locore.s revision 29663
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 1.98 1997/09/21 05:49:56 dyson 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/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#ifdef SMP 89 .globl _SMP_prvstart 90 .set _SMP_prvstart,(MPPTDI << PDRSHIFT) 91 92 .globl _SMP_prvpage,_SMP_prvpt,_lapic,_SMP_ioapic 93 .globl _prv_CPAGE1,_prv_CPAGE2,_prv_CPAGE3 94 .globl _idlestack,_idlestack_top 95 .set _SMP_prvpage,_SMP_prvstart 96 .set _SMP_prvpt,_SMP_prvstart + PAGE_SIZE 97 .set _lapic,_SMP_prvstart + (2 * PAGE_SIZE) 98 .set _idlestack,_SMP_prvstart + (3 * PAGE_SIZE) 99 .set _idlestack_top,_SMP_prvstart + (5 * PAGE_SIZE) 100 .set _prv_CPAGE1,_SMP_prvstart + (5 * PAGE_SIZE) 101 .set _prv_CPAGE2,_SMP_prvstart + (6 * PAGE_SIZE) 102 .set _prv_CPAGE3,_SMP_prvstart + (7 * PAGE_SIZE) 103 .set _SMP_ioapic,_SMP_prvstart + (16 * PAGE_SIZE) 104 105 .globl _cpuid,_curproc,_curpcb,_npxproc,_runtime,_cpu_lockid 106 .globl _common_tss,_other_cpus,_my_idlePTD,_ss_tpr 107 .globl _prv_CMAP1,_prv_CMAP2,_prv_CMAP3 108 .globl _inside_intr 109 .set _cpuid,_SMP_prvpage+0 /* [0] */ 110 .set _curproc,_SMP_prvpage+4 /* [1] */ 111 .set _curpcb,_SMP_prvpage+8 /* [2] */ 112 .set _npxproc,_SMP_prvpage+12 /* [3] */ 113 .set _runtime,_SMP_prvpage+16 /* [4,5] */ 114 .set _cpu_lockid,_SMP_prvpage+24 /* [6] */ 115 .set _other_cpus,_SMP_prvpage+28 /* [7] bitmap of available CPUs, 116 excluding ourself */ 117 .set _my_idlePTD,_SMP_prvpage+32 /* [8] */ 118 .set _ss_tpr,_SMP_prvpage+36 /* [9] */ 119 .set _prv_CMAP1,_SMP_prvpage+40 /* [10] */ 120 .set _prv_CMAP2,_SMP_prvpage+44 /* [11] */ 121 .set _prv_CMAP3,_SMP_prvpage+48 /* [12] */ 122 .set _inside_intr,_SMP_prvpage+52 /* [13] */ 123 .set _common_tss,_SMP_prvpage+56 /* 102 (ie: 104) bytes long */ 124 125#ifdef VM86 126 .globl _common_tssd 127 .set _common_tssd,_common_tss+104 /* 8 bytes long */ 128 .globl _private_tss 129 .set _private_tss,_common_tss+112 130 .globl _my_tr 131 .set _my_tr,_common_tss+116 132#endif 133 134/* Fetch the .set's for the local apic */ 135#include "i386/i386/mp_apicdefs.s" 136 137#endif 138 139/* 140 * Globals 141 */ 142 .data 143 ALIGN_DATA /* just to be sure */ 144 145 .globl HIDENAME(tmpstk) 146 .space 0x2000 /* space for tmpstk - temporary stack */ 147HIDENAME(tmpstk): 148 149 .globl _boothowto,_bootdev 150 151 .globl _cpu,_cpu_vendor,_cpu_id,_bootinfo 152 .globl _cpu_high, _cpu_feature 153 154_cpu: .long 0 /* are we 386, 386sx, or 486 */ 155_cpu_id: .long 0 /* stepping ID */ 156_cpu_high: .long 0 /* highest arg to CPUID */ 157_cpu_feature: .long 0 /* features */ 158_cpu_vendor: .space 20 /* CPU origin code */ 159_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 160 161_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 162physfree: .long 0 /* phys addr of next free page */ 163 164#ifdef SMP 165cpu0pp: .long 0 /* phys addr cpu0 private pg */ 166cpu0pt: .long 0 /* phys addr cpu0 private pt */ 167 168 .globl _cpu0prvpage,_cpu0prvpt 169_cpu0prvpage: .long 0 /* relocated version */ 170_cpu0prvpt: .long 0 /* relocated version */ 171#endif /* SMP */ 172 173 .globl _IdlePTD 174_IdlePTD: .long 0 /* phys addr of kernel PTD */ 175 176#ifdef SMP 177 .globl _KPTphys 178#endif 179_KPTphys: .long 0 /* phys addr of kernel page tables */ 180 181 .globl _proc0paddr 182_proc0paddr: .long 0 /* address of proc 0 address space */ 183p0upa: .long 0 /* phys addr of proc0's UPAGES */ 184 185#ifdef BDE_DEBUGGER 186 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 187_bdb_exists: .long 0 188#endif 189 190 191/********************************************************************** 192 * 193 * Some handy macros 194 * 195 */ 196 197#define R(foo) ((foo)-KERNBASE) 198 199#define ALLOCPAGES(foo) \ 200 movl R(physfree), %esi ; \ 201 movl $((foo)*PAGE_SIZE), %eax ; \ 202 addl %esi, %eax ; \ 203 movl %eax, R(physfree) ; \ 204 movl %esi, %edi ; \ 205 movl $((foo)*PAGE_SIZE),%ecx ; \ 206 xorl %eax,%eax ; \ 207 cld ; \ 208 rep ; \ 209 stosb 210 211/* 212 * fillkpt 213 * eax = page frame address 214 * ebx = index into page table 215 * ecx = how many pages to map 216 * base = base address of page dir/table 217 * prot = protection bits 218 */ 219#define fillkpt(base, prot) \ 220 shll $2,%ebx ; \ 221 addl base,%ebx ; \ 222 orl $PG_V,%eax ; \ 223 orl prot,%eax ; \ 2241: movl %eax,(%ebx) ; \ 225 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 226 addl $4,%ebx ; /* next pte */ \ 227 loop 1b 228 229/* 230 * fillkptphys(prot) 231 * eax = physical address 232 * ecx = how many pages to map 233 * prot = protection bits 234 */ 235#define fillkptphys(prot) \ 236 movl %eax, %ebx ; \ 237 shrl $PAGE_SHIFT, %ebx ; \ 238 fillkpt(R(_KPTphys), prot) 239 240 .text 241/********************************************************************** 242 * 243 * This is where the bootblocks start us, set the ball rolling... 244 * 245 */ 246NON_GPROF_ENTRY(btext) 247 248#ifdef PC98 249 jmp 1f 250 .globl _pc98_system_parameter 251 .org 0x400 252_pc98_system_parameter: 253 .space 0x240 /* BIOS parameter block */ 2541: 255 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 256 movl $0xa1000,%esi 257 movl $0x100000,%edi 258 movl $0x0630,%ecx 259 cld 260 rep 261 movsb 262#else /* IBM-PC */ 263#ifdef BDE_DEBUGGER 264#ifdef BIOS_STEALS_3K 265 cmpl $0x0375c339,0x95504 266#else 267 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 268#endif 269 jne 1f 270 movb $1,R(_bdb_exists) 2711: 272#endif 273 274/* Tell the bios to warmboot next time */ 275 movw $0x1234,0x472 276#endif /* PC98 */ 277 278/* Set up a real frame in case the double return in newboot is executed. */ 279 pushl %ebp 280 movl %esp, %ebp 281 282/* Don't trust what the BIOS gives for eflags. */ 283 pushl $PSL_KERNEL 284 popfl 285 286/* 287 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 288 * to set %cs, %ds, %es and %ss. 289 */ 290 mov %ds, %ax 291 mov %ax, %fs 292 mov %ax, %gs 293 294 call recover_bootinfo 295 296/* Get onto a stack that we can trust. */ 297/* 298 * XXX this step is delayed in case recover_bootinfo needs to return via 299 * the old stack, but it need not be, since recover_bootinfo actually 300 * returns via the old frame. 