locore.s revision 3795
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 1.37 1994/10/20 00:07:47 phk 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 "npx.h" /* for NNPX */ 49#include "assym.s" /* system definitions */ 50#include <machine/psl.h> /* processor status longword defs */ 51#include <machine/pte.h> /* page table entry definitions */ 52#include <sys/errno.h> /* error return codes */ 53#include <machine/specialreg.h> /* x86 special registers */ 54#include <machine/cputypes.h> /* x86 cpu type definitions */ 55#include <sys/syscall.h> /* system call numbers */ 56#include <machine/asmacros.h> /* miscellaneous asm macros */ 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,_Sysmap 77 .set _PTmap,PTDPTDI << PDRSHIFT 78 .set _PTD,_PTmap + (PTDPTDI * NBPG) 79 .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 80 81/* Sysmap is the base address of the kernel page tables */ 82 .set _Sysmap,_PTmap + (KPTDI * NBPG) 83 84/* 85 * APTmap, APTD is the alternate recursive pagemap. 86 * It's used when modifying another process's page tables. 87 */ 88 .globl _APTmap,_APTD,_APTDpde 89 .set _APTmap,APTDPTDI << PDRSHIFT 90 .set _APTD,_APTmap + (APTDPTDI * NBPG) 91 .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 92 93/* 94 * Access to each processes kernel stack is via a region of 95 * per-process address space (at the beginning), immediatly above 96 * the user process stack. 97 */ 98 .set _kstack,USRSTACK 99 .globl _kstack 100 101/* 102 * Globals 103 */ 104 .data 105 106 .globl _boothowto,_bootdev,_curpcb 107 108 .globl _cpu,_cold,_atdevbase,_cpu_vendor,_cpu_id 109 110 .globl _video_mode_ptr 111 112_cpu: .long 0 /* are we 386, 386sx, or 486 */ 113_cpu_id: .long 0 /* stepping ID */ 114_cpu_vendor: .space 20 /* CPU origin code */ 115_video_mode_ptr: .long 0 116_cold: .long 1 /* cold till we are not */ 117_atdevbase: .long 0 /* location of start of iomem in virtual */ 118_atdevphys: .long 0 /* location of device mapping ptes (phys) */ 119 120 .globl _KERNend 121_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 122 123 .globl _IdlePTD,_KPTphys 124_IdlePTD: .long 0 /* phys addr of kernel PTD */ 125_KPTphys: .long 0 /* phys addr of kernel page tables */ 126 127 .globl _proc0paddr 128_proc0paddr: .long 0 /* address of proc 0 address space */ 129 130#ifdef BDE_DEBUGGER 131 .globl _bdb_exists /* flag to indicate BDE debugger is available */ 132_bdb_exists: .long 0 133#endif 134#if NAPM > 0 135 .globl _apm_current_gdt_pdesc /* current GDT pseudo desc. */ 136_apm_current_gdt_pdesc: 137 .word 0, 0, 0 138 139 .globl _bootstrap_gdt 140_bootstrap_gdt: 141 .space SIZEOF_GDT * BOOTSTRAP_GDT_NUM 142#endif /* NAPM */ 143 .globl tmpstk 144 .space 0x1000 145tmpstk: 146 147 148/* 149 * System Initialization 150 */ 151 .text 152 153/* 154 * btext: beginning of text section. 155 * Also the entry point (jumped to directly from the boot blocks). 