locore.s revision 15694
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 1.70 1996/05/02 22:24:55 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/pmap.h> 57#include <machine/specialreg.h> 58 59#include "assym.s" 60 61/* 62 * XXX 63 * 64 * Note: This version greatly munged to avoid various assembler errors 65 * that may be fixed in newer versions of gas. Perhaps newer versions 66 * will have more pleasant appearance. 67 */ 68 69/* 70 * PTmap is recursive pagemap at top of virtual address space. 71 * Within PTmap, the page directory can be found (third indirection). 72 */ 73 .globl _PTmap,_PTD,_PTDpde 74 .set _PTmap,(PTDPTDI << PDRSHIFT) 75 .set _PTD,_PTmap + (PTDPTDI * PAGE_SIZE) 76 .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 77 78/* 79 * APTmap, APTD is the alternate recursive pagemap. 80 * It's used when modifying another process's page tables. 81 */ 82 .globl _APTmap,_APTD,_APTDpde 83 .set _APTmap,APTDPTDI << PDRSHIFT 84 .set _APTD,_APTmap + (APTDPTDI * PAGE_SIZE) 85 .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 86 87/* 88 * Access to each processes kernel stack is via a region of 89 * per-process address space (at the beginning), immediately above 90 * the user process stack. 91 */ 92 .set _kstack,USRSTACK 93 .globl _kstack 94 95/* 96 * Globals 97 */ 98 .data 99 ALIGN_DATA /* just to be sure */ 100 101 .globl tmpstk 102 .space 0x2000 /* space for tmpstk - temporary stack */ 103tmpstk: 104 105 .globl _boothowto,_bootdev 106 107 .globl _cpu,_cpu_vendor,_cpu_id,_bootinfo 108 .globl _cpu_high, _cpu_feature 109 110_cpu: .long 0 /* are we 386, 386sx, or 486 */ 111_cpu_id: .long 0 /* stepping ID */ 112_cpu_high: .long 0 /* highest arg to CPUID */ 113_cpu_feature: .long 0 /* features */ 114_cpu_vendor: .space 20 /* CPU origin code */ 115_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 116 117_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 118physfree: .long 0 /* phys addr of next free page */ 119upa: .long 0 /* phys addr of proc0's UPAGES */ 120p0upt: .long 0 /* phys addr of proc0's UPAGES page table */ 121 122 .globl _IdlePTD 123_IdlePTD: .long 0 /* phys addr of kernel PTD */ 124 125_KPTphys: .long 0 /* phys addr of kernel page tables */ 126 127 .globl _proc0paddr 128_proc0paddr: .long 0 /* address of proc 0 address space */ 129 130#ifdef BDE_DEBUGGER 131 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 132_bdb_exists: .long 0 133#endif 134 135 136/********************************************************************** 137 * 138 * Some handy macros 139 * 140 */ 141 142#define R(foo) ((foo)-KERNBASE) 143 144#define ALLOCPAGES(foo) \ 145 movl R(physfree), %esi ; \ 146 movl $((foo)*PAGE_SIZE), %eax ; \ 147 addl %esi, %eax ; \ 148 movl %eax, R(physfree) ; \ 149 movl %esi, %edi ; \ 150 movl $((foo)*PAGE_SIZE),%ecx ; \ 151 xorl %eax,%eax ; \ 152 cld ; \ 153 rep ; \ 154 stosb 155 156/* 157 * fillkpt 158 * eax = page frame address 159 * ebx = index into page table 160 * ecx = how many pages to map 161 * base = base address of page dir/table 162 * prot = protection bits 163 */ 164#define fillkpt(base, prot) \ 165 shll $2, %ebx ; \ 166 addl base, %ebx ; \ 167 orl $PG_V+prot, %eax ; \ 1681: movl %eax,(%ebx) ; \ 169 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 170 addl $4,%ebx ; /* next pte */ \ 171 loop 1b 172 173/* 174 * fillkptphys(prot) 175 * eax = physical address 176 * ecx = how many pages to map 177 * prot = protection bits 178 */ 179#define fillkptphys(prot) \ 180 movl %eax, %ebx ; \ 181 shrl $PAGE_SHIFT, %ebx ; \ 182 fillkpt(R(_KPTphys), prot) 183 184 .text 185/********************************************************************** 186 * 187 * This is where the bootblocks start us, set the ball rolling... 188 * 189 */ 190NON_GPROF_ENTRY(btext) 191 192#ifdef BDE_DEBUGGER 193#ifdef BIOS_STEALS_3K 194 cmpl $0x0375c339,0x95504 195#else 196 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 197#endif 198 jne 1f 199 movb $1,R(_bdb_exists) 2001: 201#endif 202 203/* Tell the bios to warmboot next time */ 204 movw $0x1234,0x472 205 206/* Set up a real frame in case the double return in newboot is executed. */ 207 pushl %ebp 208 movl %esp, %ebp 209 210/* Don't trust what the BIOS gives for eflags. */ 211 pushl $PSL_KERNEL 212 popfl 213 214/* 215 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 216 * to set %cs, %ds, %es and %ss. 217 */ 218 mov %ds, %ax 219 mov %ax, %fs 220 mov %ax, %gs 221 222 call recover_bootinfo 223 224/* Get onto a stack that we can trust. */ 225/* 226 * XXX this step is delayed in case recover_bootinfo needs to return via 227 * the old stack, but it need not be, since recover_bootinfo actually 228 * returns via the old frame. 229 */ 230 movl $R(tmpstk),%esp 231 232 call identify_cpu 233 234/* clear bss */ 235/* 236 * XXX this should be done a little earlier. (bde) 237 * 238 * XXX we don't check that there is memory for our bss or page tables 239 * before using it. (bde) 240 * 241 * XXX the boot program somewhat bogusly clears the bss. We still have 242 * to do it in case we were unzipped by kzipboot. Then the boot program 243 * only clears kzipboot's bss. 244 * 245 * XXX the gdt and idt are still somewhere in the boot program. We 246 * depend on the convention that the boot program is below 1MB and we 247 * are above 1MB to keep the gdt and idt away from the bss and page 248 * tables. The idT is only used if BDE_DEBUGGER is enabled. 249 */ 250 movl $R(_end),%ecx 251 movl $R(_edata),%edi 252 subl %edi,%ecx 253 xorl %eax,%eax 254 cld 255 rep 256 stosb 257 258#if NAPM > 0 259/* 260 * XXX it's not clear that APM can live in the current environonment. 261 * Only pc-relative addressing works. 262 */ 263 call _apm_setup 264#endif 265 266 call create_pagetables 267 268#ifdef BDE_DEBUGGER 269/* 270 * Adjust as much as possible for paging before enabling paging so that the 271 * adjustments can be traced. 272 */ 273 call bdb_prepare_paging 274#endif 275 276/* Now enable paging */ 277 movl R(_IdlePTD), %eax 278 movl %eax,%cr3 /* load ptd addr into mmu */ 279 movl %cr0,%eax /* get control word */ 280 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 281 movl %eax,%cr0 /* and let's page NOW! */ 282 283#ifdef BDE_DEBUGGER 284/* 285 * Complete the adjustments for paging so that we can keep tracing through 286 * initi386() after the low (physical) addresses for the gdt and idT become 287 * invalid. 