locore.s revision 35072
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 1.106 1998/04/04 13:24:11 phk Exp $ 38 * 39 * originally from: locore.s, by William F. Jolitz 40 * 41 * Substantially rewritten by David Greenman, Rod Grimes, 42 * Bruce Evans, Wolfgang Solfrank, Poul-Henning Kamp 43 * and many others. 44 */ 45 46#include "apm.h" 47#include "opt_bootp.h" 48#include "opt_cpu.h" 49#include "opt_ddb.h" 50#include "opt_nfs.h" 51#include "opt_userconfig.h" 52#include "opt_vm86.h" 53 54#include <sys/syscall.h> 55#include <sys/reboot.h> 56 57#include <machine/asmacros.h> 58#include <machine/cputypes.h> 59#include <machine/psl.h> 60#include <machine/pmap.h> 61#include <machine/specialreg.h> 62 63#include "assym.s" 64 65/* 66 * XXX 67 * 68 * Note: This version greatly munged to avoid various assembler errors 69 * that may be fixed in newer versions of gas. Perhaps newer versions 70 * will have more pleasant appearance. 71 */ 72 73/* 74 * PTmap is recursive pagemap at top of virtual address space. 75 * Within PTmap, the page directory can be found (third indirection). 76 */ 77 .globl _PTmap,_PTD,_PTDpde 78 .set _PTmap,(PTDPTDI << PDRSHIFT) 79 .set _PTD,_PTmap + (PTDPTDI * PAGE_SIZE) 80 .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 81 82/* 83 * APTmap, APTD is the alternate recursive pagemap. 84 * It's used when modifying another process's page tables. 85 */ 86 .globl _APTmap,_APTD,_APTDpde 87 .set _APTmap,APTDPTDI << PDRSHIFT 88 .set _APTD,_APTmap + (APTDPTDI * PAGE_SIZE) 89 .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 90 91/* 92 * Globals 93 */ 94 .data 95 ALIGN_DATA /* just to be sure */ 96 97 .globl HIDENAME(tmpstk) 98 .space 0x2000 /* space for tmpstk - temporary stack */ 99HIDENAME(tmpstk): 100 101 .globl _boothowto,_bootdev 102 103 .globl _cpu,_cpu_vendor,_cpu_id,_bootinfo 104 .globl _cpu_high, _cpu_feature 105 106_cpu: .long 0 /* are we 386, 386sx, or 486 */ 107_cpu_id: .long 0 /* stepping ID */ 108_cpu_high: .long 0 /* highest arg to CPUID */ 109_cpu_feature: .long 0 /* features */ 110_cpu_vendor: .space 20 /* CPU origin code */ 111_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 112 113_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 114physfree: .long 0 /* phys addr of next free page */ 115 116#ifdef SMP 117cpu0pp: .long 0 /* phys addr cpu0 private pg */ 118cpu0pt: .long 0 /* phys addr cpu0 private pt */ 119 120 .globl _cpu0prvpage,_cpu0prvpt 121_cpu0prvpage: .long 0 /* relocated version */ 122_cpu0prvpt: .long 0 /* relocated version */ 123#endif /* SMP */ 124 125 .globl _IdlePTD 126_IdlePTD: .long 0 /* phys addr of kernel PTD */ 127 128#ifdef SMP 129 .globl _KPTphys 130#endif 131_KPTphys: .long 0 /* phys addr of kernel page tables */ 132 133 .globl _proc0paddr 134_proc0paddr: .long 0 /* address of proc 0 address space */ 135p0upa: .long 0 /* phys addr of proc0's UPAGES */ 136 137#ifdef VM86 138 .globl _vm86paddr, _vm86pa 139_vm86paddr: .long 0 /* address of vm86 region */ 140_vm86pa: .long 0 /* phys addr of vm86 region */ 141#endif 142 143#ifdef BDE_DEBUGGER 144 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 145_bdb_exists: .long 0 146#endif 147 148 149/********************************************************************** 150 * 151 * Some