locore.s revision 5908
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 * $Id: locore.s,v 1.46 1995/01/14 13:20:07 bde Exp $ 38 */ 39 40/* 41 * locore.s: FreeBSD machine support for the Intel 386 42 * originally from: locore.s, by William F. Jolitz 43 * 44 * Substantially rewritten by David Greenman, Rod Grimes, 45 * Bruce Evans, Wolfgang Solfrank, and many others. 46 */ 47 48#include "assym.s" /* system definitions */ 49#include <machine/psl.h> /* processor status longword defs */ 50#include <machine/pte.h> /* page table entry definitions */ 51#include <sys/errno.h> /* error return codes */ 52#include <machine/specialreg.h> /* x86 special registers */ 53#include <machine/cputypes.h> /* x86 cpu type definitions */ 54#include <sys/syscall.h> /* system call numbers */ 55#include <machine/asmacros.h> /* miscellaneous asm macros */ 56#include <sys/reboot.h> 57#include "apm.h" 58#if NAPM > 0 59#define ASM 60#include <machine/apm_bios.h> 61#include <machine/apm_segments.h> 62#endif /* NAPM */ 63 64/* 65 * XXX 66 * 67 * Note: This version greatly munged to avoid various assembler errors 68 * that may be fixed in newer versions of gas. Perhaps newer versions 69 * will have more pleasant appearance. 70 */ 71 72/* 73 * PTmap is recursive pagemap at top of virtual address space. 74 * Within PTmap, the page directory can be found (third indirection). 75 */ 76 .globl _PTmap,_PTD,_PTDpde 77 .set _PTmap,PTDPTDI << PDRSHIFT 78 .set _PTD,_PTmap + (PTDPTDI * NBPG) 79 .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 80 81/* 82 * Sysmap is the base address of the kernel page tables. 83 * It is a bogus interface for kgdb and isn't used by the kernel itself. 84 */ 85 .set _Sysmap,_PTmap + (KPTDI * NBPG) 86 87/* 88 * APTmap, APTD is the alternate recursive pagemap. 89 * It's used when modifying another process's page tables. 90 */ 91 .globl _APTmap,_APTD,_APTDpde 92 .set _APTmap,APTDPTDI << PDRSHIFT 93 .set _APTD,_APTmap + (APTDPTDI * NBPG) 94 .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 95 96/* 97 * Access to each processes kernel stack is via a region of 98 * per-process address space (at the beginning), immediatly above 99 * the user process stack. 100 */ 101 .set _kstack,USRSTACK 102 .globl _kstack 103 104/* 105 * Globals 106 */ 107 .data 108 109 .globl tmpstk 110 .space 0x1000 /* space for tmpstk - temporary stack */ 111tmpstk: 112/* 113 * Dummy frame at top of tmpstk to help debuggers print a nice stack trace. 114 */ 115 .long tmpstk+8 /* caller's %ebp */ 116 .long _cpu_switch /* caller */ 117 .long 0 /* %ebp == 0 should terminate trace */ 118 .long _mvesp /* in case %ebp == 0 doesn't work ... */ 119 .long 0x11111111, 0x22222222, 0x33333333, 0x44444444, 0x55555555 120 121 .globl _boothowto,_bootdev 122 123 .globl _cpu,_cold,_atdevbase,_cpu_vendor,_cpu_id,_bootinfo 124 125_cpu: .long 0 /* are we 386, 386sx, or 486 */ 126_cpu_id: .long 0 /* stepping ID */ 127_cpu_vendor: .space 20 /* CPU origin code */ 128_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */ 129_cold: .long 1 /* cold till we are not */ 130_atdevbase: .long 0 /* location