locore.s revision 22130
1/*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * William Jolitz. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: @(#)locore.s 7.3 (Berkeley) 5/13/91 37 * $FreeBSD: head/sys/i386/i386/locore.s 22130 1997-01-30 20:22:02Z dg $ 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,%eax ; \ 170 orl prot,%eax ; \ 1711: movl %eax,(%ebx) ; \ 172 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 173 addl $4,%ebx ; /* next pte */ \ 174 loop 1b 175 176/* 177 * fillkptphys(prot) 178 * eax = physical address 179 * ecx = how many pages to map 180 * prot = protection bits 181 */ 182#define fillkptphys(prot) \ 183 movl %eax, %ebx ; \ 184 shrl $PAGE_SHIFT, %ebx ; \ 185 fillkpt(R(_KPTphys), prot) 186 187 .text 188/********************************************************************** 189 * 190 * This is where the bootblocks start us, set the ball rolling... 191 * 192 */ 193NON_GPROF_ENTRY(btext) 194 195#ifdef BDE_DEBUGGER 196#ifdef BIOS_STEALS_3K 197 cmpl $0x0375c339,0x95504 198#else 199 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 200#endif 201 jne 1f 202 movb $1,R(_bdb_exists) 2031: 204#endif 205 206/* Tell the bios to warmboot next time */ 207 movw $0x1234,0x472 208 209/* Set up a real frame in case the double return in newboot is executed. */ 210 pushl %ebp 211 movl %esp, %ebp 212 213/* Don't trust what the BIOS gives for eflags. */ 214 pushl $PSL_KERNEL 215 popfl 216 217/* 218 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 219 * to set %cs, %ds, %es and %ss. 220 */ 221 mov %ds, %ax 222 mov %ax, %fs 223 mov %ax, %gs 224 225 call recover_bootinfo 226 227/* Get onto a stack that we can trust. */ 228/* 229 * XXX this step is delayed in case recover_bootinfo needs to return via 230 * the old stack, but it need not be, since recover_bootinfo actually 231 * returns via the old frame. 232 */ 233 movl $R(tmpstk),%esp 234 235 call identify_cpu 236 237/* clear bss */ 238/* 239 * XXX this should be done a little earlier. 240 * 241 * XXX we don't check that there is memory for our bss and page tables 242 * before using it. 243 * 244 * XXX the boot program somewhat bogusly clears the bss. We still have 245 * to do it in case we were unzipped by kzipboot. Then the boot program 246 * only clears kzipboot's bss. 247 * 248 * XXX the gdt and idt are still somewhere in the boot program. We 249 * depend on the convention that the boot program is below 1MB and we 250 * are above 1MB to keep the gdt and idt away from the bss and page 251 * tables. The idt is only used if BDE_DEBUGGER is enabled. 252 */ 253 movl $R(_end),%ecx 254 movl $R(_edata),%edi 255 subl %edi,%ecx 256 xorl %eax,%eax 257 cld 258 rep 259 stosb 260 261#if NAPM > 0 262/* 263 * XXX it's not clear that APM can live in the current environonment. 264 * Only pc-relative addressing works. 265 */ 266 call _apm_setup 267#endif 268 269 call create_pagetables 270 271#ifdef BDE_DEBUGGER 272/* 273 * Adjust as much as possible for paging before enabling paging so that the 274 * adjustments can be traced. 275 */ 276 call bdb_prepare_paging 277#endif 278 279/* Now enable paging */ 280 movl R(_IdlePTD), %eax 281 movl %eax,%cr3 /* load ptd addr into mmu */ 282 movl %cr0,%eax /* get control word */ 283 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 284 movl %eax,%cr0 /* and let's page NOW! */ 285 286#ifdef BDE_DEBUGGER 287/* 288 * Complete the adjustments for paging so that we can keep tracing through 289 * initi386() after the low (physical) addresses for the gdt and idt become 290 * invalid. 