handy macros 152 * 153 */ 154 155#define R(foo) ((foo)-KERNBASE) 156 157#define ALLOCPAGES(foo) \ 158 movl R(physfree), %esi ; \ 159 movl $((foo)*PAGE_SIZE), %eax ; \ 160 addl %esi, %eax ; \ 161 movl %eax, R(physfree) ; \ 162 movl %esi, %edi ; \ 163 movl $((foo)*PAGE_SIZE),%ecx ; \ 164 xorl %eax,%eax ; \ 165 cld ; \ 166 rep ; \ 167 stosb 168 169/* 170 * fillkpt 171 * eax = page frame address 172 * ebx = index into page table 173 * ecx = how many pages to map 174 * base = base address of page dir/table 175 * prot = protection bits 176 */ 177#define fillkpt(base, prot) \ 178 shll $2,%ebx ; \ 179 addl base,%ebx ; \ 180 orl $PG_V,%eax ; \ 181 orl prot,%eax ; \ 1821: movl %eax,(%ebx) ; \ 183 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 184 addl $4,%ebx ; /* next pte */ \ 185 loop 1b 186 187/* 188 * fillkptphys(prot) 189 * eax = physical address 190 * ecx = how many pages to map 191 * prot = protection bits 192 */ 193#define fillkptphys(prot) \ 194 movl %eax, %ebx ; \ 195 shrl $PAGE_SHIFT, %ebx ; \ 196 fillkpt(R(_KPTphys), prot) 197 198 .text 199/********************************************************************** 200 * 201 * This is where the bootblocks start us, set the ball rolling... 202 * 203 */ 204NON_GPROF_ENTRY(btext) 205 206#ifdef PC98 207 jmp 1f 208 .globl _pc98_system_parameter 209 .org 0x400 210_pc98_system_parameter: 211 .space 0x240 /* BIOS parameter block */ 2121: 213 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 214 movl $0xa1000,%esi 215 movl $0x100000,%edi 216 movl $0x0630,%ecx 217 cld 218 rep 219 movsb 220#else /* IBM-PC */ 221#ifdef BDE_DEBUGGER 222#ifdef BIOS_STEALS_3K 223 cmpl $0x0375c339,0x95504 224#else 225 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 226#endif 227 jne 1f 228 movb $1,R(_bdb_exists) 2291: 230#endif 231 232/* Tell the bios to warmboot next time */ 233 movw $0x1234,0x472 234#endif /* PC98 */ 235 236/* Set up a real frame in case the double return in newboot is executed. */ 237 pushl %ebp 238 movl %esp, %ebp 239 240/* Don't trust what the BIOS gives for eflags. */ 241 pushl $PSL_KERNEL 242 popfl 243 244/* 245 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 246 * to set %cs, %ds, %es and %ss. 247 */ 248 mov %ds, %ax 249 mov %ax, %fs 250 mov %ax, %gs 251 252 call recover_bootinfo 253 254/* Get onto a stack that we can trust. */ 255/* 256 * XXX this step is delayed in case recover_bootinfo needs to return via 257 * the old stack, but it need not be, since recover_bootinfo actually 258 * returns via the old frame. 259 */ 260 movl $R(HIDENAME(tmpstk)),%esp 261 262#ifdef PC98 263 testb $0x02,0x100620 /* pc98_machine_type & M_EPSON_PC98 */ 264 jz 3f 265 cmpb $0x0b,0x100624 /* epson_machine_id <= 0x0b */ 266 ja 3f 267 268 /* count up memory */ 269 movl $0x100000,%eax /* next, talley remaining memory */ 270 movl $0xFFF-0x100,%ecx 2711: movl 0(%eax),%ebx /* save location to check */ 272 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 273 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 274 jne 2f 275 movl %ebx,0(%eax) /* restore memory */ 276 addl $PAGE_SIZE,%eax 277 loop 1b 2782: subl $0x100000,%eax 279 shrl $17,%eax 280 movb %al,0x100401 2813: 282#endif 283 284 call identify_cpu 285 286/* clear bss */ 287/* 288 * XXX this should be done a little earlier. 