locore.s revision 64529
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 64529 2000-08-11 09:05:12Z peter $ 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/* 87 * Globals 88 */ 89 .data 90 ALIGN_DATA /* just to be sure */ 91 92 .globl HIDENAME(tmpstk) 93 .space 0x2000 /* space for tmpstk - temporary stack */ 94HIDENAME(tmpstk): 95 96 .globl _boothowto,_bootdev 97 98 .globl _cpu,_cpu_vendor,_cpu_id,_bootinfo 99 .globl _cpu_high, _cpu_feature 100 101_cpu: .long 0 /* are we 386, 386sx, or 486 */ 102_cpu_id: .long 0 /* stepping ID */ 103_cpu_high: .long 0 /* highest arg to CPUID */ 104_cpu_feature: .long 0 /* features */ 105_cpu_vendor: .space 20 /* CPU origin code */ 106_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 107 108_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 109physfree: .long 0 /* phys addr of next free page */ 110 111#ifdef SMP 112 .globl _cpu0prvpage 113cpu0pp: .long 0 /* phys addr cpu0 private pg */ 114_cpu0prvpage: .long 0 /* relocated version */ 115 116 .globl _SMPpt 117SMPptpa: .long 0 /* phys addr SMP page table */ 118_SMPpt: .long 0 /* relocated version */ 119#endif /* SMP */ 120 121 .globl _IdlePTD 122_IdlePTD: .long 0 /* phys addr of kernel PTD */ 123 124#ifdef SMP 125 .globl _KPTphys 126#endif 127_KPTphys: .long 0 /* phys addr of kernel page tables */ 128 129 .globl _proc0paddr 130_proc0paddr: .long 0 /* address of proc 0 address space */ 131p0upa: .long 0 /* phys addr of proc0's UPAGES */ 132 133vm86phystk: .long 0 /* PA of vm86/bios stack */ 134 135 .globl _vm86paddr, _vm86pa 136_vm86paddr: .long 0 /* address of vm86 region */ 137_vm86pa: .long 0 /* phys addr of vm86 region */ 138 139#ifdef BDE_DEBUGGER 140 .globl _bdb_exists /* flag to indicate BDE debugger is present */ 141_bdb_exists: .long 0 142#endif 143 144#ifdef PC98 145 .globl _pc98_system_parameter 146_pc98_system_parameter: 147 .space 0x240 148#endif 149 150/********************************************************************** 151 * 152 * Some handy macros 153 * 154 */ 155 156#define R(foo) ((foo)-KERNBASE) 157 158#define ALLOCPAGES(foo) \ 159 movl R(physfree), %esi ; \ 160 movl $((foo)*PAGE_SIZE), %eax ; \ 161 addl %esi, %eax ; \ 162 movl %eax, R(physfree) ; \ 163 movl %esi, %edi ; \ 164 movl $((foo)*PAGE_SIZE),%ecx ; \ 165 xorl %eax,%eax ; \ 166 cld ; \ 167 rep ; \ 168 stosb 169 170/* 171 * fillkpt 172 * eax = page frame address 173 * ebx = index into page table 174 * ecx = how many pages to map 175 * base = base address of page dir/table 176 * prot = protection bits 177 */ 178#define fillkpt(base, prot) \ 179 shll $2,%ebx ; \ 180 addl base,%ebx ; \ 181 orl $PG_V,%eax ; \ 182 orl prot,%eax ; \ 1831: movl %eax,(%ebx) ; \ 184 addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 185 addl $4,%ebx ; /* next pte */ \ 186 loop 1b 187 188/* 189 * fillkptphys(prot) 190 * eax = physical address 191 * ecx = how many pages to map 192 * prot = protection bits 193 */ 194#define fillkptphys(prot) \ 195 movl %eax, %ebx ; \ 196 shrl $PAGE_SHIFT, %ebx ; \ 197 fillkpt(R(_KPTphys), prot) 198 199 .text 200/********************************************************************** 201 * 202 * This is where the bootblocks start us, set the ball rolling... 