291 */ 292 call bdb_commit_paging 293#endif 294 295 pushl $begin /* jump to high virtualized address */ 296 ret 297 298/* now running relocated at KERNBASE where the system is linked to run */ 299begin: 300 /* set up bootstrap stack */ 301 movl $_kstack+UPAGES*PAGE_SIZE,%esp /* bootstrap stack end location */ 302 xorl %eax,%eax /* mark end of frames */ 303 movl %eax,%ebp 304 movl _proc0paddr,%eax 305 movl _IdlePTD, %esi 306 movl %esi,PCB_CR3(%eax) 307 308 movl physfree, %esi 309 pushl %esi /* value of first for init386(first) */ 310 call _init386 /* wire 386 chip for unix operation */ 311 popl %esi 312 313 .globl __ucodesel,__udatasel 314 315 pushl $0 /* unused */ 316 pushl __udatasel /* ss */ 317 pushl $0 /* esp - filled in by execve() */ 318 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 319 pushl __ucodesel /* cs */ 320 pushl $0 /* eip - filled in by execve() */ 321 subl $(12*4),%esp /* space for rest of registers */ 322 323 pushl %esp /* call main with frame pointer */ 324 call _main /* autoconfiguration, mountroot etc */ 325 326 addl $(13*4),%esp /* back to a frame we can return with */ 327 328 /* 329 * now we've run main() and determined what cpu-type we are, we can 330 * enable write protection and alignment checking on i486 cpus and 331 * above. 332 */ 333#if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU) 334 cmpl $CPUCLASS_386,_cpu_class 335 je 1f 336 movl %cr0,%eax /* get control word */ 337 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 338 movl %eax,%cr0 /* and do it */ 3391: 340#endif 341 /* 342 * on return from main(), we are process 1 343 * set up address space and stack so that we can 'return' to user mode 344 */ 345 movl __ucodesel,%eax 346 movl __udatasel,%ecx 347 348 movl %cx,%ds 349 movl %cx,%es 350 movl %ax,%fs /* double map cs to fs */ 351 movl %cx,%gs /* and ds to gs */ 352 iret /* goto user! */ 353 354#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 355 356/* 357 * Signal trampoline, copied to top of user stack 358 */ 359NON_GPROF_ENTRY(sigcode) 360 call SIGF_HANDLER(%esp) 361 lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 362 /* copy at 8(%esp)) */ 363 pushl %eax 364 pushl %eax /* junk to fake return address */ 365 movl $SYS_sigreturn,%eax /* sigreturn() */ 366 LCALL(0x7,0) /* enter kernel with args on stack */ 367 hlt /* never gets here */ 368 .align 2,0x90 /* long word text-align */ 369_esigcode: 370 371 .data 372 .globl _szsigcode 373_szsigcode: 374 .long _esigcode-_sigcode 375 .text 376 377/********************************************************************** 378 * 379 * Recover the bootinfo passed to us from the boot program 380 * 381 */ 382recover_bootinfo: 383 /* 384 * This code is called in different ways depending on what loaded 385 * and started the kernel. This is used to detect how we get the 386 * arguments from the other code and what we do with them. 387 * 388 * Old disk boot blocks: 389 * (*btext)(howto, bootdev, cyloffset, esym); 390 * [return address == 0, and can NOT be returned to] 391 * [cyloffset was not supported by the FreeBSD