289 * 290 * XXX we don't check that there is memory for our bss and page tables 291 * before using it. 292 * 293 * XXX the boot program somewhat bogusly clears the bss. We still have 294 * to do it in case we were unzipped by kzipboot. Then the boot program 295 * only clears kzipboot's bss. 296 * 297 * XXX the gdt and idt are still somewhere in the boot program. We 298 * depend on the convention that the boot program is below 1MB and we 299 * are above 1MB to keep the gdt and idt away from the bss and page 300 * tables. The idt is only used if BDE_DEBUGGER is enabled. 301 */ 302 movl $R(_end),%ecx 303 movl $R(_edata),%edi 304 subl %edi,%ecx 305 xorl %eax,%eax 306 cld 307 rep 308 stosb 309 310#if NAPM > 0 311/* 312 * XXX it's not clear that APM can live in the current environonment. 313 * Only pc-relative addressing works. 314 */ 315 call _apm_setup 316#endif 317 318 call create_pagetables 319 320#ifdef VM86 321/* 322 * If the CPU has support for VME, turn it on. 323 */ 324 testl $CPUID_VME, R(_cpu_feature) 325 jz 1f 326 movl %cr4, %eax 327 orl $CR4_VME, %eax 328 movl %eax, %cr4 3291: 330#endif /* VM86 */ 331 332#ifdef BDE_DEBUGGER 333/* 334 * Adjust as much as possible for paging before enabling paging so that the 335 * adjustments can be traced. 336 */ 337 call bdb_prepare_paging 338#endif 339 340/* Now enable paging */ 341 movl R(_IdlePTD), %eax 342 movl %eax,%cr3 /* load ptd addr into mmu */ 343 movl %cr0,%eax /* get control word */ 344 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 345 movl %eax,%cr0 /* and let's page NOW! */ 346 347#ifdef BDE_DEBUGGER 348/* 349 * Complete the adjustments for paging so that we can keep tracing through 350 * initi386() after the low (physical) addresses for the gdt and idt become 351 * invalid. 352 */ 353 call bdb_commit_paging 354#endif 355 356 pushl $begin /* jump to high virtualized address */ 357 ret 358 359/* now running relocated at KERNBASE where the system is linked to run */ 360begin: 361 /* set up bootstrap stack */ 362 movl _proc0paddr,%esp /* location of in-kernel pages */ 363 addl $UPAGES*PAGE_SIZE,%esp /* bootstrap stack end location */ 364 xorl %eax,%eax /* mark end of frames */ 365 movl %eax,%ebp 366 movl _proc0paddr,%eax 367 movl _IdlePTD, %esi 368 movl %esi,PCB_CR3(%eax) 369 movl $_proc0,_curproc 370 371 movl physfree, %esi 372 pushl %esi /* value of first for init386(first) */ 373 call _init386 /* wire 386 chip for unix operation */ 374 popl %esi 375 376 .globl __ucodesel,__udatasel 377 378 pushl $0 /* unused */ 379 pushl __udatasel /* ss */ 380 pushl $0 /* esp - filled in by execve() */ 381 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 382 pushl __ucodesel /* cs */ 383 pushl $0 /* eip - filled in by execve() */ 384 subl $(12*4),%esp /* space for rest of registers */ 385 386 pushl %esp /* call main with frame pointer */ 387 call _main /* autoconfiguration, mountroot etc */ 388 389 hlt /* never returns to here */ 390 391/* 392 * When starting init, call this to configure the process for user 393 * mode. This will be inherited by other processes. 394 */ 395NON_GPROF_ENTRY(prepare_usermode) 396 /* 397 * Now we've run main() and determined what cpu-type we are, we can 398 * enable write protection and alignment checking on i486 cpus and 399 * above. 