288 */ 289 call bdb_commit_paging 290#endif 291 292 pushl $begin /* jump to high virtualized address */ 293 ret 294 295/* now running relocated at KERNBASE where the system is linked to run */ 296begin: 297 /* set up bootstrap stack */ 298 movl $_kstack+UPAGES*PAGE_SIZE,%esp /* bootstrap stack end location */ 299 xorl %eax,%eax /* mark end of frames */ 300 movl %eax,%ebp 301 movl _proc0paddr,%eax 302 movl _IdlePTD, %esi 303 movl %esi,PCB_CR3(%eax) 304 305 movl physfree, %esi 306 pushl %esi /* value of first for init386(first) */ 307 call _init386 /* wire 386 chip for unix operation */ 308 popl %esi 309 310 .globl __ucodesel,__udatasel 311 312 pushl $0 /* unused */ 313 pushl __udatasel /* ss */ 314 pushl $0 /* esp - filled in by execve() */ 315 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 316 pushl __ucodesel /* cs */ 317 pushl $0 /* eip - filled in by execve() */ 318 subl $(12*4),%esp /* space for rest of registers */ 319 320 pushl %esp /* call main with frame pointer */ 321 call _main /* autoconfiguration, mountroot etc */ 322 323 addl $(13*4),%esp /* back to a frame we can return with */ 324 325 /* 326 * now we've run main() and determined what cpu-type we are, we can 327 * enable write protection and alignment checking on i486 cpus and 328 * above. 329 */ 330#if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU) 331 cmpl $CPUCLASS_386,_cpu_class 332 je 1f 333 movl %cr0,%eax /* get control word */ 334 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 335 movl %eax,%cr0 /* and do it */ 3361: 337#endif 338 /* 339 * on return from main(), we are process 1 340 * set up address space and stack so that we can 'return' to user mode 341 */ 342 movl __ucodesel,%eax 343 movl __udatasel,%ecx 344 345 movl %cx,%ds 346 movl %cx,%es 347 movl %ax,%fs /* double map cs to fs */ 348 movl %cx,%gs /* and ds to gs */ 349 iret /* goto user! */ 350 351#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 352 353/* 354 * Signal trampoline, copied to top of user stack 355 */ 356NON_GPROF_ENTRY(sigcode) 357 call SIGF_HANDLER(%esp) 358 lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 359 /* copy at 8(%esp)) */ 360 pushl %eax 361 pushl %eax /* junk to fake return address */ 362 movl $SYS_sigreturn,%eax /* sigreturn() */ 363 LCALL(0x7,0) /* enter kernel with args on stack */ 364 hlt /* never gets here */ 365 .align 2,0x90 /* long word text-align */ 366_esigcode: 367 368 .data 369 .globl _szsigcode 370_szsigcode: 371 .long _esigcode-_sigcode 372 .text 373 374/********************************************************************** 375 * 376 * Recover the bootinfo passed to us from the boot program 377 * 378 */ 379recover_bootinfo: 380 /* 381 * This code is called in different ways depending on what loaded 382 * and started the kernel. This is used to detect how we get the 383 * arguments from the other code and what we do with them. 384 * 385 * Old disk boot blocks: 386 * (*btext)(howto, bootdev, cyloffset, esym); 387 * [return address == 0, and can NOT be returned to] 388 * [cyloffset was not supported by the FreeBSD boot code 389 * and always passed in as 0] 390 * [esym is also known as total in the boot code, and 