locore.s revision 15471
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 * $Id: locore.s,v 1.67 1996/04/28 07:14:05 phk Exp $ 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 "apm.h" 47#include "opt_ddb.h" 48 49#include <sys/errno.h> 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/pte.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 .globl _PTmap,_PTD,_PTDpde 74 .set _PTmap,PTDPTDI << PDRSHIFT 75 .set _PTD,_PTmap + (PTDPTDI * NBPG) 76 .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 77 78/* 79 * Sysmap is the base address of the kernel page tables. 80 * It is a bogus interface for kgdb and isn't used by the kernel itself. 81 */ 82 .set _Sysmap,_PTmap + (KPTDI * NBPG) 83 84/* 85 * APTmap, APTD is the alternate recursive pagemap. 86 * It's used when modifying another process's page tables. 87 */ 88 .globl _APTmap,_APTD,_APTDpde 89 .set _APTmap,APTDPTDI << PDRSHIFT 90 .set _APTD,_APTmap + (APTDPTDI * NBPG) 91 .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 92 93/* 94 * Access to each processes kernel stack is via a region of 95 * per-process address space (at the beginning), immediately above 96 * the user process stack. 97 */ 98 .set _kstack,USRSTACK 99 .globl _kstack 100 101/* 102 * Globals 103 */ 104 .data 105 ALIGN_DATA /* just to be sure */ 106 107 .globl tmpstk 108 .space 0x2000 /* space for tmpstk - temporary stack */ 109tmpstk: 110 111 .globl _boothowto,_bootdev 112 113 .globl _cpu,_atdevbase,_cpu_vendor,_cpu_id,_bootinfo 114 .globl _cpu_high, _cpu_feature 115 116_cpu: .long 0 /* are we 386, 386sx, or 486 */ 117_cpu_id: .long 0 /* stepping ID */ 118_cpu_high: .long 0 /* highest arg to CPUID */ 119_cpu_feature: .long 0 /* features */ 120_cpu_vendor: .space 20 /* CPU origin code */ 121_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 122_atdevbase: .long 0 /* location of start of iomem in virtual */ 123 124_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 125physfree: .long 0 /* phys addr of next free page */ 126upa: .long 0 /* phys addr of proc0's UPAGES */ 127p0upt: .long 0 /* phys addr of proc0's UPAGES page table */ 128 129 .globl _IdlePTD 130_IdlePTD: .long 0 /* phys addr of kernel PTD */ 131 132_KPTphys: .long 0 /* phys addr of kernel page tables */ 133 134 .globl _proc0paddr 135_proc0paddr: .long 0 /* address of proc 0 address space */ 136 137#ifdef BDE_DEBUGGER 138 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 139_bdb_exists: .long 0 140#endif 141 142 143/********************************************************************** 144 * 145 * Some handy macros 146 * 147 */ 148 149#define R(foo) ((foo)-KERNBASE) 150 151#define ALLOCPAGES(foo) \ 152 movl R(physfree), %esi ; \ 153 movl $((foo)*NBPG), %eax ; \ 154 addl %esi, %eax ; \ 155 movl %eax, R(physfree) ; \ 156 movl %esi, %edi ; \ 157 movl $((foo)*NBPG),%ecx ; \ 158 xorl %eax,%eax ; \ 159 cld ; \ 160 rep ; \ 161 stosb 162 163/* 164 * fillkpt 165 * eax = (page frame address | control | status) == pte 166 * ebx = address of page table 167 * ecx = how many pages to map 168 */ 169#define fillkpt \ 1701: movl %eax,(%ebx) ; \ 171 addl $NBPG,%eax ; /* increment physical address */ \ 172 addl $4,%ebx ; /* next pte */ \ 173 loop 1b 174 175 .text 176/********************************************************************** 177 * 178 * This is where the bootblocks start us, set the ball rolling... 