301 */ 302 movl $R(HIDENAME(tmpstk)),%esp 303 304#ifdef PC98 305 testb $0x02,0x100620 /* pc98_machine_type & M_EPSON_PC98 */ 306 jz 3f 307 cmpb $0x0b,0x100624 /* epson_machine_id <= 0x0b */ 308 ja 3f 309 310 /* count up memory */ 311 movl $0x100000,%eax /* next, talley remaining memory */ 312 movl $0xFFF-0x100,%ecx 3131: movl 0(%eax),%ebx /* save location to check */ 314 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 315 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 316 jne 2f 317 movl %ebx,0(%eax) /* restore memory */ 318 addl $PAGE_SIZE,%eax 319 loop 1b 3202: subl $0x100000,%eax 321 shrl $17,%eax 322 movb %al,0x100401 3233: 324#endif 325 326 call identify_cpu 327 328/* clear bss */ 329/* 330 * XXX this should be done a little earlier. 331 * 332 * XXX we don't check that there is memory for our bss and page tables 333 * before using it. 334 * 335 * XXX the boot program somewhat bogusly clears the bss. We still have 336 * to do it in case we were unzipped by kzipboot. Then the boot program 337 * only clears kzipboot's bss. 338 * 339 * XXX the gdt and idt are still somewhere in the boot program. We 340 * depend on the convention that the boot program is below 1MB and we 341 * are above 1MB to keep the gdt and idt away from the bss and page 342 * tables. The idt is only used if BDE_DEBUGGER is enabled. 343 */ 344 movl $R(_end),%ecx 345 movl $R(_edata),%edi 346 subl %edi,%ecx 347 xorl %eax,%eax 348 cld 349 rep 350 stosb 351 352#if NAPM > 0 353/* 354 * XXX it's not clear that APM can live in the current environonment. 355 * Only pc-relative addressing works. 356 */ 357 call _apm_setup 358#endif 359 360 call create_pagetables 361 362#ifdef VM86 363/* 364 * If the CPU has support for VME, turn it on. 365 */ 366 testl $CPUID_VME, R(_cpu_feature) 367 jz 1f 368 movl %cr4, %eax 369 orl $CR4_VME, %eax 370 movl %eax, %cr4 3711: 372#endif /* VM86 */ 373 374#ifdef BDE_DEBUGGER 375/* 376 * Adjust as much as possible for paging before enabling paging so that the 377 * adjustments can be traced. 378 */ 379 call bdb_prepare_paging 380#endif 381 382/* Now enable paging */ 383 movl R(_IdlePTD), %eax 384 movl %eax,%cr3 /* load ptd addr into mmu */ 385 movl %cr0,%eax /* get control word */ 386 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 387 movl %eax,%cr0 /* and let's page NOW! */ 388 389#ifdef BDE_DEBUGGER 390/* 391 * Complete the adjustments for paging so that we can keep tracing through 392 * initi386() after the low (physical) addresses for the gdt and idt become 393 * invalid. 394 */ 395 call bdb_commit_paging 396#endif 397 398 pushl $begin /* jump to high virtualized address */ 399 ret 400 401/* now running relocated at KERNBASE where the system is linked to run */ 402begin: 403 /* set up bootstrap stack */ 404 movl _proc0paddr,%esp /* location of in-kernel pages */ 405 addl $UPAGES*PAGE_SIZE,%esp /* bootstrap stack end location */ 406 xorl %eax,%eax /* mark end of frames */ 407 movl %eax,%ebp 408 movl _proc0paddr,%eax 409 movl _IdlePTD, %esi 410 movl %esi,PCB_CR3(%eax) 411 412 movl physfree, %esi 413 pushl %esi /* value of first for init386(first) */ 414 call _init386 /* wire 386 chip for unix operation */ 415 popl %esi 416 417 .globl __ucodesel,__udatasel 418 419 pushl $0 /* unused */ 420 pushl __udatasel /* ss */ 421 pushl $0 /* esp - filled in by execve() */ 