156 */ 157NON_GPROF_ENTRY(btext) 158 movw $0x1234,0x472 /* warm boot */ 159 jmp 1f 160 /* 161 * XXX now that we load at 1MB is this still really used? 162 */ 163 .org 0x500 /* space for BIOS variables */ 164 1651: 166 /* Set up a real frame, some day we will be doing returns */ 167 pushl %ebp 168 movl %esp, %ebp 169 170 /* Don't trust what the BIOS gives for eflags. */ 171 pushl $PSL_MBO 172 popfl 173 174 /* 175 * This code is called in different ways depending on what loaded 176 * and started the kernel. This is used to detect how we get the 177 * arguments from the other code and what we do with them. 178 * 179 * Old disk boot blocks: 180 * (*btext)(howto, bootdev, cyloffset, esym); 181 * [return address == 0, and can NOT be returned to] 182 * [cyloffset was not supported by the FreeBSD boot code 183 * and always passed in as 0] 184 * [esym is also known as total in the boot code, and 185 * was never properly supported by the FreeBSD boot code] 186 * 187 * Old diskless netboot code: 188 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 189 * [return address != 0, and can NOT be returned to] 190 * If we are being booted by this code it will NOT work, 191 * so we are just going to halt if we find this case. 192 * 193 * New uniform boot code: 194 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 195 * [return address != 0, and can be returned to] 196 * 197 * There may seem to be a lot of wasted arguments in here, but 198 * that is so the newer boot code can still load very old kernels 199 * and old boot code can load new kernels. 200 */ 201 202 /* 203 * The old style disk boot blocks fake a frame on the stack and 204 * did an lret to get here. The frame on the stack has a return 205 * address of 0. 206 */ 207 cmpl $0,4(%ebp) 208 je 2f /* olddiskboot: */ 209 210 /* 211 * We have some form of return address, so this is either the 212 * old diskless netboot code, or the new uniform code. That can 213 * be detected by looking at the 5th argument, it if is 0 we 214 * we are being booted by the new unifrom boot code. 215 */ 216 cmpl $0,24(%ebp) 217 je 1f /* newboot: */ 218 219 /* 220 * Seems we have been loaded by the old diskless boot code, we 221 * don't stand a chance of running as the diskless structure 222 * changed considerably between the two, so just halt. 223 */ 224 hlt 225 226 /* 227 * We have been loaded by the new uniform boot code. 228 * Lets check the bootinfo version, and if we do not understand 229 * it we return to the loader with a status of 1 to indicate this error 230 */ 2311: /* newboot: */ 232 movl 28(%ebp),%ebx /* &bootinfo.version */ 233 movl BOOTINFO_VERSION(%ebx),%eax 234 cmpl $1,%eax /* We only understand version 1 */ 235 je 1f 236 movl $1,%eax /* Return status */ 237 leave 238 ret 239 2401: 241 /* 242 * If we have a kernelname copy it in 243 */ 244 movl BOOTINFO_KERNELNAME(%ebx),%esi 245 cmpl $0,%esi 246 je 1f /* No kernelname */ 247 lea _kernelname-KERNBASE,%edi 248 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 249 cld 250 rep 251 movsb 252 2531: 254#ifdef NFS 255 /* 256 * If we have a nfs_diskless structure copy it in 257 */ 258 movl BOOTINFO_NFS_DISKLESS(%ebx),%esi 259 cmpl $0,%esi 260 je 2f 261 lea _nfs_diskless-KERNBASE,%edi 262 movl $NFSDISKLESS_SIZE,%ecx 263 cld 264 rep 265 movsb 266 lea _nfs_diskless_valid-KERNBASE,%edi 267 movl $1,(%edi) 268#endif 269 270 /* 271 * The old style disk boot. 272 * (*btext)(howto, bootdev, cyloffset, esym); 273 * Note that the newer boot code just falls into