locore.s revision 82140
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 82140 2001-08-22 15:41:43Z iwasaki $ 38 * 39 * originally from: locore.s, by William F. Jolitz 40 * 41 * Substantially rewritten by David Greenman, Rod Grimes, 42 * Bruce Evans, Wolfgang Solfrank, Poul-Henning Kamp 43 * and many others. 44 */ 45 46#include "opt_bootp.h" 47#include "opt_nfsroot.h" 48 49#include <sys/syscall.h> 50#include <sys/reboot.h> 51 52#include <machine/asmacros.h> 53#include <machine/cputypes.h> 54#include <machine/psl.h> 55#include <machine/pmap.h> 56#include <machine/specialreg.h> 57 58#include "assym.s" 59 60#ifdef __AOUT__ 61#define etext _etext 62#define edata _edata 63#define end _end 64#endif 65 66/* 67 * XXX 68 * 69 * Note: This version greatly munged to avoid various assembler errors 70 * that may be fixed in newer versions of gas. Perhaps newer versions 71 * will have more pleasant appearance. 72 */ 73 74/* 75 * PTmap is recursive pagemap at top of virtual address space. 76 * Within PTmap, the page directory can be found (third indirection). 77 */ 78 .globl PTmap,PTD,PTDpde 79 .set PTmap,(PTDPTDI << PDRSHIFT) 80 .set PTD,PTmap + (PTDPTDI * PAGE_SIZE) 81 .set PTDpde,PTD + (PTDPTDI * PDESIZE) 82 83/* 84 * APTmap, APTD is the alternate recursive pagemap. 85 * It's used when modifying another process's page tables. 86 */ 87 .globl APTmap,APTD,APTDpde 88 .set APTmap,APTDPTDI << PDRSHIFT 89 .set APTD,APTmap + (APTDPTDI * PAGE_SIZE) 90 .set APTDpde,PTD + (APTDPTDI * PDESIZE) 91 92#ifdef SMP 93/* 94 * Define layout of per-cpu address space. 95 * This is "constructed" in locore.s on the BSP and in mp_machdep.c 96 * for each AP. DO NOT REORDER THESE WITHOUT UPDATING THE REST! 97 */ 98 .globl SMP_prvspace, lapic 99 .set SMP_prvspace,(MPPTDI << PDRSHIFT) 100 .set lapic,SMP_prvspace + (NPTEPG-1) * PAGE_SIZE 101#endif /* SMP */ 102 103/* 104 * Globals 105 */ 106 .data 107 ALIGN_DATA /* just to be sure */ 108 109 .globl HIDENAME(tmpstk) 110 .space 0x2000 /* space for tmpstk - temporary stack */ 111HIDENAME(tmpstk): 112 113 .globl boothowto,bootdev 114 115 .globl cpu,cpu_vendor,cpu_id,bootinfo 116 .globl cpu_high, cpu_feature, cpu_fxsr 117 118cpu: .long 0 /* are we 386, 386sx, or 486 */ 119cpu_id: .long 0 /* stepping ID */ 120cpu_high: .long 0 /* highest arg to CPUID */ 121cpu_feature: .long 0 /* features */ 122cpu_fxsr: .long 0 /* use fxsave/fxrstor instruction */ 123cpu_vendor: .space 20 /* CPU origin code */ 124bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 125 126KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 127physfree: .long 0 /* phys addr of next free page */ 128 129#ifdef SMP 130 .globl cpu0prvpage 131cpu0pp: .long 0 /* phys addr cpu0 private pg */ 132cpu0prvpage: .long 0 /* relocated version */ 133 134 .globl SMPpt 135SMPptpa: .long 0 /* phys addr SMP page table */ 136SMPpt: .long 0 /* relocated version */ 137#endif /* SMP */ 138 139 .globl IdlePTD 140IdlePTD: .long 0 /* phys addr of kernel PTD */ 141 142#ifdef SMP 143 .globl KPTphys 144#endif 145KPTphys: .long 0 /* phys addr of kernel page tables */ 146 147 .globl proc0paddr 148proc0paddr: .long 0 /* address of proc 0 address space */ 149p0upa: .long 0 /* phys addr of proc0's UPAGES */ 150 151vm86phystk: .long 0 /* PA of vm86/bios stack */ 152 153 .globl vm86paddr, vm86pa 154vm86paddr: .long 0 /* address of vm86 region */ 155vm86pa: .long 0 /* phys addr of vm86 region */ 156 157#ifdef BDE_DEBUGGER 158 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 159_bdb_exists: .long 0 160#endif 161 162#ifdef PC98 163 .globl pc98_system_parameter 164pc98_system_parameter: 165 .space 0x240 166#endif 167 168/********************************************************************** 169 * 170 * Some handy macros 171 * 172 */ 173 174#define R(foo) ((foo)-KERNBASE) 175 176#define ALLOCPAGES(foo) \ 177 movl R(physfree), %esi ; \ 178 movl $((foo)*PAGE_SIZE), %eax ; \ 179 addl %esi, %eax ; \ 180 movl %eax, R(physfree) ; \ 181 movl %esi, %edi ; \ 182 movl $((foo)*PAGE_SIZE),%ecx ; \ 183 xorl %eax,%eax ; \ 184 cld ; \ 185 rep ; \ 186 stosb 187 188/* 189 * fillkpt 190 * eax = page frame address 191 * ebx = index into page table 192 * ecx = how many pages to map 193 * base = base address of page dir/table 194 * prot = protection bits 195 */ 196#define fillkpt(base, prot) \ 197 shll $2,%ebx ; \ 198 addl base,%ebx ; \ 199 orl $PG_V,%eax ; \ 200 orl prot,%eax ; \ 2011: movl %eax,(%ebx) ; \ 202 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 203 addl $4,%ebx ; /* next pte */ \ 204 loop 1b 205 206/* 207 * fillkptphys(prot) 208 * eax = physical address 209 * ecx = how many pages to map 210 * prot = protection bits 211 */ 212#define fillkptphys(prot) \ 213 movl %eax, %ebx ; \ 214 shrl $PAGE_SHIFT, %ebx ; \ 215 fillkpt(R(KPTphys), prot) 216 217 .text 218/********************************************************************** 219 * 220 * This is where the bootblocks start us, set the ball rolling... 221 * 222 */ 223NON_GPROF_ENTRY(btext) 224 225#ifdef PC98 226 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 227 movl $0xa1400,%esi 228 movl $R(pc98_system_parameter),%edi 229 movl $0x0240,%ecx 230 cld 231 rep 232 movsb 233#else /* IBM-PC */ 234#ifdef BDE_DEBUGGER 235#ifdef BIOS_STEALS_3K 236 cmpl $0x0375c339,0x95504 237#else 238 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 239#endif 240 jne 1f 241 movb $1,R(_bdb_exists) 2421: 243#endif 244/* Tell the bios to warmboot next time */ 245 movw $0x1234,0x472 246#endif /* PC98 */ 247 248/* Set up a real frame in case the double return in newboot is executed. */ 249 pushl %ebp 250 movl %esp, %ebp 251 252/* Don't trust what the BIOS gives for eflags. */ 253 pushl $PSL_KERNEL 254 popfl 255 256/* 257 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 258 * to set %cs, %ds, %es and %ss. 259 */ 260 mov %ds, %ax 261 mov %ax, %fs 262 mov %ax, %gs 263 264 call recover_bootinfo 265 266/* Get onto a stack that we can trust. */ 267/* 268 * XXX this step is delayed in case recover_bootinfo needs to return via 269 * the old stack, but it need not be, since recover_bootinfo actually 270 * returns via the old frame. 