locore.s revision 3284
14Srgrimes/*- 24Srgrimes * Copyright (c) 1990 The Regents of the University of California. 34Srgrimes * All rights reserved. 44Srgrimes * 54Srgrimes * This code is derived from software contributed to Berkeley by 64Srgrimes * William Jolitz. 74Srgrimes * 84Srgrimes * Redistribution and use in source and binary forms, with or without 94Srgrimes * modification, are permitted provided that the following conditions 104Srgrimes * are met: 114Srgrimes * 1. Redistributions of source code must retain the above copyright 124Srgrimes * notice, this list of conditions and the following disclaimer. 134Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 144Srgrimes * notice, this list of conditions and the following disclaimer in the 154Srgrimes * documentation and/or other materials provided with the distribution. 164Srgrimes * 3. All advertising materials mentioning features or use of this software 174Srgrimes * must display the following acknowledgement: 184Srgrimes * This product includes software developed by the University of 194Srgrimes * California, Berkeley and its contributors. 204Srgrimes * 4. Neither the name of the University nor the names of its contributors 214Srgrimes * may be used to endorse or promote products derived from this software 224Srgrimes * without specific prior written permission. 234Srgrimes * 244Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 254Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 264Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 274Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 284Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 294Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 304Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 314Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 324Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 334Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 344Srgrimes * SUCH DAMAGE. 354Srgrimes * 36556Srgrimes * from: @(#)locore.s 7.3 (Berkeley) 5/13/91 373284Srgrimes * $Id: locore.s,v 1.30 1994/10/01 02:56:01 davidg Exp $ 384Srgrimes */ 394Srgrimes 404Srgrimes/* 41757Sdg * locore.s: FreeBSD machine support for the Intel 386 42757Sdg * originally from: locore.s, by William F. Jolitz 43757Sdg * 44757Sdg * Substantially rewritten by David Greenman, Rod Grimes, 45757Sdg * Bruce Evans, Wolfgang Solfrank, and many others. 464Srgrimes */ 474Srgrimes 482056Swollman#include "npx.h" /* for NNPX */ 492056Swollman#include "assym.s" /* system definitions */ 502056Swollman#include <machine/psl.h> /* processor status longword defs */ 512056Swollman#include <machine/pte.h> /* page table entry definitions */ 522056Swollman#include <sys/errno.h> /* error return codes */ 532056Swollman#include <machine/specialreg.h> /* x86 special registers */ 542056Swollman#include <machine/cputypes.h> /* x86 cpu type definitions */ 552056Swollman#include <sys/syscall.h> /* system call numbers */ 562056Swollman#include <machine/asmacros.h> /* miscellaneous asm macros */ 573258Sdg#ifdef APM 583258Sdg#define ASM 593258Sdg#include <machine/apm_bios.h> 603258Sdg#include <machine/apm_segments.h> 613258Sdg#endif 624Srgrimes 634Srgrimes/* 64757Sdg * XXX 65757Sdg * 664Srgrimes * Note: This version greatly munged to avoid various assembler errors 674Srgrimes * that may be fixed in newer versions of gas. Perhaps newer versions 684Srgrimes * will have more pleasant appearance. 694Srgrimes */ 704Srgrimes 71200Sdg/* 724Srgrimes * PTmap is recursive pagemap at top of virtual address space. 734Srgrimes * Within PTmap, the page directory can be found (third indirection). 744Srgrimes */ 75592Srgrimes .globl _PTmap,_PTD,_PTDpde,_Sysmap 76592Srgrimes .set _PTmap,PTDPTDI << PDRSHIFT 77592Srgrimes .set _PTD,_PTmap + (PTDPTDI * NBPG) 78757Sdg .