locore.s revision 82262
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 82262 2001-08-24 08:29:54Z 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 * Compiled KERNBASE location 105 */ 106 .globl kernbase 107 .set kernbase,KERNBASE 108 109/* 110 * Globals 111 */ 112 .data 113 ALIGN_DATA /* just to be sure */ 114 115 .globl HIDENAME(tmpstk) 116 .space 0x2000 /* space for tmpstk - temporary stack */ 117HIDENAME(tmpstk): 118 119 .globl boothowto,bootdev 120 121 .globl cpu,cpu_vendor,cpu_id,bootinfo 122 .globl cpu_high, cpu_feature 123 124cpu: .long 0 /* are we 386, 386sx, or 486 */ 125cpu_id: .long 0 /* stepping ID */ 126cpu_high: .long 0 /* highest arg to CPUID */ 127cpu_feature: .long 0 /* features */ 128cpu_vendor: .space 20 /* CPU origin code */ 129bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 130 131KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 132physfree: .long 0 /* phys addr of next free page */ 133 134#ifdef SMP 135 .globl cpu0prvpage 136cpu0pp: .long 0 /* phys addr cpu0 private pg */ 137cpu0prvpage: .long 0 /* relocated version */ 138 139 .globl SMPpt 140SMPptpa: .long 0 /* phys addr SMP page table */ 141SMPpt: .long 0 /* relocated version */ 142#endif /* SMP */ 143 144 .globl IdlePTD 145IdlePTD: .long 0 /* phys addr of kernel PTD */ 146 147#ifdef SMP 148 .globl KPTphys 149#endif 150KPTphys: .long 0 /* phys addr of kernel page tables */ 151 152 .globl proc0paddr 153proc0paddr: .long 0 /* address of proc 0 address space */ 154p0upa: .long 0 /* phys addr of proc0's UPAGES */ 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 proc0paddr,%eax /* location of in-kernel pages */ 375 leal UPAGES*PAGE_SIZE(%eax),%esp /* bootstrap stack end location */ 376 377 xorl %ebp,%ebp /* mark end of frames */ 378 379 movl IdlePTD,%esi 380 movl %esi,PCB_CR3(%eax) 381 382 testl $CPUID_PGE, R(cpu_feature) 383 jz 1f 384 movl %cr4, %eax 385 orl $CR4_PGE, %eax 386 movl %eax, %cr4 3871: 388 pushl physfree /* value of first for init386(first) */ 389 call init386 /* wire 386 chip for unix operation */ 390 391 /* 392 * Clean up the stack in a way that db_numargs() understands, so 393 * that backtraces in ddb don't underrun the stack. Traps for 394 * inaccessible memory are more fatal than usual this early. 395 */ 396 addl $4,%esp 397 398 call mi_startup /* autoconfiguration, mountroot etc */ 399 /* NOTREACHED */ 400 addl $0,%esp /* for db_numargs() again */ 401 402/* 403 * Signal trampoline, copied to top of user stack 404 */ 405NON_GPROF_ENTRY(sigcode) 406 call *SIGF_HANDLER(%esp) /* call signal handler */ 407 lea SIGF_UC(%esp),%eax /* get ucontext_t */ 408 pushl %eax 409 testl $PSL_VM,UC_EFLAGS(%eax) 410 jne 9f 411 movl UC_GS(%eax),%gs /* restore %gs */ 4129: 413 movl $SYS_sigreturn,%eax 414 pushl %eax /* junk to fake return addr. */ 415 int $0x80 /* enter kernel with args */ 4160: jmp 0b 417 418 ALIGN_TEXT 419osigcode: 420 call *SIGF_HANDLER(%esp) /* call signal handler */ 421 lea SIGF_SC(%esp),%eax /* get sigcontext */ 422 pushl %eax 423 testl $PSL_VM,SC_PS(%eax) 424 jne 9f 425 movl SC_GS(%eax),%gs /* restore %gs */ 4269: 427 movl $0x01d516,SC_TRAPNO(%eax) /* magic: 0ldSiG */ 428 movl $SYS_sigreturn,%eax 429 pushl %eax /* junk to fake return addr. */ 430 int $0x80 /* enter kernel with args */ 4310: jmp 0b 432 433 ALIGN_TEXT 434esigcode: 435 436 .data 437 .globl szsigcode, szosigcode 438szsigcode: 439 .long esigcode-sigcode 440szosigcode: 441 .long esigcode-osigcode 442 .text 443 444/********************************************************************** 445 * 446 * Recover the bootinfo passed to us from the boot program 447 * 448 */ 449recover_bootinfo: 450 /* 451 * This code is called in different ways depending on what loaded 452 * and started the kernel. This is used to detect how we get the 453 * arguments from the other code and what we do with them. 454 * 455 * Old disk boot blocks: 456 * (*btext)(howto, bootdev, cyloffset, esym); 457 * [return address == 0, and can NOT be returned to] 458 * [cyloffset was not supported by the FreeBSD boot code 459 * and always passed in as 0] 460 * [esym is also known as total in the boot code, and 461 * was never properly supported by the FreeBSD boot code] 462 * 463 * Old diskless netboot code: 464 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 465 * [return address != 0, and can NOT be returned to] 466 * If we are being booted by this code it will NOT work, 467 * so we are just going to halt if we find this case. 468 * 469 * New uniform boot code: 470 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 471 * [return address != 0, and can be returned to] 472 * 473 * There may seem to be a lot of wasted arguments in here, but 474 * that is so the newer boot code can still load very old kernels 475 * and old boot code can load new kernels. 476 */ 477 478 /* 479 * The old style disk boot blocks fake a frame on the stack and 480 * did an lret to get here. The frame on the stack has a return 481 * address of 0. 482 */ 483 cmpl $0,4(%ebp) 484 je olddiskboot 485 486 /* 487 * We have some form of return address, so this is either the 488 * old diskless netboot code, or the new uniform code. That can 489 * be detected by looking at the 5th argument, if it is 0 490 * we are being booted by the new uniform boot code. 491 */ 492 cmpl $0,24(%ebp) 493 je newboot 494 495 /* 496 * Seems we have been loaded by the old diskless boot code, we 497 * don't stand a chance of running as the diskless structure 498 * changed considerably between the two, so just halt. 499 */ 500 hlt 501 502 /* 503 * We have been loaded by the new uniform boot code. 504 * Let's check the bootinfo version, and if we do not understand 505 * it we return to the loader with a status of 1 to indicate this error 506 */ 507newboot: 508 movl 28(%ebp),%ebx /* &bootinfo.version */ 509 movl BI_VERSION(%ebx),%eax 510 cmpl $1,%eax /* We only understand version 1 */ 511 je 1f 512 movl $1,%eax /* Return status */ 513 leave 514 /* 515 * XXX this returns to our caller's caller (as is required) since 516 * we didn't set up a frame and our caller did. 517 */ 518 ret 519 5201: 521 /* 522 * If we have a kernelname copy it in 523 */ 524 movl BI_KERNELNAME(%ebx),%esi 525 cmpl $0,%esi 526 je 2f /* No kernelname */ 527 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 528 movl $R(kernelname),%edi 529 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 530 je 1f 531 movb $'/',(%edi) 532 incl %edi 533 decl %ecx 5341: 535 cld 536 rep 537 movsb 538 5392: 540 /* 541 * Determine the size of the boot loader's copy of the bootinfo 542 * struct. This is impossible to do properly because old versions 543 * of the struct don't contain a size field and there are 2 old 544 * versions with the same version number. 