locore.s revision 3406
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 1.33 1994/10/06 09:22:47 rgrimes 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#ifdef APM 58#define ASM 59#include <machine/apm_bios.h> 60#include <machine/apm_segments.h> 61#endif 62 63/* 64 * XXX 65 * 66 * Note: This version greatly munged to avoid various assembler errors 67 * that may be fixed in newer versions of gas. Perhaps newer versions 68 * will have more pleasant appearance. 69 */ 70 71/* 72 * PTmap is recursive pagemap at top of virtual address space. 73 * Within PTmap, the page directory can be found (third indirection). 74 */ 75 .globl _PTmap,_PTD,_PTDpde,_Sysmap 76 .set _PTmap,PTDPTDI << PDRSHIFT 77 .set _PTD,_PTmap + (PTDPTDI * NBPG) 78 .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 79 80/* Sysmap is the base address of the kernel page tables */ 81 .set _Sysmap,_PTmap + (KPTDI * NBPG) 82 83/* 84 * APTmap, APTD is the alternate recursive pagemap. 85 * It's used when modifying another process's page tables. 86 */ 87 .globl _APTmap,_APTD,_APTDpde 88 .set _APTmap,APTDPTDI << PDRSHIFT 89 .set _APTD,_APTmap + (APTDPTDI * NBPG) 90 .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 91 92/* 93 * Access to each processes kernel stack is via a region of 94 * per-process address space (at the beginning), immediatly above 95 * the user process stack. 96 */ 97 .set _kstack,USRSTACK 98 .globl _kstack 99 100/* 101 * Globals 102 */ 103 .data 104 105 .globl _boothowto,_bootdev,_curpcb 106 107 .globl _cpu,_cold,_atdevbase,_cpu_vendor,_cpu_id 108 109 .globl _video_mode_ptr 110 111_cpu: .long 0 /* are we 386, 386sx, or 486 */ 112_cpu_id: .long 0 /* stepping ID */ 113_cpu_vendor: .space 20 /* CPU origin code */ 114_video_mode_ptr: .long 0 115_cold: .long 1 /* cold till we are not */ 116_atdevbase: .long 0 /* location of start of iomem in virtual */ 117_atdevphys: .long 0 /* location of device mapping ptes (phys) */ 118 119 .globl _KERNend 120_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 121 122 .globl _IdlePTD,_KPTphys 123_IdlePTD: .long 0 /* phys addr of kernel PTD */ 124_KPTphys: .long 0 /* phys addr of kernel page tables */ 125 126 .globl _proc0paddr 127_proc0paddr: .long 0 /* address of proc 0 address space */ 128 129#ifdef BDE_DEBUGGER 130 .globl _bdb_exists /* flag to indicate BDE debugger is available */ 131_bdb_exists: .long 0 132#endif 133#ifdef APM 134 .globl _apm_current_gdt_pdesc /* current GDT pseudo desc. */ 135_apm_current_gdt_pdesc: 136 .word 0, 0, 0 137 138 .globl _bootstrap_gdt 139_bootstrap_gdt: 140 .space SIZEOF_GDT * BOOTSTRAP_GDT_NUM 141#endif /* APM */ 142 .globl tmpstk 143 .space 0x1000 144tmpstk: 145 146 147/* 148 * System Initialization 149 */ 150 .text 151 152/* 153 * btext: beginning of text section. 154 * Also the entry point (jumped to directly from the boot blocks). 