locore.s revision 61422
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 * $FreeBSD: head/sys/i386/i386/locore.s 61422 2000-06-08 17:53:43Z bde $ 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 "opt_bootp.h" 47#include "opt_nfsroot.h" 48 49#include <sys/syscall.h> 50#include <sys/reboot.h> 51 52#include <machine/asmacros.h> 53#include <machine/cputypes.h> 54#include <machine/psl.h> 55#include <machine/pmap.h> 56#include <machine/specialreg.h> 57 58#include "assym.s" 59 60/* 61 * XXX 62 * 63 * Note: This version greatly munged to avoid various assembler errors 64 * that may be fixed in newer versions of gas. Perhaps newer versions 65 * will have more pleasant appearance. 66 */ 67 68/* 69 * PTmap is recursive pagemap at top of virtual address space. 70 * Within PTmap, the page directory can be found (third indirection). 71 */ 72 .globl _PTmap,_PTD,_PTDpde 73 .set _PTmap,(PTDPTDI << PDRSHIFT) 74 .set _PTD,_PTmap + (PTDPTDI * PAGE_SIZE) 75 .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 76 77/* 78 * APTmap, APTD is the alternate recursive pagemap. 79 * It's used when modifying another process's page tables. 80 */ 81 .globl _APTmap,_APTD,_APTDpde 82 .set _APTmap,APTDPTDI << PDRSHIFT 83 .set _APTD,_APTmap + (APTDPTDI * PAGE_SIZE) 84 .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 85 86/* 87 * Globals 88 */ 89 .data 90 ALIGN_DATA /* just to be sure */ 91 92 .globl HIDENAME(tmpstk) 93 .space 0x2000 /* space for tmpstk - temporary stack */ 94HIDENAME(tmpstk): 95 96 .globl _boothowto,_bootdev 97 98 .globl _cpu,_cpu_vendor,_cpu_id,_bootinfo 99 .globl _cpu_high, _cpu_feature 100 101_cpu: .long 0 /* are we 386, 386sx, or 486 */ 102_cpu_id: .long 0 /* stepping ID */ 103_cpu_high: .long 0 /* highest arg to CPUID */ 104_cpu_feature: .long 0 /* features */ 105_cpu_vendor: .space 20 /* CPU origin code */ 106_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 107 108_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 109physfree: .long 0 /* phys addr of next free page */ 110 111#ifdef SMP 112 .globl _cpu0prvpage 113cpu0pp: .long 0 /* phys addr cpu0 private pg */ 114_cpu0prvpage: .long 0 /* relocated version */ 115 116 .globl _SMPpt 117SMPptpa: .long 0 /* phys addr SMP page table */ 118_SMPpt: .long 0 /* relocated version */ 119#endif /* SMP */ 120 121 .globl _IdlePTD 122_IdlePTD: .long 0 /* phys addr of kernel PTD */ 123 124#ifdef SMP 125 .globl _KPTphys 126#endif 127_KPTphys: .long 0 /* phys addr of kernel page tables */ 128 129 .globl _proc0paddr 130_proc0paddr: .long 0 /* address of proc 0 address space */ 131p0upa: .long 0 /* phys addr of proc0's UPAGES */ 132 133vm86phystk: .long 0 /* PA of vm86/bios stack */ 134 135 .globl _vm86paddr, _vm86pa 136_vm86paddr: .long 0 /* address of vm86 region */ 137_vm86pa: .long 0 /* phys addr of vm86 region */ 138 139#ifdef BDE_DEBUGGER 140 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 141_bdb_exists: .long 0 142#endif 143 144#ifdef PC98 145 .globl _pc98_system_parameter 146_pc98_system_parameter: 147 .space 0x240 148#endif 149 150/********************************************************************** 151 * 152 * Some handy macros 153 * 154 */ 155 156#define R(foo) ((foo)-KERNBASE) 157 