locore.s revision 4217
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 374217Sphk * $Id: locore.s,v 1.43 1994/10/31 17:20:15 joerg 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 "assym.s" /* system definitions */ 492056Swollman#include <machine/psl.h> /* processor status longword defs */ 502056Swollman#include <machine/pte.h> /* page table entry definitions */ 512056Swollman#include <sys/errno.h> /* error return codes */ 522056Swollman#include <machine/specialreg.h> /* x86 special registers */ 532056Swollman#include <machine/cputypes.h> /* x86 cpu type definitions */ 542056Swollman#include <sys/syscall.h> /* system call numbers */ 552056Swollman#include <machine/asmacros.h> /* miscellaneous asm macros */ 563489Sphk#include "apm.h" 573489Sphk#if NAPM > 0 583258Sdg#define ASM 593258Sdg#include <machine/apm_bios.h> 603258Sdg#include <machine/apm_segments.h> 613489Sphk#endif /* NAPM */ 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 */ 753861Sbde .globl _PTmap,_PTD,_PTDpde 76592Srgrimes .set _PTmap,PTDPTDI << PDRSHIFT 77592Srgrimes .set _PTD,_PTmap + (PTDPTDI * NBPG) 78757Sdg .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 79592Srgrimes 803861Sbde/* 813861Sbde * Sysmap is the base address of the kernel page tables. 823861Sbde * It is a bogus interface for kgdb and isn't used by the kernel itself. 833861Sbde */ 84608Srgrimes .set _Sysmap,_PTmap + (KPTDI * NBPG) 854Srgrimes 864Srgrimes/* 874Srgrimes * APTmap, APTD is the alternate recursive pagemap. 884Srgrimes * It's used when modifying another process's page tables. 894Srgrimes */ 90592Srgrimes .globl _APTmap,_APTD,_APTDpde 91592Srgrimes .set _APTmap,APTDPTDI << PDRSHIFT 92592Srgrimes .set _APTD,_APTmap + (APTDPTDI * NBPG) 93757Sdg .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 944Srgrimes 954Srgrimes/* 964Srgrimes * Access to each processes kernel stack is via a region of 974Srgrimes * per-process address space (at the beginning), immediatly above 984Srgrimes * the user process stack. 994Srgrimes */ 100570Srgrimes .set _kstack,USRSTACK 101134Sdg .globl _kstack 1024Srgrimes 103556Srgrimes/* 104556Srgrimes * Globals 105556Srgrimes */ 106556Srgrimes .data 107134Sdg 1083842Sdg .globl tmpstk 1093842Sdg .space 0x1000 /* space for tmpstk - temporary stack */ 1103842Sdgtmpstk: 1114012Sbde/* 1124012Sbde * Dummy frame at top of tmpstk to help debuggers print a nice stack trace. 1134012Sbde */ 1144012Sbde .long tmpstk+8 /* caller's %ebp */ 1154012Sbde .long _cpu_switch /* caller */ 1164012Sbde .long 0 /* %ebp == 0 should terminate trace */ 1174012Sbde .long _mvesp /* in case %ebp == 0 doesn't work ... */ 1184012Sbde .long 0x11111111, 0x22222222, 0x33333333, 0x44444444, 0x55555555 1193842Sdg 1203861Sbde .globl _boothowto,_bootdev 121134Sdg 1221998Swollman .globl _cpu,_cold,_atdevbase,_cpu_vendor,_cpu_id 1232783Ssos 124757Sdg_cpu: .long 0 /* are we 386, 386sx, or 486 */ 1252216Sbde_cpu_id: .long 0 /* stepping ID */ 1262216Sbde_cpu_vendor: .space 20 /* CPU origin code */ 127757Sdg_cold: .long 1 /* cold till we are not */ 128757Sdg_atdevbase: .long 0 /* location of start of iomem in virtual */ 129757Sdg_atdevphys: .long 0 /* location of device mapping ptes (phys) */ 1304Srgrimes 131757Sdg_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 132757Sdg 1333861Sbde .globl _IdlePTD 134757Sdg_IdlePTD: .long 0 /* phys addr of kernel PTD */ 1353861Sbde 136757Sdg_KPTphys: .long 0 /* phys addr of kernel page tables */ 1374Srgrimes 138757Sdg .globl _proc0paddr 139757Sdg_proc0paddr: .long 0 /* address of proc 0 address space */ 140134Sdg 141757Sdg#ifdef BDE_DEBUGGER 142757Sdg .globl _bdb_exists /* flag to indicate BDE debugger is available */ 1431321Sdg_bdb_exists: .long 0 144757Sdg#endif 1453489Sphk#if NAPM > 0 1463258Sdg .globl _apm_current_gdt_pdesc /* current GDT pseudo desc. */ 1473258Sdg_apm_current_gdt_pdesc: 1483314Sdg .word 0, 0, 0 149718Swollman 1503258Sdg .globl _bootstrap_gdt 1513258Sdg_bootstrap_gdt: 1523258Sdg .space SIZEOF_GDT * BOOTSTRAP_GDT_NUM 1533489Sphk#endif /* NAPM */ 154134Sdg 155556Srgrimes/* 156556Srgrimes * System Initialization 157556Srgrimes */ 1584Srgrimes .text 159134Sdg 160134Sdg/* 161200Sdg * btext: beginning of text section. 