422 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 423 pushl __ucodesel /* cs */ 424 pushl $0 /* eip - filled in by execve() */ 425 subl $(12*4),%esp /* space for rest of registers */ 426 427 pushl %esp /* call main with frame pointer */ 428 call _main /* autoconfiguration, mountroot etc */ 429 430 hlt /* never returns to here */ 431 432/* 433 * When starting init, call this to configure the process for user 434 * mode. This will be inherited by other processes. 435 */ 436NON_GPROF_ENTRY(prepare_usermode) 437 /* 438 * Now we've run main() and determined what cpu-type we are, we can 439 * enable write protection and alignment checking on i486 cpus and 440 * above. 441 */ 442#if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU) 443 cmpl $CPUCLASS_386,_cpu_class 444 je 1f 445 movl %cr0,%eax /* get control word */ 446 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 447 movl %eax,%cr0 /* and do it */ 4481: 449#endif 450 /* 451 * on return from main(), we are process 1 452 * set up address space and stack so that we can 'return' to user mode 453 */ 454 movl __ucodesel,%eax 455 movl __udatasel,%ecx 456 457#if 0 458 movl %cx,%ds 459#endif 460 movl %cx,%es 461 movl %ax,%fs /* double map cs to fs */ 462 movl %cx,%gs /* and ds to gs */ 463 ret /* goto user! */ 464 465 466#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 467 468/* 469 * Signal trampoline, copied to top of user stack 470 */ 471NON_GPROF_ENTRY(sigcode) 472 call SIGF_HANDLER(%esp) 473 lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 474 /* copy at 8(%esp)) */ 475 pushl %eax 476 pushl %eax /* junk to fake return address */ 477 movl $SYS_sigreturn,%eax /* sigreturn() */ 478 LCALL(0x7,0) /* enter kernel with args on stack */ 479 hlt /* never gets here */ 480 ALIGN_TEXT 481_esigcode: 482 483 .data 484 .globl _szsigcode 485_szsigcode: 486 .long _esigcode-_sigcode 487 .text 488 489/********************************************************************** 490 * 491 * Recover the bootinfo passed to us from the boot program 492 * 493 */ 494recover_bootinfo: 495 /* 496 * This code is called in different ways depending on what loaded 497 * and started the kernel. This is used to detect how we get the 498 * arguments from the other code and what we do with them. 499 * 500 * Old disk boot blocks: 501 * (*btext)(howto, bootdev, cyloffset, esym); 502 * [return address == 0, and can NOT be returned to] 503 * [cyloffset was not supported by the FreeBSD boot code 504 * and always passed in as 0] 505 * [esym is also known as total in the boot code, and 506 * was never properly supported by the FreeBSD boot code] 507 * 508 * Old diskless netboot code: 509 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 510 * [return address != 0, and can NOT be returned to] 511 * If we are being booted by this code it will NOT work, 512 * so we are just going to halt if we find this case. 513 * 514 * New uniform boot code: 515 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 516 * [return address != 0, and can be returned to] 517 * 518 * There may seem to be a lot of wasted arguments in here, but 519 * that is so the newer boot code can still load very old kernels 520 * and old boot code can load new kernels. 