locore.s revision 54121
1139825Simp/*- 21156Sjkh * Copyright (c) 1990 The Regents of the University of California. 31156Sjkh * All rights reserved. 41156Sjkh * 51156Sjkh * This code is derived from software contributed to Berkeley by 61156Sjkh * William Jolitz. 71156Sjkh * 81156Sjkh * Redistribution and use in source and binary forms, with or without 91156Sjkh * modification, are permitted provided that the following conditions 101156Sjkh * are met: 111156Sjkh * 1. Redistributions of source code must retain the above copyright 121156Sjkh * notice, this list of conditions and the following disclaimer. 131156Sjkh * 2. Redistributions in binary form must reproduce the above copyright 141156Sjkh * notice, this list of conditions and the following disclaimer in the 151156Sjkh * documentation and/or other materials provided with the distribution. 161156Sjkh * 3. All advertising materials mentioning features or use of this software 1713771Smpp * must display the following acknowledgement: 181156Sjkh * This product includes software developed by the University of 191156Sjkh * California, Berkeley and its contributors. 201156Sjkh * 4. Neither the name of the University nor the names of its contributors 211156Sjkh * may be used to endorse or promote products derived from this software 221156Sjkh * without specific prior written permission. 231156Sjkh * 241156Sjkh * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 251156Sjkh * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 261156Sjkh * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 271156Sjkh * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 281156Sjkh * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 291156Sjkh * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 3050473Speter * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 311156Sjkh * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 321156Sjkh * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 331156Sjkh * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34697Spaul * SUCH DAMAGE. 35697Spaul * 361156Sjkh * from: @(#)locore.s 7.3 (Berkeley) 5/13/91 371156Sjkh * $FreeBSD: head/sys/i386/i386/locore.s 54121 1999-12-04 10:53:39Z marcel $ 381156Sjkh * 39697Spaul * originally from: locore.s, by William F. Jolitz 40697Spaul * 41102284Speter * Substantially rewritten by David Greenman, Rod Grimes, 42102284Speter * Bruce Evans, Wolfgang Solfrank, Poul-Henning Kamp 43697Spaul * and many others. 4433137Sjdp */ 4533137Sjdp 46697Spaul#include "opt_bootp.h" 4713771Smpp#include "opt_ddb.h" 48697Spaul#include "opt_nfsroot.h" 491156Sjkh#include "opt_userconfig.h" 501156Sjkh 51697Spaul#include <sys/syscall.h> 52697Spaul#include <sys/reboot.h> 531156Sjkh 541156Sjkh#include <machine/asmacros.h> 551156Sjkh#include <machine/cputypes.h> 561156Sjkh#include <machine/psl.h> 571156Sjkh#include <machine/pmap.h> 581156Sjkh#include <machine/specialreg.h> 591156Sjkh 60697Spaul#include "assym.s" 61697Spaul 62697Spaul/* 631156Sjkh * XXX 641156Sjkh * 65697Spaul * Note: This version greatly munged to avoid various assembler errors 66697Spaul * that may be fixed in newer versions of gas. Perhaps newer versions 67697Spaul * will have more pleasant appearance. 681156Sjkh */ 691156Sjkh 701156Sjkh/* 711156Sjkh * PTmap is recursive pagemap at top of virtual address space. 721156Sjkh * Within PTmap, the page directory can be found (third indirection). 