of start of iomem in virtual */ 131_atdevphys: .long 0 /* location of device mapping ptes (phys) */ 132 133_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 134 135 .globl _IdlePTD 136_IdlePTD: .long 0 /* phys addr of kernel PTD */ 137 138_KPTphys: .long 0 /* phys addr of kernel page tables */ 139 140 .globl _proc0paddr 141_proc0paddr: .long 0 /* address of proc 0 address space */ 142 143#ifdef BDE_DEBUGGER 144 .globl _bdb_exists /* flag to indicate BDE debugger is available */ 145_bdb_exists: .long 0 146#endif 147#if NAPM > 0 148 .globl _apm_current_gdt_pdesc /* current GDT pseudo desc. */ 149_apm_current_gdt_pdesc: 150 .word 0, 0, 0 151 152 .globl _bootstrap_gdt 153_bootstrap_gdt: 154 .space SIZEOF_GDT * BOOTSTRAP_GDT_NUM 155#endif /* NAPM */ 156 157/* 158 * System Initialization 159 */ 160 .text 161 162/* 163 * btext: beginning of text section. 164 * Also the entry point (jumped to directly from the boot blocks). 165 */ 166NON_GPROF_ENTRY(btext) 167 movw $0x1234,0x472 /* warm boot */ 168 jmp 1f 169 /* 170 * XXX now that we load at 1MB is this still really used? 171 */ 172 .org 0x500 /* space for BIOS variables */ 173 1741: 175 /* Set up a real frame, some day we will be doing returns */ 176 pushl %ebp 177 movl %esp, %ebp 178 179 /* Don't trust what the BIOS gives for eflags. */ 180 pushl $PSL_KERNEL 181 popfl 182 183 /* Don't trust what the BIOS gives for %fs and %gs. */ 184 mov %ds, %ax 185 mov %ax, %fs 186 mov %ax, %gs 187 188 /* 189 * This code is called in different ways depending on what loaded 190 * and started the kernel. This is used to detect how we get the 191 * arguments from the other code and what we do with them. 192 * 193 * Old disk boot blocks: 194 * (*btext)(howto, bootdev, cyloffset, esym); 195 * [return address == 0, and can NOT be returned to] 196 * [cyloffset was not supported by the FreeBSD boot code 197 * and always passed in as 0] 198 * [esym is also known as total in the boot code, and 199 * was never properly supported by the FreeBSD boot code] 200 * 201 * Old diskless netboot code: 202 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 203 * [return address != 0, and can NOT be returned to] 204 * If we are being booted by this code it will NOT work, 205 * so we are just going to halt if we find this case. 206 * 207 * New uniform boot code: 208 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 209 * [return address != 0, and can be returned to] 210 * 211 * There may seem to be a lot of wasted arguments in here, but 212 * that is so the newer boot code can still load very old kernels 213 * and old boot code can load new kernels. 214 */ 215 216 /* 217 * The old style disk boot blocks fake a frame on the stack and 218 * did an lret to get here. The frame on the stack has a return 219 * address of 0. 