locore.s revision 105950
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 105950 2002-10-25 19:10:58Z 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/* 62 * XXX 63 * 64 * Note: This version greatly munged to avoid various assembler errors 65 * that may be fixed in newer versions of gas. Perhaps newer versions 66 * will have more pleasant appearance. 67 */ 68 69/* 70 * PTmap is recursive pagemap at top of virtual address space. 71 * Within PTmap, the page directory can be found (third indirection). 72 * 73 * NOTE: PTDpde, PTmap, and PTD are being defined as address symbols. 74 * In C you access them directly, and not with a '*'. Storage is not being 75 * allocated. They will magically address the correct locations in KVM 76 * which C will treat as normal variables of the type they are defined in 77 * machine/pmap.h, i.e. PTDpde = XX ; to set a PDE entry, NOT *PTDpde = XX; 78 */ 79 .globl PTmap,PTD,PTDpde 80 .set PTmap,(PTDPTDI << PDRSHIFT) 81 .set PTD,PTmap + (PTDPTDI * PAGE_SIZE) 82 .set PTDpde,PTD + (PTDPTDI * PDESIZE) 83 84/* 85 * APTmap, APTD is the alternate recursive pagemap. 86 * It's used when modifying another process's page tables. 87 * See the note above. It is true here as well. 88 */ 89 .globl APTmap,APTD,APTDpde 90 .set APTmap,APTDPTDI << PDRSHIFT 91 .set APTD,APTmap + (APTDPTDI * PAGE_SIZE) 92 .set APTDpde,PTD + (APTDPTDI * PDESIZE) 93 94#ifdef SMP 95/* 96 * Define layout of per-cpu address space. 97 * This is "constructed" in locore.s on the BSP and in mp_machdep.c 98 * for each AP. DO NOT REORDER THESE WITHOUT UPDATING THE REST! 99 */ 100 .globl SMP_prvspace, lapic 101 .set SMP_prvspace,(MPPTDI << PDRSHIFT) 102 .set lapic,SMP_prvspace + (NPTEPG-1) * PAGE_SIZE 103#endif /* SMP */ 104 105/* 106 * Compiled KERNBASE location 107 */ 108 .globl kernbase 109 .set kernbase,KERNBASE 110 111/* 112 * Globals 113 */ 114 .data 115 ALIGN_DATA /* just to be sure */ 116 117 .globl HIDENAME(tmpstk) 118 .space 0x2000 /* space for tmpstk - temporary stack */ 119HIDENAME(tmpstk): 120 121 .globl bootinfo 122bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 123 124 .globl KERNend 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 proc0uarea, proc0kstack 147proc0uarea: .long 0 /* address of proc 0 uarea space */ 148proc0kstack: .long 0 /* address of proc 0 kstack space */ 149p0upa: .long 0 /* phys addr of proc0's UAREA */ 150p0kpa: .long 0 /* phys addr of proc0's STACK */ 151 152vm86phystk: .long 0 /* PA of vm86/bios stack */ 153 154 .globl vm86paddr, vm86pa 155vm86paddr: .long 0 /* address of vm86 region */ 156vm86pa: .long 0 /* phys addr of vm86 region */ 157 158#ifdef BDE_DEBUGGER 159 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 160_bdb_exists: .long 0 161#endif 162 163#ifdef PC98 164 .globl pc98_system_parameter 165pc98_system_parameter: 166 .space 0x240 167#endif 168 169/********************************************************************** 170 * 171 * Some handy macros 172 * 173 */ 174 175#define R(foo) ((foo)-KERNBASE) 176 177#define ALLOCPAGES(foo) \ 178 movl R(physfree), %esi ; \ 179 movl $((foo)*PAGE_SIZE), %eax ; \ 180 addl %esi, %eax ; \ 181 movl %eax, R(physfree) ; \ 182 movl %esi, %edi ; \ 183 movl $((foo)*PAGE_SIZE),%ecx ; \ 184 xorl %eax,%eax ; \ 185 cld ; \ 186 rep ; \ 187 stosb 188 189/* 190 * fillkpt 191 * eax = page frame address 192 * ebx = index into page table 193 * ecx = how many pages to map 194 * base = base address of page dir/table 195 * prot = protection bits 196 */ 197#define fillkpt(base, prot) \ 198 shll $2,%ebx ; \ 199 addl base,%ebx ; \ 200 orl $PG_V,%eax ; \ 201 orl prot,%eax ; \ 2021: movl %eax,(%ebx) ; \ 203 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 204 addl $4,%ebx ; /* next pte */ \ 205 loop 1b 206 207/* 208 * fillkptphys(prot) 209 * eax = physical address 210 * ecx = how many pages to map 211 * prot = protection bits 212 */ 213#define fillkptphys(prot) \ 214 movl %eax, %ebx ; \ 215 shrl $PAGE_SHIFT, %ebx ; \ 216 fillkpt(R(KPTphys), prot) 217 218 .text 219/********************************************************************** 220 * 221 * This is where the bootblocks start us, set the ball rolling... 222 * 223 */ 224NON_GPROF_ENTRY(btext) 225 226#ifdef PC98 227 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 228 movl $0xa1400,%esi 229 movl $R(pc98_system_parameter),%edi 230 movl $0x0240,%ecx 231 cld 232 rep 233 movsb 234#else /* IBM-PC */ 235#ifdef BDE_DEBUGGER 236#ifdef BIOS_STEALS_3K 237 cmpl $0x0375c339,0x95504 238#else 239 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 240#endif 241 jne 1f 242 movb $1,R(_bdb_exists) 2431: 244#endif 245/* Tell the bios to warmboot next time */ 246 movw $0x1234,0x472 247#endif /* PC98 */ 248 249/* Set up a real frame in case the double return in newboot is executed. */ 250 pushl %ebp 251 movl %esp, %ebp 252 253/* Don't trust what the BIOS gives for eflags. */ 254 pushl $PSL_KERNEL 255 popfl 256 257/* 258 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 259 * to set %cs, %ds, %es and %ss. 260 */ 261 mov %ds, %ax 262 mov %ax, %fs 263 mov %ax, %gs 264 265 call recover_bootinfo 266 267/* Get onto a stack that we can trust. */ 268/* 269 * XXX this step is delayed in case recover_bootinfo needs to return via 270 * the old stack, but it need not be, since recover_bootinfo actually 271 * returns via the old frame. 272 */ 273 movl $R(HIDENAME(tmpstk)),%esp 274 275#ifdef PC98 276 /* pc98_machine_type & M_EPSON_PC98 */ 277 testb $0x02,R(pc98_system_parameter)+220 278 jz 3f 279 /* epson_machine_id <= 0x0b */ 280 cmpb $0x0b,R(pc98_system_parameter)+224 281 ja 3f 282 283 /* count up memory */ 284 movl $0x100000,%eax /* next, talley remaining memory */ 285 movl $0xFFF-0x100,%ecx 2861: movl 0(%eax),%ebx /* save location to check */ 287 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 288 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 289 jne 2f 290 movl %ebx,0(%eax) /* restore memory */ 291 addl $PAGE_SIZE,%eax 292 loop 1b 2932: subl $0x100000,%eax 294 shrl $17,%eax 295 movb %al,R(pc98_system_parameter)+1 2963: 297 298 movw R(pc98_system_parameter+0x86),%ax 299 movw %ax,R(cpu_id) 300#endif 301 302 call identify_cpu 303 304/* clear bss */ 305/* 306 * XXX this should be done a little earlier. 