203 * 204 */ 205NON_GPROF_ENTRY(btext) 206 207#ifdef PC98 208 /* save SYSTEM PARAMETER for resume (NS/T or other) */ 209 movl $0xa1400,%esi 210 movl $R(_pc98_system_parameter),%edi 211 movl $0x0240,%ecx 212 cld 213 rep 214 movsb 215#else /* IBM-PC */ 216#ifdef BDE_DEBUGGER 217#ifdef BIOS_STEALS_3K 218 cmpl $0x0375c339,0x95504 219#else 220 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 221#endif 222 jne 1f 223 movb $1,R(_bdb_exists) 2241: 225#endif 226/* Tell the bios to warmboot next time */ 227 movw $0x1234,0x472 228#endif /* PC98 */ 229 230/* Set up a real frame in case the double return in newboot is executed. */ 231 pushl %ebp 232 movl %esp, %ebp 233 234/* Don't trust what the BIOS gives for eflags. */ 235 pushl $PSL_KERNEL 236 popfl 237 238/* 239 * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 240 * to set %cs, %ds, %es and %ss. 241 */ 242 mov %ds, %ax 243 mov %ax, %fs 244 mov %ax, %gs 245 246 call recover_bootinfo 247 248/* Get onto a stack that we can trust. */ 249/* 250 * XXX this step is delayed in case recover_bootinfo needs to return via 251 * the old stack, but it need not be, since recover_bootinfo actually 252 * returns via the old frame. 253 */ 254 movl $R(HIDENAME(tmpstk)),%esp 255 256#ifdef PC98 257 /* pc98_machine_type & M_EPSON_PC98 */ 258 testb $0x02,R(_pc98_system_parameter)+220 259 jz 3f 260 /* epson_machine_id <= 0x0b */ 261 cmpb $0x0b,R(_pc98_system_parameter)+224 262 ja 3f 263 264 /* count up memory */ 265 movl $0x100000,%eax /* next, talley remaining memory */ 266 movl $0xFFF-0x100,%ecx 2671: movl 0(%eax),%ebx /* save location to check */ 268 movl $0xa55a5aa5,0(%eax) /* write test pattern */ 269 cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 270 jne 2f 271 movl %ebx,0(%eax) /* restore memory */ 272 addl $PAGE_SIZE,%eax 273 loop 1b 2742: subl $0x100000,%eax 275 shrl $17,%eax 276 movb %al,R(_pc98_system_parameter)+1 2773: 278 279 movw R(_pc98_system_parameter+0x86),%ax 280 movw %ax,R(_cpu_id) 281#endif 282 283 call identify_cpu 284 285/* clear bss */ 286/* 287 * XXX this should be done a little earlier. 288 * 289 * XXX we don't check that there is memory for our bss and page tables 290 * before using it. 291 * 292 * XXX the boot program somewhat bogusly clears the bss. We still have 293 * to do it in case we were unzipped by kzipboot. Then the boot program 294 * only clears kzipboot's bss. 295 * 296 * XXX the gdt and idt are still somewhere in the boot program. We 297 * depend on the convention that the boot program is below 1MB and we 298 * are above 1MB to keep the gdt and idt away from the bss and page 299 * tables. The idt is only used if BDE_DEBUGGER is enabled. 300 */ 301 movl $R(_end),%ecx 302 movl $R(_edata),%edi 303 subl %edi,%ecx 304 xorl %eax,%eax 305 cld 306 rep 307 stosb 308 309 call create_pagetables 310 311/* 312 * If the CPU has support for VME, turn it on. 313 */ 314 testl $CPUID_VME, R(_cpu_feature) 315 jz 1f 316 movl %cr4, %eax 317 orl $CR4_VME, %eax 318 movl %eax, %cr4 3191: 320 321#ifdef BDE_DEBUGGER 322/* 323 * Adjust as much as possible for paging before enabling paging so that the 324 * adjustments can be traced. 325 */ 326 call bdb_prepare_paging 327#endif 328 329/* Now enable paging */ 330 movl R(_IdlePTD), %eax 331 movl %eax,%cr3 /* load ptd addr into mmu */ 332 movl %cr0,%eax /* get control word */ 333 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 334 movl %eax,%cr0 /* and let's page NOW! */ 335 336#ifdef BDE_DEBUGGER 337/* 338 * Complete the adjustments for paging so that we can keep tracing through 339 * initi386() after the low (physical) addresses for the gdt and idt become 340 * invalid. 