here to pick 274 * up howto and bootdev, cyloffset and esym are no longer used 275 */ 2762: /* olddiskboot: */ 277 movl 8(%ebp),%eax 278 movl %eax,_boothowto-KERNBASE 279 movl 12(%ebp),%eax 280 movl %eax,_bootdev-KERNBASE 281 282 /* get the BIOS video mode pointer */ 283 movl $0x4a8, %ecx 284 movl (%ecx), %eax 285 movl %eax, %ecx 286 shrl $12, %ecx 287 andl $0xffff0000, %ecx 288 andl $0x0000ffff, %eax 289 orl %ecx, %eax 290 movl (%eax), %eax 291 movl %eax, %ecx 292 shrl $12, %ecx 293 andl $0xffff0000, %ecx 294 andl $0x0000ffff, %eax 295 orl %ecx, %eax 296 addl $KERNBASE, %eax 297 movl %eax, _video_mode_ptr-KERNBASE 298 299#if NAPM > 0 300 /* 301 * Setup APM BIOS: 302 * 303 * APM BIOS initialization should be done from real mode or V86 mode. 304 * 305 * (by HOSOKAWA, Tatsumi <hosokawa@mt.cs.keio.ac.jp>) 306 */ 307 308 /* 309 * Copy APM initializer under 1MB boundary: 310 * 311 * APM initializer program must switch the CPU to real mode. 312 * But FreeBSD kernel runs above 1MB boundary. So we must 313 * copy the initializer code to conventional memory. 314 */ 315 movl _apm_init_image_size-KERNBASE, %ecx /* size */ 316 lea _apm_init_image-KERNBASE, %esi /* source */ 317 movl $ APM_OURADDR, %edi /* destination */ 318 cld 319 rep 320 movsb 321 322 /* get GDT base */ 323 sgdt _apm_current_gdt_pdesc-KERNBASE 324 325 /* copy GDT to _bootstrap_gdt */ 326 xorl %ecx, %ecx 327 movw _apm_current_gdt_pdesc-KERNBASE, %cx 328 movl _apm_current_gdt_pdesc-KERNBASE+2, %esi 329 lea _bootstrap_gdt-KERNBASE, %edi 330 cld 331 rep 332 movsb 333 334 /* setup GDT pseudo descriptor */ 335 movw $(SIZEOF_GDT*BOOTSTRAP_GDT_NUM), %ax 336 movw %ax, _apm_current_gdt_pdesc-KERNBASE 337 leal _bootstrap_gdt-KERNBASE, %eax 338 movl %eax, _apm_current_gdt_pdesc-KERNBASE+2 339 340 /* load new GDTR */ 341 lgdt _apm_current_gdt_pdesc-KERNBASE 342 343 /* setup GDT for APM initializer */ 344 lea _bootstrap_gdt-KERNBASE, %ecx 345 movl $(APM_OURADDR), %eax /* use %ax for 15..0 */ 346 movl %eax, %ebx 347 shrl $16, %ebx /* use %bl for 23..16 */ 348 /* use %bh for 31..24 */ 349#define APM_SETUP_GDT(index, attrib) \ 350 movl $(index), %si ; \ 351 lea 0(%ecx,%esi,8), %edx ; \ 352 movw $0xffff, (%edx) ; \ 353 movw %ax, 2(%edx) ; \ 354 movb %bl, 4(%edx) ; \ 355 movw $(attrib), 5(%edx) ; \ 356 movb %bh, 7(%edx) 357 358 APM_SETUP_GDT(APM_INIT_CS_INDEX , CS32_ATTRIB) 359 APM_SETUP_GDT(APM_INIT_DS_INDEX , DS32_ATTRIB) 360 APM_SETUP_GDT(APM_INIT_CS16_INDEX, CS16_ATTRIB) 361 362 /* 363 * Call the initializer: 364 * 365 * direct intersegment call to conventional memory code 366 */ 367 .byte 0x9a /* actually, lcall $APM_INIT_CS_SEL, $0 */ 368 .long 0 369 .word APM_INIT_CS_SEL 370 371 movw %ax, _apm_version-KERNBASE 372 movl %ebx, _apm_cs_entry-KERNBASE 373 movw %cx, _apm_cs32_base-KERNBASE 374 shrl $16, %ecx 375 movw %cx, _apm_cs16_base-KERNBASE 376 movw %dx, _apm_ds_base-KERNBASE 377 movw %si, _apm_cs_limit-KERNBASE 378 shrl $16, %esi 379 movw %si, _apm_ds_limit-KERNBASE 380 movw %di, _apm_flags-KERNBASE 381#endif /* NAPM */ 382 383 /* Find out our CPU type. */ 384 385 /* Try to toggle alignment check flag; does not exist on 386. */ 386 pushfl 387 popl %eax 388 movl %eax,%ecx 389 orl $PSL_AC,%eax 