731156Sjkh */ 741156Sjkh .globl _PTmap,_PTD,_PTDpde 751156Sjkh .set _PTmap,(PTDPTDI << PDRSHIFT) 761156Sjkh .set _PTD,_PTmap + (PTDPTDI * PAGE_SIZE) 77697Spaul .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 78697Spaul 79697Spaul/* 80697Spaul * APTmap, APTD is the alternate recursive pagemap. 81697Spaul * It's used when modifying another process's page tables. 82697Spaul */ 83697Spaul .globl _APTmap,_APTD,_APTDpde 841156Sjkh .set _APTmap,APTDPTDI << PDRSHIFT 85697Spaul .set _APTD,_APTmap + (APTDPTDI * PAGE_SIZE) 86697Spaul .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 87697Spaul 88697Spaul/* 8931584Sjdp * Globals 9031584Sjdp */ 91697Spaul .data 92697Spaul ALIGN_DATA /* just to be sure */ 93697Spaul 94697Spaul .globl HIDENAME(tmpstk) 95697Spaul .space 0x2000 /* space for tmpstk - temporary stack */ 96697SpaulHIDENAME(tmpstk): 97697Spaul 98697Spaul .globl _boothowto,_bootdev 99697Spaul 1001156Sjkh .globl _cpu,_cpu_vendor,_cpu_id,_bootinfo 101697Spaul .globl _cpu_high, _cpu_feature 102697Spaul 1031156Sjkh_cpu: .long 0 /* are we 386, 386sx, or 486 */ 1041156Sjkh_cpu_id: .long 0 /* stepping ID */ 1051156Sjkh_cpu_high: .long 0 /* highest arg to CPUID */ 10618591Speter_cpu_feature: .long 0 /* features */ 1071156Sjkh_cpu_vendor: .space 20 /* CPU origin code */ 1081156Sjkh_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 1091156Sjkh 1101156Sjkh_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 1111156Sjkhphysfree: .long 0 /* phys addr of next free page */ 1121156Sjkh 1131156Sjkh#ifdef SMP 1141156Sjkh .globl _cpu0prvpage 1151156Sjkhcpu0pp: .long 0 /* phys addr cpu0 private pg */ 1161156Sjkh_cpu0prvpage: .long 0 /* relocated version */ 1171156Sjkh 118697Spaul .globl _SMPpt 119697SpaulSMPptpa: .long 0 /* phys addr SMP page table */ 120697Spaul_SMPpt: .long 0 /* relocated version */ 1211156Sjkh#endif /* SMP */ 122697Spaul 123697Spaul .globl _IdlePTD 1241156Sjkh_IdlePTD: .long 0 /* phys addr of kernel PTD */ 125697Spaul 126697Spaul#ifdef SMP 127697Spaul .globl _KPTphys 1281156Sjkh#endif 1291156Sjkh_KPTphys: .long 0 /* phys addr of kernel page tables */ 130697Spaul 131697Spaul .globl _proc0paddr 132697Spaul_proc0paddr: .long 0 /* address of proc 0 address space */ 133697Spaulp0upa: .long 0 /* phys addr of proc0's UPAGES */ 134697Spaul 135697Spaulvm86phystk: .long 0 /* PA of vm86/bios stack */ 136697Spaul 1371156Sjkh .globl _vm86paddr, _vm86pa 1381156Sjkh_vm86paddr: .long 0 /* address of vm86 region */ 1391156Sjkh_vm86pa: .long 0 /* phys addr of vm86 region */ 1401156Sjkh 1411156Sjkh#ifdef BDE_DEBUGGER 142697Spaul .globl _bdb_exists /* flag to indicate BDE debugger is present */ 143697Spaul_bdb_exists: .long 0 144697Spaul#endif 145697Spaul 146697Spaul#ifdef PC98 1471156Sjkh .globl _pc98_system_parameter 1481156Sjkh_pc98_system_parameter: 1491156Sjkh .space 0x240 1501156Sjkh#endif 1511156Sjkh 1521156Sjkh/********************************************************************** 1531156Sjkh * 1541156Sjkh * Some handy macros 155697Spaul * 156697Spaul */ 157697Spaul 1589335Sdfr#define R(foo) ((foo)-KERNBASE) 1599335Sdfr 1609335Sdfr#define ALLOCPAGES(foo) \ 1619335Sdfr movl R(physfree), %esi ; \ 16227838Sjdp movl $((foo)*PAGE_SIZE), %eax ; \ 16333137Sjdp addl %esi, %eax ; \ 1649335Sdfr movl %eax, R(physfree) ; \ 1659335Sdfr movl %esi, %edi ; \ 166697Spaul movl $((foo)*PAGE_SIZE),%ecx ; \ 1679335Sdfr xorl %eax,%eax ; \ 1689335Sdfr cld ; \ 169697Spaul rep ; \ 170697Spaul stosb 17193032Simp 17293032Simp/* 17393032Simp * fillkpt 17493032Simp * eax = page frame address 17593032Simp * ebx = index into page table 17693032Simp * ecx = how many pages to map 17793032Simp * base = base address of page dir/table 178697Spaul * prot = protection bits 179697Spaul */ 180697Spaul#define fillkpt(base, prot) \ 181697Spaul shll $2,%ebx ; \ 182697Spaul addl base,%ebx ; \ 183697Spaul orl $PG_V,%eax ; \ 184697Spaul orl prot,%eax ; \ 1851156Sjkh1: movl %eax,(%ebx) ; \ 1861156Sjkh addl $PAGE_SIZE,%eax ; /* increment physical address */ \ 187697Spaul addl $4,%ebx ; /* next pte */ \ 188697Spaul loop 1b 189697Spaul 190697Spaul/* 191697Spaul * fillkptphys(prot) 19283047Sobrien * eax = physical address 1931156Sjkh * ecx = how many pages to map 1941156Sjkh * prot = protection bits 195697Spaul */ 1961156Sjkh#define fillkptphys(prot) \ 1971156Sjkh movl %eax, %ebx ; \ 1986887Snate shrl $PAGE_SHIFT, %ebx ; \ 199697Spaul fillkpt(R(_KPTphys), prot) 200697Spaul 201697Spaul .text 202697Spaul/********************************************************************** 203697Spaul * 204697Spaul * This is where the bootblocks start us, set the ball rolling... 2051156Sjkh * 2061156Sjkh */ 2071156SjkhNON_GPROF_ENTRY(btext) 2081156Sjkh 2091156Sjkh#ifdef PC98 2101156Sjkh /* save SYSTEM PARAMETER for resume (NS/T or other) */ 2111156Sjkh movl $0xa1400,%esi 2121156Sjkh movl $R(_pc98_system_parameter),%edi 21318591Speter movl $0x0240,%ecx 214697Spaul cld 2151156Sjkh rep 2161156Sjkh movsb 2171156Sjkh#else /* IBM-PC */ 2181156Sjkh#ifdef BDE_DEBUGGER 2191156Sjkh#ifdef BIOS_STEALS_3K 2201156Sjkh cmpl $0x0375c339,0x95504 2211156Sjkh#else 222697Spaul cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 223697Spaul#endif 2241156Sjkh jne 1f 225697Spaul movb $1,R(_bdb_exists) 226697Spaul1: 227697Spaul#endif 22813771Smpp#endif /* PC98 */ 229697Spaul 2301156Sjkh/* Tell the bios to warmboot next time */ 231697Spaul movw $0x1234,0x472 232697Spaul 2336887Snate/* Set up a real frame in case the double return in newboot is executed. */ 2346887Snate pushl %ebp 2356887Snate movl %esp, %ebp 23633137Sjdp 237697Spaul/* Don't trust what the BIOS gives for eflags. */ 238697Spaul pushl $PSL_KERNEL 239697Spaul popfl 240697Spaul 241697Spaul/* 242697Spaul * Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap 2431156Sjkh * to set %cs, %ds, %es and %ss. 2441156Sjkh */ 2456887Snate mov %ds, %ax 24633137Sjdp mov %ax, %fs 247697Spaul mov %ax, %gs 248697Spaul 249697Spaul call recover_bootinfo 250697Spaul 251697Spaul/* Get onto a stack that we can trust. */ 252697Spaul/* 253697Spaul * XXX this step is delayed in case recover_bootinfo needs to return via 254697Spaul * the old stack, but it need not be, since recover_bootinfo actually 255697Spaul * returns via the old frame. 256697Spaul */ 257697Spaul movl $R(HIDENAME(tmpstk)),%esp 258697Spaul 259697Spaul#ifdef PC98 260697Spaul /* pc98_machine_type & M_EPSON_PC98 */ 26118591Speter testb $0x02,R(_pc98_system_parameter)+220 262697Spaul jz 3f 263697Spaul /* epson_machine_id <= 0x0b */ 264697Spaul cmpb $0x0b,R(_pc98_system_parameter)+224 265697Spaul ja 3f 266697Spaul 26718591Speter /* count up memory */ 268697Spaul movl $0x100000,%eax /* next, talley remaining memory */ 269697Spaul movl $0xFFF-0x100,%ecx 270697Spaul1: movl 0(%eax),%ebx /* save location to check */ 271697Spaul movl $0xa55a5aa5,0(%eax) /* write test pattern */ 272697Spaul cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */ 273697Spaul jne 2f 274697Spaul movl %ebx,0(%eax) /* restore memory */ 275697Spaul addl $PAGE_SIZE,%eax 276697Spaul loop 1b 277697Spaul2: subl $0x100000,%eax 278697Spaul shrl $17,%eax 279697Spaul movb %al,R(_pc98_system_parameter)+1 280697Spaul3: 281697Spaul#endif 282697Spaul 283697Spaul call identify_cpu 284697Spaul 285697Spaul/* clear bss */ 286697Spaul/* 287697Spaul * XXX this should be done a little earlier. 