locore.s revision 18842
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 1.74 1996/10/05 10:43:58 jkh 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_cpu.h" 48#include "opt_ddb.h" 49#include "opt_userconfig.h" 50 51#include <sys/errno.h> 52#include <sys/syscall.h> 53#include <sys/reboot.h> 54 55#include <machine/asmacros.h> 56#include <machine/cputypes.h> 57#include <machine/psl.h> 58#include <machine/pmap.h> 59#include <machine/specialreg.h> 60 61#include "assym.s" 62 63/* 64 * XXX 65 * 66 * Note: This version greatly munged to avoid various assembler errors 67 * that may be fixed in newer versions of gas. Perhaps newer versions 68 * will have more pleasant appearance. 69 */ 70 71/* 72 * PTmap is recursive pagemap at top of virtual address space. 73 * Within PTmap, the page directory can be found (third indirection). 74 */ 75 .globl _PTmap,_PTD,_PTDpde 76 .set _PTmap,(PTDPTDI << PDRSHIFT) 77 .set _PTD,_PTmap + (PTDPTDI * PAGE_SIZE) 78 .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 79 80/* 81 * APTmap, APTD is the alternate recursive pagemap. 82 * It's used when modifying another process's page tables. 83 */ 84 .globl _APTmap,_APTD,_APTDpde 85 .set _APTmap,APTDPTDI << PDRSHIFT 86 .set _APTD,_APTmap + (APTDPTDI * PAGE_SIZE) 87 .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 88 89/* 90 * Access to each processes kernel stack is via a region of 91 * per-process address space (at the beginning), immediately above 92 * the user process stack. 93 */ 94 .set _kstack,USRSTACK 95 .globl _kstack 96 97/* 98 * Globals 99 */ 100 .data 101 ALIGN_DATA /* just to be sure */ 102 103 .globl tmpstk 104 .space 0x2000 /* space for tmpstk - temporary stack */ 105tmpstk: 106 107 .globl _boothowto,_bootdev 108 109 .globl _cpu,_cpu_vendor,_cpu_id,_bootinfo 110 .globl _cpu_high, _cpu_feature 111 112_cpu: .long 0 /* are we 386, 386sx, or 486 */ 113_cpu_id: .long 0 /* stepping ID */ 114_cpu_high: .long 0 /* highest arg to CPUID */ 115_cpu_feature: .long 0 /* features */ 116_cpu_vendor: .space 20 /* CPU origin code */ 117_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 118 119_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 120physfree: .long 0 /* phys addr of next free page */ 121p0upa: .long 0 /* phys addr of proc0's UPAGES */ 122p0upt: .long 0 /* phys addr of proc0's UPAGES page table */ 123 124 .globl _IdlePTD 125_IdlePTD: .long 0 /* phys addr of kernel PTD */ 126 127_KPTphys: .long 0 /* phys addr of kernel page tables */ 128 129 .globl _proc0paddr 130_proc0paddr: .long 0 /* address of proc 0 address space */ 131 132#ifdef BDE_DEBUGGER 133 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 134_bdb_exists: .long 0 135#endif 136 137 138/********************************************************************** 139 * 140 * Some handy macros 141 * 142 */ 143 144#define R(foo) ((foo)-KERNBASE) 145 146#define ALLOCPAGES(foo) \ 147 movl R(physfree), %esi ; \ 148 movl $((foo)*PAGE_SIZE), %eax ; \ 149 addl %esi, %eax ; \ 150 movl %eax, R(physfree) ; \ 151 movl %esi, %edi ; \ 152 movl $((foo)*PAGE_SIZE),%ecx ; \ 153 xorl %eax,%eax ; \ 154 cld ; \ 155 rep ; \ 156 stosb 157 158/* 159 * fillkpt 160 * eax = page frame address 161 * ebx = index into page table 162 * ecx = how many pages to map 163 * base = base address of page dir/table 164 * prot = protection bits 165 */ 166#define fillkpt(base, prot) \ 167 shll $2, %ebx ; \ 168 addl base, %ebx ; \ 169 orl $PG_V+prot, %eax ; \ 1701: movl %eax,(%ebx) ; \ 171 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 172 addl $4,%ebx ; /* next pte */ \ 173 loop 1b 174 175/* 176 * fillkptphys(prot) 177 * eax = physical address 178 * ecx = how many pages to map 179 * prot = protection bits 180 */ 181#define fillkptphys(prot) \ 182 movl %eax, %ebx ; \ 183 shrl $PAGE_SHIFT, %ebx ; \ 184 fillkpt(R(_KPTphys), prot) 185 186 .text 187/********************************************************************** 188 * 189 * This is where the bootblocks start us, set the ball rolling... 190 * 191 */ 192NON_GPROF_ENTRY(btext) 193 194#ifdef BDE_DEBUGGER 195#ifdef BIOS_STEALS_3K 196 cmpl $0x0375c339,0x95504 197#else 198 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 199#endif 200 jne 1f 201 movb $1,R(_bdb_exists) 2021: 203#endif 204 205/* Tell the bios to warmboot next time */ 206 movw $0x1234,0x472 207 208/* Set up a real frame in case the double return in newboot is executed. */ 209 pushl %ebp 210 movl %esp, %ebp 211 212/* Don't trust what the BIOS gives for eflags. */ 213 pushl $PSL_KERNEL 214 popfl 215 216/* 217 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 218 * to set %cs, %ds, %es and %ss. 219 */ 220 mov %ds, %ax 221 mov %ax, %fs 222 mov %ax, %gs 223 224 call recover_bootinfo 225 226/* Get onto a stack that we can trust. */ 227/* 228 * XXX this step is delayed in case recover_bootinfo needs to return via 229 * the old stack, but it need not be, since recover_bootinfo actually 230 * returns via the old frame. 231 */ 232 movl $R(tmpstk),%esp 233 234 call identify_cpu 235 236/* clear bss */ 237/* 238 * XXX this should be done a little earlier. 239 * 240 * XXX we don't check that there is memory for our bss and page tables 241 * before using it. 242 * 243 * XXX the boot program somewhat bogusly clears the bss. We still have 244 * to do it in case we were unzipped by kzipboot. Then the boot program 245 * only clears kzipboot's bss. 246 * 247 * XXX the gdt and idt are still somewhere in the boot program. We 248 * depend on the convention that the boot program is below 1MB and we 249 * are above 1MB to keep the gdt and idt away from the bss and page 250 * tables. The idt is only used if BDE_DEBUGGER is enabled. 251 */ 252 movl $R(_end),%ecx 253 movl $R(_edata),%edi 254 subl %edi,%ecx 255 xorl %eax,%eax 256 cld 257 rep 258 stosb 259 260#if NAPM > 0 261/* 262 * XXX it's not clear that APM can live in the current environonment. 263 * Only pc-relative addressing works. 264 */ 265 call _apm_setup 266#endif 267 268 call create_pagetables 269 270#ifdef BDE_DEBUGGER 271/* 272 * Adjust as much as possible for paging before enabling paging so that the 273 * adjustments can be traced. 274 */ 275 call bdb_prepare_paging 276#endif 277 278/* Now enable paging */ 279 movl R(_IdlePTD), %eax 280 movl %eax,%cr3 /* load ptd addr into mmu */ 281 movl %cr0,%eax /* get control word */ 282 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 283 movl %eax,%cr0 /* and let's page NOW! */ 284 285#ifdef BDE_DEBUGGER 286/* 287 * Complete the adjustments for paging so that we can keep tracing through 288 * initi386() after the low (physical) addresses for the gdt and idt become 289 * invalid. 