locore.s revision 70928
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: head/sys/i386/i386/locore.s 70928 2001-01-11 14:46:26Z jake $ 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_nfsroot.h" 48 49#include <sys/syscall.h> 50#include <sys/reboot.h> 51 52#include <machine/asmacros.h> 53#include <machine/cputypes.h> 54#include <machine/psl.h> 55#include <machine/pmap.h> 56#include <machine/specialreg.h> 57 58#include "assym.s" 59 60/* 61 * XXX 62 * 63 * Note: This version greatly munged to avoid various assembler errors 64 * that may be fixed in newer versions of gas. Perhaps newer versions 65 * will have more pleasant appearance. 66 */ 67 68/* 69 * PTmap is recursive pagemap at top of virtual address space. 70 * Within PTmap, the page directory can be found (third indirection). 71 */ 72 .globl _PTmap,_PTD,_PTDpde 73 .set _PTmap,(PTDPTDI << PDRSHIFT) 74 .set _PTD,_PTmap + (PTDPTDI * PAGE_SIZE) 75 .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 76 77/* 78 * APTmap, APTD is the alternate recursive pagemap. 79 * It's used when modifying another process's page tables. 80 */ 81 .globl _APTmap,_APTD,_APTDpde 82 .set _APTmap,APTDPTDI << PDRSHIFT 83 .set _APTD,_APTmap + (APTDPTDI * PAGE_SIZE) 84 .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 85 86#ifdef SMP 87/* 88 * Define layout of per-cpu address space. 89 * This is "constructed" in locore.s on the BSP and in mp_machdep.c 90 * for each AP. DO NOT REORDER THESE WITHOUT UPDATING THE REST! 91 */ 92 .globl _SMP_prvspace, _lapic 93 .set _SMP_prvspace,(MPPTDI << PDRSHIFT) 94 .set _lapic,_SMP_prvspace + (NPTEPG-1) * PAGE_SIZE 95#endif /* SMP */ 96 97/* 98 * Globals 99 */ 100 .data 101 ALIGN_DATA /* just to be sure */ 102 103 .globl HIDENAME(tmpstk) 104 .space 0x2000 /* space for tmpstk - temporary stack */ 105HIDENAME(tmpstk): 106 107 .globl _boothowto,_bootdev 108 109 .globl _cpu,_cpu_vendor,_cpu_id,_bootinfo 110 .globl _cpu_high, _cpu_feature 111 112_cpu: .long 0 /* are we 386, 386sx, or 486 */ 113_cpu_id: .long 0 /* stepping ID */ 114_cpu_high: .long 0 /* highest arg to CPUID */ 115_cpu_feature: .long 0 /* features */ 116_cpu_vendor: .space 20 /* CPU origin code */ 117_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 118 119_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 120physfree: .long 0 /* phys addr of next free page */ 121 122#ifdef SMP 123 .globl _cpu0prvpage 124cpu0pp: .long 0 /* phys addr cpu0 private pg */ 125_cpu0prvpage: .long 0 /* relocated version */ 126 127 .globl _SMPpt 128SMPptpa: .long 0 /* phys addr SMP page table */ 129_SMPpt: .long 0 /* relocated version */ 130#endif /* SMP */ 131 132 .globl _IdlePTD 133_IdlePTD: .long 0 /* phys addr of kernel PTD */ 134 135#ifdef SMP 136 .globl _KPTphys 137#endif 138_KPTphys: .long 0 /* phys addr of kernel page tables */ 139 140 .globl _proc0paddr 141_proc0paddr: .long 0 /* address of proc 0 address space */ 142p0upa: .long 0 /* phys addr of proc0's UPAGES */ 143 144vm86phystk: .long 0 /* PA of vm86/bios stack */ 145 146 .globl _vm86paddr, _vm86pa 147_vm86paddr: .long 0 /* address of vm86 region */ 148_vm86pa: .long 0 /* phys addr of vm86 region */ 149 150#ifdef BDE_DEBUGGER 151 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 152_bdb_exists: .long 0 153#endif 154 155#ifdef PC98 156 .globl _pc98_system_parameter 157_pc98_system_parameter: 158 .space 0x240 159#endif 160 161/********************************************************************** 