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 79592Srgrimes 80757Sdg/* Sysmap is the base address of the kernel page tables */ 81608Srgrimes .set _Sysmap,_PTmap + (KPTDI * NBPG) 824Srgrimes 834Srgrimes/* 844Srgrimes * APTmap, APTD is the alternate recursive pagemap. 854Srgrimes * It's used when modifying another process's page tables. 864Srgrimes */ 87592Srgrimes .globl _APTmap,_APTD,_APTDpde 88592Srgrimes .set _APTmap,APTDPTDI << PDRSHIFT 89592Srgrimes .set _APTD,_APTmap + (APTDPTDI * NBPG) 90757Sdg .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 914Srgrimes 924Srgrimes/* 934Srgrimes * Access to each processes kernel stack is via a region of 944Srgrimes * per-process address space (at the beginning), immediatly above 954Srgrimes * the user process stack. 964Srgrimes */ 97570Srgrimes .set _kstack,USRSTACK 98134Sdg .globl _kstack 994Srgrimes 100556Srgrimes/* 101556Srgrimes * Globals 102556Srgrimes */ 103556Srgrimes .data 104556Srgrimes .globl _esym 105757Sdg_esym: .long 0 /* ptr to end of syms */ 106134Sdg 107592Srgrimes .globl _boothowto,_bootdev,_curpcb 108134Sdg 1091998Swollman .globl _cpu,_cold,_atdevbase,_cpu_vendor,_cpu_id 1102783Ssos 1112783Ssos .globl _video_mode_ptr 1122783Ssos 113757Sdg_cpu: .long 0 /* are we 386, 386sx, or 486 */ 1142216Sbde_cpu_id: .long 0 /* stepping ID */ 1152216Sbde_cpu_vendor: .space 20 /* CPU origin code */ 1162783Ssos_video_mode_ptr: .long 0 117757Sdg_cold: .long 1 /* cold till we are not */ 118757Sdg_atdevbase: .long 0 /* location of start of iomem in virtual */ 119757Sdg_atdevphys: .long 0 /* location of device mapping ptes (phys) */ 1204Srgrimes 121757Sdg .globl _KERNend 122757Sdg_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 123757Sdg 124592Srgrimes .globl _IdlePTD,_KPTphys 125757Sdg_IdlePTD: .long 0 /* phys addr of kernel PTD */ 126757Sdg_KPTphys: .long 0 /* phys addr of kernel page tables */ 1274Srgrimes 128757Sdg .globl _proc0paddr 129757Sdg_proc0paddr: .long 0 /* address of proc 0 address space */ 130134Sdg 131757Sdg#ifdef BDE_DEBUGGER 132757Sdg .globl _bdb_exists /* flag to indicate BDE debugger is available */ 1331321Sdg_bdb_exists: .long 0 134757Sdg#endif 1353258Sdg#ifdef APM 1363258Sdg .globl _apm_current_gdt_pdesc /* current GDT pseudo desc. */ 1373258Sdg_apm_current_gdt_pdesc: 1383258Sdg .byte 0, 0, 0 139718Swollman 1403258Sdg .globl _bootstrap_gdt 1413258Sdg_bootstrap_gdt: 1423258Sdg .space SIZEOF_GDT * BOOTSTRAP_GDT_NUM 1433258Sdg#endif /* APM */ 144757Sdg .globl tmpstk 145974Sdg .space 0x1000 1464Srgrimestmpstk: 147134Sdg 148134Sdg 149556Srgrimes/* 150556Srgrimes * System Initialization 151556Srgrimes */ 1524Srgrimes .text 153134Sdg 154134Sdg/* 155200Sdg * btext: beginning of text section. 156200Sdg * Also the entry point (jumped to directly from the boot blocks). 157134Sdg */ 1581321SdgNON_GPROF_ENTRY(btext) 159757Sdg movw $0x1234,0x472 /* warm boot */ 1604Srgrimes jmp 1f 1613284Srgrimes /* 1623284Srgrimes * XXX now that we load at 1MB is this still really used? 1633284Srgrimes */ 1641321Sdg .org 0x500 /* space for BIOS variables */ 1654Srgrimes 1663284Srgrimes1: 1672512Sbde /* Don't trust what the BIOS gives for eflags. */ 1682512Sbde pushl $PSL_MBO 1692486Sdg popfl 1702486Sdg 1714Srgrimes /* 1723284Srgrimes * This code is called in different ways depending on what loaded 1733284Srgrimes * and started the kernel. This is used to detect how we get the 1743284Srgrimes * arguments from the other code and what we do with them. 1753284Srgrimes * 1763284Srgrimes * Old disk boot blocks: 1773284Srgrimes * (*btext)(howto, bootdev, cyloffset, esym); 1783284Srgrimes * [return address == 0, and can NOT be returned to] 1793284Srgrimes * [cyloffset was not supported by the FreeBSD boot code 1803284Srgrimes * and always passed in as 0] 1813284Srgrimes * [esym is also known as total in the boot code, and 1823284Srgrimes * was never