391 * was never properly supported by the FreeBSD boot code] 392 * 393 * Old diskless netboot code: 394 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 395 * [return address != 0, and can NOT be returned to] 396 * If we are being booted by this code it will NOT work, 397 * so we are just going to halt if we find this case. 398 * 399 * New uniform boot code: 400 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 401 * [return address != 0, and can be returned to] 402 * 403 * There may seem to be a lot of wasted arguments in here, but 404 * that is so the newer boot code can still load very old kernels 405 * and old boot code can load new kernels. 406 */ 407 408 /* 409 * The old style disk boot blocks fake a frame on the stack and 410 * did an lret to get here. The frame on the stack has a return 411 * address of 0. 412 */ 413 cmpl $0,4(%ebp) 414 je olddiskboot 415 416 /* 417 * We have some form of return address, so this is either the 418 * old diskless netboot code, or the new uniform code. That can 419 * be detected by looking at the 5th argument, if it is 0 420 * we are being booted by the new uniform boot code. 421 */ 422 cmpl $0,24(%ebp) 423 je newboot 424 425 /* 426 * Seems we have been loaded by the old diskless boot code, we 427 * don't stand a chance of running as the diskless structure 428 * changed considerably between the two, so just halt. 429 */ 430 hlt 431 432 /* 433 * We have been loaded by the new uniform boot code. 434 * Let's check the bootinfo version, and if we do not understand 435 * it we return to the loader with a status of 1 to indicate this error 436 */ 437newboot: 438 movl 28(%ebp),%ebx /* &bootinfo.version */ 439 movl BI_VERSION(%ebx),%eax 440 cmpl $1,%eax /* We only understand version 1 */ 441 je 1f 442 movl $1,%eax /* Return status */ 443 leave 444 /* 445 * XXX this returns to our caller's caller (as is required) since 446 * we didn't set up a frame and our caller did. 447 */ 448 ret 449 4501: 451 /* 452 * If we have a kernelname copy it in 453 */ 454 movl BI_KERNELNAME(%ebx),%esi 455 cmpl $0,%esi 456 je 2f /* No kernelname */ 457 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 458 lea _kernelname-KERNBASE,%edi 459 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 460 je 1f 461 movb $'/',(%edi) 462 incl %edi 463 decl %ecx 4641: 465 cld 466 rep 467 movsb 468 4692: 470 /* 471 * Determine the size of the boot loader's copy of the bootinfo 472 * struct. This is impossible to do properly because old versions 473 * of the struct don't contain a size field and there are 2 old 474 * versions with the same version number. 475 */ 476 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 477 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 478 je got_bi_size /* no, sizeless version */ 479 movl BI_SIZE(%ebx),%ecx 480got_bi_size: 481 482 /* 483 * Copy the common part of the bootinfo struct 484 */ 485 movl %ebx,%esi 486 movl $_bootinfo-KERNBASE,%edi 487 cmpl $BOOTINFO_SIZE,%ecx 488 jbe got_common_bi_size 489 movl $BOOTINFO_SIZE,%ecx 490got_common_bi_size: 491 cld 492 rep 493 movsb 494 495#ifdef NFS 496 /* 497 * If we have a nfs_diskless structure copy it in 498 */ 499 movl