220 */ 221 cmpl $0,4(%ebp) 222 je 2f /* olddiskboot: */ 223 224 /* 225 * We have some form of return address, so this is either the 226 * old diskless netboot code, or the new uniform code. That can 227 * be detected by looking at the 5th argument, it if is 0 we 228 * we are being booted by the new unifrom boot code. 229 */ 230 cmpl $0,24(%ebp) 231 je 1f /* newboot: */ 232 233 /* 234 * Seems we have been loaded by the old diskless boot code, we 235 * don't stand a chance of running as the diskless structure 236 * changed considerably between the two, so just halt. 237 */ 238 hlt 239 240 /* 241 * We have been loaded by the new uniform boot code. 242 * Lets check the bootinfo version, and if we do not understand 243 * it we return to the loader with a status of 1 to indicate this error 244 */ 2451: /* newboot: */ 246 movl 28(%ebp),%ebx /* &bootinfo.version */ 247 movl BI_VERSION(%ebx),%eax 248 cmpl $1,%eax /* We only understand version 1 */ 249 je 1f 250 movl $1,%eax /* Return status */ 251 leave 252 ret 253 2541: 255 /* 256 * If we have a kernelname copy it in 257 */ 258 movl BI_KERNELNAME(%ebx),%esi 259 cmpl $0,%esi 260 je 1f /* No kernelname */ 261 lea _kernelname-KERNBASE,%edi 262 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 263 cld 264 rep 265 movsb 266 2671: 268 /* 269 * Determine the size of the boot loader's copy of the bootinfo 270 * struct. This is impossible to do properly because old versions 271 * of the struct don't contain a size field and there are 2 old 272 * versions with the same version number. 273 */ 274 movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */ 275 testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */ 276 je got_bi_size /* no, sizeless version */ 277 movl BI_SIZE(%ebx),%ecx 278got_bi_size: 279 280 /* 281 * Copy the common part of the bootinfo struct 282 */ 283 movl %ebx,%esi 284 movl $_bootinfo-KERNBASE,%edi 285 cmpl $BOOTINFO_SIZE,%ecx 286 jbe got_common_bi_size 287 movl $BOOTINFO_SIZE,%ecx 288got_common_bi_size: 289 cld 290 rep 291 movsb 292 293#ifdef NFS 294 /* 295 * If we have a nfs_diskless structure copy it in 296 */ 297 movl BI_NFS_DISKLESS(%ebx),%esi 298 cmpl $0,%esi 299 je 2f 300 lea _nfs_diskless-KERNBASE,%edi 301 movl $NFSDISKLESS_SIZE,%ecx 302 cld 303 rep 304 movsb 305 lea _nfs_diskless_valid-KERNBASE,%edi 306 movl $1,(%edi) 307#endif 308 309 /* 310 * The old style disk boot. 311 * (*btext)(howto, bootdev, cyloffset, esym); 312 * Note that the newer boot code just falls into here to pick 313 * up howto and bootdev, cyloffset and esym are no longer used 314 */ 3152: /* olddiskboot: */ 316 movl 8(%ebp),%eax 317 movl %eax,_boothowto-KERNBASE 318 movl 12(%ebp),%eax 319 movl %eax,_bootdev-KERNBASE 320 321#if NAPM > 0 322 /* 323 * Setup APM BIOS: 324 * 325 * APM BIOS initialization should be done from real mode or V86 mode. 326 * 327 * (by HOSOKAWA, Tatsumi <hosokawa@mt.cs.keio.ac.jp>) 328 */ 329 330 /* 331 * Copy APM initializer under 1MB boundary: 332 * 333 * APM initializer program must switch the CPU to real mode. 334 * But FreeBSD kernel runs above 1MB boundary. So we must 335 * copy the initializer code to conventional memory. 