properly supported by the FreeBSD boot code] 1833284Srgrimes * 1843284Srgrimes * Old diskless netboot code: 1853284Srgrimes * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 1863284Srgrimes * [return address != 0, and can NOT be returned to] 1873284Srgrimes * If we are being booted by this code it will NOT work, 1883284Srgrimes * so we are just going to halt if we find this case. 1893284Srgrimes * 1903284Srgrimes * New uniform boot code: 1913284Srgrimes * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 1923284Srgrimes * [return address != 0, and can be returned to] 1933284Srgrimes * 1943284Srgrimes * There may seem to be a lot of wasted arguments in here, but 1953284Srgrimes * that is so the newer boot code can still load very old kernels. 1964Srgrimes */ 1973284Srgrimes 1983284Srgrimes /* 1993284Srgrimes * The old style disk boot blocks fake a frame on the stack and 2003284Srgrimes * did an lret to get here. The frame on the stack has a return 2013284Srgrimes * address of 0. 2023284Srgrimes */ 2033284Srgrimes cmpl $0,0x00(%esp) 2043284Srgrimes je 2f /* olddiskboot: */ 2053284Srgrimes 2063284Srgrimes /* 2073284Srgrimes * We have some form of return address, so this is either the 2083284Srgrimes * old diskless netboot code, or the new uniform code. That can 2093284Srgrimes * be detected by looking at the 5th argument, it if is 0 we 2103284Srgrimes * we are being booted by the new unifrom boot code. 2113284Srgrimes */ 2123284Srgrimes cmpl $0,0x14(%esp) 2133284Srgrimes je 1f /* newboot: */ 2143284Srgrimes 2153284Srgrimes /* 2163284Srgrimes * Seems we have been loaded by the old diskless boot code, we 2173284Srgrimes * don't stand a chance of running as the diskless structure 2183284Srgrimes * changed considerably between the two, so just halt. 2193284Srgrimes */ 2203284Srgrimes hlt 2213284Srgrimes 2223284Srgrimes /* 2233284Srgrimes * We have been loaded by the new uniform boot code, this kernel 2243284Srgrimes * is not yet ready to handle that, so for now fix up the stack 2253284Srgrimes * like a real subroutine and then return to the boot loader with 2263284Srgrimes * a status of 1 to indicate this error. 2273284Srgrimes */ 2283284Srgrimes1: /* newboot: */ 2293284Srgrimes pushl %ebp 2303284Srgrimes movl %esp,%ebp 2313284Srgrimes movl $1,%eax 2323284Srgrimes leave 2333284Srgrimes ret 2343284Srgrimes 2353284Srgrimes /* 2363284Srgrimes * The old style disk boot. 2373284Srgrimes * (*btext)(howto, bootdev, cyloffset, esym); 2383284Srgrimes * cyloffset is no longer copied 2393284Srgrimes * XXX Is esym still used for the end of the kernel some place??? 2403284Srgrimes * for now make sure we keep a correct value in it until I 2413284Srgrimes * can deterimine that. 2423284Srgrimes */ 2433284Srgrimes2: /* olddiskboot: */ 2442486Sdg movl 4(%esp),%eax 245570Srgrimes movl %eax,_boothowto-KERNBASE 2464Srgrimes movl 8(%esp),%eax 247570Srgrimes movl %eax,_bootdev-KERNBASE 248556Srgrimes movl 16(%esp),%eax 249570Srgrimes addl $KERNBASE,%eax 250570Srgrimes movl %eax,_esym-KERNBASE 2512783Ssos 2522783Ssos /* get the BIOS video mode pointer */ 2532783Ssos movl $0x4a8, %ecx 2542783Ssos movl (%ecx), %eax 2552783Ssos movl %eax, %ecx 2562783Ssos shrl $12, %ecx 2572783Ssos andl $0xffff0000, %ecx 2582783Ssos andl $0x0000ffff, %eax 2592783Ssos orl %ecx, %eax 2602783Ssos movl (%eax), %eax 2612783Ssos movl %eax, %ecx 2622783Ssos shrl $12, %ecx 2632783Ssos andl $0xffff0000, %ecx 2642783Ssos andl $0x0000ffff, %eax 2652783Ssos orl %ecx, %eax 2662783Ssos addl $KERNBASE, %eax 2672783Ssos movl %eax, _video_mode_ptr-KERNBASE 2682783Ssos 2693258Sdg#ifdef APM 2703258Sdg /* 2713258Sdg * Setup APM BIOS: 2723258Sdg * 2733258Sdg * APM BIOS initialization should be done from real mode or V86 mode. 2743258Sdg * 2753258Sdg * (by HOSOKAWA, Tatsumi <hosokawa@mt.cs.keio.ac.jp>) 2763258Sdg */ 2774Srgrimes 2783258Sdg /* 2793258Sdg * Copy APM initializer under 1MB boundary: 2803258Sdg * 2813258Sdg * APM initializer program must switch the CPU to real mode. 2823258Sdg * But FreeBSD kernel runs above 1MB boundary. So we must 2833258Sdg * copy the initializer code to conventional memory. 