158#define ALLOCPAGES(foo) \ 159 movl R(physfree), %esi ; \ 160 movl $((foo)*PAGE_SIZE), %eax ; \ 161 addl %esi, %eax ; \ 162 movl %eax, R(physfree) ; \ 163 movl %esi, %edi ; \ 164 movl $((foo)*PAGE_SIZE),%ecx ; \ 165 xorl %eax,%eax ; \ 166 cld ; \ 167 rep ; \ 168 stosb 169 170/* 171 * fillkpt 172 * eax = page frame address 173 * ebx = index into page table 174 * ecx = how many pages to map 175 * base = base address of page dir/table 176 * prot = protection bits 177 */ 178#define fillkpt(base, prot) \ 179 shll $2,%ebx ; \ 180 addl base,%ebx ; \ 181 orl $PG_V,%eax ; \ 182 orl prot,%eax ; \ 1831: movl %eax,(%ebx) ; \ 184 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 185 addl $4,%ebx ; /* next pte */ \ 186 loop 1b 187 188/* 189 * fillkptphys(prot) 190 * eax = physical address 191 * ecx = how many pages to map 192 * prot = protection bits 193 */ 194#define fillkptphys(prot) \ 195 movl %eax, %ebx ; \ 196 shrl $PAGE_SHIFT, %ebx ; \ 197 fillkpt(R(_KPTphys), prot) 198 199 .text 200/********************************************************************** 201 * 202 * This is where the bootblocks start us, set the ball rolling... 203 * 204 */ 205NON_GPROF_ENTRY(btext) 206 207#ifdef PC98 208 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 209 movl $0xa1400,%esi 210 movl $R(_pc98_system_parameter),%edi 211 movl $0x0240,%ecx 212 cld 213 rep 214 movsb 215#else /* IBM-PC */ 216#ifdef BDE_DEBUGGER 217#ifdef BIOS_STEALS_3K 218 cmpl $0x0375c339,0x95504 219#else 220 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 221#endif 222 jne 1f 223 movb $1,R(_bdb_exists) 2241: 225#endif 226/* Tell the bios to warmboot next time */ 227 movw $0x1234,0x472 228#endif /* PC98 */ 229 230/* Set up a real frame in case the double return in newboot is executed. */ 231 pushl %ebp 232 movl %esp, %ebp 233 234/* Don't trust what the BIOS gives for eflags. */ 235 pushl $PSL_KERNEL 236 popfl 237 238/* 239 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 240 * to set %cs, %ds, %es and %ss. 241 */ 242 mov %ds, %ax 243 mov %ax, %fs 244 mov %ax, %gs 245 246 call recover_bootinfo 247 248/* Get onto a stack that we can trust. */ 249/* 250 * XXX this step is delayed in case recover_bootinfo needs to return via 251 * the old stack, but it need not be, since recover_bootinfo actually 252 * returns via the old frame. 253 */ 254 movl $R(HIDENAME(tmpstk)),%esp 255 256#ifdef PC98 257 /* pc98_machine_type & M_EPSON_PC98 */ 258 testb $0x02,R(_pc98_system_parameter)+220 259 jz 3f 260 /* epson_machine_id <= 0x0b */ 261 cmpb $0x0b,R(_pc98_system_parameter)+224 262 ja 3f 263 264 /* count up memory */ 265 movl $0x100000,%eax /* next, talley remaining memory */ 266 movl $0xFFF-0x100,%ecx 2671: movl 0(%eax),%ebx /* save location to check */ 268 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 269 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 270 jne 2f 271 movl %ebx,0(%eax) /* restore memory */ 272 addl $PAGE_SIZE,%eax 273 loop 1b 2742: subl $0x100000,%eax 275 shrl $17,%eax 276 movb %al,R(_pc98_system_parameter)+1 2773: 278 279 movw R(_pc98_system_parameter+0x86),%ax 280 movw %ax,R(_cpu_id) 281#endif 282 283 call identify_cpu 284 285/* clear bss */ 286/* 287 * XXX this should be done a little earlier. 