locore.s revision 49178
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 1.124 1999/06/18 14:32:13 bde 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 "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#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 414 415/* 416 * Signal trampoline, copied to top of user stack 417 */ 418NON_GPROF_ENTRY(sigcode) 419 call SIGF_HANDLER(%esp) 420 lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 421 /* copy at 8(%esp)) */ 422 pushl %eax 423 pushl %eax /* junk to fake return address */ 424 movl $SYS_sigreturn,%eax /* sigreturn() */ 425 LCALL(0x7,0) /* enter kernel with args on stack */ 426 hlt /* never gets here */ 427 ALIGN_TEXT 428_esigcode: 429 430 .data 431 .globl _szsigcode 432_szsigcode: 433 .long _esigcode-_sigcode 434 .text 435 436/********************************************************************** 437 * 438 * Recover the bootinfo passed to us from the boot program 439 * 440 */ 441recover_bootinfo: 442 /* 443 * This code is called in different ways depending on what loaded 444 * and started the kernel. This is used to detect how we get the 445 * arguments from the other code and what we do with them. 446 * 447 * Old disk boot blocks: 448 * (*btext)(howto, bootdev, cyloffset, esym); 449 * [return address == 0, and can NOT be returned to] 450 * [cyloffset was not supported by the FreeBSD boot code 451 * and always passed in as 0] 452 * [esym is also known as total in the boot code, and 453 * was never properly supported by the FreeBSD boot code] 454 * 455 * Old diskless netboot code: 456 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 457 * [return address != 0, and can NOT be returned to] 458 * If we are being booted by this code it will NOT work, 459 * so we are just going to halt if we find this case. 460 * 461 * New uniform boot code: 462 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 463 * [return address != 0, and can be returned to] 464 * 465 * There may seem to be a lot of wasted arguments in here, but 466 * that is so the newer boot code can still load very old kernels 467 * and old boot code can load new kernels. 468 */ 469 470 /* 471 * The old style disk boot blocks fake a frame on the stack and 472 * did an lret to get here. The frame on the stack has a return 473 * address of 0. 474 */ 475 cmpl $0,4(%ebp) 476 je olddiskboot 477 478 /* 479 * We have some form of return address, so this is either the 480 * old diskless netboot code, or the new uniform code. That can 481 * be detected by looking at the 5th argument, if it is 0 482 * we are being booted by the new uniform boot code. 483 */ 484 cmpl $0,24(%ebp) 485 je newboot 486 487 /* 488 * Seems we have been loaded by the old diskless boot code, we 489 * don't stand a chance of running as the diskless structure 490 * changed considerably between the two, so just halt. 491 */ 492 hlt 493 494 /* 495 * We have been loaded by the new uniform boot code. 496 * Let's check the bootinfo version, and if we do not understand 497 * it we return to the loader with a status of 1 to indicate this error 498 */ 499newboot: 500 movl 28(%ebp),%ebx /* &bootinfo.version */ 501 movl BI_VERSION(%ebx),%eax 502 cmpl $1,%eax /* We only understand version 1 */ 503 je 1f 504 movl $1,%eax /* Return status */ 505 leave 506 /* 507 * XXX this returns to our caller's caller (as is required) since 508 * we didn't set up a frame and our caller did. 509 */ 510 ret 511 5121: 513 /* 514 * If we have a kernelname copy it in 515 */ 516 movl BI_KERNELNAME(%ebx),%esi 517 cmpl $0,%esi 518 je 2f /* No kernelname */ 519 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 520 movl $R(_kernelname),%edi 521 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 522 je 1f 523 movb $'/',(%edi) 524 incl %edi 525 decl %ecx 5261: 527 cld 528 rep 529 movsb 530 5312: 532 /* 533 * Determine the size of the boot loader's copy of the bootinfo 534 * struct. This is impossible to do properly because old versions 535 * of the struct don't contain a size field and there are 2 old 536 * versions with the same version number. 