290 */ 291 call bdb_commit_paging 292#endif 293 294 pushl $begin /* jump to high virtualized address */ 295 ret 296 297/* now running relocated at KERNBASE where the system is linked to run */ 298begin: 299 /* set up bootstrap stack */ 300 movl $_kstack+UPAGES*PAGE_SIZE,%esp /* bootstrap stack end location */ 301 xorl %eax,%eax /* mark end of frames */ 302 movl %eax,%ebp 303 movl _proc0paddr,%eax 304 movl _IdlePTD, %esi 305 movl %esi,PCB_CR3(%eax) 306 307 movl physfree, %esi 308 pushl %esi /* value of first for init386(first) */ 309 call _init386 /* wire 386 chip for unix operation */ 310 popl %esi 311 312 .globl __ucodesel,__udatasel 313 314 pushl $0 /* unused */ 315 pushl __udatasel /* ss */ 316 pushl $0 /* esp - filled in by execve() */ 317 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 318 pushl __ucodesel /* cs */ 319 pushl $0 /* eip - filled in by execve() */ 320 subl $(12*4),%esp /* space for rest of registers */ 321 322 pushl %esp /* call main with frame pointer */ 323 call _main /* autoconfiguration, mountroot etc */ 324 325 addl $(13*4),%esp /* back to a frame we can return with */ 326 327 /* 328 * now we've run main() and determined what cpu-type we are, we can 329 * enable write protection and alignment checking on i486 cpus and 330 * above. 331 */ 332#if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU) 333 cmpl $CPUCLASS_386,_cpu_class 334 je 1f 335 movl %cr0,%eax /* get control word */ 336 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 337 movl %eax,%cr0 /* and do it */ 3381: 339#endif 340 /* 341 * on return from main(), we are process 1 342 * set up address space and stack so that we can 'return' to user mode 343 */ 344 movl __ucodesel,%eax 345 movl __udatasel,%ecx 346 347 movl %cx,%ds 348 movl %cx,%es 349 movl %ax,%fs /* double map cs to fs */ 350 movl %cx,%gs /* and ds to gs */ 351 iret /* goto user! */ 352 353#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 354 355/* 356 * Signal trampoline, copied to top of user stack 357 */ 358NON_GPROF_ENTRY(sigcode) 359 call SIGF_HANDLER(%esp) 360 lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 361 /* copy at 8(%esp)) */ 362 pushl %eax 363 pushl %eax /* junk to fake return address */ 364 movl $SYS_sigreturn,%eax /* sigreturn() */ 365 LCALL(0x7,0) /* enter kernel with args on stack */ 366 hlt /* never gets here */ 367 .align 2,0x90 /* long word text-align */ 368_esigcode: 369 370 .data 371 .globl _szsigcode 372_szsigcode: 373 .long _esigcode-_sigcode 374 .text 375 376/********************************************************************** 377 * 378 * Recover the bootinfo passed to us from the boot program 379 * 380 */ 381recover_bootinfo: 382 /* 383 * This code is called in different ways depending on what loaded 384 * and started the kernel. This is used to detect how we get the 385 * arguments from the other code and what we do with them. 386 * 387 * Old disk boot blocks: 388 * (*btext)(howto, bootdev, cyloffset, esym); 389 * [return address == 0, and can NOT be returned to] 390 * [cyloffset was not supported by