288 * 289 * XXX we don't check that there is memory for our bss and page tables 290 * before using it. 291 * 292 * XXX the boot program somewhat bogusly clears the bss. We still have 293 * to do it in case we were unzipped by kzipboot. Then the boot program 294 * only clears kzipboot's bss. 295 * 296 * XXX the gdt and idt are still somewhere in the boot program. We 297 * depend on the convention that the boot program is below 1MB and we 298 * are above 1MB to keep the gdt and idt away from the bss and page 299 * tables. The idt is only used if BDE_DEBUGGER is enabled. 300 */ 301 movl $R(_end),%ecx 302 movl $R(_edata),%edi 303 subl %edi,%ecx 304 xorl %eax,%eax 305 cld 306 rep 307 stosb 308 309 call create_pagetables 310 311/* 312 * If the CPU has support for VME, turn it on. 313 */ 314 testl $CPUID_VME, R(_cpu_feature) 315 jz 1f 316 movl %cr4, %eax 317 orl $CR4_VME, %eax 318 movl %eax, %cr4 3191: 320 321#ifdef BDE_DEBUGGER 322/* 323 * Adjust as much as possible for paging before enabling paging so that the 324 * adjustments can be traced. 325 */ 326 call bdb_prepare_paging 327#endif 328 329/* Now enable paging */ 330 movl R(_IdlePTD), %eax 331 movl %eax,%cr3 /* load ptd addr into mmu */ 332 movl %cr0,%eax /* get control word */ 333 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 334 movl %eax,%cr0 /* and let's page NOW! */ 335 336#ifdef BDE_DEBUGGER 337/* 338 * Complete the adjustments for paging so that we can keep tracing through 339 * initi386() after the low (physical) addresses for the gdt and idt become 340 * invalid. 341 */ 342 call bdb_commit_paging 343#endif 344 345 pushl $begin /* jump to high virtualized address */ 346 ret 347 348/* now running relocated at KERNBASE where the system is linked to run */ 349begin: 350 /* set up bootstrap stack */ 351 movl _proc0paddr,%esp /* location of in-kernel pages */ 352 addl $UPAGES*PAGE_SIZE,%esp /* bootstrap stack end location */ 353 xorl %eax,%eax /* mark end of frames */ 354 movl %eax,%ebp 355 movl _proc0paddr,%eax 356 movl _IdlePTD, %esi 357 movl %esi,PCB_CR3(%eax) 358 359 movl physfree, %esi 360 pushl %esi /* value of first for init386(first) */ 361 call _init386 /* wire 386 chip for unix operation */ 362 popl %esi 363 364 .globl __ucodesel,__udatasel 365 366 pushl $0 /* unused */ 367 pushl __udatasel /* ss */ 368 pushl $0 /* esp - filled in by execve() */ 369 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 370 pushl __ucodesel /* cs */ 371 pushl $0 /* eip - filled in by execve() */ 372 subl $(13*4),%esp /* space for rest of registers */ 373 374 pushl %esp /* call main with frame pointer */ 375 call _mi_startup /* autoconfiguration, mountroot etc */ 376 377 hlt /* never returns to here */ 378 379/* 380 * When starting init, call this to configure the process for user 381 * mode. This will be inherited by other processes. 382 */ 383NON_GPROF_ENTRY(prepare_usermode) 384 /* 385 * Now we've run main() and determined what cpu-type we are, we can 386 * enable write protection and alignment checking on i486 cpus and 387 * above. 