162 * 163 * Some handy macros 164 * 165 */ 166 167#define R(foo) ((foo)-KERNBASE) 168 169#define ALLOCPAGES(foo) \ 170 movl R(physfree), %esi ; \ 171 movl $((foo)*PAGE_SIZE), %eax ; \ 172 addl %esi, %eax ; \ 173 movl %eax, R(physfree) ; \ 174 movl %esi, %edi ; \ 175 movl $((foo)*PAGE_SIZE),%ecx ; \ 176 xorl %eax,%eax ; \ 177 cld ; \ 178 rep ; \ 179 stosb 180 181/* 182 * fillkpt 183 * eax = page frame address 184 * ebx = index into page table 185 * ecx = how many pages to map 186 * base = base address of page dir/table 187 * prot = protection bits 188 */ 189#define fillkpt(base, prot) \ 190 shll $2,%ebx ; \ 191 addl base,%ebx ; \ 192 orl $PG_V,%eax ; \ 193 orl prot,%eax ; \ 1941: movl %eax,(%ebx) ; \ 195 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 196 addl $4,%ebx ; /* next pte */ \ 197 loop 1b 198 199/* 200 * fillkptphys(prot) 201 * eax = physical address 202 * ecx = how many pages to map 203 * prot = protection bits 204 */ 205#define fillkptphys(prot) \ 206 movl %eax, %ebx ; \ 207 shrl $PAGE_SHIFT, %ebx ; \ 208 fillkpt(R(_KPTphys), prot) 209 210 .text 211/********************************************************************** 212 * 213 * This is where the bootblocks start us, set the ball rolling... 214 * 215 */ 216NON_GPROF_ENTRY(btext) 217 218#ifdef PC98 219 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 220 movl $0xa1400,%esi 221 movl $R(_pc98_system_parameter),%edi 222 movl $0x0240,%ecx 223 cld 224 rep 225 movsb 226#else /* IBM-PC */ 227#ifdef BDE_DEBUGGER 228#ifdef BIOS_STEALS_3K 229 cmpl $0x0375c339,0x95504 230#else 231 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 232#endif 233 jne 1f 234 movb $1,R(_bdb_exists) 2351: 236#endif 237/* Tell the bios to warmboot next time */ 238 movw $0x1234,0x472 239#endif /* PC98 */ 240 241/* Set up a real frame in case the double return in newboot is executed. */ 242 pushl %ebp 243 movl %esp, %ebp 244 245/* Don't trust what the BIOS gives for eflags. */ 246 pushl $PSL_KERNEL 247 popfl 248 249/* 250 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 251 * to set %cs, %ds, %es and %ss. 252 */ 253 mov %ds, %ax 254 mov %ax, %fs 255 mov %ax, %gs 256 257 call recover_bootinfo 258 259/* Get onto a stack that we can trust. */ 260/* 261 * XXX this step is delayed in case recover_bootinfo needs to return via 262 * the old stack, but it need not be, since recover_bootinfo actually 263 * returns via the old frame. 264 */ 265 movl $R(HIDENAME(tmpstk)),%esp 266 267#ifdef PC98 268 /* pc98_machine_type & M_EPSON_PC98 */ 269 testb $0x02,R(_pc98_system_parameter)+220 270 jz 3f 271 /* epson_machine_id <= 0x0b */ 272 cmpb $0x0b,R(_pc98_system_parameter)+224 273 ja 3f 274 275 /* count up memory */ 276 movl $0x100000,%eax /* next, talley remaining memory */ 277 movl $0xFFF-0x100,%ecx 2781: movl 0(%eax),%ebx /* save location to check */ 279 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 280 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 281 jne 2f 282 movl %ebx,0(%eax) /* restore memory */ 283 addl $PAGE_SIZE,%eax 284 loop 1b 2852: subl $0x100000,%eax 286 shrl $17,%eax 287 movb %al,R(_pc98_system_parameter)+1 2883: 289 290 movw R(_pc98_system_parameter+0x86),%ax 291 movw %ax,R(_cpu_id) 292#endif 293 294 call identify_cpu 295 296/* clear bss */ 297/* 298 * XXX this should be done a little earlier. 