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 * $FreeBSD$ 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_ddb.h" 49 #include "opt_nfsroot.h" 50 #include "opt_userconfig.h" 51 #include "opt_vm86.h" 52 53 #include <sys/syscall.h> 54 #include <sys/reboot.h> 55 56 #include <machine/asmacros.h> 57 #include <machine/cputypes.h> 58 #include <machine/psl.h> 59 #include <machine/pmap.h> 60 #include <machine/specialreg.h> 61 62 #include "assym.s" 63 64 /* 65 * XXX 66 * 67 * Note: This version greatly munged to avoid various assembler errors 68 * that may be fixed in newer versions of gas. Perhaps newer versions 69 * will have more pleasant appearance. 70 */ 71 72 /* 73 * PTmap is recursive pagemap at top of virtual address space. 74 * Within PTmap, the page directory can be found (third indirection). 75 */ 76 .globl _PTmap,_PTD,_PTDpde 77 .set _PTmap,(PTDPTDI << PDRSHIFT) 78 .set _PTD,_PTmap + (PTDPTDI * PAGE_SIZE) 79 .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 80 81 /* 82 * APTmap, APTD is the alternate recursive pagemap. 83 * It's used when modifying another process's page tables. 84 */ 85 .globl _APTmap,_APTD,_APTDpde 86 .set _APTmap,APTDPTDI << PDRSHIFT 87 .set _APTD,_APTmap + (APTDPTDI * PAGE_SIZE) 88 .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 89 90 /* 91 * Globals 92 */ 93 .data 94 ALIGN_DATA /* just to be sure */ 95 96 .globl tmpstk 97 .space 0x2000 /* space for tmpstk - temporary stack */ 98 tmpstk: 99 100 .globl _boothowto,_bootdev 101 102 .globl _cpu,_cpu_vendor,_cpu_id,_bootinfo 103 .globl _cpu_high, _cpu_feature 104 105 _cpu: .long 0 /* are we 386, 386sx, or 486 */ 106 _cpu_id: .long 0 /* stepping ID */ 107 _cpu_high: .long 0 /* highest arg to CPUID */ 108 _cpu_feature: .long 0 /* features */ 109 _cpu_vendor: .space 20 /* CPU origin code */ 110 _bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 111 112 _KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 113 physfree: .long 0 /* phys addr of next free page */ 114 115 #ifdef SMP 116 cpu0pp: .long 0 /* phys addr cpu0 private pg */ 117 cpu0pt: .long 0 /* phys addr cpu0 private pt */ 118 119 .globl _cpu0prvpage,_cpu0prvpt 120 _cpu0prvpage: .long 0 /* relocated version */ 121 _cpu0prvpt: .long 0 /* relocated version */ 122 #endif /* SMP */ 123 124 .globl _IdlePTD 125 _IdlePTD: .long 0 /* phys addr of kernel PTD */ 126 127 #ifdef SMP 128 .globl _KPTphys 129 #endif 130 _KPTphys: .long 0 /* phys addr of kernel page tables */ 131 132 .globl _proc0paddr 133 _proc0paddr: .long 0 /* address of proc 0 address space */ 134 p0upa: .long 0 /* phys addr of proc0's UPAGES */ 135 136 #ifdef VM86 137 vm86phystk: .long 0 /* PA of vm86/bios stack */ 138 139 .globl _vm86paddr, _vm86pa 140 _vm86paddr: .long 0 /* address of vm86 region */ 141 _vm86pa: .long 0 /* phys addr of vm86 region */ 142 #endif 143 144 #ifdef BDE_DEBUGGER 145 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 146 _bdb_exists: .long 0 147 #endif 148 149 #ifdef PC98 150 .globl _pc98_system_parameter 151 _pc98_system_parameter: 152 .space 0x240 153 #endif 154 155 /********************************************************************** 156 * 157 * Some handy macros 158 * 159 */ 160 161 #define R(foo) ((foo)-KERNBASE) 162 163 #define ALLOCPAGES(foo) \ 164 movl R(physfree), %esi ; \ 165 movl $((foo)*PAGE_SIZE), %eax ; \ 166 addl %esi, %eax ; \ 167 movl %eax, R(physfree) ; \ 168 movl %esi, %edi ; \ 169 movl $((foo)*PAGE_SIZE),%ecx ; \ 170 xorl %eax,%eax ; \ 171 cld ; \ 172 rep ; \ 173 