390 pushl %eax 391 popfl 392 pushfl 393 popl %eax 394 xorl %ecx,%eax 395 andl $PSL_AC,%eax 396 pushl %ecx 397 popfl 398 399 testl %eax,%eax 400 jnz 1f 401 movl $CPU_386,_cpu-KERNBASE 402 jmp 2f 403 4041: /* Try to toggle identification flag; does not exist on early 486s. */ 405 pushfl 406 popl %eax 407 movl %eax,%ecx 408 xorl $PSL_ID,%eax 409 pushl %eax 410 popfl 411 pushfl 412 popl %eax 413 xorl %ecx,%eax 414 andl $PSL_ID,%eax 415 pushl %ecx 416 popfl 417 418 testl %eax,%eax 419 jnz 1f 420 movl $CPU_486,_cpu-KERNBASE 421 422 /* check for Cyrix 486DLC -- based on check routine */ 423 /* documented in "Cx486SLC/e SMM Programmer's Guide" */ 424 xorw %dx,%dx 425 cmpw %dx,%dx # set flags to known state 426 pushfw 427 popw %cx # store flags in ecx 428 movw $0xffff,%ax 429 movw $0x0004,%bx 430 divw %bx 431 pushfw 432 popw %ax 433 andw $0x08d5,%ax # mask off important bits 434 andw $0x08d5,%cx 435 cmpw %ax,%cx 436 437 jnz 2f # if flags changed, Intel chip 438 439 movl $CPU_486DLC,_cpu-KERNBASE # set CPU value for Cyrix 440 movl $0x69727943,_cpu_vendor-KERNBASE # store vendor string 441 movw $0x0078,_cpu_vendor-KERNBASE+4 442 443 invd # Start with guaranteed clean cache 444 /* Disable caching of the ISA hole only. */ 445 movb $CCR0,%al # Configuration Register index (CCR0) 446 outb %al,$0x22 447 inb $0x23,%al 448 orb $(CCR0_NC1|CCR0_BARB),%al 449 outb %al,$0x23 450 invd 451 jmp 2f 452 4531: /* Use the `cpuid' instruction. */ 454 xorl %eax,%eax 455 .byte 0x0f,0xa2 # cpuid 0 456 movl %ebx,_cpu_vendor-KERNBASE # store vendor string 457 movl %edx,_cpu_vendor+4-KERNBASE 458 movl %ecx,_cpu_vendor+8-KERNBASE 459 movb $0,_cpu_vendor+12-KERNBASE 460 461 movl $1,%eax 462 .byte 0x0f,0xa2 # cpuid 1 463 movl %eax,_cpu_id-KERNBASE # store cpu_id 464 rorl $8,%eax # extract family type 465 andl $15,%eax 466 cmpl $5,%eax 467 jae 1f 468 469 /* less than Pentium; must be 486 */ 470 movl $CPU_486,_cpu-KERNBASE 471 jmp 2f 472 4731: movl $CPU_586,_cpu-KERNBASE 4742: 475 476 /* 477 * Finished with old stack; load new %esp now instead of later so 478 * we can trace this code without having to worry about the trace 479 * trap clobbering the memory test or the zeroing of the bss+bootstrap 480 * page tables. 481 * 482 * XXX - wdboot clears the bss after testing that this is safe. 483 * This is too wasteful - memory below 640K is scarce. The boot 484 * program should check: 485 * text+data <= &stack_variable - more_space_for_stack 486 * text+data+bss+pad+space_for_page_tables <= end_of_memory 487 * Oops, the gdt is in the carcass of the boot program so clearing 488 * the rest of memory is still not possible. 489 */ 490 movl $tmpstk-KERNBASE,%esp /* bootstrap stack end location */ 491 492/* 493 * Virtual address space of kernel: 494 * 495 * text | data | bss | [syms] | page dir | proc0 kernel stack | usr stk map | Sysmap 496 * pages: 1 UPAGES (2) 1 NKPT (7) 497 */ 498 499/* find end of kernel image */ 500 movl $_end-KERNBASE,%ecx 501 addl $NBPG-1,%ecx /* page align up */ 502 andl $~(NBPG-1),%ecx 503 movl %ecx,%esi /* esi = start of free memory */ 504 movl %ecx,_KERNend-KERNBASE /* save end of kernel */ 505 506/* clear bss */ 507 movl $_edata-KERNBASE,%edi 508 subl %edi,%ecx /* get amount to clear */ 509 xorl %eax,%eax /* specify zero fill */ 510 cld 511 rep 512 stosb 513 514/* 515 * The value in esi is both the end of the kernel bss and a pointer to 516 * the kernel page directory, and is used by the rest of locore to build 517 * the tables. 