locore.s revision 31030
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 1.101 1997/11/04 03:19:25 kato 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#include "opt_vm86.h" 51 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#ifdef SMP 90 .globl _SMP_prvstart 91 .set _SMP_prvstart,(MPPTDI << PDRSHIFT) 92 93 .globl _SMP_prvpage,_SMP_prvpt,_lapic,_SMP_ioapic 94 .globl _prv_CPAGE1,_prv_CPAGE2,_prv_CPAGE3 95 .globl _idlestack,_idlestack_top 96 .set _SMP_prvpage,_SMP_prvstart 97 .set _SMP_prvpt,_SMP_prvstart + PAGE_SIZE 98 .set _lapic,_SMP_prvstart + (2 * PAGE_SIZE) 99 .set _idlestack,_SMP_prvstart + (3 * PAGE_SIZE) 100 .set _idlestack_top,_SMP_prvstart + (( 3 + UPAGES) * PAGE_SIZE) 101 .set _prv_CPAGE1,_SMP_prvstart + ((3 + UPAGES) * PAGE_SIZE) 102 .set _prv_CPAGE2,_SMP_prvstart + ((4 + UPAGES) * PAGE_SIZE) 103 .set _prv_CPAGE3,_SMP_prvstart + ((5 + UPAGES) * PAGE_SIZE) 104 .set _SMP_ioapic,_SMP_prvstart + (16 * PAGE_SIZE) 105 106 .globl _cpuid,_curproc,_curpcb,_npxproc,_runtime,_cpu_lockid 107 .globl _common_tss,_other_cpus,_my_idlePTD,_ss_tpr 108 .globl _prv_CMAP1,_prv_CMAP2,_prv_CMAP3 109 .globl _inside_intr 110 .set _cpuid,_SMP_prvpage+0 /* [0] */ 111 .set _curproc,_SMP_prvpage+4 /* [1] */ 112 .set _curpcb,_SMP_prvpage+8 /* [2] */ 113 .set _npxproc,_SMP_prvpage+12 /* [3] */ 114 .set _runtime,_SMP_prvpage+16 /* [4,5] */ 115 .set _cpu_lockid,_SMP_prvpage+24 /* [6] */ 116 .set _other_cpus,_SMP_prvpage+28 /* [7] bitmap of available CPUs, 117 excluding ourself */ 118 .set _my_idlePTD,_SMP_prvpage+32 /* [8] */ 119 .set _ss_tpr,_SMP_prvpage+36 /* [9] */ 120 .set _prv_CMAP1,_SMP_prvpage+40 /* [10] */ 121 .set _prv_CMAP2,_SMP_prvpage+44 /* [11] */ 122 .set _prv_CMAP3,_SMP_prvpage+48 /* [12] */ 123 .set _inside_intr,_SMP_prvpage+52 /* [13] */ 124 .set _common_tss,_SMP_prvpage+56 /* 102 (ie: 104) bytes long */ 125 126#ifdef VM86 127 .globl _common_tssd 128 .set _common_tssd,_common_tss+104 /* 8 bytes long */ 129 .globl _private_tss 130 .set _private_tss,_common_tss+112 131 .globl _my_tr 132 .set _my_tr,_common_tss+116 133#endif 134 135/* Fetch the .set's for the local apic */ 136#include "i386/i386/mp_apicdefs.s" 137 138#endif 139 140/* 141 * Globals 142 */ 143 .data 144 ALIGN_DATA /* just to be sure */ 145 146 .globl HIDENAME(tmpstk) 147 .space 0x2000 /* space for tmpstk - temporary stack */ 148HIDENAME(tmpstk): 149 150 .globl _boothowto,_bootdev 151 152 .globl _cpu,_cpu_vendor,_cpu_id,_bootinfo 153 .globl _cpu_high, _cpu_feature 154 155_cpu: .long 0 /* are we 386, 386sx, or 486 */ 156_cpu_id: .long 0 /* stepping ID */ 157_cpu_high: .long 0 /* highest arg to CPUID */ 158_cpu_feature: .long 0 /* features */ 159_cpu_vendor: .space 20 /* CPU origin code */ 160_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 161 162_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 163physfree: .long 0 /* phys addr of next free page */ 164 165#ifdef SMP 166cpu0pp: .long 0 /* phys addr cpu0 private pg */ 167cpu0pt: .long 0 /* phys addr cpu0 private pt */ 168 169 .globl _cpu0prvpage,_cpu0prvpt 170_cpu0prvpage: .long 0 /* relocated version */ 171_cpu0prvpt: .long 0 /* relocated version */ 172#endif /* SMP */ 173 