locore.s revision 43434
1331722Seadler/*- 21573Srgrimes * Copyright (c) 1990 The Regents of the University of California. 31573Srgrimes * All rights reserved. 41573Srgrimes * 51573Srgrimes * This code is derived from software contributed to Berkeley by 61573Srgrimes * William Jolitz. 71573Srgrimes * 8227753Stheraven * Redistribution and use in source and binary forms, with or without 9227753Stheraven * modification, are permitted provided that the following conditions 10227753Stheraven * are met: 11227753Stheraven * 1. Redistributions of source code must retain the above copyright 12227753Stheraven * notice, this list of conditions and the following disclaimer. 131573Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 141573Srgrimes * notice, this list of conditions and the following disclaimer in the 151573Srgrimes * documentation and/or other materials provided with the distribution. 161573Srgrimes * 3. All advertising materials mentioning features or use of this software 171573Srgrimes * must display the following acknowledgement: 181573Srgrimes * This product includes software developed by the University of 191573Srgrimes * California, Berkeley and its contributors. 201573Srgrimes * 4. Neither the name of the University nor the names of its contributors 211573Srgrimes * may be used to endorse or promote products derived from this software 221573Srgrimes * without specific prior written permission. 231573Srgrimes * 241573Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 251573Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 261573Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 271573Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 281573Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 291573Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 301573Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 311573Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 321573Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 331573Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 341573Srgrimes * SUCH DAMAGE. 351573Srgrimes * 361573Srgrimes * from: @(#)locore.s 7.3 (Berkeley) 5/13/91 371573Srgrimes * $Id: locore.s,v 1.118 1998/12/08 10:22:31 kato Exp $ 381573Srgrimes * 391573Srgrimes * originally from: locore.s, by William F. Jolitz 401573Srgrimes * 4190045Sobrien * Substantially rewritten by David Greenman, Rod Grimes, 4290045Sobrien * Bruce Evans, Wolfgang Solfrank, Poul-Henning Kamp 431573Srgrimes * and many others. 441573Srgrimes */ 451573Srgrimes 461573Srgrimes#include "apm.h" 471573Srgrimes#include "opt_bootp.h" 481573Srgrimes#include "opt_ddb.h" 49132812Stjr#include "opt_nfsroot.h" 50132812Stjr#include "opt_userconfig.h" 51132812Stjr#include "opt_vm86.h" 52132812Stjr 53132812Stjr#include <sys/syscall.h> 54132812Stjr#include <sys/reboot.h> 55132812Stjr 56132812Stjr#include <machine/asmacros.h> 57132812Stjr#include <machine/cputypes.h> 58132812Stjr#include <machine/psl.h> 59132812Stjr#include <machine/pmap.h> 601573Srgrimes#include <machine/specialreg.h> 61132812Stjr 621573Srgrimes#include "assym.s" 63132812Stjr 64132812Stjr/* 651573Srgrimes * XXX 6619276Sache * 6719276Sache * Note: This version greatly munged to avoid various assembler errors 681573Srgrimes * that may be fixed in newer versions of gas. Perhaps newer versions 691573Srgrimes * will have more pleasant appearance. 7026484Sache */ 7126484Sache 7226484Sache/* 731573Srgrimes * PTmap is recursive pagemap at top of virtual address space. 74132812Stjr * Within PTmap, the page directory can be found (third indirection). 75206711Sjilles */ 76206711Sjilles .globl _PTmap,_PTD,_PTDpde 7726484Sache .set _PTmap,(PTDPTDI << PDRSHIFT) 781573Srgrimes .set _PTD,_PTmap + (PTDPTDI * PAGE_SIZE) 79288029Srodrigc .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 801573Srgrimes 81132812Stjr/* 82132812Stjr * APTmap, APTD is the alternate recursive pagemap. 