537 */ 538 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 539 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 540 je got_bi_size /* no, sizeless version */ 541 movl BI_SIZE(%ebx),%ecx 542got_bi_size: 543 544 /* 545 * Copy the common part of the bootinfo struct 546 */ 547 movl %ebx,%esi 548 movl $R(_bootinfo),%edi 549 cmpl $BOOTINFO_SIZE,%ecx 550 jbe got_common_bi_size 551 movl $BOOTINFO_SIZE,%ecx 552got_common_bi_size: 553 cld 554 rep 555 movsb 556 557#ifdef NFS_ROOT 558#ifndef BOOTP_NFSV3 559 /* 560 * If we have a nfs_diskless structure copy it in 561 */ 562 movl BI_NFS_DISKLESS(%ebx),%esi 563 cmpl $0,%esi 564 je olddiskboot 565 movl $R(_nfs_diskless),%edi 566 movl $NFSDISKLESS_SIZE,%ecx 567 cld 568 rep 569 movsb 570 movl $R(_nfs_diskless_valid),%edi 571 movl $1,(%edi) 572#endif 573#endif 574 575 /* 576 * The old style disk boot. 577 * (*btext)(howto, bootdev, cyloffset, esym); 578 * Note that the newer boot code just falls into here to pick 579 * up howto and bootdev, cyloffset and esym are no longer used 580 */ 581olddiskboot: 582 movl 8(%ebp),%eax 583 movl %eax,R(_boothowto) 584 movl 12(%ebp),%eax 585 movl %eax,R(_bootdev) 586 587 ret 588 589 590/********************************************************************** 591 * 592 * Identify the CPU and initialize anything special about it 593 * 594 */ 595identify_cpu: 596 597 /* Try to toggle alignment check flag; does not exist on 386. */ 598 pushfl 599 popl %eax 600 movl %eax,%ecx 601 orl $PSL_AC,%eax 602 pushl %eax 603 popfl 604 pushfl 605 popl %eax 606 xorl %ecx,%eax 607 andl $PSL_AC,%eax 608 pushl %ecx 609 popfl 610 611 testl %eax,%eax 612 jnz try486 613 614 /* NexGen CPU does not have aligment check flag. */ 615 pushfl 616 movl $0x5555, %eax 617 xorl %edx, %edx 618 movl $2, %ecx 619 clc 620 divl %ecx 621 jz trynexgen 622 popfl 623 movl $CPU_386,R(_cpu) 624 jmp 3f 625 626trynexgen: 627 popfl 628 movl $CPU_NX586,R(_cpu) 629 movl $0x4778654e,R(_cpu_vendor) # store vendor string 630 movl $0x72446e65,R(_cpu_vendor+4) 631 movl $0x6e657669,R(_cpu_vendor+8) 632 movl $0,R(_cpu_vendor+12) 633 jmp 3f 634 635try486: /* Try to toggle identification flag; does not exist on early 486s. */ 636 pushfl 637 popl %eax 638 movl %eax,%ecx 639 xorl $PSL_ID,%eax 640 pushl %eax 641 popfl 642 pushfl 643 popl %eax 644 xorl %ecx,%eax 645 andl $PSL_ID,%eax 646 pushl %ecx 647 popfl 648 649 testl %eax,%eax 650 jnz trycpuid 651 movl $CPU_486,R(_cpu) 652 653 /* 654 * Check Cyrix CPU 655 * Cyrix CPUs do not change the undefined flags following 656 * execution of the divide instruction which divides 5 by 2. 657 * 658 * Note: CPUID is enabled on M2, so it passes another way. 659 */ 660 pushfl 661 movl $0x5555, %eax 662 xorl %edx, %edx 663 movl $2, %ecx 664 clc 665 divl %ecx 666 jnc trycyrix 667 popfl 668 jmp 3f /* You may use Intel CPU. */ 669 670trycyrix: 671 popfl 672 /* 673 * IBM Bluelighting CPU also doesn't change the undefined flags. 674 * Because IBM doesn't disclose the information for Bluelighting 675 * CPU, we couldn't distinguish it from Cyrix's (including IBM 676 * brand of Cyrix CPUs). 