locore.s revision 3861
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 373861Sbde * $Id: locore.s,v 1.39 1994/10/25 07:25:55 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 "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: 1113842Sdg .long 0 /* for debugging tmpstk stack underflow */ 1123842Sdg 1133861Sbde .globl _boothowto,_bootdev 114134Sdg 1151998Swollman .globl _cpu,_cold,_atdevbase,_cpu_vendor,_cpu_id 1162783Ssos 1172783Ssos .globl _video_mode_ptr 1182783Ssos 119757Sdg_cpu: .long 0 /* are we 386, 386sx, or 486 */ 1202216Sbde_cpu_id: .long 0 /* stepping ID */ 1212216Sbde_cpu_vendor: .space 20 /* CPU origin code */ 1222783Ssos_video_mode_ptr: .long 0 123757Sdg_cold: .long 1 /* cold till we are not */ 124757Sdg_atdevbase: .long 0 /* location of start of iomem in virtual */ 125757Sdg_atdevphys: .long 0 /* location of device mapping ptes (phys) */ 1264Srgrimes 127757Sdg_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 128757Sdg 1293861Sbde .globl _IdlePTD 130757Sdg_IdlePTD: .long 0 /* phys addr of kernel PTD */ 1313861Sbde 132757Sdg_KPTphys: .long 0 /* phys addr of kernel page tables */ 1334Srgrimes 134757Sdg .globl _proc0paddr 135757Sdg_proc0paddr: .long 0 /* address of proc 0 address space */ 136134Sdg 137757Sdg#ifdef BDE_DEBUGGER 138757Sdg .globl _bdb_exists /* flag to indicate BDE debugger is available */ 1391321Sdg_bdb_exists: .long 0 140757Sdg#endif 1413489Sphk#if NAPM > 0 1423258Sdg .globl _apm_current_gdt_pdesc /* current GDT pseudo desc. */ 1433258Sdg_apm_current_gdt_pdesc: 1443314Sdg .word 0, 0, 0 145718Swollman 1463258Sdg .globl _bootstrap_gdt 1473258Sdg_bootstrap_gdt: 1483258Sdg .space SIZEOF_GDT * BOOTSTRAP_GDT_NUM 1493489Sphk#endif /* NAPM */ 150134Sdg 151556Srgrimes/* 152556Srgrimes * System Initialization 153556Srgrimes */ 1544Srgrimes .text 155134Sdg 156134Sdg/* 157200Sdg * btext: beginning of text section. 158200Sdg * Also the entry point (jumped to directly from the boot blocks). 159134Sdg */ 1601321SdgNON_GPROF_ENTRY(btext) 161757Sdg movw $0x1234,0x472 /* warm boot */ 1624Srgrimes jmp 1f 1633284Srgrimes /* 1643284Srgrimes * XXX now that we load at 1MB is this still really used? 1653284Srgrimes */ 1661321Sdg .org 0x500 /* space for BIOS variables */ 1674Srgrimes 1683284Srgrimes1: 1693384Srgrimes /* Set up a real frame, some day we will be doing returns */ 1703384Srgrimes pushl %ebp 1713384Srgrimes movl %esp, %ebp 1723384Srgrimes 1732512Sbde /* Don't trust what the BIOS gives for eflags. */ 1742512Sbde pushl $PSL_MBO 1752486Sdg popfl 1762486Sdg 1774Srgrimes /* 1783284Srgrimes * This code is called in different ways depending on what loaded 1793284Srgrimes * and started the kernel. This is used to detect how we get the 1803284Srgrimes * arguments from the other code and what we do with them. 1813284Srgrimes * 1823284Srgrimes * Old disk boot blocks: 1833284Srgrimes * (*btext)(howto, bootdev, cyloffset, esym); 1843284Srgrimes * [return address == 0, and can NOT be returned to] 1853284Srgrimes * [cyloffset was not supported by the FreeBSD boot code 1863284Srgrimes * and always passed in as 0] 1873284Srgrimes * [esym is also known as total in the boot code, and 1883284Srgrimes * was never properly supported by the FreeBSD boot code] 1893284Srgrimes * 1903284Srgrimes * Old diskless netboot code: 1913284Srgrimes * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 1923284Srgrimes * [return address != 0, and can NOT be returned to] 1933284Srgrimes * If we