Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/i386/i386/locore.s
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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: releng/5.0/sys/i386/i386/locore.s 107521 2002-12-02 19:58:55Z deischen $ 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_compat.h" 48 #include "opt_nfsroot.h" 49 50 #include <sys/syscall.h> 51 #include <sys/reboot.h> 52 53 #include <machine/asmacros.h> 54 #include <machine/cputypes.h> 55 #include <machine/psl.h> 56 #include <machine/pmap.h> 57 #include <machine/specialreg.h> 58 59 #include "assym.s" 60 61 /* 62 * XXX 63 * 64 * Note: This version greatly munged to avoid various assembler errors 65 * that may be fixed in newer versions of gas. Perhaps newer versions 66 * will have more pleasant appearance. 67 */ 68 69 /* 70 * PTmap is recursive pagemap at top of virtual address space. 71 * Within PTmap, the page directory can be found (third indirection). 72 * 73 * NOTE: PTDpde, PTmap, and PTD are being defined as address symbols. 74 * In C you access them directly, and not with a '*'. Storage is not being 75 * allocated. They will magically address the correct locations in KVM 76 * which C will treat as normal variables of the type they are defined in 77 * machine/pmap.h, i.e. PTDpde = XX ; to set a PDE entry, NOT *PTDpde = XX; 78 */ 79 .globl PTmap,PTD,PTDpde 80 .set PTmap,(PTDPTDI << PDRSHIFT) 81 .set PTD,PTmap + (PTDPTDI * PAGE_SIZE) 82 .set PTDpde,PTD + (PTDPTDI * PDESIZE) 83 84 /* 85 * APTmap, APTD is the alternate recursive pagemap. 86 * It's used when modifying another process's page tables. 87 * See the note above. It is true here as well. 88 */ 89 .globl APTmap,APTD,APTDpde 90 .set APTmap,APTDPTDI << PDRSHIFT 91 .set APTD,APTmap + (APTDPTDI * PAGE_SIZE) 92 .set APTDpde,PTD + (APTDPTDI * PDESIZE) 93 94 #ifdef SMP 95 /* 96 * Define layout of per-cpu address space. 97 * This is "constructed" in locore.s on the BSP and in mp_machdep.c 98 * for each AP. DO NOT REORDER THESE WITHOUT UPDATING THE REST! 99 */ 100 .globl SMP_prvspace, lapic 101 .set SMP_prvspace,(MPPTDI << PDRSHIFT) 102 .set lapic,SMP_prvspace + (NPTEPG-1) * PAGE_SIZE 103 #endif /* SMP */ 104 105 /* 106 * Compiled KERNBASE location 107 */ 108 .globl kernbase 109 .set kernbase,KERNBASE 110 111 /* 112 * Globals 113 */ 114 .data 115 ALIGN_DATA /* just to be sure */ 116 117 .globl HIDENAME(tmpstk) 118 .space 0x2000 /* space for tmpstk - temporary stack */ 119 HIDENAME(tmpstk): 120 121 .globl bootinfo 122 bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 123 124 .globl KERNend 125 KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 126 physfree: .long 0 /* phys addr of next free page */ 127 128 #ifdef SMP 129 .globl cpu0prvpage 130 cpu0pp: .long 0 /* phys addr cpu0 private pg */ 131 cpu0prvpage: .long 0 /* relocated version */ 132 133 .globl SMPpt 134 SMPptpa: .long 0 /* phys addr SMP page table */ 135 SMPpt: .long 0 /* relocated version */ 136 #endif /* SMP */ 137 138 .globl IdlePTD 139 IdlePTD: .long 0 /* phys addr of kernel PTD */ 140 141 #ifdef SMP 142 .globl KPTphys 143 #endif 144 KPTphys: .long 0 /* phys addr of kernel page tables */ 145 146 .globl proc0uarea, proc0kstack 147 proc0uarea: .long 0 /* address of proc 0 uarea