locore.s revision 51065
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 51065 1999-09-07 20:02:24Z luoqi $ 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_ddb.h" 48#include "opt_nfsroot.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/* 89 * Globals 90 */ 91 .data 92 ALIGN_DATA /* just to be sure */ 93 94 .globl HIDENAME(tmpstk) 95 .space 0x2000 /* space for tmpstk - temporary stack */ 96HIDENAME(tmpstk): 97 98 .globl _boothowto,_bootdev 99 100 .globl _cpu,_cpu_vendor,_cpu_id,_bootinfo 101 .globl _cpu_high, _cpu_feature 102 103_cpu: .long 0 /* are we 386, 386sx, or 486 */ 104_cpu_id: .long 0 /* stepping ID */ 105_cpu_high: .long 0 /* highest arg to CPUID */ 106_cpu_feature: .long 0 /* features */ 107_cpu_vendor: .space 20 /* CPU origin code */ 108_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 109 110_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 111physfree: .long 0 /* phys addr of next free page */ 112 113#ifdef SMP 114 .globl _cpu0prvpage 115cpu0pp: .long 0 /* phys addr cpu0 private pg */ 116_cpu0prvpage: .long 0 /* relocated version */ 117 118 .globl _SMPpt 119SMPptpa: .long 0 /* phys addr SMP page table */ 120_SMPpt: .long 0 /* relocated version */ 121#endif /* SMP */ 122 123 .globl _IdlePTD 124_IdlePTD: .long 0 /* phys addr of kernel PTD */ 125 126#ifdef SMP 127 .globl _KPTphys 128#endif 129_KPTphys: .long 0 /* phys addr of kernel page tables */ 130 131 .globl _proc0paddr 132_proc0paddr: .long 0 /* address of proc 0 address space */ 133p0upa: .long 0 /* phys addr of proc0's UPAGES */ 134 135vm86phystk: .long 0 /* PA of vm86/bios stack */ 136 137 .globl _vm86paddr, _vm86pa 138_vm86paddr: .long 0 /* address of vm86 region */ 139_vm86pa: .long 0 /* phys addr of vm86 region */ 140 141#ifdef BDE_DEBUGGER 142 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 143_bdb_exists: .long 0 144#endif 145 146#ifdef PC98 147 .globl _pc98_system_parameter 148_pc98_system_parameter: 149 .space 0x240 150#endif 151 152/********************************************************************** 153 * 154 * Some handy macros 155 * 156 */ 157 158#define R(foo) ((foo)-KERNBASE) 159 160#define ALLOCPAGES(foo) \ 161 movl R(physfree), %esi ; \ 162 movl $((foo)*PAGE_SIZE), %eax ; \ 163 addl %esi, %eax ; \ 164 movl %eax, R(physfree) ; \ 165 movl %esi, %edi ; \ 166 movl $((foo)*PAGE_SIZE),%ecx ; \ 167 xorl %eax,%eax ; \ 168 cld ; \ 169 rep ; \ 170 stosb 171 172/* 173 * fillkpt 174 * eax = page frame address 175 * ebx = index into page table 176 * ecx = how many pages to map 177 * base = base address of page dir/table 178 * prot = protection bits 179 */ 180#define fillkpt(base, prot) \ 181 shll $2,%ebx ; \ 182 addl base,%ebx ; \ 183 orl $PG_V,%eax ; \ 184 orl prot,%eax ; \ 1851: movl %eax,(%ebx) ; \ 186 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 187 addl $4,%ebx ; /* next pte */ \ 188 loop 1b 189 190/* 191 * fillkptphys(prot) 192 * eax = physical address 193 * ecx = how many pages to map 194 * prot = protection bits 195 */ 196#define fillkptphys(prot) \ 197 movl %eax, %ebx ; \ 198 shrl $PAGE_SHIFT, %ebx ; \ 199 fillkpt(R(_KPTphys), prot) 200 201 .text 202/********************************************************************** 203 * 204 * This is where the bootblocks start us, set the ball rolling... 