174 .globl _IdlePTD 175_IdlePTD: .long 0 /* phys addr of kernel PTD */ 176 177#ifdef SMP 178 .globl _KPTphys 179#endif 180_KPTphys: .long 0 /* phys addr of kernel page tables */ 181 182 .globl _proc0paddr 183_proc0paddr: .long 0 /* address of proc 0 address space */ 184p0upa: .long 0 /* phys addr of proc0's UPAGES */ 185 186#ifdef BDE_DEBUGGER 187 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 188_bdb_exists: .long 0 189#endif 190 191 192/********************************************************************** 193 * 194 * Some handy macros 195 * 196 */ 197 198#define R(foo) ((foo)-KERNBASE) 199 200#define ALLOCPAGES(foo) \ 201 movl R(physfree), %esi ; \ 202 movl $((foo)*PAGE_SIZE), %eax ; \ 203 addl %esi, %eax ; \ 204 movl %eax, R(physfree) ; \ 205 movl %esi, %edi ; \ 206 movl $((foo)*PAGE_SIZE),%ecx ; \ 207 xorl %eax,%eax ; \ 208 cld ; \ 209 rep ; \ 210 stosb 211 212/* 213 * fillkpt 214 * eax = page frame address 215 * ebx = index into page table 216 * ecx = how many pages to map 217 * base = base address of page dir/table 218 * prot = protection bits 219 */ 220#define fillkpt(base, prot) \ 221 shll $2,%ebx ; \ 222 addl base,%ebx ; \ 223 orl $PG_V,%eax ; \ 224 orl prot,%eax ; \ 2251: movl %eax,(%ebx) ; \ 226 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 227 addl $4,%ebx ; /* next pte */ \ 228 loop 1b 229 230/* 231 * fillkptphys(prot) 232 * eax = physical address 233 * ecx = how many pages to map 234 * prot = protection bits 235 */ 236#define fillkptphys(prot) \ 237 movl %eax, %ebx ; \ 238 shrl $PAGE_SHIFT, %ebx ; \ 239 fillkpt(R(_KPTphys), prot) 240 241 .text 242/********************************************************************** 243 * 244 * This is where the bootblocks start us, set the ball rolling... 245 * 246 */ 247NON_GPROF_ENTRY(btext) 248 249#ifdef PC98 250 jmp 1f 251 .globl _pc98_system_parameter 252 .org 0x400 253_pc98_system_parameter: 254 .space 0x240 /* BIOS parameter block */ 2551: 256 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 257 movl $0xa1000,%esi 258 movl $0x100000,%edi 259 movl $0x0630,%ecx 260 cld 261 rep 262 movsb 263#else /* IBM-PC */ 264#ifdef BDE_DEBUGGER 265#ifdef BIOS_STEALS_3K 266 cmpl $0x0375c339,0x95504 267#else 268 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 269#endif 270 jne 1f 271 movb $1,R(_bdb_exists) 2721: 273#endif 274 275/* Tell the bios to warmboot next time */ 276 movw $0x1234,0x472 277#endif /* PC98 */ 278 279/* Set up a real frame in case the double return in newboot is executed. */ 280 pushl %ebp 281 movl %esp, %ebp 282 283/* Don't trust what the BIOS gives for eflags. */ 284 pushl $PSL_KERNEL 285 popfl 286 287/* 288 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 289 * to set %cs, %ds, %es and %ss. 290 */ 291 mov %ds, %ax 292 mov %ax, %fs 293 mov %ax, %gs 294 295 call recover_bootinfo 296 297/* Get onto a stack that we can trust. */ 298/* 299 * XXX this step is delayed in case recover_bootinfo needs to return via 300 * the old stack, but it need not be, since recover_bootinfo actually 301 * returns via the old frame. 