locore.s revision 37272
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 1.109 1998/06/21 18:02:34 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_bootp.h" 48#include "opt_ddb.h" 49#include "opt_nfsroot.h" 50#include "opt_userconfig.h" 51#include "opt_vm86.h" 52 53#include <sys/syscall.h> 54#include <sys/reboot.h> 55 56#include <machine/asmacros.h> 57#include <machine/cputypes.h> 58#include <machine/psl.h> 59#include <machine/pmap.h> 60#include <machine/specialreg.h> 61 62#include "assym.s" 63 64/* 65 * XXX 66 * 67 * Note: This version greatly munged to avoid various assembler errors 68 * that may be fixed in newer versions of gas. Perhaps newer versions 69 * will have more pleasant appearance. 70 */ 71 72/* 73 * PTmap is recursive pagemap at top of virtual address space. 74 * Within PTmap, the page directory can be found (third indirection). 75 */ 76 .globl _PTmap,_PTD,_PTDpde 77 .set _PTmap,(PTDPTDI << PDRSHIFT) 78 .set _PTD,_PTmap + (PTDPTDI * PAGE_SIZE) 79 .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 80 81/* 82 * APTmap, APTD is the alternate recursive pagemap. 83 * It's used when modifying another process's page tables. 84 */ 85 .globl _APTmap,_APTD,_APTDpde 86 .set _APTmap,APTDPTDI << PDRSHIFT 87 .set _APTD,_APTmap + (APTDPTDI * PAGE_SIZE) 88 .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 89 90/* 91 * Globals 92 */ 93 .data 94 ALIGN_DATA /* just to be sure */ 95 96 .globl HIDENAME(tmpstk) 97 .space 0x2000 /* space for tmpstk - temporary stack */ 98HIDENAME(tmpstk): 99 100 .globl _boothowto,_bootdev 101 102 .globl _cpu,_cpu_vendor,_cpu_id,_bootinfo 103 .globl _cpu_high, _cpu_feature 104 105_cpu: .long 0 /* are we 386, 386sx, or 486 */ 106_cpu_id: .long 0 /* stepping ID */ 107_cpu_high: .long 0 /* highest arg to CPUID */ 108_cpu_feature: .long 0 /* features */ 109_cpu_vendor: .space 20 /* CPU origin code */ 110_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 111 112_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 113physfree: .long 0 /* phys addr of next free page */ 114 115#ifdef SMP 116cpu0pp: .long 0 /* phys addr cpu0 private pg */ 117cpu0pt: .long 0 /* phys addr cpu0 private pt */ 118 119 .globl _cpu0prvpage,_cpu0prvpt 120_cpu0prvpage: .long 0 /* relocated version */ 121_cpu0prvpt: .long 0 /* relocated version */ 122#endif /* SMP */ 123 124 .globl _IdlePTD 125_IdlePTD: .long 0 /* phys addr of kernel PTD */ 126 127#ifdef SMP 128 .globl _KPTphys 129#endif 130_KPTphys: .long 0 /* phys addr of kernel page tables */ 131 132 .globl _proc0paddr 133_proc0paddr: .long 0 /* address of proc 0 address space */ 134p0upa: .long 0 /* phys addr of proc0's UPAGES */ 135 136#ifdef VM86 137 .globl _vm86paddr, _vm86pa 138_vm86paddr: .long 0 /* address of vm86 region */ 139_vm86pa: .long 0 /* phys addr of vm86 region */ 140#endif 141 142#ifdef BDE_DEBUGGER 143 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 144_bdb_exists: .long 0 145#endif 146 147 148/********************************************************************** 149 * 150 * Some handy macros 151 * 152 */ 153 154#define R(foo) ((foo)-KERNBASE) 155 156#define ALLOCPAGES(foo) \ 157 movl R(physfree), %esi ; \ 158 movl $((foo)*PAGE_SIZE), %eax ; \ 159 addl %esi, %eax ; \ 160 