */ 973 movsl 974 lidt (%esp) 975 976 addl $6,%esp 977 978bdb_prepare_paging_exit: 979 ret 980 981/* Relocate debugger gdt entries and gdt and idt pointers. */ 982bdb_commit_paging: 983 cmpl $0,_bdb_exists 984 je bdb_commit_paging_exit 985 986 movl $gdt+8*9,%eax /* adjust slots 9-17 */ 987 movl $9,%ecx 988reloc_gdt: 989 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 990 addl $8,%eax /* now KERNBASE>>24 */ 991 loop reloc_gdt 992 993 subl $6,%esp 994 sgdt (%esp) 995 addl $KERNBASE,2(%esp) 996 lgdt (%esp) 997 sidt (%esp) 998 addl $KERNBASE,2(%esp) 999 lidt (%esp) 1000 addl $6,%esp 1001 1002 int $3 1003 1004bdb_commit_paging_exit: 1005 ret 1006 1007#endif /* BDE_DEBUGGER */ 1008