302 */ 303 movl $R(HIDENAME(tmpstk)),%esp 304 305#ifdef PC98 306 testb $0x02,0x100620 /* pc98_machine_type & M_EPSON_PC98 */ 307 jz 3f 308 cmpb $0x0b,0x100624 /* epson_machine_id <= 0x0b */ 309 ja 3f 310 311 /* count up memory */ 312 movl $0x100000,%eax /* next, talley remaining memory */ 313 movl $0xFFF-0x100,%ecx 3141: movl 0(%eax),%ebx /* save location to check */ 315 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 316 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 317 jne 2f 318 movl %ebx,0(%eax) /* restore memory */ 319 addl $PAGE_SIZE,%eax 320 loop 1b 3212: subl $0x100000,%eax 322 shrl $17,%eax 323 movb %al,0x100401 3243: 325#endif 326 327 call identify_cpu 328 329/* clear bss */ 330/* 331 * XXX this should be done a little earlier. 332 * 333 * XXX we don't check that there is memory for our bss and page tables 334 * before using it. 335 * 336 * XXX the boot program somewhat bogusly clears the bss. We still have 337 * to do it in case we were unzipped by kzipboot. Then the boot program 338 * only clears kzipboot's bss. 339 * 340 * XXX the gdt and idt are still somewhere in the boot program. We 341 * depend on the convention that the boot program is below 1MB and we 342 * are above 1MB to keep the gdt and idt away from the bss and page 343 * tables. The idt is only used if BDE_DEBUGGER is enabled. 344 */ 345 movl $R(_end),%ecx 346 movl $R(_edata),%edi 347 subl %edi,%ecx 348 xorl %eax,%eax 349 cld 350 rep 351 stosb 352 353#if NAPM > 0 354/* 355 * XXX it's not clear that APM can live in the current environonment. 356 * Only pc-relative addressing works. 357 */ 358 call _apm_setup 359#endif 360 361 call create_pagetables 362 363#ifdef VM86 364/* 365 * If the CPU has support for VME, turn it on. 366 */ 367 testl $CPUID_VME, R(_cpu_feature) 368 jz 1f 369 movl %cr4, %eax 370 orl $CR4_VME, %eax 371 movl %eax, %cr4 3721: 373#endif /* VM86 */ 374 375#ifdef BDE_DEBUGGER 376/* 377 * Adjust as much as possible for paging before enabling paging so that the 378 * adjustments can be traced. 379 */ 380 call bdb_prepare_paging 381#endif 382 383/* Now enable paging */ 384 movl R(_IdlePTD), %eax 385 movl %eax,%cr3 /* load ptd addr into mmu */ 386 movl %cr0,%eax /* get control word */ 387 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 388 movl %eax,%cr0 /* and let's page NOW! */ 389 390#ifdef BDE_DEBUGGER 391/* 392 * Complete the adjustments for paging so that we can keep tracing through 393 * initi386() after the low (physical) addresses for the gdt and idt become 394 * invalid. 395 */ 396 call bdb_commit_paging 397#endif 398 399 pushl $begin /* jump to high virtualized address */ 400 ret 401 402/* now running relocated at KERNBASE where the system is linked to run */ 403begin: 404 /* set up bootstrap stack */ 405 movl _proc0paddr,%esp /* location of in-kernel pages */ 406 addl $UPAGES*PAGE_SIZE,%esp /* bootstrap stack end location */ 407 xorl %eax,%eax /* mark end of frames */ 408 movl %eax,%ebp 409 movl _proc0paddr,%eax 410 movl _IdlePTD, %esi 411 movl %esi,PCB_CR3(%eax) 412 413 movl physfree, %esi 414 pushl %esi /* value of first for init386(first) */ 415 call _init386 /* wire 386 chip for unix operation */ 416 popl %esi 417 418 .globl __ucodesel,__udatasel 419 420 pushl $0 /* unused */ 421 pushl __udatasel /* ss */ 422 pushl $0 /* esp - filled in by execve() */ 423 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 424 pushl __ucodesel /* cs */ 425 pushl $0 /* eip - filled in by execve() */ 426 subl $(12*4),%esp /* space for rest of registers */ 427 428 pushl %esp /* call main with frame pointer */ 429 call _main /* autoconfiguration, mountroot etc */ 430 431 hlt /* never returns to here */ 432 433/* 434 * When starting init, call this to configure the process for user 435 * mode. This will be inherited by other processes. 436 */ 437NON_GPROF_ENTRY(prepare_usermode) 438 /* 439 * Now we've run main() and determined what cpu-type we are, we can 440 * enable write protection and alignment checking on i486 cpus and 441 * above. 442 */ 443#if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU) 444 cmpl $CPUCLASS_386,_cpu_class 445 je 1f 446 movl %cr0,%eax /* get control word */ 447 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 448 movl %eax,%cr0 /* and do it */ 4491: 450#endif 451 /* 452 * on return from main(), we are process 1 453 * set up address space and stack so that we can 'return' to user mode 454 */ 455 movl __ucodesel,%eax 456 movl __udatasel,%ecx 457 458#if 0 459 movl %cx,%ds 460#endif 461 movl %cx,%es 462 movl %ax,%fs /* double map cs to fs */ 463 movl %cx,%gs /* and ds to gs */ 464 ret /* goto user! */ 465 466 467#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 468 469/* 470 * Signal trampoline, copied to top of user stack 471 */ 472NON_GPROF_ENTRY(sigcode) 473 call SIGF_HANDLER(%esp) 474 lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 475 /* copy at 8(%esp)) */ 476 pushl %eax 477 pushl %eax /* junk to fake return address */ 478 movl $SYS_sigreturn,%eax /* sigreturn() */ 479 LCALL(0x7,0) /* enter kernel with args on stack */ 480 hlt /* never gets here */ 481 ALIGN_TEXT 482_esigcode: 483 484 .data 485 .globl _szsigcode 486_szsigcode: 487 .long _esigcode-_sigcode 488 .text 489 490/********************************************************************** 491 * 492 * Recover the bootinfo passed to us from the boot program 493 * 494 */ 495recover_bootinfo: 496 /* 497 * This code is called in different ways depending on what loaded 498 * and started the kernel. This is used to detect how we get the 499 * arguments from the other code and what we do with them. 500 * 501 * Old disk boot blocks: 502 * (*btext)(howto, bootdev, cyloffset, esym); 503 * [return address == 0, and can NOT be returned to] 504 * [cyloffset was not supported by the FreeBSD boot code 505 * and always passed in as 0] 506 * [esym is also known as total in the boot code, and 507 * was never properly supported by the FreeBSD boot code] 508 * 509 * Old diskless netboot code: 510 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 511 * [return address != 0, and can NOT be returned to] 512 * If we are being booted by this code it will NOT work, 513 * so we are just going to halt if we find this case. 514 * 515 * New uniform boot code: 516 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 517 * [return address != 0, and can be returned to] 518 * 519 * There may seem to be a lot of wasted arguments in here, but 520 * that is so the newer boot code can still load very old kernels 521 * and old boot code can load new kernels. 