336 */ 337 movl _apm_init_image_size-KERNBASE, %ecx /* size */ 338 lea _apm_init_image-KERNBASE, %esi /* source */ 339 movl $ APM_OURADDR, %edi /* destination */ 340 cld 341 rep 342 movsb 343 344 /* get GDT base */ 345 sgdt _apm_current_gdt_pdesc-KERNBASE 346 347 /* copy GDT to _bootstrap_gdt */ 348 xorl %ecx, %ecx 349 movw _apm_current_gdt_pdesc-KERNBASE, %cx 350 movl _apm_current_gdt_pdesc-KERNBASE+2, %esi 351 lea _bootstrap_gdt-KERNBASE, %edi 352 cld 353 rep 354 movsb 355 356 /* setup GDT pseudo descriptor */ 357 movw $(SIZEOF_GDT*BOOTSTRAP_GDT_NUM), %ax 358 movw %ax, _apm_current_gdt_pdesc-KERNBASE 359 leal _bootstrap_gdt-KERNBASE, %eax 360 movl %eax, _apm_current_gdt_pdesc-KERNBASE+2 361 362 /* load new GDTR */ 363 lgdt _apm_current_gdt_pdesc-KERNBASE 364 365 /* setup GDT for APM initializer */ 366 lea _bootstrap_gdt-KERNBASE, %ecx 367 movl $(APM_OURADDR), %eax /* use %ax for 15..0 */ 368 movl %eax, %ebx 369 shrl $16, %ebx /* use %bl for 23..16 */ 370 /* use %bh for 31..24 */ 371#define APM_SETUP_GDT(index, attrib) \ 372 movl $(index), %si ; \ 373 lea 0(%ecx,%esi,8), %edx ; \ 374 movw $0xffff, (%edx) ; \ 375 movw %ax, 2(%edx) ; \ 376 movb %bl, 4(%edx) ; \ 377 movw $(attrib), 5(%edx) ; \ 378 movb %bh, 7(%edx) 379 380 APM_SETUP_GDT(APM_INIT_CS_INDEX , CS32_ATTRIB) 381 APM_SETUP_GDT(APM_INIT_DS_INDEX , DS32_ATTRIB) 382 APM_SETUP_GDT(APM_INIT_CS16_INDEX, CS16_ATTRIB) 383 384 /* 385 * Call the initializer: 386 * 387 * direct intersegment call to conventional memory code 388 */ 389 .byte 0x9a /* actually, lcall $APM_INIT_CS_SEL, $0 */ 390 .long 0 391 .word APM_INIT_CS_SEL 392 393 movw %ax, _apm_version-KERNBASE 394 movl %ebx, _apm_cs_entry-KERNBASE 395 movw %cx, _apm_cs32_base-KERNBASE 396 shrl $16, %ecx 397 movw %cx, _apm_cs16_base-KERNBASE 398 movw %dx, _apm_ds_base-KERNBASE 399 movw %si, _apm_cs_limit-KERNBASE 400 shrl $16, %esi 401 movw %si, _apm_ds_limit-KERNBASE 402 movw %di, _apm_flags-KERNBASE 403#endif /* NAPM */ 404 405 /* Find out our CPU type. */ 406 407 /* Try to toggle alignment check flag; does not exist on 386. */ 408 pushfl 409 popl %eax 410 movl %eax,%ecx 411 orl $PSL_AC,%eax 412 pushl %eax 413 popfl 414 pushfl 415 popl %eax 416 xorl %ecx,%eax 417 andl $PSL_AC,%eax 418 pushl %ecx 419 popfl 420 421 testl %eax,%eax 422 jnz 1f 423 movl $CPU_386,_cpu-KERNBASE 424 jmp 2f 425 4261: /* Try to toggle identification flag; does not exist on early 486s. */ 427 pushfl 428 popl %eax 429 movl %eax,%ecx 430 xorl $PSL_ID,%eax 431 pushl %eax 432 popfl 433 pushfl 434 popl %eax 435 xorl %ecx,%eax 436 andl $PSL_ID,%eax 437 pushl %ecx 438 popfl 439 440 testl %eax,%eax 441 jnz 1f 442 movl $CPU_486,_cpu-KERNBASE 443 444 /* check for Cyrix 486DLC -- based on check routine */ 445 /* documented in "Cx486SLC/e SMM Programmer's Guide" */ 446 xorw %dx,%dx 447 cmpw %dx,%dx # set flags to known state 448 pushfw 449 popw %cx # store flags in ecx 450 movw $0xffff,%ax 451 movw $0x0004,%bx 452 divw %bx 453 pushfw 454 popw %ax 455 andw $0x08d5,%ax # mask off important bits 456 andw $0x08d5,%cx 457 cmpw %ax,%cx 458 459 jnz 2f # if flags changed, Intel chip 460 461 movl $CPU_486DLC,_cpu-KERNBASE # set CPU value for Cyrix 462 movl $0x69727943,_cpu_vendor-KERNBASE # store vendor string 463 movw $0x0078,_cpu_vendor-KERNBASE+4 464 465 invd # Start with guaranteed clean cache 466 /* Disable caching of the ISA