locore.s revision 60303
150476Speter/*- 210058Swollman * Copyright (c) 1990 The Regents of the University of California. 3299293Sgjb * All rights reserved. 4299293Sgjb * 510058Swollman * This code is derived from software contributed to Berkeley by 6264400Simp * William Jolitz. 710058Swollman * 810058Swollman * 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 60303 2000-05-10 01:24:23Z obrien $ 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/* Tell the bios to warmboot next time */ 229 movw $0x1234,0x472 230#endif /* PC98 */ 231 232/* Set up a real frame in case the double return in newboot is executed. */ 233 pushl %ebp 234 movl %esp, %ebp 235 236/* Don't trust what the BIOS gives for eflags. */ 237 pushl $PSL_KERNEL 238 popfl 239 240/* 241 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 242 * to set %cs, %ds, %es and %ss. 243 */ 244 mov %ds, %ax 245 mov %ax, %fs 246 mov %ax, %gs 247 248 call recover_bootinfo 249 250/* Get onto a stack that we can trust. */ 251/* 252 * XXX this step is delayed in case recover_bootinfo needs to return via 253 * the old stack, but it need not be, since recover_bootinfo actually 254 * returns via the old frame. 255 */ 256 movl $R(HIDENAME(tmpstk)),%esp 257 258#ifdef PC98 259 /* pc98_machine_type & M_EPSON_PC98 */ 260 testb $0x02,R(_pc98_system_parameter)+220 261 jz 3f 262 /* epson_machine_id <= 0x0b */ 263 cmpb $0x0b,R(_pc98_system_parameter)+224 264 ja 3f 265 266 /* count up memory */ 267 movl $0x100000,%eax /* next, talley remaining memory */ 268 movl $0xFFF-0x100,%ecx 2691: movl 0(%eax),%ebx /* save location to check */ 270 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 271 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 272 jne 2f 273 movl %ebx,0(%eax) /* restore memory */ 274 addl $PAGE_SIZE,%eax 275 loop 1b 2762: subl $0x100000,%eax 277 shrl $17,%eax 278 movb %al,R(_pc98_system_parameter)+1 2793: 280 281 movw R(_pc98_system_parameter+0x86),%ax 282 movw %ax,R(_cpu_id) 283#endif 284 285 call identify_cpu 286 287/* clear bss */ 288/* 289 * XXX this should be done a little earlier. 290 * 291 * XXX we don't check that there is memory for our bss and page tables 292 * before using it. 293 * 294 * XXX the boot program somewhat bogusly clears the bss. We still have 295 * to do it in case we were unzipped by kzipboot. Then the boot program 296 * only clears kzipboot's bss. 297 * 298 * XXX the gdt and idt are still somewhere in the boot program. We 299 * depend on the convention that the boot program is below 1MB and we 300 * are above 1MB to keep the gdt and idt away from the bss and page 301 * tables. The idt is only used if BDE_DEBUGGER is enabled. 302 */ 303 movl $R(_end),%ecx 304 movl $R(_edata),%edi 305 subl %edi,%ecx 306 xorl %eax,%eax 307 cld 308 rep 309 stosb 310 311 call create_pagetables 312 313/* 314 * If the CPU has support for VME, turn it on. 315 */ 316 testl $CPUID_VME, R(_cpu_feature) 317 jz 1f 318 movl %cr4, %eax 319 orl $CR4_VME, %eax 320 movl %eax, %cr4 3211: 322 323#ifdef BDE_DEBUGGER 324/* 325 * Adjust as much as possible for paging before enabling paging so that the 326 * adjustments can be traced. 327 */ 328 call bdb_prepare_paging 329#endif 330 331/* Now enable paging */ 332 movl R(_IdlePTD), %eax 333 movl %eax,%cr3 /* load ptd addr into mmu */ 334 movl %cr0,%eax /* get control word */ 335 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 336 movl %eax,%cr0 /* and let's page NOW! */ 337 338#ifdef BDE_DEBUGGER 339/* 340 * Complete the adjustments for paging so that we can keep tracing through 341 * initi386() after the low (physical) addresses for the gdt and idt become 342 * invalid. 