299 * 300 * XXX we don't check that there is memory for our bss and page tables 301 * before using it. 302 * 303 * XXX the boot program somewhat bogusly clears the bss. We still have 304 * to do it in case we were unzipped by kzipboot. Then the boot program 305 * only clears kzipboot's bss. 306 * 307 * XXX the gdt and idt are still somewhere in the boot program. We 308 * depend on the convention that the boot program is below 1MB and we 309 * are above 1MB to keep the gdt and idt away from the bss and page 310 * tables. The idt is only used if BDE_DEBUGGER is enabled. 311 */ 312 movl $R(_end),%ecx 313 movl $R(_edata),%edi 314 subl %edi,%ecx 315 xorl %eax,%eax 316 cld 317 rep 318 stosb 319 320 call create_pagetables 321 322/* 323 * If the CPU has support for VME, turn it on. 324 */ 325 testl $CPUID_VME, R(_cpu_feature) 326 jz 1f 327 movl %cr4, %eax 328 orl $CR4_VME, %eax 329 movl %eax, %cr4 3301: 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,%eax /* location of in-kernel pages */ 363 leal UPAGES*PAGE_SIZE(%eax),%esp /* bootstrap stack end location */ 364 365 xorl %ebp,%ebp /* mark end of frames */ 366 367 movl _IdlePTD,%esi 368 movl %esi,PCB_CR3(%eax) 369 370 pushl physfree /* value of first for init386(first) */ 371 call _init386 /* wire 386 chip for unix operation */ 372 373 /* 374 * Clean up the stack in a way that db_numargs() understands, so 375 * that backtraces in ddb don't underrun the stack. Traps for 376 * inaccessible memory are more fatal than usual this early. 377 */ 378 addl $4,%esp 379 380 call _mi_startup /* autoconfiguration, mountroot etc */ 381 /* NOTREACHED */ 382 addl $0,%esp /* for db_numargs() again */ 383 384/* 385 * Signal trampoline, copied to top of user stack 386 */ 387NON_GPROF_ENTRY(sigcode) 388 call *SIGF_HANDLER(%esp) /* call signal handler */ 389 lea SIGF_UC(%esp),%eax /* get ucontext_t */ 390 pushl %eax 391 testl $PSL_VM,UC_EFLAGS(%eax) 392 jne 9f 393 movl UC_GS(%eax),%gs /* restore %gs */ 3949: 395 movl $SYS_sigreturn,%eax 396 pushl %eax /* junk to fake return addr. */ 397 int $0x80 /* enter kernel with args */ 3980: jmp 0b 399 400 ALIGN_TEXT 401_osigcode: 402 call *SIGF_HANDLER(%esp) /* call signal handler */ 403 lea SIGF_SC(%esp),%eax /* get sigcontext */ 404 pushl %eax 405 testl $PSL_VM,SC_PS(%eax) 406 jne 9f 407 movl SC_GS(%eax),%gs /* restore %gs */ 4089: 409 movl $0x01d516,SC_TRAPNO(%eax) /* magic: 0ldSiG */ 410 movl $SYS_sigreturn,%eax 411 pushl %eax /* junk to fake return addr. */ 412 int $0x80 /* enter kernel with args */ 4130: jmp 0b 414 415 ALIGN_TEXT 416_esigcode: 417 418 .data 419 .globl _szsigcode, _szosigcode 420_szsigcode: 421 .long _esigcode-_sigcode 422_szosigcode: 423 .long _esigcode-_osigcode 424 .text 425 426/********************************************************************** 427 * 428 * Recover the bootinfo passed to us from the boot program 429 * 430 */ 431recover_bootinfo: 432 /* 433 * This code is called in different ways depending on what loaded 434 * and started the kernel. This is used to detect how we get the 435 * arguments from the other code and what we do with them. 436 * 437 * Old disk boot blocks: 438 * (*btext)(howto, bootdev, cyloffset, esym); 439 * [return address == 0, and can NOT be returned to] 440 * [cyloffset was not supported by the FreeBSD boot code 441 * and always passed in as 0] 442 * [esym is also known as total in the boot code, and 443 * was never properly supported by the FreeBSD boot code] 444 * 445 * Old diskless