stosb 174 175 /* 176 * fillkpt 177 * eax = page frame address 178 * ebx = index into page table 179 * ecx = how many pages to map 180 * base = base address of page dir/table 181 * prot = protection bits 182 */ 183 #define fillkpt(base, prot) \ 184 shll $2,%ebx ; \ 185 addl base,%ebx ; \ 186 orl $PG_V,%eax ; \ 187 orl prot,%eax ; \ 188 1: movl %eax,(%ebx) ; \ 189 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 190 addl $4,%ebx ; /* next pte */ \ 191 loop 1b 192 193 /* 194 * fillkptphys(prot) 195 * eax = physical address 196 * ecx = how many pages to map 197 * prot = protection bits 198 */ 199 #define fillkptphys(prot) \ 200 movl %eax, %ebx ; \ 201 shrl $PAGE_SHIFT, %ebx ; \ 202 fillkpt(R(_KPTphys), prot) 203 204 .text 205 /********************************************************************** 206 * 207 * This is where the bootblocks start us, set the ball rolling... 208 * 209 */ 210 NON_GPROF_ENTRY(btext) 211 212 #ifdef PC98 213 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 214 movl $0xa1400,%esi 215 movl $R(_pc98_system_parameter),%edi 216 movl $0x0240,%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) 229 1: 230 #endif 231 /* Tell the bios to warmboot next time */ 232 movw $0x1234,0x472 233 #endif /* PC98 */ 234 235 /* Set up a real frame in case the double return in newboot is executed. */ 236 pushl %ebp 237 movl %esp, %ebp 238 239 /* Don't trust what the BIOS gives for eflags. */ 240 pushl $PSL_KERNEL 241 popfl 242 243 /* 244 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 245 * to set %cs, %ds, %es and %ss. 246 */ 247 mov %ds, %ax 248 mov %ax, %fs 249 mov %ax, %gs 250 251 /* 252 * Clear the bss. Not all boot programs do it, and it is our job anyway. 253 * 254 * XXX we don't check that there is memory for our bss and page tables 255 * before using it. 256 * 257 * Note: we must be careful to not overwrite an active gdt or idt. In 258 * the !BDE_DEBUGGER case they are inactive from now until we switch to 259 * new ones, since we don't load any more segment registers or permit 260 * interrupts until after the switch. In the BDE_DEBUGGER case, we depend 261 * on the convention that the boot program is below 1MB and we are above 262 * 1MB to keep the gdt and idt away from the bss and page tables. 263 */ 264 movl $R(_end),%ecx 265 movl $R(_edata),%edi 266 subl %edi,%ecx 267 xorl %eax,%eax 268 cld 269 rep 270 stosb 271 272 call recover_bootinfo 273 274 /* Get onto a stack that we can trust. */ 275 /* 276 * XXX this step is delayed in case recover_bootinfo needs to return via 277 * the old stack, but it need not be, since recover_bootinfo actually 278 * returns via the old frame. 279 */ 280 movl $R(tmpstk),%esp 281 282 #ifdef PC98 283 /* pc98_machine_type & M_EPSON_PC98 */ 284 testb $0x02,R(_pc98_system_parameter)+220 285 jz 3f 286 /* epson_machine_id <= 0x0b */ 287 cmpb $0x0b,R(_pc98_system_parameter)+224 288 ja 3f 289 290 /* count up memory */ 291 movl $0x100000,%eax /* next, talley remaining memory */ 292 movl $0xFFF-0x100,%ecx 293 1: movl 0(%eax),%ebx /* save location to check */ 294 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 295 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 296 jne 2f 297 movl %ebx,0(%eax) /* restore memory */ 298 addl $PAGE_SIZE,%eax 299 loop 1b 300 2: subl $0x100000,%eax 301 shrl $17,%eax 302 movb %al,R(_pc98_system_parameter)+1 303 3: 304 305 movw R(_pc98_system_parameter+0x86),%ax 306 movw %ax,R(_cpu_id) 307 #endif 308 309 call identify_cpu 310 311 #if NAPM > 0 312 #ifndef VM86 313 /* 314 * XXX it's not clear that APM can live in the current environonment. 