205 * 206 */ 207NON_GPROF_ENTRY(btext) 208 209#ifdef PC98 210 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 211 movl $0xa1400,%esi 212 movl $R(_pc98_system_parameter),%edi 213 movl $0x0240,%ecx 214 cld 215 rep 216 movsb 217#else /* IBM-PC */ 218#ifdef BDE_DEBUGGER 219#ifdef BIOS_STEALS_3K 220 cmpl $0x0375c339,0x95504 221#else 222 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 223#endif 224 jne 1f 225 movb $1,R(_bdb_exists) 2261: 227#endif 228#endif /* PC98 */ 229 230/* Tell the bios to warmboot next time */ 231 movw $0x1234,0x472 232 233/* Set up a real frame in case the double return in newboot is executed. */ 234 pushl %ebp 235 movl %esp, %ebp 236 237/* Don't trust what the BIOS gives for eflags. */ 238 pushl $PSL_KERNEL 239 popfl 240 241/* 242 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 243 * to set %cs, %ds, %es and %ss. 244 */ 245 mov %ds, %ax 246 mov %ax, %fs 247 mov %ax, %gs 248 249 call recover_bootinfo 250 251/* Get onto a stack that we can trust. */ 252/* 253 * XXX this step is delayed in case recover_bootinfo needs to return via 254 * the old stack, but it need not be, since recover_bootinfo actually 255 * returns via the old frame. 256 */ 257 movl $R(HIDENAME(tmpstk)),%esp 258 259#ifdef PC98 260 /* pc98_machine_type & M_EPSON_PC98 */ 261 testb $0x02,R(_pc98_system_parameter)+220 262 jz 3f 263 /* epson_machine_id <= 0x0b */ 264 cmpb $0x0b,R(_pc98_system_parameter)+224 265 ja 3f 266 267 /* count up memory */ 268 movl $0x100000,%eax /* next, talley remaining memory */ 269 movl $0xFFF-0x100,%ecx 2701: movl 0(%eax),%ebx /* save location to check */ 271 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 272 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 273 jne 2f 274 movl %ebx,0(%eax) /* restore memory */ 275 addl $PAGE_SIZE,%eax 276 loop 1b 2772: subl $0x100000,%eax 278 shrl $17,%eax 279 movb %al,R(_pc98_system_parameter)+1 2803: 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 movl %cx,%ds 406 movl %cx,%es 407 movl %cx,%fs 408#endif 409 movl %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) 418 lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 419 /* copy at 8(%esp)) */ 420 pushl %eax 421 pushl %eax /* junk to fake return address */ 422 testl $PSL_VM,SC_PS(%eax) 423 jne 1f 424 movl SC_GS(%eax),%gs /* restore %gs */ 4251: 426 movl $SYS_sigreturn,%eax /* sigreturn() */ 427 int $0x80 /* enter kernel with args on stack */ 4282: jmp 2b 429 ALIGN_TEXT 430_esigcode: 431 432 .data 433 .globl _szsigcode 434_szsigcode: 435 .long _esigcode-_sigcode 436 .text 437 438/********************************************************************** 439 * 440 * Recover the bootinfo passed to us from the boot program 441 * 442 */ 443recover_bootinfo: 444 /* 445 * This code is called in different ways depending on what loaded 446 * and started the kernel. This is used to detect how we get the 447 * arguments from the other code and what we do with them. 448 * 449 * Old disk boot blocks: 450 * (*btext)(howto, bootdev, cyloffset, esym); 451 * [return address == 0, and can NOT be returned to] 452 * [cyloffset was not supported by the FreeBSD boot code 453 * and always passed in as 0] 454 * [esym is also known as total in the boot code, and 455 * was never properly supported by the FreeBSD boot code] 456 * 457 * Old diskless netboot code: 458 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 459 * [return address != 0, and can NOT be returned to] 460 * If we are being booted by this code it will NOT work, 461 * so we are just going to halt if we find this case. 462 * 463 * New uniform boot code: 464 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 465 * [return address != 0, and can be returned to] 466 * 467 * There may seem to be a lot of wasted arguments in here, but 468 * that is so the newer boot code can still load very old kernels 469 * and old boot code can load new kernels. 