space */ 148 proc0kstack: .long 0 /* address of proc 0 kstack space */ 149 p0upa: .long 0 /* phys addr of proc0's UAREA */ 150 p0kpa: .long 0 /* phys addr of proc0's STACK */ 151 152 vm86phystk: .long 0 /* PA of vm86/bios stack */ 153 154 .globl vm86paddr, vm86pa 155 vm86paddr: .long 0 /* address of vm86 region */ 156 vm86pa: .long 0 /* phys addr of vm86 region */ 157 158 #ifdef BDE_DEBUGGER 159 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 160 _bdb_exists: .long 0 161 #endif 162 163 #ifdef PC98 164 .globl pc98_system_parameter 165 pc98_system_parameter: 166 .space 0x240 167 #endif 168 169 /********************************************************************** 170 * 171 * Some handy macros 172 * 173 */ 174 175 #define R(foo) ((foo)-KERNBASE) 176 177 #define ALLOCPAGES(foo) \ 178 movl R(physfree), %esi ; \ 179 movl $((foo)*PAGE_SIZE), %eax ; \ 180 addl %esi, %eax ; \ 181 movl %eax, R(physfree) ; \ 182 movl %esi, %edi ; \ 183 movl $((foo)*PAGE_SIZE),%ecx ; \ 184 xorl %eax,%eax ; \ 185 cld ; \ 186 rep ; \ 187 stosb 188 189 /* 190 * fillkpt 191 * eax = page frame address 192 * ebx = index into page table 193 * ecx = how many pages to map 194 * base = base address of page dir/table 195 * prot = protection bits 196 */ 197 #define fillkpt(base, prot) \ 198 shll $2,%ebx ; \ 199 addl base,%ebx ; \ 200 orl $PG_V,%eax ; \ 201 orl prot,%eax ; \ 202 1: movl %eax,(%ebx) ; \ 203 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 204 addl $4,%ebx ; /* next pte */ \ 205 loop 1b 206 207 /* 208 * fillkptphys(prot) 209 * eax = physical address 210 * ecx = how many pages to map 211 * prot = protection bits 212 */ 213 #define fillkptphys(prot) \ 214 movl %eax, %ebx ; \ 215 shrl $PAGE_SHIFT, %ebx ; \ 216 fillkpt(R(KPTphys), prot) 217 218 .text 219 /********************************************************************** 220 * 221 * This is where the bootblocks start us, set the ball rolling... 222 * 223 */ 224 NON_GPROF_ENTRY(btext) 225 226 #ifdef PC98 227 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 228 movl $0xa1400,%esi 229 movl $R(pc98_system_parameter),%edi 230 movl $0x0240,%ecx 231 cld 232 rep 233 movsb 234 #else /* IBM-PC */ 235 #ifdef BDE_DEBUGGER 236 #ifdef BIOS_STEALS_3K 237 cmpl $0x0375c339,0x95504 238 #else 239 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 240 #endif 241 jne 1f 242 movb $1,R(_bdb_exists) 243 1: 244 #endif 245 /* Tell the bios to warmboot next time */ 246 movw $0x1234,0x472 247 #endif /* PC98 */ 248 249 /* Set up a real frame in case the double return in newboot is executed. */ 250 pushl %ebp 251 movl %esp, %ebp 252 253 /* Don't trust what the BIOS gives for eflags. */ 254 pushl $PSL_KERNEL 255 popfl 256 257 /* 258 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 259 * to set %cs, %ds, %es and %ss. 260 */ 261 mov %ds, %ax 262 mov %ax, %fs 263 mov %ax, %gs 264 265 call recover_bootinfo 266 267 /* Get onto a stack that we can trust. */ 268 /* 269 * XXX this step is delayed in case recover_bootinfo needs to return via 270 * the old stack, but it need not be, since recover_bootinfo actually 271 * returns via the old frame. 