locore.s revision 82957
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 82957 2001-09-04 11:05:33Z 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_nfsroot.h" 48 49#include <sys/syscall.h> 50#include <sys/reboot.h> 51 52#include <machine/asmacros.h> 53#include <machine/cputypes.h> 54#include <machine/psl.h> 55#include <machine/pmap.h> 56#include <machine/specialreg.h> 57 58#include "assym.s" 59 60#ifdef __AOUT__ 61#define etext _etext 62#define edata _edata 63#define end _end 64#endif 65 66/* 67 * XXX 68 * 69 * Note: This version greatly munged to avoid various assembler errors 70 * that may be fixed in newer versions of gas. Perhaps newer versions 71 * will have more pleasant appearance. 72 */ 73 74/* 75 * PTmap is recursive pagemap at top of virtual address space. 76 * Within PTmap, the page directory can be found (third indirection). 77 * 78 * NOTE: PTDpde, PTmap, and PTD are being defined as address symbols. 79 * In C you access them directly, and not with a '*'. Storage is not being 80 * allocated. They will magically address the correct locations in KVM 81 * which C will treat as normal variables of the type they are defined in 82 * machine/pmap.h, i.e. PTDpde = XX ; to set a PDE entry, NOT *PTDpde = XX; 83 */ 84 .globl PTmap,PTD,PTDpde 85 .set PTmap,(PTDPTDI << PDRSHIFT) 86 .set PTD,PTmap + (PTDPTDI * PAGE_SIZE) 87 .set PTDpde,PTD + (PTDPTDI * PDESIZE) 88 89/* 90 * APTmap, APTD is the alternate recursive pagemap. 91 * It's used when modifying another process's page tables. 92 * See the note above. It is true here as well. 93 */ 94 .globl APTmap,APTD,APTDpde 95 .set APTmap,APTDPTDI << PDRSHIFT 96 .set APTD,APTmap + (APTDPTDI * PAGE_SIZE) 97 .set APTDpde,PTD + (APTDPTDI * PDESIZE) 98 99#ifdef SMP 100/* 101 * Define layout of per-cpu address space. 102 * This is "constructed" in locore.s on the BSP and in mp_machdep.c 103 * for each AP. DO NOT REORDER THESE WITHOUT UPDATING THE REST! 104 */ 105 .globl SMP_prvspace, lapic 106 .set SMP_prvspace,(MPPTDI << PDRSHIFT) 107 .set lapic,SMP_prvspace + (NPTEPG-1) * PAGE_SIZE 108#endif /* SMP */ 109 110/* 111 * Compiled KERNBASE location 112 */ 113 .globl kernbase 114 .set kernbase,KERNBASE 115 116/* 117 * Globals 118 */ 119 .data 120 ALIGN_DATA /* just to be sure */ 121 122 .globl HIDENAME(tmpstk) 123 .space 0x2000 /* space for tmpstk - temporary stack */ 124HIDENAME(tmpstk): 125 126 .globl bootinfo 127bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 128 129KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 130physfree: .long 0 /* phys addr of next free page */ 131 132#ifdef SMP 133 .globl cpu0prvpage 134cpu0pp: .long 0 /* phys addr cpu0 private pg */ 135cpu0prvpage: .long 0 /* relocated version */ 136 137 .globl SMPpt 138SMPptpa: .long 0 /* phys addr SMP page table */ 139SMPpt: .long 0 /* relocated version */ 140#endif /* SMP */ 141 142 .globl IdlePTD 143IdlePTD: .long 0 /* phys addr of kernel PTD */ 144 145#ifdef SMP 146 .globl KPTphys 147#endif 148KPTphys: .long 0 /* phys addr of kernel page tables */ 149 150 .globl proc0paddr 151proc0paddr: .long 0 /* address of proc 0 address