83206711Sjilles * It's used when modifying another process's page tables. 84132812Stjr */ 85132812Stjr .globl _APTmap,_APTD,_APTDpde 86132812Stjr .set _APTmap,APTDPTDI << PDRSHIFT 87288029Srodrigc .set _APTD,_APTmap + (APTDPTDI * PAGE_SIZE) 88288029Srodrigc .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 89132812Stjr 90288309Sjilles/* 91288309Sjilles * Globals 9226484Sache */ 93132812Stjr .data 94132812Stjr ALIGN_DATA /* just to be sure */ 95132812Stjr 961573Srgrimes .globl HIDENAME(tmpstk) 97288309Sjilles .space 0x2000 /* space for tmpstk - temporary stack */ 98206711SjillesHIDENAME(tmpstk): 99132812Stjr 100132812Stjr .globl _boothowto,_bootdev 101132812Stjr 102132812Stjr .globl _cpu,_cpu_vendor,_cpu_id,_bootinfo 103132812Stjr .globl _cpu_high, _cpu_feature 104132812Stjr 105132812Stjr_cpu: .long 0 /* are we 386, 386sx, or 486 */ 106132812Stjr_cpu_id: .long 0 /* stepping ID */ 107132812Stjr_cpu_high: .long 0 /* highest arg to CPUID */ 108132812Stjr_cpu_feature: .long 0 /* features */ 109132812Stjr_cpu_vendor: .space 20 /* CPU origin code */ 1101573Srgrimes_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 111132812Stjr 11219132Sache_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 113288309Sjillesphysfree: .long 0 /* phys addr of next free page */ 114288309Sjilles 115288309Sjilles#ifdef SMP 1161573Srgrimescpu0pp: .long 0 /* phys addr cpu0 private pg */ 117132812Stjrcpu0pt: .long 0 /* phys addr cpu0 private pt */ 1181573Srgrimes 119132812Stjr .globl _cpu0prvpage,_cpu0prvpt 120288309Sjilles_cpu0prvpage: .long 0 /* relocated version */ 121132812Stjr_cpu0prvpt: .long 0 /* relocated version */ 1221573Srgrimes#endif /* SMP */ 1231573Srgrimes 124288309Sjilles .globl _IdlePTD 125132812Stjr_IdlePTD: .long 0 /* phys addr of kernel PTD */ 1261573Srgrimes 1271573Srgrimes#ifdef SMP 1281573Srgrimes .globl _KPTphys 1291573Srgrimes#endif 1301573Srgrimes_KPTphys: .long 0 /* phys addr of kernel page tables */ 1311573Srgrimes 1321573Srgrimes .globl _proc0paddr 133132812Stjr_proc0paddr: .long 0 /* address of proc 0 address space */ 1341573Srgrimesp0upa: .long 0 /* phys addr of proc0's UPAGES */ 1351573Srgrimes 136288309Sjilles#ifdef VM86 1371573Srgrimesvm86phystk: .long 0 /* PA of vm86/bios stack */ 1381573Srgrimes 1391573Srgrimes .globl _vm86paddr, _vm86pa 1401573Srgrimes_vm86paddr: .long 0 /* address of vm86 region */ 14125269Sjdp_vm86pa: .long 0 /* phys addr of vm86 region */ 14225269Sjdp#endif 1431573Srgrimes 1441573Srgrimes#ifdef BDE_DEBUGGER 1451573Srgrimes .globl _bdb_exists /* flag to indicate BDE debugger is present */ 1461573Srgrimes_bdb_exists: .long 0 1471573Srgrimes#endif 1481573Srgrimes 1491573Srgrimes#ifdef PC98 1501573Srgrimes .globl _pc98_system_parameter 1511573Srgrimes_pc98_system_parameter: 152288309Sjilles .space 0x240 153288309Sjilles#endif 154288309Sjilles 155288309Sjilles/********************************************************************** 156288309Sjilles * 157288309Sjilles * Some handy macros 158288309Sjilles * 159288309Sjilles */ 160288309Sjilles 1611573Srgrimes#define R(foo) ((foo)-KERNBASE) 162132812Stjr 1631573Srgrimes#define ALLOCPAGES(foo) \ 164132812Stjr movl R(physfree), %esi ; \ 165288309Sjilles movl $((foo)*PAGE_SIZE), %eax ; \ 166132812Stjr addl %esi, %eax ; \ 16726486Sache movl %eax, R(physfree) ; \ 16826486Sache movl %esi, %edi ; \ 169288309Sjilles movl $((foo)*PAGE_SIZE),%ecx ; \ 17026486Sache xorl %eax,%eax ; \ 171132812Stjr cld ; \ 172132812Stjr rep ; \ 17326484Sache stosb 17426484Sache 17526484Sache/* 17626484Sache * fillkpt 17726484Sache * eax = page frame address 17826484Sache * ebx = index into page table 179288309Sjilles * ecx = how many pages to map 18026484Sache * base = base address of page dir/table 181132812Stjr * prot = protection bits 1821573Srgrimes */ 1831573Srgrimes#define fillkpt(base, prot) \ 1841573Srgrimes shll $2,%ebx ; \ 185132812Stjr addl base,%ebx ; \ 186132812Stjr orl $PG_V,%eax ; \ 187322524Spfg orl prot,%eax ; \ 188322524Spfg1: movl %eax,(%ebx) ; \ 189132812Stjr addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 190132812Stjr addl $4,%ebx ; /* next pte */ \ 1911573Srgrimes loop 1b 1921573Srgrimes 1931573Srgrimes/* 19426484Sache * fillkptphys(prot) 195288309Sjilles * eax = physical address 196132812Stjr * ecx = how many pages to map 19719059Swosch * prot = protection bits 19819132Sache */ 199132812Stjr#define fillkptphys(prot) \ 20019059Swosch movl %eax, %ebx ; \ 201288309Sjilles shrl $PAGE_SHIFT, %ebx ; \ 202288309Sjilles fillkpt(R(_KPTphys), prot) 203288309Sjilles 204288309Sjilles .text 205288309Sjilles/********************************************************************** 206288309Sjilles * 207288309Sjilles * This is where the bootblocks start us, set the ball rolling... 208288309Sjilles * 209288309Sjilles */ 210288309SjillesNON_GPROF_ENTRY(btext) 211288309Sjilles 212288309Sjilles#ifdef PC98 213288309Sjilles /* save SYSTEM PARAMETER for resume (NS/T or other) */ 214288309Sjilles movl $0xa1400,%esi 215288309Sjilles movl $R(_pc98_system_parameter),%edi 216288309Sjilles movl $0x0240,%ecx 217288309Sjilles cld 218288309Sjilles rep 219288309Sjilles movsb 220288309Sjilles#else /* IBM-PC */ 221288309Sjilles#ifdef BDE_DEBUGGER 222288309Sjilles#ifdef BIOS_STEALS_3K 223288309Sjilles cmpl $0x0375c339,0x95504 224288309Sjilles#else 225288309Sjilles cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 226288309Sjilles#endif 227288309Sjilles jne 1f 2281573Srgrimes movb $1,R(_bdb_exists) 2291573Srgrimes1: 230132812Stjr#endif 2311573Srgrimes#endif /* PC98 */ 2321573Srgrimes 2331573Srgrimes/* Tell the bios to warmboot next time */ 23426484Sache movw $0x1234,0x472 235288029Srodrigc 236288029Srodrigc/* Set up a real frame in case the double return in newboot is executed. */ 2371573Srgrimes pushl %ebp 23826492Sache movl %esp, %ebp 239132812Stjr 240132812Stjr/* Don't trust what the BIOS gives for eflags. */ 241132812Stjr pushl $PSL_KERNEL 242227753Stheraven popfl 243227753Stheraven 2441573Srgrimes/* 2451573Srgrimes * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 2461573Srgrimes * to set %cs, %ds, %es and %ss. 2471573Srgrimes */ 2481573Srgrimes mov %ds, %ax 2491573Srgrimes mov %ax, %fs 2501573Srgrimes mov %ax, %gs 2511573Srgrimes 252323548Spfg call recover_bootinfo 2531573Srgrimes 2548870Srgrimes/* Get onto a stack that we can trust. */ 25519132Sache/* 256132812Stjr * XXX this step is delayed in case recover_bootinfo needs to return via 25719059Swosch * the old stack, but it need not be, since recover_bootinfo actually 25826484Sache * returns via the old frame. 25926484Sache */ 26026484Sache movl $R(HIDENAME(tmpstk)),%esp 26126484Sache 26226484Sache#ifdef PC98 26326492Sache testb $0x02,0x100620 /* pc98_machine_type & M_EPSON_PC98 */ 264132812Stjr jz 3f 265132812Stjr cmpb $0x0b,0x100624 /* epson_machine_id <= 0x0b */ 266132812Stjr ja 3f 267132812Stjr 268132812Stjr /* count up memory */ 269132812Stjr movl $0x100000,%eax /* next, talley remaining memory */ 27026484Sache movl $0xFFF-0x100,%ecx 271132812Stjr1: movl 0(%eax),%ebx /* save location to check */ 27226486Sache movl $0xa55a5aa5,0(%eax) /* write test pattern */ 273132812Stjr cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 274132812Stjr jne 2f 275132812Stjr movl %ebx,0(%eax) /* restore memory */ 276132812Stjr addl $PAGE_SIZE,%eax 277132812Stjr loop 1b 278132812Stjr2: subl $0x100000,%eax 27926486Sache shrl $17,%eax 28019132Sache movb %al,0x100401 281132812Stjr3: 28219059Swosch#endif 283132812Stjr 284132812Stjr call identify_cpu 285132812Stjr 286132812Stjr/* clear bss */ 287132812Stjr/* 288132812Stjr * XXX this should be done a little earlier. 