272 */ 273 movl $R(HIDENAME(tmpstk)),%esp 274 275 #ifdef PC98 276 /* pc98_machine_type & M_EPSON_PC98 */ 277 testb $0x02,R(pc98_system_parameter)+220 278 jz 3f 279 /* epson_machine_id <= 0x0b */ 280 cmpb $0x0b,R(pc98_system_parameter)+224 281 ja 3f 282 283 /* count up memory */ 284 movl $0x100000,%eax /* next, talley remaining memory */ 285 movl $0xFFF-0x100,%ecx 286 1: movl 0(%eax),%ebx /* save location to check */ 287 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 288 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 289 jne 2f 290 movl %ebx,0(%eax) /* restore memory */ 291 addl $PAGE_SIZE,%eax 292 loop 1b 293 2: subl $0x100000,%eax 294 shrl $17,%eax 295 movb %al,R(pc98_system_parameter)+1 296 3: 297 298 movw R(pc98_system_parameter+0x86),%ax 299 movw %ax,R(cpu_id) 300 #endif 301 302 call identify_cpu 303 304 /* clear bss */ 305 /* 306 * XXX this should be done a little earlier. 307 * 308 * XXX we don't check that there is memory for our bss and page tables 309 * before using it. 310 * 311 * XXX the boot program somewhat bogusly clears the bss. We still have 312 * to do it in case we were unzipped by kzipboot. Then the boot program 313 * only clears kzipboot's bss. 314 * 315 * XXX the gdt and idt are still somewhere in the boot program. We 316 * depend on the convention that the boot program is below 1MB and we 317 * are above 1MB to keep the gdt and idt away from the bss and page 318 * tables. The idt is only used if BDE_DEBUGGER is enabled. 319 */ 320 movl $R(end),%ecx 321 movl $R(edata),%edi 322 subl %edi,%ecx 323 xorl %eax,%eax 324 cld 325 rep 326 stosb 327 328 call create_pagetables 329 330 /* 331 * If the CPU has support for VME, turn it on. 332 */ 333 testl $CPUID_VME, R(cpu_feature) 334 jz 1f 335 movl %cr4, %eax 336 orl $CR4_VME, %eax 337 movl %eax, %cr4 338 1: 339 340 #ifdef BDE_DEBUGGER 341 /* 342 * Adjust as much as possible for paging before enabling paging so that the 343 * adjustments can be traced. 344 */ 345 call bdb_prepare_paging 346 #endif 347 348 /* Now enable paging */ 349 movl R(IdlePTD), %eax 350 movl %eax,%cr3 /* load ptd addr into mmu */ 351 movl %cr0,%eax /* get control word */ 352 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 353 movl %eax,%cr0 /* and let's page NOW! */ 354 355 #ifdef BDE_DEBUGGER 356 /* 357 * Complete the adjustments for paging so that we can keep tracing through 358 * initi386() after the low (physical) addresses for the gdt and idt become 359 * invalid. 360 */ 361 call bdb_commit_paging 362 #endif 363 364 pushl $begin /* jump to high virtualized address */ 365 ret 366 367 /* now running relocated at KERNBASE where the system is linked to run */ 368 begin: 369 /* set up bootstrap stack */ 370 movl proc0kstack,%eax /* location of in-kernel stack */ 371 /* bootstrap stack end location */ 372 leal (KSTACK_PAGES*PAGE_SIZE-PCB_SIZE)(%eax),%esp 373 374 xorl %ebp,%ebp /* mark end of frames */ 375 376 movl IdlePTD,%esi 377 movl %esi,(KSTACK_PAGES*PAGE_SIZE-PCB_SIZE+PCB_CR3)(%eax) 378 379 pushl physfree /* value of first for init386(first) */ 380 call init386 /* wire 386 chip for unix operation */ 381 382 /* 383 * Clean up the stack in a way that db_numargs() understands, so 384 * that backtraces in ddb don't underrun the stack. Traps for 385 * inaccessible memory are more fatal than usual this early. 