271 */ 272 movl $R(HIDENAME(tmpstk)),%esp 273 274#ifdef PC98 275 /* pc98_machine_type & M_EPSON_PC98 */ 276 testb $0x02,R(pc98_system_parameter)+220 277 jz 3f 278 /* epson_machine_id <= 0x0b */ 279 cmpb $0x0b,R(pc98_system_parameter)+224 280 ja 3f 281 282 /* count up memory */ 283 movl $0x100000,%eax /* next, talley remaining memory */ 284 movl $0xFFF-0x100,%ecx 2851: movl 0(%eax),%ebx /* save location to check */ 286 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 287 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 288 jne 2f 289 movl %ebx,0(%eax) /* restore memory */ 290 addl $PAGE_SIZE,%eax 291 loop 1b 2922: subl $0x100000,%eax 293 shrl $17,%eax 294 movb %al,R(pc98_system_parameter)+1 2953: 296 297 movw R(pc98_system_parameter+0x86),%ax 298 movw %ax,R(cpu_id) 299#endif 300 301 call identify_cpu 302 303/* clear bss */ 304/* 305 * XXX this should be done a little earlier. 306 * 307 * XXX we don't check that there is memory for our bss and page tables 308 * before using it. 309 * 310 * XXX the boot program somewhat bogusly clears the bss. We still have 311 * to do it in case we were unzipped by kzipboot. Then the boot program 312 * only clears kzipboot's bss. 313 * 314 * XXX the gdt and idt are still somewhere in the boot program. We 315 * depend on the convention that the boot program is below 1MB and we 316 * are above 1MB to keep the gdt and idt away from the bss and page 317 * tables. The idt is only used if BDE_DEBUGGER is enabled. 318 */ 319 movl $R(end),%ecx 320 movl $R(edata),%edi 321 subl %edi,%ecx 322 xorl %eax,%eax 323 cld 324 rep 325 stosb 326 327 call create_pagetables 328 329/* 330 * If the CPU has support for VME, turn it on. 331 */ 332 testl $CPUID_VME, R(cpu_feature) 333 jz 1f 334 movl %cr4, %eax 335 orl $CR4_VME, %eax 336 movl %eax, %cr4 3371: 338 339#ifdef BDE_DEBUGGER 340/* 341 * Adjust as much as possible for paging before enabling paging so that the 342 * adjustments can be traced. 343 */ 344 call bdb_prepare_paging 345#endif 346 347/* Now enable paging */ 348 movl R(IdlePTD), %eax 349 movl %eax,%cr3 /* load ptd addr into mmu */ 350 movl %cr0,%eax /* get control word */ 351 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 352 movl %eax,%cr0 /* and let's page NOW! */ 353 354#ifdef BDE_DEBUGGER 355/* 356 * Complete the adjustments for paging so that we can keep tracing through 357 * initi386() after the low (physical) addresses for the gdt and idt become 358 * invalid. 359 */ 360 call bdb_commit_paging 361#endif 362 363 pushl $begin /* jump to high virtualized address */ 364 ret 365 366/* now running relocated at KERNBASE where the system is linked to run */ 367begin: 368 /* set up bootstrap stack */ 369 movl proc0paddr,%eax /* location of in-kernel pages */ 370 leal UPAGES*PAGE_SIZE(%eax),%esp /* bootstrap stack end location */ 371 372 xorl %ebp,%ebp /* mark end of frames */ 373 374 movl IdlePTD,%esi 375 movl %esi,PCB_CR3(%eax) 376 377 testl $CPUID_PGE, R(cpu_feature) 378 jz 1f 379 movl %cr4, %eax 380 orl $CR4_PGE, %eax 381 movl %eax, %cr4 3821: 383 pushl physfree /* value of first for init386(first) */ 384 call init386 /* wire 386 chip for unix operation */ 385 386 /* 387 * Clean up the stack in a way that db_numargs() understands, so 388 * that backtraces in ddb don't underrun the stack. Traps for 389 * inaccessible memory are more fatal than usual this early. 