162200Sdg * Also the entry point (jumped to directly from the boot blocks). 163134Sdg */ 1641321SdgNON_GPROF_ENTRY(btext) 165757Sdg movw $0x1234,0x472 /* warm boot */ 1664Srgrimes jmp 1f 1673284Srgrimes /* 1683284Srgrimes * XXX now that we load at 1MB is this still really used? 1693284Srgrimes */ 1701321Sdg .org 0x500 /* space for BIOS variables */ 1714Srgrimes 1723284Srgrimes1: 1733384Srgrimes /* Set up a real frame, some day we will be doing returns */ 1743384Srgrimes pushl %ebp 1753384Srgrimes movl %esp, %ebp 1763384Srgrimes 1772512Sbde /* Don't trust what the BIOS gives for eflags. */ 1782512Sbde pushl $PSL_MBO 1792486Sdg popfl 1802486Sdg 1814217Sphk /* Don't trust what the BIOS gives for %fs and %gs. */ 1824217Sphk mov %ds, %ax 1834217Sphk mov %ax, %fs 1844217Sphk mov %ax, %gs 1854217Sphk 1864Srgrimes /* 1873284Srgrimes * This code is called in different ways depending on what loaded 1883284Srgrimes * and started the kernel. This is used to detect how we get the 1893284Srgrimes * arguments from the other code and what we do with them. 1903284Srgrimes * 1913284Srgrimes * Old disk boot blocks: 1923284Srgrimes * (*btext)(howto, bootdev, cyloffset, esym); 1933284Srgrimes * [return address == 0, and can NOT be returned to] 1943284Srgrimes * [cyloffset was not supported by the FreeBSD boot code 1953284Srgrimes * and always passed in as 0] 1963284Srgrimes * [esym is also known as total in the boot code, and 1973284Srgrimes * was never properly supported by the FreeBSD boot code] 1983284Srgrimes * 1993284Srgrimes * Old diskless netboot code: 2003284Srgrimes * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 2013284Srgrimes * [return address != 0, and can NOT be returned to] 2023284Srgrimes * If we are being booted by this code it will NOT work, 2033284Srgrimes * so we are just going to halt if we find this case. 2043284Srgrimes * 2053284Srgrimes * New uniform boot code: 2063284Srgrimes * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 2073284Srgrimes * [return address != 0, and can be returned to] 2083284Srgrimes * 2093284Srgrimes * There may seem to be a lot of wasted arguments in here, but 2103384Srgrimes * that is so the newer boot code can still load very old kernels 2113384Srgrimes * and old boot code can load new kernels. 2124Srgrimes */ 2133284Srgrimes 2143284Srgrimes /* 2153284Srgrimes * The old style disk boot blocks fake a frame on the stack and 2163284Srgrimes * did an lret to get here. The frame on the stack has a return 2173284Srgrimes * address of 0. 2183284Srgrimes */ 2193384Srgrimes cmpl $0,4(%ebp) 2203284Srgrimes je 2f /* olddiskboot: */ 2213284Srgrimes 2223284Srgrimes /* 2233284Srgrimes * We have some form of return address, so this is either the 2243284Srgrimes * old diskless netboot code, or the new uniform code. That can 2253284Srgrimes * be detected by looking at the 5th argument, it if is 0 we 2263284Srgrimes * we are being booted by the new unifrom boot code. 2273284Srgrimes */ 2283384Srgrimes cmpl $0,24(%ebp) 2293284Srgrimes je 1f /* newboot: */ 2303284Srgrimes 2313284Srgrimes /* 2323284Srgrimes * Seems we have been loaded by the old diskless boot code, we 2333284Srgrimes * don't stand a chance of running as the diskless