289132812Stjr * 290132812Stjr * XXX we don't check that there is memory for our bss and page tables 291132812Stjr * before using it. 2921573Srgrimes * 29326484Sache * XXX the boot program somewhat bogusly clears the bss. We still have 29419059Swosch * to do it in case we were unzipped by kzipboot. Then the boot program 29519132Sache * only clears kzipboot's bss. 296132812Stjr * 29719059Swosch * XXX the gdt and idt are still somewhere in the boot program. We 298227753Stheraven * depend on the convention that the boot program is below 1MB and we 29924632Sache * are above 1MB to keep the gdt and idt away from the bss and page 300304275Sache * tables. The idt is only used if BDE_DEBUGGER is enabled. 301304275Sache */ 30217533Sache movl $R(_end),%ecx 3031573Srgrimes movl $R(_edata),%edi 3041573Srgrimes subl %edi,%ecx 3051573Srgrimes xorl %eax,%eax 306132812Stjr cld 30726492Sache rep 30826484Sache stosb 30926484Sache 3101573Srgrimes#if NAPM > 0 311#ifndef VM86 312/* 313 * XXX it's not clear that APM can live in the current environonment. 314 * Only pc-relative addressing works. 315 */ 316 call _apm_setup 317#endif 318#endif 319 320 call create_pagetables 321 322#ifdef VM86 323/* 324 * If the CPU has support for VME, turn it on. 325 */ 326 testl $CPUID_VME, R(_cpu_feature) 327 jz 1f 328 movl %cr4, %eax 329 orl $CR4_VME, %eax 330 movl %eax, %cr4 3311: 332#endif /* VM86 */ 333 334#ifdef BDE_DEBUGGER 335/* 336 * Adjust as much as possible for paging before enabling paging so that the 337 * adjustments can be traced. 338 */ 339 call bdb_prepare_paging 340#endif 341 342/* Now enable paging */ 343 movl R(_IdlePTD), %eax 344 movl %eax,%cr3 /* load ptd addr into mmu */ 345 movl %cr0,%eax /* get control word */ 346 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 347 movl %eax,%cr0 /* and let's page NOW! */ 348 349#ifdef BDE_DEBUGGER 350/* 351 * Complete the adjustments for paging so that we can keep tracing through 352 * initi386() after the low (physical) addresses for the gdt and idt become 353 * invalid. 354 */ 355 call bdb_commit_paging 356#endif 357 358 pushl $begin /* jump to high virtualized address */ 359 ret 360 361/* now running relocated at KERNBASE where the system is linked to run */ 362begin: 363 /* set up bootstrap stack */ 364 movl _proc0paddr,%esp /* location of in-kernel pages */ 365 addl $UPAGES*PAGE_SIZE,%esp /* bootstrap stack end location */ 366 xorl %eax,%eax /* mark end of frames */ 367 movl %eax,%ebp 368 movl _proc0paddr,%eax 369 movl _IdlePTD, %esi 370 movl %esi,PCB_CR3(%eax) 371 movl $_proc0,_curproc 372 373 movl physfree, %esi 374 pushl %esi /* value of first for init386(first) */ 375 call _init386 /* wire 386 chip for unix operation */ 376 popl %esi 377 378 .globl __ucodesel,__udatasel 379 380 pushl $0 /* unused */ 381 pushl __udatasel /* ss */ 382 pushl $0 /* esp - filled in by execve() */ 383 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 384 pushl __ucodesel /* cs */ 385 pushl $0 /* eip - filled in by execve() */ 386 subl $(12*4),%esp /* space for rest of registers */ 387 388 pushl %esp /* call main with frame pointer */ 389 call _main /* autoconfiguration, mountroot etc */ 390 391 hlt /* never returns to here */ 392 393/* 394 * When starting init, call this to configure the process for user 395 * mode. This will be inherited by other processes. 396 */ 397NON_GPROF_ENTRY(prepare_usermode) 398 /* 399 * Now we've run main() and determined what cpu-type we are, we can 400 * enable write protection and alignment checking on i486 cpus and 401 * above. 402 */ 403#if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU) 404 cmpl $CPUCLASS_386,_cpu_class 405 je 1f 406 movl %cr0,%eax /* get control word */ 407 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 408 movl %eax,%cr0 /* and do it */ 4091: 410#endif 411 /* 412 * on return from main(), we are process 1 413 * set up address space and stack so that we can 'return' to user mode 414 */ 415 movl __ucodesel,%eax 416 movl __udatasel,%ecx 417 418#if 0 419 movl %cx,%ds 420#endif 421 movl %cx,%es 422 movl %ax,%fs /* double map cs to fs */ 423 movl %cx,%gs /* and ds to gs */ 424 