545 */ 546 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 547 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 548 je got_bi_size /* no, sizeless version */ 549 movl BI_SIZE(%ebx),%ecx 550got_bi_size: 551 552 /* 553 * Copy the common part of the bootinfo struct 554 */ 555 movl %ebx,%esi 556 movl $R(bootinfo),%edi 557 cmpl $BOOTINFO_SIZE,%ecx 558 jbe got_common_bi_size 559 movl $BOOTINFO_SIZE,%ecx 560got_common_bi_size: 561 cld 562 rep 563 movsb 564 565#ifdef NFS_ROOT 566#ifndef BOOTP_NFSV3 567 /* 568 * If we have a nfs_diskless structure copy it in 569 */ 570 movl BI_NFS_DISKLESS(%ebx),%esi 571 cmpl $0,%esi 572 je olddiskboot 573 movl $R(nfs_diskless),%edi 574 movl $NFSDISKLESS_SIZE,%ecx 575 cld 576 rep 577 movsb 578 movl $R(nfs_diskless_valid),%edi 579 movl $1,(%edi) 580#endif 581#endif 582 583 /* 584 * The old style disk boot. 585 * (*btext)(howto, bootdev, cyloffset, esym); 586 * Note that the newer boot code just falls into here to pick 587 * up howto and bootdev, cyloffset and esym are no longer used 588 */ 589olddiskboot: 590 movl 8(%ebp),%eax 591 movl %eax,R(boothowto) 592 movl 12(%ebp),%eax 593 movl %eax,R(bootdev) 594 595 ret 596 597 598/********************************************************************** 599 * 600 * Identify the CPU and initialize anything special about it 601 * 602 */ 603identify_cpu: 604 605 /* Try to toggle alignment check flag; does not exist on 386. */ 606 pushfl 607 popl %eax 608 movl %eax,%ecx 609 orl $PSL_AC,%eax 610 pushl %eax 611 popfl 612 pushfl 613 popl %eax 614 xorl %ecx,%eax 615 andl $PSL_AC,%eax 616 pushl %ecx 617 popfl 618 619 testl %eax,%eax 620 jnz try486 621 622 /* NexGen CPU does not have aligment check flag. */ 623 pushfl 624 movl $0x5555, %eax 625 xorl %edx, %edx 626 movl $2, %ecx 627 clc 628 divl %ecx 629 jz trynexgen 630 popfl 631 movl $CPU_386,R(cpu) 632 jmp 3f 633 634trynexgen: 635 popfl 636 movl $CPU_NX586,R(cpu) 637 movl $0x4778654e,R(cpu_vendor) # store vendor string 638 movl $0x72446e65,R(cpu_vendor+4) 639 movl $0x6e657669,R(cpu_vendor+8) 640 movl $0,R(cpu_vendor+12) 641 jmp 3f 642 643try486: /* Try to toggle identification flag; does not exist on early 486s. */ 644 pushfl 645 popl %eax 646 movl %eax,%ecx 647 xorl $PSL_ID,%eax 648 pushl %eax 649 popfl 650 pushfl 651 popl %eax 652 xorl %ecx,%eax 653 andl $PSL_ID,%eax 654 pushl %ecx 655 popfl 656 657 testl %eax,%eax 658 jnz trycpuid 659 movl $CPU_486,R(cpu) 660 661 /* 662 * Check Cyrix CPU 663 * Cyrix CPUs do not change the undefined flags following 664 * execution of the divide instruction which divides 5 by 2. 665 * 666 * Note: CPUID is enabled on M2, so it passes another way. 667 */ 668 pushfl 669 movl $0x5555, %eax 670 xorl %edx, %edx 671 movl $2, %ecx 672 clc 673 divl %ecx 674 jnc trycyrix 675 popfl 676 jmp 3f /* You may use Intel CPU. */ 677 678trycyrix: 679 popfl 680 /* 681 * IBM Bluelighting CPU also doesn't change the undefined flags. 682 * Because IBM doesn't disclose the information for Bluelighting 683 * CPU, we couldn't distinguish it from Cyrix's (including IBM 684 * brand of Cyrix CPUs). 685 */ 686 movl $0x69727943,R(cpu_vendor) # store vendor string 687 movl $0x736e4978,R(cpu_vendor+4) 688 movl $0x64616574,R(cpu_vendor+8) 689 jmp 3f 690 691trycpuid: /* Use the `cpuid' instruction. */ 692 xorl %eax,%eax 693 cpuid # cpuid 0 694 movl %eax,R(cpu_high) # highest capability 695 movl %ebx,R(cpu_vendor) # store vendor string 696 movl %edx,R(cpu_vendor+4) 697 movl %ecx,R(cpu_vendor+8) 698 movb $0,R(cpu_vendor+12) 699 700 movl $1,%eax 701 cpuid # cpuid 1 702 movl %eax,R(cpu_id) # store cpu_id 703 movl %edx,R(cpu_feature) # store cpu_feature 704 rorl $8,%eax # extract family type 705 andl $15,%eax 706 cmpl $5,%eax 707 jae 1f 708 709 /* less than Pentium; must be 486 */ 710 movl $CPU_486,R(cpu) 711 jmp 3f 7121: 713 /* a Pentium? */ 714 cmpl $5,%eax 715 jne 2f 716 movl $CPU_586,R(cpu) 717 jmp 3f 7182: 719 /* Greater than Pentium...call it a Pentium Pro */ 720 movl $CPU_686,R(cpu) 7213: 722 ret 723 724 725/********************************************************************** 726 * 727 * Create the first page directory and its page tables. 