179 * 180 */ 181NON_GPROF_ENTRY(btext) 182 183#ifdef BDE_DEBUGGER 184#ifdef BIOS_STEALS_3K 185 cmpl $0x0375c339,0x95504 186#else 187 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 188#endif 189 jne 1f 190 movb $1,R(_bdb_exists) 1911: 192#endif 193 194/* Tell the bios to warmboot next time */ 195 movw $0x1234,0x472 196 197/* Set up a real frame in case the double return in newboot is executed. */ 198 pushl %ebp 199 movl %esp, %ebp 200 201/* Don't trust what the BIOS gives for eflags. */ 202 pushl $PSL_KERNEL 203 popfl 204 205/* 206 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 207 * to set %cs, %ds, %es and %ss. 208 */ 209 mov %ds, %ax 210 mov %ax, %fs 211 mov %ax, %gs 212 213 call recover_bootinfo 214 215/* Get onto a stack that we can trust. */ 216/* 217 * XXX this step is delayed in case recover_bootinfo needs to return via 218 * the old stack, but it need not be, since recover_bootinfo actually 219 * returns via the old frame. 220 */ 221 movl $R(tmpstk),%esp 222 223 call identify_cpu 224 225/* clear bss */ 226/* 227 * XXX this should be done a little earlier. (bde) 228 * 229 * XXX we don't check that there is memory for our bss or page tables 230 * before using it. (bde) 231 * 232 * XXX the boot program somewhat bogusly clears the bss. We still have 233 * to do it in case we were unzipped by kzipboot. Then the boot program 234 * only clears kzipboot's bss. 235 * 236 * XXX the gdt and idt are still somewhere in the boot program. We 237 * depend on the convention that the boot program is below 1MB and we 238 * are above 1MB to keep the gdt and idt away from the bss and page 239 * tables. The idT is only used if BDE_DEBUGGER is enabled. 240 */ 241 movl $R(_end),%ecx 242 movl $R(_edata),%edi 243 subl %edi,%ecx 244 xorl %eax,%eax 245 cld 246 rep 247 stosb 248 249#if NAPM > 0 250/* 251 * XXX it's not clear that APM can live in the current environonment. 252 * Only pc-relative addressing works. 253 */ 254 call _apm_setup 255#endif 256 257 call create_pagetables 258 259#ifdef BDE_DEBUGGER 260/* 261 * Adjust as much as possible for paging before enabling paging so that the 262 * adjustments can be traced. 263 */ 264 call bdb_prepare_paging 265#endif 266 267/* Now enable paging */ 268 movl R(_IdlePTD), %eax 269 movl %eax,%cr3 /* load ptd addr into mmu */ 270 movl %cr0,%eax /* get control word */ 271 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 272 movl %eax,%cr0 /* and let's page NOW! */ 273 274#ifdef BDE_DEBUGGER 275/* 276 * Complete the adjustments for paging so that we can keep tracing through 277 * initi386() after the low (physical) addresses for the gdt and idT become 278 * invalid. 