structure 2343284Srgrimes * changed considerably between the two, so just halt. 2353284Srgrimes */ 2363284Srgrimes hlt 2373284Srgrimes 2383284Srgrimes /* 2393384Srgrimes * We have been loaded by the new uniform boot code. 2403384Srgrimes * Lets check the bootinfo version, and if we do not understand 2413384Srgrimes * it we return to the loader with a status of 1 to indicate this error 2423284Srgrimes */ 2433284Srgrimes1: /* newboot: */ 2443384Srgrimes movl 28(%ebp),%ebx /* &bootinfo.version */ 2453384Srgrimes movl BOOTINFO_VERSION(%ebx),%eax 2463384Srgrimes cmpl $1,%eax /* We only understand version 1 */ 2473384Srgrimes je 1f 2483384Srgrimes movl $1,%eax /* Return status */ 2493384Srgrimes leave 2503384Srgrimes ret 2513284Srgrimes 2523384Srgrimes1: 2533284Srgrimes /* 2543384Srgrimes * If we have a kernelname copy it in 2553384Srgrimes */ 2563384Srgrimes movl BOOTINFO_KERNELNAME(%ebx),%esi 2573384Srgrimes cmpl $0,%esi 2583384Srgrimes je 1f /* No kernelname */ 2593384Srgrimes lea _kernelname-KERNBASE,%edi 2603384Srgrimes movl $MAXPATHLEN,%ecx /* Brute force!!! */ 2613384Srgrimes cld 2623384Srgrimes rep 2633384Srgrimes movsb 2643384Srgrimes 2653384Srgrimes1: 2663426Srgrimes#ifdef NFS 2673384Srgrimes /* 2683384Srgrimes * If we have a nfs_diskless structure copy it in 2693384Srgrimes */ 2703384Srgrimes movl BOOTINFO_NFS_DISKLESS(%ebx),%esi 2713384Srgrimes cmpl $0,%esi 2723384Srgrimes je 2f 2733384Srgrimes lea _nfs_diskless-KERNBASE,%edi 2743384Srgrimes movl $NFSDISKLESS_SIZE,%ecx 2753384Srgrimes cld 2763384Srgrimes rep 2773384Srgrimes movsb 2783795Sphk lea _nfs_diskless_valid-KERNBASE,%edi 2793795Sphk movl $1,(%edi) 2803406Sdg#endif 2813384Srgrimes 2823384Srgrimes /* 2833284Srgrimes * The old style disk boot. 2843284Srgrimes * (*btext)(howto, bootdev, cyloffset, esym); 2853384Srgrimes * Note that the newer boot code just falls into here to pick 2863384Srgrimes * up howto and bootdev, cyloffset and esym are no longer used 2873284Srgrimes */ 2883284Srgrimes2: /* olddiskboot: */ 2893384Srgrimes movl 8(%ebp),%eax 290570Srgrimes movl %eax,_boothowto-KERNBASE 2913384Srgrimes movl 12(%ebp),%eax 292570Srgrimes movl %eax,_bootdev-KERNBASE 2932783Ssos 2943489Sphk#if NAPM > 0 2953258Sdg /* 2963258Sdg * Setup APM BIOS: 2973258Sdg * 2983258Sdg * APM BIOS initialization should be done from real mode or V86 mode. 2993258Sdg * 3003258Sdg * (by HOSOKAWA, Tatsumi <hosokawa@mt.cs.keio.ac.jp>) 3013258Sdg */ 3024Srgrimes 3033258Sdg /* 3043258Sdg * Copy APM initializer under 1MB boundary: 3053258Sdg * 3063258Sdg * APM initializer program must switch the CPU to real mode. 3073258Sdg * But FreeBSD kernel runs above 1MB boundary. So we must 3083258Sdg * copy the initializer code to conventional memory. 3093258Sdg */ 3103258Sdg movl _apm_init_image_size-KERNBASE, %ecx /* size */ 3113258Sdg lea _apm_init_image-KERNBASE, %esi /* source */ 3123258Sdg movl $ APM_OURADDR, %edi /* destination */ 3133258Sdg cld 3143258Sdg rep 3153258Sdg movsb 3163258Sdg 3173258Sdg /* get GDT base */ 3183258Sdg sgdt _apm_current_gdt_pdesc-KERNBASE 3193258Sdg 3203258Sdg /* copy GDT to _bootstrap_gdt */ 3213258Sdg xorl %ecx, %ecx 3223258Sdg movw _apm_current_gdt_pdesc-KERNBASE, %cx 3233258Sdg movl _apm_current_gdt_pdesc-KERNBASE+2, %esi 3243258Sdg lea _bootstrap_gdt-KERNBASE, %edi 3253258Sdg cld 3263258Sdg rep 3273258Sdg movsb 3283258Sdg 3293258Sdg /* setup GDT pseudo descriptor */ 3303258Sdg movw $(SIZEOF_GDT*BOOTSTRAP_GDT_NUM), %ax 3313258Sdg movw %ax, _apm_current_gdt_pdesc-KERNBASE 3323258Sdg leal _bootstrap_gdt-KERNBASE, %eax 3333258Sdg movl %eax, _apm_current_gdt_pdesc-KERNBASE+2 3343258Sdg 3353258Sdg /* load new GDTR */ 3363258Sdg lgdt _apm_current_gdt_pdesc-KERNBASE 3373258Sdg 