307 * 308 * XXX we don't check that there is memory for our bss and page tables 309 * before using it. 310 * 311 * XXX the boot program somewhat bogusly clears the bss. We still have 312 * to do it in case we were unzipped by kzipboot. Then the boot program 313 * only clears kzipboot's bss. 314 * 315 * XXX the gdt and idt are still somewhere in the boot program. We 316 * depend on the convention that the boot program is below 1MB and we 317 * are above 1MB to keep the gdt and idt away from the bss and page 318 * tables. The idt is only used if BDE_DEBUGGER is enabled. 319 */ 320 movl $R(end),%ecx 321 movl $R(edata),%edi 322 subl %edi,%ecx 323 xorl %eax,%eax 324 cld 325 rep 326 stosb 327 328 call create_pagetables 329 330/* 331 * If the CPU has support for VME, turn it on. 332 */ 333 testl $CPUID_VME, R(cpu_feature) 334 jz 1f 335 movl %cr4, %eax 336 orl $CR4_VME, %eax 337 movl %eax, %cr4 3381: 339 340#ifdef BDE_DEBUGGER 341/* 342 * Adjust as much as possible for paging before enabling paging so that the 343 * adjustments can be traced. 344 */ 345 call bdb_prepare_paging 346#endif 347 348/* Now enable paging */ 349 movl R(IdlePTD), %eax 350 movl %eax,%cr3 /* load ptd addr into mmu */ 351 movl %cr0,%eax /* get control word */ 352 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 353 movl %eax,%cr0 /* and let's page NOW! */ 354 355#ifdef BDE_DEBUGGER 356/* 357 * Complete the adjustments for paging so that we can keep tracing through 358 * initi386() after the low (physical) addresses for the gdt and idt become 359 * invalid. 360 */ 361 call bdb_commit_paging 362#endif 363 364 pushl $begin /* jump to high virtualized address */ 365 ret 366 367/* now running relocated at KERNBASE where the system is linked to run */ 368begin: 369 /* set up bootstrap stack */ 370 movl proc0kstack,%eax /* location of in-kernel stack */ 371 /* bootstrap stack end location */ 372 leal (KSTACK_PAGES*PAGE_SIZE-PCB_SIZE)(%eax),%esp 373 374 xorl %ebp,%ebp /* mark end of frames */ 375 376 movl IdlePTD,%esi 377 movl %esi,(KSTACK_PAGES*PAGE_SIZE-PCB_SIZE+PCB_CR3)(%eax) 378 379 pushl physfree /* value of first for init386(first) */ 380 call init386 /* wire 386 chip for unix operation */ 381 382 /* 383 * Clean up the stack in a way that db_numargs() understands, so 384 * that backtraces in ddb don't underrun the stack. Traps for 385 * inaccessible memory are more fatal than usual this early. 386 */ 387 addl $4,%esp 388 389 call mi_startup /* autoconfiguration, mountroot etc */ 390 /* NOTREACHED */ 391 addl $0,%esp /* for db_numargs() again */ 392 393/* 394 * Signal trampoline, copied to top of user stack 395 */ 396NON_GPROF_ENTRY(sigcode) 397 call *SIGF_HANDLER(%esp) /* call signal handler */ 398 lea SIGF_UC(%esp),%eax /* get ucontext_t */ 399 pushl %eax 400 testl $PSL_VM,UC_EFLAGS(%eax) 401 jne 9f 402 movl UC_GS(%eax),%gs /* restore %gs */ 4039: 404 movl $SYS_sigreturn,%eax 405 pushl %eax /* junk to fake return addr. */ 406 int $0x80 /* enter kernel with args */ 4070: jmp 0b 408 409#ifdef COMPAT_FREEBSD4 410 