400 */ 401#if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU) 402 cmpl $CPUCLASS_386,_cpu_class 403 je 1f 404 movl %cr0,%eax /* get control word */ 405 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 406 movl %eax,%cr0 /* and do it */ 4071: 408#endif 409 /* 410 * on return from main(), we are process 1 411 * set up address space and stack so that we can 'return' to user mode 412 */ 413 movl __ucodesel,%eax 414 movl __udatasel,%ecx 415 416#if 0 417 movl %cx,%ds 418#endif 419 movl %cx,%es 420 movl %ax,%fs /* double map cs to fs */ 421 movl %cx,%gs /* and ds to gs */ 422 ret /* goto user! */ 423 424 425#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 426 427/* 428 * Signal trampoline, copied to top of user stack 429 */ 430NON_GPROF_ENTRY(sigcode) 431 call SIGF_HANDLER(%esp) 432 lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 433 /* copy at 8(%esp)) */ 434 pushl %eax 435 pushl %eax /* junk to fake return address */ 436 movl $SYS_sigreturn,%eax /* sigreturn() */ 437 LCALL(0x7,0) /* enter kernel with args on stack */ 438 hlt /* never gets here */ 439 ALIGN_TEXT 440_esigcode: 441 442 .data 443 .globl _szsigcode 444_szsigcode: 445 .long _esigcode-_sigcode 446 .text 447 448/********************************************************************** 449 * 450 * Recover the bootinfo passed to us from the boot program 451 * 452 */ 453recover_bootinfo: 454 /* 455 * This code is called in different ways depending on what loaded 456 * and started the kernel. This is used to detect how we get the 457 * arguments from the other code and what we do with them. 458 * 459 * Old disk boot blocks: 460 * (*btext)(howto, bootdev, cyloffset, esym); 461 * [return address == 0, and can NOT be returned to] 462 * [cyloffset was not supported by the FreeBSD boot code 463 * and always passed in as 0] 464 * [esym is also known as total in the boot code, and 465 * was never properly supported by the FreeBSD boot code] 466 * 467 * Old diskless netboot code: 468 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 469 * [return address != 0, and can NOT be returned to] 470 * If we are being booted by this code it will NOT work, 471 * so we are just going to halt if we find this case. 472 * 473 * New uniform boot code: 474 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 475 * [return address != 0, and can be returned to] 476 * 477 * There may seem to be a lot of wasted arguments in here, but 478 * that is so the newer boot code can still load very old kernels 479 * and old boot code can load new kernels. 480 */ 481 482 /* 483 * The old style disk boot blocks fake a frame on the stack and 484 * did an lret to get here. The frame on the stack has a return 485 * address of 0. 