470 */ 471 472 /* 473 * The old style disk boot blocks fake a frame on the stack and 474 * did an lret to get here. The frame on the stack has a return 475 * address of 0. 476 */ 477 cmpl $0,4(%ebp) 478 je olddiskboot 479 480 /* 481 * We have some form of return address, so this is either the 482 * old diskless netboot code, or the new uniform code. That can 483 * be detected by looking at the 5th argument, if it is 0 484 * we are being booted by the new uniform boot code. 485 */ 486 cmpl $0,24(%ebp) 487 je newboot 488 489 /* 490 * Seems we have been loaded by the old diskless boot code, we 491 * don't stand a chance of running as the diskless structure 492 * changed considerably between the two, so just halt. 493 */ 494 hlt 495 496 /* 497 * We have been loaded by the new uniform boot code. 498 * Let's check the bootinfo version, and if we do not understand 499 * it we return to the loader with a status of 1 to indicate this error 500 */ 501newboot: 502 movl 28(%ebp),%ebx /* &bootinfo.version */ 503 movl BI_VERSION(%ebx),%eax 504 cmpl $1,%eax /* We only understand version 1 */ 505 je 1f 506 movl $1,%eax /* Return status */ 507 leave 508 /* 509 * XXX this returns to our caller's caller (as is required) since 510 * we didn't set up a frame and our caller did. 511 */ 512 ret 513 5141: 515 /* 516 * If we have a kernelname copy it in 517 */ 518 movl BI_KERNELNAME(%ebx),%esi 519 cmpl $0,%esi 520 je 2f /* No kernelname */ 521 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 522 movl $R(_kernelname),%edi 523 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 524 je 1f 525 movb $'/',(%edi) 526 incl %edi 527 decl %ecx 5281: 529 cld 530 rep 531 movsb 532 5332: 534 /* 535 * Determine the size of the boot loader's copy of the bootinfo 536 * struct. This is impossible to do properly because old versions 537 * of the struct don't contain a size field and there are 2 old 538 * versions with the same version number. 539 */ 540 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 541 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 542 je got_bi_size /* no, sizeless version */ 543 movl BI_SIZE(%ebx),%ecx 544got_bi_size: 545 546 /* 547 * Copy the common part of the bootinfo struct 548 */ 549 movl %ebx,%esi 550 movl $R(_bootinfo),%edi 551 cmpl $BOOTINFO_SIZE,%ecx 552 jbe got_common_bi_size 553 movl $BOOTINFO_SIZE,%ecx 554got_common_bi_size: 555 cld 556 rep 557 movsb 558 559#ifdef NFS_ROOT 560#ifndef BOOTP_NFSV3 561 /* 562 * If we have a nfs_diskless structure copy it in 563 */ 564 movl BI_NFS_DISKLESS(%ebx),%esi 565 cmpl $0,%esi 566 je olddiskboot 567 movl $R(_nfs_diskless),%edi 568 movl $NFSDISKLESS_SIZE,%ecx 569 cld 570 rep 571 movsb 572 movl $R(_nfs_diskless_valid),%edi 573 movl $1,(%edi) 574#endif 575#endif 576 577 /* 578 * The old style disk boot. 579 * (*btext)(howto, bootdev, cyloffset, esym); 580 * Note that the newer boot code just falls into here to pick 581 * up howto and bootdev, cyloffset and esym are no longer used 582 */ 583olddiskboot: 584 movl 