3383258Sdg /* setup GDT for APM initializer */ 3393258Sdg lea _bootstrap_gdt-KERNBASE, %ecx 3403258Sdg movl $(APM_OURADDR), %eax /* use %ax for 15..0 */ 3413258Sdg movl %eax, %ebx 3423258Sdg shrl $16, %ebx /* use %bl for 23..16 */ 3433258Sdg /* use %bh for 31..24 */ 3443258Sdg#define APM_SETUP_GDT(index, attrib) \ 3453258Sdg movl $(index), %si ; \ 3463258Sdg lea 0(%ecx,%esi,8), %edx ; \ 3473258Sdg movw $0xffff, (%edx) ; \ 3483258Sdg movw %ax, 2(%edx) ; \ 3493258Sdg movb %bl, 4(%edx) ; \ 3503258Sdg movw $(attrib), 5(%edx) ; \ 3513258Sdg movb %bh, 7(%edx) 3523258Sdg 3533258Sdg APM_SETUP_GDT(APM_INIT_CS_INDEX , CS32_ATTRIB) 3543258Sdg APM_SETUP_GDT(APM_INIT_DS_INDEX , DS32_ATTRIB) 3553258Sdg APM_SETUP_GDT(APM_INIT_CS16_INDEX, CS16_ATTRIB) 3563258Sdg 3573258Sdg /* 3583258Sdg * Call the initializer: 3593258Sdg * 3603258Sdg * direct intersegment call to conventional memory code 3613258Sdg */ 3623258Sdg .byte 0x9a /* actually, lcall $APM_INIT_CS_SEL, $0 */ 3633258Sdg .long 0 3643258Sdg .word APM_INIT_CS_SEL 3653258Sdg 3663258Sdg movw %ax, _apm_version-KERNBASE 3673258Sdg movl %ebx, _apm_cs_entry-KERNBASE 3683258Sdg movw %cx, _apm_cs32_base-KERNBASE 3693258Sdg shrl $16, %ecx 3703258Sdg movw %cx, _apm_cs16_base-KERNBASE 3713258Sdg movw %dx, _apm_ds_base-KERNBASE 3723258Sdg movw %si, _apm_cs_limit-KERNBASE 3733258Sdg shrl $16, %esi 3743258Sdg movw %si, _apm_ds_limit-KERNBASE 3753258Sdg movw %di, _apm_flags-KERNBASE 3763489Sphk#endif /* NAPM */ 3773258Sdg 3781998Swollman /* Find out our CPU type. */ 3791321Sdg 3801998Swollman /* Try to toggle alignment check flag; does not exist on 386. */ 3811998Swollman pushfl 3821998Swollman popl %eax 3831998Swollman movl %eax,%ecx 3841998Swollman orl $PSL_AC,%eax 3851998Swollman pushl %eax 3861998Swollman popfl 3871998Swollman pushfl 3881998Swollman popl %eax 3891998Swollman xorl %ecx,%eax 3901998Swollman andl $PSL_AC,%eax 3911998Swollman pushl %ecx 3921998Swollman popfl 3931998Swollman 3941998Swollman testl %eax,%eax 3951998Swollman jnz 1f 3961998Swollman movl $CPU_386,_cpu-KERNBASE 397556Srgrimes jmp 2f 3981998Swollman 3991998Swollman1: /* Try to toggle identification flag; does not exist on early 486s. */ 4001998Swollman pushfl 4011998Swollman popl %eax 4021998Swollman movl %eax,%ecx 4031998Swollman xorl $PSL_ID,%eax 4041998Swollman pushl %eax 4051998Swollman popfl 4061998Swollman pushfl 4071998Swollman popl %eax 4081998Swollman xorl %ecx,%eax 4091998Swollman andl $PSL_ID,%eax 4101998Swollman pushl %ecx 4111998Swollman popfl 4121998Swollman 4131998Swollman testl %eax,%eax 4141998Swollman jnz 1f 4151998Swollman movl $CPU_486,_cpu-KERNBASE 4162495Spst 4172495Spst /* check for Cyrix 486DLC -- based on check routine */ 4182495Spst /* documented in "Cx486SLC/e SMM Programmer's Guide" */ 4192495Spst xorw %dx,%dx 4202495Spst cmpw %dx,%dx # set flags to known state 4212495Spst pushfw 4222495Spst popw %cx # store flags in ecx 4232495Spst movw $0xffff,%ax 4242495Spst movw $0x0004,%bx 4252495Spst divw %bx 4262495Spst pushfw 4272495Spst popw %ax 4282495Spst andw $0x08d5,%ax # mask off important bits 4292495Spst andw $0x08d5,%cx 4302495Spst cmpw %ax,%cx 4312495Spst 4322495Spst jnz 2f # if flags changed, Intel chip 4332495Spst 4342495Spst movl $CPU_486DLC,_cpu-KERNBASE # set CPU value for Cyrix 4352495Spst movl $0x69727943,_cpu_vendor-KERNBASE # store vendor string 4362495Spst movw $0x0078,_cpu_vendor-KERNBASE+4 4372495Spst 4382495Spst invd # Start with guaranteed clean cache 4392495Spst /* Disable caching of the ISA hole only. */ 4402495Spst movb $CCR0,%al # Configuration Register index (CCR0) 4412495Spst outb %al,$0x22 4422495Spst inb $0x23,%al 4433117Spst orb $(CCR0_NC1|CCR0_BARB),%al 4442495Spst outb %al,$0x23 