locore.s revision 29213
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 1.5 1997/09/02 04:38:32 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 .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 + (4 * PAGE_SIZE) 100 .set _prv_CPAGE1,_SMP_prvstart + (4 * PAGE_SIZE) 101 .set _prv_CPAGE2,_SMP_prvstart + (5 * PAGE_SIZE) 102 .set _prv_CPAGE3,_SMP_prvstart + (6 * 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/* Fetch the .set's for the local apic */ 126#include "i386/i386/mp_apicdefs.s" 127 128#endif 129 130/* 131 * Globals 132 */ 133 .data 134 ALIGN_DATA /* just to be sure */ 135 136 .globl HIDENAME(tmpstk) 137 .space 0x2000 /* space for tmpstk - temporary stack */ 138HIDENAME(tmpstk): 139 140 .globl _boothowto,_bootdev 141 142 .globl _cpu,_cpu_vendor,_cpu_id,_bootinfo 143 .globl _cpu_high, _cpu_feature 144 145_cpu: .long 0 /* are we 386, 386sx, or 486 */ 146_cpu_id: .long 0 /* stepping ID */ 147_cpu_high: .long 0 /* highest arg to CPUID */ 148_cpu_feature: .long 0 /* features */ 149_cpu_vendor: .space 20 /* CPU origin code */ 150_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 151 152_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 153physfree: .long 0 /* phys addr of next free page */ 154 155#ifdef SMP 156cpu0pp: .long 0 /* phys addr cpu0 private pg */ 157cpu0pt: .long 0 /* phys addr cpu0 private pt */ 158 159 .globl _cpu0prvpage,_cpu0prvpt 160_cpu0prvpage: .long 0 /* relocated version */ 161_cpu0prvpt: .long 0 /* relocated version */ 162#endif /* SMP */ 163 164 .globl _IdlePTD 165_IdlePTD: .long 0 /* phys addr of kernel PTD */ 166 167#ifdef SMP 168 .globl _KPTphys 169#endif 170_KPTphys: .long 0 /* phys addr of kernel page tables */ 171 172 .globl _proc0paddr 173_proc0paddr: .long 0 /* address of proc 0 address space */ 174p0upa: .long 0 /* phys addr of proc0's UPAGES */ 175 176#ifdef BDE_DEBUGGER 177 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 178_bdb_exists: .long 0 179#endif 180 181 182/********************************************************************** 183 * 184 * Some handy macros 185 * 186 */ 187 188#define R(foo) ((foo)-KERNBASE) 189 190#define ALLOCPAGES(foo) \ 191 movl R(physfree), %esi ; \ 192 movl $((foo)*PAGE_SIZE), %eax ; \ 193 addl %esi, %eax ; \ 194 movl %eax, R(physfree) ; \ 195 movl %esi, %edi ; \ 196 movl $((foo)*PAGE_SIZE),%ecx ; \ 197 xorl %eax,%eax ; \ 198 cld ; \ 199 rep ; \ 200 stosb 201 202/* 203 * fillkpt 204 * eax = page frame address 205 * ebx = index into page table 206 * ecx = how many pages to map 207 * base = base address of page dir/table 208 * prot = protection bits 209 */ 210#define fillkpt(base, prot) \ 211 shll $2,%ebx ; \ 212 addl base,%ebx ; \ 213 orl $PG_V,%eax ; \ 214 orl prot,%eax ; \ 2151: movl %eax,(%ebx) ; \ 216 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 217 addl $4,%ebx ; /* next pte */ \ 218 loop 1b 219 220/* 221 * fillkptphys(prot) 222 * eax = physical address 223 * ecx = how many pages to map 224 * prot = protection bits 225 */ 226#define fillkptphys(prot) \ 227 movl %eax, %ebx ; \ 228 shrl $PAGE_SHIFT, %ebx ; \ 229 fillkpt(R(_KPTphys), prot) 230 231 .text 232/********************************************************************** 233 * 234 * This is where the bootblocks start us, set the ball rolling... 