are being booted by this code it will NOT work, 1943284Srgrimes * so we are just going to halt if we find this case. 1953284Srgrimes * 1963284Srgrimes * New uniform boot code: 1973284Srgrimes * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 1983284Srgrimes * [return address != 0, and can be returned to] 1993284Srgrimes * 2003284Srgrimes * There may seem to be a lot of wasted arguments in here, but 2013384Srgrimes * that is so the newer boot code can still load very old kernels 2023384Srgrimes * and old boot code can load new kernels. 2034Srgrimes */ 2043284Srgrimes 2053284Srgrimes /* 2063284Srgrimes * The old style disk boot blocks fake a frame on the stack and 2073284Srgrimes * did an lret to get here. The frame on the stack has a return 2083284Srgrimes * address of 0. 2093284Srgrimes */ 2103384Srgrimes cmpl $0,4(%ebp) 2113284Srgrimes je 2f /* olddiskboot: */ 2123284Srgrimes 2133284Srgrimes /* 2143284Srgrimes * We have some form of return address, so this is either the 2153284Srgrimes * old diskless netboot code, or the new uniform code. That can 2163284Srgrimes * be detected by looking at the 5th argument, it if is 0 we 2173284Srgrimes * we are being booted by the new unifrom boot code. 2183284Srgrimes */ 2193384Srgrimes cmpl $0,24(%ebp) 2203284Srgrimes je 1f /* newboot: */ 2213284Srgrimes 2223284Srgrimes /* 2233284Srgrimes * Seems we have been loaded by the old diskless boot code, we 2243284Srgrimes * don't stand a chance of running as the diskless structure 2253284Srgrimes * changed considerably between the two, so just halt. 2263284Srgrimes */ 2273284Srgrimes hlt 2283284Srgrimes 2293284Srgrimes /* 2303384Srgrimes * We have been loaded by the new uniform boot code. 2313384Srgrimes * Lets check the bootinfo version, and if we do not understand 2323384Srgrimes * it we return to the loader with a status of 1 to indicate this error 2333284Srgrimes */ 2343284Srgrimes1: /* newboot: */ 2353384Srgrimes movl 28(%ebp),%ebx /* &bootinfo.version */ 2363384Srgrimes movl BOOTINFO_VERSION(%ebx),%eax 2373384Srgrimes cmpl $1,%eax /* We only understand version 1 */ 2383384Srgrimes je 1f 2393384Srgrimes movl $1,%eax /* Return status */ 2403384Srgrimes leave 2413384Srgrimes ret 2423284Srgrimes 2433384Srgrimes1: 2443284Srgrimes /* 2453384Srgrimes * If we have a kernelname copy it in 2463384Srgrimes */ 2473384Srgrimes movl BOOTINFO_KERNELNAME(%ebx),%esi 2483384Srgrimes cmpl $0,%esi 2493384Srgrimes je 1f /* No kernelname */ 2503384Srgrimes lea _kernelname-KERNBASE,%edi 2513384Srgrimes movl $MAXPATHLEN,%ecx /* Brute force!!! */ 2523384Srgrimes cld 2533384Srgrimes rep 2543384Srgrimes movsb 2553384Srgrimes 2563384Srgrimes1: 2573426Srgrimes#ifdef NFS 2583384Srgrimes /* 2593384Srgrimes * If we have a nfs_diskless structure copy it in 2603384Srgrimes */ 2613384Srgrimes movl BOOTINFO_NFS_DISKLESS(%ebx),%esi 2623384Srgrimes cmpl $0,%esi 2633384Srgrimes je 2f 2643384Srgrimes lea _nfs_diskless-KERNBASE,%edi 2653384Srgrimes movl $NFSDISKLESS_SIZE,%ecx 2663384Srgrimes cld 2673384Srgrimes rep 2683384Srgrimes movsb 2693795Sphk lea _nfs_diskless_valid-KERNBASE,%edi 2703795Sphk movl $1,(%edi) 2713406Sdg#endif 2723384Srgrimes 2733384Srgrimes /* 2743284Srgrimes * The old style disk boot. 2753284Srgrimes * (*btext)(howto, bootdev, cyloffset, esym); 2763384Srgrimes * Note that the newer boot code just falls into here to pick 2773384Srgrimes * up howto and bootdev, cyloffset and esym are no longer used 2783284Srgrimes */ 