locore.s revision 18702
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 1.73 1996/07/12 06:48:55 bde 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#include "opt_userconfig.h" 49 50#include <sys/errno.h> 51#include <sys/syscall.h> 52#include <sys/reboot.h> 53 54#include <machine/asmacros.h> 55#include <machine/cputypes.h> 56#include <machine/psl.h> 57#include <machine/pmap.h> 58#include <machine/specialreg.h> 59 60#include "assym.s" 61 62/* 63 * XXX 64 * 65 * Note: This version greatly munged to avoid various assembler errors 66 * that may be fixed in newer versions of gas. Perhaps newer versions 67 * will have more pleasant appearance. 68 */ 69 70/* 71 * PTmap is recursive pagemap at top of virtual address space. 72 * Within PTmap, the page directory can be found (third indirection). 73 */ 74 .globl _PTmap,_PTD,_PTDpde 75 .set _PTmap,(PTDPTDI << PDRSHIFT) 76 .set _PTD,_PTmap + (PTDPTDI * PAGE_SIZE) 77 .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 78 79/* 80 * APTmap, APTD is the alternate recursive pagemap. 81 * It's used when modifying another process's page tables. 82 */ 83 .globl _APTmap,_APTD,_APTDpde 84 .set _APTmap,APTDPTDI << PDRSHIFT 85 .set _APTD,_APTmap + (APTDPTDI * PAGE_SIZE) 86 .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 87 88/* 89 * Access to each processes kernel stack is via a region of 90 * per-process address space (at the beginning), immediately above 91 * the user process stack. 92 */ 93 .set _kstack,USRSTACK 94 .globl _kstack 95 96/* 97 * Globals 98 */ 99 .data 100 ALIGN_DATA /* just to be sure */ 101 102 .globl tmpstk 103 .space 0x2000 /* space for tmpstk - temporary stack */ 104tmpstk: 105 106 .globl _boothowto,_bootdev 107 108 .globl _cpu,_cpu_vendor,_cpu_id,_bootinfo 109 .globl _cpu_high, _cpu_feature 110 111_cpu: .long 0 /* are we 386, 386sx, or 486 */ 112_cpu_id: .long 0 /* stepping ID */ 113_cpu_high: .long 0 /* highest arg to CPUID */ 114_cpu_feature: .long 0 /* features */ 115_cpu_vendor: .space 20 /* CPU origin code */ 116_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 117 118_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 119physfree: .long 0 /* phys addr of next free page */ 120p0upa: .long 0 /* phys addr of proc0's UPAGES */ 121p0upt: .long 0 /* phys addr of proc0's UPAGES page table */ 122 123 .globl _IdlePTD 124_IdlePTD: .long 0 /* phys addr of kernel PTD */ 125 126_KPTphys: .long 0 /* phys addr of kernel page tables */ 127 128 .globl _proc0paddr 129_proc0paddr: .long 0 /* address of proc 0 address space */ 130 131#ifdef BDE_DEBUGGER 132 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 133_bdb_exists: .long 0 134#endif 135 136 137/********************************************************************** 138 * 139 * Some handy macros 140 * 141 */ 142 143#define R(foo) ((foo)-KERNBASE) 144 145#define ALLOCPAGES(foo) \ 146 movl R(physfree), %esi ; \ 147 movl $((foo)*PAGE_SIZE), %eax ; \ 148 addl %esi, %eax ; \ 149 movl %eax, R(physfree) ; \ 150 movl %esi, %edi ; \ 151 movl $((foo)*PAGE_SIZE),%ecx ; \ 152 xorl %eax,%eax ; \ 153 cld ; \ 154 rep ; \ 155 stosb 156 157/* 158 * fillkpt 159 * eax = page frame address 160 * ebx = index into page table 161 * ecx = how many pages to map 162 * base = base address of page dir/table 163 * prot = protection bits 164 */ 165#define fillkpt(base, prot) \ 166 shll $2, %ebx ; \ 167 addl base, %ebx ; \ 168 orl $PG_V+prot, %eax ; \ 1691: movl %eax,(%ebx) ; \ 170 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 171 addl $4,%ebx ; /* next pte */ \ 172 loop 1b 173 174/* 175 * fillkptphys(prot) 176 * eax = physical address 177 * ecx = how many pages to map 178 * prot = protection bits 179 */ 180#define fillkptphys(prot) \ 181 movl %eax, %ebx ; \ 182 shrl $PAGE_SHIFT, %ebx ; \ 183 fillkpt(R(_KPTphys), prot) 184 185 .text 186/********************************************************************** 187 * 188 * This is where the bootblocks start us, set the ball rolling... 189 * 190 */ 191NON_GPROF_ENTRY(btext) 192 193#ifdef BDE_DEBUGGER 194#ifdef BIOS_STEALS_3K 195 cmpl $0x0375c339,0x95504 196#else 197 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 198#endif 199 jne 1f 200 movb $1,R(_bdb_exists) 2011: 202#endif 203 204/* Tell the bios to warmboot next time */ 205 movw $0x1234,0x472 206 207/* Set up a real frame in case the double return in newboot is executed. */ 208 pushl %ebp 209 movl %esp, %ebp 210 211/* Don't trust what the BIOS gives for eflags. */ 212 pushl $PSL_KERNEL 213 popfl 214 215/* 216 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 217 * to set %cs, %ds, %es and %ss. 218 */ 219 mov %ds, %ax 220 mov %ax, %fs 221 mov %ax, %gs 222 223 call recover_bootinfo 224 225/* Get onto a stack that we can trust. */ 226/* 227 * XXX this step is delayed in case recover_bootinfo needs to return via 228 * the old stack, but it need not be, since recover_bootinfo actually 229 * returns via the old frame. 230 */ 231 movl $R(tmpstk),%esp 232 233 call identify_cpu 234 235/* clear bss */ 236/* 237 * XXX this should be done a little earlier. 238 * 239 * XXX we don't check that there is memory for our bss and page tables 240 * before using it. 241 * 242 * XXX the boot program somewhat bogusly clears the bss. We still have 243 * to do it in case we were unzipped by kzipboot. Then the boot program 244 * only clears kzipboot's bss. 245 * 246 * XXX the gdt and idt are still somewhere in the boot program. We 247 * depend on the convention that the boot program is below 1MB and we 248 * are above 1MB to keep the gdt and idt away from the bss and page 249 * tables. The idt is only used if BDE_DEBUGGER is enabled. 250 */ 251 movl $R(_end),%ecx 252 movl $R(_edata),%edi 253 subl %edi,%ecx 254 xorl %eax,%eax 255 cld 256 rep 257 stosb 258 259#if NAPM > 0 260/* 261 * XXX it's not clear that APM can live in the current environonment. 262 * Only pc-relative addressing works. 263 */ 264 call _apm_setup 265#endif 266 267 call create_pagetables 268 269#ifdef BDE_DEBUGGER 270/* 271 * Adjust as much as possible for paging before enabling paging so that the 272 * adjustments can be traced. 273 */ 274 call bdb_prepare_paging 275#endif 276 277/* Now enable paging */ 278 movl R(_IdlePTD), %eax 279 movl %eax,%cr3 /* load ptd addr into mmu */ 280 movl %cr0,%eax /* get control word */ 281 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 282 movl %eax,%cr0 /* and let's page NOW! */ 283 284#ifdef BDE_DEBUGGER 285/* 286 * Complete the adjustments for paging so that we can keep tracing through 287 * initi386() after the low (physical) addresses for the gdt and idt become 288 * invalid. 