390 */ 391 addl $4,%esp 392 393 call mi_startup /* autoconfiguration, mountroot etc */ 394 /* NOTREACHED */ 395 addl $0,%esp /* for db_numargs() again */ 396 397/* 398 * Signal trampoline, copied to top of user stack 399 */ 400NON_GPROF_ENTRY(sigcode) 401 call *SIGF_HANDLER(%esp) /* call signal handler */ 402 lea SIGF_UC(%esp),%eax /* get ucontext_t */ 403 pushl %eax 404 testl $PSL_VM,UC_EFLAGS(%eax) 405 jne 9f 406 movl UC_GS(%eax),%gs /* restore %gs */ 4079: 408 movl $SYS_sigreturn,%eax 409 pushl %eax /* junk to fake return addr. */ 410 int $0x80 /* enter kernel with args */ 4110: jmp 0b 412 413 ALIGN_TEXT 414osigcode: 415 call *SIGF_HANDLER(%esp) /* call signal handler */ 416 lea SIGF_SC(%esp),%eax /* get sigcontext */ 417 pushl %eax 418 testl $PSL_VM,SC_PS(%eax) 419 jne 9f 420 movl SC_GS(%eax),%gs /* restore %gs */ 4219: 422 movl $0x01d516,SC_TRAPNO(%eax) /* magic: 0ldSiG */ 423 movl $SYS_sigreturn,%eax 424 pushl %eax /* junk to fake return addr. */ 425 int $0x80 /* enter kernel with args */ 4260: jmp 0b 427 428 ALIGN_TEXT 429esigcode: 430 431 .data 432 .globl szsigcode, szosigcode 433szsigcode: 434 .long esigcode-sigcode 435szosigcode: 436 .long esigcode-osigcode 437 .text 438 439/********************************************************************** 440 * 441 * Recover the bootinfo passed to us from the boot program 442 * 443 */ 444recover_bootinfo: 445 /* 446 * This code is called in different ways depending on what loaded 447 * and started the kernel. This is used to detect how we get the 448 * arguments from the other code and what we do with them. 449 * 450 * Old disk boot blocks: 451 * (*btext)(howto, bootdev, cyloffset, esym); 452 * [return address == 0, and can NOT be returned to] 453 * [cyloffset was not supported by the FreeBSD boot code 454 * and always passed in as 0] 455 * [esym is also known as total in the boot code, and 456 * was never properly supported by the FreeBSD boot code] 457 * 458 * Old diskless netboot code: 459 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 460 * [return address != 0, and can NOT be returned to] 461 * If we are being booted by this code it will NOT work, 462 * so we are just going to halt if we find this case. 463 * 464 * New uniform boot code: 465 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 466 * [return address != 0, and can be returned to] 467 * 468 * There may seem to be a lot of wasted arguments in here, but 469 * that is so the newer boot code can still load very old kernels 470 * and old boot code can load new kernels. 471 */ 472 473 /* 474 * The old style disk boot blocks fake a frame on the stack and 475 * did an lret to get here. The frame on the stack has a return 476 * address of 0. 