315 * Only pc-relative addressing works. 316 */ 317 call _apm_setup 318 #endif 319 #endif 320 321 call create_pagetables 322 323 #ifdef VM86 324 /* 325 * If the CPU has support for VME, turn it on. 326 */ 327 testl $CPUID_VME, R(_cpu_feature) 328 jz 1f 329 movl %cr4, %eax 330 orl $CR4_VME, %eax 331 movl %eax, %cr4 332 1: 333 #endif /* VM86 */ 334 335 #ifdef BDE_DEBUGGER 336 /* 337 * Adjust as much as possible for paging before enabling paging so that the 338 * adjustments can be traced. 339 */ 340 call bdb_prepare_paging 341 #endif 342 343 /* Now enable paging */ 344 movl R(_IdlePTD), %eax 345 movl %eax,%cr3 /* load ptd addr into mmu */ 346 movl %cr0,%eax /* get control word */ 347 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 348 movl %eax,%cr0 /* and let's page NOW! */ 349 350 #ifdef BDE_DEBUGGER 351 /* 352 * Complete the adjustments for paging so that we can keep tracing through 353 * initi386() after the low (physical) addresses for the gdt and idt become 354 * invalid. 355 */ 356 call bdb_commit_paging 357 #endif 358 359 pushl $begin /* jump to high virtualized address */ 360 ret 361 362 /* now running relocated at KERNBASE where the system is linked to run */ 363 begin: 364 /* set up bootstrap stack */ 365 movl _proc0paddr,%esp /* location of in-kernel pages */ 366 addl $UPAGES*PAGE_SIZE,%esp /* bootstrap stack end location */ 367 xorl %eax,%eax /* mark end of frames */ 368 movl %eax,%ebp 369 movl _proc0paddr,%eax 370 movl _IdlePTD, %esi 371 movl %esi,PCB_CR3(%eax) 372 movl $_proc0,_curproc 373 374 movl physfree, %esi 375 pushl %esi /* value of first for init386(first) */ 376 call _init386 /* wire 386 chip for unix operation */ 377 popl %esi 378 379 .globl __ucodesel,__udatasel 380 381 pushl $0 /* unused */ 382 pushl __udatasel /* ss */ 383 pushl $0 /* esp - filled in by execve() */ 384 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 385 pushl __ucodesel /* cs */ 386 pushl $0 /* eip - filled in by execve() */ 387 subl $(12*4),%esp /* space for rest of registers */ 388 389 pushl %esp /* call main with frame pointer */ 390 call _main /* autoconfiguration, mountroot etc */ 391 392 hlt /* never returns to here */ 393 394 /* 395 * When starting init, call this to configure the process for user 396 * mode. This will be inherited by other processes. 397 */ 398 NON_GPROF_ENTRY(prepare_usermode) 399 /* 400 * Now we've run main() and determined what cpu-type we are, we can 401 * enable write protection and alignment checking on i486 cpus and 402 * above. 403 */ 404 #if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU) 405 cmpl $CPUCLASS_386,_cpu_class 406 je 1f 407 movl %cr0,%eax /* get control word */ 408 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 409 movl %eax,%cr0 /* and do it */ 410 1: 411 #endif 412 /* 413 * on return from main(), we are process 1 414 * set up address space and stack so that we can 'return' to user mode 415 */ 416 movl __ucodesel,%eax 417 movl __udatasel,%ecx 418 419 #if 0 420 movl %cx,%ds 421 #endif 422 movl %cx,%es 423 movl %ax,%fs /* double map cs to fs */ 424 movl %cx,%gs /* and ds to gs */ 425 ret /* goto user! */ 426 427 428 #define LCALL(x,y) .byte 0x9a ; .long y ; .word x 429 430 /* 431 * Signal trampoline, copied to top of user stack 432 */ 433 NON_GPROF_ENTRY(sigcode) 434 call SIGF_HANDLER(%esp) 435 lea SIGF_SC(%esp),%eax /* scp (the copy at 8(%esp) */ 436 pushl %eax /* may have