ALIGN_TEXT 411freebsd4_sigcode: 412 call *SIGF_HANDLER(%esp) /* call signal handler */ 413 lea SIGF_UC(%esp),%eax /* get ucontext_t */ 414 pushl %eax 415 testl $PSL_VM,UC4_EFLAGS(%eax) 416 jne 9f 417 movl UC4_GS(%eax),%gs /* restore %gs */ 4189: 419 movl $344,%eax /* 4.x SYS_sigreturn */ 420 pushl %eax /* junk to fake return addr. */ 421 int $0x80 /* enter kernel with args */ 4220: jmp 0b 423#endif 424 425#ifdef COMPAT_43 426 ALIGN_TEXT 427osigcode: 428 call *SIGF_HANDLER(%esp) /* call signal handler */ 429 lea SIGF_SC(%esp),%eax /* get sigcontext */ 430 pushl %eax 431 testl $PSL_VM,SC_PS(%eax) 432 jne 9f 433 movl SC_GS(%eax),%gs /* restore %gs */ 4349: 435 movl $103,%eax /* 3.x SYS_sigreturn */ 436 pushl %eax /* junk to fake return addr. */ 437 int $0x80 /* enter kernel with args */ 4380: jmp 0b 439#endif /* COMPAT_43 */ 440 441 ALIGN_TEXT 442esigcode: 443 444 .data 445 .globl szsigcode 446szsigcode: 447 .long esigcode-sigcode 448#ifdef COMPAT_FREEBSD4 449 .globl szfreebsd4_sigcode 450szfreebsd4_sigcode: 451 .long esigcode-freebsd4_sigcode 452#endif 453#ifdef COMPAT_43 454 .globl szosigcode 455szosigcode: 456 .long esigcode-osigcode 457#endif 458 .text 459 460/********************************************************************** 461 * 462 * Recover the bootinfo passed to us from the boot program 463 * 464 */ 465recover_bootinfo: 466 /* 467 * This code is called in different ways depending on what loaded 468 * and started the kernel. This is used to detect how we get the 469 * arguments from the other code and what we do with them. 470 * 471 * Old disk boot blocks: 472 * (*btext)(howto, bootdev, cyloffset, esym); 473 * [return address == 0, and can NOT be returned to] 474 * [cyloffset was not supported by the FreeBSD boot code 475 * and always passed in as 0] 476 * [esym is also known as total in the boot code, and 477 * was never properly supported by the FreeBSD boot code] 478 * 479 * Old diskless netboot code: 480 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 481 * [return address != 0, and can NOT be returned to] 482 * If we are being booted by this code it will NOT work, 483 * so we are just going to halt if we find this case. 484 * 485 * New uniform boot code: 486 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 487 * [return address != 0, and can be returned to] 488 * 489 * There may seem to be a lot of wasted arguments in here, but 490 * that is so the newer boot code can still load very old kernels 491 * and old boot code can load new kernels. 492 */ 493 494 /* 495 * The old style disk boot blocks fake a frame on the stack and 496 * did an lret to get here. The frame on the stack has a return 497 * address of 0. 