netboot code: 446 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 447 * [return address != 0, and can NOT be returned to] 448 * If we are being booted by this code it will NOT work, 449 * so we are just going to halt if we find this case. 450 * 451 * New uniform boot code: 452 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 453 * [return address != 0, and can be returned to] 454 * 455 * There may seem to be a lot of wasted arguments in here, but 456 * that is so the newer boot code can still load very old kernels 457 * and old boot code can load new kernels. 458 */ 459 460 /* 461 * The old style disk boot blocks fake a frame on the stack and 462 * did an lret to get here. The frame on the stack has a return 463 * address of 0. 464 */ 465 cmpl $0,4(%ebp) 466 je olddiskboot 467 468 /* 469 * We have some form of return address, so this is either the 470 * old diskless netboot code, or the new uniform code. That can 471 * be detected by looking at the 5th argument, if it is 0 472 * we are being booted by the new uniform boot code. 473 */ 474 cmpl $0,24(%ebp) 475 je newboot 476 477 /* 478 * Seems we have been loaded by the old diskless boot code, we 479 * don't stand a chance of running as the diskless structure 480 * changed considerably between the two, so just halt. 481 */ 482 hlt 483 484 /* 485 * We have been loaded by the new uniform boot code. 486 * Let's check the bootinfo version, and if we do not understand 487 * it we return to the loader with a status of 1 to indicate this error 488 */ 489newboot: 490 movl 28(%ebp),%ebx /* &bootinfo.version */ 491 movl BI_VERSION(%ebx),%eax 492 cmpl $1,%eax /* We only understand version 1 */ 493 je 1f 494 movl $1,%eax /* Return status */ 495 leave 496 /* 497 * XXX this returns to our caller's caller (as is required) since 498 * we didn't set up a frame and our caller did. 499 */ 500 ret 501 5021: 503 /* 504 * If we have a kernelname copy it in 505 */ 506 movl BI_KERNELNAME(%ebx),%esi 507 cmpl $0,%esi 508 je 2f /* No kernelname */ 509 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 510 movl $R(_kernelname),%edi 511 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 512 je 1f 513 movb $'/',(%edi) 514 incl %edi 515 decl %ecx 5161: 517 cld 518 rep 519 movsb 520 5212: 522 /* 523 * Determine the size of the boot loader's copy of the bootinfo 524 * struct. This is impossible to do properly because old versions 525 * of the struct don't contain a size field and there are 2 old 526 * versions with the same version number. 527 */ 528 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 529 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 530 je got_bi_size /* no, sizeless version */ 531 movl BI_SIZE(%ebx),%ecx 532got_bi_size: 533 534 /* 535 * Copy the common part of the bootinfo struct 536 */ 537 movl %ebx,%esi 538 movl $R(_bootinfo),%edi 539 cmpl $BOOTINFO_SIZE,%ecx 540 jbe got_common_bi_size 541 movl $BOOTINFO_SIZE,%ecx 542got_common_bi_size: 543 cld 544 rep 545 movsb 546 547#ifdef NFS_ROOT 548#ifndef BOOTP_NFSV3 549 /* 550 * If we have a nfs_diskless structure copy it in 551 */ 552 movl BI_NFS_DISKLESS(%ebx),%esi 553 cmpl $0,%esi 554 je olddiskboot 555 movl $R(_nfs_diskless),%edi 556 movl $NFSDISKLESS_SIZE,%ecx 557 cld 558 rep 559 movsb 560 movl $R(_nfs_diskless_valid),%edi 561 movl $1,(%edi) 562#endif 563#endif 564 565 /* 566 * The old style disk boot. 567 * (*btext)(howto, bootdev, cyloffset, esym); 