ret /* goto user! */ 425 426 427#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 428 429/* 430 * Signal trampoline, copied to top of user stack 431 */ 432NON_GPROF_ENTRY(sigcode) 433 call SIGF_HANDLER(%esp) 434 lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 435 /* copy at 8(%esp)) */ 436 pushl %eax 437 pushl %eax /* junk to fake return address */ 438 movl $SYS_sigreturn,%eax /* sigreturn() */ 439 LCALL(0x7,0) /* enter kernel with args on stack */ 440 hlt /* never gets here */ 441 ALIGN_TEXT 442_esigcode: 443 444 .data 445 .globl _szsigcode 446_szsigcode: 447 .long _esigcode-_sigcode 448 .text 449 450/********************************************************************** 451 * 452 * Recover the bootinfo passed to us from the boot program 453 * 454 */ 455recover_bootinfo: 456 /* 457 * This code is called in different ways depending on what loaded 458 * and started the kernel. This is used to detect how we get the 459 * arguments from the other code and what we do with them. 460 * 461 * Old disk boot blocks: 462 * (*btext)(howto, bootdev, cyloffset, esym); 463 * [return address == 0, and can NOT be returned to] 464 * [cyloffset was not supported by the FreeBSD boot code 465 * and always passed in as 0] 466 * [esym is also known as total in the boot code, and 467 * was never properly supported by the FreeBSD boot code] 468 * 469 * Old diskless netboot code: 470 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 471 * [return address != 0, and can NOT be returned to] 472 * If we are being booted by this code it will NOT work, 473 * so we are just going to halt if we find this case. 474 * 475 * New uniform boot code: 476 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 477 * [return address != 0, and can be returned to] 478 * 479 * There may seem to be a lot of wasted arguments in here, but 480 * that is so the newer boot code can still load very old kernels 481 * and old boot code can load new kernels. 482 */ 483 484 /* 485 * The old style disk boot blocks fake a frame on the stack and 486 * did an lret to get here. The frame on the stack has a return 487 * address of 0. 488 */ 489 cmpl $0,4(%ebp) 490 je olddiskboot 491 492 /* 493 * We have some form of return address, so this is either the 494 * old diskless netboot code, or the new uniform code. That can 495 * be detected by looking at the 5th argument, if it is 0 496 * we are being booted by the new uniform boot code. 497 */ 498 cmpl $0,24(%ebp) 499 je newboot 500 501 /* 502 * Seems we have been loaded by the old diskless boot code, we 503 * don't stand a chance of running as the diskless structure 504 * changed considerably between the two, so just halt. 505 */ 506 hlt 507 508 /* 509 * We have been loaded by the new uniform boot code. 510 * Let's check the bootinfo version, and if we do not understand 511 * it we return to the loader with a status of 1 to indicate this error 512 */ 513newboot: 514 movl 28(%ebp),%ebx /* &bootinfo.version */ 515 movl BI_VERSION(%ebx),%eax 516 cmpl $1,%eax /* We only understand version 1 */ 517 je 1f 518 movl $1,%eax /* Return status */ 519 leave 520 /* 521 * XXX this returns to our caller's caller (as is required) since 522 * we didn't set up a frame and our caller did. 523 */ 524 ret 525 5261: 527 /* 528 * If we have a kernelname copy it in 529 */ 530 movl BI_KERNELNAME(%ebx),%esi 531 cmpl $0,%esi 532 je 2f /* No kernelname */ 533 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 534 movl $R(_kernelname),%edi 535 cmpb $'/',(%esi) /* Make sure it starts with a slash */ 536 je 1f 537 movb $'/',(%edi) 538 incl %edi 539 decl %ecx 5401: 541 cld 542 rep 543 movsb 544 5452: 546 /* 547 * Determine the size of the boot loader's copy of the bootinfo 548 * struct. This is impossible to do properly because old versions 549 * of the struct don't contain a size field and there are 2 old 550 * versions with the same version number. 