been clobbered) */ 437 testl $PSL_VM,SC_PS(%eax) 438 jne 9f 439 movl SC_FS(%eax),%fs /* restore %fs */ 440 movl SC_GS(%eax),%gs /* restore %gs */ 441 9: 442 pushl %eax /* junk to fake return addr */ 443 movl $SYS_sigreturn,%eax /* sigreturn() */ 444 LCALL(0x7,0) /* enter kernel with args */ 445 0: jmp 0b 446 ALIGN_TEXT 447 _esigcode: 448 449 .data 450 .globl _szsigcode 451 _szsigcode: 452 .long _esigcode-_sigcode 453 .text 454 455 /********************************************************************** 456 * 457 * Recover the bootinfo passed to us from the boot program 458 * 459 */ 460 recover_bootinfo: 461 /* 462 * This code is called in different ways depending on what loaded 463 * and started the kernel. This is used to detect how we get the 464 * arguments from the other code and what we do with them. 465 * 466 * Old disk boot blocks: 467 * (*btext)(howto, bootdev, cyloffset, esym); 468 * [return address == 0, and can NOT be returned to] 469 * [cyloffset was not supported by the FreeBSD boot code 470 * and always passed in as 0] 471 * [esym is also known as total in the boot code, and 472 * was never properly supported by the FreeBSD boot code] 473 * 474 * Old diskless netboot code: 475 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 476 * [return address != 0, and can NOT be returned to] 477 * If we are being booted by this code it will NOT work, 478 * so we are just going to halt if we find this case. 479 * 480 * New uniform boot code: 481 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 482 * [return address != 0, and can be returned to] 483 * 484 * There may seem to be a lot of wasted arguments in here, but 485 * that is so the newer boot code can still load very old kernels 486 * and old boot code can load new kernels. 487 */ 488 489 /* 490 * The old style disk boot blocks fake a frame on the stack and 491 * did an lret to get here. The frame on the stack has a return 492 * address of 0. 493 */ 494 cmpl $0,4(%ebp) 495 je olddiskboot 496 497 /* 498 * We have some form of return address, so this is either the 499 * old diskless netboot code, or the new uniform code. That can 500 * be detected by looking at the 5th argument, if it is 0 501 * we are being booted by the new uniform boot code. 502 */ 503 cmpl $0,24(%ebp) 504 je newboot 505 506 /* 507 * Seems we have been loaded by the old diskless boot code, we 508 * don't stand a chance of running as the diskless structure 509 * changed considerably between the two, so just halt. 510 */ 511 hlt 512 513 /* 514 * We have been loaded by the new uniform boot code. 515 * Let's check the bootinfo version, and if we do not understand 516 * it we return to the loader with a status of 1 to indicate this error 517 */ 518 newboot: 519 movl 28(%ebp),%ebx /* &bootinfo.version */ 520 movl BI_VERSION(%ebx),%eax 521 cmpl $1,%eax /* We only understand version 1 */ 522 je 1f 523 movl $1,%eax /* Return status */ 524 leave 525 /* 526 * XXX this returns to our caller's caller (as is required) since 527 * we didn't set up a frame and our caller did. 528 */ 529 ret 530 531 1: 532 /* 533 * If we have a kernelname copy it in 534 */ 535 movl BI_KERNELNAME(%ebx),%esi 536 cmpl $0,%esi 537 je 2f /* No kernelname */ 538 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 539 movl $R(_kernelname),%edi 540 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 541 je 1f 542 movb $'/',(%edi) 543 incl %edi 544 decl %ecx 545 1: 546 cld 547 rep 548 movsb 549 550 2: 551 /* 552 * Determine the size of the boot loader's copy of the bootinfo 553 * struct. This is impossible to do properly because old versions 554 * of the struct don't contain a size field and there are 2 old 555 * versions with the same version number. 