movl %eax, R(physfree) ; \ 161 movl %esi, %edi ; \ 162 movl $((foo)*PAGE_SIZE),%ecx ; \ 163 xorl %eax,%eax ; \ 164 cld ; \ 165 rep ; \ 166 stosb 167 168/* 169 * fillkpt 170 * eax = page frame address 171 * ebx = index into page table 172 * ecx = how many pages to map 173 * base = base address of page dir/table 174 * prot = protection bits 175 */ 176#define fillkpt(base, prot) \ 177 shll $2,%ebx ; \ 178 addl base,%ebx ; \ 179 orl $PG_V,%eax ; \ 180 orl prot,%eax ; \ 1811: movl %eax,(%ebx) ; \ 182 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 183 addl $4,%ebx ; /* next pte */ \ 184 loop 1b 185 186/* 187 * fillkptphys(prot) 188 * eax = physical address 189 * ecx = how many pages to map 190 * prot = protection bits 191 */ 192#define fillkptphys(prot) \ 193 movl %eax, %ebx ; \ 194 shrl $PAGE_SHIFT, %ebx ; \ 195 fillkpt(R(_KPTphys), prot) 196 197 .text 198/********************************************************************** 199 * 200 * This is where the bootblocks start us, set the ball rolling... 201 * 202 */ 203NON_GPROF_ENTRY(btext) 204 205#ifdef PC98 206 jmp 1f 207 .globl _pc98_system_parameter 208 .org 0x400 209_pc98_system_parameter: 210 .space 0x240 /* BIOS parameter block */ 2111: 212 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 213 movl $0xa1000,%esi 214 movl $0x100000,%edi 215 movl $0x0630,%ecx 216 cld 217 rep 218 movsb 219#else /* IBM-PC */ 220#ifdef BDE_DEBUGGER 221#ifdef BIOS_STEALS_3K 222 cmpl $0x0375c339,0x95504 223#else 224 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 225#endif 226 jne 1f 227 movb $1,R(_bdb_exists) 2281: 229#endif 230 231/* Tell the bios to warmboot next time */ 232 movw $0x1234,0x472 233#endif /* PC98 */ 234 235/* Set up a real frame in case the double return in newboot is executed. */ 236 pushl %ebp 237 movl %esp, %ebp 238 239/* Don't trust what the BIOS gives for eflags. */ 240 pushl $PSL_KERNEL 241 popfl 242 243/* 244 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 245 * to set %cs, %ds, %es and %ss. 246 */ 247 mov %ds, %ax 248 mov %ax, %fs 249 mov %ax, %gs 250 251 call recover_bootinfo 252 253/* Get onto a stack that we can trust. */ 254/* 255 * XXX this step is delayed in case recover_bootinfo needs to return via 256 * the old stack, but it need not be, since recover_bootinfo actually 257 * returns via the old frame. 258 */ 259 movl $R(HIDENAME(tmpstk)),%esp 260 261#ifdef PC98 262 testb $0x02,0x100620 /* pc98_machine_type & M_EPSON_PC98 */ 263 jz 3f 264 cmpb $0x0b,0x100624 /* epson_machine_id <= 0x0b */ 265 ja 3f 266 267 /* count up memory */ 268 movl $0x100000,%eax /* next, talley remaining memory */ 269 movl $0xFFF-0x100,%ecx 2701: movl 0(%eax),%ebx /* save location to check */ 271 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 272 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 273 jne 2f 274 movl %ebx,0(%eax) /* restore memory */ 275 addl $PAGE_SIZE,%eax 276 loop 1b 2772: subl $0x100000,%eax 278 shrl $17,%eax 279 movb %al,0x100401 2803: 281#endif 282 283 call identify_cpu 284 285/* clear bss */ 286/* 287 * XXX this should be done a little earlier. 