568 * Note that the newer boot code just falls into here to pick 569 * up howto and bootdev, cyloffset and esym are no longer used 570 */ 571olddiskboot: 572 movl 8(%ebp),%eax 573 movl %eax,R(_boothowto) 574 movl 12(%ebp),%eax 575 movl %eax,R(_bootdev) 576 577 ret 578 579 580/********************************************************************** 581 * 582 * Identify the CPU and initialize anything special about it 583 * 584 */ 585identify_cpu: 586 587 /* Try to toggle alignment check flag; does not exist on 386. */ 588 pushfl 589 popl %eax 590 movl %eax,%ecx 591 orl $PSL_AC,%eax 592 pushl %eax 593 popfl 594 pushfl 595 popl %eax 596 xorl %ecx,%eax 597 andl $PSL_AC,%eax 598 pushl %ecx 599 popfl 600 601 testl %eax,%eax 602 jnz try486 603 604 /* NexGen CPU does not have aligment check flag. */ 605 pushfl 606 movl $0x5555, %eax 607 xorl %edx, %edx 608 movl $2, %ecx 609 clc 610 divl %ecx 611 jz trynexgen 612 popfl 613 movl $CPU_386,R(_cpu) 614 jmp 3f 615 616trynexgen: 617 popfl 618 movl $CPU_NX586,R(_cpu) 619 movl $0x4778654e,R(_cpu_vendor) # store vendor string 620 movl $0x72446e65,R(_cpu_vendor+4) 621 movl $0x6e657669,R(_cpu_vendor+8) 622 movl $0,R(_cpu_vendor+12) 623 jmp 3f 624 625try486: /* Try to toggle identification flag; does not exist on early 486s. */ 626 pushfl 627 popl %eax 628 movl %eax,%ecx 629 xorl $PSL_ID,%eax 630 pushl %eax 631 popfl 632 pushfl 633 popl %eax 634 xorl %ecx,%eax 635 andl $PSL_ID,%eax 636 pushl %ecx 637 popfl 638 639 testl %eax,%eax 640 jnz trycpuid 641 movl $CPU_486,R(_cpu) 642 643 /* 644 * Check Cyrix CPU 645 * Cyrix CPUs do not change the undefined flags following 646 * execution of the divide instruction which divides 5 by 2. 647 * 648 * Note: CPUID is enabled on M2, so it passes another way. 649 */ 650 pushfl 651 movl $0x5555, %eax 652 xorl %edx, %edx 653 movl $2, %ecx 654 clc 655 divl %ecx 656 jnc trycyrix 657 popfl 658 jmp 3f /* You may use Intel CPU. */ 659 660trycyrix: 661 popfl 662 /* 663 * IBM Bluelighting CPU also doesn't change the undefined flags. 664 * Because IBM doesn't disclose the information for Bluelighting 665 * CPU, we couldn't distinguish it from Cyrix's (including IBM 666 * brand of Cyrix CPUs). 667 */ 668 movl $0x69727943,R(_cpu_vendor) # store vendor string 669 movl $0x736e4978,R(_cpu_vendor+4) 670 movl $0x64616574,R(_cpu_vendor+8) 671 jmp 3f 672 673trycpuid: /* Use the `cpuid' instruction. */ 674 xorl %eax,%eax 675 cpuid # cpuid 0 676 movl %eax,R(_cpu_high) # highest capability 677 movl %ebx,R(_cpu_vendor) # store vendor string 678 movl %edx,R(_cpu_vendor+4) 679 movl %ecx,R(_cpu_vendor+8) 680 movb $0,R(_cpu_vendor+12) 681 682 movl $1,%eax 683 cpuid # cpuid 1 684 movl %eax,R(_cpu_id) # store cpu_id 685 movl %edx,R(_cpu_feature) # store cpu_feature 686 rorl $8,%eax # extract family type 687 andl $15,%eax 688 cmpl $5,%eax 689 jae 1f 690 691 /* less than Pentium; must be 486 */ 692 movl $CPU_486,R(_cpu) 693 jmp 3f 6941: 695 /* a Pentium? */ 696 cmpl $5,%eax 697 jne 2f 698 movl $CPU_586,R(_cpu) 699 jmp 3f 7002: 701 /* Greater than Pentium...call it a Pentium Pro */ 702 movl $CPU_686,R(_cpu) 7033: 704 ret 705 706 707/********************************************************************** 708 * 709 * Create the first page directory and its page tables. 