235 * 236 */ 237NON_GPROF_ENTRY(btext) 238 239#ifdef PC98 240 jmp 1f 241 .globl _pc98_system_parameter 242 .org 0x400 243_pc98_system_parameter: 244 .space 0x240 /* BIOS parameter block */ 2451: 246 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 247 movl $0xa1000,%esi 248 movl $0x100000,%edi 249 movl $0x0630,%ecx 250 cld 251 rep 252 movsb 253#else /* IBM-PC */ 254#ifdef BDE_DEBUGGER 255#ifdef BIOS_STEALS_3K 256 cmpl $0x0375c339,0x95504 257#else 258 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 259#endif 260 jne 1f 261 movb $1,R(_bdb_exists) 2621: 263#endif 264 265/* Tell the bios to warmboot next time */ 266 movw $0x1234,0x472 267#endif /* PC98 */ 268 269/* Set up a real frame in case the double return in newboot is executed. */ 270 pushl %ebp 271 movl %esp, %ebp 272 273/* Don't trust what the BIOS gives for eflags. */ 274 pushl $PSL_KERNEL 275 popfl 276 277/* 278 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 279 * to set %cs, %ds, %es and %ss. 280 */ 281 mov %ds, %ax 282 mov %ax, %fs 283 mov %ax, %gs 284 285 call recover_bootinfo 286 287/* Get onto a stack that we can trust. */ 288/* 289 * XXX this step is delayed in case recover_bootinfo needs to return via 290 * the old stack, but it need not be, since recover_bootinfo actually 291 * returns via the old frame. 292 */ 293 movl $R(HIDENAME(tmpstk)),%esp 294 295#ifdef PC98 296 testb $0x02,0x100620 /* pc98_machine_type & M_EPSON_PC98 */ 297 jz 3f 298 cmpb $0x0b,0x100624 /* epson_machine_id <= 0x0b */ 299 ja 3f 300 301 /* count up memory */ 302 movl $0x100000,%eax /* next, talley remaining memory */ 303 movl $0xFFF-0x100,%ecx 3041: movl 0(%eax),%ebx /* save location to check */ 305 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 306 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 307 jne 2f 308 movl %ebx,0(%eax) /* restore memory */ 309 addl $PAGE_SIZE,%eax 310 loop 1b 3112: subl $0x100000,%eax 312 shrl $17,%eax 313 movb %al,0x100401 3143: 315#endif 316 317 call identify_cpu 318 319/* clear bss */ 320/* 321 * XXX this should be done a little earlier. 322 * 323 * XXX we don't check that there is memory for our bss and page tables 324 * before using it. 325 * 326 * XXX the boot program somewhat bogusly clears the bss. We still have 327 * to do it in case we were unzipped by kzipboot. Then the boot program 328 * only clears kzipboot's bss. 329 * 330 * XXX the gdt and idt are still somewhere in the boot program. We 331 * depend on the convention that the boot program is below 1MB and we 332 * are above 1MB to keep the gdt and idt away from the bss and page 333 * tables. The idt is only used if BDE_DEBUGGER is enabled. 334 */ 335 movl $R(_end),%ecx 336 movl $R(_edata),%edi 337 subl %edi,%ecx 338 xorl %eax,%eax 339 cld 340 rep 341 stosb 342 343#if NAPM > 0 344/* 345 * XXX it's not clear that APM can live in the current environonment. 346 * Only pc-relative addressing works. 347 */ 348 call _apm_setup 349#endif 350 351 call create_pagetables 352 353#ifdef VM86 354/* 355 * If the CPU has support for VME, turn it on. 356 */ 357 testl $CPUID_VME, R(_cpu_feature) 358 jz 1f 359 movl %cr4, %eax 360 orl $CR4_VME, %eax 361 movl %eax, %cr4 3621: 363#endif /* VM86 */ 364 365#ifdef BDE_DEBUGGER 366/* 367 * Adjust as much as possible for paging before enabling paging so that the 368 * adjustments can be traced. 