locore.s revision 28641
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 1.3 1997/08/23 04:10:36 smp Exp smp $ 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 .set _SMP_prvpage,_SMP_prvstart 94 .set _SMP_prvpt,_SMP_prvstart + PAGE_SIZE 95 .set _lapic,_SMP_prvstart + (2 * PAGE_SIZE) 96 .set _SMP_ioapic,_SMP_prvstart + (16 * PAGE_SIZE) 97 98 .globl _cpuid,_curproc,_curpcb,_npxproc,_runtime,_cpu_lockid 99 .globl _common_tss,_other_cpus,_ss_tpr 100 .set _cpuid,_SMP_prvpage+0 101 .set _curproc,_SMP_prvpage+4 102 .set _curpcb,_SMP_prvpage+8 103 .set _npxproc,_SMP_prvpage+12 104 .set _runtime,_SMP_prvpage+16 /* 8 bytes struct timeval */ 105 .set _cpu_lockid,_SMP_prvpage+24 106 .set _common_tss,_SMP_prvpage+28 /* 104 bytes long, next = 132 */ 107 .set _other_cpus,_SMP_prvpage+132 /* bitmap of available CPUs, 108 excluding ourself */ 109 .set _ss_tpr,_SMP_prvpage+136 110 111/* Fetch the .set's for the local apic */ 112#include "i386/i386/mp_apicdefs.s" 113 114#endif 115 116/* 117 * Globals 118 */ 119 .data 120 ALIGN_DATA /* just to be sure */ 121 122 .globl HIDENAME(tmpstk) 123 .space 0x2000 /* space for tmpstk - temporary stack */ 124HIDENAME(tmpstk): 125 126 .globl _boothowto,_bootdev 127 128 .globl _cpu,_cpu_vendor,_cpu_id,_bootinfo 129 .globl _cpu_high, _cpu_feature 130 131_cpu: .long 0 /* are we 386, 386sx, or 486 */ 132_cpu_id: .long 0 /* stepping ID */ 133_cpu_high: .long 0 /* highest arg to CPUID */ 134_cpu_feature: .long 0 /* features */ 135_cpu_vendor: .space 20 /* CPU origin code */ 136_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 137 138_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 139physfree: .long 0 /* phys addr of next free page */ 140 141#ifdef SMP 142cpu0pp: .long 0 /* phys addr cpu0 private pg */ 143cpu0pt: .long 0 /* phys addr cpu0 private pt */ 144 145 .globl _cpu0prvpage,_cpu0prvpt 146_cpu0prvpage: .long 0 /* relocated version */ 147_cpu0prvpt: .long 0 /* relocated version */ 148#endif /* SMP */ 149 150 .globl _IdlePTD 151_IdlePTD: .long 0 /* phys addr of kernel PTD */ 152 153#ifdef SMP 154 .globl _KPTphys 155#endif 156_KPTphys: .long 0 /* phys addr of kernel page tables */ 157 158 .globl _proc0paddr 159_proc0paddr: .long 0 /* address of proc 0 address space */ 160p0upa: .long 0 /* phys addr of proc0's UPAGES */ 161 162#ifdef BDE_DEBUGGER 163 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 164_bdb_exists: .long 0 165#endif 166 167 168/********************************************************************** 169 * 170 * Some handy macros 171 * 172 */ 173 174#define R(foo) ((foo)-KERNBASE) 175 176#define ALLOCPAGES(foo) \ 177 movl R(physfree), %esi ; \ 178 movl $((foo)*PAGE_SIZE), %eax ; \ 179 addl %esi, %eax ; \ 180 movl %eax, R(physfree) ; \ 181 movl %esi, %edi ; \ 182 movl $((foo)*PAGE_SIZE),%ecx ; \ 183 xorl %eax,%eax ; \ 184 cld ; \ 185 rep ; \ 186 stosb 187 188/* 189 * fillkpt 190 * eax = page frame address 191 * ebx = index into page table 192 * ecx = how many pages to map 193 * base = base address of page dir/table 194 * prot = protection bits 195 */ 196#define fillkpt(base, prot) \ 197 shll $2,%ebx ; \ 198 addl base,%ebx ; \ 199 orl $PG_V,%eax ; \ 200 orl prot,%eax ; \ 2011: movl %eax,(%ebx) ; \ 202 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 203 addl $4,%ebx ; /* next pte */ \ 204 loop 1b 205 206/* 207 * fillkptphys(prot) 208 * eax = physical address 209 * ecx = how many pages to map 210 * prot = protection bits 211 */ 212#define fillkptphys(prot) \ 213 movl %eax, %ebx ; \ 214 shrl $PAGE_SHIFT, %ebx ; \ 215 fillkpt(R(_KPTphys), prot) 216 217 .text 218/********************************************************************** 219 * 220 * This is where the bootblocks start us, set the ball rolling... 