386 */ 387 addl $4,%esp 388 389 call mi_startup /* autoconfiguration, mountroot etc */ 390 /* NOTREACHED */ 391 addl $0,%esp /* for db_numargs() again */ 392 393 /* 394 * Signal trampoline, copied to top of user stack 395 */ 396 NON_GPROF_ENTRY(sigcode) 397 calll *SIGF_HANDLER(%esp) 398 leal SIGF_UC(%esp),%eax /* get ucontext */ 399 pushl %eax 400 testl $PSL_VM,UC_EFLAGS(%eax) 401 jne 1f 402 movl UC_GS(%eax),%gs /* restore %gs */ 403 1: 404 movl $SYS_sigreturn,%eax 405 pushl %eax /* junk to fake return addr. */ 406 int $0x80 /* enter kernel with args */ 407 /* on stack */ 408 1: 409 jmp 1b 410 411 #ifdef COMPAT_FREEBSD4 412 ALIGN_TEXT 413 freebsd4_sigcode: 414 calll *SIGF_HANDLER(%esp) 415 leal SIGF_UC4(%esp),%eax /* get ucontext */ 416 pushl %eax 417 testl $PSL_VM,UC4_EFLAGS(%eax) 418 jne 1f 419 movl UC4_GS(%eax),%gs /* restore %gs */ 420 1: 421 movl $344,%eax /* 4.x SYS_sigreturn */ 422 pushl %eax /* junk to fake return addr. */ 423 int $0x80 /* enter kernel with args */ 424 /* on stack */ 425 1: 426 jmp 1b 427 #endif 428 429 #ifdef COMPAT_43 430 ALIGN_TEXT 431 osigcode: 432 call *SIGF_HANDLER(%esp) /* call signal handler */ 433 lea SIGF_SC(%esp),%eax /* get sigcontext */ 434 pushl %eax 435 testl $PSL_VM,SC_PS(%eax) 436 jne 9f 437 movl SC_GS(%eax),%gs /* restore %gs */ 438 9: 439 movl $103,%eax /* 3.x SYS_sigreturn */ 440 pushl %eax /* junk to fake return addr. */ 441 int $0x80 /* enter kernel with args */ 442 0: jmp 0b 443 #endif /* COMPAT_43 */ 444 445 ALIGN_TEXT 446 esigcode: 447 448 .data 449 .globl szsigcode 450 szsigcode: 451 .long esigcode-sigcode 452 #ifdef COMPAT_FREEBSD4 453 .globl szfreebsd4_sigcode 454 szfreebsd4_sigcode: 455 .long esigcode-freebsd4_sigcode 456 #endif 457 #ifdef COMPAT_43 458 .globl szosigcode 459 szosigcode: 460 .long esigcode-osigcode 461 #endif 462 .text 463 464 /********************************************************************** 465 * 466 * Recover the bootinfo passed to us from the boot program 467 * 468 */ 469 recover_bootinfo: 470 /* 471 * This code is called in different ways depending on what loaded 472 * and started the kernel. This is used to detect how we get the 473 * arguments from the other code and what we do with them. 474 * 475 * Old disk boot blocks: 476 * (*btext)(howto, bootdev, cyloffset, esym); 477 * [return address == 0, and can NOT be returned to] 478 * [cyloffset was not supported by the FreeBSD boot code 479 * and always passed in as 0] 480 * [esym is also known as total in the boot code, and 481 * was never properly supported by the FreeBSD boot code] 482 * 483 * Old diskless netboot code: 484 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 485 * [return address != 0, and can NOT be returned to] 486 * If we are being booted by this code it will NOT work, 487 * so we are just going to halt if we find this case. 488 * 489 * New uniform boot code: 490 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 491 * [return address != 0, and can be returned to] 492 * 493 * There may seem to be a lot of wasted arguments in here, but 494 * that is so the newer boot code can still load very old kernels 495 * and old boot code can load new kernels. 496 */ 497 498 /* 499 * The old style disk boot blocks fake a frame on the stack and 500 * did an lret to get here. The frame on the stack has a return 501 * address of 0. 