522 */ 523 524 /* 525 * The old style disk boot blocks fake a frame on the stack and 526 * did an lret to get here. The frame on the stack has a return 527 * address of 0. 528 */ 529 cmpl $0,4(%ebp) 530 je olddiskboot 531 532 /* 533 * We have some form of return address, so this is either the 534 * old diskless netboot code, or the new uniform code. That can 535 * be detected by looking at the 5th argument, if it is 0 536 * we are being booted by the new uniform boot code. 537 */ 538 cmpl $0,24(%ebp) 539 je newboot 540 541 /* 542 * Seems we have been loaded by the old diskless boot code, we 543 * don't stand a chance of running as the diskless structure 544 * changed considerably between the two, so just halt. 545 */ 546 hlt 547 548 /* 549 * We have been loaded by the new uniform boot code. 550 * Let's check the bootinfo version, and if we do not understand 551 * it we return to the loader with a status of 1 to indicate this error 552 */ 553newboot: 554 movl 28(%ebp),%ebx /* &bootinfo.version */ 555 movl BI_VERSION(%ebx),%eax 556 cmpl $1,%eax /* We only understand version 1 */ 557 je 1f 558 movl $1,%eax /* Return status */ 559 leave 560 /* 561 * XXX this returns to our caller's caller (as is required) since 562 * we didn't set up a frame and our caller did. 563 */ 564 ret 565 5661: 567 /* 568 * If we have a kernelname copy it in 569 */ 570 movl BI_KERNELNAME(%ebx),%esi 571 cmpl $0,%esi 572 je 2f /* No kernelname */ 573 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 574 movl $R(_kernelname),%edi 575 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 576 je 1f 577 movb $'/',(%edi) 578 incl %edi 579 decl %ecx 5801: 581 cld 582 rep 583 movsb 584 5852: 586 /* 587 * Determine the size of the boot loader's copy of the bootinfo 588 * struct. This is impossible to do properly because old versions 589 * of the struct don't contain a size field and there are 2 old 590 * versions with the same version number. 591 */ 592 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 593 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 594 je got_bi_size /* no, sizeless version */ 595 movl BI_SIZE(%ebx),%ecx 596got_bi_size: 597 598 /* 599 * Copy the common part of the bootinfo struct 600 */ 601 movl %ebx,%esi 602 movl $R(_bootinfo),%edi 603 cmpl $BOOTINFO_SIZE,%ecx 604 jbe got_common_bi_size 605 movl $BOOTINFO_SIZE,%ecx 606got_common_bi_size: 607 cld 608 rep 609 movsb 610 611#ifdef NFS 612#ifndef BOOTP_NFSV3 613 /* 614 * If we have a nfs_diskless structure copy it in 615 */ 616 movl BI_NFS_DISKLESS(%ebx),%esi 617 cmpl $0,%esi 618 je olddiskboot 619 movl $R(_nfs_diskless),%edi 620 movl $NFSDISKLESS_SIZE,%ecx 621 cld 622 rep 623 movsb 624 movl $R(_nfs_diskless_valid),%edi 625 movl $1,(%edi) 626#endif 627#endif 628 629 /* 630 * The old style disk boot. 631 * (*btext)(howto, bootdev, cyloffset, esym); 632 * Note that the newer boot code just falls into here to pick 633 * up howto and bootdev, cyloffset and esym are no longer used 634 */ 635olddiskboot: 636 movl 8(%ebp),%eax 637 movl %eax,R(_boothowto) 638 movl 12(%ebp),%eax 639 movl %eax,R(_bootdev) 640 641#if defined(USERCONFIG_BOOT) && defined(USERCONFIG) 642 movl $0x10200, %esi 643 movl $R(_userconfig_from_boot),%edi 644 movl $512,%ecx 645 cld 646 rep 647 movsb 648#endif /* USERCONFIG_BOOT */ 649 650 ret 651 652 653/********************************************************************** 654 * 655 * Identify the CPU and initialize anything special about it 656 * 657 */ 658identify_cpu: 659 660 /* Try to toggle alignment check flag; does not exist on 386. */ 661 pushfl 662 popl %eax 663 movl %eax,%ecx 664 orl $PSL_AC,%eax 665 pushl %eax 666 popfl 667 pushfl 668 popl %eax 669 xorl %ecx,%eax 670 andl $PSL_AC,%eax 671 pushl %ecx 672 popfl 673 674 testl %eax,%eax 675 jnz try486 676 677 /* NexGen CPU does not have aligment check flag. */ 678 pushfl 679 movl $0x5555, %eax 680 xorl %edx, %edx 681 movl $2, %ecx 682 clc 683 divl %ecx 684 jz trynexgen 685 popfl 686 movl $CPU_386,R(_cpu) 687 jmp 3f 688 689trynexgen: 690 popfl 691 movl $CPU_NX586,R(_cpu) 692 movl $0x4778654e,R(_cpu_vendor) # store vendor string 693 movl $0x72446e65,R(_cpu_vendor+4) 694 movl $0x6e657669,R(_cpu_vendor+8) 695 movl $0,R(_cpu_vendor+12) 696 jmp 3f 697 698try486: /* Try to toggle identification flag; does not exist on early 486s. */ 699 pushfl 700 popl %eax 701 movl %eax,%ecx 702 xorl $PSL_ID,%eax 703 pushl %eax 704 popfl 705 pushfl 706 popl %eax 707 xorl %ecx,%eax 708 andl $PSL_ID,%eax 709 pushl %ecx 710 popfl 711 712 testl %eax,%eax 713 jnz trycpuid 714 movl $CPU_486,R(_cpu) 715 716 /* 717 * Check Cyrix CPU 718 * Cyrix CPUs do not change the undefined flags following 719 * execution of the divide instruction which divides 5 by 2. 720 * 721 * Note: CPUID is enabled on M2, so it passes another way. 722 */ 723 pushfl 724 movl $0x5555, %eax 725 xorl %edx, %edx 726 movl $2, %ecx 727 clc 728 divl %ecx 729 jnc trycyrix 730 popfl 731 jmp 3f /* You may use Intel CPU. */ 732 733trycyrix: 734 popfl 735 /* 736 * IBM Bluelighting CPU also doesn't change the undefined flags. 737 * Because IBM doesn't disclose the information for Bluelighting 738 * CPU, we couldn't distinguish it from Cyrix's (including IBM 739 * brand of Cyrix CPUs). 740 */ 741 movl $0x69727943,R(_cpu_vendor) # store vendor string 742 movl $0x736e4978,R(_cpu_vendor+4) 743 movl $0x64616574,R(_cpu_vendor+8) 744 jmp 3f 745 746trycpuid: /* Use the `cpuid' instruction. */ 747 xorl %eax,%eax 748 .byte 0x0f,0xa2 # cpuid 0 749 movl %eax,R(_cpu_high) # highest capability 750 movl %ebx,R(_cpu_vendor) # store vendor string 751 movl %edx,R(_cpu_vendor+4) 752 movl %ecx,R(_cpu_vendor+8) 753 movb $0,R(_cpu_vendor+12) 754 755 movl $1,%eax 756 .byte 0x0f,0xa2 # cpuid 1 757 movl %eax,R(_cpu_id) # store cpu_id 758 movl %edx,R(_cpu_feature) # store cpu_feature 759 rorl $8,%eax # extract family type 760 andl $15,%eax 761 cmpl $5,%eax 762 jae 1f 763 764 /* less than Pentium; must be 486 */ 765 movl $CPU_486,R(_cpu) 766 jmp 3f 7671: 768 /* a Pentium? */ 769 cmpl $5,%eax 770 jne 2f 771 movl $CPU_586,R(_cpu) 772 jmp 3f 7732: 774 /* Greater than Pentium...call it a Pentium Pro */ 775 movl $CPU_686,R(_cpu) 7763: 777 ret 778 779 780/********************************************************************** 781 * 782 * Create the first page directory and its page tables. 