477 */ 478 cmpl $0,4(%ebp) 479 je olddiskboot 480 481 /* 482 * We have some form of return address, so this is either the 483 * old diskless netboot code, or the new uniform code. That can 484 * be detected by looking at the 5th argument, if it is 0 485 * we are being booted by the new uniform boot code. 486 */ 487 cmpl $0,24(%ebp) 488 je newboot 489 490 /* 491 * Seems we have been loaded by the old diskless boot code, we 492 * don't stand a chance of running as the diskless structure 493 * changed considerably between the two, so just halt. 494 */ 495 hlt 496 497 /* 498 * We have been loaded by the new uniform boot code. 499 * Let's check the bootinfo version, and if we do not understand 500 * it we return to the loader with a status of 1 to indicate this error 501 */ 502newboot: 503 movl 28(%ebp),%ebx /* &bootinfo.version */ 504 movl BI_VERSION(%ebx),%eax 505 cmpl $1,%eax /* We only understand version 1 */ 506 je 1f 507 movl $1,%eax /* Return status */ 508 leave 509 /* 510 * XXX this returns to our caller's caller (as is required) since 511 * we didn't set up a frame and our caller did. 512 */ 513 ret 514 5151: 516 /* 517 * If we have a kernelname copy it in 518 */ 519 movl BI_KERNELNAME(%ebx),%esi 520 cmpl $0,%esi 521 je 2f /* No kernelname */ 522 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 523 movl $R(kernelname),%edi 524 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 525 je 1f 526 movb $'/',(%edi) 527 incl %edi 528 decl %ecx 5291: 530 cld 531 rep 532 movsb 533 5342: 535 /* 536 * Determine the size of the boot loader's copy of the bootinfo 537 * struct. This is impossible to do properly because old versions 538 * of the struct don't contain a size field and there are 2 old 539 * versions with the same version number. 540 */ 541 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 542 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 543 je got_bi_size /* no, sizeless version */ 544 movl BI_SIZE(%ebx),%ecx 545got_bi_size: 546 547 /* 548 * Copy the common part of the bootinfo struct 549 */ 550 movl %ebx,%esi 551 movl $R(bootinfo),%edi 552 cmpl $BOOTINFO_SIZE,%ecx 553 jbe got_common_bi_size 554 movl $BOOTINFO_SIZE,%ecx 555got_common_bi_size: 556 cld 557 rep 558 movsb 559 560#ifdef NFS_ROOT 561#ifndef BOOTP_NFSV3 562 /* 563 * If we have a nfs_diskless structure copy it in 564 */ 565 movl BI_NFS_DISKLESS(%ebx),%esi 566 cmpl $0,%esi 567 je olddiskboot 568 movl $R(nfs_diskless),%edi 569 movl $NFSDISKLESS_SIZE,%ecx 570 cld 571 rep 572 movsb 573 movl $R(nfs_diskless_valid),%edi 574 movl $1,(%edi) 575#endif 576#endif 577 578 /* 579 * The old style disk boot. 580 * (*btext)(howto, bootdev, cyloffset, esym); 581 * Note that the newer boot code just falls into here to pick 582 * up howto and bootdev, cyloffset and esym are no longer used 583 */ 584olddiskboot: 585 movl 8(%ebp),%eax 586 movl %eax,R(boothowto) 587 movl 12(%ebp),%eax 588 movl %eax,R(bootdev) 589 590 ret 591 592 593/********************************************************************** 594 * 595 * Identify the CPU and initialize anything special about it 596 * 597 */ 598identify_cpu: 599 600 /* Try to toggle alignment check flag; does not exist on 386. */ 601 pushfl 602 popl %eax 603 movl %eax,%ecx 604 orl $PSL_AC,%eax 605 pushl %eax 606 popfl 607 pushfl 608 popl %eax 609 xorl %ecx,%eax 610 andl $PSL_AC,%eax 611 pushl %ecx 612 popfl 