hole only. */ 467 movb $CCR0,%al # Configuration Register index (CCR0) 468 outb %al,$0x22 469 inb $0x23,%al 470 orb $(CCR0_NC1|CCR0_BARB),%al 471 outb %al,$0x23 472 invd 473 jmp 2f 474 4751: /* Use the `cpuid' instruction. */ 476 xorl %eax,%eax 477 .byte 0x0f,0xa2 # cpuid 0 478 movl %ebx,_cpu_vendor-KERNBASE # store vendor string 479 movl %edx,_cpu_vendor+4-KERNBASE 480 movl %ecx,_cpu_vendor+8-KERNBASE 481 movb $0,_cpu_vendor+12-KERNBASE 482 483 movl $1,%eax 484 .byte 0x0f,0xa2 # cpuid 1 485 movl %eax,_cpu_id-KERNBASE # store cpu_id 486 rorl $8,%eax # extract family type 487 andl $15,%eax 488 cmpl $5,%eax 489 jae 1f 490 491 /* less than Pentium; must be 486 */ 492 movl $CPU_486,_cpu-KERNBASE 493 jmp 2f 494 4951: movl $CPU_586,_cpu-KERNBASE 4962: 497 498 /* 499 * Finished with old stack; load new %esp now instead of later so 500 * we can trace this code without having to worry about the trace 501 * trap clobbering the memory test or the zeroing of the bss+bootstrap 502 * page tables. 503 * 504 * XXX - wdboot clears the bss after testing that this is safe. 505 * This is too wasteful - memory below 640K is scarce. The boot 506 * program should check: 507 * text+data <= &stack_variable - more_space_for_stack 508 * text+data+bss+pad+space_for_page_tables <= end_of_memory 509 * Oops, the gdt is in the carcass of the boot program so clearing 510 * the rest of memory is still not possible. 511 */ 512 movl $tmpstk-KERNBASE,%esp /* bootstrap stack end location */ 513 514/* 515 * Virtual address space of kernel: 516 * 517 * text | data | bss | [syms] | page dir | proc0 kernel stack | usr stk map | Sysmap 518 * pages: 1 UPAGES (2) 1 NKPT (7) 519 */ 520 521/* find end of kernel image */ 522 movl $_end-KERNBASE,%ecx 523 addl $NBPG-1,%ecx /* page align up */ 524 andl $~(NBPG-1),%ecx 525 movl %ecx,%esi /* esi = start of free memory */ 526 movl %ecx,_KERNend-KERNBASE /* save end of kernel */ 527 528/* clear bss */ 529 movl $_edata-KERNBASE,%edi 530 subl %edi,%ecx /* get amount to clear */ 531 xorl %eax,%eax /* specify zero fill */ 532 cld 533 rep 534 stosb 535 536#ifdef DDB 537/* include symbols in "kernel image" if they are loaded */ 538 movl _bootinfo+BI_ESYMTAB-KERNBASE,%edi 539 testl %edi,%edi 540 je over_symalloc 541 addl $NBPG-1,%edi 542 andl $~(NBPG-1),%edi 543 movl %edi,%esi 544 movl %esi,_KERNend-KERNBASE 545 movl $KERNBASE,%edi 546 addl %edi,_bootinfo+BI_SYMTAB-KERNBASE 547 addl %edi,_bootinfo+BI_ESYMTAB-KERNBASE 548over_symalloc: 549#endif 550 551/* 552 * The value in esi is both the end of the kernel bss and a pointer to 553 * the kernel page directory, and is used by the rest of locore to build 554 * the tables. 555 * esi + 1(page dir) + 2(UPAGES) + 1(p0stack) + NKPT(number of kernel 556 * page table pages) is then passed on the stack to init386(first) as 557 * the value first. esi should ALWAYS be page aligned!! 