369 */ 370 call bdb_prepare_paging 371#endif 372 373/* Now enable paging */ 374 movl R(_IdlePTD), %eax 375 movl %eax,%cr3 /* load ptd addr into mmu */ 376 movl %cr0,%eax /* get control word */ 377 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 378 movl %eax,%cr0 /* and let's page NOW! */ 379 380#ifdef BDE_DEBUGGER 381/* 382 * Complete the adjustments for paging so that we can keep tracing through 383 * initi386() after the low (physical) addresses for the gdt and idt become 384 * invalid. 385 */ 386 call bdb_commit_paging 387#endif 388 389 pushl $begin /* jump to high virtualized address */ 390 ret 391 392/* now running relocated at KERNBASE where the system is linked to run */ 393begin: 394 /* set up bootstrap stack */ 395 movl _proc0paddr,%esp /* location of in-kernel pages */ 396 addl $UPAGES*PAGE_SIZE,%esp /* bootstrap stack end location */ 397 xorl %eax,%eax /* mark end of frames */ 398 movl %eax,%ebp 399 movl _proc0paddr,%eax 400 movl _IdlePTD, %esi 401 movl %esi,PCB_CR3(%eax) 402 403 movl physfree, %esi 404 pushl %esi /* value of first for init386(first) */ 405 call _init386 /* wire 386 chip for unix operation */ 406 popl %esi 407 408 .globl __ucodesel,__udatasel 409 410 pushl $0 /* unused */ 411 pushl __udatasel /* ss */ 412 pushl $0 /* esp - filled in by execve() */ 413 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 414 pushl __ucodesel /* cs */ 415 pushl $0 /* eip - filled in by execve() */ 416 subl $(12*4),%esp /* space for rest of registers */ 417 418 pushl %esp /* call main with frame pointer */ 419 call _main /* autoconfiguration, mountroot etc */ 420 421 hlt /* never returns to here */ 422 423/* 424 * When starting init, call this to configure the process for user 425 * mode. This will be inherited by other processes. 426 */ 427NON_GPROF_ENTRY(prepare_usermode) 428 /* 429 * Now we've run main() and determined what cpu-type we are, we can 430 * enable write protection and alignment checking on i486 cpus and 431 * above. 432 */ 433#if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU) 434 cmpl $CPUCLASS_386,_cpu_class 435 je 1f 436 movl %cr0,%eax /* get control word */ 437 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 438 movl %eax,%cr0 /* and do it */ 4391: 440#endif 441 /* 442 * on return from main(), we are process 1 443 * set up address space and stack so that we can 'return' to user mode 444 */ 445 movl __ucodesel,%eax 446 movl __udatasel,%ecx 447 448#if 0 449 movl %cx,%ds 450#endif 451 movl %cx,%es 452 movl %ax,%fs /* double map cs to fs */ 453 movl %cx,%gs /* and ds to gs */ 454 ret /* goto user! */ 455 456 457#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 458 459/* 460 * Signal trampoline, copied to top of user stack 461 */ 462NON_GPROF_ENTRY(sigcode) 463 call SIGF_HANDLER(%esp) 464 lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 465 /* copy at 8(%esp)) */ 466 pushl %eax 467 pushl %eax /* junk to fake return address */ 468 movl $SYS_sigreturn,%eax /* sigreturn() */ 469 LCALL(0x7,0) /* enter kernel with args on stack */ 470 hlt /* never gets here */ 471 ALIGN_TEXT 472_esigcode: 473 474 .data 475 .globl _szsigcode 476_szsigcode: 477 .long _esigcode-_sigcode 478 .text 479 480/********************************************************************** 481 * 482 * Recover the bootinfo passed to us from the boot program 483 * 484 */ 485recover_bootinfo: 486 /* 487 * This code is called in different ways depending on what loaded 488 * and started the kernel. This is used to detect how we get the 489 * arguments from the other code and