343 */ 344 call bdb_commit_paging 345#endif 346 347 pushl $begin /* jump to high virtualized address */ 348 ret 349 350/* now running relocated at KERNBASE where the system is linked to run */ 351begin: 352 /* set up bootstrap stack */ 353 movl _proc0paddr,%esp /* location of in-kernel pages */ 354 addl $UPAGES*PAGE_SIZE,%esp /* bootstrap stack end location */ 355 xorl %eax,%eax /* mark end of frames */ 356 movl %eax,%ebp 357 movl _proc0paddr,%eax 358 movl _IdlePTD, %esi 359 movl %esi,PCB_CR3(%eax) 360 361 movl physfree, %esi 362 pushl %esi /* value of first for init386(first) */ 363 call _init386 /* wire 386 chip for unix operation */ 364 popl %esi 365 366 .globl __ucodesel,__udatasel 367 368 pushl $0 /* unused */ 369 pushl __udatasel /* ss */ 370 pushl $0 /* esp - filled in by execve() */ 371 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 372 pushl __ucodesel /* cs */ 373 pushl $0 /* eip - filled in by execve() */ 374 subl $(13*4),%esp /* space for rest of registers */ 375 376 pushl %esp /* call main with frame pointer */ 377 call _mi_startup /* autoconfiguration, mountroot etc */ 378 379 hlt /* never returns to here */ 380 381/* 382 * When starting init, call this to configure the process for user 383 * mode. This will be inherited by other processes. 384 */ 385NON_GPROF_ENTRY(prepare_usermode) 386 /* 387 * Now we've run main() and determined what cpu-type we are, we can 388 * enable write protection and alignment checking on i486 cpus and 389 * above. 390 */ 391#if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU) 392 cmpl $CPUCLASS_386,_cpu_class 393 je 1f 394 movl %cr0,%eax /* get control word */ 395 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 396 movl %eax,%cr0 /* and do it */ 3971: 398#endif 399 /* 400 * on return from main(), we are process 1 401 * set up address space and stack so that we can 'return' to user mode 402 */ 403 movl __ucodesel,%eax 404 movl __udatasel,%ecx 405 406#if 0 /* ds/es/fs are in trap frame */ 407 mov %cx,%ds 408 mov %cx,%es 409 mov %cx,%fs 410#endif 411 mov %cx,%gs /* and ds to gs */ 412 ret /* goto user! */ 413 414 415/* 416 * Signal trampoline, copied to top of user stack 417 */ 418NON_GPROF_ENTRY(sigcode) 419 call *SIGF_HANDLER(%esp) /* call signal handler */ 420 lea SIGF_UC(%esp),%eax /* get ucontext_t */ 421 pushl %eax 422 testl $PSL_VM,UC_EFLAGS(%eax) 423 jne 9f 424 movl UC_GS(%eax),%gs /* restore %gs */ 4259: 426 movl $SYS_sigreturn,%eax 427 pushl %eax /* junk to fake return addr. */ 428 int $0x80 /* enter kernel with args */ 4290: jmp 0b 430 431 ALIGN_TEXT 432_osigcode: 433 call *SIGF_HANDLER(%esp) /* call signal handler */ 434 lea SIGF_SC(%esp),%eax /* get sigcontext */ 435 pushl %eax 436 testl $PSL_VM,SC_PS(%eax) 437 jne 9f 438 movl SC_GS(%eax),%gs /* restore %gs */ 4399: 440 movl $0x01d516,SC_TRAPNO(%eax) /* magic: 0ldSiG */ 441 movl $SYS_sigreturn,%eax 442 pushl %eax /* junk to fake return addr. */ 443 int $0x80 /* enter kernel with args */ 4440: jmp 0b 445 446 ALIGN_TEXT 447_esigcode: 448 449 .data 450 .globl _szsigcode, _szosigcode 451_szsigcode: 452 .long _esigcode-_sigcode 453_szosigcode: 454 .long _esigcode-_osigcode 455 .text 456 457/********************************************************************** 458 * 459 * Recover the bootinfo passed to us from the boot program 460 * 461 */ 462recover_bootinfo: 463 /* 464 * This code is called in different ways depending on what loaded 465 * and started the kernel. This is used to detect