783 * 784 */ 785 786create_pagetables: 787 788 testl $CPUID_PGE, R(_cpu_feature) 789 jz 1f 790 movl %cr4, %eax 791 orl $CR4_PGE, %eax 792 movl %eax, %cr4 7931: 794 795/* Find end of kernel image (rounded up to a page boundary). */ 796 movl $R(_end),%esi 797 798/* include symbols in "kernel image" if they are loaded and useful */ 799#ifdef DDB 800 movl R(_bootinfo+BI_ESYMTAB),%edi 801 testl %edi,%edi 802 je over_symalloc 803 movl %edi,%esi 804 movl $KERNBASE,%edi 805 addl %edi,R(_bootinfo+BI_SYMTAB) 806 addl %edi,R(_bootinfo+BI_ESYMTAB) 807over_symalloc: 808#endif 809 810 addl $PAGE_MASK,%esi 811 andl $~PAGE_MASK,%esi 812 movl %esi,R(_KERNend) /* save end of kernel */ 813 movl %esi,R(physfree) /* next free page is at end of kernel */ 814 815/* Allocate Kernel Page Tables */ 816 ALLOCPAGES(NKPT) 817 movl %esi,R(_KPTphys) 818 819/* Allocate Page Table Directory */ 820 ALLOCPAGES(1) 821 movl %esi,R(_IdlePTD) 822 823/* Allocate UPAGES */ 824 ALLOCPAGES(UPAGES) 825 movl %esi,R(p0upa) 826 addl $KERNBASE, %esi 827 movl %esi, R(_proc0paddr) 828 829#ifdef SMP 830/* Allocate cpu0's private data page */ 831 ALLOCPAGES(1) 832 movl %esi,R(cpu0pp) 833 addl $KERNBASE, %esi 834 movl %esi, R(_cpu0prvpage) /* relocated to KVM space */ 835 836/* Allocate cpu0's private page table for mapping priv page, apic, etc */ 837 ALLOCPAGES(1) 838 movl %esi,R(cpu0pt) 839 addl $KERNBASE, %esi 840 movl %esi, R(_cpu0prvpt) /* relocated to KVM space */ 841#endif /* SMP */ 842 843/* Map read-only from zero to the end of the kernel text section */ 844 xorl %eax, %eax 845#ifdef BDE_DEBUGGER 846/* If the debugger is present, actually map everything read-write. */ 847 cmpl $0,R(_bdb_exists) 848 jne map_read_write 849#endif 850 xorl %edx,%edx 851 852#if !defined(SMP) 853 testl $CPUID_PGE, R(_cpu_feature) 854 jz 2f 855 orl $PG_G,%edx 856#endif 857 8582: movl $R(_etext),%ecx 859 addl $PAGE_MASK,%ecx 860 shrl $PAGE_SHIFT,%ecx 861 fillkptphys(%edx) 862 863/* Map read-write, data, bss and symbols */ 864 movl $R(_etext),%eax 865 addl $PAGE_MASK, %eax 866 andl $~PAGE_MASK, %eax 867map_read_write: 868 movl $PG_RW,%edx 869#if !defined(SMP) 870 testl $CPUID_PGE, R(_cpu_feature) 871 jz 1f 872 orl $PG_G,%edx 873#endif 874 8751: movl R(_KERNend),%ecx 876 subl %eax,%ecx 877 shrl $PAGE_SHIFT,%ecx 878 fillkptphys(%edx) 879 880/* Map page directory. */ 881 movl R(_IdlePTD), %eax 882 movl $1, %ecx 883 fillkptphys($PG_RW) 884 885/* Map proc0's UPAGES in the physical way ... */ 886 movl R(p0upa), %eax 887 movl $UPAGES, %ecx 888 fillkptphys($PG_RW) 889 890/* Map ISA hole */ 891 movl $ISA_HOLE_START, %eax 892 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 893 fillkptphys($PG_RW) 894 895#ifdef SMP 896/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 897 movl R(cpu0pp), %eax 898 movl $1, %ecx 899 fillkptphys($PG_RW) 900 901/* Map cpu0's private page table into global kmem FWIW */ 902 movl R(cpu0pt), %eax 903 movl $1, %ecx 904 fillkptphys($PG_RW) 905 906/* Map the private page into the private page table into private space */ 907 movl