710 * 711 */ 712 713create_pagetables: 714 715 testl $CPUID_PGE, R(_cpu_feature) 716 jz 1f 717 movl %cr4, %eax 718 orl $CR4_PGE, %eax 719 movl %eax, %cr4 7201: 721 722/* Find end of kernel image (rounded up to a page boundary). */ 723 movl $R(_end),%esi 724 725/* Include symbols, if any. */ 726 movl R(_bootinfo+BI_ESYMTAB),%edi 727 testl %edi,%edi 728 je over_symalloc 729 movl %edi,%esi 730 movl $KERNBASE,%edi 731 addl %edi,R(_bootinfo+BI_SYMTAB) 732 addl %edi,R(_bootinfo+BI_ESYMTAB) 733over_symalloc: 734 735/* If we are told where the end of the kernel space is, believe it. */ 736 movl R(_bootinfo+BI_KERNEND),%edi 737 testl %edi,%edi 738 je no_kernend 739 movl %edi,%esi 740no_kernend: 741 742 addl $PAGE_MASK,%esi 743 andl $~PAGE_MASK,%esi 744 movl %esi,R(_KERNend) /* save end of kernel */ 745 movl %esi,R(physfree) /* next free page is at end of kernel */ 746 747/* Allocate Kernel Page Tables */ 748 ALLOCPAGES(NKPT) 749 movl %esi,R(_KPTphys) 750 751/* Allocate Page Table Directory */ 752 ALLOCPAGES(1) 753 movl %esi,R(_IdlePTD) 754 755/* Allocate UPAGES */ 756 ALLOCPAGES(UPAGES) 757 movl %esi,R(p0upa) 758 addl $KERNBASE, %esi 759 movl %esi, R(_proc0paddr) 760 761 ALLOCPAGES(1) /* vm86/bios stack */ 762 movl %esi,R(vm86phystk) 763 764 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 765 movl %esi,R(_vm86pa) 766 addl $KERNBASE, %esi 767 movl %esi, R(_vm86paddr) 768 769#ifdef SMP 770/* Allocate cpu0's private data page */ 771 ALLOCPAGES(1) 772 movl %esi,R(cpu0pp) 773 addl $KERNBASE, %esi 774 movl %esi, R(_cpu0prvpage) /* relocated to KVM space */ 775 776/* Allocate SMP page table page */ 777 ALLOCPAGES(1) 778 movl %esi,R(SMPptpa) 779 addl $KERNBASE, %esi 780 movl %esi, R(_SMPpt) /* relocated to KVM space */ 781#endif /* SMP */ 782 783/* Map read-only from zero to the end of the kernel text section */ 784 xorl %eax, %eax 785#ifdef BDE_DEBUGGER 786/* If the debugger is present, actually map everything read-write. */ 787 cmpl $0,R(_bdb_exists) 788 jne map_read_write 789#endif 790 xorl %edx,%edx 791 792#if !defined(SMP) 793 testl $CPUID_PGE, R(_cpu_feature) 794 jz 2f 795 orl $PG_G,%edx 796#endif 797 7982: movl $R(_etext),%ecx 799 addl $PAGE_MASK,%ecx 800 shrl $PAGE_SHIFT,%ecx 801 fillkptphys(%edx) 802 803/* Map read-write, data, bss and symbols */ 804 movl $R(_etext),%eax 805 addl $PAGE_MASK, %eax 806 andl $~PAGE_MASK, %eax 807map_read_write: 808 movl $PG_RW,%edx 809#if !defined(SMP) 810 testl $CPUID_PGE, R(_cpu_feature) 811 jz 1f 812 orl $PG_G,%edx 813#endif 814 8151: movl R(_KERNend),%ecx 816 subl %eax,%ecx 817 shrl $PAGE_SHIFT,%ecx 818 fillkptphys(%edx) 819 820/* Map page directory. */ 821 movl R(_IdlePTD), %eax 822 movl $1, %ecx 823 fillkptphys($PG_RW) 824 825/* Map proc0's UPAGES in the physical way ... */ 826 movl R(p0upa), %eax 827 movl $UPAGES, %ecx 828 fillkptphys($PG_RW) 829 830/* Map ISA hole */ 831 movl $ISA_HOLE_START, %eax 832 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 833 fillkptphys($PG_RW) 834 835/* Map space for the vm86 region */ 836 movl R(vm86phystk), %eax 837 movl $4, %ecx 838 fillkptphys($PG_RW) 839 840/* Map page 0 into the vm86 page table */ 841 movl $0, %eax 842 movl $0, %ebx 843 movl $1, %ecx 844 fillkpt(R(_vm86pa), $PG_RW|PG_U) 845 846/* ...likewise for the ISA hole */ 847 movl $ISA_HOLE_START, %eax 848 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 849 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 850 fillkpt(R(_vm86pa), $PG_RW|PG_U) 851 852#ifdef SMP 853/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 854 movl R(cpu0pp), %eax 