2793284Srgrimes2: /* olddiskboot: */ 2803384Srgrimes movl 8(%ebp),%eax 281570Srgrimes movl %eax,_boothowto-KERNBASE 2823384Srgrimes movl 12(%ebp),%eax 283570Srgrimes movl %eax,_bootdev-KERNBASE 2842783Ssos 2852783Ssos /* get the BIOS video mode pointer */ 2862783Ssos movl $0x4a8, %ecx 2872783Ssos movl (%ecx), %eax 2882783Ssos movl %eax, %ecx 2892783Ssos shrl $12, %ecx 2902783Ssos andl $0xffff0000, %ecx 2912783Ssos andl $0x0000ffff, %eax 2922783Ssos orl %ecx, %eax 2932783Ssos movl (%eax), %eax 2942783Ssos movl %eax, %ecx 2952783Ssos shrl $12, %ecx 2962783Ssos andl $0xffff0000, %ecx 2972783Ssos andl $0x0000ffff, %eax 2982783Ssos orl %ecx, %eax 2992783Ssos addl $KERNBASE, %eax 3002783Ssos movl %eax, _video_mode_ptr-KERNBASE 3012783Ssos 3023489Sphk#if NAPM > 0 3033258Sdg /* 3043258Sdg * Setup APM BIOS: 3053258Sdg * 3063258Sdg * APM BIOS initialization should be done from real mode or V86 mode. 3073258Sdg * 3083258Sdg * (by HOSOKAWA, Tatsumi <hosokawa@mt.cs.keio.ac.jp>) 3093258Sdg */ 3104Srgrimes 3113258Sdg /* 3123258Sdg * Copy APM initializer under 1MB boundary: 3133258Sdg * 3143258Sdg * APM initializer program must switch the CPU to real mode. 3153258Sdg * But FreeBSD kernel runs above 1MB boundary. So we must 3163258Sdg * copy the initializer code to conventional memory. 3173258Sdg */ 3183258Sdg movl _apm_init_image_size-KERNBASE, %ecx /* size */ 3193258Sdg lea _apm_init_image-KERNBASE, %esi /* source */ 3203258Sdg movl $ APM_OURADDR, %edi /* destination */ 3213258Sdg cld 3223258Sdg rep 3233258Sdg movsb 3243258Sdg 3253258Sdg /* get GDT base */ 3263258Sdg sgdt _apm_current_gdt_pdesc-KERNBASE 3273258Sdg 3283258Sdg /* copy GDT to _bootstrap_gdt */ 3293258Sdg xorl %ecx, %ecx 3303258Sdg movw _apm_current_gdt_pdesc-KERNBASE, %cx 3313258Sdg movl _apm_current_gdt_pdesc-KERNBASE+2, %esi 3323258Sdg lea _bootstrap_gdt-KERNBASE, %edi 3333258Sdg cld 3343258Sdg rep 3353258Sdg movsb 3363258Sdg 3373258Sdg /* setup GDT pseudo descriptor */ 3383258Sdg movw $(SIZEOF_GDT*BOOTSTRAP_GDT_NUM), %ax 3393258Sdg movw %ax, _apm_current_gdt_pdesc-KERNBASE 3403258Sdg leal _bootstrap_gdt-KERNBASE, %eax 3413258Sdg movl %eax, _apm_current_gdt_pdesc-KERNBASE+2 3423258Sdg 3433258Sdg /* load new GDTR */ 3443258Sdg lgdt _apm_current_gdt_pdesc-KERNBASE 3453258Sdg 3463258Sdg /* setup GDT for APM initializer */ 3473258Sdg lea _bootstrap_gdt-KERNBASE, %ecx 3483258Sdg movl $(APM_OURADDR), %eax /* use %ax for 15..0 */ 3493258Sdg movl %eax, %ebx 3503258Sdg shrl $16, %ebx /* use %bl for 23..16 */ 3513258Sdg /* use %bh for 31..24 */ 3523258Sdg#define APM_SETUP_GDT(index, attrib) \ 3533258Sdg movl $(index), %si ; \ 3543258Sdg lea 0(%ecx,%esi,8), %edx ; \ 3553258Sdg movw $0xffff, (%edx) ; \ 3563258Sdg movw %ax, 2(%edx) ; \ 3573258Sdg movb %bl, 4(%edx) ; \ 3583258Sdg movw $(attrib), 5(%edx) ; \ 3593258Sdg movb %bh, 7(%edx) 3603258Sdg 3613258Sdg APM_SETUP_GDT(APM_INIT_CS_INDEX , CS32_ATTRIB) 3623258Sdg APM_SETUP_GDT(APM_INIT_DS_INDEX , DS32_ATTRIB) 3633258Sdg APM_SETUP_GDT(APM_INIT_CS16_INDEX, CS16_ATTRIB) 3643258Sdg 3653258Sdg /* 3663258Sdg * Call the initializer: 3673258Sdg * 3683258Sdg * direct intersegment call to conventional memory code 3693258Sdg */ 3703258Sdg .byte 0x9a /* actually, lcall $APM_INIT_CS_SEL, $0 */ 3713258Sdg .long 0 3723258Sdg .word APM_INIT_CS_SEL 3733258Sdg 3743258Sdg movw %ax, _apm_version-KERNBASE 3753258Sdg movl %ebx, _apm_cs_entry-KERNBASE 3763258Sdg movw %cx, _apm_cs32_base-KERNBASE 3773258Sdg shrl $16, %ecx 