551 */ 552 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 553 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 554 je got_bi_size /* no, sizeless version */ 555 movl BI_SIZE(%ebx),%ecx 556got_bi_size: 557 558 /* 559 * Copy the common part of the bootinfo struct 560 */ 561 movl %ebx,%esi 562 movl $R(_bootinfo),%edi 563 cmpl $BOOTINFO_SIZE,%ecx 564 jbe got_common_bi_size 565 movl $BOOTINFO_SIZE,%ecx 566got_common_bi_size: 567 cld 568 rep 569 movsb 570 571#ifdef NFS_ROOT 572#ifndef BOOTP_NFSV3 573 /* 574 * If we have a nfs_diskless structure copy it in 575 */ 576 movl BI_NFS_DISKLESS(%ebx),%esi 577 cmpl $0,%esi 578 je olddiskboot 579 movl $R(_nfs_diskless),%edi 580 movl $NFSDISKLESS_SIZE,%ecx 581 cld 582 rep 583 movsb 584 movl $R(_nfs_diskless_valid),%edi 585 movl $1,(%edi) 586#endif 587#endif 588 589 /* 590 * The old style disk boot. 591 * (*btext)(howto, bootdev, cyloffset, esym); 592 * Note that the newer boot code just falls into here to pick 593 * up howto and bootdev, cyloffset and esym are no longer used 594 */ 595olddiskboot: 596 movl 8(%ebp),%eax 597 movl %eax,R(_boothowto) 598 movl 12(%ebp),%eax 599 movl %eax,R(_bootdev) 600 601 ret 602 603 604/********************************************************************** 605 * 606 * Identify the CPU and initialize anything special about it 607 * 608 */ 609identify_cpu: 610 611 /* Try to toggle alignment check flag; does not exist on 386. */ 612 pushfl 613 popl %eax 614 movl %eax,%ecx 615 orl $PSL_AC,%eax 616 pushl %eax 617 popfl 618 pushfl 619 popl %eax 620 xorl %ecx,%eax 621 andl $PSL_AC,%eax 622 pushl %ecx 623 popfl 624 625 testl %eax,%eax 626 jnz try486 627 628 /* NexGen CPU does not have aligment check flag. */ 629 pushfl 630 movl $0x5555, %eax 631 xorl %edx, %edx 632 movl $2, %ecx 633 clc 634 divl %ecx 635 jz trynexgen 636 popfl 637 movl $CPU_386,R(_cpu) 638 jmp 3f 639 640trynexgen: 641 popfl 642 movl $CPU_NX586,R(_cpu) 643 movl $0x4778654e,R(_cpu_vendor) # store vendor string 644 movl $0x72446e65,R(_cpu_vendor+4) 645 movl $0x6e657669,R(_cpu_vendor+8) 646 movl $0,R(_cpu_vendor+12) 647 jmp 3f 648 649try486: /* Try to toggle identification flag; does not exist on early 486s. */ 650 pushfl 651 popl %eax 652 movl %eax,%ecx 653 xorl $PSL_ID,%eax 654 pushl %eax 655 popfl 656 pushfl 657 popl %eax 658 xorl %ecx,%eax 659 andl $PSL_ID,%eax 660 pushl %ecx 661 popfl 662 663 testl %eax,%eax 664 jnz trycpuid 665 movl $CPU_486,R(_cpu) 666 667 /* 668 * Check Cyrix CPU 669 * Cyrix CPUs do not change the undefined flags following 670 * execution of the divide instruction which divides 5 by 2. 671 * 672 * Note: CPUID is enabled on M2, so it passes another way. 673 */ 674 pushfl 675 movl $0x5555, %eax 676 xorl %edx, %edx 677 movl $2, %ecx 678 clc 679 divl %ecx 680 jnc trycyrix 681 popfl 682 jmp 3f /* You may use Intel CPU. */ 683 684trycyrix: 685 popfl 686 /* 687 * IBM Bluelighting CPU also doesn't change the undefined flags. 688 * Because IBM doesn't disclose the information for Bluelighting 689 * CPU, we couldn't distinguish it from Cyrix's (including IBM 690 * brand of Cyrix CPUs). 691 */ 692 movl $0x69727943,R(_cpu_vendor) # store vendor string 693 movl $0x736e4978,R(_cpu_vendor+4) 694 movl $0x64616574,R(_cpu_vendor+8) 695 jmp 3f 696 697trycpuid: /* Use the `cpuid' instruction. */ 698 xorl %eax,%eax 699 .byte 0x0f,0xa2 # cpuid 0 700 movl %eax,R(_cpu_high) # highest capability 701 movl %ebx,R(_cpu_vendor) # store vendor string 702 movl %edx,R(_cpu_vendor+4) 703 movl %ecx,R(_cpu_vendor+8) 704 movb $0,R(_cpu_vendor+12) 705 706 movl $1,%eax 707 .byte 0x0f,0xa2 # cpuid 1 708 movl %eax,R(_cpu_id) # store cpu_id 709 movl %edx,R(_cpu_feature) # store cpu_feature 710 rorl $8,%eax # extract family type 711 andl $15,%eax 712 cmpl $5,%eax 713 jae 1f 714 715 /* less than Pentium; must be 486 */ 716 movl $CPU_486,R(_cpu) 717 jmp 3f 7181: 719 /* a Pentium? */ 720 cmpl $5,%eax 721 jne 2f 722 movl $CPU_586,R(_cpu) 723 jmp 3f 7242: 725 /* Greater than Pentium...call it a Pentium Pro */ 726 movl $CPU_686,R(_cpu) 7273: 728 ret 729 730 731/********************************************************************** 732 * 733 * Create the first page directory and its page tables. 