855 movl $1, %ecx 856 fillkptphys($PG_RW) 857 858/* Map SMP page table page into global kmem FWIW */ 859 movl R(SMPptpa), %eax 860 movl $1, %ecx 861 fillkptphys($PG_RW) 862 863/* Map the private page into the SMP page table */ 864 movl R(cpu0pp), %eax 865 movl $0, %ebx /* pte offset = 0 */ 866 movl $1, %ecx /* one private page coming right up */ 867 fillkpt(R(SMPptpa), $PG_RW) 868 869/* ... and put the page table table in the pde. */ 870 movl R(SMPptpa), %eax 871 movl $MPPTDI, %ebx 872 movl $1, %ecx 873 fillkpt(R(_IdlePTD), $PG_RW) 874 875/* Fakeup VA for the local apic to allow early traps. */ 876 ALLOCPAGES(1) 877 movl %esi, %eax 878 movl $(NPTEPG-1), %ebx /* pte offset = NTEPG-1 */ 879 movl $1, %ecx /* one private pt coming right up */ 880 fillkpt(R(SMPptpa), $PG_RW) 881#endif /* SMP */ 882 883/* install a pde for temporary double map of bottom of VA */ 884 movl R(_KPTphys), %eax 885 xorl %ebx, %ebx 886 movl $1, %ecx 887 fillkpt(R(_IdlePTD), $PG_RW) 888 889/* install pde's for pt's */ 890 movl R(_KPTphys), %eax 891 movl $KPTDI, %ebx 892 movl $NKPT, %ecx 893 fillkpt(R(_IdlePTD), $PG_RW) 894 895/* install a pde recursively mapping page directory as a page table */ 896 movl R(_IdlePTD), %eax 897 movl $PTDPTDI, %ebx 898 movl $1,%ecx 899 fillkpt(R(_IdlePTD), $PG_RW) 900 901 ret 902 903#ifdef BDE_DEBUGGER 904bdb_prepare_paging: 905 cmpl $0,R(_bdb_exists) 906 je bdb_prepare_paging_exit 907 908 subl $6,%esp 909 910 /* 911 * Copy and convert debugger entries from the bootstrap gdt and idt 912 * to the kernel gdt and idt. Everything is still in low memory. 913 * Tracing continues to work after paging is enabled because the 914 * low memory addresses remain valid until everything is relocated. 915 * However, tracing through the setidt() that initializes the trace 916 * trap will crash. 917 */ 918 sgdt (%esp) 919 movl 2(%esp),%esi /* base address of bootstrap gdt */ 920 movl $R(_gdt),%edi 921 movl %edi,2(%esp) /* prepare to load kernel gdt */ 922 movl $8*18/4,%ecx 923 cld 924 rep /* copy gdt */ 925 movsl 926 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 927 movb $0x92,-8+5(%edi) 928 lgdt (%esp) 929 930 sidt (%esp) 931 movl 2(%esp),%esi /* base address of current idt */ 932 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 933 movw 8(%esi),%ax 934 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 935 movl 8+2(%esi),%eax 936 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 937 movl 24+4(%esi),%eax /* same for bpt descriptor */ 938 movw 24(%esi),%ax 939 movl %eax,R(bdb_bpt_ljmp+1) 940 movl 24+2(%esi),%eax 941 movw %ax,R(bdb_bpt_ljmp+5) 942 movl R(_idt),%edi 943 movl %edi,2(%esp) /* prepare to load kernel idt */ 944 movl $8*4/4,%ecx 945 cld 946 rep /* copy idt */ 947 movsl 948 lidt (%esp) 949 950 addl $6,%esp 951 952bdb_prepare_paging_exit: 953 ret 954 955/* Relocate debugger gdt entries and gdt and idt pointers. */ 956bdb_commit_paging: 957 cmpl $0,_bdb_exists 958 je bdb_commit_paging_exit 959 960 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 961 movl $9,%ecx 962reloc_gdt: 963 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 964 addl $8,%eax /* now KERNBASE>>24 */ 965 loop reloc_gdt 966 967 subl $6,%esp 968 sgdt (%esp) 969 addl $KERNBASE,2(%esp) 970 lgdt (%esp) 971 sidt (%esp) 972 addl $KERNBASE,2(%esp) 973 lidt (%esp) 974 addl $6,%esp 975 976 int $3 977 978bdb_commit_paging_exit: 979 ret 980 981#endif /* BDE_DEBUGGER */ 982