locore.s revision 3842
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 373842Sdg * $Id: locore.s,v 1.38 1994/10/22 17:51:46 phk 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 */ 573489Sphk#include "apm.h" 583489Sphk#if NAPM > 0 593258Sdg#define ASM 603258Sdg#include <machine/apm_bios.h> 613258Sdg#include <machine/apm_segments.h> 623489Sphk#endif /* NAPM */ 634Srgrimes 644Srgrimes/* 65757Sdg * XXX 66757Sdg * 674Srgrimes * Note: This version greatly munged to avoid various assembler errors 684Srgrimes * that may be fixed in newer versions of gas. Perhaps newer versions 694Srgrimes * will have more pleasant appearance. 704Srgrimes */ 714Srgrimes 72200Sdg/* 734Srgrimes * PTmap is recursive pagemap at top of virtual address space. 744Srgrimes * Within PTmap, the page directory can be found (third indirection). 754Srgrimes */ 76592Srgrimes .globl _PTmap,_PTD,_PTDpde,_Sysmap 77592Srgrimes .set _PTmap,PTDPTDI << PDRSHIFT 78592Srgrimes .set _PTD,_PTmap + (PTDPTDI * NBPG) 79757Sdg .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 80592Srgrimes 81757Sdg/* Sysmap is the base address of the kernel page tables */ 82608Srgrimes .set _Sysmap,_PTmap + (KPTDI * NBPG) 834Srgrimes 844Srgrimes/* 854Srgrimes * APTmap, APTD is the alternate recursive pagemap. 864Srgrimes * It's used when modifying another process's page tables. 874Srgrimes */ 88592Srgrimes .globl _APTmap,_APTD,_APTDpde 89592Srgrimes .set _APTmap,APTDPTDI << PDRSHIFT 90592Srgrimes .set _APTD,_APTmap + (APTDPTDI * NBPG) 91757Sdg .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 924Srgrimes 934Srgrimes/* 944Srgrimes * Access to each processes kernel stack is via a region of 954Srgrimes * per-process address space (at the beginning), immediatly above 964Srgrimes * the user process stack. 974Srgrimes */ 98570Srgrimes .set _kstack,USRSTACK 99134Sdg .globl _kstack 1004Srgrimes 101556Srgrimes/* 102556Srgrimes * Globals 103556Srgrimes */ 104556Srgrimes .data 105134Sdg 1063842Sdg .globl tmpstk 1073842Sdg .space 0x1000 /* space for tmpstk - temporary stack */ 1083842Sdgtmpstk: 1093842Sdg .long 0 /* for debugging tmpstk stack underflow */ 1103842Sdg 111592Srgrimes .globl _boothowto,_bootdev,_curpcb 112134Sdg 1131998Swollman .globl _cpu,_cold,_atdevbase,_cpu_vendor,_cpu_id 1142783Ssos 1152783Ssos .globl _video_mode_ptr 1162783Ssos 117757Sdg_cpu: .long 0 /* are we 386, 386sx, or 486 */ 1182216Sbde_cpu_id: .long 0 /* stepping ID */ 1192216Sbde_cpu_vendor: .space 20 /* CPU origin code */ 1202783Ssos_video_mode_ptr: .long 0 121757Sdg_cold: .long 1 /* cold till we are not */ 122757Sdg_atdevbase: .long 0 /* location of start of iomem in virtual */ 123757Sdg_atdevphys: .long 0 /* location of device mapping ptes (phys) */ 1244Srgrimes 125757Sdg .globl _KERNend 126757Sdg_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 127757Sdg 128592Srgrimes .globl _IdlePTD,_KPTphys 129757Sdg_IdlePTD: .long 0 /* phys addr of kernel PTD */ 130757Sdg_KPTphys: .long 0 /* phys addr of kernel page tables */ 1314Srgrimes 132757Sdg .globl _proc0paddr 133757Sdg_proc0paddr: .long 0 /* address of proc 0 address space */ 134134Sdg 135757Sdg#ifdef BDE_DEBUGGER 136757Sdg .globl _bdb_exists /* flag to indicate BDE debugger is available */ 1371321Sdg_bdb_exists: .long 0 138757Sdg#endif 1393489Sphk#if NAPM > 0 1403258Sdg .globl _apm_current_gdt_pdesc /* current GDT pseudo desc. */ 1413258Sdg_apm_current_gdt_pdesc: 1423314Sdg .word 0, 0, 0 143718Swollman 1443258Sdg .globl _bootstrap_gdt 1453258Sdg_bootstrap_gdt: 1463258Sdg .space SIZEOF_GDT * BOOTSTRAP_GDT_NUM 1473489Sphk#endif /* NAPM */ 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: 1673384Srgrimes /* Set up a real frame, some day we will be doing returns */ 1683384Srgrimes pushl %ebp 1693384Srgrimes movl %esp, %ebp 1703384Srgrimes 1712512Sbde /* Don't trust what the BIOS gives for eflags. */ 1722512Sbde pushl $PSL_MBO 1732486Sdg popfl 1742486Sdg 1754Srgrimes /* 1763284Srgrimes * This code is called in different ways depending on what loaded 1773284Srgrimes * and started the kernel. This is used to detect how we get the 1783284Srgrimes * arguments from the other code and what we do with them. 1793284Srgrimes * 1803284Srgrimes * Old disk boot blocks: 1813284Srgrimes * (*btext)(howto, bootdev, cyloffset, esym); 1823284Srgrimes * [return address == 0, and can NOT be returned to] 1833284Srgrimes * [cyloffset was not supported by the FreeBSD boot code 1843284Srgrimes * and always passed in as 0] 1853284Srgrimes * [esym is also known as total in the boot code, and 1863284Srgrimes * was never properly supported by the FreeBSD boot code] 1873284Srgrimes * 1883284Srgrimes * Old diskless netboot code: 1893284Srgrimes * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 1903284Srgrimes * [return address != 0, and can NOT be returned to] 1913284Srgrimes * If we are being booted by this code it will NOT work, 1923284Srgrimes * so we are just going to halt if we find this case. 1933284Srgrimes * 1943284Srgrimes * New uniform boot code: 1953284Srgrimes * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 1963284Srgrimes * [return address != 0, and can be returned to] 1973284Srgrimes * 1983284Srgrimes * There may seem to be a lot of wasted arguments in here, but 1993384Srgrimes * that is so the newer boot code can still load very old kernels 2003384Srgrimes * and old boot code can load new kernels. 2014Srgrimes */ 2023284Srgrimes 2033284Srgrimes /* 2043284Srgrimes * The old style disk boot blocks fake a frame on the stack and 2053284Srgrimes * did an lret to get here. The frame on the stack has a return 2063284Srgrimes * address of 0. 2073284Srgrimes */ 2083384Srgrimes cmpl $0,4(%ebp) 2093284Srgrimes je 2f /* olddiskboot: */ 2103284Srgrimes 2113284Srgrimes /* 2123284Srgrimes * We have some form of return address, so this is either the 2133284Srgrimes * old diskless netboot code, or the new uniform code. That can 2143284Srgrimes * be detected by looking at the 5th argument, it if is 0 we 2153284Srgrimes * we are being booted by the new unifrom boot code. 2163284Srgrimes */ 2173384Srgrimes cmpl $0,24(%ebp) 2183284Srgrimes je 1f /* newboot: */ 2193284Srgrimes 2203284Srgrimes /* 2213284Srgrimes * Seems we have been loaded by the old diskless boot code, we 2223284Srgrimes * don't stand a chance of running as the diskless structure 2233284Srgrimes * changed considerably between the two, so just halt. 2243284Srgrimes */ 2253284Srgrimes hlt 2263284Srgrimes 2273284Srgrimes /* 2283384Srgrimes * We have been loaded by the new uniform boot code. 2293384Srgrimes * Lets check the bootinfo version, and if we do not understand 2303384Srgrimes * it we return to the loader with a status of 1 to indicate this error 2313284Srgrimes */ 2323284Srgrimes1: /* newboot: */ 2333384Srgrimes movl 28(%ebp),%ebx /* &bootinfo.version */ 2343384Srgrimes movl BOOTINFO_VERSION(%ebx),%eax 2353384Srgrimes cmpl $1,%eax /* We only understand version 1 */ 2363384Srgrimes je 1f 2373384Srgrimes movl $1,%eax /* Return status */ 2383384Srgrimes leave 