R(cpu0pp), %eax 908 movl $0, %ebx /* pte offset = 0 */ 909 movl $1, %ecx /* one private page coming right up */ 910 fillkpt(R(cpu0pt), $PG_RW) 911 912/* Map the page table page into private space */ 913 movl R(cpu0pt), %eax 914 movl $1, %ebx /* pte offset = 1 */ 915 movl $1, %ecx /* one private pt coming right up */ 916 fillkpt(R(cpu0pt), $PG_RW) 917 918/* ... and put the page table table in the pde. */ 919 movl R(cpu0pt), %eax 920 movl $MPPTDI, %ebx 921 movl $1, %ecx 922 fillkpt(R(_IdlePTD), $PG_RW) 923#endif /* SMP */ 924 925/* install a pde for temporary double map of bottom of VA */ 926 movl R(_KPTphys), %eax 927 xorl %ebx, %ebx 928 movl $1, %ecx 929 fillkpt(R(_IdlePTD), $PG_RW) 930 931/* install pde's for pt's */ 932 movl R(_KPTphys), %eax 933 movl $KPTDI, %ebx 934 movl $NKPT, %ecx 935 fillkpt(R(_IdlePTD), $PG_RW) 936 937/* install a pde recursively mapping page directory as a page table */ 938 movl R(_IdlePTD), %eax 939 movl $PTDPTDI, %ebx 940 movl $1,%ecx 941 fillkpt(R(_IdlePTD), $PG_RW) 942 943 ret 944 945#ifdef BDE_DEBUGGER 946bdb_prepare_paging: 947 cmpl $0,R(_bdb_exists) 948 je bdb_prepare_paging_exit 949 950 subl $6,%esp 951 952 /* 953 * Copy and convert debugger entries from the bootstrap gdt and idt 954 * to the kernel gdt and idt. Everything is still in low memory. 955 * Tracing continues to work after paging is enabled because the 956 * low memory addresses remain valid until everything is relocated. 957 * However, tracing through the setidt() that initializes the trace 958 * trap will crash. 959 */ 960 sgdt (%esp) 961 movl 2(%esp),%esi /* base address of bootstrap gdt */ 962 movl $R(_gdt),%edi 963 movl %edi,2(%esp) /* prepare to load kernel gdt */ 964 movl $8*18/4,%ecx 965 cld 966 rep /* copy gdt */ 967 movsl 968 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 969 movb $0x92,-8+5(%edi) 970 lgdt (%esp) 971 972 sidt (%esp) 973 movl 2(%esp),%esi /* base address of current idt */ 974 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 975 movw 8(%esi),%ax 976 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 977 movl 8+2(%esi),%eax 978 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 979 movl 24+4(%esi),%eax /* same for bpt descriptor */ 980 movw 24(%esi),%ax 981 movl %eax,R(bdb_bpt_ljmp+1) 982 movl 24+2(%esi),%eax 983 movw %ax,R(bdb_bpt_ljmp+5) 984 movl $R(_idt),%edi 985 movl %edi,2(%esp) /* prepare to load kernel idt */ 986 movl $8*4/4,%ecx 987 cld 988 rep /* copy idt */ 989 movsl 990 lidt (%esp) 991 992 addl $6,%esp 993 994bdb_prepare_paging_exit: 995 ret 996 997/* Relocate debugger gdt entries and gdt and idt pointers. */ 998bdb_commit_paging: 999 cmpl $0,_bdb_exists 1000 je bdb_commit_paging_exit 1001 1002 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 1003 movl $9,%ecx 1004reloc_gdt: 1005 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 1006 addl $8,%eax /* now KERNBASE>>24 */ 1007 loop reloc_gdt 1008 1009 subl $6,%esp 1010 sgdt (%esp) 1011 addl $KERNBASE,2(%esp) 1012 lgdt (%esp) 1013 sidt (%esp) 1014 addl $KERNBASE,2(%esp) 1015 lidt (%esp) 1016 addl $6,%esp 1017 1018 int $3 1019 1020bdb_commit_paging_exit: 1021 ret 1022 1023#endif /* BDE_DEBUGGER */ 1024