734 * 735 */ 736 737create_pagetables: 738 739 testl $CPUID_PGE, R(_cpu_feature) 740 jz 1f 741 movl %cr4, %eax 742 orl $CR4_PGE, %eax 743 movl %eax, %cr4 7441: 745 746/* Find end of kernel image (rounded up to a page boundary). */ 747 movl $R(_end),%esi 748 749/* include symbols if loaded and useful */ 750#ifdef DDB 751 movl R(_bootinfo+BI_ESYMTAB),%edi 752 testl %edi,%edi 753 je over_symalloc 754 movl %edi,%esi 755 movl $KERNBASE,%edi 756 addl %edi,R(_bootinfo+BI_SYMTAB) 757 addl %edi,R(_bootinfo+BI_ESYMTAB) 758over_symalloc: 759#endif 760 761/* If we are told where the end of the kernel space is, believe it. */ 762 movl R(_bootinfo+BI_KERNEND),%edi 763 testl %edi,%edi 764 je no_kernend 765 movl %edi,%esi 766no_kernend: 767 768 addl $PAGE_MASK,%esi 769 andl $~PAGE_MASK,%esi 770 movl %esi,R(_KERNend) /* save end of kernel */ 771 movl %esi,R(physfree) /* next free page is at end of kernel */ 772 773/* Allocate Kernel Page Tables */ 774 ALLOCPAGES(NKPT) 775 movl %esi,R(_KPTphys) 776 777/* Allocate Page Table Directory */ 778 ALLOCPAGES(1) 779 movl %esi,R(_IdlePTD) 780 781/* Allocate UPAGES */ 782 ALLOCPAGES(UPAGES) 783 movl %esi,R(p0upa) 784 addl $KERNBASE, %esi 785 movl %esi, R(_proc0paddr) 786 787#ifdef VM86 788 ALLOCPAGES(1) /* vm86/bios stack */ 789 movl %esi,R(vm86phystk) 790 791 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 792 movl %esi,R(_vm86pa) 793 addl $KERNBASE, %esi 794 movl %esi, R(_vm86paddr) 795#endif /* VM86 */ 796 797#ifdef SMP 798/* Allocate cpu0's private data page */ 799 ALLOCPAGES(1) 800 movl %esi,R(cpu0pp) 801 addl $KERNBASE, %esi 802 movl %esi, R(_cpu0prvpage) /* relocated to KVM space */ 803 804/* Allocate cpu0's private page table for mapping priv page, apic, etc */ 805 ALLOCPAGES(1) 806 movl %esi,R(cpu0pt) 807 addl $KERNBASE, %esi 808 movl %esi, R(_cpu0prvpt) /* relocated to KVM space */ 809#endif /* SMP */ 810 811/* Map read-only from zero to the end of the kernel text section */ 812 xorl %eax, %eax 813#ifdef BDE_DEBUGGER 814/* If the debugger is present, actually map everything read-write. */ 815 cmpl $0,R(_bdb_exists) 816 jne map_read_write 817#endif 818 xorl %edx,%edx 819 820#if !defined(SMP) 821 testl $CPUID_PGE, R(_cpu_feature) 822 jz 2f 823 orl $PG_G,%edx 824#endif 825 8262: movl $R(_etext),%ecx 827 addl $PAGE_MASK,%ecx 828 shrl $PAGE_SHIFT,%ecx 829 fillkptphys(%edx) 830 831/* Map read-write, data, bss and symbols */ 832 movl $R(_etext),%eax 833 addl $PAGE_MASK, %eax 834 andl $~PAGE_MASK, %eax 835map_read_write: 836 movl $PG_RW,%edx 837#if !defined(SMP) 838 testl $CPUID_PGE, R(_cpu_feature) 839 jz 1f 840 orl $PG_G,%edx 841#endif 842 8431: movl R(_KERNend),%ecx 844 subl %eax,%ecx 845 shrl $PAGE_SHIFT,%ecx 846 fillkptphys(%edx) 847 848/* Map page directory. */ 849 movl R(_IdlePTD), %eax 850 movl $1, %ecx 851 fillkptphys($PG_RW) 852 853/* Map proc0's UPAGES in the physical way ... */ 854 movl R(p0upa), %eax 855 movl $UPAGES, %ecx 856 fillkptphys($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#ifdef VM86 864/* Map space for the vm86 region */ 865 movl R(vm86phystk), %eax 866 movl $4, %ecx 867 fillkptphys($PG_RW) 868 869/* Map page 0 into the vm86 page table */ 870 movl $0, %eax 871 movl $0, %ebx 872 movl $1, %ecx 873 fillkpt(R(_vm86pa), $PG_RW|PG_U) 874 875/* ...likewise for the ISA hole */ 876 movl $ISA_HOLE_START, %eax 877 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 878 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 879 fillkpt(R(_vm86pa), $PG_RW|PG_U) 880#endif /* VM86 */ 881 882#ifdef SMP 883/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 884 movl R(cpu0pp), %eax 885 movl $1, %ecx 886 fillkptphys($PG_RW) 887 888/* Map