289 */ 290 call bdb_commit_paging 291#endif 292 293 pushl $begin /* jump to high virtualized address */ 294 ret 295 296/* now running relocated at KERNBASE where the system is linked to run */ 297begin: 298 /* set up bootstrap stack */ 299 movl $_kstack+UPAGES*PAGE_SIZE,%esp /* bootstrap stack end location */ 300 xorl %eax,%eax /* mark end of frames */ 301 movl %eax,%ebp 302 movl _proc0paddr,%eax 303 movl _IdlePTD, %esi 304 movl %esi,PCB_CR3(%eax) 305 306 movl physfree, %esi 307 pushl %esi /* value of first for init386(first) */ 308 call _init386 /* wire 386 chip for unix operation */ 309 popl %esi 310 311 .globl __ucodesel,__udatasel 312 313 pushl $0 /* unused */ 314 pushl __udatasel /* ss */ 315 pushl $0 /* esp - filled in by execve() */ 316 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 317 pushl __ucodesel /* cs */ 318 pushl $0 /* eip - filled in by execve() */ 319 subl $(12*4),%esp /* space for rest of registers */ 320 321 pushl %esp /* call main with frame pointer */ 322 call _main /* autoconfiguration, mountroot etc */ 323 324 addl $(13*4),%esp /* back to a frame we can return with */ 325 326 /* 327 * now we've run main() and determined what cpu-type we are, we can 328 * enable write protection and alignment checking on i486 cpus and 329 * above. 330 */ 331#if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU) 332 cmpl $CPUCLASS_386,_cpu_class 333 je 1f 334 movl %cr0,%eax /* get control word */ 335 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 336 movl %eax,%cr0 /* and do it */ 3371: 338#endif 339 /* 340 * on return from main(), we are process 1 341 * set up address space and stack so that we can 'return' to user mode 342 */ 343 movl __ucodesel,%eax 344 movl __udatasel,%ecx 345 346 movl %cx,%ds 347 movl %cx,%es 348 movl %ax,%fs /* double map cs to fs */ 349 movl %cx,%gs /* and ds to gs */ 350 iret /* goto user! */ 351 352#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 353 354/* 355 * Signal trampoline, copied to top of user stack 356 */ 357NON_GPROF_ENTRY(sigcode) 358 call SIGF_HANDLER(%esp) 359 lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 360 /* copy at 8(%esp)) */ 361 pushl %eax 362 pushl %eax /* junk to fake return address */ 363 movl $SYS_sigreturn,%eax /* sigreturn() */ 364 LCALL(0x7,0) /* enter kernel with args on stack */ 365 hlt /* never gets here */ 366 .align 2,0x90 /* long word text-align */ 367_esigcode: 368 369 .data 370 .globl _szsigcode 371_szsigcode: 372 .long _esigcode-_sigcode 373 .text 374 375/********************************************************************** 376 * 377 * Recover the bootinfo passed to us from the boot program 378 * 379 */ 380recover_bootinfo: 381 /* 382 * This code is called in different ways depending on what loaded 383 * and started the kernel. This is used to detect how we get the 384 * arguments from the other code and what we do with them. 385 * 386 * Old disk boot blocks: 387 * (*btext)(howto, bootdev, cyloffset, esym); 388 * [return address == 0, and can NOT be returned to] 389 * [cyloffset was not supported by the FreeBSD boot code 