what we do with them. 490 * 491 * Old disk boot blocks: 492 * (*btext)(howto, bootdev, cyloffset, esym); 493 * [return address == 0, and can NOT be returned to] 494 * [cyloffset was not supported by the FreeBSD boot code 495 * and always passed in as 0] 496 * [esym is also known as total in the boot code, and 497 * was never properly supported by the FreeBSD boot code] 498 * 499 * Old diskless netboot code: 500 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 501 * [return address != 0, and can NOT be returned to] 502 * If we are being booted by this code it will NOT work, 503 * so we are just going to halt if we find this case. 504 * 505 * New uniform boot code: 506 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 507 * [return address != 0, and can be returned to] 508 * 509 * There may seem to be a lot of wasted arguments in here, but 510 * that is so the newer boot code can still load very old kernels 511 * and old boot code can load new kernels. 512 */ 513 514 /* 515 * The old style disk boot blocks fake a frame on the stack and 516 * did an lret to get here. The frame on the stack has a return 517 * address of 0. 518 */ 519 cmpl $0,4(%ebp) 520 je olddiskboot 521 522 /* 523 * We have some form of return address, so this is either the 524 * old diskless netboot code, or the new uniform code. That can 525 * be detected by looking at the 5th argument, if it is 0 526 * we are being booted by the new uniform boot code. 527 */ 528 cmpl $0,24(%ebp) 529 je newboot 530 531 /* 532 * Seems we have been loaded by the old diskless boot code, we 533 * don't stand a chance of running as the diskless structure 534 * changed considerably between the two, so just halt. 535 */ 536 hlt 537 538 /* 539 * We have been loaded by the new uniform boot code. 540 * Let's check the bootinfo version, and if we do not understand 541 * it we return to the loader with a status of 1 to indicate this error 542 */ 543newboot: 544 movl 28(%ebp),%ebx /* &bootinfo.version */ 545 movl BI_VERSION(%ebx),%eax 546 cmpl $1,%eax /* We only understand version 1 */ 547 je 1f 548 movl $1,%eax /* Return status */ 549 leave 550 /* 551 * XXX this returns to our caller's caller (as is required) since 552 * we didn't set up a frame and our caller did. 553 */ 554 ret 555 5561: 557 /* 558 * If we have a kernelname copy it in 559 */ 560 movl BI_KERNELNAME(%ebx),%esi 561 cmpl $0,%esi 562 je 2f /* No kernelname */ 563 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 564 movl $R(_kernelname),%edi 565 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 566 je 1f 567 movb $'/',(%edi) 568 incl %edi 569 decl %ecx 5701: 571 cld 572 rep 573 movsb 574 5752: 576 /* 577 * Determine the size of the boot loader's copy of the bootinfo 578 * struct. This is impossible to do properly because old versions 579 * of the struct don't contain a size field and there are 2 old 580 * versions with the same version number. 