341 */ 342 call bdb_commit_paging 343#endif 344 345 pushl $begin /* jump to high virtualized address */ 346 ret 347 348/* now running relocated at KERNBASE where the system is linked to run */ 349begin: 350 /* set up bootstrap stack */ 351 movl _proc0paddr,%esp /* location of in-kernel pages */ 352 addl $UPAGES*PAGE_SIZE,%esp /* bootstrap stack end location */ 353 xorl %eax,%eax /* mark end of frames */ 354 movl %eax,%ebp 355 movl _proc0paddr,%eax 356 movl _IdlePTD, %esi 357 movl %esi,PCB_CR3(%eax) 358 359 movl physfree, %esi 360 pushl %esi /* value of first for init386(first) */ 361 call _init386 /* wire 386 chip for unix operation */ 362 popl %esi 363 364 call _mi_startup /* autoconfiguration, mountroot etc */ 365 366 hlt /* never returns to here */ 367 368/* 369 * Signal trampoline, copied to top of user stack 370 */ 371NON_GPROF_ENTRY(sigcode) 372 call *SIGF_HANDLER(%esp) /* call signal handler */ 373 lea SIGF_UC(%esp),%eax /* get ucontext_t */ 374 pushl %eax 375 testl $PSL_VM,UC_EFLAGS(%eax) 376 jne 9f 377 movl UC_GS(%eax),%gs /* restore %gs */ 3789: 379 movl $SYS_sigreturn,%eax 380 pushl %eax /* junk to fake return addr. */ 381 int $0x80 /* enter kernel with args */ 3820: jmp 0b 383 384 ALIGN_TEXT 385_osigcode: 386 call *SIGF_HANDLER(%esp) /* call signal handler */ 387 lea SIGF_SC(%esp),%eax /* get sigcontext */ 388 pushl %eax 389 testl $PSL_VM,SC_PS(%eax) 390 jne 9f 391 movl SC_GS(%eax),%gs /* restore %gs */ 3929: 393 movl $0x01d516,SC_TRAPNO(%eax) /* magic: 0ldSiG */ 394 movl $SYS_sigreturn,%eax 395 pushl %eax /* junk to fake return addr. */ 396 int $0x80 /* enter kernel with args */ 3970: jmp 0b 398 399 ALIGN_TEXT 400_esigcode: 401 402 .data 403 .globl _szsigcode, _szosigcode 404_szsigcode: 405 .long _esigcode-_sigcode 406_szosigcode: 407 .long _esigcode-_osigcode 408 .text 409 410/********************************************************************** 411 * 412 * Recover the bootinfo passed to us from the boot program 413 * 414 */ 415recover_bootinfo: 416 /* 417 * This code is called in different ways depending on what loaded 418 * and started the kernel. This is used to detect how we get the 419 * arguments from the other code and what we do with them. 420 * 421 * Old disk boot blocks: 422 * (*btext)(howto, bootdev, cyloffset, esym); 423 * [return address == 0, and can NOT be returned to] 424 * [cyloffset was not supported by the FreeBSD boot code 425 * and always passed in as 0] 426 * [esym is also known as total in the boot code, and 427 * was never properly supported by the FreeBSD boot code] 428 * 429 * Old diskless netboot code: 430 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 431 * [return address != 0, and can NOT be returned to] 432 * If we are being booted by this code it will NOT work, 433 * so we are just going to halt if we find this case. 434 * 435 * New uniform boot code: 436 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 437 * [return address != 0, and can be returned to] 438 * 439 * There may seem to be a lot of wasted arguments in here, but 440 * that is so the newer boot code can still load very old kernels 441 * and old boot code can load new kernels. 