390 * and always passed in as 0] 391 * [esym is also known as total in the boot code, and 392 * was never properly supported by the FreeBSD boot code] 393 * 394 * Old diskless netboot code: 395 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 396 * [return address != 0, and can NOT be returned to] 397 * If we are being booted by this code it will NOT work, 398 * so we are just going to halt if we find this case. 399 * 400 * New uniform boot code: 401 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 402 * [return address != 0, and can be returned to] 403 * 404 * There may seem to be a lot of wasted arguments in here, but 405 * that is so the newer boot code can still load very old kernels 406 * and old boot code can load new kernels. 407 */ 408 409 /* 410 * The old style disk boot blocks fake a frame on the stack and 411 * did an lret to get here. The frame on the stack has a return 412 * address of 0. 413 */ 414 cmpl $0,4(%ebp) 415 je olddiskboot 416 417 /* 418 * We have some form of return address, so this is either the 419 * old diskless netboot code, or the new uniform code. That can 420 * be detected by looking at the 5th argument, if it is 0 421 * we are being booted by the new uniform boot code. 422 */ 423 cmpl $0,24(%ebp) 424 je newboot 425 426 /* 427 * Seems we have been loaded by the old diskless boot code, we 428 * don't stand a chance of running as the diskless structure 429 * changed considerably between the two, so just halt. 430 */ 431 hlt 432 433 /* 434 * We have been loaded by the new uniform boot code. 435 * Let's check the bootinfo version, and if we do not understand 436 * it we return to the loader with a status of 1 to indicate this error 437 */ 438newboot: 439 movl 28(%ebp),%ebx /* &bootinfo.version */ 440 movl BI_VERSION(%ebx),%eax 441 cmpl $1,%eax /* We only understand version 1 */ 442 je 1f 443 movl $1,%eax /* Return status */ 444 leave 445 /* 446 * XXX this returns to our caller's caller (as is required) since 447 * we didn't set up a frame and our caller did. 448 */ 449 ret 450 4511: 452 /* 453 * If we have a kernelname copy it in 454 */ 455 movl BI_KERNELNAME(%ebx),%esi 456 cmpl $0,%esi 457 je 2f /* No kernelname */ 458 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 459 movl $R(_kernelname),%edi 460 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 461 je 1f 462 movb $'/',(%edi) 463 incl %edi 464 decl %ecx 4651: 466 cld 467 rep 468 movsb 469 4702: 471 /* 472 * Determine the size of the boot loader's copy of the bootinfo 473 * struct. This is impossible to do properly because old versions 474 * of the struct don't contain a size field and there are 2 old 475 * versions with the same version number. 476 */ 477 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 478 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 479 je got_bi_size /* no, sizeless version */ 480 movl BI_SIZE(%ebx),%ecx 481got_bi_size: 482 483 /* 484 * Copy the common part of the bootinfo struct 485 */ 486 movl %ebx,%esi 487 movl $R(_bootinfo),%edi 488 cmpl $BOOTINFO_SIZE,%ecx 489 jbe got_common_bi_size 490 movl $BOOTINFO_SIZE,%ecx 491got_common_bi_size: 492 cld 493 rep 494 movsb 495 496#ifdef NFS 497 /* 498 * If we have a nfs_diskless structure