502 */ 503 cmpl $0,4(%ebp) 504 je olddiskboot 505 506 /* 507 * We have some form of return address, so this is either the 508 * old diskless netboot code, or the new uniform code. That can 509 * be detected by looking at the 5th argument, if it is 0 510 * we are being booted by the new uniform boot code. 511 */ 512 cmpl $0,24(%ebp) 513 je newboot 514 515 /* 516 * Seems we have been loaded by the old diskless boot code, we 517 * don't stand a chance of running as the diskless structure 518 * changed considerably between the two, so just halt. 519 */ 520 hlt 521 522 /* 523 * We have been loaded by the new uniform boot code. 524 * Let's check the bootinfo version, and if we do not understand 525 * it we return to the loader with a status of 1 to indicate this error 526 */ 527 newboot: 528 movl 28(%ebp),%ebx /* &bootinfo.version */ 529 movl BI_VERSION(%ebx),%eax 530 cmpl $1,%eax /* We only understand version 1 */ 531 je 1f 532 movl $1,%eax /* Return status */ 533 leave 534 /* 535 * XXX this returns to our caller's caller (as is required) since 536 * we didn't set up a frame and our caller did. 537 */ 538 ret 539 540 1: 541 /* 542 * If we have a kernelname copy it in 543 */ 544 movl BI_KERNELNAME(%ebx),%esi 545 cmpl $0,%esi 546 je 2f /* No kernelname */ 547 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 548 movl $R(kernelname),%edi 549 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 550 je 1f 551 movb $'/',(%edi) 552 incl %edi 553 decl %ecx 554 1: 555 cld 556 rep 557 movsb 558 559 2: 560 /* 561 * Determine the size of the boot loader's copy of the bootinfo 562 * struct. This is impossible to do properly because old versions 563 * of the struct don't contain a size field and there are 2 old 564 * versions with the same version number. 565 */ 566 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 567 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 568 je got_bi_size /* no, sizeless version */ 569 movl BI_SIZE(%ebx),%ecx 570 got_bi_size: 571 572 /* 573 * Copy the common part of the bootinfo struct 574 */ 575 movl %ebx,%esi 576 movl $R(bootinfo),%edi 577 cmpl $BOOTINFO_SIZE,%ecx 578 jbe got_common_bi_size 579 movl $BOOTINFO_SIZE,%ecx 580 got_common_bi_size: 581 cld 582 rep 583 movsb 584 585 #ifdef NFS_ROOT 586 #ifndef BOOTP_NFSV3 587 /* 588 * If we have a nfs_diskless structure copy it in 589 */ 590 movl BI_NFS_DISKLESS(%ebx),%esi 591 cmpl $0,%esi 592 je olddiskboot 593 movl $R(nfs_diskless),%edi 594 movl $NFSDISKLESS_SIZE,%ecx 595 cld 596 rep 597 movsb 598 movl $R(nfs_diskless_valid),%edi 599 movl $1,(%edi) 600 #endif 601 #endif 602 603 /* 604 * The old style disk boot. 605 * (*btext)(howto, bootdev, cyloffset, esym); 606 * Note that the newer boot code just falls into here to pick 607 * up howto and bootdev, cyloffset and esym are no longer used 608 */ 609 olddiskboot: 610 movl 8(%ebp),%eax 611 movl %eax,R(boothowto) 612 movl 12(%ebp),%eax 613 movl %eax,R(bootdev) 614 615 ret 616 617 618 /********************************************************************** 619 * 620 * Identify the CPU and initialize anything special about it 621 * 622 */ 623 identify_cpu: 624 625 /* Try to toggle alignment check flag; does not exist on 386. */ 