442 */ 443 444 /* 445 * The old style disk boot blocks fake a frame on the stack and 446 * did an lret to get here. The frame on the stack has a return 447 * address of 0. 448 */ 449 cmpl $0,4(%ebp) 450 je olddiskboot 451 452 /* 453 * We have some form of return address, so this is either the 454 * old diskless netboot code, or the new uniform code. That can 455 * be detected by looking at the 5th argument, if it is 0 456 * we are being booted by the new uniform boot code. 457 */ 458 cmpl $0,24(%ebp) 459 je newboot 460 461 /* 462 * Seems we have been loaded by the old diskless boot code, we 463 * don't stand a chance of running as the diskless structure 464 * changed considerably between the two, so just halt. 465 */ 466 hlt 467 468 /* 469 * We have been loaded by the new uniform boot code. 470 * Let's check the bootinfo version, and if we do not understand 471 * it we return to the loader with a status of 1 to indicate this error 472 */ 473newboot: 474 movl 28(%ebp),%ebx /* &bootinfo.version */ 475 movl BI_VERSION(%ebx),%eax 476 cmpl $1,%eax /* We only understand version 1 */ 477 je 1f 478 movl $1,%eax /* Return status */ 479 leave 480 /* 481 * XXX this returns to our caller's caller (as is required) since 482 * we didn't set up a frame and our caller did. 483 */ 484 ret 485 4861: 487 /* 488 * If we have a kernelname copy it in 489 */ 490 movl BI_KERNELNAME(%ebx),%esi 491 cmpl $0,%esi 492 je 2f /* No kernelname */ 493 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 494 movl $R(_kernelname),%edi 495 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 496 je 1f 497 movb $'/',(%edi) 498 incl %edi 499 decl %ecx 5001: 501 cld 502 rep 503 movsb 504 5052: 506 /* 507 * Determine the size of the boot loader's copy of the bootinfo 508 * struct. This is impossible to do properly because old versions 509 * of the struct don't contain a size field and there are 2 old 510 * versions with the same version number. 511 */ 512 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 513 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 514 je got_bi_size /* no, sizeless version */ 515 movl BI_SIZE(%ebx),%ecx 516got_bi_size: 517 518 /* 519 * Copy the common part of the bootinfo struct 520 */ 521 movl %ebx,%esi 522 movl $R(_bootinfo),%edi 523 cmpl $BOOTINFO_SIZE,%ecx 524 jbe got_common_bi_size 525 movl $BOOTINFO_SIZE,%ecx 526got_common_bi_size: 527 cld 528 rep 529 movsb 530 531#ifdef NFS_ROOT 532#ifndef BOOTP_NFSV3 533 /* 534 * If we have a nfs_diskless structure copy it in 535 */ 536 movl BI_NFS_DISKLESS(%ebx),%esi 537 cmpl $0,%esi 538 je olddiskboot 539 movl $R(_nfs_diskless),%edi 540 movl $NFSDISKLESS_SIZE,%ecx 541 cld 542 rep 543 movsb 544 movl $R(_nfs_diskless_valid),%edi 545 movl $1,(%edi) 546#endif 547#endif 548 549 /* 550 * The old style disk boot. 551 * (*btext)(howto, bootdev, cyloffset, esym); 552 * Note that the newer boot code just falls into here to pick 553 * up howto and bootdev, cyloffset and esym are no longer used 554 */ 555olddiskboot: 556 movl 8(%ebp),%eax 557 movl %eax,R(_boothowto) 558 movl 12(%ebp),%eax 559 movl %eax,R(_bootdev) 560 561 ret 562 563 564/********************************************************************** 565 * 566 * Identify the CPU and initialize