boot code 392 * and always passed in as 0] 393 * [esym is also known as total in the boot code, and 394 * was never properly supported by the FreeBSD boot code] 395 * 396 * Old diskless netboot code: 397 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 398 * [return address != 0, and can NOT be returned to] 399 * If we are being booted by this code it will NOT work, 400 * so we are just going to halt if we find this case. 401 * 402 * New uniform boot code: 403 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 404 * [return address != 0, and can be returned to] 405 * 406 * There may seem to be a lot of wasted arguments in here, but 407 * that is so the newer boot code can still load very old kernels 408 * and old boot code can load new kernels. 409 */ 410 411 /* 412 * The old style disk boot blocks fake a frame on the stack and 413 * did an lret to get here. The frame on the stack has a return 414 * address of 0. 415 */ 416 cmpl $0,4(%ebp) 417 je olddiskboot 418 419 /* 420 * We have some form of return address, so this is either the 421 * old diskless netboot code, or the new uniform code. That can 422 * be detected by looking at the 5th argument, if it is 0 423 * we are being booted by the new uniform boot code. 424 */ 425 cmpl $0,24(%ebp) 426 je newboot 427 428 /* 429 * Seems we have been loaded by the old diskless boot code, we 430 * don't stand a chance of running as the diskless structure 431 * changed considerably between the two, so just halt. 432 */ 433 hlt 434 435 /* 436 * We have been loaded by the new uniform boot code. 437 * Let's check the bootinfo version, and if we do not understand 438 * it we return to the loader with a status of 1 to indicate this error 439 */ 440newboot: 441 movl 28(%ebp),%ebx /* &bootinfo.version */ 442 movl BI_VERSION(%ebx),%eax 443 cmpl $1,%eax /* We only understand version 1 */ 444 je 1f 445 movl $1,%eax /* Return status */ 446 leave 447 /* 448 * XXX this returns to our caller's caller (as is required) since 449 * we didn't set up a frame and our caller did. 450 */ 451 ret 452 4531: 454 /* 455 * If we have a kernelname copy it in 456 */ 457 movl BI_KERNELNAME(%ebx),%esi 458 cmpl $0,%esi 459 je 2f /* No kernelname */ 460 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 461 movl $R(_kernelname),%edi 462 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 463 je 1f 464 movb $'/',(%edi) 465 incl %edi 466 decl %ecx 4671: 468 cld 469 rep 470 movsb 471 4722: 473 /* 474 * Determine the size of the boot loader's copy of the bootinfo 475 * struct. This is impossible to do properly because old versions 476 * of the struct don't contain a size field and there are 2 old 477 * versions with the same version number. 478 */ 479 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 480 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 481 je got_bi_size /* no, sizeless version */ 482 movl BI_SIZE(%ebx),%ecx 483got_bi_size: 484 485 /* 486 * Copy the common part of the bootinfo struct 487 */ 488 movl %ebx,%esi 489 movl $R(_bootinfo),%edi 490 cmpl $BOOTINFO_SIZE,%ecx 491 jbe got_common_bi_size 492 movl $BOOTINFO_SIZE,%ecx 493got_common_bi_size: 494 cld 495 rep 496 movsb 497 498#ifdef NFS 499 /* 500 * If we have a nfs_diskless structure copy it in 501 */ 502 movl BI_NFS_DISKLESS(%ebx),%esi 503 cmpl $0,%esi 