613 614 testl %eax,%eax 615 jnz try486 616 617 /* NexGen CPU does not have aligment check flag. */ 618 pushfl 619 movl $0x5555, %eax 620 xorl %edx, %edx 621 movl $2, %ecx 622 clc 623 divl %ecx 624 jz trynexgen 625 popfl 626 movl $CPU_386,R(cpu) 627 jmp 3f 628 629trynexgen: 630 popfl 631 movl $CPU_NX586,R(cpu) 632 movl $0x4778654e,R(cpu_vendor) # store vendor string 633 movl $0x72446e65,R(cpu_vendor+4) 634 movl $0x6e657669,R(cpu_vendor+8) 635 movl $0,R(cpu_vendor+12) 636 jmp 3f 637 638try486: /* Try to toggle identification flag; does not exist on early 486s. */ 639 pushfl 640 popl %eax 641 movl %eax,%ecx 642 xorl $PSL_ID,%eax 643 pushl %eax 644 popfl 645 pushfl 646 popl %eax 647 xorl %ecx,%eax 648 andl $PSL_ID,%eax 649 pushl %ecx 650 popfl 651 652 testl %eax,%eax 653 jnz trycpuid 654 movl $CPU_486,R(cpu) 655 656 /* 657 * Check Cyrix CPU 658 * Cyrix CPUs do not change the undefined flags following 659 * execution of the divide instruction which divides 5 by 2. 660 * 661 * Note: CPUID is enabled on M2, so it passes another way. 662 */ 663 pushfl 664 movl $0x5555, %eax 665 xorl %edx, %edx 666 movl $2, %ecx 667 clc 668 divl %ecx 669 jnc trycyrix 670 popfl 671 jmp 3f /* You may use Intel CPU. */ 672 673trycyrix: 674 popfl 675 /* 676 * IBM Bluelighting CPU also doesn't change the undefined flags. 677 * Because IBM doesn't disclose the information for Bluelighting 678 * CPU, we couldn't distinguish it from Cyrix's (including IBM 679 * brand of Cyrix CPUs). 680 */ 681 movl $0x69727943,R(cpu_vendor) # store vendor string 682 movl $0x736e4978,R(cpu_vendor+4) 683 movl $0x64616574,R(cpu_vendor+8) 684 jmp 3f 685 686trycpuid: /* Use the `cpuid' instruction. */ 687 xorl %eax,%eax 688 cpuid # cpuid 0 689 movl %eax,R(cpu_high) # highest capability 690 movl %ebx,R(cpu_vendor) # store vendor string 691 movl %edx,R(cpu_vendor+4) 692 movl %ecx,R(cpu_vendor+8) 693 movb $0,R(cpu_vendor+12) 694 695 movl $1,%eax 696 cpuid # cpuid 1 697 movl %eax,R(cpu_id) # store cpu_id 698 movl %edx,R(cpu_feature) # store cpu_feature 699 rorl $8,%eax # extract family type 700 andl $15,%eax 701 cmpl $5,%eax 702 jae 1f 703 704 /* less than Pentium; must be 486 */ 705 movl $CPU_486,R(cpu) 706 jmp 3f 7071: 708 /* a Pentium? */ 709 cmpl $5,%eax 710 jne 2f 711 movl $CPU_586,R(cpu) 712 jmp 3f 7132: 714 /* Greater than Pentium...call it a Pentium Pro */ 715 movl $CPU_686,R(cpu) 7163: 717 ret 718 719 720/********************************************************************** 721 * 722 * Create the first page directory and its page tables. 723 * 724 */ 725 726create_pagetables: 727 728/* Find end of kernel image (rounded up to a page boundary). */ 729 movl $R(_end),%esi 730 731/* Include symbols, if any. */ 732 movl R(bootinfo+BI_ESYMTAB),%edi 733 testl %edi,%edi 734 je over_symalloc 735 movl %edi,%esi 736 movl $KERNBASE,%edi 737 addl %edi,R(bootinfo+BI_SYMTAB) 738 addl %edi,R(bootinfo+BI_ESYMTAB) 739over_symalloc: 740 741/* If we are told where the end of the kernel space is, believe it. */ 742 movl R(bootinfo+BI_KERNEND),%edi 743 testl %edi,%edi 744 je no_kernend 745 movl %edi,%esi 746no_kernend: 747 748 