2393384Srgrimes ret 2403284Srgrimes 2413384Srgrimes1: 2423284Srgrimes /* 2433384Srgrimes * If we have a kernelname copy it in 2443384Srgrimes */ 2453384Srgrimes movl BOOTINFO_KERNELNAME(%ebx),%esi 2463384Srgrimes cmpl $0,%esi 2473384Srgrimes je 1f /* No kernelname */ 2483384Srgrimes lea _kernelname-KERNBASE,%edi 2493384Srgrimes movl $MAXPATHLEN,%ecx /* Brute force!!! */ 2503384Srgrimes cld 2513384Srgrimes rep 2523384Srgrimes movsb 2533384Srgrimes 2543384Srgrimes1: 2553426Srgrimes#ifdef NFS 2563384Srgrimes /* 2573384Srgrimes * If we have a nfs_diskless structure copy it in 2583384Srgrimes */ 2593384Srgrimes movl BOOTINFO_NFS_DISKLESS(%ebx),%esi 2603384Srgrimes cmpl $0,%esi 2613384Srgrimes je 2f 2623384Srgrimes lea _nfs_diskless-KERNBASE,%edi 2633384Srgrimes movl $NFSDISKLESS_SIZE,%ecx 2643384Srgrimes cld 2653384Srgrimes rep 2663384Srgrimes movsb 2673795Sphk lea _nfs_diskless_valid-KERNBASE,%edi 2683795Sphk movl $1,(%edi) 2693406Sdg#endif 2703384Srgrimes 2713384Srgrimes /* 2723284Srgrimes * The old style disk boot. 2733284Srgrimes * (*btext)(howto, bootdev, cyloffset, esym); 2743384Srgrimes * Note that the newer boot code just falls into here to pick 2753384Srgrimes * up howto and bootdev, cyloffset and esym are no longer used 2763284Srgrimes */ 2773284Srgrimes2: /* olddiskboot: */ 2783384Srgrimes movl 8(%ebp),%eax 279570Srgrimes movl %eax,_boothowto-KERNBASE 2803384Srgrimes movl 12(%ebp),%eax 281570Srgrimes movl %eax,_bootdev-KERNBASE 2822783Ssos 2832783Ssos /* get the BIOS video mode pointer */ 2842783Ssos movl $0x4a8, %ecx 2852783Ssos movl (%ecx), %eax 2862783Ssos movl %eax, %ecx 2872783Ssos shrl $12, %ecx 2882783Ssos andl $0xffff0000, %ecx 2892783Ssos andl $0x0000ffff, %eax 2902783Ssos orl %ecx, %eax 2912783Ssos movl (%eax), %eax 2922783Ssos movl %eax, %ecx 2932783Ssos shrl $12, %ecx 2942783Ssos andl $0xffff0000, %ecx 2952783Ssos andl $0x0000ffff, %eax 2962783Ssos orl %ecx, %eax 2972783Ssos addl $KERNBASE, %eax 2982783Ssos movl %eax, _video_mode_ptr-KERNBASE 2992783Ssos 3003489Sphk#if NAPM > 0 3013258Sdg /* 3023258Sdg * Setup APM BIOS: 3033258Sdg * 3043258Sdg * APM BIOS initialization should be done from real mode or V86 mode. 3053258Sdg * 3063258Sdg * (by HOSOKAWA, Tatsumi <hosokawa@mt.cs.keio.ac.jp>) 3073258Sdg */ 3084Srgrimes 3093258Sdg /* 3103258Sdg * Copy APM initializer under 1MB boundary: 3113258Sdg * 3123258Sdg * APM initializer program must switch the CPU to real mode. 3133258Sdg * But FreeBSD kernel runs above 1MB boundary. So we must 3143258Sdg * copy the initializer code to conventional memory. 3153258Sdg */ 3163258Sdg movl _apm_init_image_size-KERNBASE, %ecx /* size */ 3173258Sdg lea _apm_init_image-KERNBASE, %esi /* source */ 3183258Sdg movl $ APM_OURADDR, %edi /* destination */ 3193258Sdg cld 3203258Sdg rep 3213258Sdg movsb 3223258Sdg 3233258Sdg /* get GDT base */ 3243258Sdg sgdt _apm_current_gdt_pdesc-KERNBASE 3253258Sdg 3263258Sdg /* copy GDT to _bootstrap_gdt */ 3273258Sdg xorl %ecx, %ecx 3283258Sdg movw _apm_current_gdt_pdesc-KERNBASE, %cx 3293258Sdg movl _apm_current_gdt_pdesc-KERNBASE+2, %esi 3303258Sdg lea _bootstrap_gdt-KERNBASE, %edi 3313258Sdg cld 3323258Sdg rep 3333258Sdg movsb 3343258Sdg 3353258Sdg /* setup GDT pseudo descriptor */ 3363258Sdg movw $(SIZEOF_GDT*BOOTSTRAP_GDT_NUM), %ax 3373258Sdg movw %ax, _apm_current_gdt_pdesc-KERNBASE 3383258Sdg leal _bootstrap_gdt-KERNBASE, %eax 3393258Sdg movl %eax, _apm_current_gdt_pdesc-KERNBASE+2 3403258Sdg 3413258Sdg /* load new GDTR */ 3423258Sdg lgdt _apm_current_gdt_pdesc-KERNBASE 