504 je olddiskboot 505 movl $R(_nfs_diskless),%edi 506 movl $NFSDISKLESS_SIZE,%ecx 507 cld 508 rep 509 movsb 510 movl $R(_nfs_diskless_valid),%edi 511 movl $1,(%edi) 512#endif 513 514 /* 515 * The old style disk boot. 516 * (*btext)(howto, bootdev, cyloffset, esym); 517 * Note that the newer boot code just falls into here to pick 518 * up howto and bootdev, cyloffset and esym are no longer used 519 */ 520olddiskboot: 521 movl 8(%ebp),%eax 522 movl %eax,R(_boothowto) 523 movl 12(%ebp),%eax 524 movl %eax,R(_bootdev) 525 526#if defined(USERCONFIG_BOOT) && defined(USERCONFIG) 527 movl $0x10200, %esi 528 movl $R(_userconfig_from_boot),%edi 529 movl $512,%ecx 530 cld 531 rep 532 movsb 533#endif /* USERCONFIG_BOOT */ 534 535 ret 536 537 538/********************************************************************** 539 * 540 * Identify the CPU and initialize anything special about it 541 * 542 */ 543identify_cpu: 544 545 /* Try to toggle alignment check flag; does not exist on 386. */ 546 pushfl 547 popl %eax 548 movl %eax,%ecx 549 orl $PSL_AC,%eax 550 pushl %eax 551 popfl 552 pushfl 553 popl %eax 554 xorl %ecx,%eax 555 andl $PSL_AC,%eax 556 pushl %ecx 557 popfl 558 559 testl %eax,%eax 560 jnz 1f 561 movl $CPU_386,R(_cpu) 562 jmp 3f 563 5641: /* Try to toggle identification flag; does not exist on early 486s. */ 565 pushfl 566 popl %eax 567 movl %eax,%ecx 568 xorl $PSL_ID,%eax 569 pushl %eax 570 popfl 571 pushfl 572 popl %eax 573 xorl %ecx,%eax 574 andl $PSL_ID,%eax 575 pushl %ecx 576 popfl 577 578 testl %eax,%eax 579 jnz 1f 580 movl $CPU_486,R(_cpu) 581 582 /* check for Cyrix 486DLC -- based on check routine */ 583 /* documented in "Cx486SLC/e SMM Programmer's Guide" */ 584 xorw %dx,%dx 585 cmpw %dx,%dx # set flags to known state 586 pushfw 587 popw %cx # store flags in ecx 588 movw $0xffff,%ax 589 movw $0x0004,%bx 590 divw %bx 591 pushfw 592 popw %ax 593 andw $0x08d5,%ax # mask off important bits 594 andw $0x08d5,%cx 595 cmpw %ax,%cx 596 597 jnz 3f # if flags changed, Intel chip 598 599 movl $CPU_486DLC,R(_cpu) # set CPU value for Cyrix 600 movl $0x69727943,R(_cpu_vendor) # store vendor string 601 movw $0x0078,R(_cpu_vendor+4) 602 603#ifndef CYRIX_CACHE_WORKS 604 /* Disable caching of the ISA hole only. */ 605 invd 606 movb $CCR0,%al # Configuration Register index (CCR0) 607 outb %al,$0x22 608 inb $0x23,%al 609 orb $(CCR0_NC1|CCR0_BARB),%al 610 movb %al,%ah 611 movb $CCR0,%al 612 outb %al,$0x22 613 movb %ah,%al 614 outb %al,$0x23 615 invd 616#else /* CYRIX_CACHE_WORKS */ 617 /* Set cache parameters */ 618 invd # Start with guaranteed clean cache 619 movb $CCR0,%al # Configuration Register index (CCR0) 620 outb %al,$0x22 621 inb $0x23,%al 622 andb $~CCR0_NC0,%al 623#ifndef CYRIX_CACHE_REALLY_WORKS 624 orb $(CCR0_NC1|CCR0_BARB),%al 625#else /* CYRIX_CACHE_REALLY_WORKS */ 626 orb $CCR0_NC1,%al 627#endif /* !CYRIX_CACHE_REALLY_WORKS */ 628 movb %al,%ah 629 movb $CCR0,%al 630 outb %al,$0x22 631 movb %ah,%al 632 outb %al,$0x23 633 /* clear non-cacheable region 1 */ 634 movb $(NCR1+2),%al 635 outb %al,$0x22 636 movb $NCR_SIZE_0K,%al 637 outb %al,$0x23 638 /* clear non-cacheable region 2 */ 639 movb $(NCR2+2),%al 640 outb %al,$0x22 641 movb $NCR_SIZE_0K,%al 642 outb %al,$0x23 643 /* clear non-cacheable region 3 */ 644 movb $(NCR3+2),%al 645 outb %al,$0x22 646 