2843258Sdg */ 2853258Sdg movl _apm_init_image_size-KERNBASE, %ecx /* size */ 2863258Sdg lea _apm_init_image-KERNBASE, %esi /* source */ 2873258Sdg movl $ APM_OURADDR, %edi /* destination */ 2883258Sdg cld 2893258Sdg rep 2903258Sdg movsb 2913258Sdg 2923258Sdg /* get GDT base */ 2933258Sdg sgdt _apm_current_gdt_pdesc-KERNBASE 2943258Sdg 2953258Sdg /* copy GDT to _bootstrap_gdt */ 2963258Sdg xorl %ecx, %ecx 2973258Sdg movw _apm_current_gdt_pdesc-KERNBASE, %cx 2983258Sdg movl _apm_current_gdt_pdesc-KERNBASE+2, %esi 2993258Sdg lea _bootstrap_gdt-KERNBASE, %edi 3003258Sdg cld 3013258Sdg rep 3023258Sdg movsb 3033258Sdg 3043258Sdg /* setup GDT pseudo descriptor */ 3053258Sdg movw $(SIZEOF_GDT*BOOTSTRAP_GDT_NUM), %ax 3063258Sdg movw %ax, _apm_current_gdt_pdesc-KERNBASE 3073258Sdg leal _bootstrap_gdt-KERNBASE, %eax 3083258Sdg movl %eax, _apm_current_gdt_pdesc-KERNBASE+2 3093258Sdg 3103258Sdg /* load new GDTR */ 3113258Sdg lgdt _apm_current_gdt_pdesc-KERNBASE 3123258Sdg 3133258Sdg /* setup GDT for APM initializer */ 3143258Sdg lea _bootstrap_gdt-KERNBASE, %ecx 3153258Sdg movl $(APM_OURADDR), %eax /* use %ax for 15..0 */ 3163258Sdg movl %eax, %ebx 3173258Sdg shrl $16, %ebx /* use %bl for 23..16 */ 3183258Sdg /* use %bh for 31..24 */ 3193258Sdg#define APM_SETUP_GDT(index, attrib) \ 3203258Sdg movl $(index), %si ; \ 3213258Sdg lea 0(%ecx,%esi,8), %edx ; \ 3223258Sdg movw $0xffff, (%edx) ; \ 3233258Sdg movw %ax, 2(%edx) ; \ 3243258Sdg movb %bl, 4(%edx) ; \ 3253258Sdg movw $(attrib), 5(%edx) ; \ 3263258Sdg movb %bh, 7(%edx) 3273258Sdg 3283258Sdg APM_SETUP_GDT(APM_INIT_CS_INDEX , CS32_ATTRIB) 3293258Sdg APM_SETUP_GDT(APM_INIT_DS_INDEX , DS32_ATTRIB) 3303258Sdg APM_SETUP_GDT(APM_INIT_CS16_INDEX, CS16_ATTRIB) 3313258Sdg 3323258Sdg /* 3333258Sdg * Call the initializer: 3343258Sdg * 3353258Sdg * direct intersegment call to conventional memory code 3363258Sdg */ 3373258Sdg .byte 0x9a /* actually, lcall $APM_INIT_CS_SEL, $0 */ 3383258Sdg .long 0 3393258Sdg .word APM_INIT_CS_SEL 3403258Sdg 3413258Sdg movw %ax, _apm_version-KERNBASE 3423258Sdg movl %ebx, _apm_cs_entry-KERNBASE 3433258Sdg movw %cx, _apm_cs32_base-KERNBASE 3443258Sdg shrl $16, %ecx 3453258Sdg movw %cx, _apm_cs16_base-KERNBASE 3463258Sdg movw %dx, _apm_ds_base-KERNBASE 3473258Sdg movw %si, _apm_cs_limit-KERNBASE 3483258Sdg shrl $16, %esi 3493258Sdg movw %si, _apm_ds_limit-KERNBASE 3503258Sdg movw %di, _apm_flags-KERNBASE 3513258Sdg#endif /* APM */ 3523258Sdg 3531998Swollman /* Find out our CPU type. */ 3541321Sdg 3551998Swollman /* Try to toggle alignment check flag; does not exist on 386. */ 3561998Swollman pushfl 3571998Swollman popl %eax 3581998Swollman movl %eax,%ecx 3591998Swollman orl $PSL_AC,%eax 3601998Swollman pushl %eax 3611998Swollman popfl 3621998Swollman pushfl 3631998Swollman popl %eax 3641998Swollman xorl %ecx,%eax 3651998Swollman andl $PSL_AC,%eax 3661998Swollman pushl %ecx 3671998Swollman popfl 3681998Swollman 3691998Swollman testl %eax,%eax 3701998Swollman jnz 1f 3711998Swollman movl $CPU_386,_cpu-KERNBASE 372556Srgrimes jmp 2f 3731998Swollman 3741998Swollman1: /* Try to toggle identification flag; does not exist on early 486s. */ 3751998Swollman pushfl 3761998Swollman popl %eax 3771998Swollman movl %eax,%ecx 3781998Swollman xorl $PSL_ID,%eax 3791998Swollman pushl %eax 3801998Swollman popfl 3811998Swollman pushfl 3821998Swollman popl %eax 3831998Swollman xorl %ecx,%eax 3841998Swollman andl $PSL_ID,%eax 3851998Swollman pushl %ecx 3861998Swollman popfl 3871998Swollman 3881998Swollman testl %eax,%eax 3891998Swollman jnz 1f 