288102284Speter * 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 .globl __ucodesel,__udatasel 365 366 pushl $0 /* unused */ 367 pushl __udatasel /* ss */ 368 pushl $0 /* esp - filled in by execve() */ 369 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 370 pushl __ucodesel /* cs */ 371 pushl $0 /* eip - filled in by execve() */ 372 subl $(13*4),%esp /* space for rest of registers */ 373 374 pushl %esp /* call main with frame pointer */ 375 call _mi_startup /* autoconfiguration, mountroot etc */ 376 377 hlt /* never returns to here */ 378 379/* 380 * When starting init, call this to configure the process for user 381 * mode. This will be inherited by other processes. 382 */ 383NON_GPROF_ENTRY(prepare_usermode) 384 /* 385 * Now we've run main() and determined what cpu-type we are, we can 386 * enable write protection and alignment checking on i486 cpus and 387 * above. 388 */ 389#if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU) 390 cmpl $CPUCLASS_386,_cpu_class 391 je 1f 392 movl %cr0,%eax /* get control word */ 393 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 394 movl %eax,%cr0 /* and do it */ 3951: 396#endif 397 /* 398 * on return from main(), we are process 1 399 * set up address space and stack so that we can 'return' to user mode 400 */ 401 movl __ucodesel,%eax 402 movl __udatasel,%ecx 403 404#if 0 /* ds/es/fs are in trap frame */ 405 movl %cx,%ds 406 movl %cx,%es 407 movl %cx,%fs 408#endif 409 movl %cx,%gs /* and ds to gs */ 410 ret /* goto user! */ 411 412 413/* 414 * Signal trampoline, copied to top of user stack 415 */ 416NON_GPROF_ENTRY(sigcode) 417 call SIGF_HANDLER(%esp) /* call signal handler */ 418 lea SIGF_UC(%esp),%eax /* get ucontext_t */ 419 pushl %eax 420 testl $PSL_VM,UC_EFLAGS(%eax) 421 jne 9f 422 movl UC_GS(%eax),%gs /* restore %gs */ 4239: 424 movl $SYS_sigreturn,%eax 425 pushl %eax /* junk to fake return addr. */ 426 int $0x80 /* enter kernel with args */ 4270: jmp 0b 428 429 ALIGN_TEXT 430_osigcode: 431 call SIGF_HANDLER(%esp) /* call signal handler */ 432 lea SIGF_SC(%esp),%eax /* get sigcontext */ 433 pushl %eax 434 testl $PSL_VM,SC_PS(%eax) 435 jne 9f 436 movl SC_GS(%eax),%gs /* restore %gs */ 4379: 438 movl $0x01d516,SC_TRAPNO(%eax) /* magic: 0ldSiG */ 439 movl $SYS_sigreturn,%eax 440 pushl %eax /* junk to fake return addr. */ 441 int $0x80 /* enter kernel with args */ 4420: jmp 0b 443 444 ALIGN_TEXT 445_esigcode: 446 447 .data 448 .globl _szsigcode, _szosigcode 449_szsigcode: 450 .long _esigcode-_sigcode 451_szosigcode: 452 .long _esigcode-_osigcode 453 .text 454 455/********************************************************************** 456 * 457 * Recover the bootinfo passed to us from the boot program 458 * 459 */ 460recover_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 */ 518newboot: 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 5311: 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 5451: 546 cld 547 rep 548 movsb 549 5502: 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 561got_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 571got_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 */ 600olddiskboot: 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 */ 614identify_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 645trynexgen: 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 654try486: /* 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 689trycyrix: 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 702trycpuid: /* 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 7231: 724 /* a Pentium? */ 725 cmpl $5,%eax 726 jne 2f 727 movl $CPU_586,R(_cpu) 728 jmp 3f 7292: 730 /* Greater than Pentium...call it a Pentium Pro */ 731 movl $CPU_686,R(_cpu) 7323: 733 ret 734 735 736/********************************************************************** 737 * 738 * Create the first page directory and its page tables. 739 * 740 */ 741 742create_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 7491: 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) 763over_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 771no_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 ALLOCPAGES(1) /* vm86/bios stack */ 793 movl %esi,R(vm86phystk) 794 795 ALLOCPAGES(3) /* pgtable + ext + IOPAGES */ 796 movl %esi,R(_vm86pa) 797 addl $KERNBASE, %esi 798 movl %esi, R(_vm86paddr) 799 800#ifdef SMP 801/* Allocate cpu0's private data page */ 802 ALLOCPAGES(1) 803 movl %esi,R(cpu0pp) 804 addl $KERNBASE, %esi 805 movl %esi, R(_cpu0prvpage) /* relocated to KVM space */ 806 807/* Allocate SMP page table page */ 808 ALLOCPAGES(1) 809 movl %esi,R(SMPptpa) 810 addl $KERNBASE, %esi 811 movl %esi, R(_SMPpt) /* relocated to KVM space */ 812#endif /* SMP */ 813 814/* Map read-only from zero to the end of the kernel text section */ 815 xorl %eax, %eax 816#ifdef BDE_DEBUGGER 817/* If the debugger is present, actually map everything read-write. */ 818 cmpl $0,R(_bdb_exists) 819 jne map_read_write 820#endif 821 xorl %edx,%edx 822 823#if !defined(SMP) 824 testl $CPUID_PGE, R(_cpu_feature) 825 jz 2f 826 orl $PG_G,%edx 827#endif 828 8292: movl $R(_etext),%ecx 830 addl $PAGE_MASK,%ecx 831 shrl $PAGE_SHIFT,%ecx 832 fillkptphys(%edx) 833 834/* Map read-write, data, bss and symbols */ 835 movl $R(_etext),%eax 836 addl $PAGE_MASK, %eax 837 andl $~PAGE_MASK, %eax 838map_read_write: 839 movl $PG_RW,%edx 840#if !defined(SMP) 841 testl $CPUID_PGE, R(_cpu_feature) 842 jz 1f 843 orl $PG_G,%edx 844#endif 845 8461: movl R(_KERNend),%ecx 847 subl %eax,%ecx 848 shrl $PAGE_SHIFT,%ecx 849 fillkptphys(%edx) 850 851/* Map page directory. */ 852 movl R(_IdlePTD), %eax 853 movl $1, %ecx 854 fillkptphys($PG_RW) 855 856/* Map proc0's UPAGES in the physical way ... */ 857 movl R(p0upa), %eax 858 movl $UPAGES, %ecx 859 fillkptphys($PG_RW) 860 861/* Map ISA hole */ 862 movl $ISA_HOLE_START, %eax 863 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 864 fillkptphys($PG_RW) 865 866/* Map space for the vm86 region */ 867 movl R(vm86phystk), %eax 868 movl $4, %ecx 869 fillkptphys($PG_RW) 870 871/* Map page 0 into the vm86 page table */ 872 movl $0, %eax 873 movl $0, %ebx 874 movl $1, %ecx 875 fillkpt(R(_vm86pa), $PG_RW|PG_U) 876 877/* ...likewise for the ISA hole */ 878 movl $ISA_HOLE_START, %eax 879 movl $ISA_HOLE_START>>PAGE_SHIFT, %ebx 880 movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx 881 fillkpt(R(_vm86pa), $PG_RW|PG_U) 882 883#ifdef SMP 884/* Map cpu0's private page into global kmem (4K @ cpu0prvpage) */ 885 movl R(cpu0pp), %eax 886 movl $1, %ecx 887 fillkptphys($PG_RW) 888 889/* Map SMP