581 */ 582 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 583 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 584 je got_bi_size /* no, sizeless version */ 585 movl BI_SIZE(%ebx),%ecx 586got_bi_size: 587 588 /* 589 * Copy the common part of the bootinfo struct 590 */ 591 movl %ebx,%esi 592 movl $R(_bootinfo),%edi 593 cmpl $BOOTINFO_SIZE,%ecx 594 jbe got_common_bi_size 595 movl $BOOTINFO_SIZE,%ecx 596got_common_bi_size: 597 cld 598 rep 599 movsb 600 601#ifdef NFS 602#ifndef BOOTP_NFSV3 603 /* 604 * If we have a nfs_diskless structure copy it in 605 */ 606 movl BI_NFS_DISKLESS(%ebx),%esi 607 cmpl $0,%esi 608 je olddiskboot 609 movl $R(_nfs_diskless),%edi 610 movl $NFSDISKLESS_SIZE,%ecx 611 cld 612 rep 613 movsb 614 movl $R(_nfs_diskless_valid),%edi 615 movl $1,(%edi) 616#endif 617#endif 618 619 /* 620 * The old style disk boot. 621 * (*btext)(howto, bootdev, cyloffset, esym); 622 * Note that the newer boot code just falls into here to pick 623 * up howto and bootdev, cyloffset and esym are no longer used 624 */ 625olddiskboot: 626 movl 8(%ebp),%eax 627 movl %eax,R(_boothowto) 628 movl 12(%ebp),%eax 629 movl %eax,R(_bootdev) 630 631#if defined(USERCONFIG_BOOT) && defined(USERCONFIG) 632#ifdef PC98 633 movl $0x90200, %esi 634#else 635 movl $0x10200, %esi 636#endif 637 movl $R(_userconfig_from_boot),%edi 638 movl $512,%ecx 639 cld 640 rep 641 movsb 642#endif /* USERCONFIG_BOOT */ 643 644 ret 645 646 647/********************************************************************** 648 * 649 * Identify the CPU and initialize anything special about it 650 * 651 */ 652identify_cpu: 653 654 /* Try to toggle alignment check flag; does not exist on 386. */ 655 pushfl 656 popl %eax 657 movl %eax,%ecx 658 orl $PSL_AC,%eax 659 pushl %eax 660 popfl 661 pushfl 662 popl %eax 663 xorl %ecx,%eax 664 andl $PSL_AC,%eax 665 pushl %ecx 666 popfl 667 668 testl %eax,%eax 669 jnz try486 670 671 /* NexGen CPU does not have aligment check flag. */ 672 pushfl 673 movl $0x5555, %eax 674 xorl %edx, %edx 675 movl $2, %ecx 676 clc 677 divl %ecx 678 jz trynexgen 679 popfl 680 movl $CPU_386,R(_cpu) 681 jmp 3f 682 683trynexgen: 684 popfl 685 movl $CPU_NX586,R(_cpu) 686 movl $0x4778654e,R(_cpu_vendor) # store vendor string 687 movl $0x72446e65,R(_cpu_vendor+4) 688 movl $0x6e657669,R(_cpu_vendor+8) 689 movl $0,R(_cpu_vendor+12) 690 jmp 3f 691 692try486: /* Try to toggle identification flag; does not exist on early 486s. */ 693 pushfl 694 popl %eax 695 movl %eax,%ecx 696 xorl $PSL_ID,%eax 697 pushl %eax 698 popfl 699 pushfl 700 popl %eax 701 xorl %ecx,%eax 702 andl $PSL_ID,%eax 703 pushl %ecx 704 popfl 705 706 testl %eax,%eax 707 jnz trycpuid 708 movl $CPU_486,R(_cpu) 709 710 /* 711 * Check Cyrix CPU 712 * Cyrix CPUs do not change the undefined flags following 713 * execution of the divide instruction which divides 5 by 2. 714 * 715 * Note: CPUID is enabled on M2, so it passes another way. 716 */ 717 pushfl 718 movl $0x5555, %eax 719 xorl %edx, %edx 720 movl $2, %ecx 721 clc 722 divl %ecx 723 jnc trycyrix 724 popfl 725 jmp 3f /* You may use Intel CPU. */ 726 727trycyrix: 728 popfl 729 /* 730 * IBM Bluelighting CPU also doesn't change the undefined flags. 731 * Because IBM doesn't disclose the information for Bluelighting 732 * CPU, we couldn't distinguish it from Cyrix's (including IBM 733 * brand of Cyrix CPUs). 734 */ 735 movl $0x69727943,R(_cpu_vendor) # store vendor string 736 movl $0x736e4978,R(_cpu_vendor+4) 737 movl $0x64616574,R(_cpu_vendor+8) 738 jmp 3f 739 740trycpuid: /* Use the `cpuid' instruction. */ 741 xorl %eax,%eax 742 .byte 0x0f,0xa2 # cpuid 0 743 movl %eax,R(_cpu_high) # highest capability 744 movl %ebx,R(_cpu_vendor) # store vendor string 745 movl %edx,R(_cpu_vendor+4) 746 movl %ecx,R(_cpu_vendor+8) 747 movb $0,R(_cpu_vendor+12) 748 749 movl $1,%eax 750 .byte 0x0f,0xa2 # cpuid 1 751 movl %eax,R(_cpu_id) # store cpu_id 752 movl %edx,R(_cpu_feature) # store cpu_feature 753 rorl $8,%eax # extract family type 754 andl $15,%eax 755 cmpl $5,%eax 756 jae 1f 757 758 /* less than Pentium; must be 486 */ 759 movl $CPU_486,R(_cpu) 760 jmp 3f 7611: 762 /* a Pentium? */ 763 cmpl $5,%eax 764 jne 2f 765 movl $CPU_586,R(_cpu) 766 jmp 3f 7672: 768 /* Greater than Pentium...call it a Pentium Pro */ 769 movl $CPU_686,R(_cpu) 7703: 771 ret 772 773 774/********************************************************************** 775 * 776 * Create the first page directory and its page tables. 777 * 778 */ 779 780create_pagetables: 781 782 testl $CPUID_PGE, R(_cpu_feature) 783 jz 1f 784 movl %cr4, %eax 785 orl $CR4_PGE, %eax 786 movl %eax, %cr4 7871: 788 789/* Find end of kernel image (rounded up to a page boundary). */ 790 movl $R(_end),%esi 791 792/* include symbols in "kernel image" if they are loaded and useful */ 793#ifdef DDB 794 movl R(_bootinfo+BI_ESYMTAB),%edi 795 testl %edi,%edi 796 je over_symalloc 797 movl %edi,%esi 798 movl $KERNBASE,%edi 799 addl %edi,R(_bootinfo+BI_SYMTAB) 800 addl %edi,R(_bootinfo+BI_ESYMTAB) 801over_symalloc: 802#endif 803 804 addl $PAGE_MASK,%esi 805 andl $~PAGE_MASK,%esi 806 movl %esi,R(_KERNend) /* save end of kernel */ 807 movl %esi,R(physfree) /* next free page is at end of kernel */ 808 809/* Allocate Kernel Page Tables */ 810 ALLOCPAGES(NKPT) 811 movl %esi,R(_KPTphys) 812 813/* Allocate Page Table Directory */ 814 ALLOCPAGES(1) 815 movl %esi,R(_IdlePTD) 816 817/* Allocate UPAGES */ 818 ALLOCPAGES(UPAGES) 819 movl %esi,R(p0upa) 820 addl $KERNBASE, %esi 821 movl %esi, R(_proc0paddr) 822 823#ifdef SMP 824/* Allocate cpu0's private data page */ 825 ALLOCPAGES(1) 826 movl %esi,R(cpu0pp) 827 addl $KERNBASE, %esi 828 movl %esi, R(_cpu0prvpage) /* relocated to KVM space */ 829 830/* Allocate cpu0's private page table for mapping priv page, apic, etc */ 831 ALLOCPAGES(1) 832 movl %esi,R(cpu0pt) 833 addl $KERNBASE, %esi 834 movl %esi, R(_cpu0prvpt) /* relocated to KVM space */ 835#endif /* SMP */ 836 837/* Map read-only from zero to the end of the kernel text section */ 838 xorl %eax, %eax 839#ifdef BDE_DEBUGGER 840/* If the debugger is present, actually map everything read-write. */ 841 cmpl $0,R(_bdb_exists) 842 jne map_read_write 843#endif 844 xorl %edx,%edx 845 846#if !defined(SMP) 847 testl $CPUID_PGE, R(_cpu_feature) 848 jz 2f 849 orl $PG_G,%edx 850#endif 851 8522: movl $R(_etext),%ecx 853 addl $PAGE_MASK,%ecx 854 shrl $PAGE_SHIFT,%ecx 855 fillkptphys(%edx) 856 857/* Map read-write, data, bss and symbols */ 858 movl $R(_etext),%eax 859 addl $PAGE_MASK, %eax 860 andl $~PAGE_MASK, %eax 861map_read_write: 862 movl $PG_RW,%edx 863#if !defined(SMP) 864 testl $CPUID_PGE, R(_cpu_feature) 865 jz 1f 866 orl $PG_G,%edx 867#endif 868 8691: movl R(_KERNend),%ecx 870 subl %eax,%ecx 871 shrl $PAGE_SHIFT,%ecx 872 fillkptphys(%edx) 873 874/* Map page directory. */ 875 movl R(_IdlePTD), %eax 876 movl $1, %ecx 877 fillkptphys($PG_RW) 878 879/* Map proc0's UPAGES in the physical way ... */ 880 movl R(p0upa), %eax 881 movl $UPAGES, %ecx 882 fillkptphys($PG_RW) 883 884/* Map ISA hole */ 885 movl $ISA_HOLE_START, %eax 886 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 887 fillkptphys($PG_RW) 888 889#ifdef SMP 890/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 891 movl R(cpu0pp), %eax 892 movl $1, %ecx 893 fillkptphys($PG_RW) 