155 */ 156NON_GPROF_ENTRY(btext) 157 movw $0x1234,0x472 /* warm boot */ 158 jmp 1f 159 /* 160 * XXX now that we load at 1MB is this still really used? 161 */ 162 .org 0x500 /* space for BIOS variables */ 163 1641: 165 /* Set up a real frame, some day we will be doing returns */ 166 pushl %ebp 167 movl %esp, %ebp 168 169 /* Don't trust what the BIOS gives for eflags. */ 170 pushl $PSL_MBO 171 popfl 172 173 /* 174 * This code is called in different ways depending on what loaded 175 * and started the kernel. This is used to detect how we get the 176 * arguments from the other code and what we do with them. 177 * 178 * Old disk boot blocks: 179 * (*btext)(howto, bootdev, cyloffset, esym); 180 * [return address == 0, and can NOT be returned to] 181 * [cyloffset was not supported by the FreeBSD boot code 182 * and always passed in as 0] 183 * [esym is also known as total in the boot code, and 184 * was never properly supported by the FreeBSD boot code] 185 * 186 * Old diskless netboot code: 187 * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 188 * [return address != 0, and can NOT be returned to] 189 * If we are being booted by this code it will NOT work, 190 * so we are just going to halt if we find this case. 191 * 192 * New uniform boot code: 193 * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 194 * [return address != 0, and can be returned to] 195 * 196 * There may seem to be a lot of wasted arguments in here, but 197 * that is so the newer boot code can still load very old kernels 198 * and old boot code can load new kernels. 199 */ 200 201 /* 202 * The old style disk boot blocks fake a frame on the stack and 203 * did an lret to get here. The frame on the stack has a return 204 * address of 0. 205 */ 206 cmpl $0,4(%ebp) 207 je 2f /* olddiskboot: */ 208 209 /* 210 * We have some form of return address, so this is either the 211 * old diskless netboot code, or the new uniform code. That can 212 * be detected by looking at the 5th argument, it if is 0 we 213 * we are being booted by the new unifrom boot code. 214 */ 215 cmpl $0,24(%ebp) 216 je 1f /* newboot: */ 217 218 /* 219 * Seems we have been loaded by the old diskless boot code, we 220 * don't stand a chance of running as the diskless structure 221 * changed considerably between the two, so just halt. 222 */ 223 hlt 224 225 /* 226 * We have been loaded by the new uniform boot code. 227 * Lets check the bootinfo version, and if we do not understand 228 * it we return to the loader with a status of 1 to indicate this error 229 */ 2301: /* newboot: */ 231 movl 28(%ebp),%ebx /* &bootinfo.version */ 232 movl BOOTINFO_VERSION(%ebx),%eax 233 cmpl $1,%eax /* We only understand version 1 */ 234 je 1f 235 movl $1,%eax /* Return status */ 236 leave 237 ret 238 2391: 240 /* 241 * If we have a kernelname copy it in 242 */ 243 movl BOOTINFO_KERNELNAME(%ebx),%esi 244 cmpl $0,%esi 245 je 1f /* No kernelname */ 246 lea _kernelname-KERNBASE,%edi 247 movl $MAXPATHLEN,%ecx /* Brute force!!! */ 248 cld 249 rep 250 movsb 251 2521: 253#ifdef DISKLESS 254 /* 255 * If we have a nfs_diskless structure copy it in 256 */ 257 movl BOOTINFO_NFS_DISKLESS(%ebx),%esi 258 cmpl $0,%esi 259 je 2f 260 lea _nfs_diskless-KERNBASE,%edi 261 movl $NFSDISKLESS_SIZE,%ecx 262 cld 263 rep 264 movsb 265#endif 266 267 /* 268 * The old style disk boot. 269 * (*btext)(howto, bootdev, cyloffset, esym); 270 * Note that the newer boot code just falls into here to pick 271 * up howto and bootdev, cyloffset