498 */ 499 cmpl $0,4(%ebp) 500 je olddiskboot 501 502 /* 503 * We have some form of return address, so this is either the 504 * old diskless netboot code, or the new uniform code. That can 505 * be detected by looking at the 5th argument, if it is 0 506 * we are being booted by the new uniform boot code. 507 */ 508 cmpl $0,24(%ebp) 509 je newboot 510 511 /* 512 * Seems we have been loaded by the old diskless boot code, we 513 * don't stand a chance of running as the diskless structure 514 * changed considerably between the two, so just halt. 515 */ 516 hlt 517 518 /* 519 * We have been loaded by the new uniform boot code. 520 * Let's check the bootinfo version, and if we do not understand 521 * it we return to the loader with a status of 1 to indicate this error 522 */ 523newboot: 524 movl 28(%ebp),%ebx /* &bootinfo.version */ 525 movl BI_VERSION(%ebx),%eax 526 cmpl $1,%eax /* We only understand version 1 */ 527 je 1f 528 movl $1,%eax /* Return status */ 529 leave 530 /* 531 * XXX this returns to our caller's caller (as is required) since 532 * we didn't set up a frame and our caller did. 533 */ 534 ret 535 5361: 537 /* 538 * If we have a kernelname copy it in 539 */ 540 movl BI_KERNELNAME(%ebx),%esi 541 cmpl $0,%esi 542 je 2f /* No kernelname */ 543 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 544 movl $R(kernelname),%edi 545 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 546 je 1f 547 movb $'/',(%edi) 548 incl %edi 549 decl %ecx 5501: 551 cld 552 rep 553 movsb 554 5552: 556 /* 557 * Determine the size of the boot loader's copy of the bootinfo 558 * struct. This is impossible to do properly because old versions 559 * of the struct don't contain a size field and there are 2 old 560 * versions with the same version number. 561 */ 562 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 563 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 564 je got_bi_size /* no, sizeless version */ 565 movl BI_SIZE(%ebx),%ecx 566got_bi_size: 567 568 /* 569 * Copy the common part of the bootinfo struct 570 */ 571 movl %ebx,%esi 572 movl $R(bootinfo),%edi 573 cmpl $BOOTINFO_SIZE,%ecx 574 jbe got_common_bi_size 575 movl $BOOTINFO_SIZE,%ecx 576got_common_bi_size: 577 cld 578 rep 579 movsb 580 581#ifdef NFS_ROOT 582#ifndef BOOTP_NFSV3 583 /* 584 * If we have a nfs_diskless structure copy it in 585 */ 586 movl BI_NFS_DISKLESS(%ebx),%esi 587 cmpl $0,%esi 588 je olddiskboot 589 movl $R(nfs_diskless),%edi 590 movl $NFSDISKLESS_SIZE,%ecx 591 cld 592 rep 593 movsb 594 movl $R(nfs_diskless_valid),%edi 595 movl $1,(%edi) 596#endif 597#endif 598 599 /* 600 * The old style disk boot. 601 * (*btext)(howto, bootdev, cyloffset, esym); 602 * Note that the newer boot code just falls into here to pick 603 * up howto and bootdev, cyloffset and esym are no longer used 604 */ 605olddiskboot: 606 movl 8(%ebp),%eax 607 movl %eax,R(boothowto) 608 movl 12(%ebp),%eax 609 movl %eax,R(bootdev) 610 611 ret 612 613 614/********************************************************************** 615 * 616 * Identify the CPU and initialize anything special about it 617 * 618 */ 619identify_cpu: 620 621 /* Try to toggle alignment check flag; does not exist on 386. */ 622 pushfl 623 popl %eax 624 movl %eax,%ecx 625 orl $PSL_AC,%eax 626 pushl %eax 627 popfl 628 pushfl 629 popl %eax 630 xorl %ecx,%eax 631 andl $PSL_AC,%eax 632 pushl %ecx 633 popfl 634 635 testl %eax,%eax 636 jnz try486 637 638 /* NexGen CPU does not have aligment check flag. */ 639 pushfl 640 movl $0x5555, %eax 