movb $NCR_SIZE_0K,%al 647 outb %al,$0x23 648 /* clear non-cacheable region 4 */ 649 movb $(NCR4+2),%al 650 outb %al,$0x22 651 movb $NCR_SIZE_0K,%al 652 outb %al,$0x23 653 /* enable caching in CR0 */ 654 movl %cr0,%eax 655 andl $~(CR0_CD|CR0_NW),%eax 656 movl %eax,%cr0 657 invd 658#endif /* !CYRIX_CACHE_WORKS */ 659 jmp 3f 660 6611: /* Use the `cpuid' instruction. */ 662 xorl %eax,%eax 663 .byte 0x0f,0xa2 # cpuid 0 664 movl %eax,R(_cpu_high) # highest capability 665 movl %ebx,R(_cpu_vendor) # store vendor string 666 movl %edx,R(_cpu_vendor+4) 667 movl %ecx,R(_cpu_vendor+8) 668 movb $0,R(_cpu_vendor+12) 669 670 movl $1,%eax 671 .byte 0x0f,0xa2 # cpuid 1 672 movl %eax,R(_cpu_id) # store cpu_id 673 movl %edx,R(_cpu_feature) # store cpu_feature 674 rorl $8,%eax # extract family type 675 andl $15,%eax 676 cmpl $5,%eax 677 jae 1f 678 679 /* less than Pentium; must be 486 */ 680 movl $CPU_486,R(_cpu) 681 jmp 3f 6821: 683 /* a Pentium? */ 684 cmpl $5,%eax 685 jne 2f 686 movl $CPU_586,R(_cpu) 687 jmp 3f 6882: 689 /* Greater than Pentium...call it a Pentium Pro */ 690 movl $CPU_686,R(_cpu) 6913: 692 ret 693 694 695/********************************************************************** 696 * 697 * Create the first page directory and its page tables. 698 * 699 */ 700 701create_pagetables: 702 703 testl $CPUID_PGE, R(_cpu_feature) 704 jz 1f 705 movl %cr4, %eax 706 orl $CR4_PGE, %eax 707 movl %eax, %cr4 7081: 709 710/* Find end of kernel image (rounded up to a page boundary). */ 711 movl $R(_end),%esi 712 713/* include symbols in "kernel image" if they are loaded and useful */ 714#ifdef DDB 715 movl R(_bootinfo+BI_ESYMTAB),%edi 716 testl %edi,%edi 717 je over_symalloc 718 movl %edi,%esi 719 movl $KERNBASE,%edi 720 addl %edi,R(_bootinfo+BI_SYMTAB) 721 addl %edi,R(_bootinfo+BI_ESYMTAB) 722over_symalloc: 723#endif 724 725 addl $PAGE_MASK,%esi 726 andl $~PAGE_MASK,%esi 727 movl %esi,R(_KERNend) /* save end of kernel */ 728 movl %esi,R(physfree) /* next free page is at end of kernel */ 729 730/* Allocate Kernel Page Tables */ 731 ALLOCPAGES(NKPT) 732 movl %esi,R(_KPTphys) 733 734/* Allocate Page Table Directory */ 735 ALLOCPAGES(1) 736 movl %esi,R(_IdlePTD) 737 738/* Allocate UPAGES */ 739 ALLOCPAGES(UPAGES) 740 movl %esi,R(p0upa) 741 addl $KERNBASE, %esi 742 movl %esi, R(_proc0paddr) 743 744/* Allocate proc0's page table for the UPAGES. */ 745 ALLOCPAGES(1) 746 movl %esi,R(p0upt) 747 748/* Map read-only from zero to the end of the kernel text section */ 749 xorl %eax, %eax 750#ifdef BDE_DEBUGGER 751/* If the debugger is present, actually map everything read-write. */ 752 cmpl $0,R(_bdb_exists) 753 jne map_read_write 754#endif 755 xorl %edx,%edx 756 testl $CPUID_PGE, R(_cpu_feature) 757 jz 2f 758 orl $PG_G,%edx 759 7602: movl $R(_etext),%ecx 761 addl $PAGE_MASK,%ecx 762 shrl $PAGE_SHIFT,%ecx 763 fillkptphys(%edx) 764 765/* Map read-write, data, bss and symbols */ 766 movl $R(_etext),%eax 767 addl $PAGE_MASK, %eax 768 andl $~PAGE_MASK, %eax 769map_read_write: 770 movl $PG_RW,%edx 771 testl $CPUID_PGE, R(_cpu_feature) 772 jz 1f 773 orl $PG_G,%edx 774 7751: movl R(_KERNend),%ecx 776 subl %eax,%ecx 777 shrl $PAGE_SHIFT,%ecx 778 fillkptphys(%edx) 779 780/* Map page directory. */ 781 movl R(_IdlePTD), %eax 782 movl $1, %ecx 783 fillkptphys($PG_RW) 784 785/* Map proc0's