copy it in 499 */ 500 movl BI_NFS_DISKLESS(%ebx),%esi 501 cmpl $0,%esi 502 je olddiskboot 503 movl $R(_nfs_diskless),%edi 504 movl $NFSDISKLESS_SIZE,%ecx 505 cld 506 rep 507 movsb 508 movl $R(_nfs_diskless_valid),%edi 509 movl $1,(%edi) 510#endif 511 512 /* 513 * The old style disk boot. 514 * (*btext)(howto, bootdev, cyloffset, esym); 515 * Note that the newer boot code just falls into here to pick 516 * up howto and bootdev, cyloffset and esym are no longer used 517 */ 518olddiskboot: 519 movl 8(%ebp),%eax 520 movl %eax,R(_boothowto) 521 movl 12(%ebp),%eax 522 movl %eax,R(_bootdev) 523 524#if defined(USERCONFIG_BOOT) && defined(USERCONFIG) 525 movl $0x10200, %esi 526 movl $R(_userconfig_from_boot),%edi 527 movl $512,%ecx 528 cld 529 rep 530 movsb 531#endif /* USERCONFIG_BOOT */ 532 533 ret 534 535 536/********************************************************************** 537 * 538 * Identify the CPU and initialize anything special about it 539 * 540 */ 541identify_cpu: 542 543 /* Try to toggle alignment check flag; does not exist on 386. */ 544 pushfl 545 popl %eax 546 movl %eax,%ecx 547 orl $PSL_AC,%eax 548 pushl %eax 549 popfl 550 pushfl 551 popl %eax 552 xorl %ecx,%eax 553 andl $PSL_AC,%eax 554 pushl %ecx 555 popfl 556 557 testl %eax,%eax 558 jnz 1f 559 movl $CPU_386,R(_cpu) 560 jmp 3f 561 5621: /* Try to toggle identification flag; does not exist on early 486s. */ 563 pushfl 564 popl %eax 565 movl %eax,%ecx 566 xorl $PSL_ID,%eax 567 pushl %eax 568 popfl 569 pushfl 570 popl %eax 571 xorl %ecx,%eax 572 andl $PSL_ID,%eax 573 pushl %ecx 574 popfl 575 576 testl %eax,%eax 577 jnz 1f 578 movl $CPU_486,R(_cpu) 579 580 /* check for Cyrix 486DLC -- based on check routine */ 581 /* documented in "Cx486SLC/e SMM Programmer's Guide" */ 582 xorw %dx,%dx 583 cmpw %dx,%dx # set flags to known state 584 pushfw 585 popw %cx # store flags in ecx 586 movw $0xffff,%ax 587 movw $0x0004,%bx 588 divw %bx 589 pushfw 590 popw %ax 591 andw $0x08d5,%ax # mask off important bits 592 andw $0x08d5,%cx 593 cmpw %ax,%cx 594 595 jnz 3f # if flags changed, Intel chip 596 597 movl $CPU_486DLC,R(_cpu) # set CPU value for Cyrix 598 movl $0x69727943,R(_cpu_vendor) # store vendor string 599 movw $0x0078,R(_cpu_vendor+4) 600 601#ifndef CYRIX_CACHE_WORKS 602 /* Disable caching of the ISA hole only. */ 603 invd 604 movb $CCR0,%al # Configuration Register index (CCR0) 605 outb %al,$0x22 606 inb $0x23,%al 607 orb $(CCR0_NC1|CCR0_BARB),%al 608 movb %al,%ah 609 movb $CCR0,%al 610 outb %al,$0x22 611 movb %ah,%al 612 outb %al,$0x23 613 invd 614#else /* CYRIX_CACHE_WORKS */ 615 /* Set cache parameters */ 616 invd # Start with guaranteed clean cache 617 movb $CCR0,%al # Configuration Register index (CCR0) 618 outb %al,$0x22 619 inb $0x23,%al 620 andb $~CCR0_NC0,%al 621#ifndef CYRIX_CACHE_REALLY_WORKS 622 orb $(CCR0_NC1|CCR0_BARB),%al 623#else /* CYRIX_CACHE_REALLY_WORKS */ 624 orb $CCR0_NC1,%al 625#endif /* !CYRIX_CACHE_REALLY_WORKS */ 626 movb %al,%ah 627 movb $CCR0,%al 628 outb %al,$0x22 629 movb %ah,%al 630 outb %al,$0x23 631 /* clear non-cacheable region 1 */ 632 movb $(NCR1+2),%al 633 outb %al,$0x22 634 movb $NCR_SIZE_0K,%al 635 outb %al,$0x23 636 /* clear non-cacheable region 2 */ 637 movb $(NCR2+2),%al 