388 */ 389#if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU) 390 cmpl $CPUCLASS_386,_cpu_class 391 je 1f 392 movl %cr0,%eax /* get control word */ 393 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 394 movl %eax,%cr0 /* and do it */ 3951: 396#endif 397 /* 398 * on return from main(), we are process 1 399 * set up address space and stack so that we can 'return' to user mode 400 */ 401 movl __ucodesel,%eax 402 movl __udatasel,%ecx 403 404#if 0 /* ds/es/fs are in trap frame */ 405 mov %cx,%ds 406 mov %cx,%es 407 mov %cx,%fs 408#endif 409 mov %cx,%gs /* and ds to gs */ 410 ret /* goto user! */ 411 412 413/* 414 * Signal trampoline, copied to top of user stack 415 */ 416NON_GPROF_ENTRY(sigcode) 417 call *SIGF_HANDLER(%esp) /* call signal handler */ 418 lea SIGF_UC(%esp),%eax /* get ucontext_t */ 419 pushl %eax 420 testl $PSL_VM,UC_EFLAGS(%eax) 421 jne 9f 422 movl UC_GS(%eax),%gs /* restore %gs */ 4239: 424 movl $SYS_sigreturn,%eax 425 pushl %eax /* junk to fake return addr. */ 426 int $0x80 /* enter kernel with args */ 4270: jmp 0b 428 429 ALIGN_TEXT 430_osigcode: 431 call *SIGF_HANDLER(%esp) /* call signal handler */ 432 lea SIGF_SC(%esp),%eax /* get sigcontext */ 433 pushl %eax 434 testl $PSL_VM,SC_PS(%eax) 435 jne 9f 436 movl SC_GS(%eax),%gs /* restore %gs */ 4379: 438 movl $0x01d516,SC_TRAPNO(%eax) /* magic: 0ldSiG */ 439 movl $SYS_sigreturn,%eax 440 pushl %eax /* junk to fake return addr. */ 441 int $0x80 /* enter kernel with args */ 4420: jmp 0b 443 444 ALIGN_TEXT 445_esigcode: 446 447 .data 448 .globl _szsigcode, _szosigcode 449_szsigcode: 450 .long _esigcode-_sigcode 451_szosigcode: 452 .long _esigcode-_osigcode 453 .text 454 455/********************************************************************** 456 * 457 * Recover the bootinfo passed to us from the boot program 458 * 459 */ 460recover_bootinfo: 461 /* 462 * This code is called in different ways depending on what loaded 463 * and started the kernel. This is used to detect how we get the 464 * arguments from the other code and what we do with them. 465 * 466 * Old disk boot blocks: 467 * (*btext)(howto, bootdev, cyloffset, esym); 468 * [return address == 0, and can NOT be returned to] 469 * [cyloffset was not supported by the FreeBSD boot code 470 * and always passed in as 0] 471 * [esym is also known as total in the boot code, and 472 * was never properly supported by the FreeBSD boot code] 473 * 474 * Old diskless netboot code: 475 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 476 * [return address != 0, and can NOT be returned to] 477 * If we are being booted by this code it will NOT work, 478 * so we are just going to halt if we find this case. 479 * 480 * New uniform boot code: 481 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 482 * [return address != 0, and can be returned to] 483 * 484 * There may seem to be a lot of wasted arguments in here, but 485 * that is so the newer boot code can still load very old kernels 486 * and old boot code can load new kernels. 487 */ 488 489 /* 490 * The old style disk boot blocks fake a frame on the stack and 491 * did an lret to get here. The frame on the stack has a return 492 * address of 0. 