288 * 289 * XXX we don't check that there is memory for our bss and page tables 290 * before using it. 291 * 292 * XXX the boot program somewhat bogusly clears the bss. We still have 293 * to do it in case we were unzipped by kzipboot. Then the boot program 294 * only clears kzipboot's bss. 295 * 296 * XXX the gdt and idt are still somewhere in the boot program. We 297 * depend on the convention that the boot program is below 1MB and we 298 * are above 1MB to keep the gdt and idt away from the bss and page 299 * tables. The idt is only used if BDE_DEBUGGER is enabled. 300 */ 301 movl $R(_end),%ecx 302 movl $R(_edata),%edi 303 subl %edi,%ecx 304 xorl %eax,%eax 305 cld 306 rep 307 stosb 308 309#if NAPM > 0 310#ifndef VM86 311/* 312 * XXX it's not clear that APM can live in the current environonment. 313 * Only pc-relative addressing works. 314 */ 315 call _apm_setup 316#endif 317#endif 318 319 call create_pagetables 320 321#ifdef VM86 322/* 323 * If the CPU has support for VME, turn it on. 324 */ 325 testl $CPUID_VME, R(_cpu_feature) 326 jz 1f 327 movl %cr4, %eax 328 orl $CR4_VME, %eax 329 movl %eax, %cr4 3301: 331#endif /* VM86 */ 332 333#ifdef BDE_DEBUGGER 334/* 335 * Adjust as much as possible for paging before enabling paging so that the 336 * adjustments can be traced. 337 */ 338 call bdb_prepare_paging 339#endif 340 341/* Now enable paging */ 342 movl R(_IdlePTD), %eax 343 movl %eax,%cr3 /* load ptd addr into mmu */ 344 movl %cr0,%eax /* get control word */ 345 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 346 movl %eax,%cr0 /* and let's page NOW! */ 347 348#ifdef BDE_DEBUGGER 349/* 350 * Complete the adjustments for paging so that we can keep tracing through 351 * initi386() after the low (physical) addresses for the gdt and idt become 352 * invalid. 353 */ 354 call bdb_commit_paging 355#endif 356 357 pushl $begin /* jump to high virtualized address */ 358 ret 359 360/* now running relocated at KERNBASE where the system is linked to run */ 361begin: 362 /* set up bootstrap stack */ 363 movl _proc0paddr,%esp /* location of in-kernel pages */ 364 addl $UPAGES*PAGE_SIZE,%esp /* bootstrap stack end location */ 365 xorl %eax,%eax /* mark end of frames */ 366 movl %eax,%ebp 367 movl _proc0paddr,%eax 368 movl _IdlePTD, %esi 369 movl %esi,PCB_CR3(%eax) 370 movl $_proc0,_curproc 371 372 movl physfree, %esi 373 pushl %esi /* value of first for init386(first) */ 374 call _init386 /* wire 386 chip for unix operation */ 375 popl %esi 376 377 .globl __ucodesel,__udatasel 378 379 pushl $0 /* unused */ 380 pushl __udatasel /* ss */ 381 pushl $0 /* esp - filled in by execve() */ 382 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 383 pushl __ucodesel /* cs */ 384 pushl $0 /* eip - filled in by execve() */ 385 subl $(12*4),%esp /* space for rest of registers */ 386 387 pushl %esp /* call main with frame pointer */ 388 call _main /* autoconfiguration, mountroot etc */ 389 390 hlt /* never returns to here */ 391 392/* 393 * When starting init, call this to configure the process for user 394 * mode. This will be inherited by other processes. 395 */ 396NON_GPROF_ENTRY(prepare_usermode) 397 /* 398 * Now we've run main() and determined what cpu-type we are, we can 399 * enable write protection and alignment checking on i486 cpus and 400 * above. 