cpu0's private page table into global kmem FWIW */ 889 movl R(cpu0pt), %eax 890 movl $1, %ecx 891 fillkptphys($PG_RW) 892 893/* Map the private page into the private page table into private space */ 894 movl R(cpu0pp), %eax 895 movl $0, %ebx /* pte offset = 0 */ 896 movl $1, %ecx /* one private page coming right up */ 897 fillkpt(R(cpu0pt), $PG_RW) 898 899/* Map the page table page into private space */ 900 movl R(cpu0pt), %eax 901 movl $1, %ebx /* pte offset = 1 */ 902 movl $1, %ecx /* one private pt coming right up */ 903 fillkpt(R(cpu0pt), $PG_RW) 904 905/* ... and put the page table table in the pde. */ 906 movl R(cpu0pt), %eax 907 movl $MPPTDI, %ebx 908 movl $1, %ecx 909 fillkpt(R(_IdlePTD), $PG_RW) 910 911/* Fakeup VA for the local apic to allow early traps. */ 912 ALLOCPAGES(1) 913 movl %esi, %eax 914 movl $2, %ebx /* pte offset = 2 */ 915 movl $1, %ecx /* one private pt coming right up */ 916 fillkpt(R(cpu0pt), $PG_RW) 917 918/* Initialize mp lock to allow early traps */ 919 movl $1, R(_mp_lock) 920 921/* Initialize my_idlePTD to IdlePTD */ 922 movl R(cpu0pp), %eax 923 movl R(_IdlePTD), %ecx 924 movl %ecx,GD_MY_IDLEPTD(%eax) 925/* Initialize IdlePTDS[0] */ 926 addl $KERNBASE, %ecx 927 movl %ecx, R(CNAME(IdlePTDS)) 928 929#endif /* SMP */ 930 931/* install a pde for temporary double map of bottom of VA */ 932 movl R(_KPTphys), %eax 933 xorl %ebx, %ebx 934 movl $1, %ecx 935 fillkpt(R(_IdlePTD), $PG_RW) 936 937/* install pde's for pt's */ 938 movl R(_KPTphys), %eax 939 movl $KPTDI, %ebx 940 movl $NKPT, %ecx 941 fillkpt(R(_IdlePTD), $PG_RW) 942 943/* install a pde recursively mapping page directory as a page table */ 944 movl R(_IdlePTD), %eax 945 movl $PTDPTDI, %ebx 946 movl $1,%ecx 947 fillkpt(R(_IdlePTD), $PG_RW) 948 949 ret 950 951#ifdef BDE_DEBUGGER 952bdb_prepare_paging: 953 cmpl $0,R(_bdb_exists) 954 je bdb_prepare_paging_exit 955 956 subl $6,%esp 957 958 /* 959 * Copy and convert debugger entries from the bootstrap gdt and idt 960 * to the kernel gdt and idt. Everything is still in low memory. 961 * Tracing continues to work after paging is enabled because the 962 * low memory addresses remain valid until everything is relocated. 963 * However, tracing through the setidt() that initializes the trace 964 * trap will crash. 965 */ 966 sgdt (%esp) 967 movl 2(%esp),%esi /* base address of bootstrap gdt */ 968 movl $R(_gdt),%edi 969 movl %edi,2(%esp) /* prepare to load kernel gdt */ 970 movl $8*18/4,%ecx 971 cld 972 rep /* copy gdt */ 973 movsl 974 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 975 movb $0x92,-8+5(%edi) 976 lgdt (%esp) 977 978 sidt (%esp) 979 movl 2(%esp),%esi /* base address of current idt */ 980 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 981 movw 8(%esi),%ax 982 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 983 movl 8+2(%esi),%eax 984 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 985 movl 24+4(%esi),%eax /* same for bpt descriptor */ 986 movw 24(%esi),%ax 987 movl %eax,R(bdb_bpt_ljmp+1) 988 movl 24+2(%esi),%eax 989 movw %ax,R(bdb_bpt_ljmp+5) 990 movl $R(_idt),%edi 991 movl %edi,2(%esp) /* prepare to load kernel idt */ 992 movl $8*4/4,%ecx 993 cld 994 rep /* copy idt */ 995 movsl 996 lidt (%esp) 997 998 addl $6,%esp 999 1000bdb_prepare_paging_exit: 1001 ret 1002 1003/* Relocate debugger gdt entries and gdt and idt pointers. */ 1004bdb_commit_paging: 1005 cmpl $0,_bdb_exists 1006 je bdb_commit_paging_exit 1007 1008 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 1009 movl $9,%ecx 1010reloc_gdt: 1011 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 1012 addl $8,%eax /* now KERNBASE>>24 */ 1013 loop reloc_gdt 1014 1015 subl $6,%esp 1016 sgdt (%esp) 1017 addl $KERNBASE,2(%esp) 1018 lgdt (%esp) 1019 sidt (%esp) 1020 addl $KERNBASE,2(%esp) 1021 lidt (%esp) 1022 addl $6,%esp 1023 1024 int $3 1025 1026bdb_commit_paging_exit: 1027 ret 1028 1029#endif /* BDE_DEBUGGER */ 1030