3433258Sdg 3443258Sdg /* setup GDT for APM initializer */ 3453258Sdg lea _bootstrap_gdt-KERNBASE, %ecx 3463258Sdg movl $(APM_OURADDR), %eax /* use %ax for 15..0 */ 3473258Sdg movl %eax, %ebx 3483258Sdg shrl $16, %ebx /* use %bl for 23..16 */ 3493258Sdg /* use %bh for 31..24 */ 3503258Sdg#define APM_SETUP_GDT(index, attrib) \ 3513258Sdg movl $(index), %si ; \ 3523258Sdg lea 0(%ecx,%esi,8), %edx ; \ 3533258Sdg movw $0xffff, (%edx) ; \ 3543258Sdg movw %ax, 2(%edx) ; \ 3553258Sdg movb %bl, 4(%edx) ; \ 3563258Sdg movw $(attrib), 5(%edx) ; \ 3573258Sdg movb %bh, 7(%edx) 3583258Sdg 3593258Sdg APM_SETUP_GDT(APM_INIT_CS_INDEX , CS32_ATTRIB) 3603258Sdg APM_SETUP_GDT(APM_INIT_DS_INDEX , DS32_ATTRIB) 3613258Sdg APM_SETUP_GDT(APM_INIT_CS16_INDEX, CS16_ATTRIB) 3623258Sdg 3633258Sdg /* 3643258Sdg * Call the initializer: 3653258Sdg * 3663258Sdg * direct intersegment call to conventional memory code 3673258Sdg */ 3683258Sdg .byte 0x9a /* actually, lcall $APM_INIT_CS_SEL, $0 */ 3693258Sdg .long 0 3703258Sdg .word APM_INIT_CS_SEL 3713258Sdg 3723258Sdg movw %ax, _apm_version-KERNBASE 3733258Sdg movl %ebx, _apm_cs_entry-KERNBASE 3743258Sdg movw %cx, _apm_cs32_base-KERNBASE 3753258Sdg shrl $16, %ecx 3763258Sdg movw %cx, _apm_cs16_base-KERNBASE 3773258Sdg movw %dx, _apm_ds_base-KERNBASE 3783258Sdg movw %si, _apm_cs_limit-KERNBASE 3793258Sdg shrl $16, %esi 3803258Sdg movw %si, _apm_ds_limit-KERNBASE 3813258Sdg movw %di, _apm_flags-KERNBASE 3823489Sphk#endif /* NAPM */ 3833258Sdg 3841998Swollman /* Find out our CPU type. */ 3851321Sdg 3861998Swollman /* Try to toggle alignment check flag; does not exist on 386. */ 3871998Swollman pushfl 3881998Swollman popl %eax 3891998Swollman movl %eax,%ecx 3901998Swollman orl $PSL_AC,%eax 3911998Swollman pushl %eax 3921998Swollman popfl 3931998Swollman pushfl 3941998Swollman popl %eax 3951998Swollman xorl %ecx,%eax 3961998Swollman andl $PSL_AC,%eax 3971998Swollman pushl %ecx 3981998Swollman popfl 3991998Swollman 4001998Swollman testl %eax,%eax 4011998Swollman jnz 1f 4021998Swollman movl $CPU_386,_cpu-KERNBASE 403556Srgrimes jmp 2f 4041998Swollman 4051998Swollman1: /* Try to toggle identification flag; does not exist on early 486s. */ 4061998Swollman pushfl 4071998Swollman popl %eax 4081998Swollman movl %eax,%ecx 4091998Swollman xorl $PSL_ID,%eax 4101998Swollman pushl %eax 4111998Swollman popfl 4121998Swollman pushfl 4131998Swollman popl %eax 4141998Swollman xorl %ecx,%eax 4151998Swollman andl $PSL_ID,%eax 4161998Swollman pushl %ecx 4171998Swollman popfl 4181998Swollman 4191998Swollman testl %eax,%eax 4201998Swollman jnz 1f 4211998Swollman movl $CPU_486,_cpu-KERNBASE 4222495Spst 4232495Spst /* check for Cyrix 486DLC -- based on check routine */ 4242495Spst /* documented in "Cx486SLC/e SMM Programmer's Guide" */ 4252495Spst xorw %dx,%dx 4262495Spst cmpw %dx,%dx # set flags to known state 4272495Spst pushfw 4282495Spst popw %cx # store flags in ecx 4292495Spst movw $0xffff,%ax 4302495Spst movw $0x0004,%bx 4312495Spst divw %bx 4322495Spst pushfw 4332495Spst popw %ax 4342495Spst andw $0x08d5,%ax # mask off important bits 4352495Spst andw $0x08d5,%cx 4362495Spst cmpw %ax,%cx 4372495Spst 4382495Spst jnz 2f # if flags changed, Intel chip 4392495Spst 4402495Spst movl $CPU_486DLC,_cpu-KERNBASE # set CPU value for Cyrix 4412495Spst movl $0x69727943,_cpu_vendor-KERNBASE # store vendor string 4422495Spst movw $0x0078,_cpu_vendor-KERNBASE+4 4432495Spst 4442495Spst invd # Start with guaranteed clean cache 4452495Spst /* Disable caching of