556 */ 557 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 558 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 559 je got_bi_size /* no, sizeless version */ 560 movl BI_SIZE(%ebx),%ecx 561 got_bi_size: 562 563 /* 564 * Copy the common part of the bootinfo struct 565 */ 566 movl %ebx,%esi 567 movl $R(_bootinfo),%edi 568 cmpl $BOOTINFO_SIZE,%ecx 569 jbe got_common_bi_size 570 movl $BOOTINFO_SIZE,%ecx 571 got_common_bi_size: 572 cld 573 rep 574 movsb 575 576 #ifdef NFS_ROOT 577 #ifndef BOOTP_NFSV3 578 /* 579 * If we have a nfs_diskless structure copy it in 580 */ 581 movl BI_NFS_DISKLESS(%ebx),%esi 582 cmpl $0,%esi 583 je olddiskboot 584 movl $R(_nfs_diskless),%edi 585 movl $NFSDISKLESS_SIZE,%ecx 586 cld 587 rep 588 movsb 589 movl $R(_nfs_diskless_valid),%edi 590 movl $1,(%edi) 591 #endif 592 #endif 593 594 /* 595 * The old style disk boot. 596 * (*btext)(howto, bootdev, cyloffset, esym); 597 * Note that the newer boot code just falls into here to pick 598 * up howto and bootdev, cyloffset and esym are no longer used 599 */ 600 olddiskboot: 601 movl 8(%ebp),%eax 602 movl %eax,R(_boothowto) 603 movl 12(%ebp),%eax 604 movl %eax,R(_bootdev) 605 606 ret 607 608 609 /********************************************************************** 610 * 611 * Identify the CPU and initialize anything special about it 612 * 613 */ 614 identify_cpu: 615 616 /* Try to toggle alignment check flag; does not exist on 386. */ 617 pushfl 618 popl %eax 619 movl %eax,%ecx 620 orl $PSL_AC,%eax 621 pushl %eax 622 popfl 623 pushfl 624 popl %eax 625 xorl %ecx,%eax 626 andl $PSL_AC,%eax 627 pushl %ecx 628 popfl 629 630 testl %eax,%eax 631 jnz try486 632 633 /* NexGen CPU does not have aligment check flag. */ 634 pushfl 635 movl $0x5555, %eax 636 xorl %edx, %edx 637 movl $2, %ecx 638 clc 639 divl %ecx 640 jz trynexgen 641 popfl 642 movl $CPU_386,R(_cpu) 643 jmp 3f 644 645 trynexgen: 646 popfl 647 movl $CPU_NX586,R(_cpu) 648 movl $0x4778654e,R(_cpu_vendor) # store vendor string 649 movl $0x72446e65,R(_cpu_vendor+4) 650 movl $0x6e657669,R(_cpu_vendor+8) 651 movl $0,R(_cpu_vendor+12) 652 jmp 3f 653 654 try486: /* Try to toggle identification flag; does not exist on early 486s. */ 655 pushfl 656 popl %eax 657 movl %eax,%ecx 658 xorl $PSL_ID,%eax 659 pushl %eax 660 popfl 661 pushfl 662 popl %eax 663 xorl %ecx,%eax 664 andl $PSL_ID,%eax 665 pushl %ecx 666 popfl 667 668 testl %eax,%eax 669 jnz trycpuid 670 movl $CPU_486,R(_cpu) 671 672 /* 673 * Check Cyrix CPU 674 * Cyrix CPUs do not change the undefined flags following 675 * execution of the divide instruction which divides 5 by 2. 676 * 677 * Note: CPUID is enabled on M2, so it passes another way. 678 */ 679 pushfl 680 movl $0x5555, %eax 681 xorl %edx, %edx 682 movl $2, %ecx 683 clc 684 divl %ecx 685 jnc trycyrix 686 popfl 687 jmp 3f /* You may use Intel CPU. */ 688 689 trycyrix: 690 popfl 691 /* 692 * IBM Bluelighting CPU also doesn't change the undefined flags. 693 * Because IBM doesn't disclose the information for Bluelighting 694 * CPU, we couldn't distinguish it from Cyrix's (including IBM 695 * brand of Cyrix CPUs). 