8(%ebp),%eax 585 movl %eax,R(_boothowto) 586 movl 12(%ebp),%eax 587 movl %eax,R(_bootdev) 588 589 ret 590 591 592/********************************************************************** 593 * 594 * Identify the CPU and initialize anything special about it 595 * 596 */ 597identify_cpu: 598 599 /* Try to toggle alignment check flag; does not exist on 386. */ 600 pushfl 601 popl %eax 602 movl %eax,%ecx 603 orl $PSL_AC,%eax 604 pushl %eax 605 popfl 606 pushfl 607 popl %eax 608 xorl %ecx,%eax 609 andl $PSL_AC,%eax 610 pushl %ecx 611 popfl 612 613 testl %eax,%eax 614 jnz try486 615 616 /* NexGen CPU does not have aligment check flag. */ 617 pushfl 618 movl $0x5555, %eax 619 xorl %edx, %edx 620 movl $2, %ecx 621 clc 622 divl %ecx 623 jz trynexgen 624 popfl 625 movl $CPU_386,R(_cpu) 626 jmp 3f 627 628trynexgen: 629 popfl 630 movl $CPU_NX586,R(_cpu) 631 movl $0x4778654e,R(_cpu_vendor) # store vendor string 632 movl $0x72446e65,R(_cpu_vendor+4) 633 movl $0x6e657669,R(_cpu_vendor+8) 634 movl $0,R(_cpu_vendor+12) 635 jmp 3f 636 637try486: /* Try to toggle identification flag; does not exist on early 486s. */ 638 pushfl 639 popl %eax 640 movl %eax,%ecx 641 xorl $PSL_ID,%eax 642 pushl %eax 643 popfl 644 pushfl 645 popl %eax 646 xorl %ecx,%eax 647 andl $PSL_ID,%eax 648 pushl %ecx 649 popfl 650 651 testl %eax,%eax 652 jnz trycpuid 653 movl $CPU_486,R(_cpu) 654 655 /* 656 * Check Cyrix CPU 657 * Cyrix CPUs do not change the undefined flags following 658 * execution of the divide instruction which divides 5 by 2. 659 * 660 * Note: CPUID is enabled on M2, so it passes another way. 661 */ 662 pushfl 663 movl $0x5555, %eax 664 xorl %edx, %edx 665 movl $2, %ecx 666 clc 667 divl %ecx 668 jnc trycyrix 669 popfl 670 jmp 3f /* You may use Intel CPU. */ 671 672trycyrix: 673 popfl 674 /* 675 * IBM Bluelighting CPU also doesn't change the undefined flags. 676 * Because IBM doesn't disclose the information for Bluelighting 677 * CPU, we couldn't distinguish it from Cyrix's (including IBM 678 * brand of Cyrix CPUs). 679 */ 680 movl $0x69727943,R(_cpu_vendor) # store vendor string 681 movl $0x736e4978,R(_cpu_vendor+4) 682 movl $0x64616574,R(_cpu_vendor+8) 683 jmp 3f 684 685trycpuid: /* Use the `cpuid' instruction. */ 686 xorl %eax,%eax 687 .byte 0x0f,0xa2 # cpuid 0 688 movl %eax,R(_cpu_high) # highest capability 689 movl %ebx,R(_cpu_vendor) # store vendor string 690 movl %edx,R(_cpu_vendor+4) 691 movl %ecx,R(_cpu_vendor+8) 692 movb $0,R(_cpu_vendor+12) 693 694 movl $1,%eax 695 .byte 0x0f,0xa2 # cpuid 1 696 movl %eax,R(_cpu_id) # store cpu_id 697 movl %edx,R(_cpu_feature) # store cpu_feature 698 rorl $8,%eax # extract family type 699 andl $15,%eax 700 cmpl $5,%eax 701 jae 1f 702 703 /* less than Pentium; must be 486 */ 704 movl $CPU_486,R(_cpu) 705 jmp 3f 7061: 707 /* a Pentium? */ 708 cmpl $5,%eax 709 jne 2f 710 movl $CPU_586,R(_cpu) 711 jmp 3f 7122: 713 /* Greater than Pentium...call it a Pentium Pro */ 714 movl $CPU_686,R(_cpu) 7153: 716 ret 717 718 719/********************************************************************** 720 * 721 * Create the first page directory and its page tables. 