521 */ 522 523 /* 524 * The old style disk boot blocks fake a frame on the stack and 525 * did an lret to get here. The frame on the stack has a return 526 * address of 0. 527 */ 528 cmpl $0,4(%ebp) 529 je olddiskboot 530 531 /* 532 * We have some form of return address, so this is either the 533 * old diskless netboot code, or the new uniform code. That can 534 * be detected by looking at the 5th argument, if it is 0 535 * we are being booted by the new uniform boot code. 536 */ 537 cmpl $0,24(%ebp) 538 je newboot 539 540 /* 541 * Seems we have been loaded by the old diskless boot code, we 542 * don't stand a chance of running as the diskless structure 543 * changed considerably between the two, so just halt. 544 */ 545 hlt 546 547 /* 548 * We have been loaded by the new uniform boot code. 549 * Let's check the bootinfo version, and if we do not understand 550 * it we return to the loader with a status of 1 to indicate this error 551 */ 552newboot: 553 movl 28(%ebp),%ebx /* &bootinfo.version */ 554 movl BI_VERSION(%ebx),%eax 555 cmpl $1,%eax /* We only understand version 1 */ 556 je 1f 557 movl $1,%eax /* Return status */ 558 leave 559 /* 560 * XXX this returns to our caller's caller (as is required) since 561 * we didn't set up a frame and our caller did. 562 */ 563 ret 564 5651: 566 /* 567 * If we have a kernelname copy it in 568 */ 569 movl BI_KERNELNAME(%ebx),%esi 570 cmpl $0,%esi 571 je 2f /* No kernelname */ 572 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 573 movl $R(_kernelname),%edi 574 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 575 je 1f 576 movb $'/',(%edi) 577 incl %edi 578 decl %ecx 5791: 580 cld 581 rep 582 movsb 583 5842: 585 /* 586 * Determine the size of the boot loader's copy of the bootinfo 587 * struct. This is impossible to do properly because old versions 588 * of the struct don't contain a size field and there are 2 old 589 * versions with the same version number. 590 */ 591 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 592 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 593 je got_bi_size /* no, sizeless version */ 594 movl BI_SIZE(%ebx),%ecx 595got_bi_size: 596 597 /* 598 * Copy the common part of the bootinfo struct 599 */ 600 movl %ebx,%esi 601 movl $R(_bootinfo),%edi 602 cmpl $BOOTINFO_SIZE,%ecx 603 jbe got_common_bi_size 604 movl $BOOTINFO_SIZE,%ecx 605got_common_bi_size: 606 cld 607 rep 608 movsb 609 610#ifdef NFS 611#ifndef BOOTP_NFSV3 612 /* 613 * If we have a nfs_diskless structure copy it in 614 */ 615 movl BI_NFS_DISKLESS(%ebx),%esi 616 cmpl $0,%esi 617 je olddiskboot 618 movl $R(_nfs_diskless),%edi 619 movl $NFSDISKLESS_SIZE,%ecx 620 cld 621 rep 622 movsb 623 movl $R(_nfs_diskless_valid),%edi 624 movl $1,(%edi) 625#endif 626#endif 627 628 /* 629 * The old style disk boot. 630 * (*btext)(howto, bootdev, cyloffset, esym); 631 * Note that the newer boot code just falls into here to pick 632 * up howto and bootdev, cyloffset and esym are no longer used 633 */ 634olddiskboot: 635 movl 8(%ebp),%eax 636 movl %eax,R(_boothowto) 637 movl 12(%ebp),%eax 638 movl %eax,R(_bootdev) 639 