638 outb %al,$0x22 639 movb $NCR_SIZE_0K,%al 640 outb %al,$0x23 641 /* clear non-cacheable region 3 */ 642 movb $(NCR3+2),%al 643 outb %al,$0x22 644 movb $NCR_SIZE_0K,%al 645 outb %al,$0x23 646 /* clear non-cacheable region 4 */ 647 movb $(NCR4+2),%al 648 outb %al,$0x22 649 movb $NCR_SIZE_0K,%al 650 outb %al,$0x23 651 /* enable caching in CR0 */ 652 movl %cr0,%eax 653 andl $~(CR0_CD|CR0_NW),%eax 654 movl %eax,%cr0 655 invd 656#endif /* !CYRIX_CACHE_WORKS */ 657 jmp 3f 658 6591: /* Use the `cpuid' instruction. */ 660 xorl %eax,%eax 661 .byte 0x0f,0xa2 # cpuid 0 662 movl %eax,R(_cpu_high) # highest capability 663 movl %ebx,R(_cpu_vendor) # store vendor string 664 movl %edx,R(_cpu_vendor+4) 665 movl %ecx,R(_cpu_vendor+8) 666 movb $0,R(_cpu_vendor+12) 667 668 movl $1,%eax 669 .byte 0x0f,0xa2 # cpuid 1 670 movl %eax,R(_cpu_id) # store cpu_id 671 movl %edx,R(_cpu_feature) # store cpu_feature 672 rorl $8,%eax # extract family type 673 andl $15,%eax 674 cmpl $5,%eax 675 jae 1f 676 677 /* less than Pentium; must be 486 */ 678 movl $CPU_486,R(_cpu) 679 jmp 3f 6801: 681 /* a Pentium? */ 682 cmpl $5,%eax 683 jne 2f 684 movl $CPU_586,R(_cpu) 685 jmp 3f 6862: 687 /* Greater than Pentium...call it a Pentium Pro */ 688 movl $CPU_686,R(_cpu) 6893: 690 ret 691 692 693/********************************************************************** 694 * 695 * Create the first page directory and its page tables. 696 * 697 */ 698 699create_pagetables: 700 701/* Find end of kernel image (rounded up to a page boundary). */ 702 movl $R(_end),%esi 703 704/* include symbols in "kernel image" if they are loaded and useful */ 705#ifdef DDB 706 movl R(_bootinfo+BI_ESYMTAB),%edi 707 testl %edi,%edi 708 je over_symalloc 709 movl %edi,%esi 710 movl $KERNBASE,%edi 711 addl %edi,R(_bootinfo+BI_SYMTAB) 712 addl %edi,R(_bootinfo+BI_ESYMTAB) 713over_symalloc: 714#endif 715 716 addl $PAGE_MASK,%esi 717 andl $~PAGE_MASK,%esi 718 movl %esi,R(_KERNend) /* save end of kernel */ 719 movl %esi,R(physfree) /* next free page is at end of kernel */ 720 721/* Allocate Kernel Page Tables */ 722 ALLOCPAGES(NKPT) 723 movl %esi,R(_KPTphys) 724 725/* Allocate Page Table Directory */ 726 ALLOCPAGES(1) 727 movl %esi,R(_IdlePTD) 728 729/* Allocate UPAGES */ 730 ALLOCPAGES(UPAGES) 731 movl %esi,R(p0upa) 732 addl $KERNBASE, %esi 733 movl %esi, R(_proc0paddr) 734 735/* Allocate proc0's page table for the UPAGES. */ 736 ALLOCPAGES(1) 737 movl %esi,R(p0upt) 738 739/* Map read-only from zero to the end of the kernel text section */ 740 xorl %eax, %eax 741#ifdef BDE_DEBUGGER 742/* If the debugger is present, actually map everything read-write. */ 743 cmpl $0,R(_bdb_exists) 744 jne map_read_write 745#endif 746 movl $R(_etext),%ecx 747 addl $PAGE_MASK,%ecx 748 shrl $PAGE_SHIFT,%ecx 749 fillkptphys(0) 750 751/* Map read-write, data, bss and symbols */ 752 movl $R(_etext),%eax 753 addl $PAGE_MASK, %eax 754 andl $~PAGE_MASK, %eax 755map_read_write: 756 movl R(_KERNend),%ecx 757 subl %eax,%ecx 758 shrl $PAGE_SHIFT,%ecx 759 fillkptphys(PG_RW) 760 761/* Map page directory. */ 762 movl R(_IdlePTD), %eax 763 movl $1, %ecx 764 fillkptphys(PG_RW) 765 766/* Map proc0's page table for the UPAGES. */ 767 movl R(p0upt), %eax 768 movl $1, %ecx 769 