401 */ 402#if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU) 403 cmpl $CPUCLASS_386,_cpu_class 404 je 1f 405 movl %cr0,%eax /* get control word */ 406 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 407 movl %eax,%cr0 /* and do it */ 4081: 409#endif 410 /* 411 * on return from main(), we are process 1 412 * set up address space and stack so that we can 'return' to user mode 413 */ 414 movl __ucodesel,%eax 415 movl __udatasel,%ecx 416 417#if 0 418 movl %cx,%ds 419#endif 420 movl %cx,%es 421 movl %ax,%fs /* double map cs to fs */ 422 movl %cx,%gs /* and ds to gs */ 423 ret /* goto user! */ 424 425 426#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 427 428/* 429 * Signal trampoline, copied to top of user stack 430 */ 431NON_GPROF_ENTRY(sigcode) 432 call SIGF_HANDLER(%esp) 433 lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 434 /* copy at 8(%esp)) */ 435 pushl %eax 436 pushl %eax /* junk to fake return address */ 437 movl $SYS_sigreturn,%eax /* sigreturn() */ 438 LCALL(0x7,0) /* enter kernel with args on stack */ 439 hlt /* never gets here */ 440 ALIGN_TEXT 441_esigcode: 442 443 .data 444 .globl _szsigcode 445_szsigcode: 446 .long _esigcode-_sigcode 447 .text 448 449/********************************************************************** 450 * 451 * Recover the bootinfo passed to us from the boot program 452 * 453 */ 454recover_bootinfo: 455 /* 456 * This code is called in different ways depending on what loaded 457 * and started the kernel. This is used to detect how we get the 458 * arguments from the other code and what we do with them. 459 * 460 * Old disk boot blocks: 461 * (*btext)(howto, bootdev, cyloffset, esym); 462 * [return address == 0, and can NOT be returned to] 463 * [cyloffset was not supported by the FreeBSD boot code 464 * and always passed in as 0] 465 * [esym is also known as total in the boot code, and 466 * was never properly supported by the FreeBSD boot code] 467 * 468 * Old diskless netboot code: 469 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 470 * [return address != 0, and can NOT be returned to] 471 * If we are being booted by this code it will NOT work, 472 * so we are just going to halt if we find this case. 473 * 474 * New uniform boot code: 475 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 476 * [return address != 0, and can be returned to] 477 * 478 * There may seem to be a lot of wasted arguments in here, but 479 * that is so the newer boot code can still load very old kernels 480 * and old boot code can load new kernels. 481 */ 482 483 /* 484 * The old style disk boot blocks fake a frame on the stack and 485 * did an lret to get here. The frame on the stack has a return 486 * address of 0. 487 */ 488 cmpl $0,4(%ebp) 489 je olddiskboot 490 491 /* 492 * We have some form of return address, so this is either the 493 * old diskless netboot code, or the new uniform code. That can 494 * be detected by looking at the 5th argument, if it is 0 495 * we are being booted by the new uniform boot code. 496 */ 497 cmpl $0,24(%ebp) 498 je newboot 499 500 /* 501 * Seems we have been loaded by the old diskless boot code, we 502 * don't stand a chance of running as the diskless structure 503 * changed considerably between the two, so just halt. 504 */ 505 hlt 506 507 /* 508 * We have been loaded by the new uniform boot code. 509 * Let's check the bootinfo version, and if we do not understand 510 * it we return to the loader with a status of 1 to indicate this error 511 */ 512newboot: 513 movl 28(%ebp),%ebx /* &bootinfo.version */ 514 movl BI_VERSION(%ebx),%eax 515 cmpl $1,%eax /* We only understand version 1 */ 516 je 1f 517 movl $1,%eax /* Return status */ 518 leave 519 /* 520 * XXX this returns to our caller's caller (as is required) since 521 * we didn't set up a frame and our caller did. 522 */ 523 ret 524 5251: 526 /* 527 * If we have a kernelname copy it in 528 */ 529 movl BI_KERNELNAME(%ebx),%esi 530 cmpl $0,%esi 531 je 2f /* No kernelname */ 532 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 533 movl $R(_kernelname),%edi 534 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 535 je 1f 536 movb $'/',(%edi) 537 incl %edi 538 decl %ecx 5391: 540 cld 541 rep 542 movsb 543 5442: 545 /* 546 * Determine the size of the boot loader's copy of the bootinfo 547 * struct. This is impossible to do properly because old versions 548 * of the struct don't contain a size field and there are 2 old 549 * versions with the same version number. 550 */ 551 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 552 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 553 je got_bi_size /* no, sizeless version */ 554 movl BI_SIZE(%ebx),%ecx 555got_bi_size: 556 557 /* 558 * Copy the common part of the bootinfo struct 559 */ 560 movl %ebx,%esi 561 movl $R(_bootinfo),%edi 562 cmpl $BOOTINFO_SIZE,%ecx 563 jbe got_common_bi_size 564 movl $BOOTINFO_SIZE,%ecx 565got_common_bi_size: 566 cld 567 rep 568 movsb 569 570#ifdef NFS 571#ifndef BOOTP_NFSV3 572 /* 573 * If we have a nfs_diskless structure copy it in 574 */ 575 movl BI_NFS_DISKLESS(%ebx),%esi 576 cmpl $0,%esi 577 je olddiskboot 578 movl $R(_nfs_diskless),%edi 579 movl $NFSDISKLESS_SIZE,%ecx 580 cld 581 rep 582 movsb 583 movl $R(_nfs_diskless_valid),%edi 584 movl $1,(%edi) 585#endif 586#endif 587 588 /* 589 * The old style disk boot. 590 * (*btext)(howto, bootdev, cyloffset, esym); 591 * Note that the newer boot code just falls into here to pick 592 * up howto and bootdev, cyloffset and esym are no longer used 593 */ 594olddiskboot: 595 movl 8(%ebp),%eax 596 movl %eax,R(_boothowto) 597 movl 12(%ebp),%eax 598 movl %eax,R(_bootdev) 599 600#if defined(USERCONFIG_BOOT) && defined(USERCONFIG) 601 movl $0x10200, %esi 602 movl $R(_userconfig_from_boot),%edi 603 movl $512,%ecx 604 cld 605 rep 606 movsb 607#endif /* USERCONFIG_BOOT */ 608 609 ret 610 611 612/********************************************************************** 613 * 614 * Identify the CPU and initialize anything special about it 615 * 616 */ 617identify_cpu: 618 619 /* Try to toggle alignment check flag; does not exist on 386. */ 620 pushfl 621 popl %eax 622 movl %eax,%ecx 623 orl $PSL_AC,%eax 624 pushl %eax 625 popfl 626 pushfl 627 popl %eax 628 xorl %ecx,%eax 629 andl $PSL_AC,%eax 630 pushl %ecx 631 popfl 632 633 testl %eax,%eax 634 jnz try486 635 636 /* NexGen CPU does not have aligment check flag. */ 637 pushfl 638 movl $0x5555, %eax 639 xorl %edx, %edx 640 movl $2, %ecx 641 clc 642 divl %ecx 643 jz trynexgen 644 popfl 