how we get the 466 * arguments from the other code and what we do with them. 467 * 468 * Old disk boot blocks: 469 * (*btext)(howto, bootdev, cyloffset, esym); 470 * [return address == 0, and can NOT be returned to] 471 * [cyloffset was not supported by the FreeBSD boot code 472 * and always passed in as 0] 473 * [esym is also known as total in the boot code, and 474 * was never properly supported by the FreeBSD boot code] 475 * 476 * Old diskless netboot code: 477 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 478 * [return address != 0, and can NOT be returned to] 479 * If we are being booted by this code it will NOT work, 480 * so we are just going to halt if we find this case. 481 * 482 * New uniform boot code: 483 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 484 * [return address != 0, and can be returned to] 485 * 486 * There may seem to be a lot of wasted arguments in here, but 487 * that is so the newer boot code can still load very old kernels 488 * and old boot code can load new kernels. 489 */ 490 491 /* 492 * The old style disk boot blocks fake a frame on the stack and 493 * did an lret to get here. The frame on the stack has a return 494 * address of 0. 495 */ 496 cmpl $0,4(%ebp) 497 je olddiskboot 498 499 /* 500 * We have some form of return address, so this is either the 501 * old diskless netboot code, or the new uniform code. That can 502 * be detected by looking at the 5th argument, if it is 0 503 * we are being booted by the new uniform boot code. 504 */ 505 cmpl $0,24(%ebp) 506 je newboot 507 508 /* 509 * Seems we have been loaded by the old diskless boot code, we 510 * don't stand a chance of running as the diskless structure 511 * changed considerably between the two, so just halt. 512 */ 513 hlt 514 515 /* 516 * We have been loaded by the new uniform boot code. 517 * Let's check the bootinfo version, and if we do not understand 518 * it we return to the loader with a status of 1 to indicate this error 519 */ 520newboot: 521 movl 28(%ebp),%ebx /* &bootinfo.version */ 522 movl BI_VERSION(%ebx),%eax 523 cmpl $1,%eax /* We only understand version 1 */ 524 je 1f 525 movl $1,%eax /* Return status */ 526 leave 527 /* 528 * XXX this returns to our caller's caller (as is required) since 529 * we didn't set up a frame and our caller did. 530 */ 531 ret 532 5331: 534 /* 535 * If we have a kernelname copy it in 536 */ 537 movl BI_KERNELNAME(%ebx),%esi 538 cmpl $0,%esi 539 je 2f /* No kernelname */ 540 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 541 movl $R(_kernelname),%edi 542 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 543 je 1f 544 movb $'/',(%edi) 545 incl %edi 546 decl %ecx 5471: 548 cld 549 rep 550 movsb 551 5522: 553 /* 554 * Determine the size of the boot loader's copy of the bootinfo 555 * struct. This is impossible to do properly because old versions 556 * of the struct don't contain a size field and there are 2 old 557 * versions with the same version number. 558 */ 559 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 560 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 561 je got_bi_size /* no, sizeless version */ 562 movl BI_SIZE(%ebx),%ecx 563got_bi_size: 564 565 /* 566 * Copy the common part of the bootinfo struct 567 */ 568 movl %ebx,%esi 569 movl $R(_bootinfo),%edi 570 cmpl $BOOTINFO_SIZE,%ecx 571 jbe got_common_bi_size 572 movl $BOOTINFO_SIZE,%ecx 573got_common_bi_size: 574 cld 575 rep 576 movsb 577 578#ifdef NFS_ROOT 579#ifndef BOOTP_NFSV3 580 /* 581 * If we have a nfs_diskless structure copy it in 582 */ 