the ISA hole only. */ 4462495Spst movb $CCR0,%al # Configuration Register index (CCR0) 4472495Spst outb %al,$0x22 4482495Spst inb $0x23,%al 4493117Spst orb $(CCR0_NC1|CCR0_BARB),%al 4502495Spst outb %al,$0x23 4512495Spst invd 4521998Swollman jmp 2f 4531998Swollman 4541998Swollman1: /* Use the `cpuid' instruction. */ 4551998Swollman xorl %eax,%eax 4561998Swollman .byte 0x0f,0xa2 # cpuid 0 4571998Swollman movl %ebx,_cpu_vendor-KERNBASE # store vendor string 4581998Swollman movl %edx,_cpu_vendor+4-KERNBASE 4591998Swollman movl %ecx,_cpu_vendor+8-KERNBASE 4601998Swollman movb $0,_cpu_vendor+12-KERNBASE 4611998Swollman 4621998Swollman movl $1,%eax 4631998Swollman .byte 0x0f,0xa2 # cpuid 1 4641998Swollman movl %eax,_cpu_id-KERNBASE # store cpu_id 4651998Swollman rorl $8,%eax # extract family type 4661998Swollman andl $15,%eax 4671998Swollman cmpl $5,%eax 4681998Swollman jae 1f 4691998Swollman 4701998Swollman /* less than Pentium; must be 486 */ 4711998Swollman movl $CPU_486,_cpu-KERNBASE 4721998Swollman jmp 2f 4731998Swollman 4741998Swollman1: movl $CPU_586,_cpu-KERNBASE 475556Srgrimes2: 476556Srgrimes 4774Srgrimes /* 4784Srgrimes * Finished with old stack; load new %esp now instead of later so 4794Srgrimes * we can trace this code without having to worry about the trace 4804Srgrimes * trap clobbering the memory test or the zeroing of the bss+bootstrap 4814Srgrimes * page tables. 4824Srgrimes * 4834Srgrimes * XXX - wdboot clears the bss after testing that this is safe. 4844Srgrimes * This is too wasteful - memory below 640K is scarce. The boot 4854Srgrimes * program should check: 4864Srgrimes * text+data <= &stack_variable - more_space_for_stack 4874Srgrimes * text+data+bss+pad+space_for_page_tables <= end_of_memory 4884Srgrimes * Oops, the gdt is in the carcass of the boot program so clearing 4894Srgrimes * the rest of memory is still not possible. 4904Srgrimes */ 491757Sdg movl $tmpstk-KERNBASE,%esp /* bootstrap stack end location */ 4924Srgrimes 493570Srgrimes/* 494570Srgrimes * Virtual address space of kernel: 495570Srgrimes * 496570Srgrimes * text | data | bss | [syms] | page dir | proc0 kernel stack | usr stk map | Sysmap 497974Sdg * pages: 1 UPAGES (2) 1 NKPT (7) 498570Srgrimes */ 499570Srgrimes 5004Srgrimes/* find end of kernel image */ 501570Srgrimes movl $_end-KERNBASE,%ecx 502757Sdg addl $NBPG-1,%ecx /* page align up */ 5034Srgrimes andl $~(NBPG-1),%ecx 5041321Sdg movl %ecx,%esi /* esi = start of free memory */ 505757Sdg movl %ecx,_KERNend-KERNBASE /* save end of kernel */ 5064Srgrimes 507757Sdg/* clear bss */ 508570Srgrimes movl $_edata-KERNBASE,%edi 509760Srgrimes subl %edi,%ecx /* get amount to clear */ 510757Sdg xorl %eax,%eax /* specify zero fill */ 5114Srgrimes cld 5124Srgrimes rep 5134Srgrimes stosb 5144Srgrimes 515608Srgrimes/* 516974Sdg * The value in esi is both the end of the kernel bss and a pointer to 517974Sdg * the kernel page directory, and is used by the rest of locore to build 518974Sdg * the tables. 519974Sdg * esi + 1(page dir) + 2(UPAGES) + 1(p0stack) + NKPT(number of kernel 520757Sdg * page table pages) is then passed on the stack to init386(first) as 521757Sdg * the value first. esi should ALWAYS be page aligned!! 