4452495Spst invd 4461998Swollman jmp 2f 4471998Swollman 4481998Swollman1: /* Use the `cpuid' instruction. */ 4491998Swollman xorl %eax,%eax 4501998Swollman .byte 0x0f,0xa2 # cpuid 0 4511998Swollman movl %ebx,_cpu_vendor-KERNBASE # store vendor string 4521998Swollman movl %edx,_cpu_vendor+4-KERNBASE 4531998Swollman movl %ecx,_cpu_vendor+8-KERNBASE 4541998Swollman movb $0,_cpu_vendor+12-KERNBASE 4551998Swollman 4561998Swollman movl $1,%eax 4571998Swollman .byte 0x0f,0xa2 # cpuid 1 4581998Swollman movl %eax,_cpu_id-KERNBASE # store cpu_id 4591998Swollman rorl $8,%eax # extract family type 4601998Swollman andl $15,%eax 4611998Swollman cmpl $5,%eax 4621998Swollman jae 1f 4631998Swollman 4641998Swollman /* less than Pentium; must be 486 */ 4651998Swollman movl $CPU_486,_cpu-KERNBASE 4661998Swollman jmp 2f 4671998Swollman 4681998Swollman1: movl $CPU_586,_cpu-KERNBASE 469556Srgrimes2: 470556Srgrimes 4714Srgrimes /* 4724Srgrimes * Finished with old stack; load new %esp now instead of later so 4734Srgrimes * we can trace this code without having to worry about the trace 4744Srgrimes * trap clobbering the memory test or the zeroing of the bss+bootstrap 4754Srgrimes * page tables. 4764Srgrimes * 4774Srgrimes * XXX - wdboot clears the bss after testing that this is safe. 4784Srgrimes * This is too wasteful - memory below 640K is scarce. The boot 4794Srgrimes * program should check: 4804Srgrimes * text+data <= &stack_variable - more_space_for_stack 4814Srgrimes * text+data+bss+pad+space_for_page_tables <= end_of_memory 4824Srgrimes * Oops, the gdt is in the carcass of the boot program so clearing 4834Srgrimes * the rest of memory is still not possible. 4844Srgrimes */ 485757Sdg movl $tmpstk-KERNBASE,%esp /* bootstrap stack end location */ 4864Srgrimes 487570Srgrimes/* 488570Srgrimes * Virtual address space of kernel: 489570Srgrimes * 490570Srgrimes * text | data | bss | [syms] | page dir | proc0 kernel stack | usr stk map | Sysmap 491974Sdg * pages: 1 UPAGES (2) 1 NKPT (7) 492570Srgrimes */ 493570Srgrimes 4944Srgrimes/* find end of kernel image */ 495570Srgrimes movl $_end-KERNBASE,%ecx 496757Sdg addl $NBPG-1,%ecx /* page align up */ 4974Srgrimes andl $~(NBPG-1),%ecx 4981321Sdg movl %ecx,%esi /* esi = start of free memory */ 499757Sdg movl %ecx,_KERNend-KERNBASE /* save end of kernel */ 5004Srgrimes 501757Sdg/* clear bss */ 502570Srgrimes movl $_edata-KERNBASE,%edi 503760Srgrimes subl %edi,%ecx /* get amount to clear */ 504757Sdg xorl %eax,%eax /* specify zero fill */ 5054Srgrimes cld 5064Srgrimes rep 5074Srgrimes stosb 5084Srgrimes 509608Srgrimes/* 510974Sdg * The value in esi is both the end of the kernel bss and a pointer to 511974Sdg * the kernel page directory, and is used by the rest of locore to build 512974Sdg * the tables. 513974Sdg * esi + 1(page dir) + 2(UPAGES) + 1(p0stack) + NKPT(number of kernel 514757Sdg * page table pages) is then passed on the stack to init386(first) as 515757Sdg * the value first. esi should ALWAYS be page aligned!! 516608Srgrimes */ 517757Sdg movl %esi,%ecx /* Get current first availiable address */ 518608Srgrimes 519757Sdg/* clear pagetables, page directory, stack, etc... */ 520757Sdg movl %esi,%edi /* base (page directory) */ 521974Sdg movl $((1+UPAGES+1+NKPT)*NBPG),%ecx /* amount to clear */ 522757Sdg xorl %eax,%eax /* specify zero fill */ 523757Sdg cld 524757Sdg rep 525757Sdg stosb 526757Sdg 527757Sdg/* physical address of Idle proc/kernel page directory */ 528570Srgrimes movl %esi,_IdlePTD-KERNBASE 5294Srgrimes 530592Srgrimes/* 531592Srgrimes * fillkpt 532592Srgrimes * eax = (page frame address | control | status) == pte 533592Srgrimes * ebx = address of page table 534592Srgrimes * ecx = how many pages to