and esym are no longer used 272 */ 2732: /* olddiskboot: */ 274 movl 8(%ebp),%eax 275 movl %eax,_boothowto-KERNBASE 276 movl 12(%ebp),%eax 277 movl %eax,_bootdev-KERNBASE 278 279 /* get the BIOS video mode pointer */ 280 movl $0x4a8, %ecx 281 movl (%ecx), %eax 282 movl %eax, %ecx 283 shrl $12, %ecx 284 andl $0xffff0000, %ecx 285 andl $0x0000ffff, %eax 286 orl %ecx, %eax 287 movl (%eax), %eax 288 movl %eax, %ecx 289 shrl $12, %ecx 290 andl $0xffff0000, %ecx 291 andl $0x0000ffff, %eax 292 orl %ecx, %eax 293 addl $KERNBASE, %eax 294 movl %eax, _video_mode_ptr-KERNBASE 295 296#ifdef APM 297 /* 298 * Setup APM BIOS: 299 * 300 * APM BIOS initialization should be done from real mode or V86 mode. 301 * 302 * (by HOSOKAWA, Tatsumi <hosokawa@mt.cs.keio.ac.jp>) 303 */ 304 305 /* 306 * Copy APM initializer under 1MB boundary: 307 * 308 * APM initializer program must switch the CPU to real mode. 309 * But FreeBSD kernel runs above 1MB boundary. So we must 310 * copy the initializer code to conventional memory. 311 */ 312 movl _apm_init_image_size-KERNBASE, %ecx /* size */ 313 lea _apm_init_image-KERNBASE, %esi /* source */ 314 movl $ APM_OURADDR, %edi /* destination */ 315 cld 316 rep 317 movsb 318 319 /* get GDT base */ 320 sgdt _apm_current_gdt_pdesc-KERNBASE 321 322 /* copy GDT to _bootstrap_gdt */ 323 xorl %ecx, %ecx 324 movw _apm_current_gdt_pdesc-KERNBASE, %cx 325 movl _apm_current_gdt_pdesc-KERNBASE+2, %esi 326 lea _bootstrap_gdt-KERNBASE, %edi 327 cld 328 rep 329 movsb 330 331 /* setup GDT pseudo descriptor */ 332 movw $(SIZEOF_GDT*BOOTSTRAP_GDT_NUM), %ax 333 movw %ax, _apm_current_gdt_pdesc-KERNBASE 334 leal _bootstrap_gdt-KERNBASE, %eax 335 movl %eax, _apm_current_gdt_pdesc-KERNBASE+2 336 337 /* load new GDTR */ 338 lgdt _apm_current_gdt_pdesc-KERNBASE 339 340 /* setup GDT for APM initializer */ 341 lea _bootstrap_gdt-KERNBASE, %ecx 342 movl $(APM_OURADDR), %eax /* use %ax for 15..0 */ 343 movl %eax, %ebx 344 shrl $16, %ebx /* use %bl for 23..16 */ 345 /* use %bh for 31..24 */ 346#define APM_SETUP_GDT(index, attrib) \ 347 movl $(index), %si ; \ 348 lea 0(%ecx,%esi,8), %edx ; \ 349 movw $0xffff, (%edx) ; \ 350 movw %ax, 2(%edx) ; \ 351 movb %bl, 4(%edx) ; \ 352 movw $(attrib), 5(%edx) ; \ 353 movb %bh, 7(%edx) 354 355 APM_SETUP_GDT(APM_INIT_CS_INDEX , CS32_ATTRIB) 356 APM_SETUP_GDT(APM_INIT_DS_INDEX , DS32_ATTRIB) 357 APM_SETUP_GDT(APM_INIT_CS16_INDEX, CS16_ATTRIB) 358 359 /* 360 * Call the initializer: 361 * 362 * direct intersegment call to conventional memory code 363 */ 364 .byte 0x9a /* actually, lcall $APM_INIT_CS_SEL, $0 */ 365 .long 0 366 .word APM_INIT_CS_SEL 367 368 movw %ax, _apm_version-KERNBASE 369 movl %ebx, _apm_cs_entry-KERNBASE 370 movw %cx, _apm_cs32_base-KERNBASE 371 shrl $16, %ecx 372 movw %cx, _apm_cs16_base-KERNBASE 373 movw %dx, _apm_ds_base-KERNBASE 374 movw %si, _apm_cs_limit-KERNBASE 375 shrl $16, %esi 376 movw %si, _apm_ds_limit-KERNBASE 377 movw %di, _apm_flags-KERNBASE 378#endif /* APM */ 379 380 /* Find out our CPU type. */ 381 382 /* Try to toggle alignment check flag; does not exist on 386. */ 383 pushfl 384 popl %eax 385 movl %eax,%ecx 386 orl $PSL_AC,%eax 387 pushl %eax 388 