space */ 152p0upa: .long 0 /* phys addr of proc0's UPAGES */ 153 154vm86phystk: .long 0 /* PA of vm86/bios stack */ 155 156 .globl vm86paddr, vm86pa 157vm86paddr: .long 0 /* address of vm86 region */ 158vm86pa: .long 0 /* phys addr of vm86 region */ 159 160#ifdef BDE_DEBUGGER 161 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 162_bdb_exists: .long 0 163#endif 164 165#ifdef PC98 166 .globl pc98_system_parameter 167pc98_system_parameter: 168 .space 0x240 169#endif 170 171/********************************************************************** 172 * 173 * Some handy macros 174 * 175 */ 176 177#define R(foo) ((foo)-KERNBASE) 178 179#define ALLOCPAGES(foo) \ 180 movl R(physfree), %esi ; \ 181 movl $((foo)*PAGE_SIZE), %eax ; \ 182 addl %esi, %eax ; \ 183 movl %eax, R(physfree) ; \ 184 movl %esi, %edi ; \ 185 movl $((foo)*PAGE_SIZE),%ecx ; \ 186 xorl %eax,%eax ; \ 187 cld ; \ 188 rep ; \ 189 stosb 190 191/* 192 * fillkpt 193 * eax = page frame address 194 * ebx = index into page table 195 * ecx = how many pages to map 196 * base = base address of page dir/table 197 * prot = protection bits 198 */ 199#define fillkpt(base, prot) \ 200 shll $2,%ebx ; \ 201 addl base,%ebx ; \ 202 orl $PG_V,%eax ; \ 203 orl prot,%eax ; \ 2041: movl %eax,(%ebx) ; \ 205 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 206 addl $4,%ebx ; /* next pte */ \ 207 loop 1b 208 209/* 210 * fillkptphys(prot) 211 * eax = physical address 212 * ecx = how many pages to map 213 * prot = protection bits 214 */ 215#define fillkptphys(prot) \ 216 movl %eax, %ebx ; \ 217 shrl $PAGE_SHIFT, %ebx ; \ 218 fillkpt(R(KPTphys), prot) 219 220 .text 221/********************************************************************** 222 * 223 * This is where the bootblocks start us, set the ball rolling... 224 * 225 */ 226NON_GPROF_ENTRY(btext) 227 228#ifdef PC98 229 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 230 movl $0xa1400,%esi 231 movl $R(pc98_system_parameter),%edi 232 movl $0x0240,%ecx 233 cld 234 rep 235 movsb 236#else /* IBM-PC */ 237#ifdef BDE_DEBUGGER 238#ifdef BIOS_STEALS_3K 239 cmpl $0x0375c339,0x95504 240#else 241 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 242#endif 243 jne 1f 244 movb $1,R(_bdb_exists) 2451: 246#endif 247/* Tell the bios to warmboot next time */ 248 movw $0x1234,0x472 249#endif /* PC98 */ 250 251/* Set up a real frame in case the double return in newboot is executed. */ 252 pushl %ebp 253 movl %esp, %ebp 254 255/* Don't trust what the BIOS gives for eflags. */ 256 pushl $PSL_KERNEL 257 popfl 258 259/* 260 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 261 * to set %cs, %ds, %es and %ss. 262 */ 263 mov %ds, %ax 264 mov %ax, %fs 265 mov %ax, %gs 266 267 call recover_bootinfo 268 269/* Get onto a stack that we can trust. */ 270/* 271 * XXX this step is delayed in case recover_bootinfo needs to return via 272 * the old stack, but it need not be, since recover_bootinfo actually 273 * returns via the old frame. 