221 * 222 */ 223NON_GPROF_ENTRY(btext) 224 225#ifdef PC98 226 jmp 1f 227 .globl _pc98_system_parameter 228 .org 0x400 229_pc98_system_parameter: 230 .space 0x240 /* BIOS parameter block */ 2311: 232 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 233 movl $0xa1000,%esi 234 movl $0x100000,%edi 235 movl $0x0630,%ecx 236 cld 237 rep 238 movsb 239#else /* IBM-PC */ 240#ifdef BDE_DEBUGGER 241#ifdef BIOS_STEALS_3K 242 cmpl $0x0375c339,0x95504 243#else 244 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 245#endif 246 jne 1f 247 movb $1,R(_bdb_exists) 2481: 249#endif 250 251/* Tell the bios to warmboot next time */ 252 movw $0x1234,0x472 253#endif /* PC98 */ 254 255/* Set up a real frame in case the double return in newboot is executed. */ 256 pushl %ebp 257 movl %esp, %ebp 258 259/* Don't trust what the BIOS gives for eflags. */ 260 pushl $PSL_KERNEL 261 popfl 262 263/* 264 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 265 * to set %cs, %ds, %es and %ss. 266 */ 267 mov %ds, %ax 268 mov %ax, %fs 269 mov %ax, %gs 270 271 call recover_bootinfo 272 273/* Get onto a stack that we can trust. */ 274/* 275 * XXX this step is delayed in case recover_bootinfo needs to return via 276 * the old stack, but it need not be, since recover_bootinfo actually 277 * returns via the old frame. 278 */ 279 movl $R(HIDENAME(tmpstk)),%esp 280 281#ifdef PC98 282 testb $0x02,0x100620 /* pc98_machine_type & M_EPSON_PC98 */ 283 jz 3f 284 cmpb $0x0b,0x100624 /* epson_machine_id <= 0x0b */ 285 ja 3f 286 287 /* count up memory */ 288 movl $0x100000,%eax /* next, talley remaining memory */ 289 movl $0xFFF-0x100,%ecx 2901: movl 0(%eax),%ebx /* save location to check */ 291 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 292 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 293 jne 2f 294 movl %ebx,0(%eax) /* restore memory */ 295 addl $PAGE_SIZE,%eax 296 loop 1b 2972: subl $0x100000,%eax 298 shrl $17,%eax 299 movb %al,0x100401 3003: 301#endif 302 303 call identify_cpu 304 305/* clear bss */ 306/* 307 * XXX this should be done a little earlier. 308 * 309 * XXX we don't check that there is memory for our bss and page tables 310 * before using it. 311 * 312 * XXX the boot program somewhat bogusly clears the bss. We still have 313 * to do it in case we were unzipped by kzipboot. Then the boot program 314 * only clears kzipboot's bss. 315 * 316 * XXX the gdt and idt are still somewhere in the boot program. We 317 * depend on the convention that the boot program is below 1MB and we 318 * are above 1MB to keep the gdt and idt away from the bss and page 319 * tables. The idt is only used if BDE_DEBUGGER is enabled. 320 */ 321 movl $R(_end),%ecx 322 movl $R(_edata),%edi 323 subl %edi,%ecx 324 xorl %eax,%eax 325 cld 326 rep 327 stosb 328 329#if NAPM > 0 330/* 331 * XXX it's not clear that APM can live in the current environonment. 332 * Only pc-relative addressing works. 333 */ 334 call _apm_setup 335#endif 336 337 call create_pagetables 338 339#ifdef VM86 340/* 341 * If the CPU has support for VME, turn it on. 342 */ 343 testl $CPUID_VME, R(_cpu_feature) 344 jz 1f 345 movl %cr4, %eax 346 orl $CR4_VME, %eax 347 movl %eax, %cr4 3481: 349#endif /* VM86 */ 350 351#ifdef BDE_DEBUGGER 352/* 353 * Adjust as much as possible for paging before enabling paging so that the 354 * adjustments can be traced. 