map 535592Srgrimes */ 5364Srgrimes#define fillkpt \ 5374Srgrimes1: movl %eax,(%ebx) ; \ 538570Srgrimes addl $NBPG,%eax ; /* increment physical address */ \ 5394Srgrimes addl $4,%ebx ; /* next pte */ \ 5404Srgrimes loop 1b ; 5414Srgrimes 5424Srgrimes/* 5434Srgrimes * Map Kernel 5444Srgrimes * 5454Srgrimes * First step - build page tables 5464Srgrimes */ 547757Sdg#if defined (KGDB) || defined (BDE_DEBUGGER) 548757Sdg movl _KERNend-KERNBASE,%ecx /* this much memory, */ 549757Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 550757Sdg#ifdef BDE_DEBUGGER 551757Sdg cmpl $0xa0,%ecx /* XXX - cover debugger pages */ 552200Sdg jae 1f 553200Sdg movl $0xa0,%ecx 554200Sdg1: 555757Sdg#endif /* BDE_DEBUGGER */ 5562512Sbde movl $PG_V|PG_KW,%eax /* kernel R/W, valid */ 557757Sdg lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 558757Sdg movl %ebx,_KPTphys-KERNBASE /* save in global */ 5594Srgrimes fillkpt 5604Srgrimes 561757Sdg#else /* !KGDB && !BDE_DEBUGGER */ 562757Sdg /* write protect kernel text (doesn't do a thing for 386's - only 486's) */ 563757Sdg movl $_etext-KERNBASE,%ecx /* get size of text */ 5643842Sdg addl $NBPG-1,%ecx /* round up to page */ 565757Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 566757Sdg movl $PG_V|PG_KR,%eax /* specify read only */ 5673842Sdg#if 0 5683842Sdg movl $_etext,%ecx /* get size of text */ 5693842Sdg subl $_btext,%ecx 5703842Sdg addl $NBPG-1,%ecx /* round up to page */ 5713842Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 5723842Sdg movl $_btext-KERNBASE,%eax /* get offset to physical memory */ 5733842Sdg orl $PG_V|PG_KR,%eax /* specify read only */ 5743842Sdg#endif 575757Sdg lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 576757Sdg movl %ebx,_KPTphys-KERNBASE /* save in global */ 577757Sdg fillkpt 578757Sdg 579757Sdg /* data and bss are r/w */ 580757Sdg andl $PG_FRAME,%eax /* strip to just addr of bss */ 581757Sdg movl _KERNend-KERNBASE,%ecx /* calculate size */ 582757Sdg subl %eax,%ecx 583757Sdg shrl $PGSHIFT,%ecx 584757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 585757Sdg fillkpt 5861321Sdg#endif /* KGDB || BDE_DEBUGGER */ 587757Sdg 588757Sdg/* now initialize the page dir, upages, p0stack PT, and page tables */ 589757Sdg 590974Sdg movl $(1+UPAGES+1+NKPT),%ecx /* number of PTEs */ 591757Sdg movl %esi,%eax /* phys address of PTD */ 592757Sdg andl $PG_FRAME,%eax /* convert to PFN, should be a NOP */ 5932512Sbde orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 594757Sdg movl %esi,%ebx /* calculate pte offset to ptd */ 595757Sdg shrl $PGSHIFT-2,%ebx 596757Sdg addl %esi,%ebx /* address of page directory */ 597757Sdg addl $((1+UPAGES+1)*NBPG),%ebx /* offset to kernel page tables */ 598757Sdg fillkpt 5991321Sdg 6004Srgrimes/* map I/O memory map */ 6014Srgrimes 602757Sdg movl _KPTphys-KERNBASE,%ebx /* base of kernel page tables */ 603757Sdg lea (0xa0 * PTESIZE)(%ebx),%ebx /* hardwire ISA hole at KERNBASE + 0xa0000 */ 604757Sdg movl $0x100-0xa0,%ecx /* for this many pte s, */ 6051046Sdg movl $(0xa0000|PG_V|PG_KW|PG_N),%eax /* valid, kernel read/write, non-cacheable */ 606757Sdg movl %ebx,_atdevphys-KERNBASE /* save phys addr of ptes */ 6074Srgrimes fillkpt 6084Srgrimes 6094Srgrimes /* map proc 0's kernel stack into user page table page */ 6104Srgrimes 611757Sdg movl $UPAGES,%ecx /* for this many pte s, */ 612757Sdg lea (1*NBPG)(%esi),%eax /* physical address in proc 0 */ 613757Sdg lea (KERNBASE)(%eax),%edx /* change into virtual addr */ 614757Sdg movl %edx,_proc0paddr-KERNBASE /* save VA for proc 0 init */ 615757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 616757Sdg lea ((1+UPAGES)*NBPG)(%esi),%ebx /* addr of stack page table in proc 0 */ 617757Sdg addl $(KSTKPTEOFF * PTESIZE),%ebx /* offset to kernel stack PTE */ 6184Srgrimes fillkpt 6194Srgrimes 6204Srgrimes/* 621757Sdg * Initialize kernel page table directory 6224Srgrimes */ 6234Srgrimes /* install a pde for temporary double map of bottom of VA */ 624757Sdg movl _KPTphys-KERNBASE,%eax 625757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 626757Sdg movl %eax,(%esi) /* which is where temp maps! */ 6274Srgrimes 628757Sdg /* initialize kernel pde's */ 629974Sdg movl $(NKPT),%ecx /* for this many PDEs */ 630757Sdg lea (KPTDI*PDESIZE)(%esi),%ebx /* offset of pde for kernel */ 6314Srgrimes fillkpt 6324Srgrimes 6334Srgrimes /* install a pde recursively mapping page directory as a page table! */ 634757Sdg movl %esi,%eax /* phys address of ptd in proc 0 */ 635757Sdg orl $PG_V|PG_KW,%eax /* pde entry is valid */ 636757Sdg movl %eax,PTDPTDI*PDESIZE(%esi) /* which is where PTmap maps! */ 6374Srgrimes 6384Srgrimes /* install a pde to map kernel stack for proc 0 */ 639757Sdg lea ((1+UPAGES)*NBPG)(%esi),%eax /* physical address of pt in proc 0 */ 640757Sdg orl $PG_V|PG_KW,%eax /* pde entry is valid */ 641757Sdg movl %eax,KSTKPTDI*PDESIZE(%esi) /* which is where kernel stack maps! */ 6424Srgrimes 643757Sdg#ifdef BDE_DEBUGGER 6444Srgrimes /* copy and convert stuff from old gdt and idt for debugger */ 6454Srgrimes 646757Sdg cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 6474Srgrimes jne 1f 648570Srgrimes movb $1,_bdb_exists-KERNBASE 6494Srgrimes1: 6504Srgrimes pushal 6514Srgrimes subl $2*6,%esp 6524Srgrimes 6534Srgrimes sgdt (%esp) 654757Sdg movl 2(%esp),%esi /* base address of current gdt */ 655570Srgrimes movl $_gdt-KERNBASE,%edi 6564Srgrimes movl %edi,2(%esp) 6574Srgrimes movl $8*18/4,%ecx 6581688Sdg cld 659757Sdg rep /* copy gdt */ 6604Srgrimes movsl 661570Srgrimes movl $_gdt-KERNBASE,-8+2(%edi) /* adjust gdt self-ptr */ 6624Srgrimes movb $0x92,-8+5(%edi) 6634Srgrimes 6644Srgrimes sidt 6(%esp) 665757Sdg movl 6+2(%esp),%esi /* base address of current idt */ 666757Sdg movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 6674Srgrimes movw 8(%esi),%ax 668570Srgrimes movl %eax,bdb_dbg_ljmp+1-KERNBASE /* ... immediate offset ... */ 6694Srgrimes movl 8+2(%esi),%eax 670570Srgrimes movw %ax,bdb_dbg_ljmp+5-KERNBASE /* ... and selector for ljmp */ 671757Sdg movl 24+4(%esi),%eax /* same for bpt descriptor */ 6724Srgrimes movw 24(%esi),%ax 673570Srgrimes movl %eax,bdb_bpt_ljmp+1-KERNBASE 6744Srgrimes movl 24+2(%esi),%eax 675570Srgrimes movw %ax,bdb_bpt_ljmp+5-KERNBASE 6764Srgrimes 677570Srgrimes movl $_idt-KERNBASE,%edi 6784Srgrimes movl %edi,6+2(%esp) 6794Srgrimes movl $8*4/4,%ecx 6801688Sdg cld 681757Sdg rep /* copy idt */ 6824Srgrimes movsl 6834Srgrimes 6844Srgrimes lgdt (%esp) 6854Srgrimes lidt 6(%esp) 6864Srgrimes 6874Srgrimes addl $2*6,%esp 6884Srgrimes popal 6891321Sdg#endif /* BDE_DEBUGGER */ 6904Srgrimes 691592Srgrimes /* load base of page directory and enable mapping */ 692757Sdg movl %esi,%eax /* phys address of ptd in proc 0 */ 693757Sdg movl %eax,%cr3 /* load ptd addr into mmu */ 694757Sdg movl %cr0,%eax /* get control word */ 695757Sdg orl $CR0_PE|CR0_PG,%eax /* enable paging */ 696757Sdg movl %eax,%cr0 /* and let's page NOW! */ 6974Srgrimes 698757Sdg pushl $begin /* jump to high mem */ 6994Srgrimes ret 7004Srgrimes 701570Srgrimesbegin: /* now running relocated at KERNBASE where the system is linked to run */ 702757Sdg movl _atdevphys,%edx /* get pte PA */ 703757Sdg subl _KPTphys,%edx /* remove base of ptes, now have phys offset */ 704757Sdg shll $PGSHIFT-2,%edx /* corresponding to virt offset */ 705757Sdg addl $KERNBASE,%edx /* add virtual base */ 706570Srgrimes movl %edx,_atdevbase 7073728Sphk 7083861Sbde#include "sc.h" 