522608Srgrimes */ 523757Sdg movl %esi,%ecx /* Get current first availiable address */ 524608Srgrimes 525757Sdg/* clear pagetables, page directory, stack, etc... */ 526757Sdg movl %esi,%edi /* base (page directory) */ 527974Sdg movl $((1+UPAGES+1+NKPT)*NBPG),%ecx /* amount to clear */ 528757Sdg xorl %eax,%eax /* specify zero fill */ 529757Sdg cld 530757Sdg rep 531757Sdg stosb 532757Sdg 533757Sdg/* physical address of Idle proc/kernel page directory */ 534570Srgrimes movl %esi,_IdlePTD-KERNBASE 5354Srgrimes 536592Srgrimes/* 537592Srgrimes * fillkpt 538592Srgrimes * eax = (page frame address | control | status) == pte 539592Srgrimes * ebx = address of page table 540592Srgrimes * ecx = how many pages to map 541592Srgrimes */ 5424Srgrimes#define fillkpt \ 5434Srgrimes1: movl %eax,(%ebx) ; \ 544570Srgrimes addl $NBPG,%eax ; /* increment physical address */ \ 5454Srgrimes addl $4,%ebx ; /* next pte */ \ 5464Srgrimes loop 1b ; 5474Srgrimes 5484Srgrimes/* 5494Srgrimes * Map Kernel 5504Srgrimes * 5514Srgrimes * First step - build page tables 5524Srgrimes */ 553757Sdg#if defined (KGDB) || defined (BDE_DEBUGGER) 554757Sdg movl _KERNend-KERNBASE,%ecx /* this much memory, */ 555757Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 556757Sdg#ifdef BDE_DEBUGGER 557757Sdg cmpl $0xa0,%ecx /* XXX - cover debugger pages */ 558200Sdg jae 1f 559200Sdg movl $0xa0,%ecx 560200Sdg1: 561757Sdg#endif /* BDE_DEBUGGER */ 5622512Sbde movl $PG_V|PG_KW,%eax /* kernel R/W, valid */ 563757Sdg lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 564757Sdg movl %ebx,_KPTphys-KERNBASE /* save in global */ 5654Srgrimes fillkpt 5664Srgrimes 567757Sdg#else /* !KGDB && !BDE_DEBUGGER */ 568757Sdg /* write protect kernel text (doesn't do a thing for 386's - only 486's) */ 569757Sdg movl $_etext-KERNBASE,%ecx /* get size of text */ 5703842Sdg addl $NBPG-1,%ecx /* round up to page */ 571757Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 572757Sdg movl $PG_V|PG_KR,%eax /* specify read only */ 5733842Sdg#if 0 5743842Sdg movl $_etext,%ecx /* get size of text */ 5753842Sdg subl $_btext,%ecx 5763842Sdg addl $NBPG-1,%ecx /* round up to page */ 5773842Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 5783842Sdg movl $_btext-KERNBASE,%eax /* get offset to physical memory */ 5793842Sdg orl $PG_V|PG_KR,%eax /* specify read only */ 5803842Sdg#endif 581757Sdg lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 582757Sdg movl %ebx,_KPTphys-KERNBASE /* save in global */ 583757Sdg fillkpt 584757Sdg 585757Sdg /* data and bss are r/w */ 586757Sdg andl $PG_FRAME,%eax /* strip to just addr of bss */ 587757Sdg movl _KERNend-KERNBASE,%ecx /* calculate size */ 588757Sdg subl %eax,%ecx 589757Sdg shrl $PGSHIFT,%ecx 590757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 591757Sdg fillkpt 5921321Sdg#endif /* KGDB || BDE_DEBUGGER */ 593757Sdg 594757Sdg/* now initialize the page dir, upages, p0stack PT, and page tables */ 595757Sdg 596974Sdg movl $(1+UPAGES+1+NKPT),%ecx /* number of PTEs */ 597757Sdg movl %esi,%eax /* phys address of PTD */ 598757Sdg andl $PG_FRAME,%eax /* convert to PFN, should be a NOP */ 5992512Sbde orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 600757Sdg movl %esi,%ebx /* calculate pte offset to ptd */ 601757Sdg shrl $PGSHIFT-2,%ebx 602757Sdg addl %esi,%ebx /* address of page directory */ 603757Sdg addl $((1+UPAGES+1)*NBPG),%ebx /* offset to kernel page tables */ 604757Sdg fillkpt 6051321Sdg 6064Srgrimes/* map I/O memory map */ 6074Srgrimes 608757Sdg movl _KPTphys-KERNBASE,%ebx /* base of kernel page tables */ 609757Sdg lea (0xa0 * PTESIZE)(%ebx),%ebx /* hardwire ISA hole at KERNBASE + 0xa0000 */ 610757Sdg movl $0x100-0xa0,%ecx /* for this many pte s, */ 6111046Sdg movl $(0xa0000|PG_V|PG_KW|PG_N),%eax /* valid, kernel read/write, non-cacheable */ 612757Sdg movl %ebx,_atdevphys-KERNBASE /* save phys addr of ptes */ 6134Srgrimes fillkpt 6144Srgrimes 6154Srgrimes /* map proc 0's kernel stack into user page table page */ 6164Srgrimes 617757Sdg movl $UPAGES,%ecx /* for this many pte s, */ 618757Sdg lea (1*NBPG)(%esi),%eax /* physical address in proc 0 */ 619757Sdg lea (KERNBASE)(%eax),%edx /* change into virtual addr */ 620757Sdg movl %edx,_proc0paddr-KERNBASE /* save VA for proc 0 init */ 621757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 622757Sdg lea ((1+UPAGES)*NBPG)(%esi),%ebx /* addr of stack page table in proc 0 */ 623757Sdg addl $(KSTKPTEOFF * PTESIZE),%ebx /* offset to kernel stack PTE */ 6244Srgrimes fillkpt 6254Srgrimes 6264Srgrimes/* 627757Sdg * Initialize kernel page table directory 6284Srgrimes */ 6294Srgrimes /* install a pde for temporary double map of bottom of VA */ 630757Sdg movl _KPTphys-KERNBASE,%eax 631757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 632757Sdg movl %eax,(%esi) /* which is where temp maps! */ 6334Srgrimes 634757Sdg /* initialize kernel pde's */ 635974Sdg movl $(NKPT),%ecx /* for this many PDEs */ 636757Sdg lea (KPTDI*PDESIZE)(%esi),%ebx /* offset of pde for kernel */ 6374Srgrimes fillkpt 6384Srgrimes 6394Srgrimes /* install a pde recursively mapping page directory as a page table! */ 640757Sdg movl %esi,%eax /* phys address of ptd in proc 0 */ 641757Sdg orl $PG_V|PG_KW,%eax /* pde entry is valid */ 642757Sdg movl %eax,PTDPTDI*PDESIZE(%esi) /* which is where PTmap maps! */ 6434Srgrimes 6444Srgrimes /* install a pde to map kernel stack for proc 0 */ 645757Sdg lea ((1+UPAGES)*NBPG)(%esi),%eax /* physical address of pt in proc 0 */ 646757Sdg orl $PG_V|PG_KW,%eax /* pde entry is valid */ 647757Sdg movl %eax,KSTKPTDI*PDESIZE(%esi) /* which is where kernel stack maps! */ 6484Srgrimes 649757Sdg#ifdef BDE_DEBUGGER 6504Srgrimes /* copy and convert stuff from old gdt and idt for debugger */ 6514Srgrimes 652757Sdg cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 6534Srgrimes jne 1f 654570Srgrimes movb $1,_bdb_exists-KERNBASE 6554Srgrimes1: 6564Srgrimes pushal 6574Srgrimes subl $2*6,%esp 6584Srgrimes 6594Srgrimes sgdt (%esp) 660757Sdg movl 2(%esp),%esi /* base address of current gdt */ 661570Srgrimes movl $_gdt-KERNBASE,%edi 6624Srgrimes movl %edi,2(%esp) 6634Srgrimes movl $8*18/4,%ecx 6641688Sdg cld 665757Sdg rep /* copy gdt */ 6664Srgrimes movsl 667570Srgrimes movl $_gdt-KERNBASE,-8+2(%edi) /* adjust gdt self-ptr */ 6684Srgrimes movb $0x92,-8+5(%edi) 6694Srgrimes 6704Srgrimes sidt 6(%esp) 671757Sdg movl 6+2(%esp),%esi /* base address of current idt */ 672757Sdg movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 6734Srgrimes movw 8(%esi),%ax 674570Srgrimes movl %eax,bdb_dbg_ljmp+1-KERNBASE /* ... immediate offset ... */ 6754Srgrimes movl 8+2(%esi),%eax 676570Srgrimes movw %ax,bdb_dbg_ljmp+5-KERNBASE /* ... and selector for ljmp */ 677757Sdg movl 24+4(%esi),%eax /* same for bpt descriptor */ 6784Srgrimes movw 24(%esi),%ax 679570Srgrimes movl %eax,bdb_bpt_ljmp+1-KERNBASE 6804Srgrimes movl 24+2(%esi),%eax 681570Srgrimes movw %ax,bdb_bpt_ljmp+5-KERNBASE 6824Srgrimes 683570Srgrimes movl $_idt-KERNBASE,%edi 6844Srgrimes movl %edi,6+2(%esp) 6854Srgrimes movl $8*4/4,%ecx 6861688Sdg cld 687757Sdg rep /* copy idt */ 6884Srgrimes movsl 6894Srgrimes 6904Srgrimes lgdt (%esp) 6914Srgrimes lidt 6(%esp) 6924Srgrimes 6934Srgrimes addl $2*6,%esp 6944Srgrimes popal 6951321Sdg#endif /* BDE_DEBUGGER */ 6964Srgrimes 697592Srgrimes /* load base of page directory and enable