728 * 729 */ 730 731create_pagetables: 732 733/* Find end of kernel image (rounded up to a page boundary). */ 734 movl $R(_end),%esi 735 736/* Include symbols, if any. */ 737 movl R(bootinfo+BI_ESYMTAB),%edi 738 testl %edi,%edi 739 je over_symalloc 740 movl %edi,%esi 741 movl $KERNBASE,%edi 742 addl %edi,R(bootinfo+BI_SYMTAB) 743 addl %edi,R(bootinfo+BI_ESYMTAB) 744over_symalloc: 745 746/* If we are told where the end of the kernel space is, believe it. */ 747 movl R(bootinfo+BI_KERNEND),%edi 748 testl %edi,%edi 749 je no_kernend 750 movl %edi,%esi 751no_kernend: 752 753 addl $PAGE_MASK,%esi 754 andl $~PAGE_MASK,%esi 755 movl %esi,R(KERNend) /* save end of kernel */ 756 movl %esi,R(physfree) /* next free page is at end of kernel */ 757 758/* Allocate Kernel Page Tables */ 759 ALLOCPAGES(NKPT) 760 movl %esi,R(KPTphys) 761 762/* Allocate Page Table Directory */ 763 ALLOCPAGES(1) 764 movl %esi,R(IdlePTD) 765 766/* Allocate UPAGES */ 767 ALLOCPAGES(UPAGES) 768 movl %esi,R(p0upa) 769 addl $KERNBASE, %esi 770 movl %esi, R(proc0paddr) 771 772 ALLOCPAGES(1) /* vm86/bios stack */ 773 movl %esi,R(vm86phystk) 774 775 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 776 movl %esi,R(vm86pa) 777 addl $KERNBASE, %esi 778 movl %esi, R(vm86paddr) 779 780#ifdef SMP 781/* Allocate cpu0's private data page */ 782 ALLOCPAGES(1) 783 movl %esi,R(cpu0pp) 784 addl $KERNBASE, %esi 785 movl %esi, R(cpu0prvpage) /* relocated to KVM space */ 786 787/* Allocate SMP page table page */ 788 ALLOCPAGES(1) 789 movl %esi,R(SMPptpa) 790 addl $KERNBASE, %esi 791 movl %esi, R(SMPpt) /* relocated to KVM space */ 792#endif /* SMP */ 793 794/* Map read-only from zero to the end of the kernel text section */ 795 xorl %eax, %eax 796#ifdef BDE_DEBUGGER 797/* If the debugger is present, actually map everything read-write. */ 798 cmpl $0,R(_bdb_exists) 799 jne map_read_write 800#endif 801 xorl %edx,%edx 802 803#if !defined(SMP) 804 testl $CPUID_PGE, R(cpu_feature) 805 jz 2f 806 orl $PG_G,%edx 807#endif 808 8092: movl $R(etext),%ecx 810 addl $PAGE_MASK,%ecx 811 shrl $PAGE_SHIFT,%ecx 812 fillkptphys(%edx) 813 814/* Map read-write, data, bss and symbols */ 815 movl $R(etext),%eax 816 addl $PAGE_MASK, %eax 817 andl $~PAGE_MASK, %eax 818map_read_write: 819 movl $PG_RW,%edx 820#if !defined(SMP) 821 testl $CPUID_PGE, R(cpu_feature) 822 jz 1f 823 orl $PG_G,%edx 824#endif 825 8261: movl R(KERNend),%ecx 827 subl %eax,%ecx 828 shrl $PAGE_SHIFT,%ecx 829 fillkptphys(%edx) 830 831/* Map page directory. */ 832 movl R(IdlePTD), %eax 833 movl $1, %ecx 834 fillkptphys($PG_RW) 835 836/* Map proc0's UPAGES in the physical way ... */ 837 movl R(p0upa), %eax 838 movl $UPAGES, %ecx 839 fillkptphys($PG_RW) 840 841/* Map ISA hole */ 842 movl $ISA_HOLE_START, %eax 843 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 844 fillkptphys($PG_RW) 845 846/* Map space for the vm86 region */ 847 movl R(vm86phystk), %eax 848 movl $4, %ecx 849 fillkptphys($PG_RW) 850 851/* Map page 0 into the vm86 page table */ 852 movl $0, %eax 853 movl $0, %ebx 854 movl $1, %ecx 855 fillkpt(R(vm86pa), $PG_RW|PG_U) 856 857/* ...likewise for the ISA hole */ 858 movl $ISA_HOLE_START, %eax 859 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 860 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 