279 */ 280 call bdb_commit_paging 281#endif 282 283 pushl $begin /* jump to high virtualized address */ 284 ret 285 286/* now running relocated at KERNBASE where the system is linked to run */ 287begin: 288 /* set up bootstrap stack */ 289 movl $_kstack+UPAGES*NBPG,%esp /* bootstrap stack end location */ 290 xorl %eax,%eax /* mark end of frames */ 291 movl %eax,%ebp 292 movl _proc0paddr,%eax 293 movl _IdlePTD, %esi 294 movl %esi,PCB_CR3(%eax) 295 296 movl physfree, %esi 297 pushl %esi /* value of first for init386(first) */ 298 call _init386 /* wire 386 chip for unix operation */ 299 popl %esi 300 301 .globl __ucodesel,__udatasel 302 303 pushl $0 /* unused */ 304 pushl __udatasel /* ss */ 305 pushl $0 /* esp - filled in by execve() */ 306 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 307 pushl __ucodesel /* cs */ 308 pushl $0 /* eip - filled in by execve() */ 309 subl $(12*4),%esp /* space for rest of registers */ 310 311 pushl %esp /* call main with frame pointer */ 312 call _main /* autoconfiguration, mountroot etc */ 313 314 addl $(13*4),%esp /* back to a frame we can return with */ 315 316 /* 317 * now we've run main() and determined what cpu-type we are, we can 318 * enable write protection and alignment checking on i486 cpus and 319 * above. 320 */ 321#if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU) 322 cmpl $CPUCLASS_386,_cpu_class 323 je 1f 324 movl %cr0,%eax /* get control word */ 325 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 326 movl %eax,%cr0 /* and do it */ 3271: 328#endif 329 /* 330 * on return from main(), we are process 1 331 * set up address space and stack so that we can 'return' to user mode 332 */ 333 movl __ucodesel,%eax 334 movl __udatasel,%ecx 335 336 movl %cx,%ds 337 movl %cx,%es 338 movl %ax,%fs /* double map cs to fs */ 339 movl %cx,%gs /* and ds to gs */ 340 iret /* goto user! */ 341 342#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 343 344/* 345 * Signal trampoline, copied to top of user stack 346 */ 347NON_GPROF_ENTRY(sigcode) 348 call SIGF_HANDLER(%esp) 349 lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 350 /* copy at 8(%esp)) */ 351 pushl %eax 352 pushl %eax /* junk to fake return address */ 353 movl $SYS_sigreturn,%eax /* sigreturn() */ 354 LCALL(0x7,0) /* enter kernel with args on stack */ 355 hlt /* never gets here */ 356 .align 2,0x90 /* long word text-align */ 357_esigcode: 358 359 .data 360 .globl _szsigcode 361_szsigcode: 362 .long _esigcode-_sigcode 363 .text 364 365/********************************************************************** 366 * 367 * Recover the bootinfo passed to us from the boot program 368 * 369 */ 370recover_bootinfo: 371 /* 372 * This code is called in different ways depending on what loaded 373 * and started the kernel. This is used to detect how we get the 374 * arguments from the other code and what we do with them. 375 * 376 * Old disk boot blocks: 377 * (*btext)(howto, bootdev, cyloffset, esym); 378 * [return address == 0, and can NOT be returned to] 379 * [cyloffset was not supported by the FreeBSD boot code 380 * and always passed in as 0] 381 * [esym is also known as total in the boot code, and 382 * was never properly supported by the FreeBSD boot code] 383 * 384 * Old diskless netboot code: 385 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 386 * [return address != 0, and can NOT be returned to] 387 * If we are being booted by this code it will NOT work, 388 * so we are just going to halt if we find this case. 389 * 390 * New uniform boot code: 391 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 392 * [return address != 0, and can be returned to] 393 * 394 * There may seem to be a lot of wasted arguments in here, but 395 * that is so the newer boot code can still load very old kernels 396 * and old boot code can load new kernels. 