page table page into global kmem FWIW */ 890 movl R(SMPptpa), %eax 891 movl $1, %ecx 892 fillkptphys($PG_RW) 893 894/* Map the private page into the SMP page table */ 895 movl R(cpu0pp), %eax 896 movl $0, %ebx /* pte offset = 0 */ 897 movl $1, %ecx /* one private page coming right up */ 898 fillkpt(R(SMPptpa), $PG_RW) 899 900/* ... and put the page table table in the pde. */ 901 movl R(SMPptpa), %eax 902 movl $MPPTDI, %ebx 903 movl $1, %ecx 904 fillkpt(R(_IdlePTD), $PG_RW) 905 906/* Fakeup VA for the local apic to allow early traps. */ 907 ALLOCPAGES(1) 908 movl %esi, %eax 909 movl $(NPTEPG-1), %ebx /* pte offset = NTEPG-1 */ 910 movl $1, %ecx /* one private pt coming right up */ 911 fillkpt(R(SMPptpa), $PG_RW) 912 913/* Initialize mp lock to allow early traps */ 914 movl $1, R(_mp_lock) 915#endif /* SMP */ 916 917/* install a pde for temporary double map of bottom of VA */ 918 movl R(_KPTphys), %eax 919 xorl %ebx, %ebx 920 movl $1, %ecx 921 fillkpt(R(_IdlePTD), $PG_RW) 922 923/* install pde's for pt's */ 924 movl R(_KPTphys), %eax 925 movl $KPTDI, %ebx 926 movl $NKPT, %ecx 927 fillkpt(R(_IdlePTD), $PG_RW) 928 929/* install a pde recursively mapping page directory as a page table */ 930 movl R(_IdlePTD), %eax 931 movl $PTDPTDI, %ebx 932 movl $1,%ecx 933 fillkpt(R(_IdlePTD), $PG_RW) 934 935 ret 936 937#ifdef BDE_DEBUGGER 938bdb_prepare_paging: 939 cmpl $0,R(_bdb_exists) 940 je bdb_prepare_paging_exit 941 942 subl $6,%esp 943 944 /* 945 * Copy and convert debugger entries from the bootstrap gdt and idt 946 * to the kernel gdt and idt. Everything is still in low memory. 947 * Tracing continues to work after paging is enabled because the 948 * low memory addresses remain valid until everything is relocated. 949 * However, tracing through the setidt() that initializes the trace 950 * trap will crash. 951 */ 952 sgdt (%esp) 953 movl 2(%esp),%esi /* base address of bootstrap gdt */ 954 movl $R(_gdt),%edi 955 movl %edi,2(%esp) /* prepare to load kernel gdt */ 956 movl $8*18/4,%ecx 957 cld 958 rep /* copy gdt */ 959 movsl 960 movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */ 961 movb $0x92,-8+5(%edi) 962 lgdt (%esp) 963 964 sidt (%esp) 965 movl 2(%esp),%esi /* base address of current idt */ 966 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 967 movw 8(%esi),%ax 968 movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */ 969 movl 8+2(%esi),%eax 970 movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */ 971 movl 24+4(%esi),%eax /* same for bpt descriptor */ 972 movw 24(%esi),%ax 973 movl %eax,R(bdb_bpt_ljmp+1) 974 movl 24+2(%esi),%eax 975 movw %ax,R(bdb_bpt_ljmp+5) 976 movl R(_idt),%edi 977 movl %edi,2(%esp) /* prepare to load kernel idt */ 978 movl $8*4/4,%ecx 979 cld 980 rep /* copy idt */ 981 movsl 982 lidt (%esp) 983 984 addl $6,%esp 985 986bdb_prepare_paging_exit: 987 ret 988 989/* Relocate debugger gdt entries and gdt and idt pointers. */ 990bdb_commit_paging: 991 cmpl $0,_bdb_exists 992 je bdb_commit_paging_exit 993 994 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 995 movl $9,%ecx 996reloc_gdt: 997 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 998 addl $8,%eax /* now KERNBASE>>24 */ 999 loop reloc_gdt 1000 1001 subl $6,%esp 1002 sgdt (%esp) 1003 addl $KERNBASE,2(%esp) 1004 lgdt (%esp) 1005 sidt (%esp) 1006 addl $KERNBASE,2(%esp) 1007 lidt (%esp) 1008 addl $6,%esp 1009 1010 int $3 1011 1012bdb_commit_paging_exit: 1013 ret 1014 1015#endif /* BDE_DEBUGGER */ 1016