7094031Sjoerg#include "vt.h" 7104031Sjoerg#if NSC > 0 || NVT > 0 7113728Sphk /* XXX: can't scinit relocate Crtat relative to atdevbase itself? */ 7123728Sphk .globl _Crtat /* XXX - locore should not know about */ 7133728Sphk movl _Crtat,%eax /* variables of device drivers (pccons)! */ 7143728Sphk subl $(KERNBASE+0xA0000),%eax 7154Srgrimes addl %eax,%edx 7164Srgrimes movl %edx,_Crtat 7173728Sphk#endif 7184Srgrimes 719757Sdg /* set up bootstrap stack - 48 bytes */ 720570Srgrimes movl $_kstack+UPAGES*NBPG-4*12,%esp /* bootstrap stack end location */ 721757Sdg xorl %eax,%eax /* mark end of frames */ 7224Srgrimes movl %eax,%ebp 723570Srgrimes movl _proc0paddr,%eax 724570Srgrimes movl %esi,PCB_CR3(%eax) 7254Srgrimes 726757Sdg#ifdef BDE_DEBUGGER 7274Srgrimes /* relocate debugger gdt entries */ 7284Srgrimes 729757Sdg movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 7304Srgrimes movl $9,%ecx 7314Srgrimesreloc_gdt: 7321321Sdg movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 733757Sdg addl $8,%eax /* now KERNBASE>>24 */ 7344Srgrimes loop reloc_gdt 7354Srgrimes 7364Srgrimes cmpl $0,_bdb_exists 7374Srgrimes je 1f 7384Srgrimes int $3 7394Srgrimes1: 7401321Sdg#endif /* BDE_DEBUGGER */ 7414Srgrimes 742608Srgrimes /* 743608Srgrimes * Skip over the page tables and the kernel stack 744608Srgrimes */ 745974Sdg lea ((1+UPAGES+1+NKPT)*NBPG)(%esi),%esi 746608Srgrimes 747757Sdg pushl %esi /* value of first for init386(first) */ 748757Sdg call _init386 /* wire 386 chip for unix operation */ 7491549Srgrimes popl %esi 750200Sdg 7511549Srgrimes .globl __ucodesel,__udatasel 7521549Srgrimes 7531549Srgrimes pushl $0 /* unused */ 7541549Srgrimes pushl __udatasel /* ss */ 7551549Srgrimes pushl $0 /* esp - filled in by execve() */ 7562500Sdg pushl $PSL_USERSET /* eflags (ring 0, int enab) */ 7571549Srgrimes pushl __ucodesel /* cs */ 7581549Srgrimes pushl $0 /* eip - filled in by execve() */ 7591549Srgrimes subl $(12*4),%esp /* space for rest of registers */ 7601549Srgrimes 7611549Srgrimes pushl %esp /* call main with frame pointer */ 762757Sdg call _main /* autoconfiguration, mountroot etc */ 7634Srgrimes 7641549Srgrimes addl $(13*4),%esp /* back to a frame we can return with */ 7651549Srgrimes 766134Sdg /* 767570Srgrimes * now we've run main() and determined what cpu-type we are, we can 768570Srgrimes * enable WP mode on i486 cpus and above. 7691058Sdg */ 7701058Sdg#if defined(I486_CPU) || defined(I586_CPU) 7711058Sdg cmpl $CPUCLASS_386,_cpu_class 7721058Sdg je 1f 7731058Sdg movl %cr0,%eax /* get control word */ 7741058Sdg orl $CR0_WP,%eax /* enable write protect for all modes */ 7751058Sdg movl %eax,%cr0 /* and do it */ 7761058Sdg#endif 7771058Sdg /* 778134Sdg * on return from main(), we are process 1 779134Sdg * set up address space and stack so that we can 'return' to user mode 780134Sdg */ 7811058Sdg1: 7824Srgrimes movl __ucodesel,%eax 7834Srgrimes movl __udatasel,%ecx 7841549Srgrimes 7854Srgrimes movl %cx,%ds 7864Srgrimes movl %cx,%es 787757Sdg movl %ax,%fs /* double map cs to fs */ 788757Sdg movl %cx,%gs /* and ds to gs */ 7891549Srgrimes iret /* goto user! */ 7904Srgrimes 7911549Srgrimes#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 7924Srgrimes 793200SdgNON_GPROF_ENTRY(sigcode) 794592Srgrimes call SIGF_HANDLER(%esp) 795757Sdg lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 796757Sdg /* copy at 8(%esp)) */ 7974Srgrimes pushl %eax 798757Sdg pushl %eax /* junk to fake return address */ 799757Sdg movl $103,%eax /* XXX sigreturn() */ 800757Sdg LCALL(0x7,0) /* enter kernel with args on stack */ 801757Sdg hlt /* never gets here */ 8024Srgrimes 8034Srgrimes .globl _szsigcode 8044Srgrimes_szsigcode: 8054Srgrimes .long _szsigcode-_sigcode 806