3783258Sdg movw %cx, _apm_cs16_base-KERNBASE 3793258Sdg movw %dx, _apm_ds_base-KERNBASE 3803258Sdg movw %si, _apm_cs_limit-KERNBASE 3813258Sdg shrl $16, %esi 3823258Sdg movw %si, _apm_ds_limit-KERNBASE 3833258Sdg movw %di, _apm_flags-KERNBASE 3843489Sphk#endif /* NAPM */ 3853258Sdg 3861998Swollman /* Find out our CPU type. */ 3871321Sdg 3881998Swollman /* Try to toggle alignment check flag; does not exist on 386. */ 3891998Swollman pushfl 3901998Swollman popl %eax 3911998Swollman movl %eax,%ecx 3921998Swollman orl $PSL_AC,%eax 3931998Swollman pushl %eax 3941998Swollman popfl 3951998Swollman pushfl 3961998Swollman popl %eax 3971998Swollman xorl %ecx,%eax 3981998Swollman andl $PSL_AC,%eax 3991998Swollman pushl %ecx 4001998Swollman popfl 4011998Swollman 4021998Swollman testl %eax,%eax 4031998Swollman jnz 1f 4041998Swollman movl $CPU_386,_cpu-KERNBASE 405556Srgrimes jmp 2f 4061998Swollman 4071998Swollman1: /* Try to toggle identification flag; does not exist on early 486s. */ 4081998Swollman pushfl 4091998Swollman popl %eax 4101998Swollman movl %eax,%ecx 4111998Swollman xorl $PSL_ID,%eax 4121998Swollman pushl %eax 4131998Swollman popfl 4141998Swollman pushfl 4151998Swollman popl %eax 4161998Swollman xorl %ecx,%eax 4171998Swollman andl $PSL_ID,%eax 4181998Swollman pushl %ecx 4191998Swollman popfl 4201998Swollman 4211998Swollman testl %eax,%eax 4221998Swollman jnz 1f 4231998Swollman movl $CPU_486,_cpu-KERNBASE 4242495Spst 4252495Spst /* check for Cyrix 486DLC -- based on check routine */ 4262495Spst /* documented in "Cx486SLC/e SMM Programmer's Guide" */ 4272495Spst xorw %dx,%dx 4282495Spst cmpw %dx,%dx # set flags to known state 4292495Spst pushfw 4302495Spst popw %cx # store flags in ecx 4312495Spst movw $0xffff,%ax 4322495Spst movw $0x0004,%bx 4332495Spst divw %bx 4342495Spst pushfw 4352495Spst popw %ax 4362495Spst andw $0x08d5,%ax # mask off important bits 4372495Spst andw $0x08d5,%cx 4382495Spst cmpw %ax,%cx 4392495Spst 4402495Spst jnz 2f # if flags changed, Intel chip 4412495Spst 4422495Spst movl $CPU_486DLC,_cpu-KERNBASE # set CPU value for Cyrix 4432495Spst movl $0x69727943,_cpu_vendor-KERNBASE # store vendor string 4442495Spst movw $0x0078,_cpu_vendor-KERNBASE+4 4452495Spst 4462495Spst invd # Start with guaranteed clean cache 4472495Spst /* Disable caching of the ISA hole only. */ 4482495Spst movb $CCR0,%al # Configuration Register index (CCR0) 4492495Spst outb %al,$0x22 4502495Spst inb $0x23,%al 4513117Spst orb $(CCR0_NC1|CCR0_BARB),%al 4522495Spst outb %al,$0x23 4532495Spst invd 4541998Swollman jmp 2f 4551998Swollman 4561998Swollman1: /* Use the `cpuid' instruction. */ 4571998Swollman xorl %eax,%eax 4581998Swollman .byte 0x0f,0xa2 # cpuid 0 4591998Swollman movl %ebx,_cpu_vendor-KERNBASE # store vendor string 4601998Swollman movl %edx,_cpu_vendor+4-KERNBASE 4611998Swollman movl %ecx,_cpu_vendor+8-KERNBASE 4621998Swollman movb $0,_cpu_vendor+12-KERNBASE 4631998Swollman 4641998Swollman movl $1,%eax 4651998Swollman .byte 0x0f,0xa2 # cpuid 1 4661998Swollman movl %eax,_cpu_id-KERNBASE # store cpu_id 4671998Swollman rorl $8,%eax # extract family type 4681998Swollman andl $15,%eax 4691998Swollman cmpl $5,%eax 4701998Swollman jae 1f 4711998Swollman 4721998Swollman /* less than Pentium; must be 486 */ 4731998Swollman movl $CPU_486,_cpu-KERNBASE 4741998Swollman jmp 2f 4751998Swollman 4761998Swollman1: movl $CPU_586,_cpu-KERNBASE 477556Srgrimes2: 478556Srgrimes 4794Srgrimes /* 4804Srgrimes * Finished with old stack; load new %esp now instead of later so 4814Srgrimes * we can trace this code without having to worry about the trace 4824Srgrimes * trap clobbering the memory test or the zeroing of the bss+bootstrap 4834Srgrimes * page tables. 