3901998Swollman movl $CPU_486,_cpu-KERNBASE 3912495Spst 3922495Spst /* check for Cyrix 486DLC -- based on check routine */ 3932495Spst /* documented in "Cx486SLC/e SMM Programmer's Guide" */ 3942495Spst xorw %dx,%dx 3952495Spst cmpw %dx,%dx # set flags to known state 3962495Spst pushfw 3972495Spst popw %cx # store flags in ecx 3982495Spst movw $0xffff,%ax 3992495Spst movw $0x0004,%bx 4002495Spst divw %bx 4012495Spst pushfw 4022495Spst popw %ax 4032495Spst andw $0x08d5,%ax # mask off important bits 4042495Spst andw $0x08d5,%cx 4052495Spst cmpw %ax,%cx 4062495Spst 4072495Spst jnz 2f # if flags changed, Intel chip 4082495Spst 4092495Spst movl $CPU_486DLC,_cpu-KERNBASE # set CPU value for Cyrix 4102495Spst movl $0x69727943,_cpu_vendor-KERNBASE # store vendor string 4112495Spst movw $0x0078,_cpu_vendor-KERNBASE+4 4122495Spst 4132495Spst invd # Start with guaranteed clean cache 4142495Spst /* Disable caching of the ISA hole only. */ 4152495Spst movb $CCR0,%al # Configuration Register index (CCR0) 4162495Spst outb %al,$0x22 4172495Spst inb $0x23,%al 4183117Spst orb $(CCR0_NC1|CCR0_BARB),%al 4192495Spst outb %al,$0x23 4202495Spst invd 4211998Swollman jmp 2f 4221998Swollman 4231998Swollman1: /* Use the `cpuid' instruction. */ 4241998Swollman xorl %eax,%eax 4251998Swollman .byte 0x0f,0xa2 # cpuid 0 4261998Swollman movl %ebx,_cpu_vendor-KERNBASE # store vendor string 4271998Swollman movl %edx,_cpu_vendor+4-KERNBASE 4281998Swollman movl %ecx,_cpu_vendor+8-KERNBASE 4291998Swollman movb $0,_cpu_vendor+12-KERNBASE 4301998Swollman 4311998Swollman movl $1,%eax 4321998Swollman .byte 0x0f,0xa2 # cpuid 1 4331998Swollman movl %eax,_cpu_id-KERNBASE # store cpu_id 4341998Swollman rorl $8,%eax # extract family type 4351998Swollman andl $15,%eax 4361998Swollman cmpl $5,%eax 4371998Swollman jae 1f 4381998Swollman 4391998Swollman /* less than Pentium; must be 486 */ 4401998Swollman movl $CPU_486,_cpu-KERNBASE 4411998Swollman jmp 2f 4421998Swollman 4431998Swollman1: movl $CPU_586,_cpu-KERNBASE 444556Srgrimes2: 445556Srgrimes 4464Srgrimes /* 4474Srgrimes * Finished with old stack; load new %esp now instead of later so 4484Srgrimes * we can trace this code without having to worry about the trace 4494Srgrimes * trap clobbering the memory test or the zeroing of the bss+bootstrap 4504Srgrimes * page tables. 4514Srgrimes * 4524Srgrimes * XXX - wdboot clears the bss after testing that this is safe. 4534Srgrimes * This is too wasteful - memory below 640K is scarce. The boot 4544Srgrimes * program should check: 4554Srgrimes * text+data <= &stack_variable - more_space_for_stack 4564Srgrimes * text+data+bss+pad+space_for_page_tables <= end_of_memory 4574Srgrimes * Oops, the gdt is in the carcass of the boot program so clearing 4584Srgrimes * the rest of memory is still not possible. 4594Srgrimes */ 460757Sdg movl $tmpstk-KERNBASE,%esp /* bootstrap stack end location */ 4614Srgrimes 462570Srgrimes/* 463570Srgrimes * Virtual address space of kernel: 464570Srgrimes * 465570Srgrimes * text | data | bss | [syms] | page dir | proc0 kernel stack | usr stk map | Sysmap 466974Sdg * pages: 1 UPAGES (2) 1 NKPT (7) 467570Srgrimes */ 468570Srgrimes 4694Srgrimes/* find end of kernel image */ 470570Srgrimes movl $_end-KERNBASE,%ecx 471757Sdg addl $NBPG-1,%ecx /* page align up */ 4724Srgrimes andl $~(NBPG-1),%ecx 4731321Sdg movl %ecx,%esi /* esi = start of free memory */ 474757Sdg movl %ecx,_KERNend-KERNBASE /* save end of kernel */ 4754Srgrimes 476757Sdg/* clear bss */ 477570Srgrimes movl $_edata-KERNBASE,%edi 478760Srgrimes subl %edi,%ecx /* get amount to clear */ 479757Sdg xorl %eax,%eax /* specify zero fill */ 4804Srgrimes cld 4814Srgrimes rep 4824Srgrimes stosb 4834Srgrimes 484608Srgrimes/* 485974Sdg * The value in esi is both the end of the kernel bss and a pointer to 486974Sdg * the kernel page directory, and is used by the rest of locore to build 487974Sdg * the tables. 