274 */ 275 movl $R(HIDENAME(tmpstk)),%esp 276 277#ifdef PC98 278 /* pc98_machine_type & M_EPSON_PC98 */ 279 testb $0x02,R(pc98_system_parameter)+220 280 jz 3f 281 /* epson_machine_id <= 0x0b */ 282 cmpb $0x0b,R(pc98_system_parameter)+224 283 ja 3f 284 285 /* count up memory */ 286 movl $0x100000,%eax /* next, talley remaining memory */ 287 movl $0xFFF-0x100,%ecx 2881: movl 0(%eax),%ebx /* save location to check */ 289 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 290 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 291 jne 2f 292 movl %ebx,0(%eax) /* restore memory */ 293 addl $PAGE_SIZE,%eax 294 loop 1b 2952: subl $0x100000,%eax 296 shrl $17,%eax 297 movb %al,R(pc98_system_parameter)+1 2983: 299 300 movw R(pc98_system_parameter+0x86),%ax 301 movw %ax,R(cpu_id) 302#endif 303 304 call identify_cpu 305 306/* clear bss */ 307/* 308 * XXX this should be done a little earlier. 309 * 310 * XXX we don't check that there is memory for our bss and page tables 311 * before using it. 312 * 313 * XXX the boot program somewhat bogusly clears the bss. We still have 314 * to do it in case we were unzipped by kzipboot. Then the boot program 315 * only clears kzipboot's bss. 316 * 317 * XXX the gdt and idt are still somewhere in the boot program. We 318 * depend on the convention that the boot program is below 1MB and we 319 * are above 1MB to keep the gdt and idt away from the bss and page 320 * tables. The idt is only used if BDE_DEBUGGER is enabled. 321 */ 322 movl $R(end),%ecx 323 movl $R(edata),%edi 324 subl %edi,%ecx 325 xorl %eax,%eax 326 cld 327 rep 328 stosb 329 330 call create_pagetables 331 332/* 333 * If the CPU has support for VME, turn it on. 334 */ 335 testl $CPUID_VME, R(cpu_feature) 336 jz 1f 337 movl %cr4, %eax 338 orl $CR4_VME, %eax 339 movl %eax, %cr4 3401: 341 342#ifdef BDE_DEBUGGER 343/* 344 * Adjust as much as possible for paging before enabling paging so that the 345 * adjustments can be traced. 346 */ 347 call bdb_prepare_paging 348#endif 349 350/* Now enable paging */ 351 movl R(IdlePTD), %eax 352 movl %eax,%cr3 /* load ptd addr into mmu */ 353 movl %cr0,%eax /* get control word */ 354 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 355 movl %eax,%cr0 /* and let's page NOW! */ 356 357#ifdef BDE_DEBUGGER 358/* 359 * Complete the adjustments for paging so that we can keep tracing through 360 * initi386() after the low (physical) addresses for the gdt and idt become 361 * invalid. 362 */ 363 call bdb_commit_paging 364#endif 365 366 pushl $begin /* jump to high virtualized address */ 367 ret 368 369/* now running relocated at KERNBASE where the system is linked to run */ 370begin: 371 /* set up bootstrap stack */ 372 movl proc0paddr,%eax /* location of in-kernel pages */ 373 leal UPAGES*PAGE_SIZE(%eax),%esp /* bootstrap stack end location */ 374 375 xorl %ebp,%ebp /* mark end of frames */ 376 377 movl IdlePTD,%esi 378 movl %esi,PCB_CR3(%eax) 379 380 testl $CPUID_PGE, R(cpu_feature) 381 jz 1f 382 movl %cr4, %eax 383 orl $CR4_PGE, %eax 384 movl %eax, %cr4 3851: 386 pushl physfree /* value of first for init386(first) */ 387 call init386 /* wire 386 chip for unix operation */ 388 389 /* 390 * Clean up the stack in a way that db_numargs() understands, so 391 * that backtraces in ddb don't underrun the stack. Traps for 392 * inaccessible memory are more fatal than usual this early. 