397 */ 398 399 /* 400 * The old style disk boot blocks fake a frame on the stack and 401 * did an lret to get here. The frame on the stack has a return 402 * address of 0. 403 */ 404 cmpl $0,4(%ebp) 405 je olddiskboot 406 407 /* 408 * We have some form of return address, so this is either the 409 * old diskless netboot code, or the new uniform code. That can 410 * be detected by looking at the 5th argument, if it is 0 411 * we are being booted by the new uniform boot code. 412 */ 413 cmpl $0,24(%ebp) 414 je newboot 415 416 /* 417 * Seems we have been loaded by the old diskless boot code, we 418 * don't stand a chance of running as the diskless structure 419 * changed considerably between the two, so just halt. 420 */ 421 hlt 422 423 /* 424 * We have been loaded by the new uniform boot code. 425 * Let's check the bootinfo version, and if we do not understand 426 * it we return to the loader with a status of 1 to indicate this error 427 */ 428newboot: 429 movl 28(%ebp),%ebx /* &bootinfo.version */ 430 movl BI_VERSION(%ebx),%eax 431 cmpl $1,%eax /* We only understand version 1 */ 432 je 1f 433 movl $1,%eax /* Return status */ 434 leave 435 /* 436 * XXX this returns to our caller's caller (as is required) since 437 * we didn't set up a frame and our caller did. 438 */ 439 ret 440 4411: 442 /* 443 * If we have a kernelname copy it in 444 */ 445 movl BI_KERNELNAME(%ebx),%esi 446 cmpl $0,%esi 447 je 2f /* No kernelname */ 448 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 449 lea _kernelname-KERNBASE,%edi 450 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 451 je 1f 452 movb $'/',(%edi) 453 incl %edi 454 decl %ecx 4551: 456 cld 457 rep 458 movsb 459 4602: 461 /* 462 * Determine the size of the boot loader's copy of the bootinfo 463 * struct. This is impossible to do properly because old versions 464 * of the struct don't contain a size field and there are 2 old 465 * versions with the same version number. 466 */ 467 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 468 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 469 je got_bi_size /* no, sizeless version */ 470 movl BI_SIZE(%ebx),%ecx 471got_bi_size: 472 473 /* 474 * Copy the common part of the bootinfo struct 475 */ 476 movl %ebx,%esi 477 movl $_bootinfo-KERNBASE,%edi 478 cmpl $BOOTINFO_SIZE,%ecx 479 jbe got_common_bi_size 480 movl $BOOTINFO_SIZE,%ecx 481got_common_bi_size: 482 cld 483 rep 484 movsb 485 486#ifdef NFS 487 /* 488 * If we have a nfs_diskless structure copy it in 489 */ 490 movl BI_NFS_DISKLESS(%ebx),%esi 491 cmpl $0,%esi 492 je olddiskboot 493 lea _nfs_diskless-KERNBASE,%edi 494 movl $NFSDISKLESS_SIZE,%ecx 495 cld 496 rep 497 movsb 498 lea _nfs_diskless_valid-KERNBASE,%edi 499 movl $1,(%edi) 500#endif 501 502 /* 503 * The old style disk boot. 504 * (*btext)(howto, bootdev, cyloffset, esym); 505 * Note that the newer boot code just falls into here to pick 506 * up howto and bootdev, cyloffset and esym are no longer used 507 */ 508olddiskboot: 509 movl 8(%ebp),%eax 510 movl %eax,_boothowto-KERNBASE 511 movl 12(%ebp),%eax 512 movl %eax,_bootdev-KERNBASE 513 514 ret 515 516 