641 xorl %edx, %edx 642 movl $2, %ecx 643 clc 644 divl %ecx 645 jz trynexgen 646 popfl 647 movl $CPU_386,R(cpu) 648 jmp 3f 649 650trynexgen: 651 popfl 652 movl $CPU_NX586,R(cpu) 653 movl $0x4778654e,R(cpu_vendor) # store vendor string 654 movl $0x72446e65,R(cpu_vendor+4) 655 movl $0x6e657669,R(cpu_vendor+8) 656 movl $0,R(cpu_vendor+12) 657 jmp 3f 658 659try486: /* Try to toggle identification flag; does not exist on early 486s. */ 660 pushfl 661 popl %eax 662 movl %eax,%ecx 663 xorl $PSL_ID,%eax 664 pushl %eax 665 popfl 666 pushfl 667 popl %eax 668 xorl %ecx,%eax 669 andl $PSL_ID,%eax 670 pushl %ecx 671 popfl 672 673 testl %eax,%eax 674 jnz trycpuid 675 movl $CPU_486,R(cpu) 676 677 /* 678 * Check Cyrix CPU 679 * Cyrix CPUs do not change the undefined flags following 680 * execution of the divide instruction which divides 5 by 2. 681 * 682 * Note: CPUID is enabled on M2, so it passes another way. 683 */ 684 pushfl 685 movl $0x5555, %eax 686 xorl %edx, %edx 687 movl $2, %ecx 688 clc 689 divl %ecx 690 jnc trycyrix 691 popfl 692 jmp 3f /* You may use Intel CPU. */ 693 694trycyrix: 695 popfl 696 /* 697 * IBM Bluelighting CPU also doesn't change the undefined flags. 698 * Because IBM doesn't disclose the information for Bluelighting 699 * CPU, we couldn't distinguish it from Cyrix's (including IBM 700 * brand of Cyrix CPUs). 701 */ 702 movl $0x69727943,R(cpu_vendor) # store vendor string 703 movl $0x736e4978,R(cpu_vendor+4) 704 movl $0x64616574,R(cpu_vendor+8) 705 jmp 3f 706 707trycpuid: /* Use the `cpuid' instruction. */ 708 xorl %eax,%eax 709 cpuid # cpuid 0 710 movl %eax,R(cpu_high) # highest capability 711 movl %ebx,R(cpu_vendor) # store vendor string 712 movl %edx,R(cpu_vendor+4) 713 movl %ecx,R(cpu_vendor+8) 714 movb $0,R(cpu_vendor+12) 715 716 movl $1,%eax 717 cpuid # cpuid 1 718 movl %eax,R(cpu_id) # store cpu_id 719 movl %edx,R(cpu_feature) # store cpu_feature 720 rorl $8,%eax # extract family type 721 andl $15,%eax 722 cmpl $5,%eax 723 jae 1f 724 725 /* less than Pentium; must be 486 */ 726 movl $CPU_486,R(cpu) 727 jmp 3f 7281: 729 /* a Pentium? */ 730 cmpl $5,%eax 731 jne 2f 732 movl $CPU_586,R(cpu) 733 jmp 3f 7342: 735 /* Greater than Pentium...call it a Pentium Pro */ 736 movl $CPU_686,R(cpu) 7373: 738 ret 739 740 741/********************************************************************** 742 * 743 * Create the first page directory and its page tables. 744 * 745 */ 746 747create_pagetables: 748 749/* Find end of kernel image (rounded up to a page boundary). */ 750 movl $R(_end),%esi 751 752/* Include symbols, if any. */ 753 movl R(bootinfo+BI_ESYMTAB),%edi 754 testl %edi,%edi 755 je over_symalloc 756 movl %edi,%esi 757 movl $KERNBASE,%edi 758 addl %edi,R(bootinfo+BI_SYMTAB) 759 addl %edi,R(bootinfo+BI_ESYMTAB) 760over_symalloc: 761 762/* If we are told where the end of the kernel space is, believe it. */ 763 movl R(bootinfo+BI_KERNEND),%edi 764 testl %edi,%edi 765 je no_kernend 766 movl %edi,%esi 767no_kernend: 768 769 addl $PAGE_MASK,%esi 770 andl $~PAGE_MASK,%esi 771 movl %esi,R(KERNend) /* save end of kernel */ 772 