393 */ 394 addl $4,%esp 395 396 call mi_startup /* autoconfiguration, mountroot etc */ 397 /* NOTREACHED */ 398 addl $0,%esp /* for db_numargs() again */ 399 400/* 401 * Signal trampoline, copied to top of user stack 402 */ 403NON_GPROF_ENTRY(sigcode) 404 call *SIGF_HANDLER(%esp) /* call signal handler */ 405 lea SIGF_UC(%esp),%eax /* get ucontext_t */ 406 pushl %eax 407 testl $PSL_VM,UC_EFLAGS(%eax) 408 jne 9f 409 movl UC_GS(%eax),%gs /* restore %gs */ 4109: 411 movl $SYS_sigreturn,%eax 412 pushl %eax /* junk to fake return addr. */ 413 int $0x80 /* enter kernel with args */ 4140: jmp 0b 415 416 ALIGN_TEXT 417osigcode: 418 call *SIGF_HANDLER(%esp) /* call signal handler */ 419 lea SIGF_SC(%esp),%eax /* get sigcontext */ 420 pushl %eax 421 testl $PSL_VM,SC_PS(%eax) 422 jne 9f 423 movl SC_GS(%eax),%gs /* restore %gs */ 4249: 425 movl $0x01d516,SC_TRAPNO(%eax) /* magic: 0ldSiG */ 426 movl $SYS_sigreturn,%eax 427 pushl %eax /* junk to fake return addr. */ 428 int $0x80 /* enter kernel with args */ 4290: jmp 0b 430 431 ALIGN_TEXT 432esigcode: 433 434 .data 435 .globl szsigcode, szosigcode 436szsigcode: 437 .long esigcode-sigcode 438szosigcode: 439 .long esigcode-osigcode 440 .text 441 442/********************************************************************** 443 * 444 * Recover the bootinfo passed to us from the boot program 445 * 446 */ 447recover_bootinfo: 448 /* 449 * This code is called in different ways depending on what loaded 450 * and started the kernel. This is used to detect how we get the 451 * arguments from the other code and what we do with them. 452 * 453 * Old disk boot blocks: 454 * (*btext)(howto, bootdev, cyloffset, esym); 455 * [return address == 0, and can NOT be returned to] 456 * [cyloffset was not supported by the FreeBSD boot code 457 * and always passed in as 0] 458 * [esym is also known as total in the boot code, and 459 * was never properly supported by the FreeBSD boot code] 460 * 461 * Old diskless netboot code: 462 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 463 * [return address != 0, and can NOT be returned to] 464 * If we are being booted by this code it will NOT work, 465 * so we are just going to halt if we find this case. 466 * 467 * New uniform boot code: 468 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 469 * [return address != 0, and can be returned to] 470 * 471 * There may seem to be a lot of wasted arguments in here, but 472 * that is so the newer boot code can still load very old kernels 473 * and old boot code can load new kernels. 474 */ 475 476 /* 477 * The old style disk boot blocks fake a frame on the stack and 478 * did an lret to get here. The frame on the stack has a return 479 * address of 0. 