518 * esi + 1(page dir) + 2(UPAGES) + 1(p0stack) + NKPT(number of kernel 519 * page table pages) is then passed on the stack to init386(first) as 520 * the value first. esi should ALWAYS be page aligned!! 521 */ 522 movl %esi,%ecx /* Get current first availiable address */ 523 524/* clear pagetables, page directory, stack, etc... */ 525 movl %esi,%edi /* base (page directory) */ 526 movl $((1+UPAGES+1+NKPT)*NBPG),%ecx /* amount to clear */ 527 xorl %eax,%eax /* specify zero fill */ 528 cld 529 rep 530 stosb 531 532/* physical address of Idle proc/kernel page directory */ 533 movl %esi,_IdlePTD-KERNBASE 534 535/* 536 * fillkpt 537 * eax = (page frame address | control | status) == pte 538 * ebx = address of page table 539 * ecx = how many pages to map 540 */ 541#define fillkpt \ 5421: movl %eax,(%ebx) ; \ 543 addl $NBPG,%eax ; /* increment physical address */ \ 544 addl $4,%ebx ; /* next pte */ \ 545 loop 1b ; 546 547/* 548 * Map Kernel 549 * 550 * First step - build page tables 551 */ 552#if defined (KGDB) || defined (BDE_DEBUGGER) 553 movl _KERNend-KERNBASE,%ecx /* this much memory, */ 554 shrl $PGSHIFT,%ecx /* for this many PTEs */ 555#ifdef BDE_DEBUGGER 556 cmpl $0xa0,%ecx /* XXX - cover debugger pages */ 557 jae 1f 558 movl $0xa0,%ecx 5591: 560#endif /* BDE_DEBUGGER */ 561 movl $PG_V|PG_KW,%eax /* kernel R/W, valid */ 562 lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 563 movl %ebx,_KPTphys-KERNBASE /* save in global */ 564 fillkpt 565 566#else /* !KGDB && !BDE_DEBUGGER */ 567 /* write protect kernel text (doesn't do a thing for 386's - only 486's) */ 568 movl $_etext-KERNBASE,%ecx /* get size of text */ 569 shrl $PGSHIFT,%ecx /* for this many PTEs */ 570 movl $PG_V|PG_KR,%eax /* specify read only */ 571 lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 572 movl %ebx,_KPTphys-KERNBASE /* save in global */ 573 fillkpt 574 575 /* data and bss are r/w */ 576 andl $PG_FRAME,%eax /* strip to just addr of bss */ 577 movl _KERNend-KERNBASE,%ecx /* calculate size */ 578 subl %eax,%ecx 579 shrl $PGSHIFT,%ecx 580 orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 581 fillkpt 582#endif /* KGDB || BDE_DEBUGGER */ 583 584/* now initialize the page dir, upages, p0stack PT, and page tables */ 585 586 movl $(1+UPAGES+1+NKPT),%ecx /* number of PTEs */ 587 movl %esi,%eax /* phys address of PTD */ 588 andl $PG_FRAME,%eax /* convert to PFN, should be a NOP */ 589 orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 590 movl %esi,%ebx /* calculate pte offset to ptd */ 591 shrl $PGSHIFT-2,%ebx 592 addl %esi,%ebx /* address of page directory */ 593 addl $((1+UPAGES+1)*NBPG),%ebx /* offset to kernel page tables */ 594 fillkpt 595 596/* map I/O memory map */ 597 598 movl _KPTphys-KERNBASE,%ebx /* base of kernel page tables */ 599 lea (0xa0 * PTESIZE)(%ebx),%ebx /* hardwire ISA hole at KERNBASE + 0xa0000 */ 600 movl $0x100-0xa0,%ecx /* for this many pte s, */ 601 movl $(0xa0000|PG_V|PG_KW|PG_N),%eax /* valid, kernel read/write, non-cacheable */ 602 movl %ebx,_atdevphys-KERNBASE /* save phys addr of ptes */ 603 fillkpt 604 605 /* map proc 0's kernel stack into user page table page */ 606 607 movl $UPAGES,%ecx /* for this many pte s, */ 608 lea (1*NBPG)(%esi),%eax /* physical address in proc 0 */ 609 lea (KERNBASE)(%eax),%edx /* change into virtual addr */ 610 movl %edx,_proc0paddr-KERNBASE /* save VA for proc 0 init */ 611 orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 612 lea ((1+UPAGES)*NBPG)(%esi),%ebx /* addr of stack page table in proc 0 */ 613 addl $(KSTKPTEOFF * PTESIZE),%ebx /* offset to kernel stack PTE */ 614 fillkpt 615 616/* 617 * Initialize kernel page table directory 618 */ 619 /* install a pde for temporary double map of bottom of VA */ 620 movl _KPTphys-KERNBASE,%eax 621 orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 622 movl %eax,(%esi) /* which is where temp maps! */ 623 624 /* initialize kernel pde's */ 625 movl $(NKPT),%ecx /* for this many PDEs */ 626 lea (KPTDI*PDESIZE)(%esi),%ebx /* offset of pde for kernel */ 627 fillkpt 628 629 /* install a pde recursively mapping page directory as a page table! */ 630 movl %esi,%eax /* phys address of ptd in proc 0 */ 631 orl $PG_V|PG_KW,%eax /* pde entry is valid */ 632 movl %eax,PTDPTDI*PDESIZE(%esi) /* which is where PTmap maps! */ 633 634 /* install a pde to map kernel stack for proc 0 */ 635 lea ((1+UPAGES)*NBPG)(%esi),%eax /* physical address of pt in proc 0 */ 636 orl $PG_V|PG_KW,%eax /* pde entry is valid */ 637 movl %eax,KSTKPTDI*PDESIZE(%esi) /* which is where kernel stack maps! */ 638 639#ifdef BDE_DEBUGGER 640 /* copy and convert stuff from old gdt and idt for debugger */ 641 642 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 643 jne 1f 644 movb $1,_bdb_exists-KERNBASE 6451: 646 pushal 647 subl $2*6,%esp 648 649 sgdt (%esp) 650 movl 2(%esp),%esi /* base address of current gdt */ 651 movl $_gdt-KERNBASE,%edi 652 movl %edi,2(%esp) 653 movl $8*18/4,%ecx 654 cld 655 rep /* copy gdt */ 656 movsl 657 movl $_gdt-KERNBASE,-8+2(%edi) /* adjust gdt self-ptr */ 658 movb $0x92,-8+5(%edi) 659 660 sidt 6(%esp) 661 movl 6+2(%esp),%esi /* base address of current idt */ 662 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 663 movw 8(%esi),%ax 664 movl %eax,bdb_dbg_ljmp+1-KERNBASE /* ... immediate offset ... */ 665 movl 8+2(%esi),%eax 666 movw %ax,bdb_dbg_ljmp+5-KERNBASE /* ... and selector for ljmp */ 667 movl 24+4(%esi),%eax /* same for bpt descriptor */ 668 movw 24(%esi),%ax 669 movl %eax,bdb_bpt_ljmp+1-KERNBASE 670 movl 24+2(%esi),%eax 671 movw %ax,bdb_bpt_ljmp+5-KERNBASE 672 673 movl $_idt-KERNBASE,%edi 674 movl %edi,6+2(%esp) 675 movl $8*4/4,%ecx 676 cld 677 rep /* copy idt */ 678 movsl 679 680 lgdt (%esp) 681 lidt 6(%esp) 682 683 addl $2*6,%esp 684 popal 685#endif /* BDE_DEBUGGER */ 686 687 /* load base of page directory and enable mapping */ 688 movl %esi,%eax /* phys address of ptd in proc 0 */ 689 movl %eax,%cr3 /* load ptd addr into mmu */ 690 movl %cr0,%eax /* get control word */ 691 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 692 movl %eax,%cr0 /* and let's page NOW! */ 693 694 pushl $begin /* jump to high mem */ 695 ret 696 697begin: /* now running relocated at KERNBASE where the system is linked to run */ 698 movl _atdevphys,%edx /* get pte PA */ 699 subl _KPTphys,%edx /* remove base of ptes, now have phys offset */ 700 shll $PGSHIFT-2,%edx /* corresponding to virt offset */ 701 addl $KERNBASE,%edx /* add virtual base */ 702 movl %edx,_atdevbase 703 704#if N_SC > 0 705 /* XXX: can't scinit relocate Crtat relative to atdevbase itself? */ 706 .globl _Crtat /* XXX - locore should not know about */ 707 movl _Crtat,%eax /* variables of device drivers (pccons)! */ 708 subl $(KERNBASE+0xA0000),%eax 709 addl %eax,%edx 710 movl %edx,_Crtat 711#endif 712 713 /* set up bootstrap stack - 48 bytes */ 714 movl $_kstack+UPAGES*NBPG-4*12,%esp /* bootstrap stack end location */ 715 xorl %eax,%eax /* mark end of frames */ 716 movl %eax,%ebp 717 movl _proc0paddr,%eax 718 movl %esi,PCB_CR3(%eax) 719 720#ifdef BDE_DEBUGGER 721 /* relocate debugger gdt entries */ 722 723 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 724 movl $9,%ecx 725reloc_gdt: 726 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 727 addl $8,%eax /* now KERNBASE>>24 */ 728 loop reloc_gdt 729 730 cmpl $0,_bdb_exists 731 je 1f 732 int $3 7331: 734#endif /* BDE_DEBUGGER */ 735 736 /* 737 * Skip over the page tables and the kernel stack 738 */ 739 lea ((1+UPAGES+1+NKPT)*NBPG)(%esi),%esi 740 741 pushl %esi /* value of first for init386(first) */ 742 call _init386 /* wire 386 chip for unix operation */ 743 popl %esi 744 745 .globl __ucodesel,__udatasel 746 747 pushl $0 /* unused */ 748 pushl __udatasel /* ss */ 749 pushl $0 /* esp - filled in by execve() */ 750 pushl $PSL_USERSET /* eflags (ring 0, int enab) */ 751 pushl __ucodesel /* cs */ 752 pushl $0 /* eip - filled in by execve() */ 753 subl $(12*4),%esp /* space for rest of registers */ 754 755 pushl %esp /* call main with frame pointer */ 756 call _main /* autoconfiguration, mountroot etc */ 757 758 addl $(13*4),%esp /* back to a frame we can return with */ 759 760 /* 761 * now we've run main() and determined what cpu-type we are, we can 762 * enable WP mode on i486 cpus and above. 763 */ 764#if defined(I486_CPU) || defined(I586_CPU) 765 cmpl $CPUCLASS_386,_cpu_class 766 je 1f 767 movl %cr0,%eax /* get control word */ 768 orl $CR0_WP,%eax /* enable write protect for all modes */ 769 movl %eax,%cr0 /* and do it */ 770#endif 771 /* 772 * on return from main(), we are process 1 773 * set up address space and stack so that we can 'return' to user mode 774 */ 7751: 776 movl __ucodesel,%eax 777 movl __udatasel,%ecx 778 779 movl %cx,%ds 780 movl %cx,%es 781 movl %ax,%fs /* double map cs to fs */ 782 movl %cx,%gs /* and ds to gs */ 783 iret /* goto user! */ 784 785#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 786 787NON_GPROF_ENTRY(sigcode) 788 call SIGF_HANDLER(%esp) 789 lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 790 /* copy at 8(%esp)) */ 791 pushl %eax 792 pushl %eax /* junk to fake return address */ 793 movl $103,%eax /* XXX sigreturn() */ 794 LCALL(0x7,0) /* enter kernel with args on stack */ 795 hlt /* never gets here */ 796 797 .globl _szsigcode 798_szsigcode: 799 .long _szsigcode-_sigcode 800