722 * 723 */ 724 725create_pagetables: 726 727 testl $CPUID_PGE, R(_cpu_feature) 728 jz 1f 729 movl %cr4, %eax 730 orl $CR4_PGE, %eax 731 movl %eax, %cr4 7321: 733 734/* Find end of kernel image (rounded up to a page boundary). */ 735 movl $R(_end),%esi 736 737/* include symbols if loaded and useful */ 738#ifdef DDB 739 movl R(_bootinfo+BI_ESYMTAB),%edi 740 testl %edi,%edi 741 je over_symalloc 742 movl %edi,%esi 743 movl $KERNBASE,%edi 744 addl %edi,R(_bootinfo+BI_SYMTAB) 745 addl %edi,R(_bootinfo+BI_ESYMTAB) 746over_symalloc: 747#endif 748 749/* If we are told where the end of the kernel space is, believe it. */ 750 movl R(_bootinfo+BI_KERNEND),%edi 751 testl %edi,%edi 752 je no_kernend 753 movl %edi,%esi 754no_kernend: 755 756 addl $PAGE_MASK,%esi 757 andl $~PAGE_MASK,%esi 758 movl %esi,R(_KERNend) /* save end of kernel */ 759 movl %esi,R(physfree) /* next free page is at end of kernel */ 760 761/* Allocate Kernel Page Tables */ 762 ALLOCPAGES(NKPT) 763 movl %esi,R(_KPTphys) 764 765/* Allocate Page Table Directory */ 766 ALLOCPAGES(1) 767 movl %esi,R(_IdlePTD) 768 769/* Allocate UPAGES */ 770 ALLOCPAGES(UPAGES) 771 movl %esi,R(p0upa) 772 addl $KERNBASE, %esi 773 movl %esi, R(_proc0paddr) 774 775 ALLOCPAGES(1) /* vm86/bios stack */ 776 movl %esi,R(vm86phystk) 777 778 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 779 movl %esi,R(_vm86pa) 780 addl $KERNBASE, %esi 781 movl %esi, R(_vm86paddr) 782 783#ifdef SMP 784/* Allocate cpu0's private data page */ 785 ALLOCPAGES(1) 786 movl %esi,R(cpu0pp) 787 addl $KERNBASE, %esi 788 movl %esi, R(_cpu0prvpage) /* relocated to KVM space */ 789 790/* Allocate SMP page table page */ 791 ALLOCPAGES(1) 792 movl %esi,R(SMPptpa) 793 addl $KERNBASE, %esi 794 movl %esi, R(_SMPpt) /* relocated to KVM space */ 795#endif /* SMP */ 796 797/* Map read-only from zero to the end of the kernel text section */ 798 xorl %eax, %eax 799#ifdef BDE_DEBUGGER 800/* If the debugger is present, actually map everything read-write. */ 801 cmpl $0,R(_bdb_exists) 802 jne map_read_write 803#endif 804 xorl %edx,%edx 805 806#if !defined(SMP) 807 testl $CPUID_PGE, R(_cpu_feature) 808 jz 2f 809 orl $PG_G,%edx 810#endif 811 8122: movl $R(_etext),%ecx 813 addl $PAGE_MASK,%ecx 814 shrl $PAGE_SHIFT,%ecx 815 fillkptphys(%edx) 816 817/* Map read-write, data, bss and symbols */ 818 movl $R(_etext),%eax 819 addl $PAGE_MASK, %eax 820 andl $~PAGE_MASK, %eax 821map_read_write: 822 movl $PG_RW,%edx 823#if !defined(SMP) 824 testl $CPUID_PGE, R(_cpu_feature) 825 jz 1f 826 orl $PG_G,%edx 827#endif 828 8291: movl R(_KERNend),%ecx 830 subl %eax,%ecx 831 shrl $PAGE_SHIFT,%ecx 832 fillkptphys(%edx) 833 834/* Map page directory. */ 835 movl R(_IdlePTD), %eax 836 movl $1, %ecx 837 fillkptphys($PG_RW) 838 839/* Map proc0's UPAGES in the physical way ... */ 840 movl R(p0upa), %eax 841 movl $UPAGES, %ecx 842 fillkptphys($PG_RW) 843 844/* Map ISA hole */ 845 movl $ISA_HOLE_START, %eax 846 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 847 fillkptphys($PG_RW) 848 849/* Map space for the vm86 region */ 850 movl R(vm86phystk), %eax 851 movl $4, %ecx 852 fillkptphys($PG_RW) 853 854/* Map page 0 into the vm86 page table */ 855 movl $0, %eax 856 movl $0, %ebx 857 movl $1, %ecx 858 fillkpt(R(_vm86pa), $PG_RW|PG_U) 859 860/* ...likewise for the ISA hole */ 861 movl $ISA_HOLE_START, %eax 862 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 863 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 864 fillkpt(R(_vm86pa), $PG_RW|PG_U) 865 866#ifdef SMP 867/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 868 movl R(cpu0pp), %eax 869 movl $1, %ecx 870 fillkptphys($PG_RW) 871 872/* Map SMP page table page into global kmem