488974Sdg * esi + 1(page dir) + 2(UPAGES) + 1(p0stack) + NKPT(number of kernel 489757Sdg * page table pages) is then passed on the stack to init386(first) as 490757Sdg * the value first. esi should ALWAYS be page aligned!! 491608Srgrimes */ 492757Sdg movl %esi,%ecx /* Get current first availiable address */ 493608Srgrimes 494757Sdg/* clear pagetables, page directory, stack, etc... */ 495757Sdg movl %esi,%edi /* base (page directory) */ 496974Sdg movl $((1+UPAGES+1+NKPT)*NBPG),%ecx /* amount to clear */ 497757Sdg xorl %eax,%eax /* specify zero fill */ 498757Sdg cld 499757Sdg rep 500757Sdg stosb 501757Sdg 502757Sdg/* physical address of Idle proc/kernel page directory */ 503570Srgrimes movl %esi,_IdlePTD-KERNBASE 5044Srgrimes 505592Srgrimes/* 506592Srgrimes * fillkpt 507592Srgrimes * eax = (page frame address | control | status) == pte 508592Srgrimes * ebx = address of page table 509592Srgrimes * ecx = how many pages to map 510592Srgrimes */ 5114Srgrimes#define fillkpt \ 5124Srgrimes1: movl %eax,(%ebx) ; \ 513570Srgrimes addl $NBPG,%eax ; /* increment physical address */ \ 5144Srgrimes addl $4,%ebx ; /* next pte */ \ 5154Srgrimes loop 1b ; 5164Srgrimes 5174Srgrimes/* 5184Srgrimes * Map Kernel 5194Srgrimes * 5204Srgrimes * First step - build page tables 5214Srgrimes */ 522757Sdg#if defined (KGDB) || defined (BDE_DEBUGGER) 523757Sdg movl _KERNend-KERNBASE,%ecx /* this much memory, */ 524757Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 525757Sdg#ifdef BDE_DEBUGGER 526757Sdg cmpl $0xa0,%ecx /* XXX - cover debugger pages */ 527200Sdg jae 1f 528200Sdg movl $0xa0,%ecx 529200Sdg1: 530757Sdg#endif /* BDE_DEBUGGER */ 5312512Sbde movl $PG_V|PG_KW,%eax /* kernel R/W, valid */ 532757Sdg lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 533757Sdg movl %ebx,_KPTphys-KERNBASE /* save in global */ 5344Srgrimes fillkpt 5354Srgrimes 536757Sdg#else /* !KGDB && !BDE_DEBUGGER */ 537757Sdg /* write protect kernel text (doesn't do a thing for 386's - only 486's) */ 538757Sdg movl $_etext-KERNBASE,%ecx /* get size of text */ 539757Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 540757Sdg movl $PG_V|PG_KR,%eax /* specify read only */ 541757Sdg lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 542757Sdg movl %ebx,_KPTphys-KERNBASE /* save in global */ 543757Sdg fillkpt 544757Sdg 545757Sdg /* data and bss are r/w */ 546757Sdg andl $PG_FRAME,%eax /* strip to just addr of bss */ 547757Sdg movl _KERNend-KERNBASE,%ecx /* calculate size */ 548757Sdg subl %eax,%ecx 549757Sdg shrl $PGSHIFT,%ecx 550757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 551757Sdg fillkpt 5521321Sdg#endif /* KGDB || BDE_DEBUGGER */ 553757Sdg 554757Sdg/* now initialize the page dir, upages, p0stack PT, and page tables */ 555757Sdg 556974Sdg movl $(1+UPAGES+1+NKPT),%ecx /* number of PTEs */ 557757Sdg movl %esi,%eax /* phys address of PTD */ 558757Sdg andl $PG_FRAME,%eax /* convert to PFN, should be a NOP */ 5592512Sbde orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 560757Sdg movl %esi,%ebx /* calculate pte offset to ptd */ 561757Sdg shrl $PGSHIFT-2,%ebx 562757Sdg addl %esi,%ebx /* address of page directory */ 563757Sdg addl $((1+UPAGES+1)*NBPG),%ebx /* offset to kernel page tables */ 564757Sdg fillkpt 5651321Sdg 5664Srgrimes/* map I/O memory map */ 5674Srgrimes 568757Sdg movl _KPTphys-KERNBASE,%ebx /* base of kernel page tables */ 569757Sdg lea (0xa0 * PTESIZE)(%ebx),%ebx /* hardwire ISA hole at KERNBASE + 0xa0000 */ 570757Sdg movl $0x100-0xa0,%ecx /* for this many pte s, */ 5711046Sdg movl $(0xa0000|PG_V|PG_KW|PG_N),%eax /* valid, kernel read/write, non-cacheable */ 572757Sdg movl %ebx,_atdevphys-KERNBASE /* save phys addr of ptes */ 5734Srgrimes fillkpt 5744Srgrimes 5754Srgrimes /* map proc 0's kernel stack into user page