558 */ 559 movl %esi,%ecx /* Get current first availiable address */ 560 561/* clear pagetables, page directory, stack, etc... */ 562 movl %esi,%edi /* base (page directory) */ 563 movl $((1+UPAGES+1+NKPT)*NBPG),%ecx /* amount to clear */ 564 xorl %eax,%eax /* specify zero fill */ 565 cld 566 rep 567 stosb 568 569/* physical address of Idle proc/kernel page directory */ 570 movl %esi,_IdlePTD-KERNBASE 571 572/* 573 * fillkpt 574 * eax = (page frame address | control | status) == pte 575 * ebx = address of page table 576 * ecx = how many pages to map 577 */ 578#define fillkpt \ 5791: movl %eax,(%ebx) ; \ 580 addl $NBPG,%eax ; /* increment physical address */ \ 581 addl $4,%ebx ; /* next pte */ \ 582 loop 1b ; 583 584/* 585 * Map Kernel 586 * 587 * First step - build page tables 588 */ 589#if defined (KGDB) || defined (BDE_DEBUGGER) 590 movl _KERNend-KERNBASE,%ecx /* this much memory, */ 591 shrl $PGSHIFT,%ecx /* for this many PTEs */ 592#ifdef BDE_DEBUGGER 593 cmpl $0xa0,%ecx /* XXX - cover debugger pages */ 594 jae 1f 595 movl $0xa0,%ecx 5961: 597#endif /* BDE_DEBUGGER */ 598 movl $PG_V|PG_KW,%eax /* kernel R/W, valid */ 599 lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 600 movl %ebx,_KPTphys-KERNBASE /* save in global */ 601 fillkpt 602 603#else /* !KGDB && !BDE_DEBUGGER */ 604 /* write protect kernel text (doesn't do a thing for 386's - only 486's) */ 605 movl $_etext-KERNBASE,%ecx /* get size of text */ 606 addl $NBPG-1,%ecx /* round up to page */ 607 shrl $PGSHIFT,%ecx /* for this many PTEs */ 608 movl $PG_V|PG_KR,%eax /* specify read only */ 609#if 0 610 movl $_etext,%ecx /* get size of text */ 611 subl $_btext,%ecx 612 addl $NBPG-1,%ecx /* round up to page */ 613 shrl $PGSHIFT,%ecx /* for this many PTEs */ 614 movl $_btext-KERNBASE,%eax /* get offset to physical memory */ 615 orl $PG_V|PG_KR,%eax /* specify read only */ 616#endif 617 lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 618 movl %ebx,_KPTphys-KERNBASE /* save in global */ 619 fillkpt 620 621 /* data and bss are r/w */ 622 andl $PG_FRAME,%eax /* strip to just addr of bss */ 623 movl _KERNend-KERNBASE,%ecx /* calculate size */ 624 subl %eax,%ecx 625 shrl $PGSHIFT,%ecx 626 orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 627 fillkpt 628#endif /* KGDB || BDE_DEBUGGER */ 629 630/* now initialize the page dir, upages, p0stack PT, and page tables */ 631 632 movl $(1+UPAGES+1+NKPT),%ecx /* number of PTEs */ 633 movl %esi,%eax /* phys address of PTD */ 634 andl $PG_FRAME,%eax /* convert to PFN, should be a NOP */ 635 orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 636 movl %esi,%ebx /* calculate pte offset to ptd */ 637 shrl $PGSHIFT-2,%ebx 638 addl %esi,%ebx /* address of page directory */ 639 addl $((1+UPAGES+1)*NBPG),%ebx /* offset to kernel page tables */ 640 fillkpt 641 642/* map I/O memory map */ 643 644 movl _KPTphys-KERNBASE,%ebx /* base of kernel page tables */ 645 lea (0xa0 * PTESIZE)(%ebx),%ebx /* hardwire ISA hole at KERNBASE + 0xa0000 */ 646 movl $0x100-0xa0,%ecx /* for this many pte s, */ 647 movl $(0xa0000|PG_V|PG_KW|PG_N),%eax /* valid, kernel read/write, non-cacheable */ 648 movl %ebx,_atdevphys-KERNBASE /* save phys addr of ptes */ 649 fillkpt 650 651 /* map proc 0's kernel stack into user page table page */ 652 653 movl $UPAGES,%ecx /* for this many pte s, */ 