movl %esi,R(physfree) /* next free page is at end of kernel */ 773 774/* Allocate Kernel Page Tables */ 775 ALLOCPAGES(NKPT) 776 movl %esi,R(KPTphys) 777 778/* Allocate Page Table Directory */ 779 ALLOCPAGES(1) 780 movl %esi,R(IdlePTD) 781 782/* Allocate UPAGES */ 783 ALLOCPAGES(UAREA_PAGES) 784 movl %esi,R(p0upa) 785 addl $KERNBASE, %esi 786 movl %esi, R(proc0uarea) 787 788 ALLOCPAGES(KSTACK_PAGES) 789 movl %esi,R(p0kpa) 790 addl $KERNBASE, %esi 791 movl %esi, R(proc0kstack) 792 793 ALLOCPAGES(1) /* vm86/bios stack */ 794 movl %esi,R(vm86phystk) 795 796 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 797 movl %esi,R(vm86pa) 798 addl $KERNBASE, %esi 799 movl %esi, R(vm86paddr) 800 801#ifdef SMP 802/* Allocate cpu0's private data page */ 803 ALLOCPAGES(1) 804 movl %esi,R(cpu0pp) 805 addl $KERNBASE, %esi 806 movl %esi, R(cpu0prvpage) /* relocated to KVM space */ 807 808/* Allocate SMP page table page */ 809 ALLOCPAGES(1) 810 movl %esi,R(SMPptpa) 811 addl $KERNBASE, %esi 812 movl %esi, R(SMPpt) /* relocated to KVM space */ 813#endif /* SMP */ 814 815/* Map read-only from zero to the end of the kernel text section */ 816 xorl %eax, %eax 817#ifdef BDE_DEBUGGER 818/* If the debugger is present, actually map everything read-write. */ 819 cmpl $0,R(_bdb_exists) 820 jne map_read_write 821#endif 822 xorl %edx,%edx 823 movl $R(etext),%ecx 824 addl $PAGE_MASK,%ecx 825 shrl $PAGE_SHIFT,%ecx 826 fillkptphys(%edx) 827 828/* Map read-write, data, bss and symbols */ 829 movl $R(etext),%eax 830 addl $PAGE_MASK, %eax 831 andl $~PAGE_MASK, %eax 832map_read_write: 833 movl $PG_RW,%edx 834 movl R(KERNend),%ecx 835 subl %eax,%ecx 836 shrl $PAGE_SHIFT,%ecx 837 fillkptphys(%edx) 838 839/* Map page directory. */ 840 movl R(IdlePTD), %eax 841 movl $1, %ecx 842 fillkptphys($PG_RW) 843 844/* Map proc0's UPAGES in the physical way ... */ 845 movl R(p0upa), %eax 846 movl $(UAREA_PAGES), %ecx 847 fillkptphys($PG_RW) 848 849/* Map proc0's KSTACK in the physical way ... */ 850 movl R(p0kpa), %eax 851 movl $(KSTACK_PAGES), %ecx 852 fillkptphys($PG_RW) 853 854/* Map ISA hole */ 855 movl $ISA_HOLE_START, %eax 856 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 857 fillkptphys($PG_RW) 858 859/* Map space for the vm86 region */ 860 movl R(vm86phystk), %eax 861 movl $4, %ecx 862 fillkptphys($PG_RW) 863 864/* Map page 0 into the vm86 page table */ 865 movl $0, %eax 866 movl $0, %ebx 867 movl $1, %ecx 868 fillkpt(R(vm86pa), $PG_RW|PG_U) 869 870/* ...likewise for the ISA hole */ 871 movl $ISA_HOLE_START, %eax 872 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 873 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 874 fillkpt(R(vm86pa), $PG_RW|PG_U) 875 876#ifdef SMP 877/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 878 movl R(cpu0pp), %eax 879 movl $1, %ecx 880 fillkptphys($PG_RW) 881 882/* Map SMP page table page into global kmem FWIW */ 883 movl R(SMPptpa), %eax 884 movl $1, %ecx 885 fillkptphys($PG_RW) 886 887/* Map the private page into the SMP page table */ 888 movl R(cpu0pp), %eax 889 movl $0, %ebx /* pte offset = 0 */ 890 movl $1, %ecx /* one private page coming right up */ 891 fillkpt(R(SMPptpa), $PG_RW) 892 893/* ... and put the page table table in the pde. */ 894 movl R(SMPptpa), %eax 895 movl $MPPTDI, %ebx 896 movl $1, %ecx 897 fillkpt(R(IdlePTD), $PG_RW) 898 899/* Fakeup VA for the local apic to allow early traps. */ 900 ALLOCPAGES(1) 901 movl %esi, %eax 902 movl $(NPTEPG-1), %ebx /* pte offset = NTEPG-1 */ 903 movl $1, %ecx /* one private pt coming right up */ 904 fillkpt(R(SMPptpa), $PG_RW) 905#endif /* SMP */ 906 907/* install a pde for temporary double map of bottom of VA */ 908 movl R(KPTphys), %eax 909 xorl %ebx, %ebx 910 movl $NKPT, %ecx 911 fillkpt(R(IdlePTD), $PG_RW) 912 913/* install pde's for pt's */ 914 movl R(KPTphys), %eax 915 movl $KPTDI, %ebx 916 movl $NKPT, %ecx 917 fillkpt(R(IdlePTD), $PG_RW) 918 919/* install a pde recursively mapping page directory as a page table */ 920 movl R(IdlePTD), %eax 921 movl $PTDPTDI, %ebx 922 movl $1,%ecx 923 fillkpt(R(IdlePTD), $PG_RW) 924 925 ret 926 927#ifdef BDE_DEBUGGER 928bdb_prepare_paging: 929 cmpl $0,R(_bdb_exists) 930 je bdb_prepare_paging_exit 931 932 subl $6,%esp 933 934 /* 935 * Copy and convert debugger entries from the bootstrap gdt and idt 936 * to the kernel gdt and idt. Everything is still in low memory. 937 * Tracing continues to work after paging is enabled because the 938 * low memory addresses remain valid until everything is relocated. 939 * However, tracing through the setidt() that initializes the trace 940 * trap will crash. 941 */ 942 sgdt (%esp) 943 movl 2(%esp),%esi /* base address of bootstrap gdt */ 944 movl $R(_gdt),%edi 945 movl %edi,2(%esp) /* prepare to load kernel gdt */ 946 movl $8*18/4,%ecx 947 cld 948 rep /* copy gdt */ 949 movsl 950 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 951 movb $0x92,-8+5(%edi) 952 lgdt (%esp) 953 954 sidt (%esp) 955 movl 2(%esp),%esi /* base address of current idt */ 956 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 957 movw 8(%esi),%ax 958 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 959 movl 8+2(%esi),%eax 960 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 961 movl 24+4(%esi),%eax /* same for bpt descriptor */ 962 movw 24(%esi),%ax 963 movl %eax,R(bdb_bpt_ljmp+1) 964 movl 24+2(%esi),%eax 965 movw %ax,R(bdb_bpt_ljmp+5) 966 movl R(_idt),%edi 967 movl %edi,2(%esp) /* prepare to load kernel idt */ 968 movl $8*4/4,%ecx 969 cld 970 rep /* copy idt */ 971 movsl 972 lidt (%esp) 973 974 addl $6,%esp 975 976bdb_prepare_paging_exit: 977 ret 978 979/* Relocate debugger gdt entries and gdt and idt pointers. */ 980bdb_commit_paging: 981 cmpl $0,_bdb_exists 982 je bdb_commit_paging_exit 983 984 movl $gdt+8*9,%eax /* adjust slots 9-17 */ 985 movl $9,%ecx 986reloc_gdt: 987 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 988 addl $8,%eax /* now KERNBASE>>24 */ 989 loop reloc_gdt 990 991 subl $6,%esp 992 sgdt (%esp) 993 addl $KERNBASE,2(%esp) 994 lgdt (%esp) 995 sidt (%esp) 996 addl $KERNBASE,2(%esp) 997 lidt (%esp) 998 addl $6,%esp 999 1000 int $3 1001 1002bdb_commit_paging_exit: 1003 ret 1004 1005#endif /* BDE_DEBUGGER */ 1006