addl $PAGE_MASK,%esi 749 andl $~PAGE_MASK,%esi 750 movl %esi,R(KERNend) /* save end of kernel */ 751 movl %esi,R(physfree) /* next free page is at end of kernel */ 752 753/* Allocate Kernel Page Tables */ 754 ALLOCPAGES(NKPT) 755 movl %esi,R(KPTphys) 756 757/* Allocate Page Table Directory */ 758 ALLOCPAGES(1) 759 movl %esi,R(IdlePTD) 760 761/* Allocate UPAGES */ 762 ALLOCPAGES(UPAGES) 763 movl %esi,R(p0upa) 764 addl $KERNBASE, %esi 765 movl %esi, R(proc0paddr) 766 767 ALLOCPAGES(1) /* vm86/bios stack */ 768 movl %esi,R(vm86phystk) 769 770 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 771 movl %esi,R(vm86pa) 772 addl $KERNBASE, %esi 773 movl %esi, R(vm86paddr) 774 775#ifdef SMP 776/* Allocate cpu0's private data page */ 777 ALLOCPAGES(1) 778 movl %esi,R(cpu0pp) 779 addl $KERNBASE, %esi 780 movl %esi, R(cpu0prvpage) /* relocated to KVM space */ 781 782/* Allocate SMP page table page */ 783 ALLOCPAGES(1) 784 movl %esi,R(SMPptpa) 785 addl $KERNBASE, %esi 786 movl %esi, R(SMPpt) /* relocated to KVM space */ 787#endif /* SMP */ 788 789/* Map read-only from zero to the end of the kernel text section */ 790 xorl %eax, %eax 791#ifdef BDE_DEBUGGER 792/* If the debugger is present, actually map everything read-write. */ 793 cmpl $0,R(_bdb_exists) 794 jne map_read_write 795#endif 796 xorl %edx,%edx 797 798#if !defined(SMP) 799 testl $CPUID_PGE, R(cpu_feature) 800 jz 2f 801 orl $PG_G,%edx 802#endif 803 8042: movl $R(etext),%ecx 805 addl $PAGE_MASK,%ecx 806 shrl $PAGE_SHIFT,%ecx 807 fillkptphys(%edx) 808 809/* Map read-write, data, bss and symbols */ 810 movl $R(etext),%eax 811 addl $PAGE_MASK, %eax 812 andl $~PAGE_MASK, %eax 813map_read_write: 814 movl $PG_RW,%edx 815#if !defined(SMP) 816 testl $CPUID_PGE, R(cpu_feature) 817 jz 1f 818 orl $PG_G,%edx 819#endif 820 8211: movl R(KERNend),%ecx 822 subl %eax,%ecx 823 shrl $PAGE_SHIFT,%ecx 824 fillkptphys(%edx) 825 826/* Map page directory. */ 827 movl R(IdlePTD), %eax 828 movl $1, %ecx 829 fillkptphys($PG_RW) 830 831/* Map proc0's UPAGES in the physical way ... */ 832 movl R(p0upa), %eax 833 movl $UPAGES, %ecx 834 fillkptphys($PG_RW) 835 836/* Map ISA hole */ 837 movl $ISA_HOLE_START, %eax 838 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 839 fillkptphys($PG_RW) 840 841/* Map space for the vm86 region */ 842 movl R(vm86phystk), %eax 843 movl $4, %ecx 844 fillkptphys($PG_RW) 845 846/* Map page 0 into the vm86 page table */ 847 movl $0, %eax 848 movl $0, %ebx 849 movl $1, %ecx 850 fillkpt(R(vm86pa), $PG_RW|PG_U) 851 852/* ...likewise for the ISA hole */ 853 movl $ISA_HOLE_START, %eax 854 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 855 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 856 fillkpt(R(vm86pa), $PG_RW|PG_U) 857 858#ifdef SMP 859/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 860 movl R(cpu0pp), %eax 861 movl $1, %ecx 862 fillkptphys($PG_RW) 863 864/* Map SMP page table page into global kmem FWIW */ 865 movl R(SMPptpa), %eax 866 movl $1, %ecx 867 fillkptphys($PG_RW) 868 869/* Map the private page into the SMP page table */ 870 movl R(cpu0pp), %eax 871 movl $0, %ebx /* pte offset = 0 */ 872 movl $1, %ecx /* one private page coming right up */ 873 fillkpt(R(SMPptpa), $PG_RW) 874 875/* ... and put the page table table in the pde. */ 876 movl R(SMPptpa), %eax 877 movl $MPPTDI, %ebx 878 movl $1, %ecx 879 fillkpt(R(IdlePTD), $PG_RW) 880 881/* Fakeup VA for the local apic to allow early traps. */ 882 ALLOCPAGES(1) 883 movl %esi, %eax 884 movl $(NPTEPG-1), %ebx /* pte offset = NTEPG-1 */ 885 movl $1, %ecx /* one private pt coming right up */ 886 fillkpt(R(SMPptpa), $PG_RW) 887#endif /* SMP */ 888 889/* install a pde for temporary double map of bottom of VA */ 890 movl R(KPTphys), %eax 891 xorl %ebx, %ebx 892 movl $NKPT, %ecx 893 fillkpt(R(IdlePTD), $PG_RW) 894 895/* install pde's for pt's */ 896 movl R(KPTphys), %eax 897 movl $KPTDI, %ebx 898 movl $NKPT, %ecx 899 fillkpt(R(IdlePTD), $PG_RW) 900 901/* install a pde recursively mapping page directory as a page table */ 902 movl R(IdlePTD), %eax 903 movl $PTDPTDI, %ebx 904 movl $1,%ecx 905 fillkpt(R(IdlePTD), $PG_RW) 906 907 ret 908 909#ifdef BDE_DEBUGGER 910bdb_prepare_paging: 911 cmpl $0,R(_bdb_exists) 912 je bdb_prepare_paging_exit 913 914 subl $6,%esp 915 916 /* 917 * Copy and convert debugger entries from the bootstrap gdt and idt 918 * to the kernel gdt and idt. Everything is still in low memory. 919 * Tracing continues to work after paging is enabled because the 920 * low memory addresses remain valid until everything is relocated. 921 * However, tracing through the setidt() that initializes the trace 922 * trap will crash. 923 */ 924 sgdt (%esp) 925 movl 2(%esp),%esi /* base address of bootstrap gdt */ 926 movl $R(_gdt),%edi 927 movl %edi,2(%esp) /* prepare to load kernel gdt */ 928 movl $8*18/4,%ecx 929 cld 930 rep /* copy gdt */ 931 movsl 932 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 933 movb $0x92,-8+5(%edi) 934 lgdt (%esp) 935 936 sidt (%esp) 937 movl 2(%esp),%esi /* base address of current idt */ 938 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 939 movw 8(%esi),%ax 940 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 941 movl 8+2(%esi),%eax 942 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 943 movl 24+4(%esi),%eax /* same for bpt descriptor */ 944 movw 24(%esi),%ax 945 movl %eax,R(bdb_bpt_ljmp+1) 946 movl 24+2(%esi),%eax 947 movw %ax,R(bdb_bpt_ljmp+5) 948 movl R(_idt),%edi 949 movl %edi,2(%esp) /* prepare to load kernel idt */ 950 movl $8*4/4,%ecx 951 cld 952 rep /* copy idt */ 953 movsl 954 lidt (%esp) 955 956 addl $6,%esp 957 958bdb_prepare_paging_exit: 959 ret 960 961/* Relocate debugger gdt entries and gdt and idt pointers. */ 962bdb_commit_paging: 963 cmpl $0,_bdb_exists 964 je bdb_commit_paging_exit 965 966 movl $gdt+8*9,%eax /* adjust slots 9-17 */ 967 movl $9,%ecx 968reloc_gdt: 969 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 970 addl $8,%eax /* now KERNBASE>>24 */ 971 loop reloc_gdt 972 973 subl $6,%esp 974 sgdt (%esp) 975 addl $KERNBASE,2(%esp) 976 lgdt (%esp) 977 sidt (%esp) 978 addl $KERNBASE,2(%esp) 979 lidt (%esp) 980 addl $6,%esp 981 982 int $3 983 984bdb_commit_paging_exit: 985 ret 986 987#endif /* BDE_DEBUGGER */ 988