BI_NFS_DISKLESS(%ebx),%esi 500 cmpl $0,%esi 501 je olddiskboot 502 lea _nfs_diskless-KERNBASE,%edi 503 movl $NFSDISKLESS_SIZE,%ecx 504 cld 505 rep 506 movsb 507 lea _nfs_diskless_valid-KERNBASE,%edi 508 movl $1,(%edi) 509#endif 510 511 /* 512 * The old style disk boot. 513 * (*btext)(howto, bootdev, cyloffset, esym); 514 * Note that the newer boot code just falls into here to pick 515 * up howto and bootdev, cyloffset and esym are no longer used 516 */ 517olddiskboot: 518 movl 8(%ebp),%eax 519 movl %eax,_boothowto-KERNBASE 520 movl 12(%ebp),%eax 521 movl %eax,_bootdev-KERNBASE 522 523 ret 524 525 526/********************************************************************** 527 * 528 * Identify the CPU and initialize anything special about it 529 * 530 */ 531identify_cpu: 532 533 /* Try to toggle alignment check flag; does not exist on 386. */ 534 pushfl 535 popl %eax 536 movl %eax,%ecx 537 orl $PSL_AC,%eax 538 pushl %eax 539 popfl 540 pushfl 541 popl %eax 542 xorl %ecx,%eax 543 andl $PSL_AC,%eax 544 pushl %ecx 545 popfl 546 547 testl %eax,%eax 548 jnz 1f 549 movl $CPU_386,_cpu-KERNBASE 550 jmp 3f 551 5521: /* Try to toggle identification flag; does not exist on early 486s. */ 553 pushfl 554 popl %eax 555 movl %eax,%ecx 556 xorl $PSL_ID,%eax 557 pushl %eax 558 popfl 559 pushfl 560 popl %eax 561 xorl %ecx,%eax 562 andl $PSL_ID,%eax 563 pushl %ecx 564 popfl 565 566 testl %eax,%eax 567 jnz 1f 568 movl $CPU_486,_cpu-KERNBASE 569 570 /* check for Cyrix 486DLC -- based on check routine */ 571 /* documented in "Cx486SLC/e SMM Programmer's Guide" */ 572 xorw %dx,%dx 573 cmpw %dx,%dx # set flags to known state 574 pushfw 575 popw %cx # store flags in ecx 576 movw $0xffff,%ax 577 movw $0x0004,%bx 578 divw %bx 579 pushfw 580 popw %ax 581 andw $0x08d5,%ax # mask off important bits 582 andw $0x08d5,%cx 583 cmpw %ax,%cx 584 585 jnz 3f # if flags changed, Intel chip 586 587 movl $CPU_486DLC,_cpu-KERNBASE # set CPU value for Cyrix 588 movl $0x69727943,_cpu_vendor-KERNBASE # store vendor string 589 movw $0x0078,_cpu_vendor-KERNBASE+4 590 591#ifndef CYRIX_CACHE_WORKS 592 /* Disable caching of the ISA hole only. */ 593 invd 594 movb $CCR0,%al # Configuration Register index (CCR0) 595 outb %al,$0x22 596 inb $0x23,%al 597 orb $(CCR0_NC1|CCR0_BARB),%al 598 movb %al,%ah 599 movb $CCR0,%al 600 outb %al,$0x22 601 movb %ah,%al 602 outb %al,$0x23 603 invd 604#else /* CYRIX_CACHE_WORKS */ 605 /* Set cache parameters */ 606 invd # Start with guaranteed clean cache 607 movb $CCR0,%al # Configuration Register index (CCR0) 608 outb %al,$0x22 609 inb $0x23,%al 610 andb $~CCR0_NC0,%al 611#ifndef CYRIX_CACHE_REALLY_WORKS 612 orb $(CCR0_NC1|CCR0_BARB),%al 613#else /* CYRIX_CACHE_REALLY_WORKS */ 614 orb $CCR0_NC1,%al 615#endif /* !CYRIX_CACHE_REALLY_WORKS */ 616 movb %al,%ah 617 movb $CCR0,%al 618 outb %al,$0x22 619 movb %ah,%al 620 outb %al,$0x23 621 /* clear non-cacheable region 1 */ 622 movb $(NCR1+2),%al 623 outb %al,$0x22 624 movb $NCR_SIZE_0K,%al 625 outb %al,$0x23 626 /* clear non-cacheable region 2 */ 627 movb $(NCR2+2),%al 628 outb %al,$0x22 629 movb $NCR_SIZE_0K,%al 630 outb %al,$0x23 631 /* clear non-cacheable region 3 */ 632 movb $(NCR3+2),%al 633 outb %al,$0x22 