517/********************************************************************** 518 * 519 * Identify the CPU and initialize anything special about it 520 * 521 */ 522identify_cpu: 523 524 /* Try to toggle alignment check flag; does not exist on 386. */ 525 pushfl 526 popl %eax 527 movl %eax,%ecx 528 orl $PSL_AC,%eax 529 pushl %eax 530 popfl 531 pushfl 532 popl %eax 533 xorl %ecx,%eax 534 andl $PSL_AC,%eax 535 pushl %ecx 536 popfl 537 538 testl %eax,%eax 539 jnz 1f 540 movl $CPU_386,_cpu-KERNBASE 541 jmp 3f 542 5431: /* Try to toggle identification flag; does not exist on early 486s. */ 544 pushfl 545 popl %eax 546 movl %eax,%ecx 547 xorl $PSL_ID,%eax 548 pushl %eax 549 popfl 550 pushfl 551 popl %eax 552 xorl %ecx,%eax 553 andl $PSL_ID,%eax 554 pushl %ecx 555 popfl 556 557 testl %eax,%eax 558 jnz 1f 559 movl $CPU_486,_cpu-KERNBASE 560 561 /* check for Cyrix 486DLC -- based on check routine */ 562 /* documented in "Cx486SLC/e SMM Programmer's Guide" */ 563 xorw %dx,%dx 564 cmpw %dx,%dx # set flags to known state 565 pushfw 566 popw %cx # store flags in ecx 567 movw $0xffff,%ax 568 movw $0x0004,%bx 569 divw %bx 570 pushfw 571 popw %ax 572 andw $0x08d5,%ax # mask off important bits 573 andw $0x08d5,%cx 574 cmpw %ax,%cx 575 576 jnz 3f # if flags changed, Intel chip 577 578 movl $CPU_486DLC,_cpu-KERNBASE # set CPU value for Cyrix 579 movl $0x69727943,_cpu_vendor-KERNBASE # store vendor string 580 movw $0x0078,_cpu_vendor-KERNBASE+4 581 582#ifndef CYRIX_CACHE_WORKS 583 /* Disable caching of the ISA hole only. */ 584 invd 585 movb $CCR0,%al # Configuration Register index (CCR0) 586 outb %al,$0x22 587 inb $0x23,%al 588 orb $(CCR0_NC1|CCR0_BARB),%al 589 movb %al,%ah 590 movb $CCR0,%al 591 outb %al,$0x22 592 movb %ah,%al 593 outb %al,$0x23 594 invd 595#else /* CYRIX_CACHE_WORKS */ 596 /* Set cache parameters */ 597 invd # Start with guaranteed clean cache 598 movb $CCR0,%al # Configuration Register index (CCR0) 599 outb %al,$0x22 600 inb $0x23,%al 601 andb $~CCR0_NC0,%al 602#ifndef CYRIX_CACHE_REALLY_WORKS 603 orb $(CCR0_NC1|CCR0_BARB),%al 604#else /* CYRIX_CACHE_REALLY_WORKS */ 605 orb $CCR0_NC1,%al 606#endif /* !CYRIX_CACHE_REALLY_WORKS */ 607 movb %al,%ah 608 movb $CCR0,%al 609 outb %al,$0x22 610 movb %ah,%al 611 outb %al,$0x23 612 /* clear non-cacheable region 1 */ 613 movb $(NCR1+2),%al 614 outb %al,$0x22 615 movb $NCR_SIZE_0K,%al 616 outb %al,$0x23 617 /* clear non-cacheable region 2 */ 618 movb $(NCR2+2),%al 619 outb %al,$0x22 620 movb $NCR_SIZE_0K,%al 621 outb %al,$0x23 622 /* clear non-cacheable region 3 */ 623 movb $(NCR3+2),%al 624 outb %al,$0x22 625 movb $NCR_SIZE_0K,%al 626 outb %al,$0x23 627 /* clear non-cacheable region 4 */ 628 movb $(NCR4+2),%al 629 outb %al,$0x22 630 movb $NCR_SIZE_0K,%al 631 outb %al,$0x23 632 /* enable caching in CR0 */ 633 movl %cr0,%eax 634 andl $~(CR0_CD|CR0_NW),%eax 635 movl %eax,%cr0 636 invd 637#endif /* !CYRIX_CACHE_WORKS */ 638 jmp 3f 639 6401: /* Use the `cpuid' instruction. */ 641 xorl %eax,%eax 642 .byte 0x0f,0xa2 # cpuid 0 643 movl %eax,_cpu_high-KERNBASE # highest capability 644 movl %ebx,_cpu_vendor-KERNBASE # store vendor string 645 movl %edx,_cpu_vendor+4-KERNBASE 646 movl %ecx,_cpu_vendor+8-KERNBASE 647 movb $0,_cpu_vendor+12-KERNBASE 648 649 movl $1,%eax 650 .byte 