645 movl $CPU_386,R(_cpu) 646 jmp 3f 647 648trynexgen: 649 popfl 650 movl $CPU_NX586,R(_cpu) 651 movl $0x4778654e,R(_cpu_vendor) # store vendor string 652 movl $0x72446e65,R(_cpu_vendor+4) 653 movl $0x6e657669,R(_cpu_vendor+8) 654 movl $0,R(_cpu_vendor+12) 655 jmp 3f 656 657try486: /* Try to toggle identification flag; does not exist on early 486s. */ 658 pushfl 659 popl %eax 660 movl %eax,%ecx 661 xorl $PSL_ID,%eax 662 pushl %eax 663 popfl 664 pushfl 665 popl %eax 666 xorl %ecx,%eax 667 andl $PSL_ID,%eax 668 pushl %ecx 669 popfl 670 671 testl %eax,%eax 672 jnz trycpuid 673 movl $CPU_486,R(_cpu) 674 675 /* 676 * Check Cyrix CPU 677 * Cyrix CPUs do not change the undefined flags following 678 * execution of the divide instruction which divides 5 by 2. 679 * 680 * Note: CPUID is enabled on M2, so it passes another way. 681 */ 682 pushfl 683 movl $0x5555, %eax 684 xorl %edx, %edx 685 movl $2, %ecx 686 clc 687 divl %ecx 688 jnc trycyrix 689 popfl 690 jmp 3f /* You may use Intel CPU. */ 691 692trycyrix: 693 popfl 694 /* 695 * IBM Bluelighting CPU also doesn't change the undefined flags. 696 * Because IBM doesn't disclose the information for Bluelighting 697 * CPU, we couldn't distinguish it from Cyrix's (including IBM 698 * brand of Cyrix CPUs). 699 */ 700 movl $0x69727943,R(_cpu_vendor) # store vendor string 701 movl $0x736e4978,R(_cpu_vendor+4) 702 movl $0x64616574,R(_cpu_vendor+8) 703 jmp 3f 704 705trycpuid: /* Use the `cpuid' instruction. */ 706 xorl %eax,%eax 707 .byte 0x0f,0xa2 # cpuid 0 708 movl %eax,R(_cpu_high) # highest capability 709 movl %ebx,R(_cpu_vendor) # store vendor string 710 movl %edx,R(_cpu_vendor+4) 711 movl %ecx,R(_cpu_vendor+8) 712 movb $0,R(_cpu_vendor+12) 713 714 movl $1,%eax 715 .byte 0x0f,0xa2 # cpuid 1 716 movl %eax,R(_cpu_id) # store cpu_id 717 movl %edx,R(_cpu_feature) # store cpu_feature 718 rorl $8,%eax # extract family type 719 andl $15,%eax 720 cmpl $5,%eax 721 jae 1f 722 723 /* less than Pentium; must be 486 */ 724 movl $CPU_486,R(_cpu) 725 jmp 3f 7261: 727 /* a Pentium? */ 728 cmpl $5,%eax 729 jne 2f 730 movl $CPU_586,R(_cpu) 731 jmp 3f 7322: 733 /* Greater than Pentium...call it a Pentium Pro */ 734 movl $CPU_686,R(_cpu) 7353: 736 ret 737 738 739/********************************************************************** 740 * 741 * Create the first page directory and its page tables. 742 * 743 */ 744 745create_pagetables: 746 747 testl $CPUID_PGE, R(_cpu_feature) 748 jz 1f 749 movl %cr4, %eax 750 orl $CR4_PGE, %eax 751 movl %eax, %cr4 7521: 753 754/* Find end of kernel image (rounded up to a page boundary). */ 755 movl $R(_end),%esi 756 757/* include symbols in "kernel image" if they are loaded and useful */ 758#ifdef DDB 759 movl R(_bootinfo+BI_ESYMTAB),%edi 760 testl %edi,%edi 761 je over_symalloc 762 movl %edi,%esi 763 movl $KERNBASE,%edi 764 addl %edi,R(_bootinfo+BI_SYMTAB) 765 addl %edi,R(_bootinfo+BI_ESYMTAB) 766over_symalloc: 767#endif 768 769 addl $PAGE_MASK,%esi 770 andl $~PAGE_MASK,%esi 771 movl %esi,R(_KERNend) /* save end of kernel */ 772 movl %esi,R(physfree) /* next free page is at end of kernel */ 773 774/* Allocate Kernel Page Tables */ 775 ALLOCPAGES(NKPT) 776 movl %esi,R(_KPTphys) 777 778/* Allocate Page Table Directory */ 779 ALLOCPAGES(1) 780 movl %esi,R(_IdlePTD) 781 782/* Allocate UPAGES */ 783 ALLOCPAGES(UPAGES) 784 movl %esi,R(p0upa) 785 addl $KERNBASE, %esi 786 movl %esi, R(_proc0paddr) 787 788#ifdef VM86 789 ALLOCPAGES(4) /* IOPAGES + ext + stack */ 790 movl %esi,R(_vm86pa) 791 addl $KERNBASE, %esi 792 movl %esi, R(_vm86paddr) 793#endif /* VM86 */ 794 795#ifdef SMP 796/* Allocate cpu0's private data page */ 797 ALLOCPAGES(1) 798 movl %esi,R(cpu0pp) 799 addl $KERNBASE, %esi 800 movl %esi, R(_cpu0prvpage) /* relocated to KVM space */ 801 802/* Allocate cpu0's private page table for mapping priv page, apic, etc */ 803 ALLOCPAGES(1) 804 movl %esi,R(cpu0pt) 805 addl $KERNBASE, %esi 806 movl %esi, R(_cpu0prvpt) /* relocated to KVM space */ 807#endif /* SMP */ 808 809/* Map read-only from zero to the end of the kernel text section */ 810 xorl %eax, %eax 811#ifdef BDE_DEBUGGER 812/* If the debugger is present, actually map everything read-write. */ 813 cmpl $0,R(_bdb_exists) 814 jne map_read_write 815#endif 816 xorl %edx,%edx 817 818#if !defined(SMP) 819 testl $CPUID_PGE, R(_cpu_feature) 820 jz 2f 821 orl $PG_G,%edx 822#endif 823 8242: movl $R(_etext),%ecx 825 addl $PAGE_MASK,%ecx 826 shrl $PAGE_SHIFT,%ecx 827 fillkptphys(%edx) 828 829/* Map read-write, data, bss and symbols */ 830 movl $R(_etext),%eax 831 addl $PAGE_MASK, %eax 832 andl $~PAGE_MASK, %eax 833map_read_write: 834 movl $PG_RW,%edx 835#if !defined(SMP) 836 testl $CPUID_PGE, R(_cpu_feature) 837 jz 1f 838 orl $PG_G,%edx 839#endif 840 8411: movl R(_KERNend),%ecx 842 subl %eax,%ecx 843 shrl $PAGE_SHIFT,%ecx 844 fillkptphys(%edx) 845 846/* Map page directory. */ 847 movl R(_IdlePTD), %eax 848 movl $1, %ecx 849 fillkptphys($PG_RW) 850 851/* Map proc0's UPAGES in the physical way ... */ 852 movl R(p0upa), %eax 853 movl $UPAGES, %ecx 854 fillkptphys($PG_RW) 855 856/* Map ISA hole */ 857 movl $ISA_HOLE_START, %eax 858 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 859 fillkptphys($PG_RW) 860 861#ifdef VM86 862/* Map space for the vm86 region */ 863 movl R(_vm86pa), %eax 864 movl $4, %ecx 865 fillkptphys($PG_RW) 866 867/* Map page 0 into the vm86 page table */ 868 movl $0, %eax 869 movl $0, %ebx 870 movl $1, %ecx 871 fillkpt(R(_vm86pa), $PG_RW|PG_U) 872 873/* ...likewise for the ISA hole */ 874 movl $ISA_HOLE_START, %eax 875 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 876 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 877 fillkpt(R(_vm86pa), $PG_RW|PG_U) 878#endif /* VM86 */ 879 880#ifdef SMP 881/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 882 movl R(cpu0pp), %eax 883 movl $1, %ecx 884 fillkptphys($PG_RW) 885 886/* Map cpu0's private page table into global kmem FWIW */ 887 movl R(cpu0pt), %eax 888 movl $1, %ecx 889 fillkptphys($PG_RW) 890 891/* Map the private page into the private page table into private space */ 892 movl R(cpu0pp), %eax 893 movl $0, %ebx /* pte offset = 0 */ 894 movl $1, %ecx /* one private page coming right up */ 895 fillkpt(R(cpu0pt), $PG_RW) 896 897/* Map the page table page into private space */ 898 movl R(cpu0pt), %eax 899 movl $1, %ebx /* pte offset = 1 */ 900 movl $1, %ecx /* one private pt coming right up */ 901 fillkpt(R(cpu0pt), $PG_RW) 902 903/* ... and put the page