486 */ 487 cmpl $0,4(%ebp) 488 je olddiskboot 489 490 /* 491 * We have some form of return address, so this is either the 492 * old diskless netboot code, or the new uniform code. That can 493 * be detected by looking at the 5th argument, if it is 0 494 * we are being booted by the new uniform boot code. 495 */ 496 cmpl $0,24(%ebp) 497 je newboot 498 499 /* 500 * Seems we have been loaded by the old diskless boot code, we 501 * don't stand a chance of running as the diskless structure 502 * changed considerably between the two, so just halt. 503 */ 504 hlt 505 506 /* 507 * We have been loaded by the new uniform boot code. 508 * Let's check the bootinfo version, and if we do not understand 509 * it we return to the loader with a status of 1 to indicate this error 510 */ 511newboot: 512 movl 28(%ebp),%ebx /* &bootinfo.version */ 513 movl BI_VERSION(%ebx),%eax 514 cmpl $1,%eax /* We only understand version 1 */ 515 je 1f 516 movl $1,%eax /* Return status */ 517 leave 518 /* 519 * XXX this returns to our caller's caller (as is required) since 520 * we didn't set up a frame and our caller did. 521 */ 522 ret 523 5241: 525 /* 526 * If we have a kernelname copy it in 527 */ 528 movl BI_KERNELNAME(%ebx),%esi 529 cmpl $0,%esi 530 je 2f /* No kernelname */ 531 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 532 movl $R(_kernelname),%edi 533 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 534 je 1f 535 movb $'/',(%edi) 536 incl %edi 537 decl %ecx 5381: 539 cld 540 rep 541 movsb 542 5432: 544 /* 545 * Determine the size of the boot loader's copy of the bootinfo 546 * struct. This is impossible to do properly because old versions 547 * of the struct don't contain a size field and there are 2 old 548 * versions with the same version number. 549 */ 550 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 551 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 552 je got_bi_size /* no, sizeless version */ 553 movl BI_SIZE(%ebx),%ecx 554got_bi_size: 555 556 /* 557 * Copy the common part of the bootinfo struct 558 */ 559 movl %ebx,%esi 560 movl $R(_bootinfo),%edi 561 cmpl $BOOTINFO_SIZE,%ecx 562 jbe got_common_bi_size 563 movl $BOOTINFO_SIZE,%ecx 564got_common_bi_size: 565 cld 566 rep 567 movsb 568 569#ifdef NFS 570#ifndef BOOTP_NFSV3 571 /* 572 * If we have a nfs_diskless structure copy it in 573 */ 574 movl BI_NFS_DISKLESS(%ebx),%esi 575 cmpl $0,%esi 576 je olddiskboot 577 movl $R(_nfs_diskless),%edi 578 movl $NFSDISKLESS_SIZE,%ecx 579 cld 580 rep 581 movsb 582 movl $R(_nfs_diskless_valid),%edi 583 movl $1,(%edi) 584#endif 585#endif 586 587 /* 588 * The old style disk boot. 589 * (*btext)(howto, bootdev, cyloffset, esym); 590 * Note that the newer boot code just falls into here to pick 591 * up howto and bootdev, cyloffset and esym are no longer used 592 */ 593olddiskboot: 594 movl 8(%ebp),%eax 595 movl %eax,R(_boothowto) 596 movl 12(%ebp),%eax 597 movl %eax,R(_bootdev) 598 599#if defined(USERCONFIG_BOOT) && defined(USERCONFIG) 600 movl $0x10200, %esi 601 movl $R(_userconfig_from_boot),%edi 602 movl $512,%ecx 603 cld 604 rep 605 movsb 606#endif /* USERCONFIG_BOOT */ 607 608 ret 609 610 611/********************************************************************** 612 * 613 * Identify the CPU and initialize anything special about it 614 * 615 */ 616identify_cpu: 617 618 /* Try to toggle alignment check flag; does not exist on 386. */ 619 pushfl 620 popl %eax 621 movl %eax,%ecx 622 orl $PSL_AC,%eax 623 pushl %eax 624 popfl 625 pushfl 626 popl %eax 627 xorl %ecx,%eax 628 andl $PSL_AC,%eax 629 pushl %ecx 630 popfl 631 632 testl %eax,%eax 633 jnz try486 634 635 /* NexGen CPU does not have aligment check flag. */ 636 pushfl 637 movl $0x5555, %eax 638 xorl %edx, %edx 