493 */ 494 cmpl $0,4(%ebp) 495 je olddiskboot 496 497 /* 498 * We have some form of return address, so this is either the 499 * old diskless netboot code, or the new uniform code. That can 500 * be detected by looking at the 5th argument, if it is 0 501 * we are being booted by the new uniform boot code. 502 */ 503 cmpl $0,24(%ebp) 504 je newboot 505 506 /* 507 * Seems we have been loaded by the old diskless boot code, we 508 * don't stand a chance of running as the diskless structure 509 * changed considerably between the two, so just halt. 510 */ 511 hlt 512 513 /* 514 * We have been loaded by the new uniform boot code. 515 * Let's check the bootinfo version, and if we do not understand 516 * it we return to the loader with a status of 1 to indicate this error 517 */ 518newboot: 519 movl 28(%ebp),%ebx /* &bootinfo.version */ 520 movl BI_VERSION(%ebx),%eax 521 cmpl $1,%eax /* We only understand version 1 */ 522 je 1f 523 movl $1,%eax /* Return status */ 524 leave 525 /* 526 * XXX this returns to our caller's caller (as is required) since 527 * we didn't set up a frame and our caller did. 528 */ 529 ret 530 5311: 532 /* 533 * If we have a kernelname copy it in 534 */ 535 movl BI_KERNELNAME(%ebx),%esi 536 cmpl $0,%esi 537 je 2f /* No kernelname */ 538 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 539 movl $R(_kernelname),%edi 540 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 541 je 1f 542 movb $'/',(%edi) 543 incl %edi 544 decl %ecx 5451: 546 cld 547 rep 548 movsb 549 5502: 551 /* 552 * Determine the size of the boot loader's copy of the bootinfo 553 * struct. This is impossible to do properly because old versions 554 * of the struct don't contain a size field and there are 2 old 555 * versions with the same version number. 556 */ 557 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 558 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 559 je got_bi_size /* no, sizeless version */ 560 movl BI_SIZE(%ebx),%ecx 561got_bi_size: 562 563 /* 564 * Copy the common part of the bootinfo struct 565 */ 566 movl %ebx,%esi 567 movl $R(_bootinfo),%edi 568 cmpl $BOOTINFO_SIZE,%ecx 569 jbe got_common_bi_size 570 movl $BOOTINFO_SIZE,%ecx 571got_common_bi_size: 572 cld 573 rep 574 movsb 575 576#ifdef NFS_ROOT 577#ifndef BOOTP_NFSV3 578 /* 579 * If we have a nfs_diskless structure copy it in 580 */ 581 movl BI_NFS_DISKLESS(%ebx),%esi 582 cmpl $0,%esi 583 je olddiskboot 584 movl $R(_nfs_diskless),%edi 585 movl $NFSDISKLESS_SIZE,%ecx 586 cld 587 rep 588 movsb 589 movl $R(_nfs_diskless_valid),%edi 590 movl $1,(%edi) 591#endif 592#endif 593 594 /* 595 * The old style disk boot. 596 * (*btext)(howto, bootdev, cyloffset, esym); 597 * Note that the newer boot code just falls into here to pick 598 * up howto and bootdev, cyloffset and esym are no longer used 599 */ 600olddiskboot: 601 movl 8(%ebp),%eax 602 movl %eax,R(_boothowto) 603 movl 12(%ebp),%eax 604 movl %eax,R(_bootdev) 605 606 ret 607 608 609/********************************************************************** 610 * 611 * Identify the CPU and initialize anything special about it 612 * 613 */ 614identify_cpu: 615 616 /* Try to toggle alignment check flag; does not exist on 386. */ 617 pushfl 618 popl %eax 619 movl %eax,%ecx 620 orl $PSL_AC,%eax 621 pushl %eax 622 popfl 623 pushfl 624 popl %eax 625 xorl %ecx,%eax 626 andl $PSL_AC,%eax 627 pushl %ecx 628 popfl 629 