626 pushfl 627 popl %eax 628 movl %eax,%ecx 629 orl $PSL_AC,%eax 630 pushl %eax 631 popfl 632 pushfl 633 popl %eax 634 xorl %ecx,%eax 635 andl $PSL_AC,%eax 636 pushl %ecx 637 popfl 638 639 testl %eax,%eax 640 jnz try486 641 642 /* NexGen CPU does not have aligment check flag. */ 643 pushfl 644 movl $0x5555, %eax 645 xorl %edx, %edx 646 movl $2, %ecx 647 clc 648 divl %ecx 649 jz trynexgen 650 popfl 651 movl $CPU_386,R(cpu) 652 jmp 3f 653 654 trynexgen: 655 popfl 656 movl $CPU_NX586,R(cpu) 657 movl $0x4778654e,R(cpu_vendor) # store vendor string 658 movl $0x72446e65,R(cpu_vendor+4) 659 movl $0x6e657669,R(cpu_vendor+8) 660 movl $0,R(cpu_vendor+12) 661 jmp 3f 662 663 try486: /* Try to toggle identification flag; does not exist on early 486s. */ 664 pushfl 665 popl %eax 666 movl %eax,%ecx 667 xorl $PSL_ID,%eax 668 pushl %eax 669 popfl 670 pushfl 671 popl %eax 672 xorl %ecx,%eax 673 andl $PSL_ID,%eax 674 pushl %ecx 675 popfl 676 677 testl %eax,%eax 678 jnz trycpuid 679 movl $CPU_486,R(cpu) 680 681 /* 682 * Check Cyrix CPU 683 * Cyrix CPUs do not change the undefined flags following 684 * execution of the divide instruction which divides 5 by 2. 685 * 686 * Note: CPUID is enabled on M2, so it passes another way. 687 */ 688 pushfl 689 movl $0x5555, %eax 690 xorl %edx, %edx 691 movl $2, %ecx 692 clc 693 divl %ecx 694 jnc trycyrix 695 popfl 696 jmp 3f /* You may use Intel CPU. */ 697 698 trycyrix: 699 popfl 700 /* 701 * IBM Bluelighting CPU also doesn't change the undefined flags. 702 * Because IBM doesn't disclose the information for Bluelighting 703 * CPU, we couldn't distinguish it from Cyrix's (including IBM 704 * brand of Cyrix CPUs). 705 */ 706 movl $0x69727943,R(cpu_vendor) # store vendor string 707 movl $0x736e4978,R(cpu_vendor+4) 708 movl $0x64616574,R(cpu_vendor+8) 709 jmp 3f 710 711 trycpuid: /* Use the `cpuid' instruction. */ 712 xorl %eax,%eax 713 cpuid # cpuid 0 714 movl %eax,R(cpu_high) # highest capability 715 movl %ebx,R(cpu_vendor) # store vendor string 716 movl %edx,R(cpu_vendor+4) 717 movl %ecx,R(cpu_vendor+8) 718 movb $0,R(cpu_vendor+12) 719 720 movl $1,%eax 721 cpuid # cpuid 1 722 movl %eax,R(cpu_id) # store cpu_id 723 movl %edx,R(cpu_feature) # store cpu_feature 724 rorl $8,%eax # extract family type 725 andl $15,%eax 726 cmpl $5,%eax 727 jae 1f 728 729 /* less than Pentium; must be 486 */ 730 movl $CPU_486,R(cpu) 731 jmp 3f 732 1: 733 /* a Pentium? */ 734 cmpl $5,%eax 735 jne 2f 736 movl $CPU_586,R(cpu) 737 jmp 3f 738 2: 739 /* Greater than Pentium...call it a Pentium Pro */ 740 movl $CPU_686,R(cpu) 741 3: 742 ret 743 744 745 /********************************************************************** 746 * 747 * Create the first page directory and its page tables. 748 * 749 */ 750 751 create_pagetables: 752 753 /* Find end of kernel image (rounded up to a page boundary). */ 754 movl $R(_end),%esi 755 756 /* Include symbols, if any. */ 757 movl R(bootinfo+BI_ESYMTAB),%edi 758 testl %edi,%edi 759 je over_symalloc 760 movl %edi,%esi 761 movl $KERNBASE,%edi 762 addl %edi,R(bootinfo+BI_SYMTAB) 763 addl %edi,R(bootinfo+BI_ESYMTAB) 764 over_symalloc: 765 766 /* If we are told where the end of the kernel space is, believe it. */ 767 movl R(bootinfo+BI_KERNEND),%edi 768 testl %edi,%edi 