696 */ 697 movl $0x69727943,R(_cpu_vendor) # store vendor string 698 movl $0x736e4978,R(_cpu_vendor+4) 699 movl $0x64616574,R(_cpu_vendor+8) 700 jmp 3f 701 702 trycpuid: /* Use the `cpuid' instruction. */ 703 xorl %eax,%eax 704 .byte 0x0f,0xa2 # cpuid 0 705 movl %eax,R(_cpu_high) # highest capability 706 movl %ebx,R(_cpu_vendor) # store vendor string 707 movl %edx,R(_cpu_vendor+4) 708 movl %ecx,R(_cpu_vendor+8) 709 movb $0,R(_cpu_vendor+12) 710 711 movl $1,%eax 712 .byte 0x0f,0xa2 # cpuid 1 713 movl %eax,R(_cpu_id) # store cpu_id 714 movl %edx,R(_cpu_feature) # store cpu_feature 715 rorl $8,%eax # extract family type 716 andl $15,%eax 717 cmpl $5,%eax 718 jae 1f 719 720 /* less than Pentium; must be 486 */ 721 movl $CPU_486,R(_cpu) 722 jmp 3f 723 1: 724 /* a Pentium? */ 725 cmpl $5,%eax 726 jne 2f 727 movl $CPU_586,R(_cpu) 728 jmp 3f 729 2: 730 /* Greater than Pentium...call it a Pentium Pro */ 731 movl $CPU_686,R(_cpu) 732 3: 733 ret 734 735 736 /********************************************************************** 737 * 738 * Create the first page directory and its page tables. 739 * 740 */ 741 742 create_pagetables: 743 744 testl $CPUID_PGE, R(_cpu_feature) 745 jz 1f 746 movl %cr4, %eax 747 orl $CR4_PGE, %eax 748 movl %eax, %cr4 749 1: 750 751 /* Find end of kernel image (rounded up to a page boundary). */ 752 movl $R(_end),%esi 753 754 /* include symbols if loaded and useful */ 755 #ifdef DDB 756 movl R(_bootinfo+BI_ESYMTAB),%edi 757 testl %edi,%edi 758 je over_symalloc 759 movl %edi,%esi 760 movl $KERNBASE,%edi 761 addl %edi,R(_bootinfo+BI_SYMTAB) 762 addl %edi,R(_bootinfo+BI_ESYMTAB) 763 over_symalloc: 764 #endif 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(UPAGES) 788 movl %esi,R(p0upa) 789 addl $KERNBASE, %esi 790 movl %esi, R(_proc0paddr) 791 792 #ifdef VM86 793 ALLOCPAGES(1) /* vm86/bios stack */ 794 movl %esi,R(vm86phystk) 795 796 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 797 movl %esi,R(_vm86pa) 798 addl $KERNBASE, %esi 799 movl %esi, R(_vm86paddr) 800 #endif /* VM86 */ 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 cpu0's private page table for mapping priv page, apic, etc */ 810 ALLOCPAGES(1) 811 movl %esi,R(cpu0pt) 812 addl $KERNBASE, %esi 813 movl %esi, R(_cpu0prvpt) /* 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 830 831 2: 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 840 map_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 847 848 1: 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 #ifdef VM86 869 /* Map space for the vm86 region */ 870 movl R(vm86phystk), %eax 871 movl $4, %ecx 872 fillkptphys($PG_RW) 873 874 /* Map page 0 into the vm86 page table */ 875 movl $0, %eax 876 movl $0, %ebx 877 movl $1, %ecx 878 fillkpt(R(_vm86pa), $PG_RW|PG_U) 879 880 /* ...likewise for the ISA hole */ 881 movl $ISA_HOLE_START, %eax 882 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 883 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 884 fillkpt(R(_vm86pa), $PG_RW|PG_U) 885 #endif /* VM86 */ 886 887 #ifdef SMP 888 /* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 889 movl R(cpu0pp), %eax 890 movl $1, %ecx 891 fillkptphys($PG_RW) 892 893 /* Map cpu0's private page table into global kmem FWIW */ 894 movl R(cpu0pt), %eax 895 movl $1, %ecx 896 fillkptphys($PG_RW) 897 898 /* Map the private page into the private page table into private space */ 899 movl R(cpu0pp), %eax 900 movl $0, %ebx /* pte offset = 0 */ 901 movl $1, %ecx /* one private page coming right up */ 902 fillkpt(R(cpu0pt), $PG_RW) 903 904 /* Map the page table page into private space */ 905 movl R(cpu0pt), %eax 906 movl $1, %ebx /* pte offset = 1 */ 907 movl $1, %ecx /* one private pt coming right up */ 908 fillkpt(R(cpu0pt), $PG_RW) 909 910 /* ... and put the page table table in the pde. */ 911 movl R(cpu0pt), %eax 912 movl $MPPTDI, %ebx 913 movl $1, %ecx 914 fillkpt(R(_IdlePTD), $PG_RW) 915 916 /* Fakeup VA for the local apic to allow early traps. */ 917 ALLOCPAGES(1) 918 movl %esi, %eax 919 movl $2, %ebx /* pte offset = 2 */ 920 movl $1, %ecx /* one private pt coming right up */ 921 fillkpt(R(cpu0pt), $PG_RW) 922 923 /* Initialize mp lock to allow early traps */ 924 movl $1, R(_mp_lock) 925 926 /* Initialize my_idlePTD to IdlePTD */ 927 movl R(cpu0pp), %eax 928 movl R(_IdlePTD), %ecx 929 movl %ecx,GD_MY_IDLEPTD(%eax) 930 /* Initialize IdlePTDS[0] */ 931 addl $KERNBASE, %ecx 932 movl %ecx, R(CNAME(IdlePTDS)) 933 934 #endif /* SMP */ 935 936 /* install a pde for temporary double map of bottom of VA */ 937 movl R(_KPTphys), %eax 938 xorl %ebx, %ebx 939 movl $1, %ecx 940 fillkpt(R(_IdlePTD), $PG_RW) 941 942 /* install pde's for pt's */ 943 movl R(_KPTphys), %eax 944 movl $KPTDI, %ebx 945 movl $NKPT, %ecx 946 fillkpt(R(_IdlePTD), $PG_RW) 947 948 /* install a pde recursively mapping page directory as a page table */ 949 movl R(_IdlePTD), %eax 950 movl $PTDPTDI, %ebx 951 movl $1,%ecx 952 fillkpt(R(_IdlePTD), $PG_RW) 953 954 ret 955 956 #ifdef BDE_DEBUGGER 957 bdb_prepare_paging: 958 cmpl $0,R(_bdb_exists) 959 je bdb_prepare_paging_exit 960 961 subl $6,%esp 962 963 /* 964 * Copy and convert debugger entries from the bootstrap gdt and idt 965 * to the kernel gdt and idt. Everything is still in low memory. 966 * Tracing continues to work after paging is enabled because the 967 * low memory addresses remain valid until everything is relocated. 968 * However, tracing through the setidt() that initializes the trace 969 * trap will crash. 970 */ 971 sgdt (%esp) 972 movl 2(%esp),%esi /* base address of bootstrap gdt */ 973 movl $R(_gdt),%edi 974 movl %edi,2(%esp) /* prepare to load kernel gdt */ 975 movl $8*18/4,%ecx 976 cld 977 rep /* copy gdt */ 978 movsl 979 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 980 movb $0x92,-8+5(%edi) 981 lgdt (%esp) 982 983 sidt (%esp) 984 movl 2(%esp),%esi /* base address of current idt */ 985 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 986 movw 8(%esi),%ax 987 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 988 movl 8+2(%esi),%eax 989 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 990 movl 24+4(%esi),%eax /* same for bpt descriptor */ 991 movw 24(%esi),%ax 992 movl %eax,R(bdb_bpt_ljmp+1) 993 movl 24+2(%esi),%eax 994 movw %ax,R(bdb_bpt_ljmp+5) 995 movl $R(_idt),%edi 996 movl %edi,2(%esp) /* prepare to load kernel idt */ 997 movl $8*4/4,%ecx 998 cld 999 rep /* copy idt */ 1000 movsl 1001 lidt (%esp) 1002 1003 addl $6,%esp 1004 1005 bdb_prepare_paging_exit: 1006 ret 1007 1008 /* Relocate debugger gdt entries and gdt and idt pointers. */ 1009 bdb_commit_paging: 1010 cmpl $0,_bdb_exists 1011 je bdb_commit_paging_exit 1012 1013 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 1014 movl $9,%ecx 1015 reloc_gdt: 1016 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 1017 addl $8,%eax /* now KERNBASE>>24 */ 1018 loop reloc_gdt 1019 1020 subl $6,%esp 1021 sgdt (%esp) 1022 addl $KERNBASE,2(%esp) 1023 lgdt (%esp) 1024 sidt (%esp) 1025 addl $KERNBASE,2(%esp) 1026 lidt (%esp) 1027 addl $6,%esp 1028 1029 int $3 1030 1031 bdb_commit_paging_exit: 1032 ret 1033 1034 #endif /* BDE_DEBUGGER */
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