630 testl %eax,%eax 631 jnz try486 632 633 /* NexGen CPU does not have aligment check flag. */ 634 pushfl 635 movl $0x5555, %eax 636 xorl %edx, %edx 637 movl $2, %ecx 638 clc 639 divl %ecx 640 jz trynexgen 641 popfl 642 movl $CPU_386,R(_cpu) 643 jmp 3f 644 645trynexgen: 646 popfl 647 movl $CPU_NX586,R(_cpu) 648 movl $0x4778654e,R(_cpu_vendor) # store vendor string 649 movl $0x72446e65,R(_cpu_vendor+4) 650 movl $0x6e657669,R(_cpu_vendor+8) 651 movl $0,R(_cpu_vendor+12) 652 jmp 3f 653 654try486: /* Try to toggle identification flag; does not exist on early 486s. */ 655 pushfl 656 popl %eax 657 movl %eax,%ecx 658 xorl $PSL_ID,%eax 659 pushl %eax 660 popfl 661 pushfl 662 popl %eax 663 xorl %ecx,%eax 664 andl $PSL_ID,%eax 665 pushl %ecx 666 popfl 667 668 testl %eax,%eax 669 jnz trycpuid 670 movl $CPU_486,R(_cpu) 671 672 /* 673 * Check Cyrix CPU 674 * Cyrix CPUs do not change the undefined flags following 675 * execution of the divide instruction which divides 5 by 2. 676 * 677 * Note: CPUID is enabled on M2, so it passes another way. 678 */ 679 pushfl 680 movl $0x5555, %eax 681 xorl %edx, %edx 682 movl $2, %ecx 683 clc 684 divl %ecx 685 jnc trycyrix 686 popfl 687 jmp 3f /* You may use Intel CPU. */ 688 689trycyrix: 690 popfl 691 /* 692 * IBM Bluelighting CPU also doesn't change the undefined flags. 693 * Because IBM doesn't disclose the information for Bluelighting 694 * CPU, we couldn't distinguish it from Cyrix's (including IBM 695 * brand of Cyrix CPUs). 696 */ 697 movl $0x69727943,R(_cpu_vendor) # store vendor string 698 movl $0x736e4978,R(_cpu_vendor+4) 699 movl $0x64616574,R(_cpu_vendor+8) 700 jmp 3f 701 702trycpuid: /* Use the `cpuid' instruction. */ 703 xorl %eax,%eax 704 .byte 0x0f,0xa2 # cpuid 0 705 movl %eax,R(_cpu_high) # highest capability 706 movl %ebx,R(_cpu_vendor) # store vendor string 707 movl %edx,R(_cpu_vendor+4) 708 movl %ecx,R(_cpu_vendor+8) 709 movb $0,R(_cpu_vendor+12) 710 711 movl $1,%eax 712 .byte 0x0f,0xa2 # cpuid 1 713 movl %eax,R(_cpu_id) # store cpu_id 714 movl %edx,R(_cpu_feature) # store cpu_feature 715 rorl $8,%eax # extract family type 716 andl $15,%eax 717 cmpl $5,%eax 718 jae 1f 719 720 /* less than Pentium; must be 486 */ 721 movl $CPU_486,R(_cpu) 722 jmp 3f 7231: 724 /* a Pentium? */ 725 cmpl $5,%eax 726 jne 2f 727 movl $CPU_586,R(_cpu) 728 jmp 3f 7292: 730 /* Greater than Pentium...call it a Pentium Pro */ 731 movl $CPU_686,R(_cpu) 7323: 733 ret 734 735 736/********************************************************************** 737 * 738 * Create the first page directory and its page tables. 739 * 740 */ 741 742create_pagetables: 743 744 testl $CPUID_PGE, R(_cpu_feature) 745 jz 1f 746 movl %cr4, %eax 747 orl $CR4_PGE, %eax 748 movl %eax, %cr4 7491: 750 751/* Find end of kernel image (rounded up to a page boundary). */ 752 movl $R(_end),%esi 753 754/* Include symbols, if any. */ 755 movl R(_bootinfo+BI_ESYMTAB),%edi 756 testl %edi,%edi 757 je over_symalloc 758 movl %edi,%esi 759 movl $KERNBASE,%edi 760 addl %edi,R(_bootinfo+BI_SYMTAB) 761 addl %edi,R(_bootinfo+BI_ESYMTAB) 762over_symalloc: 763 764/* If we are told where the end of the kernel space is, believe it. */ 765 movl R(_bootinfo+BI_KERNEND),%edi 766 testl %edi,%edi 767 je no_kernend 768 movl %edi,%esi 769no_kernend: 770 771 addl $PAGE_MASK,%esi 772 andl $~PAGE_MASK,%esi 773 movl %esi,R(_KERNend) /* save end of kernel */ 774 movl %esi,R(physfree) /* next free page is at end of kernel */ 775 776/* Allocate Kernel Page Tables */ 777 ALLOCPAGES(NKPT) 778 movl %esi,R(_KPTphys) 779 780/* Allocate Page Table Directory */ 781 ALLOCPAGES(1) 782 movl %esi,R(_IdlePTD) 783 784/* Allocate UPAGES */ 785 ALLOCPAGES(UPAGES) 786 movl %esi,R(p0upa) 787 addl $KERNBASE, %esi 788 movl %esi, R(_proc0paddr) 789 790 ALLOCPAGES(1) /* vm86/bios stack */ 791 movl %esi,R(vm86phystk) 792 793 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 794 movl %esi,R(_vm86pa) 795 addl $KERNBASE, %esi 796 movl %esi, R(_vm86paddr) 797 798#ifdef SMP 799/* Allocate cpu0's private data page */ 800 ALLOCPAGES(1) 801 movl %esi,R(cpu0pp) 802 addl $KERNBASE, %esi 803 movl %esi, R(_cpu0prvpage) /* relocated to KVM space */ 804 805/* Allocate SMP page table page */ 806 ALLOCPAGES(1) 807 movl %esi,R(SMPptpa) 808 addl $KERNBASE, %esi 809 movl %esi, R(_SMPpt) /* relocated to KVM space */ 810#endif /* SMP */ 811 812/* Map read-only from zero to the end of the kernel text section */ 813 xorl %eax, %eax 814#ifdef BDE_DEBUGGER 815/* If the debugger is present, actually map everything read-write. */ 816 cmpl $0,R(_bdb_exists) 817 jne map_read_write 818#endif 819 xorl %edx,%edx 820 821#if !defined(SMP) 822 testl $CPUID_PGE, R(_cpu_feature) 823 jz 2f 824 orl $PG_G,%edx 825#endif 826 8272: movl $R(_etext),%ecx 828 addl $PAGE_MASK,%ecx 829 shrl $PAGE_SHIFT,%ecx 830 fillkptphys(%edx) 831 832/* Map read-write, data, bss and symbols */ 833 movl $R(_etext),%eax 834 addl $PAGE_MASK, %eax 835 andl $~PAGE_MASK, %eax 836map_read_write: 837 movl $PG_RW,%edx 838#if !defined(SMP) 839 testl $CPUID_PGE, R(_cpu_feature) 840 jz 1f 841 orl $PG_G,%edx 842#endif 843 8441: movl R(_KERNend),%ecx 845 subl %eax,%ecx 846 shrl $PAGE_SHIFT,%ecx 847 fillkptphys(%edx) 848 849/* Map page directory. */ 850 movl R(_IdlePTD), %eax 851 movl $1, %ecx 852 fillkptphys($PG_RW) 853 854/* Map proc0's UPAGES in the physical way ... */ 855 movl R(p0upa), %eax 856 movl $UPAGES, %ecx 857 fillkptphys($PG_RW) 858 859/* Map ISA hole */ 860 movl $ISA_HOLE_START, %eax 861 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 862 fillkptphys($PG_RW) 863 864/* Map space for the vm86 region */ 865 movl R(vm86phystk), %eax 866 movl $4, %ecx 867 fillkptphys($PG_RW) 868 869/* Map page 0 into the vm86 page table */ 870 movl $0, %eax 871 movl $0, %ebx 872 movl $1, %ecx 873 fillkpt(R(_vm86pa), $PG_RW|PG_U) 874 875/* ...likewise for the ISA hole */ 876 movl $ISA_HOLE_START, %eax 877 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 878 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 879 fillkpt(R(_vm86pa), $PG_RW|PG_U) 880 881#ifdef SMP 882/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 883 movl R(cpu0pp), %eax 884 movl $1, %ecx 885 fillkptphys($PG_RW) 886 887/* Map SMP page table page into global kmem FWIW */ 888 movl R(SMPptpa), %eax 889 movl $1, %ecx 890 fillkptphys($PG_RW) 891 892/* Map the private page into the SMP page table */ 893 movl R(cpu0pp), %eax 894 movl $0, %ebx /* pte offset = 0 */ 895 