677 */ 678 movl $0x69727943,R(_cpu_vendor) # store vendor string 679 movl $0x736e4978,R(_cpu_vendor+4) 680 movl $0x64616574,R(_cpu_vendor+8) 681 jmp 3f 682 683trycpuid: /* Use the `cpuid' instruction. */ 684 xorl %eax,%eax 685 .byte 0x0f,0xa2 # cpuid 0 686 movl %eax,R(_cpu_high) # highest capability 687 movl %ebx,R(_cpu_vendor) # store vendor string 688 movl %edx,R(_cpu_vendor+4) 689 movl %ecx,R(_cpu_vendor+8) 690 movb $0,R(_cpu_vendor+12) 691 692 movl $1,%eax 693 .byte 0x0f,0xa2 # cpuid 1 694 movl %eax,R(_cpu_id) # store cpu_id 695 movl %edx,R(_cpu_feature) # store cpu_feature 696 rorl $8,%eax # extract family type 697 andl $15,%eax 698 cmpl $5,%eax 699 jae 1f 700 701 /* less than Pentium; must be 486 */ 702 movl $CPU_486,R(_cpu) 703 jmp 3f 7041: 705 /* a Pentium? */ 706 cmpl $5,%eax 707 jne 2f 708 movl $CPU_586,R(_cpu) 709 jmp 3f 7102: 711 /* Greater than Pentium...call it a Pentium Pro */ 712 movl $CPU_686,R(_cpu) 7133: 714 ret 715 716 717/********************************************************************** 718 * 719 * Create the first page directory and its page tables. 720 * 721 */ 722 723create_pagetables: 724 725 testl $CPUID_PGE, R(_cpu_feature) 726 jz 1f 727 movl %cr4, %eax 728 orl $CR4_PGE, %eax 729 movl %eax, %cr4 7301: 731 732/* Find end of kernel image (rounded up to a page boundary). */ 733 movl $R(_end),%esi 734 735/* include symbols if loaded and useful */ 736#ifdef DDB 737 movl R(_bootinfo+BI_ESYMTAB),%edi 738 testl %edi,%edi 739 je over_symalloc 740 movl %edi,%esi 741 movl $KERNBASE,%edi 742 addl %edi,R(_bootinfo+BI_SYMTAB) 743 addl %edi,R(_bootinfo+BI_ESYMTAB) 744over_symalloc: 745#endif 746 747/* If we are told where the end of the kernel space is, believe it. */ 748 movl R(_bootinfo+BI_KERNEND),%edi 749 testl %edi,%edi 750 je no_kernend 751 movl %edi,%esi 752no_kernend: 753 754 addl $PAGE_MASK,%esi 755 andl $~PAGE_MASK,%esi 756 movl %esi,R(_KERNend) /* save end of kernel */ 757 movl %esi,R(physfree) /* next free page is at end of kernel */ 758 759/* Allocate Kernel Page Tables */ 760 ALLOCPAGES(NKPT) 761 movl %esi,R(_KPTphys) 762 763/* Allocate Page Table Directory */ 764 ALLOCPAGES(1) 765 movl %esi,R(_IdlePTD) 766 767/* Allocate UPAGES */ 768 ALLOCPAGES(UPAGES) 769 movl %esi,R(p0upa) 770 addl $KERNBASE, %esi 771 movl %esi, R(_proc0paddr) 772 773 ALLOCPAGES(1) /* vm86/bios stack */ 774 movl %esi,R(vm86phystk) 775 776 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 777 movl %esi,R(_vm86pa) 778 addl $KERNBASE, %esi 779 movl %esi, R(_vm86paddr) 780 781#ifdef SMP 782/* Allocate cpu0's private data page */ 783 ALLOCPAGES(1) 784 movl %esi,R(cpu0pp) 785 addl $KERNBASE, %esi 786 movl %esi, R(_cpu0prvpage) /* relocated to KVM space */ 787 788/* Allocate SMP page table page */ 789 ALLOCPAGES(1) 790 movl %esi,R(SMPptpa) 791 addl $KERNBASE, %esi 792 movl %esi, R(_SMPpt) /* relocated to KVM space */ 793#endif /* SMP */ 794 795/* Map read-only from zero to the end of the kernel text section */ 796 xorl %eax, %eax 797#ifdef BDE_DEBUGGER 798/* If the debugger is present, actually map everything read-write. */ 799 cmpl $0,R(_bdb_exists) 800 jne map_read_write 801#endif 802 xorl %edx,%edx 803 804#if !defined(SMP) 805 testl $CPUID_PGE, R(_cpu_feature) 806 jz 2f 807 orl $PG_G,%edx 808#endif 809 8102: movl $R(_etext),%ecx 811 addl $PAGE_MASK,%ecx 812 shrl $PAGE_SHIFT,%ecx 813 fillkptphys(%edx) 814 815/* Map read-write, data, bss and symbols */ 816 movl $R(_etext),%eax 817 addl $PAGE_MASK, %eax 818 andl $~PAGE_MASK, %eax 819map_read_write: 820 movl $PG_RW,%edx 821#if !defined(SMP) 822 testl $CPUID_PGE, R(_cpu_feature) 823 jz 1f 824 orl $PG_G,%edx 825#endif 826 8271: movl R(_KERNend),%ecx 828 subl %eax,%ecx 829 shrl $PAGE_SHIFT,%ecx 830 fillkptphys(%edx) 831 832/* Map page directory. */ 833 movl R(_IdlePTD), %eax 834 movl $1, %ecx 835 fillkptphys($PG_RW) 836 837/* Map proc0's UPAGES in the physical way ... */ 838 movl R(p0upa), %eax 839 movl $UPAGES, %ecx 840 fillkptphys($PG_RW) 841 842/* Map ISA hole */ 843 movl $ISA_HOLE_START, %eax 844 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 845 fillkptphys($PG_RW) 846 847/* Map space for the vm86 region */ 848 movl R(vm86phystk), %eax 849 movl $4, %ecx 850 fillkptphys($PG_RW) 851 852/* Map page 0 into the vm86 page table */ 853 movl $0, %eax 854 movl $0, %ebx 855 movl $1, %ecx 856 