fillkptphys(PG_RW) 770 771/* Map proc0's UPAGES in the physical way ... */ 772 movl R(p0upa), %eax 773 movl $UPAGES, %ecx 774 fillkptphys(PG_RW) 775 776/* Map ISA hole */ 777 movl $ISA_HOLE_START, %eax 778 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 779 fillkptphys(PG_RW|PG_N) 780 781/* Map proc0s UPAGES in the special page table for this purpose ... */ 782 movl R(p0upa), %eax 783 movl $KSTKPTEOFF, %ebx 784 movl $UPAGES, %ecx 785 fillkpt(R(p0upt), PG_RW) 786 787/* ... and put the page table in the pde. */ 788 movl R(p0upt), %eax 789 movl $KSTKPTDI, %ebx 790 movl $1, %ecx 791 fillkpt(R(_IdlePTD), PG_RW) 792 793/* install a pde for temporary double map of bottom of VA */ 794 movl R(_KPTphys), %eax 795 xorl %ebx, %ebx 796 movl $1, %ecx 797 fillkpt(R(_IdlePTD), PG_RW) 798 799/* install pde's for pt's */ 800 movl R(_KPTphys), %eax 801 movl $KPTDI, %ebx 802 movl $NKPT, %ecx 803 fillkpt(R(_IdlePTD), PG_RW) 804 805/* install a pde recursively mapping page directory as a page table */ 806 movl R(_IdlePTD), %eax 807 movl $PTDPTDI, %ebx 808 movl $1,%ecx 809 fillkpt(R(_IdlePTD), PG_RW) 810 811 ret 812 813#ifdef BDE_DEBUGGER 814bdb_prepare_paging: 815 cmpl $0,R(_bdb_exists) 816 je bdb_prepare_paging_exit 817 818 subl $6,%esp 819 820 /* 821 * Copy and convert debugger entries from the bootstrap gdt and idt 822 * to the kernel gdt and idt. Everything is still in low memory. 823 * Tracing continues to work after paging is enabled because the 824 * low memory addresses remain valid until everything is relocated. 825 * However, tracing through the setidt() that initializes the trace 826 * trap will crash. 827 */ 828 sgdt (%esp) 829 movl 2(%esp),%esi /* base address of bootstrap gdt */ 830 movl $R(_gdt),%edi 831 movl %edi,2(%esp) /* prepare to load kernel gdt */ 832 movl $8*18/4,%ecx 833 cld 834 rep /* copy gdt */ 835 movsl 836 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 837 movb $0x92,-8+5(%edi) 838 lgdt (%esp) 839 840 sidt (%esp) 841 movl 2(%esp),%esi /* base address of current idt */ 842 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 843 movw 8(%esi),%ax 844 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 845 movl 8+2(%esi),%eax 846 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 847 movl 24+4(%esi),%eax /* same for bpt descriptor */ 848 movw 24(%esi),%ax 849 movl %eax,R(bdb_bpt_ljmp+1) 850 movl 24+2(%esi),%eax 851 movw %ax,R(bdb_bpt_ljmp+5) 852 movl $R(_idt),%edi 853 movl %edi,2(%esp) /* prepare to load kernel idt */ 854 movl $8*4/4,%ecx 855 cld 856 rep /* copy idt */ 857 movsl 858 lidt (%esp) 859 860 addl $6,%esp 861 862bdb_prepare_paging_exit: 863 ret 864 865/* Relocate debugger gdt entries and gdt and idt pointers. */ 866bdb_commit_paging: 867 cmpl $0,_bdb_exists 868 je bdb_commit_paging_exit 869 870 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 871 movl $9,%ecx 872reloc_gdt: 873 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 874 addl $8,%eax /* now KERNBASE>>24 */ 875 loop reloc_gdt 876 877 subl $6,%esp 878 sgdt (%esp) 879 addl $KERNBASE,2(%esp) 880 lgdt (%esp) 881 sidt (%esp) 882 addl $KERNBASE,2(%esp) 883 lidt (%esp) 884 addl $6,%esp 885 886 int $3 887 888bdb_commit_paging_exit: 889 ret 890 891#endif /* BDE_DEBUGGER */ 892