640#if defined(USERCONFIG_BOOT) && defined(USERCONFIG) 641#ifdef PC98 642 movl $0x90200, %esi 643#else 644 movl $0x10200, %esi 645#endif 646 movl $R(_userconfig_from_boot),%edi 647 movl $512,%ecx 648 cld 649 rep 650 movsb 651#endif /* USERCONFIG_BOOT */ 652 653 ret 654 655 656/********************************************************************** 657 * 658 * Identify the CPU and initialize anything special about it 659 * 660 */ 661identify_cpu: 662 663 /* Try to toggle alignment check flag; does not exist on 386. */ 664 pushfl 665 popl %eax 666 movl %eax,%ecx 667 orl $PSL_AC,%eax 668 pushl %eax 669 popfl 670 pushfl 671 popl %eax 672 xorl %ecx,%eax 673 andl $PSL_AC,%eax 674 pushl %ecx 675 popfl 676 677 testl %eax,%eax 678 jnz try486 679 680 /* NexGen CPU does not have aligment check flag. */ 681 pushfl 682 movl $0x5555, %eax 683 xorl %edx, %edx 684 movl $2, %ecx 685 clc 686 divl %ecx 687 jz trynexgen 688 popfl 689 movl $CPU_386,R(_cpu) 690 jmp 3f 691 692trynexgen: 693 popfl 694 movl $CPU_NX586,R(_cpu) 695 movl $0x4778654e,R(_cpu_vendor) # store vendor string 696 movl $0x72446e65,R(_cpu_vendor+4) 697 movl $0x6e657669,R(_cpu_vendor+8) 698 movl $0,R(_cpu_vendor+12) 699 jmp 3f 700 701try486: /* Try to toggle identification flag; does not exist on early 486s. */ 702 pushfl 703 popl %eax 704 movl %eax,%ecx 705 xorl $PSL_ID,%eax 706 pushl %eax 707 popfl 708 pushfl 709 popl %eax 710 xorl %ecx,%eax 711 andl $PSL_ID,%eax 712 pushl %ecx 713 popfl 714 715 testl %eax,%eax 716 jnz trycpuid 717 movl $CPU_486,R(_cpu) 718 719 /* 720 * Check Cyrix CPU 721 * Cyrix CPUs do not change the undefined flags following 722 * execution of the divide instruction which divides 5 by 2. 723 * 724 * Note: CPUID is enabled on M2, so it passes another way. 725 */ 726 pushfl 727 movl $0x5555, %eax 728 xorl %edx, %edx 729 movl $2, %ecx 730 clc 731 divl %ecx 732 jnc trycyrix 733 popfl 734 jmp 3f /* You may use Intel CPU. */ 735 736trycyrix: 737 popfl 738 /* 739 * IBM Bluelighting CPU also doesn't change the undefined flags. 740 * Because IBM doesn't disclose the information for Bluelighting 741 * CPU, we couldn't distinguish it from Cyrix's (including IBM 742 * brand of Cyrix CPUs). 743 */ 744 movl $0x69727943,R(_cpu_vendor) # store vendor string 745 movl $0x736e4978,R(_cpu_vendor+4) 746 movl $0x64616574,R(_cpu_vendor+8) 747 jmp 3f 748 749trycpuid: /* Use the `cpuid' instruction. */ 750 xorl %eax,%eax 751 .byte 0x0f,0xa2 # cpuid 0 752 movl %eax,R(_cpu_high) # highest capability 753 movl %ebx,R(_cpu_vendor) # store vendor string 754 movl %edx,R(_cpu_vendor+4) 755 movl %ecx,R(_cpu_vendor+8) 756 movb $0,R(_cpu_vendor+12) 757 758 movl $1,%eax 759 .byte 0x0f,0xa2 # cpuid 1 760 movl %eax,R(_cpu_id) # store cpu_id 761 movl %edx,R(_cpu_feature) # store cpu_feature 762 rorl $8,%eax # extract family type 763 andl $15,%eax 764 cmpl $5,%eax 765 jae 1f 766 767 /* less than Pentium; must be 486 */ 768 movl $CPU_486,R(_cpu) 769 jmp 3f 7701: 771 /* a Pentium? */ 772 cmpl $5,%eax 773 jne 2f 774 movl $CPU_586,R(_cpu) 775 jmp 3f 7762: 777 /* Greater than Pentium...call it a Pentium Pro */ 778 movl $CPU_686,R(_cpu) 7793: 780 ret 781 782 783/********************************************************************** 784 * 785 * Create the first page directory and its page tables. 