table table in the pde. */ 904 movl R(cpu0pt), %eax 905 movl $MPPTDI, %ebx 906 movl $1, %ecx 907 fillkpt(R(_IdlePTD), $PG_RW) 908 909/* Fakeup VA for the local apic to allow early traps. */ 910 ALLOCPAGES(1) 911 movl %esi, %eax 912 movl $2, %ebx /* pte offset = 2 */ 913 movl $1, %ecx /* one private pt coming right up */ 914 fillkpt(R(cpu0pt), $PG_RW) 915 916/* Initialize mp lock to allow early traps */ 917 movl $1, R(_mp_lock) 918 919/* Initialize my_idlePTD to IdlePTD */ 920 movl R(cpu0pp), %eax 921 movl R(_IdlePTD), %ecx 922 movl %ecx,GD_MY_IDLEPTD(%eax) 923 924#endif /* SMP */ 925 926/* install a pde for temporary double map of bottom of VA */ 927 movl R(_KPTphys), %eax 928 xorl %ebx, %ebx 929 movl $1, %ecx 930 fillkpt(R(_IdlePTD), $PG_RW) 931 932/* install pde's for pt's */ 933 movl R(_KPTphys), %eax 934 movl $KPTDI, %ebx 935 movl $NKPT, %ecx 936 fillkpt(R(_IdlePTD), $PG_RW) 937 938/* install a pde recursively mapping page directory as a page table */ 939 movl R(_IdlePTD), %eax 940 movl $PTDPTDI, %ebx 941 movl $1,%ecx 942 fillkpt(R(_IdlePTD), $PG_RW) 943 944 ret 945 946#ifdef BDE_DEBUGGER 947bdb_prepare_paging: 948 cmpl $0,R(_bdb_exists) 949 je bdb_prepare_paging_exit 950 951 subl $6,%esp 952 953 /* 954 * Copy and convert debugger entries from the bootstrap gdt and idt 955 * to the kernel gdt and idt. Everything is still in low memory. 956 * Tracing continues to work after paging is enabled because the 957 * low memory addresses remain valid until everything is relocated. 958 * However, tracing through the setidt() that initializes the trace 959 * trap will crash. 960 */ 961 sgdt (%esp) 962 movl 2(%esp),%esi /* base address of bootstrap gdt */ 963 movl $R(_gdt),%edi 964 movl %edi,2(%esp) /* prepare to load kernel gdt */ 965 movl $8*18/4,%ecx 966 cld 967 rep /* copy gdt */ 968 movsl 969 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 970 movb $0x92,-8+5(%edi) 971 lgdt (%esp) 972 973 sidt (%esp) 974 movl 2(%esp),%esi /* base address of current idt */ 975 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 976 movw 8(%esi),%ax 977 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 978 movl 8+2(%esi),%eax 979 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 980 movl 24+4(%esi),%eax /* same for bpt descriptor */ 981 movw 24(%esi),%ax 982 movl %eax,R(bdb_bpt_ljmp+1) 983 movl 24+2(%esi),%eax 984 movw %ax,R(bdb_bpt_ljmp+5) 985 movl $R(_idt),%edi 986 movl %edi,2(%esp) /* prepare to load kernel idt */ 987 movl $8*4/4,%ecx 988 cld 989 rep /* copy idt */ 990 movsl 991 lidt (%esp) 992 993 addl $6,%esp 994 995bdb_prepare_paging_exit: 996 ret 997 998/* Relocate debugger gdt entries and gdt and idt pointers. */ 999bdb_commit_paging: 1000 cmpl $0,_bdb_exists 1001 je bdb_commit_paging_exit 1002 1003 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 1004 movl $9,%ecx 1005reloc_gdt: 1006 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 1007 addl $8,%eax /* now KERNBASE>>24 */ 1008 loop reloc_gdt 1009 1010 subl $6,%esp 1011 sgdt (%esp) 1012 addl $KERNBASE,2(%esp) 1013 lgdt (%esp) 1014 sidt (%esp) 1015 addl $KERNBASE,2(%esp) 1016 lidt (%esp) 1017 addl $6,%esp 1018 1019 int $3 1020 1021bdb_commit_paging_exit: 1022 ret 1023 1024#endif /* BDE_DEBUGGER */ 1025