popfl 389 pushfl 390 popl %eax 391 xorl %ecx,%eax 392 andl $PSL_AC,%eax 393 pushl %ecx 394 popfl 395 396 testl %eax,%eax 397 jnz 1f 398 movl $CPU_386,_cpu-KERNBASE 399 jmp 2f 400 4011: /* Try to toggle identification flag; does not exist on early 486s. */ 402 pushfl 403 popl %eax 404 movl %eax,%ecx 405 xorl $PSL_ID,%eax 406 pushl %eax 407 popfl 408 pushfl 409 popl %eax 410 xorl %ecx,%eax 411 andl $PSL_ID,%eax 412 pushl %ecx 413 popfl 414 415 testl %eax,%eax 416 jnz 1f 417 movl $CPU_486,_cpu-KERNBASE 418 419 /* check for Cyrix 486DLC -- based on check routine */ 420 /* documented in "Cx486SLC/e SMM Programmer's Guide" */ 421 xorw %dx,%dx 422 cmpw %dx,%dx # set flags to known state 423 pushfw 424 popw %cx # store flags in ecx 425 movw $0xffff,%ax 426 movw $0x0004,%bx 427 divw %bx 428 pushfw 429 popw %ax 430 andw $0x08d5,%ax # mask off important bits 431 andw $0x08d5,%cx 432 cmpw %ax,%cx 433 434 jnz 2f # if flags changed, Intel chip 435 436 movl $CPU_486DLC,_cpu-KERNBASE # set CPU value for Cyrix 437 movl $0x69727943,_cpu_vendor-KERNBASE # store vendor string 438 movw $0x0078,_cpu_vendor-KERNBASE+4 439 440 invd # Start with guaranteed clean cache 441 /* Disable caching of the ISA hole only. */ 442 movb $CCR0,%al # Configuration Register index (CCR0) 443 outb %al,$0x22 444 inb $0x23,%al 445 orb $(CCR0_NC1|CCR0_BARB),%al 446 outb %al,$0x23 447 invd 448 jmp 2f 449 4501: /* Use the `cpuid' instruction. */ 451 xorl %eax,%eax 452 .byte 0x0f,0xa2 # cpuid 0 453 movl %ebx,_cpu_vendor-KERNBASE # store vendor string 454 movl %edx,_cpu_vendor+4-KERNBASE 455 movl %ecx,_cpu_vendor+8-KERNBASE 456 movb $0,_cpu_vendor+12-KERNBASE 457 458 movl $1,%eax 459 .byte 0x0f,0xa2 # cpuid 1 460 movl %eax,_cpu_id-KERNBASE # store cpu_id 461 rorl $8,%eax # extract family type 462 andl $15,%eax 463 cmpl $5,%eax 464 jae 1f 465 466 /* less than Pentium; must be 486 */ 467 movl $CPU_486,_cpu-KERNBASE 468 jmp 2f 469 4701: movl $CPU_586,_cpu-KERNBASE 4712: 472 473 /* 474 * Finished with old stack; load new %esp now instead of later so 475 * we can trace this code without having to worry about the trace 476 * trap clobbering the memory test or the zeroing of the bss+bootstrap 477 * page tables. 478 * 479 * XXX - wdboot clears the bss after testing that this is safe. 480 * This is too wasteful - memory below 640K is scarce. The boot 481 * program should check: 482 * text+data <= &stack_variable - more_space_for_stack 483 * text+data+bss+pad+space_for_page_tables <= end_of_memory 484 * Oops, the gdt is in the carcass of the boot program so clearing 485 * the rest of memory is still not possible. 486 */ 487 movl $tmpstk-KERNBASE,%esp /* bootstrap stack end location */ 488 489/* 490 * Virtual address space of kernel: 491 * 492 * text | data | bss | [syms] | page dir | proc0 kernel stack | usr stk map | Sysmap 493 * pages: 1 UPAGES (2) 1 NKPT (7) 494 */ 495 496/* find end of kernel image */ 497 movl $_end-KERNBASE,%ecx 498 addl $NBPG-1,%ecx /* page align up */ 499 andl $~(NBPG-1),%ecx 500 movl %ecx,%esi /* esi = start of free memory */ 501 movl %ecx,_KERNend-KERNBASE /* save end of kernel */ 502 503/* clear bss */ 504 movl $_edata-KERNBASE,%edi 505 subl %edi,%ecx /* get amount to clear */ 506 xorl %eax,%eax /* specify zero fill */ 507 cld 508 rep 509 stosb 510 511/* 512 * The value in esi is both the end of the kernel bss and a pointer to 513 * the kernel page directory, and is used by the rest of locore to build 514 * the tables. 