anything special about it 567 * 568 */ 569identify_cpu: 570 571 /* Try to toggle alignment check flag; does not exist on 386. */ 572 pushfl 573 popl %eax 574 movl %eax,%ecx 575 orl $PSL_AC,%eax 576 pushl %eax 577 popfl 578 pushfl 579 popl %eax 580 xorl %ecx,%eax 581 andl $PSL_AC,%eax 582 pushl %ecx 583 popfl 584 585 testl %eax,%eax 586 jnz try486 587 588 /* NexGen CPU does not have aligment check flag. */ 589 pushfl 590 movl $0x5555, %eax 591 xorl %edx, %edx 592 movl $2, %ecx 593 clc 594 divl %ecx 595 jz trynexgen 596 popfl 597 movl $CPU_386,R(_cpu) 598 jmp 3f 599 600trynexgen: 601 popfl 602 movl $CPU_NX586,R(_cpu) 603 movl $0x4778654e,R(_cpu_vendor) # store vendor string 604 movl $0x72446e65,R(_cpu_vendor+4) 605 movl $0x6e657669,R(_cpu_vendor+8) 606 movl $0,R(_cpu_vendor+12) 607 jmp 3f 608 609try486: /* Try to toggle identification flag; does not exist on early 486s. */ 610 pushfl 611 popl %eax 612 movl %eax,%ecx 613 xorl $PSL_ID,%eax 614 pushl %eax 615 popfl 616 pushfl 617 popl %eax 618 xorl %ecx,%eax 619 andl $PSL_ID,%eax 620 pushl %ecx 621 popfl 622 623 testl %eax,%eax 624 jnz trycpuid 625 movl $CPU_486,R(_cpu) 626 627 /* 628 * Check Cyrix CPU 629 * Cyrix CPUs do not change the undefined flags following 630 * execution of the divide instruction which divides 5 by 2. 631 * 632 * Note: CPUID is enabled on M2, so it passes another way. 633 */ 634 pushfl 635 movl $0x5555, %eax 636 xorl %edx, %edx 637 movl $2, %ecx 638 clc 639 divl %ecx 640 jnc trycyrix 641 popfl 642 jmp 3f /* You may use Intel CPU. */ 643 644trycyrix: 645 popfl 646 /* 647 * IBM Bluelighting CPU also doesn't change the undefined flags. 648 * Because IBM doesn't disclose the information for Bluelighting 649 * CPU, we couldn't distinguish it from Cyrix's (including IBM 650 * brand of Cyrix CPUs). 651 */ 652 movl $0x69727943,R(_cpu_vendor) # store vendor string 653 movl $0x736e4978,R(_cpu_vendor+4) 654 movl $0x64616574,R(_cpu_vendor+8) 655 jmp 3f 656 657trycpuid: /* Use the `cpuid' instruction. */ 658 xorl %eax,%eax 659 .byte 0x0f,0xa2 # cpuid 0 660 movl %eax,R(_cpu_high) # highest capability 661 movl %ebx,R(_cpu_vendor) # store vendor string 662 movl %edx,R(_cpu_vendor+4) 663 movl %ecx,R(_cpu_vendor+8) 664 movb $0,R(_cpu_vendor+12) 665 666 movl $1,%eax 667 .byte 0x0f,0xa2 # cpuid 1 668 movl %eax,R(_cpu_id) # store cpu_id 669 movl %edx,R(_cpu_feature) # store cpu_feature 670 rorl $8,%eax # extract family type 671 andl $15,%eax 672 cmpl $5,%eax 673 jae 1f 674 675 /* less than Pentium; must be 486 */ 676 movl $CPU_486,R(_cpu) 677 jmp 3f 6781: 679 /* a Pentium? */ 680 cmpl $5,%eax 681 jne 2f 682 movl $CPU_586,R(_cpu) 683 jmp 3f 6842: 685 /* Greater than Pentium...call it a Pentium Pro */ 686 movl $CPU_686,R(_cpu) 6873: 688 ret 689 690 691/********************************************************************** 692 * 693 * Create the first page directory and its page tables. 