355 */ 356 call bdb_prepare_paging 357#endif 358 359/* Now enable paging */ 360 movl R(_IdlePTD), %eax 361 movl %eax,%cr3 /* load ptd addr into mmu */ 362 movl %cr0,%eax /* get control word */ 363 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 364 movl %eax,%cr0 /* and let's page NOW! */ 365 366#ifdef BDE_DEBUGGER 367/* 368 * Complete the adjustments for paging so that we can keep tracing through 369 * initi386() after the low (physical) addresses for the gdt and idt become 370 * invalid. 371 */ 372 call bdb_commit_paging 373#endif 374 375 pushl $begin /* jump to high virtualized address */ 376 ret 377 378/* now running relocated at KERNBASE where the system is linked to run */ 379begin: 380 /* set up bootstrap stack */ 381 movl _proc0paddr,%esp /* location of in-kernel pages */ 382 addl $UPAGES*PAGE_SIZE,%esp /* bootstrap stack end location */ 383 xorl %eax,%eax /* mark end of frames */ 384 movl %eax,%ebp 385 movl _proc0paddr,%eax 386 movl _IdlePTD, %esi 387 movl %esi,PCB_CR3(%eax) 388 389 movl physfree, %esi 390 pushl %esi /* value of first for init386(first) */ 391 call _init386 /* wire 386 chip for unix operation */ 392 popl %esi 393 394 .globl __ucodesel,__udatasel 395 396 pushl $0 /* unused */ 397 pushl __udatasel /* ss */ 398 pushl $0 /* esp - filled in by execve() */ 399 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 400 pushl __ucodesel /* cs */ 401 pushl $0 /* eip - filled in by execve() */ 402 subl $(12*4),%esp /* space for rest of registers */ 403 404 pushl %esp /* call main with frame pointer */ 405 call _main /* autoconfiguration, mountroot etc */ 406 407 hlt /* never returns to here */ 408 409/* 410 * When starting init, call this to configure the process for user 411 * mode. This will be inherited by other processes. 412 */ 413NON_GPROF_ENTRY(prepare_usermode) 414 /* 415 * Now we've run main() and determined what cpu-type we are, we can 416 * enable write protection and alignment checking on i486 cpus and 417 * above. 418 */ 419#if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU) 420 cmpl $CPUCLASS_386,_cpu_class 421 je 1f 422 movl %cr0,%eax /* get control word */ 423 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 424 movl %eax,%cr0 /* and do it */ 4251: 426#endif 427 /* 428 * on return from main(), we are process 1 429 * set up address space and stack so that we can 'return' to user mode 430 */ 431 movl __ucodesel,%eax 432 movl __udatasel,%ecx 433 434#if 0 435 movl %cx,%ds 436#endif 437 movl %cx,%es 438 movl %ax,%fs /* double map cs to fs */ 439 movl %cx,%gs /* and ds to gs */ 440 ret /* goto user! */ 441 442 443#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 444 445/* 446 * Signal trampoline, copied to top of user stack 447 */ 448NON_GPROF_ENTRY(sigcode) 449 call SIGF_HANDLER(%esp) 450 lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 451 /* copy at 8(%esp)) */ 452 pushl %eax 453 pushl %eax /* junk to fake return address */ 454 movl $SYS_sigreturn,%eax /* sigreturn() */ 455 LCALL(0x7,0) /* enter kernel with args on stack */ 456 hlt /* never gets here */ 457 ALIGN_TEXT 458_esigcode: 459 460 .data 461 .globl _szsigcode 462_szsigcode: 463 .long _esigcode-_sigcode 464 .text 465 466/********************************************************************** 467 * 468 * Recover