480 */ 481 cmpl $0,4(%ebp) 482 je olddiskboot 483 484 /* 485 * We have some form of return address, so this is either the 486 * old diskless netboot code, or the new uniform code. That can 487 * be detected by looking at the 5th argument, if it is 0 488 * we are being booted by the new uniform boot code. 489 */ 490 cmpl $0,24(%ebp) 491 je newboot 492 493 /* 494 * Seems we have been loaded by the old diskless boot code, we 495 * don't stand a chance of running as the diskless structure 496 * changed considerably between the two, so just halt. 497 */ 498 hlt 499 500 /* 501 * We have been loaded by the new uniform boot code. 502 * Let's check the bootinfo version, and if we do not understand 503 * it we return to the loader with a status of 1 to indicate this error 504 */ 505newboot: 506 movl 28(%ebp),%ebx /* &bootinfo.version */ 507 movl BI_VERSION(%ebx),%eax 508 cmpl $1,%eax /* We only understand version 1 */ 509 je 1f 510 movl $1,%eax /* Return status */ 511 leave 512 /* 513 * XXX this returns to our caller's caller (as is required) since 514 * we didn't set up a frame and our caller did. 515 */ 516 ret 517 5181: 519 /* 520 * If we have a kernelname copy it in 521 */ 522 movl BI_KERNELNAME(%ebx),%esi 523 cmpl $0,%esi 524 je 2f /* No kernelname */ 525 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 526 movl $R(kernelname),%edi 527 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 528 je 1f 529 movb $'/',(%edi) 530 incl %edi 531 decl %ecx 5321: 533 cld 534 rep 535 movsb 536 5372: 538 /* 539 * Determine the size of the boot loader's copy of the bootinfo 540 * struct. This is impossible to do properly because old versions 541 * of the struct don't contain a size field and there are 2 old 542 * versions with the same version number. 543 */ 544 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 545 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 546 je got_bi_size /* no, sizeless version */ 547 movl BI_SIZE(%ebx),%ecx 548got_bi_size: 549 550 /* 551 * Copy the common part of the bootinfo struct 552 */ 553 movl %ebx,%esi 554 movl $R(bootinfo),%edi 555 cmpl $BOOTINFO_SIZE,%ecx 556 jbe got_common_bi_size 557 movl $BOOTINFO_SIZE,%ecx 558got_common_bi_size: 559 cld 560 rep 561 movsb 562 563#ifdef NFS_ROOT 564#ifndef BOOTP_NFSV3 565 /* 566 * If we have a nfs_diskless structure copy it in 567 */ 568 movl BI_NFS_DISKLESS(%ebx),%esi 569 cmpl $0,%esi 570 je olddiskboot 571 movl $R(nfs_diskless),%edi 572 movl $NFSDISKLESS_SIZE,%ecx 573 cld 574 rep 575 movsb 576 movl $R(nfs_diskless_valid),%edi 577 movl $1,(%edi) 578#endif 579#endif 580 581 /* 582 * The old style disk boot. 583 * (*btext)(howto, bootdev, cyloffset, esym); 584 * Note that the newer boot code just falls into here to pick 585 * up howto and bootdev, cyloffset and esym are no longer used 586 */ 587olddiskboot: 588 movl 8(%ebp),%eax 589 movl %eax,R(boothowto) 590 movl 12(%ebp),%eax 591 movl %eax,R(bootdev) 592 593 ret 594 595 596/********************************************************************** 597 * 598 * Identify the CPU and initialize anything special about it 599 * 600 */ 601identify_cpu: 602 603 /* Try to toggle alignment check flag; does not exist on 386. */ 604 pushfl 605 popl %eax 606 movl %eax,%ecx 607 orl $PSL_AC,%eax 608 pushl %eax 609 popfl 610 pushfl 611 popl %eax 612 xorl %ecx,%eax 613 andl $PSL_AC,%eax 614 pushl %ecx 615 popfl 616 617 testl %eax,%eax 