page table for the UPAGES. */ 786 movl R(p0upt), %eax 787 movl $1, %ecx 788 fillkptphys($PG_RW) 789 790/* Map proc0's UPAGES in the physical way ... */ 791 movl R(p0upa), %eax 792 movl $UPAGES, %ecx 793 fillkptphys($PG_RW) 794 795/* Map ISA hole */ 796 movl $ISA_HOLE_START, %eax 797 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 798 fillkptphys($PG_RW) 799 800/* Map proc0s UPAGES in the special page table for this purpose ... */ 801 movl R(p0upa), %eax 802 movl $KSTKPTEOFF, %ebx 803 movl $UPAGES, %ecx 804 fillkpt(R(p0upt), $PG_RW) 805 806/* ... and put the page table in the pde. */ 807 movl R(p0upt), %eax 808 movl $KSTKPTDI, %ebx 809 movl $1, %ecx 810 fillkpt(R(_IdlePTD), $PG_RW) 811 812/* install a pde for temporary double map of bottom of VA */ 813 movl R(_KPTphys), %eax 814 xorl %ebx, %ebx 815 movl $1, %ecx 816 fillkpt(R(_IdlePTD), $PG_RW) 817 818/* install pde's for pt's */ 819 movl R(_KPTphys), %eax 820 movl $KPTDI, %ebx 821 movl $NKPT, %ecx 822 fillkpt(R(_IdlePTD), $PG_RW) 823 824/* install a pde recursively mapping page directory as a page table */ 825 movl R(_IdlePTD), %eax 826 movl $PTDPTDI, %ebx 827 movl $1,%ecx 828 fillkpt(R(_IdlePTD), $PG_RW) 829 830 ret 831 832#ifdef BDE_DEBUGGER 833bdb_prepare_paging: 834 cmpl $0,R(_bdb_exists) 835 je bdb_prepare_paging_exit 836 837 subl $6,%esp 838 839 /* 840 * Copy and convert debugger entries from the bootstrap gdt and idt 841 * to the kernel gdt and idt. Everything is still in low memory. 842 * Tracing continues to work after paging is enabled because the 843 * low memory addresses remain valid until everything is relocated. 844 * However, tracing through the setidt() that initializes the trace 845 * trap will crash. 846 */ 847 sgdt (%esp) 848 movl 2(%esp),%esi /* base address of bootstrap gdt */ 849 movl $R(_gdt),%edi 850 movl %edi,2(%esp) /* prepare to load kernel gdt */ 851 movl $8*18/4,%ecx 852 cld 853 rep /* copy gdt */ 854 movsl 855 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 856 movb $0x92,-8+5(%edi) 857 lgdt (%esp) 858 859 sidt (%esp) 860 movl 2(%esp),%esi /* base address of current idt */ 861 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 862 movw 8(%esi),%ax 863 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 864 movl 8+2(%esi),%eax 865 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 866 movl 24+4(%esi),%eax /* same for bpt descriptor */ 867 movw 24(%esi),%ax 868 movl %eax,R(bdb_bpt_ljmp+1) 869 movl 24+2(%esi),%eax 870 movw %ax,R(bdb_bpt_ljmp+5) 871 movl $R(_idt),%edi 872 movl %edi,2(%esp) /* prepare to load kernel idt */ 873 movl $8*4/4,%ecx 874 cld 875 rep /* copy idt */ 876 movsl 877 lidt (%esp) 878 879 addl $6,%esp 880 881bdb_prepare_paging_exit: 882 ret 883 884/* Relocate debugger gdt entries and gdt and idt pointers. */ 885bdb_commit_paging: 886 cmpl $0,_bdb_exists 887 je bdb_commit_paging_exit 888 889 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 890 movl $9,%ecx 891reloc_gdt: 892 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 893 addl $8,%eax /* now KERNBASE>>24 */ 894 loop reloc_gdt 895 896 subl $6,%esp 897 sgdt (%esp) 898 addl $KERNBASE,2(%esp) 899 lgdt (%esp) 900 sidt (%esp) 901 addl $KERNBASE,2(%esp) 902 lidt (%esp) 903 addl $6,%esp 904 905 int $3 906 907bdb_commit_paging_exit: 908 ret 909 910#endif /* BDE_DEBUGGER */ 911