the bootinfo passed to us from the boot program 469 * 470 */ 471recover_bootinfo: 472 /* 473 * This code is called in different ways depending on what loaded 474 * and started the kernel. This is used to detect how we get the 475 * arguments from the other code and what we do with them. 476 * 477 * Old disk boot blocks: 478 * (*btext)(howto, bootdev, cyloffset, esym); 479 * [return address == 0, and can NOT be returned to] 480 * [cyloffset was not supported by the FreeBSD boot code 481 * and always passed in as 0] 482 * [esym is also known as total in the boot code, and 483 * was never properly supported by the FreeBSD boot code] 484 * 485 * Old diskless netboot code: 486 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 487 * [return address != 0, and can NOT be returned to] 488 * If we are being booted by this code it will NOT work, 489 * so we are just going to halt if we find this case. 490 * 491 * New uniform boot code: 492 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 493 * [return address != 0, and can be returned to] 494 * 495 * There may seem to be a lot of wasted arguments in here, but 496 * that is so the newer boot code can still load very old kernels 497 * and old boot code can load new kernels. 498 */ 499 500 /* 501 * The old style disk boot blocks fake a frame on the stack and 502 * did an lret to get here. The frame on the stack has a return 503 * address of 0. 504 */ 505 cmpl $0,4(%ebp) 506 je olddiskboot 507 508 /* 509 * We have some form of return address, so this is either the 510 * old diskless netboot code, or the new uniform code. That can 511 * be detected by looking at the 5th argument, if it is 0 512 * we are being booted by the new uniform boot code. 513 */ 514 cmpl $0,24(%ebp) 515 je newboot 516 517 /* 518 * Seems we have been loaded by the old diskless boot code, we 519 * don't stand a chance of running as the diskless structure 520 * changed considerably between the two, so just halt. 521 */ 522 hlt 523 524 /* 525 * We have been loaded by the new uniform boot code. 526 * Let's check the bootinfo version, and if we do not understand 527 * it we return to the loader with a status of 1 to indicate this error 528 */ 529newboot: 530 movl 28(%ebp),%ebx /* &bootinfo.version */ 531 movl BI_VERSION(%ebx),%eax 532 cmpl $1,%eax /* We only understand version 1 */ 533 je 1f 534 movl $1,%eax /* Return status */ 535 leave 536 /* 537 * XXX this returns to our caller's caller (as is required) since 538 * we didn't set up a frame and our caller did. 539 */ 540 ret 541 5421: 543 /* 544 * If we have a kernelname copy it in 545 */ 546 movl BI_KERNELNAME(%ebx),%esi 547 cmpl $0,%esi 548 je 2f /* No kernelname */ 549 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 550 movl $R(_kernelname),%edi 551 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 552 je 1f 553 movb $'/',(%edi) 554 incl %edi 555 decl %ecx 5561: 557 cld 558 rep 559 movsb 560 5612: 562 /* 563 * Determine the size of the boot loader's copy of the bootinfo 564 * struct. This is impossible to do properly because old versions 565 * of the struct don't contain a size field and there are 2 old 566 * versions with the same version number. 