639 movl $2, %ecx 640 clc 641 divl %ecx 642 jz trynexgen 643 popfl 644 movl $CPU_386,R(_cpu) 645 jmp 3f 646 647trynexgen: 648 popfl 649 movl $CPU_NX586,R(_cpu) 650 movl $0x4778654e,R(_cpu_vendor) # store vendor string 651 movl $0x72446e65,R(_cpu_vendor+4) 652 movl $0x6e657669,R(_cpu_vendor+8) 653 movl $0,R(_cpu_vendor+12) 654 jmp 3f 655 656try486: /* Try to toggle identification flag; does not exist on early 486s. */ 657 pushfl 658 popl %eax 659 movl %eax,%ecx 660 xorl $PSL_ID,%eax 661 pushl %eax 662 popfl 663 pushfl 664 popl %eax 665 xorl %ecx,%eax 666 andl $PSL_ID,%eax 667 pushl %ecx 668 popfl 669 670 testl %eax,%eax 671 jnz trycpuid 672 movl $CPU_486,R(_cpu) 673 674 /* 675 * Check Cyrix CPU 676 * Cyrix CPUs do not change the undefined flags following 677 * execution of the divide instruction which divides 5 by 2. 678 * 679 * Note: CPUID is enabled on M2, so it passes another way. 680 */ 681 pushfl 682 movl $0x5555, %eax 683 xorl %edx, %edx 684 movl $2, %ecx 685 clc 686 divl %ecx 687 jnc trycyrix 688 popfl 689 jmp 3f /* You may use Intel CPU. */ 690 691trycyrix: 692 popfl 693 /* 694 * IBM Bluelighting CPU also doesn't change the undefined flags. 695 * Because IBM doesn't disclose the information for Bluelighting 696 * CPU, we couldn't distinguish it from Cyrix's (including IBM 697 * brand of Cyrix CPUs). 698 */ 699 movl $0x69727943,R(_cpu_vendor) # store vendor string 700 movl $0x736e4978,R(_cpu_vendor+4) 701 movl $0x64616574,R(_cpu_vendor+8) 702 jmp 3f 703 704trycpuid: /* Use the `cpuid' instruction. */ 705 xorl %eax,%eax 706 .byte 0x0f,0xa2 # cpuid 0 707 movl %eax,R(_cpu_high) # highest capability 708 movl %ebx,R(_cpu_vendor) # store vendor string 709 movl %edx,R(_cpu_vendor+4) 710 movl %ecx,R(_cpu_vendor+8) 711 movb $0,R(_cpu_vendor+12) 712 713 movl $1,%eax 714 .byte 0x0f,0xa2 # cpuid 1 715 movl %eax,R(_cpu_id) # store cpu_id 716 movl %edx,R(_cpu_feature) # store cpu_feature 717 rorl $8,%eax # extract family type 718 andl $15,%eax 719 cmpl $5,%eax 720 jae 1f 721 722 /* less than Pentium; must be 486 */ 723 movl $CPU_486,R(_cpu) 724 jmp 3f 7251: 726 /* a Pentium? */ 727 cmpl $5,%eax 728 jne 2f 729 movl $CPU_586,R(_cpu) 730 jmp 3f 7312: 732 /* Greater than Pentium...call it a Pentium Pro */ 733 movl $CPU_686,R(_cpu) 7343: 735 ret 736 737 738/********************************************************************** 739 * 740 * Create the first page directory and its page tables. 741 * 742 */ 743 744create_pagetables: 745 746 testl $CPUID_PGE, R(_cpu_feature) 747 jz 1f 748 movl %cr4, %eax 749 orl $CR4_PGE, %eax 750 movl %eax, %cr4 7511: 752 753/* Find end of kernel image (rounded up to a page boundary). */ 754 movl $R(_end),%esi 755 756/* include symbols in "kernel image" if they are loaded and useful */ 757#ifdef DDB 758 movl R(_bootinfo+BI_ESYMTAB),%edi 759 testl %edi,%edi 760 je over_symalloc 761 movl %edi,%esi 762 movl $KERNBASE,%edi 763 addl %edi,R(_bootinfo+BI_SYMTAB) 764 addl %edi,R(_bootinfo+BI_ESYMTAB) 765over_symalloc: 766#endif 767 768 addl $PAGE_MASK,%esi 769 andl $~PAGE_MASK,%esi 770 movl %esi,R(_KERNend) /* save end of kernel */ 771 movl %esi,R(physfree) /* next free page is at end of kernel */ 772 773/* Allocate Kernel Page Tables */ 774 ALLOCPAGES(NKPT) 775 movl %esi,R(_KPTphys) 776 777/* Allocate Page Table Directory */ 778 ALLOCPAGES(1) 779 movl %esi,R(_IdlePTD) 780 781/* Allocate UPAGES */ 782 ALLOCPAGES(UPAGES) 783 movl %esi,R(p0upa) 784 addl $KERNBASE, %esi 785 movl %esi, R(_proc0paddr) 786 787#ifdef VM86 788 ALLOCPAGES(4) /* IOPAGES + ext + stack */ 789 movl %esi,R(_vm86pa) 790 addl $KERNBASE, %esi 791 movl %esi, R(_vm86paddr) 792#endif /* VM86 */ 793 794#ifdef SMP 795/* Allocate cpu0's private data page */ 796 ALLOCPAGES(1) 797 movl %esi,R(cpu0pp) 798 addl $KERNBASE, %esi 799 movl %esi, R(_cpu0prvpage) /* relocated to KVM space */ 800 801/* Allocate cpu0's private page table for mapping priv page, apic, etc */ 802 ALLOCPAGES(1) 803 movl %esi,R(cpu0pt) 804 addl $KERNBASE, %esi 805 movl %esi, R(_cpu0prvpt) /* relocated to KVM space */ 806#endif /* SMP */ 807 808/* Map read-only from zero to the end of the kernel text section */ 809 xorl %eax, %eax 810#ifdef BDE_DEBUGGER 811/* If the debugger is present, actually map everything read-write. */ 812 cmpl $0,R(_bdb_exists) 813 jne map_read_write 814#endif 815 xorl %edx,%edx 816 817#if !defined(SMP) 818 testl $CPUID_PGE, R(_cpu_feature) 819 jz 2f 820 orl $PG_G,%edx 821#endif 822 8232: movl $R(_etext),%ecx 824 addl $PAGE_MASK,%ecx 825 shrl $PAGE_SHIFT,%ecx 826 fillkptphys(%edx) 827 828/* Map read-write, data, bss and symbols */ 829 movl $R(_etext),%eax 830 addl $PAGE_MASK, %eax 831 andl $~PAGE_MASK, %eax 832map_read_write: 833 movl $PG_RW,%edx 834#if !defined(SMP) 835 testl $CPUID_PGE, R(_cpu_feature) 836 jz 1f 837 orl $PG_G,%edx 838#endif 839 8401: movl R(_KERNend),%ecx 841 subl %eax,%ecx 842 shrl $PAGE_SHIFT,%ecx 843 fillkptphys(%edx) 844 845/* Map page directory. */ 846 movl R(_IdlePTD), %eax 847 movl $1, %ecx 848 fillkptphys($PG_RW) 849 850/* Map proc0's UPAGES in the physical way ... */ 851 movl R(p0upa), %eax 852 movl $UPAGES, %ecx 853 fillkptphys($PG_RW) 854 855/* Map ISA hole */ 856 movl $ISA_HOLE_START, %eax 857 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 858 fillkptphys($PG_RW) 859 860#ifdef VM86 861/* Map space for the vm86 region */ 862 movl R(_vm86pa), %eax 863 movl $4, %ecx 864 fillkptphys($PG_RW) 865 866/* Map page 0 into the vm86 page table */ 867 movl $0, %eax 868 movl $0, %ebx 869 movl $1, %ecx 870 fillkpt(R(_vm86pa), $PG_RW|PG_U) 871 872/* ...likewise for the ISA hole */ 873 movl $ISA_HOLE_START, %eax 874 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 875 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 876 fillkpt(R(_vm86pa), $PG_RW|PG_U) 877#endif /* VM86 */ 878 879#ifdef SMP 880/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 881 movl R(cpu0pp), %eax 882 movl $1, %ecx 883 fillkptphys($PG_RW) 884 885/* Map cpu0's private page table into global kmem FWIW */ 886 movl R(cpu0pt), %eax 887 movl $1, %ecx 888 fillkptphys($PG_RW) 889 890/* Map the private page into the private page table into private space */ 891 movl R(cpu0pp), %eax 892 movl $0, %ebx /* pte offset = 0 */ 893 movl $1, %ecx /* one private page coming right up */ 894 fillkpt(R(cpu0pt), $PG_RW) 895 896/* Map the page table page into private space */ 897 movl R(cpu0pt), %eax 898 movl $1, %ebx /* pte offset = 1 */ 899 movl $1, %ecx /* one private pt coming right up */ 900 fillkpt(R(cpu0pt), $PG_RW) 901 