618 jnz try486 619 620 /* NexGen CPU does not have aligment check flag. */ 621 pushfl 622 movl $0x5555, %eax 623 xorl %edx, %edx 624 movl $2, %ecx 625 clc 626 divl %ecx 627 jz trynexgen 628 popfl 629 movl $CPU_386,R(cpu) 630 jmp 3f 631 632trynexgen: 633 popfl 634 movl $CPU_NX586,R(cpu) 635 movl $0x4778654e,R(cpu_vendor) # store vendor string 636 movl $0x72446e65,R(cpu_vendor+4) 637 movl $0x6e657669,R(cpu_vendor+8) 638 movl $0,R(cpu_vendor+12) 639 jmp 3f 640 641try486: /* Try to toggle identification flag; does not exist on early 486s. */ 642 pushfl 643 popl %eax 644 movl %eax,%ecx 645 xorl $PSL_ID,%eax 646 pushl %eax 647 popfl 648 pushfl 649 popl %eax 650 xorl %ecx,%eax 651 andl $PSL_ID,%eax 652 pushl %ecx 653 popfl 654 655 testl %eax,%eax 656 jnz trycpuid 657 movl $CPU_486,R(cpu) 658 659 /* 660 * Check Cyrix CPU 661 * Cyrix CPUs do not change the undefined flags following 662 * execution of the divide instruction which divides 5 by 2. 663 * 664 * Note: CPUID is enabled on M2, so it passes another way. 665 */ 666 pushfl 667 movl $0x5555, %eax 668 xorl %edx, %edx 669 movl $2, %ecx 670 clc 671 divl %ecx 672 jnc trycyrix 673 popfl 674 jmp 3f /* You may use Intel CPU. */ 675 676trycyrix: 677 popfl 678 /* 679 * IBM Bluelighting CPU also doesn't change the undefined flags. 680 * Because IBM doesn't disclose the information for Bluelighting 681 * CPU, we couldn't distinguish it from Cyrix's (including IBM 682 * brand of Cyrix CPUs). 683 */ 684 movl $0x69727943,R(cpu_vendor) # store vendor string 685 movl $0x736e4978,R(cpu_vendor+4) 686 movl $0x64616574,R(cpu_vendor+8) 687 jmp 3f 688 689trycpuid: /* Use the `cpuid' instruction. */ 690 xorl %eax,%eax 691 cpuid # cpuid 0 692 movl %eax,R(cpu_high) # highest capability 693 movl %ebx,R(cpu_vendor) # store vendor string 694 movl %edx,R(cpu_vendor+4) 695 movl %ecx,R(cpu_vendor+8) 696 movb $0,R(cpu_vendor+12) 697 698 movl $1,%eax 699 cpuid # cpuid 1 700 movl %eax,R(cpu_id) # store cpu_id 701 movl %edx,R(cpu_feature) # store cpu_feature 702 rorl $8,%eax # extract family type 703 andl $15,%eax 704 cmpl $5,%eax 705 jae 1f 706 707 /* less than Pentium; must be 486 */ 708 movl $CPU_486,R(cpu) 709 jmp 3f 7101: 711 /* a Pentium? */ 712 cmpl $5,%eax 713 jne 2f 714 movl $CPU_586,R(cpu) 715 jmp 3f 7162: 717 /* Greater than Pentium...call it a Pentium Pro */ 718 movl $CPU_686,R(cpu) 7193: 720 ret 721 722 723/********************************************************************** 724 * 725 * Create the first page directory and its page tables. 726 * 727 */ 728 729create_pagetables: 730 731/* Find end of kernel image (rounded up to a page boundary). */ 732 movl $R(_end),%esi 733 734/* Include symbols, if any. */ 735 movl R(bootinfo+BI_ESYMTAB),%edi 736 testl %edi,%edi 737 je over_symalloc 738 movl %edi,%esi 739 movl $KERNBASE,%edi 740 addl %edi,R(bootinfo+BI_SYMTAB) 741 addl %edi,R(bootinfo+BI_ESYMTAB) 742over_symalloc: 743 744/* If we are told where the end of the kernel space is, believe it. */ 745 movl R(bootinfo+BI_KERNEND),%edi 746 testl %edi,%edi 747 je no_kernend 748 movl %edi,%esi 749no_kernend: 750 751 addl $PAGE_MASK,%esi 