694 * 695 */ 696 697create_pagetables: 698 699 testl $CPUID_PGE, R(_cpu_feature) 700 jz 1f 701 movl %cr4, %eax 702 orl $CR4_PGE, %eax 703 movl %eax, %cr4 7041: 705 706/* Find end of kernel image (rounded up to a page boundary). */ 707 movl $R(_end),%esi 708 709/* Include symbols, if any. */ 710 movl R(_bootinfo+BI_ESYMTAB),%edi 711 testl %edi,%edi 712 je over_symalloc 713 movl %edi,%esi 714 movl $KERNBASE,%edi 715 addl %edi,R(_bootinfo+BI_SYMTAB) 716 addl %edi,R(_bootinfo+BI_ESYMTAB) 717over_symalloc: 718 719/* If we are told where the end of the kernel space is, believe it. */ 720 movl R(_bootinfo+BI_KERNEND),%edi 721 testl %edi,%edi 722 je no_kernend 723 movl %edi,%esi 724no_kernend: 725 726 addl $PAGE_MASK,%esi 727 andl $~PAGE_MASK,%esi 728 movl %esi,R(_KERNend) /* save end of kernel */ 729 movl %esi,R(physfree) /* next free page is at end of kernel */ 730 731/* Allocate Kernel Page Tables */ 732 ALLOCPAGES(NKPT) 733 movl %esi,R(_KPTphys) 734 735/* Allocate Page Table Directory */ 736 ALLOCPAGES(1) 737 movl %esi,R(_IdlePTD) 738 739/* Allocate UPAGES */ 740 ALLOCPAGES(UPAGES) 741 movl %esi,R(p0upa) 742 addl $KERNBASE, %esi 743 movl %esi, R(_proc0paddr) 744 745 ALLOCPAGES(1) /* vm86/bios stack */ 746 movl %esi,R(vm86phystk) 747 748 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 749 movl %esi,R(_vm86pa) 750 addl $KERNBASE, %esi 751 movl %esi, R(_vm86paddr) 752 753#ifdef SMP 754/* Allocate cpu0's private data page */ 755 ALLOCPAGES(1) 756 movl %esi,R(cpu0pp) 757 addl $KERNBASE, %esi 758 movl %esi, R(_cpu0prvpage) /* relocated to KVM space */ 759 760/* Allocate SMP page table page */ 761 ALLOCPAGES(1) 762 movl %esi,R(SMPptpa) 763 addl $KERNBASE, %esi 764 movl %esi, R(_SMPpt) /* relocated to KVM space */ 765#endif /* SMP */ 766 767/* Map read-only from zero to the end of the kernel text section */ 768 xorl %eax, %eax 769#ifdef BDE_DEBUGGER 770/* If the debugger is present, actually map everything read-write. */ 771 cmpl $0,R(_bdb_exists) 772 jne map_read_write 773#endif 774 xorl %edx,%edx 775 776#if !defined(SMP) 777 testl $CPUID_PGE, R(_cpu_feature) 778 jz 2f 779 orl $PG_G,%edx 780#endif 781 7822: movl $R(_etext),%ecx 783 addl $PAGE_MASK,%ecx 784 shrl $PAGE_SHIFT,%ecx 785 fillkptphys(%edx) 786 787/* Map read-write, data, bss and symbols */ 788 movl $R(_etext),%eax 789 addl $PAGE_MASK, %eax 790 andl $~PAGE_MASK, %eax 791map_read_write: 792 movl $PG_RW,%edx 793#if !defined(SMP) 794 testl $CPUID_PGE, R(_cpu_feature) 795 jz 1f 796 orl $PG_G,%edx 797#endif 798 7991: movl R(_KERNend),%ecx 800 subl %eax,%ecx 801 shrl $PAGE_SHIFT,%ecx 802 fillkptphys(%edx) 803 804/* Map page directory. */ 805 movl R(_IdlePTD), %eax 806 movl $1, %ecx 807 fillkptphys($PG_RW) 808 809/* Map proc0's UPAGES in the physical way ... */ 810 movl R(p0upa), %eax 811 movl $UPAGES, %ecx 812 fillkptphys($PG_RW) 813 814/* Map ISA hole */ 815 movl $ISA_HOLE_START, %eax 816 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 817 fillkptphys($PG_RW) 818 819/* Map space for the vm86 region */ 820 movl R(vm86phystk), %eax 821 movl $4, %ecx 822 fillkptphys($PG_RW) 823 824/* Map page 0 into the vm86 page table */ 825 movl $0, %eax 826 movl $0, %ebx 827 movl $1, %ecx 828 fillkpt(R(_vm86pa), $PG_RW|PG_U) 829 830/* ...likewise for the ISA hole */ 831 movl $ISA_HOLE_START, %eax 832 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 833 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 834 fillkpt(R(_vm86pa), $PG_RW|PG_U) 835 836#ifdef SMP 837/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 838 movl R(cpu0pp), %eax 839 movl $1, %ecx 840 fillkptphys($PG_RW) 841 842/* Map SMP page table page into global kmem FWIW */ 843 movl R(SMPptpa), %eax 844 movl $1, %ecx 845 fillkptphys($PG_RW) 846 847/* Map