567 */ 568 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 569 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 570 je got_bi_size /* no, sizeless version */ 571 movl BI_SIZE(%ebx),%ecx 572got_bi_size: 573 574 /* 575 * Copy the common part of the bootinfo struct 576 */ 577 movl %ebx,%esi 578 movl $R(_bootinfo),%edi 579 cmpl $BOOTINFO_SIZE,%ecx 580 jbe got_common_bi_size 581 movl $BOOTINFO_SIZE,%ecx 582got_common_bi_size: 583 cld 584 rep 585 movsb 586 587#ifdef NFS 588#ifndef BOOTP_NFSV3 589 /* 590 * If we have a nfs_diskless structure copy it in 591 */ 592 movl BI_NFS_DISKLESS(%ebx),%esi 593 cmpl $0,%esi 594 je olddiskboot 595 movl $R(_nfs_diskless),%edi 596 movl $NFSDISKLESS_SIZE,%ecx 597 cld 598 rep 599 movsb 600 movl $R(_nfs_diskless_valid),%edi 601 movl $1,(%edi) 602#endif 603#endif 604 605 /* 606 * The old style disk boot. 607 * (*btext)(howto, bootdev, cyloffset, esym); 608 * Note that the newer boot code just falls into here to pick 609 * up howto and bootdev, cyloffset and esym are no longer used 610 */ 611olddiskboot: 612 movl 8(%ebp),%eax 613 movl %eax,R(_boothowto) 614 movl 12(%ebp),%eax 615 movl %eax,R(_bootdev) 616 617#if defined(USERCONFIG_BOOT) && defined(USERCONFIG) 618#ifdef PC98 619 movl $0x90200, %esi 620#else 621 movl $0x10200, %esi 622#endif 623 movl $R(_userconfig_from_boot),%edi 624 movl $512,%ecx 625 cld 626 rep 627 movsb 628#endif /* USERCONFIG_BOOT */ 629 630 ret 631 632 633/********************************************************************** 634 * 635 * Identify the CPU and initialize anything special about it 636 * 637 */ 638identify_cpu: 639 640 /* Try to toggle alignment check flag; does not exist on 386. */ 641 pushfl 642 popl %eax 643 movl %eax,%ecx 644 orl $PSL_AC,%eax 645 pushl %eax 646 popfl 647 pushfl 648 popl %eax 649 xorl %ecx,%eax 650 andl $PSL_AC,%eax 651 pushl %ecx 652 popfl 653 654 testl %eax,%eax 655 jnz try486 656 657 /* NexGen CPU does not have aligment check flag. */ 658 pushfl 659 movl $0x5555, %eax 660 xorl %edx, %edx 661 movl $2, %ecx 662 clc 663 divl %ecx 664 jz trynexgen 665 popfl 666 movl $CPU_386,R(_cpu) 667 jmp 3f 668 669trynexgen: 670 popfl 671 movl $CPU_NX586,R(_cpu) 672 movl $0x4778654e,R(_cpu_vendor) # store vendor string 673 movl $0x72446e65,R(_cpu_vendor+4) 674 movl $0x6e657669,R(_cpu_vendor+8) 675 movl $0,R(_cpu_vendor+12) 676 jmp 3f 677 678try486: /* Try to toggle identification flag; does not exist on early 486s. */ 679 pushfl 680 popl %eax 681 movl %eax,%ecx 682 xorl $PSL_ID,%eax 683 pushl %eax 684 popfl 685 pushfl 686 popl %eax 687 xorl %ecx,%eax 688 andl $PSL_ID,%eax 689 pushl %ecx 690 popfl 691 692 testl %eax,%eax 693 jnz trycpuid 694 movl $CPU_486,R(_cpu) 695 696 /* 697 * Check Cyrix CPU 698 * Cyrix CPUs do not change the undefined flags following 699 * execution of the divide instruction which divides 5 by 2. 700 * 701 * Note: CPUID is enabled on M2, so it passes another way. 702 */ 703 pushfl 704 movl $0x5555, %eax 705 xorl %edx, %edx 706 movl $2, %ecx 707 clc 708 divl %ecx 709 jnc trycyrix 710 popfl 711 jmp 3f /* You may use Intel CPU. */ 712 713trycyrix: 714 popfl 715 /* 716 * IBM Bluelighting CPU also doesn't change the undefined flags. 717 * Because IBM doesn't disclose the information for Bluelighting 718 * CPU, we couldn't distinguish it from Cyrix's (including IBM 719 * brand of Cyrix CPUs). 