769 je no_kernend 770 movl %edi,%esi 771 no_kernend: 772 773 addl $PAGE_MASK,%esi 774 andl $~PAGE_MASK,%esi 775 movl %esi,R(KERNend) /* save end of kernel */ 776 movl %esi,R(physfree) /* next free page is at end of kernel */ 777 778 /* Allocate Kernel Page Tables */ 779 ALLOCPAGES(NKPT) 780 movl %esi,R(KPTphys) 781 782 /* Allocate Page Table Directory */ 783 ALLOCPAGES(1) 784 movl %esi,R(IdlePTD) 785 786 /* Allocate UPAGES */ 787 ALLOCPAGES(UAREA_PAGES) 788 movl %esi,R(p0upa) 789 addl $KERNBASE, %esi 790 movl %esi, R(proc0uarea) 791 792 ALLOCPAGES(KSTACK_PAGES) 793 movl %esi,R(p0kpa) 794 addl $KERNBASE, %esi 795 movl %esi, R(proc0kstack) 796 797 ALLOCPAGES(1) /* vm86/bios stack */ 798 movl %esi,R(vm86phystk) 799 800 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 801 movl %esi,R(vm86pa) 802 addl $KERNBASE, %esi 803 movl %esi, R(vm86paddr) 804 805 #ifdef SMP 806 /* Allocate cpu0's private data page */ 807 ALLOCPAGES(1) 808 movl %esi,R(cpu0pp) 809 addl $KERNBASE, %esi 810 movl %esi, R(cpu0prvpage) /* relocated to KVM space */ 811 812 /* Allocate SMP page table page */ 813 ALLOCPAGES(1) 814 movl %esi,R(SMPptpa) 815 addl $KERNBASE, %esi 816 movl %esi, R(SMPpt) /* relocated to KVM space */ 817 #endif /* SMP */ 818 819 /* Map read-only from zero to the end of the kernel text section */ 820 xorl %eax, %eax 821 #ifdef BDE_DEBUGGER 822 /* If the debugger is present, actually map everything read-write. */ 823 cmpl $0,R(_bdb_exists) 824 jne map_read_write 825 #endif 826 xorl %edx,%edx 827 movl $R(etext),%ecx 828 addl $PAGE_MASK,%ecx 829 shrl $PAGE_SHIFT,%ecx 830 fillkptphys(%edx) 831 832 /* Map read-write, data, bss and symbols */ 833 movl $R(etext),%eax 834 addl $PAGE_MASK, %eax 835 andl $~PAGE_MASK, %eax 836 map_read_write: 837 movl $PG_RW,%edx 838 movl R(KERNend),%ecx 839 subl %eax,%ecx 840 shrl $PAGE_SHIFT,%ecx 841 fillkptphys(%edx) 842 843 /* Map page directory. */ 844 movl R(IdlePTD), %eax 845 movl $1, %ecx 846 fillkptphys($PG_RW) 847 848 /* Map proc0's UPAGES in the physical way ... */ 849 movl R(p0upa), %eax 850 movl $(UAREA_PAGES), %ecx 851 fillkptphys($PG_RW) 852 853 /* Map proc0's KSTACK in the physical way ... */ 854 movl R(p0kpa), %eax 855 movl $(KSTACK_PAGES), %ecx 856 fillkptphys($PG_RW) 857 858 /* Map ISA hole */ 859 movl $ISA_HOLE_START, %eax 860 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 861 fillkptphys($PG_RW) 862 863 /* Map space for the vm86 region */ 864 movl R(vm86phystk), %eax 865 movl $4, %ecx 866 fillkptphys($PG_RW) 867 868 /* Map page 0 into the vm86 page table */ 869 movl $0, %eax 870 movl $0, %ebx 871 movl $1, %ecx 872 fillkpt(R(vm86pa), $PG_RW|PG_U) 873 874 /* ...likewise for the ISA hole */ 875 movl $ISA_HOLE_START, %eax 876 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 877 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 878 fillkpt(R(vm86pa), $PG_RW|PG_U) 879 880 #ifdef SMP 881 /* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 882 movl R(cpu0pp), %eax 883 movl $1, %ecx 884 fillkptphys($PG_RW) 885 886 /* Map SMP page table page into global kmem FWIW */ 887 movl R(SMPptpa), %eax 888 movl $1, %ecx 889 fillkptphys($PG_RW) 890 891 /* Map the private page into the SMP page table */ 892 movl R(cpu0pp), %eax 893 movl $0, %ebx /* pte offset = 0 */ 894 movl $1, %ecx /* one private page coming right up */ 895 fillkpt(R(SMPptpa), $PG_RW) 896 897 /* ... and put the page table table in the pde. */ 898 movl R(SMPptpa), %eax 899 movl $MPPTDI, %ebx 900 movl $1, %ecx 901 fillkpt(R(IdlePTD), $PG_RW) 902 903 /* Fakeup VA for the local apic to allow early traps. */ 904 ALLOCPAGES(1) 905 movl %esi, %eax 906 movl $(NPTEPG-1), %ebx /* pte offset = NTEPG-1 */ 907 movl $1, %ecx /* one private pt coming right up */ 908 fillkpt(R(SMPptpa), $PG_RW) 909 #endif /* SMP */ 910 911 /* install a pde for temporary double map of bottom of VA */ 912 movl R(KPTphys), %eax 913 xorl %ebx, %ebx 914 movl $NKPT, %ecx 915 fillkpt(R(IdlePTD), $PG_RW) 916 917 /* install pde's for pt's */ 918 movl R(KPTphys), %eax 919 movl $KPTDI, %ebx 920 movl $NKPT, %ecx 921 fillkpt(R(IdlePTD), $PG_RW) 922 923 /* install a pde recursively mapping page directory as a page table */ 924 movl R(IdlePTD), %eax 925 movl $PTDPTDI, %ebx 926 movl $1,%ecx 927 fillkpt(R(IdlePTD), $PG_RW) 928 929 ret 930 931 #ifdef BDE_DEBUGGER 932 bdb_prepare_paging: 933 cmpl $0,R(_bdb_exists) 934 je bdb_prepare_paging_exit 935 936 subl $6,%esp 937 938 /* 939 * Copy and convert debugger entries from the bootstrap gdt and idt 940 * to the kernel gdt and idt. Everything is still in low memory. 941 * Tracing continues to work after paging is enabled because the 942 * low memory addresses remain valid until everything is relocated. 943 * However, tracing through the setidt() that initializes the trace 944 * trap will crash. 945 */ 946 sgdt (%esp) 947 movl 2(%esp),%esi /* base address of bootstrap gdt */ 948 movl $R(_gdt),%edi 949 movl %edi,2(%esp) /* prepare to load kernel gdt */ 950 movl $8*18/4,%ecx 951 cld 952 rep /* copy gdt */ 953 movsl 954 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 955 movb $0x92,-8+5(%edi) 956 lgdt (%esp) 957 958 sidt (%esp) 959 movl 2(%esp),%esi /* base address of current idt */ 960 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 961 movw 8(%esi),%ax 962 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 963 movl 8+2(%esi),%eax 964 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 965 movl 24+4(%esi),%eax /* same for bpt descriptor */ 966 movw 24(%esi),%ax 967 movl %eax,R(bdb_bpt_ljmp+1) 968 movl 24+2(%esi),%eax 969 movw %ax,R(bdb_bpt_ljmp+5) 970 movl R(_idt),%edi 971 movl %edi,2(%esp) /* prepare to load kernel idt */ 972 movl $8*4/4,%ecx 973 cld 974 rep /* copy idt */ 975 movsl 976 lidt (%esp) 977 978 addl $6,%esp 979 980 bdb_prepare_paging_exit: 981 ret 982 983 /* Relocate debugger gdt entries and gdt and idt pointers. */ 984 bdb_commit_paging: 985 cmpl $0,_bdb_exists 986 je bdb_commit_paging_exit 987 988 movl $gdt+8*9,%eax /* adjust slots 9-17 */ 989 movl $9,%ecx 990 reloc_gdt: 991 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 992 addl $8,%eax /* now KERNBASE>>24 */ 993 loop reloc_gdt 994 995 subl $6,%esp 996 sgdt (%esp) 997 addl $KERNBASE,2(%esp) 998 lgdt (%esp) 999 sidt (%esp) 1000 addl $KERNBASE,2(%esp) 1001 lidt (%esp) 1002 addl $6,%esp 1003 1004 int $3 1005 1006 bdb_commit_paging_exit: 1007 ret 1008 1009 #endif /* BDE_DEBUGGER */
Cache object: 2bae0d3a8c4c50fbf6275c9688752e17
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