0x0f,0xa2 # cpuid 1 651 movl %eax,_cpu_id-KERNBASE # store cpu_id 652 movl %edx,_cpu_feature-KERNBASE # store cpu_feature 653 rorl $8,%eax # extract family type 654 andl $15,%eax 655 cmpl $5,%eax 656 jae 1f 657 658 /* less than Pentium; must be 486 */ 659 movl $CPU_486,_cpu-KERNBASE 660 jmp 3f 6611: 662 /* a Pentium? */ 663 cmpl $5,%eax 664 jne 2f 665 movl $CPU_586,_cpu-KERNBASE 666 jmp 3f 6672: 668 /* Greater than Pentium...call it a Pentium Pro */ 669 movl $CPU_686,_cpu-KERNBASE 6703: 671 ret 672 673 674/********************************************************************** 675 * 676 * Create the first page directory and its page tables. 677 * 678 */ 679 680create_pagetables: 681 682/* Find end of kernel image (rounded up to a page boundary). */ 683 movl $R(_end),%esi 684 685/* include symbols in "kernel image" if they are loaded and useful */ 686#ifdef DDB 687 movl R(_bootinfo+BI_ESYMTAB),%edi 688 testl %edi,%edi 689 je over_symalloc 690 movl %edi,%esi 691 movl $KERNBASE,%edi 692 addl %edi,R(_bootinfo+BI_SYMTAB) 693 addl %edi,R(_bootinfo+BI_ESYMTAB) 694over_symalloc: 695#endif 696 697 addl $NBPG-1,%esi 698 andl $~(NBPG-1),%esi 699 movl %esi,R(_KERNend) /* save end of kernel */ 700 movl %esi,R(physfree) /* next free page is at end of kernel */ 701 702/* Allocate Kernel Page Tables */ 703 ALLOCPAGES(NKPT) 704 movl %esi,R(_KPTphys) 705 706/* Allocate Page Table Directory */ 707 ALLOCPAGES(1) 708 movl %esi,R(_IdlePTD) 709 710/* Allocate UPAGES */ 711 ALLOCPAGES(UPAGES) 712 movl %esi,R(upa) 713 addl $KERNBASE, %esi 714 movl %esi, R(_proc0paddr) 715 716/* Allocate proc0's page table for the UPAGES. */ 717 ALLOCPAGES(1) 718 movl %esi,R(p0upt) 719 720/* Map read-only from zero to the end of the kernel text section */ 721 movl R(_KPTphys), %esi 722 movl $R(_etext),%ecx 723 addl $NBPG-1,%ecx 724 shrl $PGSHIFT,%ecx 725 movl $PG_V|PG_KR,%eax 726 movl %esi, %ebx 727#ifdef BDE_DEBUGGER 728/* If the debugger is present, actually map everything read-write. */ 729 cmpl $0,R(_bdb_exists) 730 jne map_read_write 731#endif 732 fillkpt 733 734/* Map read-write, data, bss and symbols */ 735map_read_write: 736 andl $PG_FRAME,%eax 737 movl R(_KERNend),%ecx 738 subl %eax,%ecx 739 shrl $PGSHIFT,%ecx 740 orl $PG_V|PG_KW,%eax 741 fillkpt 742 743/* Map page directory. */ 744 movl R(_IdlePTD), %eax 745 movl $1, %ecx 746 movl %eax, %ebx 747 shrl $PGSHIFT-2, %ebx 748 addl R(_KPTphys), %ebx 749 orl $PG_V|PG_KW, %eax 750 fillkpt 751 752/* Map proc0's page table for the UPAGES the physical way. */ 753 movl R(p0upt), %eax 754 movl $1, %ecx 755 movl %eax, %ebx 756 shrl $PGSHIFT-2, %ebx 757 addl R(_KPTphys), %ebx 758 orl $PG_V|PG_KW, %eax 759 fillkpt 760 761/* Map proc0s UPAGES the physical way */ 762 movl R(upa), %eax 763 movl $UPAGES, %ecx 764 movl %eax, %ebx 765 shrl $PGSHIFT-2, %ebx 766 addl R(_KPTphys), %ebx 767 orl $PG_V|PG_KW, %eax 768 fillkpt 769 770/* ... and in the special page table for this purpose. */ 771 movl R(upa), %eax 772 movl $UPAGES, %ecx 773 orl $PG_V|PG_KW, %eax 774 movl R(p0upt), %ebx 775 addl $(KSTKPTEOFF * PTESIZE), %ebx 776 fillkpt 777 778/* and put the page table in the pde. */ 779 movl R(p0upt), %eax 780 movl R(_IdlePTD), %esi 781 orl $PG_V|PG_KW,%eax 782 movl %eax,KSTKPTDI*PDESIZE(%esi) 