the FreeBSD boot code 391 * and always passed in as 0] 392 * [esym is also known as total in the boot code, and 393 * was never properly supported by the FreeBSD boot code] 394 * 395 * Old diskless netboot code: 396 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 397 * [return address != 0, and can NOT be returned to] 398 * If we are being booted by this code it will NOT work, 399 * so we are just going to halt if we find this case. 400 * 401 * New uniform boot code: 402 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 403 * [return address != 0, and can be returned to] 404 * 405 * There may seem to be a lot of wasted arguments in here, but 406 * that is so the newer boot code can still load very old kernels 407 * and old boot code can load new kernels. 408 */ 409 410 /* 411 * The old style disk boot blocks fake a frame on the stack and 412 * did an lret to get here. The frame on the stack has a return 413 * address of 0. 414 */ 415 cmpl $0,4(%ebp) 416 je olddiskboot 417 418 /* 419 * We have some form of return address, so this is either the 420 * old diskless netboot code, or the new uniform code. That can 421 * be detected by looking at the 5th argument, if it is 0 422 * we are being booted by the new uniform boot code. 423 */ 424 cmpl $0,24(%ebp) 425 je newboot 426 427 /* 428 * Seems we have been loaded by the old diskless boot code, we 429 * don't stand a chance of running as the diskless structure 430 * changed considerably between the two, so just halt. 431 */ 432 hlt 433 434 /* 435 * We have been loaded by the new uniform boot code. 436 * Let's check the bootinfo version, and if we do not understand 437 * it we return to the loader with a status of 1 to indicate this error 438 */ 439newboot: 440 movl 28(%ebp),%ebx /* &bootinfo.version */ 441 movl BI_VERSION(%ebx),%eax 442 cmpl $1,%eax /* We only understand version 1 */ 443 je 1f 444 movl $1,%eax /* Return status */ 445 leave 446 /* 447 * XXX this returns to our caller's caller (as is required) since 448 * we didn't set up a frame and our caller did. 449 */ 450 ret 451 4521: 453 /* 454 * If we have a kernelname copy it in 455 */ 456 movl BI_KERNELNAME(%ebx),%esi 457 cmpl $0,%esi 458 je 2f /* No kernelname */ 459 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 460 movl $R(_kernelname),%edi 461 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 462 je 1f 463 movb $'/',(%edi) 464 incl %edi 465 decl %ecx 4661: 467 cld 468 rep 469 movsb 470 4712: 472 /* 473 * Determine the size of the boot loader's copy of the bootinfo 474 * struct. This is impossible to do properly because old versions 475 * of the struct don't contain a size field and there are 2 old 476 * versions with the same version number. 477 */ 478 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 479 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 480 je got_bi_size /* no, sizeless version */ 481 movl BI_SIZE(%ebx),%ecx 482got_bi_size: 483 484 /* 485 * Copy the common part of the bootinfo struct 486 */ 487 movl %ebx,%esi 488 movl $R(_bootinfo),%edi 489 cmpl $BOOTINFO_SIZE,%ecx 490 jbe got_common_bi_size 491 movl $BOOTINFO_SIZE,%ecx 492got_common_bi_size: 493 cld 494 rep 495 movsb 496 497#ifdef NFS 498 /* 499 * If we have a nfs_diskless