861 fillkpt(R(vm86pa), $PG_RW|PG_U) 862 863#ifdef SMP 864/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 865 movl R(cpu0pp), %eax 866 movl $1, %ecx 867 fillkptphys($PG_RW) 868 869/* Map SMP page table page into global kmem FWIW */ 870 movl R(SMPptpa), %eax 871 movl $1, %ecx 872 fillkptphys($PG_RW) 873 874/* Map the private page into the SMP page table */ 875 movl R(cpu0pp), %eax 876 movl $0, %ebx /* pte offset = 0 */ 877 movl $1, %ecx /* one private page coming right up */ 878 fillkpt(R(SMPptpa), $PG_RW) 879 880/* ... and put the page table table in the pde. */ 881 movl R(SMPptpa), %eax 882 movl $MPPTDI, %ebx 883 movl $1, %ecx 884 fillkpt(R(IdlePTD), $PG_RW) 885 886/* Fakeup VA for the local apic to allow early traps. */ 887 ALLOCPAGES(1) 888 movl %esi, %eax 889 movl $(NPTEPG-1), %ebx /* pte offset = NTEPG-1 */ 890 movl $1, %ecx /* one private pt coming right up */ 891 fillkpt(R(SMPptpa), $PG_RW) 892#endif /* SMP */ 893 894/* install a pde for temporary double map of bottom of VA */ 895 movl R(KPTphys), %eax 896 xorl %ebx, %ebx 897 movl $NKPT, %ecx 898 fillkpt(R(IdlePTD), $PG_RW) 899 900/* install pde's for pt's */ 901 movl R(KPTphys), %eax 902 movl $KPTDI, %ebx 903 movl $NKPT, %ecx 904 fillkpt(R(IdlePTD), $PG_RW) 905 906/* install a pde recursively mapping page directory as a page table */ 907 movl R(IdlePTD), %eax 908 movl $PTDPTDI, %ebx 909 movl $1,%ecx 910 fillkpt(R(IdlePTD), $PG_RW) 911 912 ret 913 914#ifdef BDE_DEBUGGER 915bdb_prepare_paging: 916 cmpl $0,R(_bdb_exists) 917 je bdb_prepare_paging_exit 918 919 subl $6,%esp 920 921 /* 922 * Copy and convert debugger entries from the bootstrap gdt and idt 923 * to the kernel gdt and idt. Everything is still in low memory. 924 * Tracing continues to work after paging is enabled because the 925 * low memory addresses remain valid until everything is relocated. 926 * However, tracing through the setidt() that initializes the trace 927 * trap will crash. 928 */ 929 sgdt (%esp) 930 movl 2(%esp),%esi /* base address of bootstrap gdt */ 931 movl $R(_gdt),%edi 932 movl %edi,2(%esp) /* prepare to load kernel gdt */ 933 movl $8*18/4,%ecx 934 cld 935 rep /* copy gdt */ 936 movsl 937 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 938 movb $0x92,-8+5(%edi) 939 lgdt (%esp) 940 941 sidt (%esp) 942 movl 2(%esp),%esi /* base address of current idt */ 943 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 944 movw 8(%esi),%ax 945 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 946 movl 8+2(%esi),%eax 947 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 948 movl 24+4(%esi),%eax /* same for bpt descriptor */ 949 movw 24(%esi),%ax 950 movl %eax,R(bdb_bpt_ljmp+1) 951 movl 24+2(%esi),%eax 952 movw %ax,R(bdb_bpt_ljmp+5) 953 movl R(_idt),%edi 954 movl %edi,2(%esp) /* prepare to load kernel idt */ 955 movl $8*4/4,%ecx 956 cld 957 rep /* copy idt */ 958 movsl 959 lidt (%esp) 960 961 addl $6,%esp 962 963bdb_prepare_paging_exit: 964 ret 965 966/* Relocate debugger gdt entries and gdt and idt pointers. */ 967bdb_commit_paging: 968 cmpl $0,_bdb_exists 969 je bdb_commit_paging_exit 970 971 movl $gdt+8*9,%eax /* adjust slots 9-17 */ 972 movl $9,%ecx 973reloc_gdt: 974 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 975 addl $8,%eax /* now KERNBASE>>24 */ 976 loop reloc_gdt 977 978 subl $6,%esp 979 sgdt (%esp) 980 addl $KERNBASE,2(%esp) 981 lgdt (%esp) 982 sidt (%esp) 983 addl $KERNBASE,2(%esp) 984 lidt (%esp) 985 addl $6,%esp 986 987 int $3 988 989bdb_commit_paging_exit: 990 ret 991 992#endif /* BDE_DEBUGGER */ 993