4844Srgrimes * 4854Srgrimes * XXX - wdboot clears the bss after testing that this is safe. 4864Srgrimes * This is too wasteful - memory below 640K is scarce. The boot 4874Srgrimes * program should check: 4884Srgrimes * text+data <= &stack_variable - more_space_for_stack 4894Srgrimes * text+data+bss+pad+space_for_page_tables <= end_of_memory 4904Srgrimes * Oops, the gdt is in the carcass of the boot program so clearing 4914Srgrimes * the rest of memory is still not possible. 4924Srgrimes */ 493757Sdg movl $tmpstk-KERNBASE,%esp /* bootstrap stack end location */ 4944Srgrimes 495570Srgrimes/* 496570Srgrimes * Virtual address space of kernel: 497570Srgrimes * 498570Srgrimes * text | data | bss | [syms] | page dir | proc0 kernel stack | usr stk map | Sysmap 499974Sdg * pages: 1 UPAGES (2) 1 NKPT (7) 500570Srgrimes */ 501570Srgrimes 5024Srgrimes/* find end of kernel image */ 503570Srgrimes movl $_end-KERNBASE,%ecx 504757Sdg addl $NBPG-1,%ecx /* page align up */ 5054Srgrimes andl $~(NBPG-1),%ecx 5061321Sdg movl %ecx,%esi /* esi = start of free memory */ 507757Sdg movl %ecx,_KERNend-KERNBASE /* save end of kernel */ 5084Srgrimes 509757Sdg/* clear bss */ 510570Srgrimes movl $_edata-KERNBASE,%edi 511760Srgrimes subl %edi,%ecx /* get amount to clear */ 512757Sdg xorl %eax,%eax /* specify zero fill */ 5134Srgrimes cld 5144Srgrimes rep 5154Srgrimes stosb 5164Srgrimes 517608Srgrimes/* 518974Sdg * The value in esi is both the end of the kernel bss and a pointer to 519974Sdg * the kernel page directory, and is used by the rest of locore to build 520974Sdg * the tables. 521974Sdg * esi + 1(page dir) + 2(UPAGES) + 1(p0stack) + NKPT(number of kernel 522757Sdg * page table pages) is then passed on the stack to init386(first) as 523757Sdg * the value first. esi should ALWAYS be page aligned!! 524608Srgrimes */ 525757Sdg movl %esi,%ecx /* Get current first availiable address */ 526608Srgrimes 527757Sdg/* clear pagetables, page directory, stack, etc... */ 528757Sdg movl %esi,%edi /* base (page directory) */ 529974Sdg movl $((1+UPAGES+1+NKPT)*NBPG),%ecx /* amount to clear */ 530757Sdg xorl %eax,%eax /* specify zero fill */ 531757Sdg cld 532757Sdg rep 533757Sdg stosb 534757Sdg 535757Sdg/* physical address of Idle proc/kernel page directory */ 536570Srgrimes movl %esi,_IdlePTD-KERNBASE 5374Srgrimes 538592Srgrimes/* 539592Srgrimes * fillkpt 540592Srgrimes * eax = (page frame address | control | status) == pte 541592Srgrimes * ebx = address of page table 542592Srgrimes * ecx = how many pages to map 543592Srgrimes */ 5444Srgrimes#define fillkpt \ 5454Srgrimes1: movl %eax,(%ebx) ; \ 546570Srgrimes addl $NBPG,%eax ; /* increment physical address */ \ 5474Srgrimes addl $4,%ebx ; /* next pte */ \ 5484Srgrimes loop 1b ; 5494Srgrimes 5504Srgrimes/* 5514Srgrimes * Map Kernel 5524Srgrimes * 5534Srgrimes * First step - build page tables 5544Srgrimes */ 555757Sdg#if defined (KGDB) || defined (BDE_DEBUGGER) 556757Sdg movl _KERNend-KERNBASE,%ecx /* this much memory, */ 557757Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 558757Sdg#ifdef BDE_DEBUGGER 559757Sdg cmpl $0xa0,%ecx /* XXX - cover debugger pages */ 560200Sdg jae 1f 561200Sdg movl $0xa0,%ecx 562200Sdg1: 563757Sdg#endif /* BDE_DEBUGGER */ 5642512Sbde movl $PG_V|PG_KW,%eax /* kernel R/W, valid */ 565757Sdg lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 566757Sdg movl %ebx,_KPTphys-KERNBASE /* save in global */ 5674Srgrimes fillkpt 5684Srgrimes 569757Sdg#else /* !KGDB && !BDE_DEBUGGER */ 570757Sdg /* write protect kernel text (doesn't do a thing for 386's - only 486's) */ 571757Sdg movl $_etext-KERNBASE,%ecx /* get size of text */ 5723842Sdg addl $NBPG-1,%ecx /* round up to page */ 573757Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 574757Sdg movl $PG_V|PG_KR,%eax /* specify read only */ 5753842Sdg#if 0 5763842Sdg movl $_etext,%ecx /* get size of text */ 5773842Sdg subl $_btext,%ecx 5783842Sdg addl $NBPG-1,%ecx /* round up to page */ 5793842Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 5803842Sdg movl $_btext-KERNBASE,%eax /* get offset to physical memory */ 5813842Sdg orl $PG_V|PG_KR,%eax /* specify read only */ 5823842Sdg#endif 583757Sdg lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 584757Sdg movl %ebx,_KPTphys-KERNBASE /* save in global */ 585757Sdg fillkpt 586757Sdg 587757Sdg /* data and bss are r/w */ 588757Sdg andl $PG_FRAME,%eax /* strip to just addr of bss */ 589757Sdg movl _KERNend-KERNBASE,%ecx /* calculate size */ 590757Sdg subl %eax,%ecx 591757Sdg shrl $PGSHIFT,%ecx 592757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 593757Sdg fillkpt 5941321Sdg#endif /* KGDB || BDE_DEBUGGER */ 595757Sdg 596757Sdg/* now initialize the page dir, upages, p0stack PT, and page tables */ 597757Sdg 598974Sdg movl $(1+UPAGES+1+NKPT),%ecx /* number of PTEs */ 599757Sdg movl %esi,%eax /* phys address of PTD */ 600757Sdg andl $PG_FRAME,%eax /* convert to PFN, should be a NOP */ 6012512Sbde orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 602757Sdg movl %esi,%ebx /* calculate pte offset to ptd */ 603757Sdg shrl $PGSHIFT-2,%ebx 604757Sdg addl %esi,%ebx /* address of page directory */ 605757Sdg addl $((1+UPAGES+1)*NBPG),%ebx /* offset to kernel page tables */ 606757Sdg fillkpt 6071321Sdg 6084Srgrimes/* map I/O memory map */ 6094Srgrimes 610757Sdg movl _KPTphys-KERNBASE,%ebx /* base of kernel page tables */ 611757Sdg lea (0xa0 * PTESIZE)(%ebx),%ebx /* hardwire ISA hole at KERNBASE + 0xa0000 */ 612757Sdg movl $0x100-0xa0,%ecx /* for this many pte s, */ 6131046Sdg movl $(0xa0000|PG_V|PG_KW|PG_N),%eax /* valid, kernel read/write, non-cacheable */ 614757Sdg movl %ebx,_atdevphys-KERNBASE /* save phys addr of ptes */ 6154Srgrimes fillkpt 6164Srgrimes 6174Srgrimes /* map proc 0's kernel stack into user page table page */ 6184Srgrimes 619757Sdg movl $UPAGES,%ecx /* for this many pte s, */ 620757Sdg lea (1*NBPG)(%esi),%eax /* physical address in proc 0 */ 621757Sdg lea (KERNBASE)(%eax),%edx /* change into virtual addr */ 622757Sdg movl %edx,_proc0paddr-KERNBASE /* save VA for proc 0 init */ 623757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 624757Sdg lea ((1+UPAGES)*NBPG)(%esi),%ebx /* addr of stack page table in proc 0 */ 625757Sdg addl $(KSTKPTEOFF * PTESIZE),%ebx /* offset to kernel stack PTE */ 6264Srgrimes fillkpt 6274Srgrimes 6284Srgrimes/* 629757Sdg * Initialize kernel page table directory 6304Srgrimes */ 6314Srgrimes /* install a pde for temporary double map of bottom of VA */ 632757Sdg movl _KPTphys-KERNBASE,%eax 633757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 634757Sdg movl %eax,(%esi) /* which is where temp maps! */ 6354Srgrimes 636757Sdg /* initialize kernel pde's */ 637974Sdg movl $(NKPT),%ecx /* for this many PDEs */ 638757Sdg lea (KPTDI*PDESIZE)(%esi),%ebx /* offset of pde for kernel */ 6394Srgrimes fillkpt 6404Srgrimes 6414Srgrimes /* install a pde recursively mapping page directory as a page table! */ 642757Sdg movl %esi,%eax /* phys address of ptd in proc 0 */ 643757Sdg orl $PG_V|PG_KW,%eax /* pde entry is valid */ 644757Sdg movl %eax,PTDPTDI*PDESIZE(%esi) /* which is where PTmap maps! */ 6454Srgrimes 6464Srgrimes /* install a pde to map kernel stack for proc 0 */ 647757Sdg lea ((1+UPAGES)*NBPG)(%esi),%eax /* physical address of pt in proc 0 */ 648757Sdg orl $PG_V|PG_KW,%eax /* pde entry is valid */ 649757Sdg movl %eax,KSTKPTDI*PDESIZE(%esi) /* which is where kernel stack maps! */ 6504Srgrimes 651757Sdg#ifdef BDE_DEBUGGER 6524Srgrimes /* copy and convert stuff from old gdt and idt for debugger */ 6534Srgrimes 654757Sdg cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 6554Srgrimes jne 1f 656570Srgrimes movb $1,_bdb_exists-KERNBASE 6574Srgrimes1: 6584Srgrimes pushal 6594Srgrimes subl $2*6,%esp 6604Srgrimes 6614Srgrimes sgdt (%esp) 662757Sdg movl 2(%esp),%esi /* base address of current gdt */ 663570Srgrimes movl $_gdt-KERNBASE,%edi 6644Srgrimes movl %edi,2(%esp) 6654Srgrimes movl $8*18/4,%ecx 6661688Sdg cld 667757Sdg rep /* copy gdt */ 6684Srgrimes movsl 669570Srgrimes movl $_gdt-KERNBASE,-8+2(%edi) /* adjust gdt self-ptr */ 6704Srgrimes movb $0x92,-8+5(%edi) 6714Srgrimes 6724Srgrimes sidt 6(%esp) 673757Sdg movl 6+2(%esp),%esi /* base address of current idt */ 674757Sdg movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 6754Srgrimes movw 8(%esi),%ax 676570Srgrimes movl %eax,bdb_dbg_ljmp+1-KERNBASE /* ... immediate offset ... */ 6774Srgrimes movl 8+2(%esi),%eax 678570Srgrimes movw %ax,bdb_dbg_ljmp+5-KERNBASE /* ... and selector for ljmp */ 679757Sdg movl 24+4(%esi),%eax /* same for bpt descriptor */ 6804Srgrimes movw 24(%esi),%ax 681570Srgrimes movl %eax,bdb_bpt_ljmp+1-KERNBASE 6824Srgrimes movl 24+2(%esi),%eax 683570Srgrimes movw %ax,bdb_bpt_ljmp+5-KERNBASE 6844Srgrimes 685570Srgrimes movl $_idt-KERNBASE,%edi 6864Srgrimes movl %edi,6+2(%esp) 6874Srgrimes movl $8*4/4,%ecx 6881688Sdg cld 689757Sdg rep /* copy idt */ 6904Srgrimes movsl 6914Srgrimes 6924Srgrimes lgdt (%esp) 6934Srgrimes lidt 6(%esp) 6944Srgrimes 6954Srgrimes addl $2*6,%esp 6964Srgrimes popal 6971321Sdg#endif /* BDE_DEBUGGER */ 6984Srgrimes 699592Srgrimes /* load base of page directory and enable mapping */ 700757Sdg movl %esi,%eax /* phys address of ptd in proc 0 */ 701757Sdg movl %eax,%cr3 /* load ptd addr into mmu */ 702757Sdg movl %cr0,%eax /* get control word */ 703757Sdg orl $CR0_PE|CR0_PG,%eax /* enable paging */ 704757Sdg movl %eax,%cr0 /* and let's page NOW! */ 7054Srgrimes 706757Sdg pushl $begin /* jump to high mem */ 7074Srgrimes ret 7084Srgrimes 709570Srgrimesbegin: /* now running relocated at KERNBASE where the system is linked to run */ 710757Sdg movl _atdevphys,%edx /* get pte PA */ 711757Sdg subl _KPTphys,%edx /* remove base of ptes, now have phys offset */ 712757Sdg shll $PGSHIFT-2,%edx /* corresponding to virt offset */ 713757Sdg addl $KERNBASE,%edx /* add virtual base */ 714570Srgrimes movl %edx,_atdevbase 7153728Sphk 7163861Sbde#include "sc.h" 7173861Sbde#if NSC > 0 7183728Sphk /* XXX: can't scinit relocate Crtat relative to atdevbase itself? */ 7193728Sphk .globl _Crtat /* XXX - locore should not know about */ 7203728Sphk movl _Crtat,%eax /* variables