structure copy it in 500 */ 501 movl BI_NFS_DISKLESS(%ebx),%esi 502 cmpl $0,%esi 503 je olddiskboot 504 movl $R(_nfs_diskless),%edi 505 movl $NFSDISKLESS_SIZE,%ecx 506 cld 507 rep 508 movsb 509 movl $R(_nfs_diskless_valid),%edi 510 movl $1,(%edi) 511#endif 512 513 /* 514 * The old style disk boot. 515 * (*btext)(howto, bootdev, cyloffset, esym); 516 * Note that the newer boot code just falls into here to pick 517 * up howto and bootdev, cyloffset and esym are no longer used 518 */ 519olddiskboot: 520 movl 8(%ebp),%eax 521 movl %eax,R(_boothowto) 522 movl 12(%ebp),%eax 523 movl %eax,R(_bootdev) 524 525#if defined(USERCONFIG_BOOT) && defined(USERCONFIG) 526 movl $0x10200, %esi 527 movl $R(_userconfig_from_boot),%edi 528 movl $512,%ecx 529 cld 530 rep 531 movsb 532#endif /* USERCONFIG_BOOT */ 533 534 ret 535 536 537/********************************************************************** 538 * 539 * Identify the CPU and initialize anything special about it 540 * 541 */ 542identify_cpu: 543 544 /* Try to toggle alignment check flag; does not exist on 386. */ 545 pushfl 546 popl %eax 547 movl %eax,%ecx 548 orl $PSL_AC,%eax 549 pushl %eax 550 popfl 551 pushfl 552 popl %eax 553 xorl %ecx,%eax 554 andl $PSL_AC,%eax 555 pushl %ecx 556 popfl 557 558 testl %eax,%eax 559 jnz 1f 560 movl $CPU_386,R(_cpu) 561 jmp 3f 562 5631: /* Try to toggle identification flag; does not exist on early 486s. */ 564 pushfl 565 popl %eax 566 movl %eax,%ecx 567 xorl $PSL_ID,%eax 568 pushl %eax 569 popfl 570 pushfl 571 popl %eax 572 xorl %ecx,%eax 573 andl $PSL_ID,%eax 574 pushl %ecx 575 popfl 576 577 testl %eax,%eax 578 jnz 1f 579 movl $CPU_486,R(_cpu) 580 581 /* check for Cyrix 486DLC -- based on check routine */ 582 /* documented in "Cx486SLC/e SMM Programmer's Guide" */ 583 xorw %dx,%dx 584 cmpw %dx,%dx # set flags to known state 585 pushfw 586 popw %cx # store flags in ecx 587 movw $0xffff,%ax 588 movw $0x0004,%bx 589 divw %bx 590 pushfw 591 popw %ax 592 andw $0x08d5,%ax # mask off important bits 593 andw $0x08d5,%cx 594 cmpw %ax,%cx 595 596 jnz 3f # if flags changed, Intel chip 597 598 movl $CPU_486DLC,R(_cpu) # set CPU value for Cyrix 599 movl $0x69727943,R(_cpu_vendor) # store vendor string 600 movw $0x0078,R(_cpu_vendor+4) 601 602#ifndef CYRIX_CACHE_WORKS 603 /* Disable caching of the ISA hole only. */ 604 invd 605 movb $CCR0,%al # Configuration Register index (CCR0) 606 outb %al,$0x22 607 inb $0x23,%al 608 orb $(CCR0_NC1|CCR0_BARB),%al 609 movb %al,%ah 610 movb $CCR0,%al 611 outb %al,$0x22 612 movb %ah,%al 613 outb %al,$0x23 614 invd 615#else /* CYRIX_CACHE_WORKS */ 616 /* Set cache parameters */ 617 invd # Start with guaranteed clean cache 618 movb $CCR0,%al # Configuration Register index (CCR0) 619 outb %al,$0x22 620 inb $0x23,%al 621 andb $~CCR0_NC0,%al 622#ifndef CYRIX_CACHE_REALLY_WORKS 623 orb $(CCR0_NC1|CCR0_BARB),%al 624#else /* CYRIX_CACHE_REALLY_WORKS */ 625 orb $CCR0_NC1,%al 626#endif /* !CYRIX_CACHE_REALLY_WORKS */ 627 movb %al,%ah 628 movb $CCR0,%al 629 outb %al,$0x22 630 movb %ah,%al 631 outb %al,$0x23 632 /* clear non-cacheable region 1 */ 633 movb $(NCR1+2),%al 634 outb %al,$0x22 635 movb $NCR_SIZE_0K,%al 636 outb %al,$0x23 637 /* clear non-cacheable region 2 */ 638 movb $(NCR2+2),%al 639 outb %al,$0x22 640 movb $NCR_SIZE_0K,%al 641 outb %al,$0x23 642 /* clear non-cacheable region 3 */ 643 movb $(NCR3+2),%al 644 outb %al,$0x22 645 movb $NCR_SIZE_0K,%al 646 outb %al,$0x23 647 /* clear non-cacheable region 4 */ 648 movb $(NCR4+2),%al 649 outb %al,$0x22 650 movb $NCR_SIZE_0K,%al 651 outb %al,$0x23 652 /* enable caching in CR0 */ 653 movl %cr0,%eax 654 andl $~(CR0_CD|CR0_NW),%eax 655 movl %eax,%cr0 656 invd 657#endif /* !CYRIX_CACHE_WORKS */ 658 jmp 3f 659 6601: /* Use the `cpuid' instruction. */ 661 xorl %eax,%eax 662 .byte 0x0f,0xa2 # cpuid 0 663 movl %eax,R(_cpu_high) # highest capability 664 movl %ebx,R(_cpu_vendor) # store vendor string 665 movl %edx,R(_cpu_vendor+4) 666 movl %ecx,R(_cpu_vendor+8) 667 movb $0,R(_cpu_vendor+12) 668 669 movl $1,%eax 670 .byte 0x0f,0xa2 # cpuid 1 671 movl %eax,R(_cpu_id) # store cpu_id 672 movl %edx,R(_cpu_feature) # store cpu_feature 673 rorl $8,%eax # extract family type 674 andl $15,%eax 675 cmpl $5,%eax 676 jae 1f 677 678 /* less than Pentium; must be 486 */ 679 movl $CPU_486,R(_cpu) 680 jmp 3f 6811: 682 /* a Pentium? */ 683 cmpl $5,%eax 684 jne 2f 685 movl $CPU_586,R(_cpu) 686 jmp 3f 6872: 688 /* Greater than Pentium...call it a Pentium Pro */ 689 movl $CPU_686,R(_cpu) 6903: 691 ret 692 693 694/********************************************************************** 695 * 696 * Create the first page directory and its page tables. 697 * 698 */ 699 700create_pagetables: 701 702/* Find end of kernel image (rounded up to a page boundary). */ 703 movl $R(_end),%esi 704 705/* include symbols in "kernel image" if they are loaded and useful */ 706#ifdef DDB 707 movl R(_bootinfo+BI_ESYMTAB),%edi 708 testl %edi,%edi 709 je over_symalloc 710 movl %edi,%esi 711 movl $KERNBASE,%edi 712 addl %edi,R(_bootinfo+BI_SYMTAB) 713 addl %edi,R(_bootinfo+BI_ESYMTAB) 714over_symalloc: 715#endif 716 717 addl $PAGE_MASK,%esi 718 andl $~PAGE_MASK,%esi 719 movl %esi,R(_KERNend) /* save end of kernel */ 720 movl %esi,R(physfree) /* next free page is at end of kernel */ 721 722/* Allocate Kernel Page Tables */ 723 ALLOCPAGES(NKPT) 724 movl %esi,R(_KPTphys) 725 726/* Allocate Page Table Directory */ 727 ALLOCPAGES(1) 728 movl %esi,R(_IdlePTD) 729 730/* Allocate UPAGES */ 731 ALLOCPAGES(UPAGES) 732 movl %esi,R(p0upa) 733 addl $KERNBASE, %esi 734 movl %esi, R(_proc0paddr) 735 736/* Allocate proc0's page table for the UPAGES. */ 737 ALLOCPAGES(1) 738 movl %esi,R(p0upt) 739 740/* Map read-only from zero to the end of the kernel text section */ 741 xorl %eax, %eax 742#ifdef BDE_DEBUGGER 743/* If the debugger is present, actually map everything read-write. */ 744 cmpl $0,R(_bdb_exists) 745 jne map_read_write 746#endif 747 movl $R(_etext),%ecx 748 addl $PAGE_MASK,%ecx 749 shrl $PAGE_SHIFT,%ecx 750 fillkptphys(0) 751 752/* Map read-write, data, bss and symbols */ 753 movl $R(_etext),%eax 754 addl $PAGE_MASK, %eax 755 andl $~PAGE_MASK, %eax 756map_read_write: 757 movl R(_KERNend),%ecx 758 subl %eax,%ecx 759 shrl $PAGE_SHIFT,%ecx 760 fillkptphys(PG_RW) 761 762/* Map page directory. */ 763 movl R(_IdlePTD), %eax 764 movl $1, %ecx 765 fillkptphys(PG_RW) 766 767/* Map proc0's page table for the UPAGES. */ 768 movl R(p0upt), %eax 769 movl $1, %ecx 