654 lea (1*NBPG)(%esi),%eax /* physical address in proc 0 */ 655 lea (KERNBASE)(%eax),%edx /* change into virtual addr */ 656 movl %edx,_proc0paddr-KERNBASE /* save VA for proc 0 init */ 657 orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 658 lea ((1+UPAGES)*NBPG)(%esi),%ebx /* addr of stack page table in proc 0 */ 659 addl $(KSTKPTEOFF * PTESIZE),%ebx /* offset to kernel stack PTE */ 660 fillkpt 661 662/* 663 * Initialize kernel page table directory 664 */ 665 /* install a pde for temporary double map of bottom of VA */ 666 movl _KPTphys-KERNBASE,%eax 667 orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 668 movl %eax,(%esi) /* which is where temp maps! */ 669 670 /* initialize kernel pde's */ 671 movl $(NKPT),%ecx /* for this many PDEs */ 672 lea (KPTDI*PDESIZE)(%esi),%ebx /* offset of pde for kernel */ 673 fillkpt 674 675 /* install a pde recursively mapping page directory as a page table! */ 676 movl %esi,%eax /* phys address of ptd in proc 0 */ 677 orl $PG_V|PG_KW,%eax /* pde entry is valid */ 678 movl %eax,PTDPTDI*PDESIZE(%esi) /* which is where PTmap maps! */ 679 680 /* install a pde to map kernel stack for proc 0 */ 681 lea ((1+UPAGES)*NBPG)(%esi),%eax /* physical address of pt in proc 0 */ 682 orl $PG_V|PG_KW,%eax /* pde entry is valid */ 683 movl %eax,KSTKPTDI*PDESIZE(%esi) /* which is where kernel stack maps! */ 684 685#ifdef BDE_DEBUGGER 686 /* copy and convert stuff from old gdt and idt for debugger */ 687 688 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 689 jne 1f 690 movb $1,_bdb_exists-KERNBASE 6911: 692 pushal 693 subl $2*6,%esp 694 695 sgdt (%esp) 696 movl 2(%esp),%esi /* base address of current gdt */ 697 movl $_gdt-KERNBASE,%edi 698 movl %edi,2(%esp) 699 movl $8*18/4,%ecx 700 cld 701 rep /* copy gdt */ 702 movsl 703 movl $_gdt-KERNBASE,-8+2(%edi) /* adjust gdt self-ptr */ 704 movb $0x92,-8+5(%edi) 705 706 sidt 6(%esp) 707 movl 6+2(%esp),%esi /* base address of current idt */ 708 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 709 movw 8(%esi),%ax 710 movl %eax,bdb_dbg_ljmp+1-KERNBASE /* ... immediate offset ... */ 711 movl 8+2(%esi),%eax 712 movw %ax,bdb_dbg_ljmp+5-KERNBASE /* ... and selector for ljmp */ 713 movl 24+4(%esi),%eax /* same for bpt descriptor */ 714 movw 24(%esi),%ax 715 movl %eax,bdb_bpt_ljmp+1-KERNBASE 716 movl 24+2(%esi),%eax 717 movw %ax,bdb_bpt_ljmp+5-KERNBASE 718 719 movl $_idt-KERNBASE,%edi 720 movl %edi,6+2(%esp) 721 movl $8*4/4,%ecx 722 cld 723 rep /* copy idt */ 724 movsl 725 726 lgdt (%esp) 727 lidt 6(%esp) 728 729 addl $2*6,%esp 730 popal 731#endif /* BDE_DEBUGGER */ 732 733 /* load base of page directory and enable mapping */ 734 movl %esi,%eax /* phys address of ptd in proc 0 */ 735 movl %eax,%cr3 /* load ptd addr into mmu */ 736 movl %cr0,%eax /* get control word */ 737 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 738 movl %eax,%cr0 /* and let's page NOW! */ 739 740 pushl $begin /* jump to high mem */ 741 ret 742 743begin: /* now running relocated at KERNBASE where the system is linked to run */ 744 movl _atdevphys,%edx /* get pte PA */ 745 subl _KPTphys,%edx /* remove base of ptes, now have phys offset */ 746 shll $PGSHIFT-2,%edx /* corresponding to virt offset */ 747 addl $KERNBASE,%edx /* add virtual base */ 748 movl %edx,_atdevbase 749 750#include "sc.h" 751#include "vt.h" 752#if NSC > 0 || NVT > 0 753 /* XXX: can't scinit relocate Crtat relative to atdevbase itself? */ 754 .globl _Crtat /* XXX - locore should not know about */ 755 movl _Crtat,%eax /* variables of device drivers (pccons)! */ 756 subl $(KERNBASE+0xA0000),%eax 757 addl %eax,%edx 758 movl %edx,_Crtat 759#endif 760 761 /* set up bootstrap stack - 48 bytes */ 762 movl $_kstack+UPAGES*NBPG-4*12,%esp /* bootstrap stack end location */ 763 xorl %eax,%eax /* mark end of frames */ 764 movl %eax,%ebp 765 movl _proc0paddr,%eax 766 movl %esi,PCB_CR3(%eax) 767 768#ifdef BDE_DEBUGGER 769 /* relocate debugger gdt entries */ 770 771 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 772 movl $9,%ecx 773reloc_gdt: 774 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 775 addl $8,%eax /* now KERNBASE>>24 */ 776 loop reloc_gdt 777 778 cmpl $0,_bdb_exists 779 je 1f 780 int $3 7811: 782#endif /* BDE_DEBUGGER */ 783 784 /* 785 * Skip over the page tables and the kernel stack 786 */ 787 lea ((1+UPAGES+1+NKPT)*NBPG)(%esi),%esi 788 789 pushl %esi /* value of first for init386(first) */ 790 call _init386 /* wire 386 chip for unix operation */ 791 popl %esi 792 793 .globl __ucodesel,__udatasel 794 795 pushl $0 /* unused */ 796 pushl __udatasel /* ss */ 797 pushl $0 /* esp - filled in by execve() */ 798 pushl $PSL_USER /* eflags (IOPL 0, int enab) */ 799 pushl __ucodesel /* cs */ 800 pushl $0 /* eip - filled in by execve() */ 801 subl $(12*4),%esp /* space for rest of registers */ 802 803 pushl %esp /* call main with frame pointer */ 804 call _main /* autoconfiguration, mountroot etc */ 805 806 addl $(13*4),%esp /* back to a frame we can return with */ 807 808 /* 809 * now we've run main() and determined what cpu-type we are, we can 810 * enable write protection and alignment checking on i486 cpus and 811 * above. 812 */ 813#if defined(I486_CPU) || defined(I586_CPU) 814 cmpl $CPUCLASS_386,_cpu_class 815 je 1f 816 movl %cr0,%eax /* get control word */ 817 orl $CR0_WP|CR0_AM,%eax /* enable i486 features */ 818 movl %eax,%cr0 /* and do it */ 819#endif 820 /* 821 * on return from main(), we are process 1 822 * set up address space and stack so that we can 'return' to user mode 823 */ 8241: 825 movl __ucodesel,%eax 826 movl __udatasel,%ecx 827 828 movl %cx,%ds 829 movl %cx,%es 830 movl %ax,%fs /* double map cs to fs */ 831 movl %cx,%gs /* and ds to gs */ 832 iret /* goto user! */ 833 834#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 835 836NON_GPROF_ENTRY(sigcode) 837 call SIGF_HANDLER(%esp) 838 lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 839 /* copy at 8(%esp)) */ 840 pushl %eax 841 pushl %eax /* junk to fake return address */ 842 movl $103,%eax /* XXX sigreturn() */ 843 LCALL(0x7,0) /* enter kernel with args on stack */ 844 hlt /* never gets here */ 845 846 .globl _szsigcode 847_szsigcode: 848 .long _szsigcode-_sigcode 849