the private page into the SMP page table */ 848 movl R(cpu0pp), %eax 849 movl $0, %ebx /* pte offset = 0 */ 850 movl $1, %ecx /* one private page coming right up */ 851 fillkpt(R(SMPptpa), $PG_RW) 852 853/* ... and put the page table table in the pde. */ 854 movl R(SMPptpa), %eax 855 movl $MPPTDI, %ebx 856 movl $1, %ecx 857 fillkpt(R(_IdlePTD), $PG_RW) 858 859/* Fakeup VA for the local apic to allow early traps. */ 860 ALLOCPAGES(1) 861 movl %esi, %eax 862 movl $(NPTEPG-1), %ebx /* pte offset = NTEPG-1 */ 863 movl $1, %ecx /* one private pt coming right up */ 864 fillkpt(R(SMPptpa), $PG_RW) 865 866/* Initialize mp lock to allow early traps */ 867 movl $1, R(_mp_lock) 868#endif /* SMP */ 869 870/* install a pde for temporary double map of bottom of VA */ 871 movl R(_KPTphys), %eax 872 xorl %ebx, %ebx 873 movl $1, %ecx 874 fillkpt(R(_IdlePTD), $PG_RW) 875 876/* install pde's for pt's */ 877 movl R(_KPTphys), %eax 878 movl $KPTDI, %ebx 879 movl $NKPT, %ecx 880 fillkpt(R(_IdlePTD), $PG_RW) 881 882/* install a pde recursively mapping page directory as a page table */ 883 movl R(_IdlePTD), %eax 884 movl $PTDPTDI, %ebx 885 movl $1,%ecx 886 fillkpt(R(_IdlePTD), $PG_RW) 887 888 ret 889 890#ifdef BDE_DEBUGGER 891bdb_prepare_paging: 892 cmpl $0,R(_bdb_exists) 893 je bdb_prepare_paging_exit 894 895 subl $6,%esp 896 897 /* 898 * Copy and convert debugger entries from the bootstrap gdt and idt 899 * to the kernel gdt and idt. Everything is still in low memory. 900 * Tracing continues to work after paging is enabled because the 901 * low memory addresses remain valid until everything is relocated. 902 * However, tracing through the setidt() that initializes the trace 903 * trap will crash. 904 */ 905 sgdt (%esp) 906 movl 2(%esp),%esi /* base address of bootstrap gdt */ 907 movl $R(_gdt),%edi 908 movl %edi,2(%esp) /* prepare to load kernel gdt */ 909 movl $8*18/4,%ecx 910 cld 911 rep /* copy gdt */ 912 movsl 913 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 914 movb $0x92,-8+5(%edi) 915 lgdt (%esp) 916 917 sidt (%esp) 918 movl 2(%esp),%esi /* base address of current idt */ 919 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 920 movw 8(%esi),%ax 921 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 922 movl 8+2(%esi),%eax 923 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 924 movl 24+4(%esi),%eax /* same for bpt descriptor */ 925 movw 24(%esi),%ax 926 movl %eax,R(bdb_bpt_ljmp+1) 927 movl 24+2(%esi),%eax 928 movw %ax,R(bdb_bpt_ljmp+5) 929 movl R(_idt),%edi 930 movl %edi,2(%esp) /* prepare to load kernel idt */ 931 movl $8*4/4,%ecx 932 cld 933 rep /* copy idt */ 934 movsl 935 lidt (%esp) 936 937 addl $6,%esp 938 939bdb_prepare_paging_exit: 940 ret 941 942/* Relocate debugger gdt entries and gdt and idt pointers. */ 943bdb_commit_paging: 944 cmpl $0,_bdb_exists 945 je bdb_commit_paging_exit 946 947 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 948 movl $9,%ecx 949reloc_gdt: 950 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 951 addl $8,%eax /* now KERNBASE>>24 */ 952 loop reloc_gdt 953 954 subl $6,%esp 955 sgdt (%esp) 956 addl $KERNBASE,2(%esp) 957 lgdt (%esp) 958 sidt (%esp) 959 addl $KERNBASE,2(%esp) 960 lidt (%esp) 961 addl $6,%esp 962 963 int $3 964 965bdb_commit_paging_exit: 966 ret 967 968#endif /* BDE_DEBUGGER */ 969