of device drivers (pccons)! */ 7213728Sphk subl $(KERNBASE+0xA0000),%eax 7224Srgrimes addl %eax,%edx 7234Srgrimes movl %edx,_Crtat 7243728Sphk#endif 7254Srgrimes 726757Sdg /* set up bootstrap stack - 48 bytes */ 727570Srgrimes movl $_kstack+UPAGES*NBPG-4*12,%esp /* bootstrap stack end location */ 728757Sdg xorl %eax,%eax /* mark end of frames */ 7294Srgrimes movl %eax,%ebp 730570Srgrimes movl _proc0paddr,%eax 731570Srgrimes movl %esi,PCB_CR3(%eax) 7324Srgrimes 733757Sdg#ifdef BDE_DEBUGGER 7344Srgrimes /* relocate debugger gdt entries */ 7354Srgrimes 736757Sdg movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 7374Srgrimes movl $9,%ecx 7384Srgrimesreloc_gdt: 7391321Sdg movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 740757Sdg addl $8,%eax /* now KERNBASE>>24 */ 7414Srgrimes loop reloc_gdt 7424Srgrimes 7434Srgrimes cmpl $0,_bdb_exists 7444Srgrimes je 1f 7454Srgrimes int $3 7464Srgrimes1: 7471321Sdg#endif /* BDE_DEBUGGER */ 7484Srgrimes 749608Srgrimes /* 750608Srgrimes * Skip over the page tables and the kernel stack 751608Srgrimes */ 752974Sdg lea ((1+UPAGES+1+NKPT)*NBPG)(%esi),%esi 753608Srgrimes 754757Sdg pushl %esi /* value of first for init386(first) */ 755757Sdg call _init386 /* wire 386 chip for unix operation */ 7561549Srgrimes popl %esi 757200Sdg 7581549Srgrimes .globl __ucodesel,__udatasel 7591549Srgrimes 7601549Srgrimes pushl $0 /* unused */ 7611549Srgrimes pushl __udatasel /* ss */ 7621549Srgrimes pushl $0 /* esp - filled in by execve() */ 7632500Sdg pushl $PSL_USERSET /* eflags (ring 0, int enab) */ 7641549Srgrimes pushl __ucodesel /* cs */ 7651549Srgrimes pushl $0 /* eip - filled in by execve() */ 7661549Srgrimes subl $(12*4),%esp /* space for rest of registers */ 7671549Srgrimes 7681549Srgrimes pushl %esp /* call main with frame pointer */ 769757Sdg call _main /* autoconfiguration, mountroot etc */ 7704Srgrimes 7711549Srgrimes addl $(13*4),%esp /* back to a frame we can return with */ 7721549Srgrimes 773134Sdg /* 774570Srgrimes * now we've run main() and determined what cpu-type we are, we can 775570Srgrimes * enable WP mode on i486 cpus and above. 7761058Sdg */ 7771058Sdg#if defined(I486_CPU) || defined(I586_CPU) 7781058Sdg cmpl $CPUCLASS_386,_cpu_class 7791058Sdg je 1f 7801058Sdg movl %cr0,%eax /* get control word */ 7811058Sdg orl $CR0_WP,%eax /* enable write protect for all modes */ 7821058Sdg movl %eax,%cr0 /* and do it */ 7831058Sdg#endif 7841058Sdg /* 785134Sdg * on return from main(), we are process 1 786134Sdg * set up address space and stack so that we can 'return' to user mode 787134Sdg */ 7881058Sdg1: 7894Srgrimes movl __ucodesel,%eax 7904Srgrimes movl __udatasel,%ecx 7911549Srgrimes 7924Srgrimes movl %cx,%ds 7934Srgrimes movl %cx,%es 794757Sdg movl %ax,%fs /* double map cs to fs */ 795757Sdg movl %cx,%gs /* and ds to gs */ 7961549Srgrimes iret /* goto user! */ 7974Srgrimes 7981549Srgrimes#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 7994Srgrimes 800200SdgNON_GPROF_ENTRY(sigcode) 801592Srgrimes call SIGF_HANDLER(%esp) 802757Sdg lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 803757Sdg /* copy at 8(%esp)) */ 8044Srgrimes pushl %eax 805757Sdg pushl %eax /* junk to fake return address */ 806757Sdg movl $103,%eax /* XXX sigreturn() */ 807757Sdg LCALL(0x7,0) /* enter kernel with args on stack */ 808757Sdg hlt /* never gets here */ 8094Srgrimes 8104Srgrimes .globl _szsigcode 8114Srgrimes_szsigcode: 8124Srgrimes .long _szsigcode-_sigcode 813