table page */ 5764Srgrimes 577757Sdg movl $UPAGES,%ecx /* for this many pte s, */ 578757Sdg lea (1*NBPG)(%esi),%eax /* physical address in proc 0 */ 579757Sdg lea (KERNBASE)(%eax),%edx /* change into virtual addr */ 580757Sdg movl %edx,_proc0paddr-KERNBASE /* save VA for proc 0 init */ 581757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 582757Sdg lea ((1+UPAGES)*NBPG)(%esi),%ebx /* addr of stack page table in proc 0 */ 583757Sdg addl $(KSTKPTEOFF * PTESIZE),%ebx /* offset to kernel stack PTE */ 5844Srgrimes fillkpt 5854Srgrimes 5864Srgrimes/* 587757Sdg * Initialize kernel page table directory 5884Srgrimes */ 5894Srgrimes /* install a pde for temporary double map of bottom of VA */ 590757Sdg movl _KPTphys-KERNBASE,%eax 591757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 592757Sdg movl %eax,(%esi) /* which is where temp maps! */ 5934Srgrimes 594757Sdg /* initialize kernel pde's */ 595974Sdg movl $(NKPT),%ecx /* for this many PDEs */ 596757Sdg lea (KPTDI*PDESIZE)(%esi),%ebx /* offset of pde for kernel */ 5974Srgrimes fillkpt 5984Srgrimes 5994Srgrimes /* install a pde recursively mapping page directory as a page table! */ 600757Sdg movl %esi,%eax /* phys address of ptd in proc 0 */ 601757Sdg orl $PG_V|PG_KW,%eax /* pde entry is valid */ 602757Sdg movl %eax,PTDPTDI*PDESIZE(%esi) /* which is where PTmap maps! */ 6034Srgrimes 6044Srgrimes /* install a pde to map kernel stack for proc 0 */ 605757Sdg lea ((1+UPAGES)*NBPG)(%esi),%eax /* physical address of pt in proc 0 */ 606757Sdg orl $PG_V|PG_KW,%eax /* pde entry is valid */ 607757Sdg movl %eax,KSTKPTDI*PDESIZE(%esi) /* which is where kernel stack maps! */ 6084Srgrimes 609757Sdg#ifdef BDE_DEBUGGER 6104Srgrimes /* copy and convert stuff from old gdt and idt for debugger */ 6114Srgrimes 612757Sdg cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 6134Srgrimes jne 1f 614570Srgrimes movb $1,_bdb_exists-KERNBASE 6154Srgrimes1: 6164Srgrimes pushal 6174Srgrimes subl $2*6,%esp 6184Srgrimes 6194Srgrimes sgdt (%esp) 620757Sdg movl 2(%esp),%esi /* base address of current gdt */ 621570Srgrimes movl $_gdt-KERNBASE,%edi 6224Srgrimes movl %edi,2(%esp) 6234Srgrimes movl $8*18/4,%ecx 6241688Sdg cld 625757Sdg rep /* copy gdt */ 6264Srgrimes movsl 627570Srgrimes movl $_gdt-KERNBASE,-8+2(%edi) /* adjust gdt self-ptr */ 6284Srgrimes movb $0x92,-8+5(%edi) 6294Srgrimes 6304Srgrimes sidt 6(%esp) 631757Sdg movl 6+2(%esp),%esi /* base address of current idt */ 632757Sdg movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 6334Srgrimes movw 8(%esi),%ax 634570Srgrimes movl %eax,bdb_dbg_ljmp+1-KERNBASE /* ... immediate offset ... */ 6354Srgrimes movl 8+2(%esi),%eax 636570Srgrimes movw %ax,bdb_dbg_ljmp+5-KERNBASE /* ... and selector for ljmp */ 637757Sdg movl 24+4(%esi),%eax /* same for bpt descriptor */ 6384Srgrimes movw 24(%esi),%ax 639570Srgrimes movl %eax,bdb_bpt_ljmp+1-KERNBASE 6404Srgrimes movl 24+2(%esi),%eax 641570Srgrimes movw %ax,bdb_bpt_ljmp+5-KERNBASE 6424Srgrimes 643570Srgrimes movl $_idt-KERNBASE,%edi 6444Srgrimes movl %edi,6+2(%esp) 6454Srgrimes movl $8*4/4,%ecx 6461688Sdg cld 647757Sdg rep /* copy idt */ 6484Srgrimes movsl 6494Srgrimes 6504Srgrimes lgdt (%esp) 6514Srgrimes lidt 6(%esp) 6524Srgrimes 6534Srgrimes addl $2*6,%esp 6544Srgrimes popal 6551321Sdg#endif /* BDE_DEBUGGER */ 6564Srgrimes 657592Srgrimes /* load base of page directory and enable mapping */ 658757Sdg movl %esi,%eax /* phys address of ptd in proc 0 */ 659757Sdg movl %eax,%cr3 /* load ptd addr into mmu */ 660757Sdg movl %cr0,%eax /* get control word */ 661757Sdg orl $CR0_PE|CR0_PG,%eax /* enable paging */ 662757Sdg movl %eax,%cr0 /* and let's page NOW! */ 6634Srgrimes 664757Sdg pushl $begin /* jump to high mem */ 6654Srgrimes ret 6664Srgrimes 667570Srgrimesbegin: /* now running relocated at KERNBASE where the system is linked to run */ 