786 * 787 */ 788 789create_pagetables: 790 791 testl $CPUID_PGE, R(_cpu_feature) 792 jz 1f 793 movl %cr4, %eax 794 orl $CR4_PGE, %eax 795 movl %eax, %cr4 7961: 797 798/* Find end of kernel image (rounded up to a page boundary). */ 799 movl $R(_end),%esi 800 801/* include symbols in "kernel image" if they are loaded and useful */ 802#ifdef DDB 803 movl R(_bootinfo+BI_ESYMTAB),%edi 804 testl %edi,%edi 805 je over_symalloc 806 movl %edi,%esi 807 movl $KERNBASE,%edi 808 addl %edi,R(_bootinfo+BI_SYMTAB) 809 addl %edi,R(_bootinfo+BI_ESYMTAB) 810over_symalloc: 811#endif 812 813 addl $PAGE_MASK,%esi 814 andl $~PAGE_MASK,%esi 815 movl %esi,R(_KERNend) /* save end of kernel */ 816 movl %esi,R(physfree) /* next free page is at end of kernel */ 817 818/* Allocate Kernel Page Tables */ 819 ALLOCPAGES(NKPT) 820 movl %esi,R(_KPTphys) 821 822/* Allocate Page Table Directory */ 823 ALLOCPAGES(1) 824 movl %esi,R(_IdlePTD) 825 826/* Allocate UPAGES */ 827 ALLOCPAGES(UPAGES) 828 movl %esi,R(p0upa) 829 addl $KERNBASE, %esi 830 movl %esi, R(_proc0paddr) 831 832#ifdef SMP 833/* Allocate cpu0's private data page */ 834 ALLOCPAGES(1) 835 movl %esi,R(cpu0pp) 836 addl $KERNBASE, %esi 837 movl %esi, R(_cpu0prvpage) /* relocated to KVM space */ 838 839/* Allocate cpu0's private page table for mapping priv page, apic, etc */ 840 ALLOCPAGES(1) 841 movl %esi,R(cpu0pt) 842 addl $KERNBASE, %esi 843 movl %esi, R(_cpu0prvpt) /* relocated to KVM space */ 844#endif /* SMP */ 845 846/* Map read-only from zero to the end of the kernel text section */ 847 xorl %eax, %eax 848#ifdef BDE_DEBUGGER 849/* If the debugger is present, actually map everything read-write. */ 850 cmpl $0,R(_bdb_exists) 851 jne map_read_write 852#endif 853 xorl %edx,%edx 854 855#if !defined(SMP) 856 testl $CPUID_PGE, R(_cpu_feature) 857 jz 2f 858 orl $PG_G,%edx 859#endif 860 8612: movl $R(_etext),%ecx 862 addl $PAGE_MASK,%ecx 863 shrl $PAGE_SHIFT,%ecx 864 fillkptphys(%edx) 865 866/* Map read-write, data, bss and symbols */ 867 movl $R(_etext),%eax 868 addl $PAGE_MASK, %eax 869 andl $~PAGE_MASK, %eax 870map_read_write: 871 movl $PG_RW,%edx 872#if !defined(SMP) 873 testl $CPUID_PGE, R(_cpu_feature) 874 jz 1f 875 orl $PG_G,%edx 876#endif 877 8781: movl R(_KERNend),%ecx 879 subl %eax,%ecx 880 shrl $PAGE_SHIFT,%ecx 881 fillkptphys(%edx) 882 883/* Map page directory. */ 884 movl R(_IdlePTD), %eax 885 movl $1, %ecx 886 fillkptphys($PG_RW) 887 888/* Map proc0's UPAGES in the physical way ... */ 889 movl R(p0upa), %eax 890 movl $UPAGES, %ecx 891 fillkptphys($PG_RW) 892 893/* Map ISA hole */ 894 movl $ISA_HOLE_START, %eax 895 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 896 fillkptphys($PG_RW) 897 898#ifdef SMP 899/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 900 movl R(cpu0pp), %eax 901 movl $1, %ecx 902 fillkptphys($PG_RW) 903 904/* Map cpu0's private page table into global kmem FWIW */ 905 movl R(cpu0pt), %eax 906 movl $1, %ecx 907 fillkptphys($PG_RW) 908 909/* Map the private page into the private page table into private space */ 910 movl