720 */ 721 movl $0x69727943,R(_cpu_vendor) # store vendor string 722 movl $0x736e4978,R(_cpu_vendor+4) 723 movl $0x64616574,R(_cpu_vendor+8) 724 jmp 3f 725 726trycpuid: /* Use the `cpuid' instruction. */ 727 xorl %eax,%eax 728 .byte 0x0f,0xa2 # cpuid 0 729 movl %eax,R(_cpu_high) # highest capability 730 movl %ebx,R(_cpu_vendor) # store vendor string 731 movl %edx,R(_cpu_vendor+4) 732 movl %ecx,R(_cpu_vendor+8) 733 movb $0,R(_cpu_vendor+12) 734 735 movl $1,%eax 736 .byte 0x0f,0xa2 # cpuid 1 737 movl %eax,R(_cpu_id) # store cpu_id 738 movl %edx,R(_cpu_feature) # store cpu_feature 739 rorl $8,%eax # extract family type 740 andl $15,%eax 741 cmpl $5,%eax 742 jae 1f 743 744 /* less than Pentium; must be 486 */ 745 movl $CPU_486,R(_cpu) 746 jmp 3f 7471: 748 /* a Pentium? */ 749 cmpl $5,%eax 750 jne 2f 751 movl $CPU_586,R(_cpu) 752 jmp 3f 7532: 754 /* Greater than Pentium...call it a Pentium Pro */ 755 movl $CPU_686,R(_cpu) 7563: 757 ret 758 759 760/********************************************************************** 761 * 762 * Create the first page directory and its page tables. 763 * 764 */ 765 766create_pagetables: 767 768 testl $CPUID_PGE, R(_cpu_feature) 769 jz 1f 770 movl %cr4, %eax 771 orl $CR4_PGE, %eax 772 movl %eax, %cr4 7731: 774 775/* Find end of kernel image (rounded up to a page boundary). */ 776 movl $R(_end),%esi 777 778/* include symbols in "kernel image" if they are loaded and useful */ 779#ifdef DDB 780 movl R(_bootinfo+BI_ESYMTAB),%edi 781 testl %edi,%edi 782 je over_symalloc 783 movl %edi,%esi 784 movl $KERNBASE,%edi 785 addl %edi,R(_bootinfo+BI_SYMTAB) 786 addl %edi,R(_bootinfo+BI_ESYMTAB) 787over_symalloc: 788#endif 789 790 addl $PAGE_MASK,%esi 791 andl $~PAGE_MASK,%esi 792 movl %esi,R(_KERNend) /* save end of kernel */ 793 movl %esi,R(physfree) /* next free page is at end of kernel */ 794 795/* Allocate Kernel Page Tables */ 796 ALLOCPAGES(NKPT) 797 movl %esi,R(_KPTphys) 798 799/* Allocate Page Table Directory */ 800 ALLOCPAGES(1) 801 movl %esi,R(_IdlePTD) 802 803/* Allocate UPAGES */ 804 ALLOCPAGES(UPAGES) 805 movl %esi,R(p0upa) 806 addl $KERNBASE, %esi 807 movl %esi, R(_proc0paddr) 808 809#ifdef SMP 810/* Allocate cpu0's private data page */ 811 ALLOCPAGES(1) 812 movl %esi,R(cpu0pp) 813 addl $KERNBASE, %esi 814 movl %esi, R(_cpu0prvpage) /* relocated to KVM space */ 815 816/* Allocate cpu0's private page table for mapping priv page, apic, etc */ 817 ALLOCPAGES(1) 818 movl %esi,R(cpu0pt) 819 addl $KERNBASE, %esi 820 movl %esi, R(_cpu0prvpt) /* relocated to KVM space */ 821#endif /* SMP */ 822 823/* Map read-only from zero to the end of the kernel text section */ 824 xorl %eax, %eax 825#ifdef BDE_DEBUGGER 826/* If the debugger is present, actually map everything read-write. */ 827 cmpl $0,R(_bdb_exists) 828 jne map_read_write 829#endif 830 xorl %edx,%edx 831 832#if !defined(SMP) 833 testl $CPUID_PGE, R(_cpu_feature) 834 jz 2f 835 orl $PG_G,%edx 836#endif 837 8382: movl $R(_etext),%ecx 839 addl $PAGE_MASK,%ecx 840 shrl $PAGE_SHIFT,%ecx 841 fillkptphys(%edx) 842 843/* Map read-write, data, bss and symbols */ 844 movl $R(_etext),%eax 845 addl $PAGE_MASK, %eax 846 andl $~PAGE_MASK, %eax 847map_read_write: 848 movl $PG_RW,%edx 849#if !defined(SMP) 850 testl $CPUID_PGE, R(_cpu_feature) 851 jz 1f 852 orl $PG_G,%edx 853#endif 854 8551: movl R(_KERNend),%ecx 856 subl %eax,%ecx 857 shrl $PAGE_SHIFT,%ecx 858 fillkptphys(%edx) 859 860/* Map page directory. */ 861 movl R(_IdlePTD), %eax 862 movl $1, %ecx 863 fillkptphys($PG_RW) 864 865/* Map proc0's UPAGES in the physical way ... */ 866 movl R(p0upa), %eax 867 movl $UPAGES, %ecx 868 fillkptphys($PG_RW) 869 870/* Map ISA hole */ 871 movl $ISA_HOLE_START, %eax 872 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 873 fillkptphys($PG_RW) 874 875#ifdef SMP 876/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 