752 andl $~PAGE_MASK,%esi 753 movl %esi,R(KERNend) /* save end of kernel */ 754 movl %esi,R(physfree) /* next free page is at end of kernel */ 755 756/* Allocate Kernel Page Tables */ 757 ALLOCPAGES(NKPT) 758 movl %esi,R(KPTphys) 759 760/* Allocate Page Table Directory */ 761 ALLOCPAGES(1) 762 movl %esi,R(IdlePTD) 763 764/* Allocate UPAGES */ 765 ALLOCPAGES(UPAGES) 766 movl %esi,R(p0upa) 767 addl $KERNBASE, %esi 768 movl %esi, R(proc0paddr) 769 770 ALLOCPAGES(1) /* vm86/bios stack */ 771 movl %esi,R(vm86phystk) 772 773 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 774 movl %esi,R(vm86pa) 775 addl $KERNBASE, %esi 776 movl %esi, R(vm86paddr) 777 778#ifdef SMP 779/* Allocate cpu0's private data page */ 780 ALLOCPAGES(1) 781 movl %esi,R(cpu0pp) 782 addl $KERNBASE, %esi 783 movl %esi, R(cpu0prvpage) /* relocated to KVM space */ 784 785/* Allocate SMP page table page */ 786 ALLOCPAGES(1) 787 movl %esi,R(SMPptpa) 788 addl $KERNBASE, %esi 789 movl %esi, R(SMPpt) /* relocated to KVM space */ 790#endif /* SMP */ 791 792/* Map read-only from zero to the end of the kernel text section */ 793 xorl %eax, %eax 794#ifdef BDE_DEBUGGER 795/* If the debugger is present, actually map everything read-write. */ 796 cmpl $0,R(_bdb_exists) 797 jne map_read_write 798#endif 799 xorl %edx,%edx 800 801#if !defined(SMP) 802 testl $CPUID_PGE, R(cpu_feature) 803 jz 2f 804 orl $PG_G,%edx 805#endif 806 8072: movl $R(etext),%ecx 808 addl $PAGE_MASK,%ecx 809 shrl $PAGE_SHIFT,%ecx 810 fillkptphys(%edx) 811 812/* Map read-write, data, bss and symbols */ 813 movl $R(etext),%eax 814 addl $PAGE_MASK, %eax 815 andl $~PAGE_MASK, %eax 816map_read_write: 817 movl $PG_RW,%edx 818#if !defined(SMP) 819 testl $CPUID_PGE, R(cpu_feature) 820 jz 1f 821 orl $PG_G,%edx 822#endif 823 8241: movl R(KERNend),%ecx 825 subl %eax,%ecx 826 shrl $PAGE_SHIFT,%ecx 827 fillkptphys(%edx) 828 829/* Map page directory. */ 830 movl R(IdlePTD), %eax 831 movl $1, %ecx 832 fillkptphys($PG_RW) 833 834/* Map proc0's UPAGES in the physical way ... */ 835 movl R(p0upa), %eax 836 movl $UPAGES, %ecx 837 fillkptphys($PG_RW) 838 839/* Map ISA hole */ 840 movl $ISA_HOLE_START, %eax 841 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 842 fillkptphys($PG_RW) 843 844/* Map space for the vm86 region */ 845 movl R(vm86phystk), %eax 846 movl $4, %ecx 847 fillkptphys($PG_RW) 848 849/* Map page 0 into the vm86 page table */ 850 movl $0, %eax 851 movl $0, %ebx 852 movl $1, %ecx 853 fillkpt(R(vm86pa), $PG_RW|PG_U) 854 855/* ...likewise for the ISA hole */ 856 movl $ISA_HOLE_START, %eax 857 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 858 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 859 fillkpt(R(vm86pa), $PG_RW|PG_U) 860 861#ifdef SMP 862/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 863 movl R(cpu0pp), %eax 864 movl $1, %ecx 865 fillkptphys($PG_RW) 866 867/* Map SMP page table page into global kmem FWIW */ 868 movl R(SMPptpa), %eax 869 movl $1, %ecx 870 fillkptphys($PG_RW) 871 872/* Map the private page into the SMP page table */ 873 movl R(cpu0pp), %eax 874 movl $0, %ebx /* pte offset = 0 */ 875 movl $1, %ecx /* one private page coming right up */ 876 fillkpt(R(SMPptpa), $PG_RW) 877 878/* ... and put the page table table in the pde. */ 879 movl R(SMPptpa), %eax 880 movl $MPPTDI, %ebx 881 movl $1, %ecx 882 fillkpt(R(IdlePTD), $PG_RW) 883 884/* Fakeup VA for the local apic to allow early traps. */ 885 ALLOCPAGES(1) 886 movl %esi, %eax 887 movl $(NPTEPG-1), %ebx /* pte offset = NTEPG-1 */ 888 movl $1, %ecx /* one private pt coming right up */ 889 fillkpt(R(SMPptpa), $PG_RW) 890#endif /* SMP */ 891 892/* install a pde for temporary double map of bottom of VA */ 893 movl R(KPTphys), %eax 894 xorl %ebx, %ebx 895 movl $NKPT, %ecx 896 fillkpt(R(IdlePTD), $PG_RW) 897 898/* install pde's for pt's */ 899 movl R(KPTphys), %eax 900 movl $KPTDI, %ebx 901 movl $NKPT, %ecx 902 fillkpt(R(IdlePTD), $PG_RW) 903 904/* install a pde recursively mapping page directory as a page table */ 905 movl R(IdlePTD), %eax 906 movl $PTDPTDI, %ebx 907 movl $1,%ecx 908 fillkpt(R(IdlePTD), $PG_RW) 909 910 ret 911 912#ifdef BDE_DEBUGGER 913bdb_prepare_paging: 914 cmpl $0,R(_bdb_exists) 915 je bdb_prepare_paging_exit 916 917 subl $6,%esp 918 919 /* 920 * Copy and convert debugger entries from the bootstrap gdt and idt 921 * to the kernel gdt and idt. Everything is still in low memory. 922 * Tracing continues to work after paging is enabled because the 923 * low memory addresses remain valid until everything is relocated. 924 * However, tracing through the setidt() that initializes the trace 925 * trap will crash. 926 */ 927 sgdt (%esp) 928 movl 2(%esp),%esi /* base address of bootstrap gdt */ 929 movl $R(_gdt),%edi 930 movl %edi,2(%esp) /* prepare to load kernel gdt */ 931 movl $8*18/4,%ecx 932 cld 933 rep /* copy gdt */ 934 movsl 935 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 936 movb $0x92,-8+5(%edi) 937 lgdt (%esp) 938 939 sidt (%esp) 940 movl 2(%esp),%esi /* base address of current idt */ 941 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 942 movw 8(%esi),%ax 943 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 944 movl 8+2(%esi),%eax 945 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 946 movl 24+4(%esi),%eax /* same for bpt descriptor */ 947 movw 24(%esi),%ax 948 movl %eax,R(bdb_bpt_ljmp+1) 949 movl 24+2(%esi),%eax 950 movw %ax,R(bdb_bpt_ljmp+5) 951 movl R(_idt),%edi 952 movl %edi,2(%esp) /* prepare to load kernel idt */ 953 movl $8*4/4,%ecx 954 cld 955 rep /* copy idt */ 956 movsl 957 lidt (%esp) 958 959 addl $6,%esp 960 961bdb_prepare_paging_exit: 962 ret 963 964/* Relocate debugger gdt entries and gdt and idt pointers. */ 965bdb_commit_paging: 966 cmpl $0,_bdb_exists 967 je bdb_commit_paging_exit 968 969 movl $gdt+8*9,%eax /* adjust slots 9-17 */ 970 movl $9,%ecx 971reloc_gdt: 972 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 973 addl $8,%eax /* now KERNBASE>>24 */ 974 loop reloc_gdt 975 976 subl $6,%esp 977 sgdt (%esp) 978 addl $KERNBASE,2(%esp) 979 lgdt (%esp) 980 sidt (%esp) 981 addl $KERNBASE,2(%esp) 982 lidt (%esp) 983 addl $6,%esp 984 985 int $3 986 987bdb_commit_paging_exit: 988 ret 989 990#endif /* BDE_DEBUGGER */ 991