515 * esi + 1(page dir) + 2(UPAGES) + 1(p0stack) + NKPT(number of kernel 516 * page table pages) is then passed on the stack to init386(first) as 517 * the value first. esi should ALWAYS be page aligned!! 518 */ 519 movl %esi,%ecx /* Get current first availiable address */ 520 521/* clear pagetables, page directory, stack, etc... */ 522 movl %esi,%edi /* base (page directory) */ 523 movl $((1+UPAGES+1+NKPT)*NBPG),%ecx /* amount to clear */ 524 xorl %eax,%eax /* specify zero fill */ 525 cld 526 rep 527 stosb 528 529/* physical address of Idle proc/kernel page directory */ 530 movl %esi,_IdlePTD-KERNBASE 531 532/* 533 * fillkpt 534 * eax = (page frame address | control | status) == pte 535 * ebx = address of page table 536 * ecx = how many pages to map 537 */ 538#define fillkpt \ 5391: movl %eax,(%ebx) ; \ 540 addl $NBPG,%eax ; /* increment physical address */ \ 541 addl $4,%ebx ; /* next pte */ \ 542 loop 1b ; 543 544/* 545 * Map Kernel 546 * 547 * First step - build page tables 548 */ 549#if defined (KGDB) || defined (BDE_DEBUGGER) 550 movl _KERNend-KERNBASE,%ecx /* this much memory, */ 551 shrl $PGSHIFT,%ecx /* for this many PTEs */ 552#ifdef BDE_DEBUGGER 553 cmpl $0xa0,%ecx /* XXX - cover debugger pages */ 554 jae 1f 555 movl $0xa0,%ecx 5561: 557#endif /* BDE_DEBUGGER */ 558 movl $PG_V|PG_KW,%eax /* kernel R/W, valid */ 559 lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 560 movl %ebx,_KPTphys-KERNBASE /* save in global */ 561 fillkpt 562 563#else /* !KGDB && !BDE_DEBUGGER */ 564 /* write protect kernel text (doesn't do a thing for 386's - only 486's) */ 565 movl $_etext-KERNBASE,%ecx /* get size of text */ 566 shrl $PGSHIFT,%ecx /* for this many PTEs */ 567 movl $PG_V|PG_KR,%eax /* specify read only */ 568 lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 569 movl %ebx,_KPTphys-KERNBASE /* save in global */ 570 fillkpt 571 572 /* data and bss are r/w */ 573 andl $PG_FRAME,%eax /* strip to just addr of bss */ 574 movl _KERNend-KERNBASE,%ecx /* calculate size */ 575 subl %eax,%ecx 576 shrl $PGSHIFT,%ecx 577 orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 578 fillkpt 579#endif /* KGDB || BDE_DEBUGGER */ 580 581/* now initialize the page dir, upages, p0stack PT, and page tables */ 582 583 movl $(1+UPAGES+1+NKPT),%ecx /* number of PTEs */ 584 movl %esi,%eax /* phys address of PTD */ 585 andl $PG_FRAME,%eax /* convert to PFN, should be a NOP */ 586 orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 587 movl %esi,%ebx /* calculate pte offset to ptd */ 588 shrl $PGSHIFT-2,%ebx 589 addl %esi,%ebx /* address of page directory */ 590 addl $((1+UPAGES+1)*NBPG),%ebx /* offset to kernel page tables */ 591 fillkpt 592 593/* map I/O memory map */ 594 595 movl _KPTphys-KERNBASE,%ebx /* base of kernel page tables */ 596 lea (0xa0 * PTESIZE)(%ebx),%ebx /* hardwire ISA hole at KERNBASE + 0xa0000 */ 597 movl $0x100-0xa0,%ecx /* for this many pte s, */ 598 movl $(0xa0000|PG_V|PG_KW|PG_N),%eax /* valid, kernel read/write, non-cacheable */ 599 movl %ebx,_atdevphys-KERNBASE /* save phys addr of ptes */ 600 fillkpt 601 602 /* map proc 0's kernel stack into user page table page */ 603 604 movl $UPAGES,%ecx /* for this many pte s, */ 605 lea (1*NBPG)(%esi),%eax /* physical address in proc 0 */ 606 lea (KERNBASE)(%eax),%edx /* change into virtual addr */ 607 movl %edx,_proc0paddr-KERNBASE /* save VA for proc 0 init */ 608 orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 609 lea ((1+UPAGES)*NBPG)(%esi),%ebx /* addr of stack page table in proc 0 */ 610 addl $(KSTKPTEOFF * PTESIZE),%ebx /* offset to kernel stack PTE */ 611 fillkpt 612 613/* 614 * Initialize kernel page table directory 615 */ 616 /* install a pde for temporary double map of bottom of VA */ 617 movl _KPTphys-KERNBASE,%eax 618 orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 619 movl %eax,(%esi) /* which is where temp maps! */ 620 621 /* initialize kernel pde's */ 622 movl $(NKPT),%ecx /* for this many PDEs */ 623 lea (KPTDI*PDESIZE)(%esi),%ebx /* offset of pde for kernel */ 624 fillkpt 625 626 /* install a pde recursively mapping page directory as a page table! */ 627 movl %esi,%eax /* phys address of ptd in proc 0 */ 628 orl $PG_V|PG_KW,%eax /* pde entry is valid */ 629 movl %eax,PTDPTDI*PDESIZE(%esi) /* which is where PTmap maps! */ 630 631 /* install a pde to map kernel stack for proc 0 */ 632 lea ((1+UPAGES)*NBPG)(%esi),%eax /* physical address of pt in proc 0 */ 633 orl $PG_V|PG_KW,%eax /* pde entry is valid */ 634 movl %eax,KSTKPTDI*PDESIZE(%esi) /* which is where kernel stack maps! */ 635 636#ifdef BDE_DEBUGGER 637 /* copy and convert stuff from old gdt and idt for debugger */ 638 639 cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 640 jne 1f 641 movb $1,_bdb_exists-KERNBASE 6421: 643 pushal 644 subl $2*6,%esp 645 646 sgdt (%esp) 647 movl 2(%esp),%esi /* base address of current gdt */ 648 movl $_gdt-KERNBASE,%edi 649 movl %edi,2(%esp) 650 movl $8*18/4,%ecx 651 cld 652 rep /* copy gdt */ 653 movsl 654 movl $_gdt-KERNBASE,-8+2(%edi) /* adjust gdt self-ptr */ 655 movb $0x92,-8+5(%edi) 656 657 sidt 6(%esp) 658 movl 6+2(%esp),%esi /* base address of current idt */ 659 movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 660 movw 8(%esi),%ax 661 movl %eax,bdb_dbg_ljmp+1-KERNBASE /* ... immediate offset ... */ 662 movl 8+2(%esi),%eax 663 movw %ax,bdb_dbg_ljmp+5-KERNBASE /* ... and selector for ljmp */ 664 movl 24+4(%esi),%eax /* same for bpt descriptor */ 665 movw 24(%esi),%ax 666 movl %eax,bdb_bpt_ljmp+1-KERNBASE 667 movl 24+2(%esi),%eax 668 movw %ax,bdb_bpt_ljmp+5-KERNBASE 669 670 movl $_idt-KERNBASE,%edi 671 movl %edi,6+2(%esp) 672 movl $8*4/4,%ecx 673 cld 674 rep /* copy idt */ 675 movsl 676 677 lgdt (%esp) 678 lidt 6(%esp) 679 680 addl $2*6,%esp 681 popal 682#endif /* BDE_DEBUGGER */ 683 684 /* load base of page directory and enable mapping */ 685 movl %esi,%eax /* phys address of ptd in proc 0 */ 686 movl %eax,%cr3 /* load ptd addr into mmu */ 687 movl %cr0,%eax /* get control word */ 688 orl $CR0_PE|CR0_PG,%eax /* enable paging */ 689 