902/* ... and put the page table table in the pde. */ 903 movl R(cpu0pt), %eax 904 movl $MPPTDI, %ebx 905 movl $1, %ecx 906 fillkpt(R(_IdlePTD), $PG_RW) 907 908/* Fakeup VA for the local apic to allow early traps. */ 909 ALLOCPAGES(1) 910 movl %esi, %eax 911 movl $2, %ebx /* pte offset = 2 */ 912 movl $1, %ecx /* one private pt coming right up */ 913 fillkpt(R(cpu0pt), $PG_RW) 914 915/* Initialize mp lock to allow early traps */ 916 movl $1, R(_mp_lock) 917 918/* Initialize my_idlePTD to IdlePTD */ 919 movl R(cpu0pp), %eax 920 movl R(_IdlePTD), %ecx 921 movl %ecx,GD_MY_IDLEPTD(%eax) 922 923#endif /* SMP */ 924 925/* install a pde for temporary double map of bottom of VA */ 926 movl R(_KPTphys), %eax 927 xorl %ebx, %ebx 928 movl $1, %ecx 929 fillkpt(R(_IdlePTD), $PG_RW) 930 931/* install pde's for pt's */ 932 movl R(_KPTphys), %eax 933 movl $KPTDI, %ebx 934 movl $NKPT, %ecx 935 fillkpt(R(_IdlePTD), $PG_RW) 936 937/* install a pde recursively mapping page directory as a page table */ 938 movl R(_IdlePTD), %eax 939 movl $PTDPTDI, %ebx 940 movl $1,%ecx 941 fillkpt(R(_IdlePTD), $PG_RW) 942 943 ret 944 945#ifdef BDE_DEBUGGER 946bdb_prepare_paging: 947 cmpl $0,R(_bdb_exists) 948 je bdb_prepare_paging_exit 949 950 subl $6,%esp 951 952 /* 953 * Copy and convert debugger entries from the bootstrap gdt and idt 954 * to the kernel gdt and idt. Everything is still in low memory. 955 * Tracing continues to work after paging is enabled because the 956 * low memory addresses remain valid until everything is relocated. 957 * However, tracing through the setidt() that initializes the trace 958 * trap will crash. 959 */ 960 sgdt (%esp) 961 movl 2(%esp),%esi /* base address of bootstrap gdt */ 962 movl $R(_gdt),%edi 963 movl %edi,2(%esp) /* prepare to load kernel gdt */ 964 movl $8*18/4,%ecx 965 cld 966 rep /* copy gdt */ 967 movsl 968 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 969 movb $0x92,-8+5(%edi) 970 lgdt (%esp) 971 972 sidt (%esp) 973 movl 2(%esp),%esi /* base address of current idt */ 974 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 975 movw 8(%esi),%ax 976 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 977 movl 8+2(%esi),%eax 978 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 979 movl 24+4(%esi),%eax /* same for bpt descriptor */ 980 movw 24(%esi),%ax 981 movl %eax,R(bdb_bpt_ljmp+1) 982 movl 24+2(%esi),%eax 983 movw %ax,R(bdb_bpt_ljmp+5) 984 movl $R(_idt),%edi 985 movl %edi,2(%esp) /* prepare to load kernel idt */ 986 movl $8*4/4,%ecx 987 cld 988 rep /* copy idt */ 989 movsl 990 lidt (%esp) 991 992 addl $6,%esp 993 994bdb_prepare_paging_exit: 995 ret 996 997/* Relocate debugger gdt entries and gdt and idt pointers. */ 998bdb_commit_paging: 999 cmpl $0,_bdb_exists 1000 je bdb_commit_paging_exit 1001 1002 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 1003 movl $9,%ecx 1004reloc_gdt: 1005 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 1006 addl $8,%eax /* now KERNBASE>>24 */ 1007 loop reloc_gdt 1008 1009 subl $6,%esp 1010 sgdt (%esp) 1011 addl $KERNBASE,2(%esp) 1012 lgdt (%esp) 1013 sidt (%esp) 1014 addl $KERNBASE,2(%esp) 1015 lidt (%esp) 1016 addl $6,%esp 1017 1018 int $3 1019 1020bdb_commit_paging_exit: 1021 ret 1022 1023#endif /* BDE_DEBUGGER */ 1024