6684Srgrimes 669757Sdg .globl _Crtat /* XXX - locore should not know about */ 670757Sdg movl _Crtat,%eax /* variables of device drivers (pccons)! */ 671592Srgrimes subl $(KERNBASE+0xA0000),%eax 672757Sdg movl _atdevphys,%edx /* get pte PA */ 673757Sdg subl _KPTphys,%edx /* remove base of ptes, now have phys offset */ 674757Sdg shll $PGSHIFT-2,%edx /* corresponding to virt offset */ 675757Sdg addl $KERNBASE,%edx /* add virtual base */ 676570Srgrimes movl %edx,_atdevbase 6774Srgrimes addl %eax,%edx 6784Srgrimes movl %edx,_Crtat 6794Srgrimes 680757Sdg /* set up bootstrap stack - 48 bytes */ 681570Srgrimes movl $_kstack+UPAGES*NBPG-4*12,%esp /* bootstrap stack end location */ 682757Sdg xorl %eax,%eax /* mark end of frames */ 6834Srgrimes movl %eax,%ebp 684570Srgrimes movl _proc0paddr,%eax 685570Srgrimes movl %esi,PCB_CR3(%eax) 6864Srgrimes 687757Sdg#ifdef BDE_DEBUGGER 6884Srgrimes /* relocate debugger gdt entries */ 6894Srgrimes 690757Sdg movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 6914Srgrimes movl $9,%ecx 6924Srgrimesreloc_gdt: 6931321Sdg movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 694757Sdg addl $8,%eax /* now KERNBASE>>24 */ 6954Srgrimes loop reloc_gdt 6964Srgrimes 6974Srgrimes cmpl $0,_bdb_exists 6984Srgrimes je 1f 6994Srgrimes int $3 7004Srgrimes1: 7011321Sdg#endif /* BDE_DEBUGGER */ 7024Srgrimes 703608Srgrimes /* 704608Srgrimes * Skip over the page tables and the kernel stack 705608Srgrimes */ 706974Sdg lea ((1+UPAGES+1+NKPT)*NBPG)(%esi),%esi 707608Srgrimes 708757Sdg pushl %esi /* value of first for init386(first) */ 709757Sdg call _init386 /* wire 386 chip for unix operation */ 7101549Srgrimes popl %esi 711200Sdg 7121549Srgrimes .globl __ucodesel,__udatasel 7131549Srgrimes 7141549Srgrimes pushl $0 /* unused */ 7151549Srgrimes pushl __udatasel /* ss */ 7161549Srgrimes pushl $0 /* esp - filled in by execve() */ 7172500Sdg pushl $PSL_USERSET /* eflags (ring 0, int enab) */ 7181549Srgrimes pushl __ucodesel /* cs */ 7191549Srgrimes pushl $0 /* eip - filled in by execve() */ 7201549Srgrimes subl $(12*4),%esp /* space for rest of registers */ 7211549Srgrimes 7221549Srgrimes pushl %esp /* call main with frame pointer */ 723757Sdg call _main /* autoconfiguration, mountroot etc */ 7244Srgrimes 7251549Srgrimes addl $(13*4),%esp /* back to a frame we can return with */ 7261549Srgrimes 727134Sdg /* 728570Srgrimes * now we've run main() and determined what cpu-type we are, we can 729570Srgrimes * enable WP mode on i486 cpus and above. 7301058Sdg */ 7311058Sdg#if defined(I486_CPU) || defined(I586_CPU) 7321058Sdg cmpl $CPUCLASS_386,_cpu_class 7331058Sdg je 1f 7341058Sdg movl %cr0,%eax /* get control word */ 7351058Sdg orl $CR0_WP,%eax /* enable write protect for all modes */ 7361058Sdg movl %eax,%cr0 /* and do it */ 7371058Sdg#endif 7381058Sdg /* 739134Sdg * on return from main(), we are process 1 740134Sdg * set up address space and stack so that we can 'return' to user mode 741134Sdg */ 7421058Sdg1: 7434Srgrimes movl __ucodesel,%eax 7444Srgrimes movl __udatasel,%ecx 7451549Srgrimes 7464Srgrimes movl %cx,%ds 7474Srgrimes movl %cx,%es 748757Sdg movl %ax,%fs /* double map cs to fs */ 749757Sdg movl %cx,%gs /* and ds to gs */ 7501549Srgrimes iret /* goto user! */ 7514Srgrimes 7521549Srgrimes#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 7534Srgrimes 754200SdgNON_GPROF_ENTRY(sigcode) 755592Srgrimes call SIGF_HANDLER(%esp) 756757Sdg lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 757757Sdg /* copy at 8(%esp)) */ 7584Srgrimes pushl %eax 759757Sdg pushl %eax /* junk to fake return address */ 760757Sdg movl $103,%eax /* XXX sigreturn() */ 761757Sdg LCALL(0x7,0) /* enter kernel with args on stack */ 762757Sdg hlt /* never gets here */ 7634Srgrimes 7644Srgrimes .globl _szsigcode 7654Srgrimes_szsigcode: 7664Srgrimes .long _szsigcode-_sigcode 767