783 784/* Map ISA hole */ 785#define ISA_HOLE_START 0xa0000 786#define ISA_HOLE_LENGTH (0x100000-ISA_HOLE_START) 787 movl $ISA_HOLE_LENGTH>>PGSHIFT, %ecx 788 movl $ISA_HOLE_START, %eax 789 movl %eax, %ebx 790/* XXX 2 is magic for log2(PTESIZE). */ 791 shrl $PGSHIFT-2, %ebx 792 addl R(_KPTphys), %ebx 793/* XXX could load %eax directly with $ISA_HOLE_START|PG_V|PG_KW_PG_N. */ 794 orl $PG_V|PG_KW|PG_N, %eax 795 fillkpt 796/* XXX could load %eax directly with $ISA_HOLE_START+KERNBASE. */ 797 movl $ISA_HOLE_START, %eax 798 addl $KERNBASE, %eax 799 movl %eax, R(_atdevbase) 800 801/* install a pde for temporary double map of bottom of VA */ 802 movl R(_IdlePTD), %esi 803 movl R(_KPTphys), %eax 804 orl $PG_V|PG_KW, %eax 805 movl %eax, (%esi) 806 807/* install pde's for pt's */ 808 movl R(_IdlePTD), %esi 809 movl R(_KPTphys), %eax 810 orl $PG_V|PG_KW, %eax 811 movl $(NKPT), %ecx 812 lea (KPTDI*PDESIZE)(%esi), %ebx 813 fillkpt 814 815/* install a pde recursively mapping page directory as a page table */ 816 movl R(_IdlePTD), %esi 817 movl %esi,%eax 818 orl $PG_V|PG_KW,%eax 819 movl %eax,PTDPTDI*PDESIZE(%esi) 820 821 ret 822 823#ifdef BDE_DEBUGGER 824bdb_prepare_paging: 825 cmpl $0,R(_bdb_exists) 826 je bdb_prepare_paging_exit 827 828 subl $6,%esp 829 830 /* 831 * Copy and convert debugger entries from the bootstrap gdt and idt 832 * to the kernel gdt and idt. Everything is still in low memory. 833 * Tracing continues to work after paging is enabled because the 834 * low memory addresses remain valid until everything is relocated. 835 * However, tracing through the setidt() that initializes the trace 836 * trap will crash. 837 */ 838 sgdt (%esp) 839 movl 2(%esp),%esi /* base address of bootstrap gdt */ 840 movl $R(_gdt),%edi 841 movl %edi,2(%esp) /* prepare to load kernel gdt */ 842 movl $8*18/4,%ecx 843 cld 844 rep /* copy gdt */ 845 movsl 846 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 847 movb $0x92,-8+5(%edi) 848 lgdt (%esp) 849 850 sidt (%esp) 851 movl 2(%esp),%esi /* base address of current idt */ 852 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 853 movw 8(%esi),%ax 854 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 855 movl 8+2(%esi),%eax 856 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 857 movl 24+4(%esi),%eax /* same for bpt descriptor */ 858 movw 24(%esi),%ax 859 movl %eax,R(bdb_bpt_ljmp+1) 860 movl 24+2(%esi),%eax 861 movw %ax,R(bdb_bpt_ljmp+5) 862 movl $R(_idt),%edi 863 movl %edi,2(%esp) /* prepare to load kernel idt */ 864 movl $8*4/4,%ecx 865 cld 866 rep /* copy idt */ 867 movsl 868 lidt (%esp) 869 870 addl $6,%esp 871 872bdb_prepare_paging_exit: 873 ret 874 875/* Relocate debugger gdt entries and gdt and idt pointers. */ 876bdb_commit_paging: 877 cmpl $0,_bdb_exists 878 je bdb_commit_paging_exit 879 880 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 881 movl $9,%ecx 882reloc_gdt: 883 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 884 addl $8,%eax /* now KERNBASE>>24 */ 885 loop reloc_gdt 886 887 subl $6,%esp 888 sgdt (%esp) 889 addl $KERNBASE,2(%esp) 890 lgdt (%esp) 891 sidt (%esp) 892 addl $KERNBASE,2(%esp) 893 lidt (%esp) 894 addl $6,%esp 895 896 int $3 897 898bdb_commit_paging_exit: 899 ret 900 901#endif /* BDE_DEBUGGER */ 902