877 movl R(cpu0pp), %eax 878 movl $1, %ecx 879 fillkptphys($PG_RW) 880 881/* Map cpu0's private page table into global kmem FWIW */ 882 movl R(cpu0pt), %eax 883 movl $1, %ecx 884 fillkptphys($PG_RW) 885 886/* Map the private page into the private page table into private space */ 887 movl R(cpu0pp), %eax 888 movl $0, %ebx /* pte offset = 0 */ 889 movl $1, %ecx /* one private page coming right up */ 890 fillkpt(R(cpu0pt), $PG_RW) 891 892/* Map the page table page into private space */ 893 movl R(cpu0pt), %eax 894 movl $1, %ebx /* pte offset = 1 */ 895 movl $1, %ecx /* one private pt coming right up */ 896 fillkpt(R(cpu0pt), $PG_RW) 897 898/* ... and put the page table table in the pde. */ 899 movl R(cpu0pt), %eax 900 movl $MPPTDI, %ebx 901 movl $1, %ecx 902 fillkpt(R(_IdlePTD), $PG_RW) 903#endif /* SMP */ 904 905/* install a pde for temporary double map of bottom of VA */ 906 movl R(_KPTphys), %eax 907 xorl %ebx, %ebx 908 movl $1, %ecx 909 fillkpt(R(_IdlePTD), $PG_RW) 910 911/* install pde's for pt's */ 912 movl R(_KPTphys), %eax 913 movl $KPTDI, %ebx 914 movl $NKPT, %ecx 915 fillkpt(R(_IdlePTD), $PG_RW) 916 917/* install a pde recursively mapping page directory as a page table */ 918 movl R(_IdlePTD), %eax 919 movl $PTDPTDI, %ebx 920 movl $1,%ecx 921 fillkpt(R(_IdlePTD), $PG_RW) 922 923 ret 924 925#ifdef BDE_DEBUGGER 926bdb_prepare_paging: 927 cmpl $0,R(_bdb_exists) 928 je bdb_prepare_paging_exit 929 930 subl $6,%esp 931 932 /* 933 * Copy and convert debugger entries from the bootstrap gdt and idt 934 * to the kernel gdt and idt. Everything is still in low memory. 935 * Tracing continues to work after paging is enabled because the 936 * low memory addresses remain valid until everything is relocated. 937 * However, tracing through the setidt() that initializes the trace 938 * trap will crash. 939 */ 940 sgdt (%esp) 941 movl 2(%esp),%esi /* base address of bootstrap gdt */ 942 movl $R(_gdt),%edi 943 movl %edi,2(%esp) /* prepare to load kernel gdt */ 944 movl $8*18/4,%ecx 945 cld 946 rep /* copy gdt */ 947 movsl 948 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 949 movb $0x92,-8+5(%edi) 950 lgdt (%esp) 951 952 sidt (%esp) 953 movl 2(%esp),%esi /* base address of current idt */ 954 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 955 movw 8(%esi),%ax 956 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 957 movl 8+2(%esi),%eax 958 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 959 movl 24+4(%esi),%eax /* same for bpt descriptor */ 960 movw 24(%esi),%ax 961 movl %eax,R(bdb_bpt_ljmp+1) 962 movl 24+2(%esi),%eax 963 movw %ax,R(bdb_bpt_ljmp+5) 964 movl $R(_idt),%edi 965 movl %edi,2(%esp) /* prepare to load kernel idt */ 966 movl $8*4/4,%ecx 967 cld 968 rep /* copy idt */ 969 movsl 970 lidt (%esp) 971 972 addl $6,%esp 973 974bdb_prepare_paging_exit: 975 ret 976 977/* Relocate debugger gdt entries and gdt and idt pointers. */ 978bdb_commit_paging: 979 cmpl $0,_bdb_exists 980 je bdb_commit_paging_exit 981 982 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 983 movl $9,%ecx 984reloc_gdt: 985 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 986 addl $8,%eax /* now KERNBASE>>24 */ 987 loop reloc_gdt 988 989 subl $6,%esp 990 sgdt (%esp) 991 addl $KERNBASE,2(%esp) 992 lgdt (%esp) 993 sidt (%esp) 994 addl $KERNBASE,2(%esp) 995 lidt (%esp) 996 addl $6,%esp 997 998 int $3 999 1000bdb_commit_paging_exit: 1001 ret 1002 1003#endif /* BDE_DEBUGGER */ 1004