fillkpt(R(_vm86pa), $PG_RW|PG_U) 857 858/* ...likewise for the ISA hole */ 859 movl $ISA_HOLE_START, %eax 860 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 861 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 862 fillkpt(R(_vm86pa), $PG_RW|PG_U) 863 864#ifdef SMP 865/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 866 movl R(cpu0pp), %eax 867 movl $1, %ecx 868 fillkptphys($PG_RW) 869 870/* Map SMP page table page into global kmem FWIW */ 871 movl R(SMPptpa), %eax 872 movl $1, %ecx 873 fillkptphys($PG_RW) 874 875/* Map the private page into the SMP page table */ 876 movl R(cpu0pp), %eax 877 movl $0, %ebx /* pte offset = 0 */ 878 movl $1, %ecx /* one private page coming right up */ 879 fillkpt(R(SMPptpa), $PG_RW) 880 881/* ... and put the page table table in the pde. */ 882 movl R(SMPptpa), %eax 883 movl $MPPTDI, %ebx 884 movl $1, %ecx 885 fillkpt(R(_IdlePTD), $PG_RW) 886 887/* Fakeup VA for the local apic to allow early traps. */ 888 ALLOCPAGES(1) 889 movl %esi, %eax 890 movl $(NPTEPG-1), %ebx /* pte offset = NTEPG-1 */ 891 movl $1, %ecx /* one private pt coming right up */ 892 fillkpt(R(SMPptpa), $PG_RW) 893 894/* Initialize mp lock to allow early traps */ 895 movl $1, R(_mp_lock) 896#endif /* SMP */ 897 898/* install a pde for temporary double map of bottom of VA */ 899 movl R(_KPTphys), %eax 900 xorl %ebx, %ebx 901 movl $1, %ecx 902 fillkpt(R(_IdlePTD), $PG_RW) 903 904/* install pde's for pt's */ 905 movl R(_KPTphys), %eax 906 movl $KPTDI, %ebx 907 movl $NKPT, %ecx 908 fillkpt(R(_IdlePTD), $PG_RW) 909 910/* install a pde recursively mapping page directory as a page table */ 911 movl R(_IdlePTD), %eax 912 movl $PTDPTDI, %ebx 913 movl $1,%ecx 914 fillkpt(R(_IdlePTD), $PG_RW) 915 916 ret 917 918#ifdef BDE_DEBUGGER 919bdb_prepare_paging: 920 cmpl $0,R(_bdb_exists) 921 je bdb_prepare_paging_exit 922 923 subl $6,%esp 924 925 /* 926 * Copy and convert debugger entries from the bootstrap gdt and idt 927 * to the kernel gdt and idt. Everything is still in low memory. 928 * Tracing continues to work after paging is enabled because the 929 * low memory addresses remain valid until everything is relocated. 930 * However, tracing through the setidt() that initializes the trace 931 * trap will crash. 932 */ 933 sgdt (%esp) 934 movl 2(%esp),%esi /* base address of bootstrap gdt */ 935 movl $R(_gdt),%edi 936 movl %edi,2(%esp) /* prepare to load kernel gdt */ 937 movl $8*18/4,%ecx 938 cld 939 rep /* copy gdt */ 940 movsl 941 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 942 movb $0x92,-8+5(%edi) 943 lgdt (%esp) 944 945 sidt (%esp) 946 movl 2(%esp),%esi /* base address of current idt */ 947 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 948 movw 8(%esi),%ax 949 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 950 movl 8+2(%esi),%eax 951 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 952 movl 24+4(%esi),%eax /* same for bpt descriptor */ 953 movw 24(%esi),%ax 954 movl %eax,R(bdb_bpt_ljmp+1) 955 movl 24+2(%esi),%eax 956 movw %ax,R(bdb_bpt_ljmp+5) 957 movl R(_idt),%edi 958 movl %edi,2(%esp) /* prepare to load kernel idt */ 959 movl $8*4/4,%ecx 960 cld 961 rep /* copy idt */ 962 movsl 963 lidt (%esp) 964 965 addl $6,%esp 966 967bdb_prepare_paging_exit: 968 ret 969 970/* Relocate debugger gdt entries and gdt and idt pointers. */ 971bdb_commit_paging: 972 cmpl $0,_bdb_exists 973 je bdb_commit_paging_exit 974 975 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 976 movl $9,%ecx 977reloc_gdt: 978 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 979 addl $8,%eax /* now KERNBASE>>24 */ 980 loop reloc_gdt 981 982 subl $6,%esp 983 sgdt (%esp) 984 addl $KERNBASE,2(%esp) 985 lgdt (%esp) 986 sidt (%esp) 987 addl $KERNBASE,2(%esp) 988 lidt (%esp) 989 addl $6,%esp 990 991 int $3 992 993bdb_commit_paging_exit: 994 ret 995 996#endif /* BDE_DEBUGGER */ 997