634 movb $NCR_SIZE_0K,%al 635 outb %al,$0x23 636 /* clear non-cacheable region 4 */ 637 movb $(NCR4+2),%al 638 outb %al,$0x22 639 movb $NCR_SIZE_0K,%al 640 outb %al,$0x23 641 /* enable caching in CR0 */ 642 movl %cr0,%eax 643 andl $~(CR0_CD|CR0_NW),%eax 644 movl %eax,%cr0 645 invd 646#endif /* !CYRIX_CACHE_WORKS */ 647 jmp 3f 648 6491: /* Use the `cpuid' instruction. */ 650 xorl %eax,%eax 651 .byte 0x0f,0xa2 # cpuid 0 652 movl %eax,_cpu_high-KERNBASE # highest capability 653 movl %ebx,_cpu_vendor-KERNBASE # store vendor string 654 movl %edx,_cpu_vendor+4-KERNBASE 655 movl %ecx,_cpu_vendor+8-KERNBASE 656 movb $0,_cpu_vendor+12-KERNBASE 657 658 movl $1,%eax 659 .byte 0x0f,0xa2 # cpuid 1 660 movl %eax,_cpu_id-KERNBASE # store cpu_id 661 movl %edx,_cpu_feature-KERNBASE # store cpu_feature 662 rorl $8,%eax # extract family type 663 andl $15,%eax 664 cmpl $5,%eax 665 jae 1f 666 667 /* less than Pentium; must be 486 */ 668 movl $CPU_486,_cpu-KERNBASE 669 jmp 3f 6701: 671 /* a Pentium? */ 672 cmpl $5,%eax 673 jne 2f 674 movl $CPU_586,_cpu-KERNBASE 675 jmp 3f 6762: 677 /* Greater than Pentium...call it a Pentium Pro */ 678 movl $CPU_686,_cpu-KERNBASE 6793: 680 ret 681 682 683/********************************************************************** 684 * 685 * Create the first page directory and its page tables. 686 * 687 */ 688 689create_pagetables: 690 691/* Find end of kernel image (rounded up to a page boundary). */ 692 movl $R(_end),%esi 693 694/* include symbols in "kernel image" if they are loaded and useful */ 695#ifdef DDB 696 movl R(_bootinfo+BI_ESYMTAB),%edi 697 testl %edi,%edi 698 je over_symalloc 699 movl %edi,%esi 700 movl $KERNBASE,%edi 701 addl %edi,R(_bootinfo+BI_SYMTAB) 702 addl %edi,R(_bootinfo+BI_ESYMTAB) 703over_symalloc: 704#endif 705 706 addl $PAGE_MASK,%esi 707 andl $~PAGE_MASK,%esi 708 movl %esi,R(_KERNend) /* save end of kernel */ 709 movl %esi,R(physfree) /* next free page is at end of kernel */ 710 711/* Allocate Kernel Page Tables */ 712 ALLOCPAGES(NKPT) 713 movl %esi,R(_KPTphys) 714 715/* Allocate Page Table Directory */ 716 ALLOCPAGES(1) 717 movl %esi,R(_IdlePTD) 718 719/* Allocate UPAGES */ 720 ALLOCPAGES(UPAGES) 721 movl %esi,R(upa) 722 addl $KERNBASE, %esi 723 movl %esi, R(_proc0paddr) 724 725/* Allocate proc0's page table for the UPAGES. */ 726 ALLOCPAGES(1) 727 movl %esi,R(p0upt) 728 729/* Map read-only from zero to the end of the kernel text section */ 730 xorl %eax, %eax 731#ifdef BDE_DEBUGGER 732/* If the debugger is present, actually map everything read-write. */ 733 cmpl $0,R(_bdb_exists) 734 jne map_read_write 735#endif 736 movl $R(_etext),%ecx 737 addl $PAGE_MASK,%ecx 738 shrl $PAGE_SHIFT,%ecx 739 fillkptphys(0) 740 741/* Map read-write, data, bss and symbols */ 742 movl $R(_etext),%eax 743 addl $PAGE_MASK, %eax 744 andl $~PAGE_MASK, %eax 745map_read_write: 746 movl R(_KERNend),%ecx 747 subl %eax,%ecx 748 shrl $PAGE_SHIFT,%ecx 749 fillkptphys(PG_RW) 750 751/* Map page directory. */ 752 movl R(_IdlePTD), %eax 753 movl $1, %ecx 754 fillkptphys(PG_RW) 755 756/* Map proc0's page table for the UPAGES the physical way. */ 757 movl R(p0upt), %eax 758 movl $1, %ecx 759 fillkptphys(PG_RW) 760 