movl $1, %ecx /* one private page coming right up */ 896 fillkpt(R(SMPptpa), $PG_RW) 897 898/* ... and put the page table table in the pde. */ 899 movl R(SMPptpa), %eax 900 movl $MPPTDI, %ebx 901 movl $1, %ecx 902 fillkpt(R(_IdlePTD), $PG_RW) 903 904/* Fakeup VA for the local apic to allow early traps. */ 905 ALLOCPAGES(1) 906 movl %esi, %eax 907 movl $(NPTEPG-1), %ebx /* pte offset = NTEPG-1 */ 908 movl $1, %ecx /* one private pt coming right up */ 909 fillkpt(R(SMPptpa), $PG_RW) 910 911/* Initialize mp lock to allow early traps */ 912 movl $1, R(_mp_lock) 913#endif /* SMP */ 914 915/* install a pde for temporary double map of bottom of VA */ 916 movl R(_KPTphys), %eax 917 xorl %ebx, %ebx 918 movl $1, %ecx 919 fillkpt(R(_IdlePTD), $PG_RW) 920 921/* install pde's for pt's */ 922 movl R(_KPTphys), %eax 923 movl $KPTDI, %ebx 924 movl $NKPT, %ecx 925 fillkpt(R(_IdlePTD), $PG_RW) 926 927/* install a pde recursively mapping page directory as a page table */ 928 movl R(_IdlePTD), %eax 929 movl $PTDPTDI, %ebx 930 movl $1,%ecx 931 fillkpt(R(_IdlePTD), $PG_RW) 932 933 ret 934 935#ifdef BDE_DEBUGGER 936bdb_prepare_paging: 937 cmpl $0,R(_bdb_exists) 938 je bdb_prepare_paging_exit 939 940 subl $6,%esp 941 942 /* 943 * Copy and convert debugger entries from the bootstrap gdt and idt 944 * to the kernel gdt and idt. Everything is still in low memory. 945 * Tracing continues to work after paging is enabled because the 946 * low memory addresses remain valid until everything is relocated. 947 * However, tracing through the setidt() that initializes the trace 948 * trap will crash. 949 */ 950 sgdt (%esp) 951 movl 2(%esp),%esi /* base address of bootstrap gdt */ 952 movl $R(_gdt),%edi 953 movl %edi,2(%esp) /* prepare to load kernel gdt */ 954 movl $8*18/4,%ecx 955 cld 956 rep /* copy gdt */ 957 movsl 958 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 959 movb $0x92,-8+5(%edi) 960 lgdt (%esp) 961 962 sidt (%esp) 963 movl 2(%esp),%esi /* base address of current idt */ 964 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 965 movw 8(%esi),%ax 966 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 967 movl 8+2(%esi),%eax 968 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 969 movl 24+4(%esi),%eax /* same for bpt descriptor */ 970 movw 24(%esi),%ax 971 movl %eax,R(bdb_bpt_ljmp+1) 972 movl 24+2(%esi),%eax 973 movw %ax,R(bdb_bpt_ljmp+5) 974 movl R(_idt),%edi 975 movl %edi,2(%esp) /* prepare to load kernel idt */ 976 movl $8*4/4,%ecx 977 cld 978 rep /* copy idt */ 979 movsl 980 lidt (%esp) 981 982 addl $6,%esp 983 984bdb_prepare_paging_exit: 985 ret 986 987/* Relocate debugger gdt entries and gdt and idt pointers. */ 988bdb_commit_paging: 989 cmpl $0,_bdb_exists 990 je bdb_commit_paging_exit 991 992 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 993 movl $9,%ecx 994reloc_gdt: 995 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 996 addl $8,%eax /* now KERNBASE>>24 */ 997 loop reloc_gdt 998 999 subl $6,%esp 1000 sgdt (%esp) 1001 addl $KERNBASE,2(%esp) 1002 lgdt (%esp) 1003 sidt (%esp) 1004 addl $KERNBASE,2(%esp) 1005 lidt (%esp) 1006 addl $6,%esp 1007 1008 int $3 1009 1010bdb_commit_paging_exit: 1011 ret 1012 1013#endif /* BDE_DEBUGGER */ 1014