583 movl BI_NFS_DISKLESS(%ebx),%esi 584 cmpl $0,%esi 585 je olddiskboot 586 movl $R(_nfs_diskless),%edi 587 movl $NFSDISKLESS_SIZE,%ecx 588 cld 589 rep 590 movsb 591 movl $R(_nfs_diskless_valid),%edi 592 movl $1,(%edi) 593#endif 594#endif 595 596 /* 597 * The old style disk boot. 598 * (*btext)(howto, bootdev, cyloffset, esym); 599 * Note that the newer boot code just falls into here to pick 600 * up howto and bootdev, cyloffset and esym are no longer used 601 */ 602olddiskboot: 603 movl 8(%ebp),%eax 604 movl %eax,R(_boothowto) 605 movl 12(%ebp),%eax 606 movl %eax,R(_bootdev) 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 if 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/* If we are told where the end of the kernel space is, believe it. */ 769 movl R(_bootinfo+BI_KERNEND),%edi 770 testl %edi,%edi 771 je no_kernend 772 movl %edi,%esi 773no_kernend: 774 775 addl $PAGE_MASK,%esi 776 andl $~PAGE_MASK,%esi 777 movl %esi,R(_KERNend) /* save end of kernel */ 778 movl %esi,R(physfree) /* next free page is at end of kernel */ 779 780/* Allocate Kernel Page Tables */ 781 ALLOCPAGES(NKPT) 782 movl %esi,R(_KPTphys) 783 784/* Allocate Page Table Directory */ 785 ALLOCPAGES(1) 786 movl %esi,R(_IdlePTD) 787 788/* Allocate UPAGES */ 789 ALLOCPAGES(UPAGES) 790 movl %esi,R(p0upa) 791 addl $KERNBASE, %esi 792 movl %esi, R(_proc0paddr) 793 794 ALLOCPAGES(1) /* vm86/bios stack */ 795 movl %esi,R(vm86phystk) 796 797 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 798 movl %esi,R(_vm86pa) 799 addl $KERNBASE, %esi 800 movl %esi, R(_vm86paddr) 801 802#ifdef SMP 803/* Allocate cpu0's private data page */ 804 ALLOCPAGES(1) 805 movl %esi,R(cpu0pp) 806 addl $KERNBASE, %esi 807 movl %esi, R(_cpu0prvpage) /* relocated to KVM space */ 808 809/* Allocate SMP page table page */ 810 ALLOCPAGES(1) 811 movl %esi,R(SMPptpa) 812 addl $KERNBASE, %esi 813 movl %esi, R(_SMPpt) /* relocated to KVM space */ 814#endif /* SMP */ 815 816/* Map read-only from zero to the end of the kernel text section */ 817 xorl %eax, %eax 818#ifdef BDE_DEBUGGER 819/* If the debugger is present, actually map everything read-write. */ 820 cmpl $0,R(_bdb_exists) 821 jne map_read_write 822#endif 823 xorl %edx,%edx 824 825#if !defined(SMP) 826 testl $CPUID_PGE, R(_cpu_feature) 827 jz 2f 828 orl $PG_G,%edx 829#endif 830 8312: movl $R(_etext),%ecx 832 addl $PAGE_MASK,%ecx 833 shrl $PAGE_SHIFT,%ecx 834 fillkptphys(%edx) 835 836/* Map read-write, data, bss and symbols */ 837 movl $R(_etext),%eax 838 addl $PAGE_MASK, %eax 839 andl $~PAGE_MASK, %eax 840map_read_write: 841 movl $PG_RW,%edx 842#if !defined(SMP) 843 testl $CPUID_PGE, R(_cpu_feature) 844 jz 1f 845 orl $PG_G,%edx 846#endif 847 8481: movl R(_KERNend),%ecx 849 subl %eax,%ecx 850 shrl $PAGE_SHIFT,%ecx 851 fillkptphys(%edx) 852 853/* Map page directory. */ 854 movl R(_IdlePTD), %eax 855 movl $1, %ecx 856 fillkptphys($PG_RW) 857 858/* Map proc0's UPAGES in the physical way ... */ 859 movl R(p0upa), %eax 860 movl $UPAGES, %ecx 861 fillkptphys($PG_RW) 862 863/* Map ISA hole */ 864 movl $ISA_HOLE_START, %eax 865 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 866 fillkptphys($PG_RW) 867 868/* Map space for the vm86 region */ 869 movl R(vm86phystk), %eax 870 movl $4, %ecx 871 fillkptphys($PG_RW) 872 873/* Map page 0 into the vm86 page table */ 874 movl $0, %eax 875 movl $0, %ebx 876 movl $1, %ecx 877 fillkpt(R(_vm86pa), $PG_RW|PG_U) 878 879/* ...likewise for the ISA hole */ 880 movl $ISA_HOLE_START, %eax 881 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 882 