FWIW */ 873 movl R(SMPptpa), %eax 874 movl $1, %ecx 875 fillkptphys($PG_RW) 876 877/* Map the private page into the SMP page table */ 878 movl R(cpu0pp), %eax 879 movl $0, %ebx /* pte offset = 0 */ 880 movl $1, %ecx /* one private page coming right up */ 881 fillkpt(R(SMPptpa), $PG_RW) 882 883/* ... and put the page table table in the pde. */ 884 movl R(SMPptpa), %eax 885 movl $MPPTDI, %ebx 886 movl $1, %ecx 887 fillkpt(R(_IdlePTD), $PG_RW) 888 889/* Fakeup VA for the local apic to allow early traps. */ 890 ALLOCPAGES(1) 891 movl %esi, %eax 892 movl $(NPTEPG-1), %ebx /* pte offset = NTEPG-1 */ 893 movl $1, %ecx /* one private pt coming right up */ 894 fillkpt(R(SMPptpa), $PG_RW) 895 896/* Initialize mp lock to allow early traps */ 897 movl $1, R(_mp_lock) 898#endif /* SMP */ 899 900/* install a pde for temporary double map of bottom of VA */ 901 movl R(_KPTphys), %eax 902 xorl %ebx, %ebx 903 movl $1, %ecx 904 fillkpt(R(_IdlePTD), $PG_RW) 905 906/* install pde's for pt's */ 907 movl R(_KPTphys), %eax 908 movl $KPTDI, %ebx 909 movl $NKPT, %ecx 910 fillkpt(R(_IdlePTD), $PG_RW) 911 912/* install a pde recursively mapping page directory as a page table */ 913 movl R(_IdlePTD), %eax 914 movl $PTDPTDI, %ebx 915 movl $1,%ecx 916 fillkpt(R(_IdlePTD), $PG_RW) 917 918 ret 919 920#ifdef BDE_DEBUGGER 921bdb_prepare_paging: 922 cmpl $0,R(_bdb_exists) 923 je bdb_prepare_paging_exit 924 925 subl $6,%esp 926 927 /* 928 * Copy and convert debugger entries from the bootstrap gdt and idt 929 * to the kernel gdt and idt. Everything is still in low memory. 930 * Tracing continues to work after paging is enabled because the 931 * low memory addresses remain valid until everything is relocated. 932 * However, tracing through the setidt() that initializes the trace 933 * trap will crash. 934 */ 935 sgdt (%esp) 936 movl 2(%esp),%esi /* base address of bootstrap gdt */ 937 movl $R(_gdt),%edi 938 movl %edi,2(%esp) /* prepare to load kernel gdt */ 939 movl $8*18/4,%ecx 940 cld 941 rep /* copy gdt */ 942 movsl 943 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 944 movb $0x92,-8+5(%edi) 945 lgdt (%esp) 946 947 sidt (%esp) 948 movl 2(%esp),%esi /* base address of current idt */ 949 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 950 movw 8(%esi),%ax 951 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 952 movl 8+2(%esi),%eax 953 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 954 movl 24+4(%esi),%eax /* same for bpt descriptor */ 955 movw 24(%esi),%ax 956 movl %eax,R(bdb_bpt_ljmp+1) 957 movl 24+2(%esi),%eax 958 movw %ax,R(bdb_bpt_ljmp+5) 959 movl R(_idt),%edi 960 movl %edi,2(%esp) /* prepare to load kernel idt */ 961 movl $8*4/4,%ecx 962 cld 963 rep /* copy idt */ 964 movsl 965 lidt (%esp) 966 967 addl $6,%esp 968 969bdb_prepare_paging_exit: 970 ret 971 972/* Relocate debugger gdt entries and gdt and idt pointers. */ 973bdb_commit_paging: 974 cmpl $0,_bdb_exists 975 je bdb_commit_paging_exit 976 977 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 978 movl $9,%ecx 979reloc_gdt: 980 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 981 addl $8,%eax /* now KERNBASE>>24 */ 982 loop reloc_gdt 983 984 subl $6,%esp 985 sgdt (%esp) 986 addl $KERNBASE,2(%esp) 987 lgdt (%esp) 988 sidt (%esp) 989 addl $KERNBASE,2(%esp) 990 lidt (%esp) 991 addl $6,%esp 992 993 int $3 994 995bdb_commit_paging_exit: 996 ret 997 998#endif /* BDE_DEBUGGER */ 999