894 895/* Map cpu0's private page table into global kmem FWIW */ 896 movl R(cpu0pt), %eax 897 movl $1, %ecx 898 fillkptphys($PG_RW) 899 900/* Map the private page into the private page table into private space */ 901 movl R(cpu0pp), %eax 902 movl $0, %ebx /* pte offset = 0 */ 903 movl $1, %ecx /* one private page coming right up */ 904 fillkpt(R(cpu0pt), $PG_RW) 905 906/* Map the page table page into private space */ 907 movl R(cpu0pt), %eax 908 movl $1, %ebx /* pte offset = 1 */ 909 movl $1, %ecx /* one private pt coming right up */ 910 fillkpt(R(cpu0pt), $PG_RW) 911 912/* ... and put the page table table in the pde. */ 913 movl R(cpu0pt), %eax 914 movl $MPPTDI, %ebx 915 movl $1, %ecx 916 fillkpt(R(_IdlePTD), $PG_RW) 917#endif /* SMP */ 918 919/* install a pde for temporary double map of bottom of VA */ 920 movl R(_KPTphys), %eax 921 xorl %ebx, %ebx 922 movl $1, %ecx 923 fillkpt(R(_IdlePTD), $PG_RW) 924 925/* install pde's for pt's */ 926 movl R(_KPTphys), %eax 927 movl $KPTDI, %ebx 928 movl $NKPT, %ecx 929 fillkpt(R(_IdlePTD), $PG_RW) 930 931/* install a pde recursively mapping page directory as a page table */ 932 movl R(_IdlePTD), %eax 933 movl $PTDPTDI, %ebx 934 movl $1,%ecx 935 fillkpt(R(_IdlePTD), $PG_RW) 936 937 ret 938 939#ifdef BDE_DEBUGGER 940bdb_prepare_paging: 941 cmpl $0,R(_bdb_exists) 942 je bdb_prepare_paging_exit 943 944 subl $6,%esp 945 946 /* 947 * Copy and convert debugger entries from the bootstrap gdt and idt 948 * to the kernel gdt and idt. Everything is still in low memory. 949 * Tracing continues to work after paging is enabled because the 950 * low memory addresses remain valid until everything is relocated. 951 * However, tracing through the setidt() that initializes the trace 952 * trap will crash. 953 */ 954 sgdt (%esp) 955 movl 2(%esp),%esi /* base address of bootstrap gdt */ 956 movl $R(_gdt),%edi 957 movl %edi,2(%esp) /* prepare to load kernel gdt */ 958 movl $8*18/4,%ecx 959 cld 960 rep /* copy gdt */ 961 movsl 962 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 963 movb $0x92,-8+5(%edi) 964 lgdt (%esp) 965 966 sidt (%esp) 967 movl 2(%esp),%esi /* base address of current idt */ 968 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 969 movw 8(%esi),%ax 970 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 971 movl 8+2(%esi),%eax 972 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 973 movl 24+4(%esi),%eax /* same for bpt descriptor */ 974 movw 24(%esi),%ax 975 movl %eax,R(bdb_bpt_ljmp+1) 976 movl 24+2(%esi),%eax 977 movw %ax,R(bdb_bpt_ljmp+5) 978 movl $R(_idt),%edi 979 movl %edi,2(%esp) /* prepare to load kernel idt */ 980 movl $8*4/4,%ecx 981 cld 982 rep /* copy idt */ 983 movsl 984 lidt (%esp) 985 986 addl $6,%esp 987 988bdb_prepare_paging_exit: 989 ret 990 991/* Relocate debugger gdt entries and gdt and idt pointers. */ 992bdb_commit_paging: 993 cmpl $0,_bdb_exists 994 je bdb_commit_paging_exit 995 996 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 997 movl $9,%ecx 998reloc_gdt: 999 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 1000 addl $8,%eax /* now KERNBASE>>24 */ 1001 loop reloc_gdt 1002 1003 subl $6,%esp 1004 sgdt (%esp) 1005 addl $KERNBASE,2(%esp) 1006 lgdt (%esp) 1007 sidt (%esp) 1008 addl $KERNBASE,2(%esp) 1009 lidt (%esp) 1010 addl $6,%esp 1011 1012 int $3 1013 1014bdb_commit_paging_exit: 1015 ret 1016 1017#endif /* BDE_DEBUGGER */ 1018