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 883 fillkpt(R(_vm86pa), $PG_RW|PG_U) 884 885#ifdef SMP 886/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 887 movl R(cpu0pp), %eax 888 movl $1, %ecx 889 fillkptphys($PG_RW) 890 891/* Map SMP page table page into global kmem FWIW */ 892 movl R(SMPptpa), %eax 893 movl $1, %ecx 894 fillkptphys($PG_RW) 895 896/* Map the private page into the SMP page table */ 897 movl R(cpu0pp), %eax 898 movl $0, %ebx /* pte offset = 0 */ 899 movl $1, %ecx /* one private page coming right up */ 900 fillkpt(R(SMPptpa), $PG_RW) 901 902/* ... and put the page table table in the pde. */ 903 movl R(SMPptpa), %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 $(NPTEPG-1), %ebx /* pte offset = NTEPG-1 */ 912 movl $1, %ecx /* one private pt coming right up */ 913 fillkpt(R(SMPptpa), $PG_RW) 914 915/* Initialize mp lock to allow early traps */ 916 movl $1, R(_mp_lock) 917#endif /* SMP */ 918 919/* install a pde for temporary double map of bottom of VA */ 920 movl R(_KPTphys), %eax 921 xorl %ebx, %ebx 922 movl $1, %ecx 923 fillkpt(R(_IdlePTD), $PG_RW) 924 925/* install pde's for pt's */ 926 movl R(_KPTphys), %eax 927 movl $KPTDI, %ebx 928 movl $NKPT, %ecx 929 fillkpt(R(_IdlePTD), $PG_RW) 930 931/* install a pde recursively mapping page directory as a page table */ 932 movl R(_IdlePTD), %eax 933 movl $PTDPTDI, %ebx 934 movl $1,%ecx 935 fillkpt(R(_IdlePTD), $PG_RW) 936 937 ret 938 939#ifdef BDE_DEBUGGER 940bdb_prepare_paging: 941 cmpl $0,R(_bdb_exists) 942 je bdb_prepare_paging_exit 943 944 subl $6,%esp 945 946 /* 947 * Copy and convert debugger entries from the bootstrap gdt and idt 948 * to the kernel gdt and idt. Everything is still in low memory. 949 * Tracing continues to work after paging is enabled because the 950 * low memory addresses remain valid until everything is relocated. 951 * However, tracing through the setidt() that initializes the trace 952 * trap will crash. 953 */ 954 sgdt (%esp) 955 movl 2(%esp),%esi /* base address of bootstrap gdt */ 956 movl $R(_gdt),%edi 957 movl %edi,2(%esp) /* prepare to load kernel gdt */ 958 movl $8*18/4,%ecx 959 cld 960 rep /* copy gdt */ 961 movsl 962 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 963 movb $0x92,-8+5(%edi) 964 lgdt (%esp) 965 966 sidt (%esp) 967 movl 2(%esp),%esi /* base address of current idt */ 968 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 969 movw 8(%esi),%ax 970 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 971 movl 8+2(%esi),%eax 972 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 973 movl 24+4(%esi),%eax /* same for bpt descriptor */ 974 movw 24(%esi),%ax 975 movl %eax,R(bdb_bpt_ljmp+1) 976 movl 24+2(%esi),%eax 977 movw %ax,R(bdb_bpt_ljmp+5) 978 movl R(_idt),%edi 979 movl %edi,2(%esp) /* prepare to load kernel idt */ 980 movl $8*4/4,%ecx 981 cld 982 rep /* copy idt */ 983 movsl 984 lidt (%esp) 985 986 addl $6,%esp 987 988bdb_prepare_paging_exit: 989 ret 990 991/* Relocate debugger gdt entries and gdt and idt pointers. */ 992bdb_commit_paging: 993 cmpl $0,_bdb_exists 994 je bdb_commit_paging_exit 995 996 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 997 movl $9,%ecx 998reloc_gdt: 999 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 1000 addl $8,%eax /* now KERNBASE>>24 */ 1001 loop reloc_gdt 1002 1003 subl $6,%esp 1004 sgdt (%esp) 1005 addl $KERNBASE,2(%esp) 1006 lgdt (%esp) 1007 sidt (%esp) 1008 addl $KERNBASE,2(%esp) 1009 lidt (%esp) 1010 addl $6,%esp 1011 1012 int $3 1013 1014bdb_commit_paging_exit: 1015 ret 1016 1017#endif /* BDE_DEBUGGER */ 1018