R(cpu0pp), %eax 911 movl $0, %ebx /* pte offset = 0 */ 912 movl $1, %ecx /* one private page coming right up */ 913 fillkpt(R(cpu0pt), $PG_RW) 914 915/* Map the page table page into private space */ 916 movl R(cpu0pt), %eax 917 movl $1, %ebx /* pte offset = 1 */ 918 movl $1, %ecx /* one private pt coming right up */ 919 fillkpt(R(cpu0pt), $PG_RW) 920 921/* ... and put the page table table in the pde. */ 922 movl R(cpu0pt), %eax 923 movl $MPPTDI, %ebx 924 movl $1, %ecx 925 fillkpt(R(_IdlePTD), $PG_RW) 926#endif /* SMP */ 927 928/* install a pde for temporary double map of bottom of VA */ 929 movl R(_KPTphys), %eax 930 xorl %ebx, %ebx 931 movl $1, %ecx 932 fillkpt(R(_IdlePTD), $PG_RW) 933 934/* install pde's for pt's */ 935 movl R(_KPTphys), %eax 936 movl $KPTDI, %ebx 937 movl $NKPT, %ecx 938 fillkpt(R(_IdlePTD), $PG_RW) 939 940/* install a pde recursively mapping page directory as a page table */ 941 movl R(_IdlePTD), %eax 942 movl $PTDPTDI, %ebx 943 movl $1,%ecx 944 fillkpt(R(_IdlePTD), $PG_RW) 945 946 ret 947 948#ifdef BDE_DEBUGGER 949bdb_prepare_paging: 950 cmpl $0,R(_bdb_exists) 951 je bdb_prepare_paging_exit 952 953 subl $6,%esp 954 955 /* 956 * Copy and convert debugger entries from the bootstrap gdt and idt 957 * to the kernel gdt and idt. Everything is still in low memory. 958 * Tracing continues to work after paging is enabled because the 959 * low memory addresses remain valid until everything is relocated. 960 * However, tracing through the setidt() that initializes the trace 961 * trap will crash. 962 */ 963 sgdt (%esp) 964 movl 2(%esp),%esi /* base address of bootstrap gdt */ 965 movl $R(_gdt),%edi 966 movl %edi,2(%esp) /* prepare to load kernel gdt */ 967 movl $8*18/4,%ecx 968 cld 969 rep /* copy gdt */ 970 movsl 971 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 972 movb $0x92,-8+5(%edi) 973 lgdt (%esp) 974 975 sidt (%esp) 976 movl 2(%esp),%esi /* base address of current idt */ 977 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 978 movw 8(%esi),%ax 979 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 980 movl 8+2(%esi),%eax 981 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 982 movl 24+4(%esi),%eax /* same for bpt descriptor */ 983 movw 24(%esi),%ax 984 movl %eax,R(bdb_bpt_ljmp+1) 985 movl 24+2(%esi),%eax 986 movw %ax,R(bdb_bpt_ljmp+5) 987 movl $R(_idt),%edi 988 movl %edi,2(%esp) /* prepare to load kernel idt */ 989 movl $8*4/4,%ecx 990 cld 991 rep /* copy idt */ 992 movsl 993 lidt (%esp) 994 995 addl $6,%esp 996 997bdb_prepare_paging_exit: 998 ret 999 1000/* Relocate debugger gdt entries and gdt and idt pointers. */ 1001bdb_commit_paging: 1002 cmpl $0,_bdb_exists 1003 je bdb_commit_paging_exit 1004 1005 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 1006 movl $9,%ecx 1007reloc_gdt: 1008 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 1009 addl $8,%eax /* now KERNBASE>>24 */ 1010 loop reloc_gdt 1011 1012 subl $6,%esp 1013 sgdt (%esp) 1014 addl $KERNBASE,2(%esp) 1015 lgdt (%esp) 1016 sidt (%esp) 1017 addl $KERNBASE,2(%esp) 1018 lidt (%esp) 1019 addl $6,%esp 1020 1021 int $3 1022 1023bdb_commit_paging_exit: 1024 ret 1025 1026#endif /* BDE_DEBUGGER */ 1027