761/* Map proc0s UPAGES the physical way */ 762 movl R(upa), %eax 763 movl $UPAGES, %ecx 764 fillkptphys(PG_RW) 765 766/* Map ISA hole */ 767 movl $ISA_HOLE_START, %eax 768 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 769 fillkptphys(PG_RW|PG_N) 770 771/* Map proc0s UPAGES in the special page table for this purpose. */ 772 movl R(upa), %eax 773 movl $KSTKPTEOFF, %ebx 774 movl $UPAGES, %ecx 775 fillkpt(R(p0upt), PG_RW) 776 777/* and put the page table in the pde. */ 778 movl R(p0upt), %eax 779 movl $KSTKPTDI, %ebx 780 movl $1, %ecx 781 fillkpt(R(_IdlePTD), PG_RW) 782 783/* install a pde for temporary double map of bottom of VA */ 784 movl R(_KPTphys), %eax 785 xorl %ebx, %ebx 786 movl $1, %ecx 787 fillkpt(R(_IdlePTD), PG_RW) 788 789/* install pde's for pt's */ 790 movl R(_KPTphys), %eax 791 movl $KPTDI, %ebx 792 movl $NKPT, %ecx 793 fillkpt(R(_IdlePTD), PG_RW) 794 795/* install a pde recursively mapping page directory as a page table */ 796 movl R(_IdlePTD), %eax 797 movl $PTDPTDI, %ebx 798 movl $1,%ecx 799 fillkpt(R(_IdlePTD), PG_RW) 800 801 ret 802 803#ifdef BDE_DEBUGGER 804bdb_prepare_paging: 805 cmpl $0,R(_bdb_exists) 806 je bdb_prepare_paging_exit 807 808 subl $6,%esp 809 810 /* 811 * Copy and convert debugger entries from the bootstrap gdt and idt 812 * to the kernel gdt and idt. Everything is still in low memory. 813 * Tracing continues to work after paging is enabled because the 814 * low memory addresses remain valid until everything is relocated. 815 * However, tracing through the setidt() that initializes the trace 816 * trap will crash. 817 */ 818 sgdt (%esp) 819 movl 2(%esp),%esi /* base address of bootstrap gdt */ 820 movl $R(_gdt),%edi 821 movl %edi,2(%esp) /* prepare to load kernel gdt */ 822 movl $8*18/4,%ecx 823 cld 824 rep /* copy gdt */ 825 movsl 826 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 827 movb $0x92,-8+5(%edi) 828 lgdt (%esp) 829 830 sidt (%esp) 831 movl 2(%esp),%esi /* base address of current idt */ 832 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 833 movw 8(%esi),%ax 834 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 835 movl 8+2(%esi),%eax 836 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 837 movl 24+4(%esi),%eax /* same for bpt descriptor */ 838 movw 24(%esi),%ax 839 movl %eax,R(bdb_bpt_ljmp+1) 840 movl 24+2(%esi),%eax 841 movw %ax,R(bdb_bpt_ljmp+5) 842 movl $R(_idt),%edi 843 movl %edi,2(%esp) /* prepare to load kernel idt */ 844 movl $8*4/4,%ecx 845 cld 846 rep /* copy idt */ 847 movsl 848 lidt (%esp) 849 850 addl $6,%esp 851 852bdb_prepare_paging_exit: 853 ret 854 855/* Relocate debugger gdt entries and gdt and idt pointers. */ 856bdb_commit_paging: 857 cmpl $0,_bdb_exists 858 je bdb_commit_paging_exit 859 860 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 861 movl $9,%ecx 862reloc_gdt: 863 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 864 addl $8,%eax /* now KERNBASE>>24 */ 865 loop reloc_gdt 866 867 subl $6,%esp 868 sgdt (%esp) 869 addl $KERNBASE,2(%esp) 870 lgdt (%esp) 871 sidt (%esp) 872 addl $KERNBASE,2(%esp) 873 lidt (%esp) 874 addl $6,%esp 875 876 int $3 877 878bdb_commit_paging_exit: 879 ret 880 881#endif /* BDE_DEBUGGER */ 882