movl %eax,%cr0 /* and let's page NOW! */ 690 691 pushl $begin /* jump to high mem */ 692 ret 693 694begin: /* now running relocated at KERNBASE where the system is linked to run */ 695 696 .globl _Crtat /* XXX - locore should not know about */ 697 movl _Crtat,%eax /* variables of device drivers (pccons)! */ 698 subl $(KERNBASE+0xA0000),%eax 699 movl _atdevphys,%edx /* get pte PA */ 700 subl _KPTphys,%edx /* remove base of ptes, now have phys offset */ 701 shll $PGSHIFT-2,%edx /* corresponding to virt offset */ 702 addl $KERNBASE,%edx /* add virtual base */ 703 movl %edx,_atdevbase 704 addl %eax,%edx 705 movl %edx,_Crtat 706 707 /* set up bootstrap stack - 48 bytes */ 708 movl $_kstack+UPAGES*NBPG-4*12,%esp /* bootstrap stack end location */ 709 xorl %eax,%eax /* mark end of frames */ 710 movl %eax,%ebp 711 movl _proc0paddr,%eax 712 movl %esi,PCB_CR3(%eax) 713 714#ifdef BDE_DEBUGGER 715 /* relocate debugger gdt entries */ 716 717 movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 718 movl $9,%ecx 719reloc_gdt: 720 movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 721 addl $8,%eax /* now KERNBASE>>24 */ 722 loop reloc_gdt 723 724 cmpl $0,_bdb_exists 725 je 1f 726 int $3 7271: 728#endif /* BDE_DEBUGGER */ 729 730 /* 731 * Skip over the page tables and the kernel stack 732 */ 733 lea ((1+UPAGES+1+NKPT)*NBPG)(%esi),%esi 734 735 pushl %esi /* value of first for init386(first) */ 736 call _init386 /* wire 386 chip for unix operation */ 737 popl %esi 738 739 .globl __ucodesel,__udatasel 740 741 pushl $0 /* unused */ 742 pushl __udatasel /* ss */ 743 pushl $0 /* esp - filled in by execve() */ 744 pushl $PSL_USERSET /* eflags (ring 0, int enab) */ 745 pushl __ucodesel /* cs */ 746 pushl $0 /* eip - filled in by execve() */ 747 subl $(12*4),%esp /* space for rest of registers */ 748 749 pushl %esp /* call main with frame pointer */ 750 call _main /* autoconfiguration, mountroot etc */ 751 752 addl $(13*4),%esp /* back to a frame we can return with */ 753 754 /* 755 * now we've run main() and determined what cpu-type we are, we can 756 * enable WP mode on i486 cpus and above. 757 */ 758#if defined(I486_CPU) || defined(I586_CPU) 759 cmpl $CPUCLASS_386,_cpu_class 760 je 1f 761 movl %cr0,%eax /* get control word */ 762 orl $CR0_WP,%eax /* enable write protect for all modes */ 763 movl %eax,%cr0 /* and do it */ 764#endif 765 /* 766 * on return from main(), we are process 1 767 * set up address space and stack so that we can 'return' to user mode 768 */ 7691: 770 movl __ucodesel,%eax 771 movl __udatasel,%ecx 772 773 movl %cx,%ds 774 movl %cx,%es 775 movl %ax,%fs /* double map cs to fs */ 776 movl %cx,%gs /* and ds to gs */ 777 iret /* goto user! */ 778 779#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 780 781NON_GPROF_ENTRY(sigcode) 782 call SIGF_HANDLER(%esp) 783 lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 784 /* copy at 8(%esp)) */ 785 pushl %eax 786 pushl %eax /* junk to fake return address */ 787 movl $103,%eax /* XXX sigreturn() */ 788 LCALL(0x7,0) /* enter kernel with args on stack */ 789 hlt /* never gets here */ 790 791 .globl _szsigcode 792_szsigcode: 793 .long _szsigcode-_sigcode 794