770 fillkptphys(PG_RW) 771 772/* Map proc0's UPAGES in the physical way ... */ 773 movl R(p0upa), %eax 774 movl $UPAGES, %ecx 775 fillkptphys(PG_RW) 776 777/* Map ISA hole */ 778 movl $ISA_HOLE_START, %eax 779 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 780 fillkptphys(PG_RW|PG_N) 781 782/* Map proc0s UPAGES in the special page table for this purpose ... */ 783 movl R(p0upa), %eax 784 movl $KSTKPTEOFF, %ebx 785 movl $UPAGES, %ecx 786 fillkpt(R(p0upt), PG_RW) 787 788/* ... and put the page table in the pde. */ 789 movl R(p0upt), %eax 790 movl $KSTKPTDI, %ebx 791 movl $1, %ecx 792 fillkpt(R(_IdlePTD), PG_RW) 793 794/* install a pde for temporary double map of bottom of VA */ 795 movl R(_KPTphys), %eax 796 xorl %ebx, %ebx 797 movl $1, %ecx 798 fillkpt(R(_IdlePTD), PG_RW) 799 800/* install pde's for pt's */ 801 movl R(_KPTphys), %eax 802 movl $KPTDI, %ebx 803 movl $NKPT, %ecx 804 fillkpt(R(_IdlePTD), PG_RW) 805 806/* install a pde recursively mapping page directory as a page table */ 807 movl R(_IdlePTD), %eax 808 movl $PTDPTDI, %ebx 809 movl $1,%ecx 810 fillkpt(R(_IdlePTD), PG_RW) 811 812 ret 813 814#ifdef BDE_DEBUGGER 815bdb_prepare_paging: 816 cmpl $0,R(_bdb_exists) 817 je bdb_prepare_paging_exit 818 819 subl $6,%esp 820 821 /* 822 * Copy and convert debugger entries from the bootstrap gdt and idt 823 * to the kernel gdt and idt. Everything is still in low memory. 824 * Tracing continues to work after paging is enabled because the 825 * low memory addresses remain valid until everything is relocated. 826 * However, tracing through the setidt() that initializes the trace 827 * trap will crash. 828 */ 829 sgdt (%esp) 830 movl 2(%esp),%esi /* base address of bootstrap gdt */ 831 movl $R(_gdt),%edi 832 movl %edi,2(%esp) /* prepare to load kernel gdt */ 833 movl $8*18/4,%ecx 834 cld 835 rep /* copy gdt */ 836 movsl 837 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 838 movb $0x92,-8+5(%edi) 839 lgdt (%esp) 840 841 sidt (%esp) 842 movl 2(%esp),%esi /* base address of current idt */ 843 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 844 movw 8(%esi),%ax 845 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 846 movl 8+2(%esi),%eax 847 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 848 movl 24+4(%esi),%eax /* same for bpt descriptor */ 849 movw 24(%esi),%ax 850 movl %eax,R(bdb_bpt_ljmp+1) 851 movl 24+2(%esi),%eax 852 movw %ax,R(bdb_bpt_ljmp+5) 853 movl $R(_idt),%edi 854 movl %edi,2(%esp) /* prepare to load kernel idt */ 855 movl $8*4/4,%ecx 856 cld 857 rep /* copy idt */ 858 movsl 859 lidt (%esp) 860 861 addl $6,%esp 862 863bdb_prepare_paging_exit: 864 ret 865 866/* Relocate debugger gdt entries and gdt and idt pointers. */ 867bdb_commit_paging: 868 cmpl $0,_bdb_exists 869 je bdb_commit_paging_exit 870 871 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 872 movl $9,%ecx 873reloc_gdt: 874 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 875 addl $8,%eax /* now KERNBASE>>24 */ 876 loop reloc_gdt 877 878 subl $6,%esp 879 sgdt (%esp) 880 addl $KERNBASE,2(%esp) 881 lgdt (%esp) 882 sidt (%esp) 883 addl $KERNBASE,2(%esp) 884 lidt (%esp) 885 addl $6,%esp 886 887 int $3 888 889bdb_commit_paging_exit: 890 ret 891 892#endif /* BDE_DEBUGGER */ 893