mapping */ 698757Sdg movl %esi,%eax /* phys address of ptd in proc 0 */ 699757Sdg movl %eax,%cr3 /* load ptd addr into mmu */ 700757Sdg movl %cr0,%eax /* get control word */ 701757Sdg orl $CR0_PE|CR0_PG,%eax /* enable paging */ 702757Sdg movl %eax,%cr0 /* and let's page NOW! */ 7034Srgrimes 704757Sdg pushl $begin /* jump to high mem */ 7054Srgrimes ret 7064Srgrimes 707570Srgrimesbegin: /* now running relocated at KERNBASE where the system is linked to run */ 708757Sdg movl _atdevphys,%edx /* get pte PA */ 709757Sdg subl _KPTphys,%edx /* remove base of ptes, now have phys offset */ 710757Sdg shll $PGSHIFT-2,%edx /* corresponding to virt offset */ 711757Sdg addl $KERNBASE,%edx /* add virtual base */ 712570Srgrimes movl %edx,_atdevbase 7133728Sphk 7143728Sphk#if N_SC > 0 7153728Sphk /* XXX: can't scinit relocate Crtat relative to atdevbase itself? */ 7163728Sphk .globl _Crtat /* XXX - locore should not know about */ 7173728Sphk movl _Crtat,%eax /* variables of device drivers (pccons)! */ 7183728Sphk subl $(KERNBASE+0xA0000),%eax 7194Srgrimes addl %eax,%edx 7204Srgrimes movl %edx,_Crtat 7213728Sphk#endif 7224Srgrimes 723757Sdg /* set up bootstrap stack - 48 bytes */ 724570Srgrimes movl $_kstack+UPAGES*NBPG-4*12,%esp /* bootstrap stack end location */ 725757Sdg xorl %eax,%eax /* mark end of frames */ 7264Srgrimes movl %eax,%ebp 727570Srgrimes movl _proc0paddr,%eax 728570Srgrimes movl %esi,PCB_CR3(%eax) 7294Srgrimes 730757Sdg#ifdef BDE_DEBUGGER 7314Srgrimes /* relocate debugger gdt entries */ 7324Srgrimes 733757Sdg movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 7344Srgrimes movl $9,%ecx 7354Srgrimesreloc_gdt: 7361321Sdg movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 737757Sdg addl $8,%eax /* now KERNBASE>>24 */ 7384Srgrimes loop reloc_gdt 7394Srgrimes 7404Srgrimes cmpl $0,_bdb_exists 7414Srgrimes je 1f 7424Srgrimes int $3 7434Srgrimes1: 7441321Sdg#endif /* BDE_DEBUGGER */ 7454Srgrimes 746608Srgrimes /* 747608Srgrimes * Skip over the page tables and the kernel stack 748608Srgrimes */ 749974Sdg lea ((1+UPAGES+1+NKPT)*NBPG)(%esi),%esi 750608Srgrimes 751757Sdg pushl %esi /* value of first for init386(first) */ 752757Sdg call _init386 /* wire 386 chip for unix operation */ 7531549Srgrimes popl %esi 754200Sdg 7551549Srgrimes .globl __ucodesel,__udatasel 7561549Srgrimes 7571549Srgrimes pushl $0 /* unused */ 7581549Srgrimes pushl __udatasel /* ss */ 7591549Srgrimes pushl $0 /* esp - filled in by execve() */ 7602500Sdg pushl $PSL_USERSET /* eflags (ring 0, int enab) */ 7611549Srgrimes pushl __ucodesel /* cs */ 7621549Srgrimes pushl $0 /* eip - filled in by execve() */ 7631549Srgrimes subl $(12*4),%esp /* space for rest of registers */ 7641549Srgrimes 7651549Srgrimes pushl %esp /* call main with frame pointer */ 766757Sdg call _main /* autoconfiguration, mountroot etc */ 7674Srgrimes 7681549Srgrimes addl $(13*4),%esp /* back to a frame we can return with */ 7691549Srgrimes 770134Sdg /* 771570Srgrimes * now we've run main() and determined what cpu-type we are, we can 772570Srgrimes * enable WP mode on i486 cpus and above. 7731058Sdg */ 7741058Sdg#if defined(I486_CPU) || defined(I586_CPU) 7751058Sdg cmpl $CPUCLASS_386,_cpu_class 7761058Sdg je 1f 7771058Sdg movl %cr0,%eax /* get control word */ 7781058Sdg orl $CR0_WP,%eax /* enable write protect for all modes */ 7791058Sdg movl %eax,%cr0 /* and do it */ 7801058Sdg#endif 7811058Sdg /* 782134Sdg * on return from main(), we are process 1 783134Sdg * set up address space and stack so that we can 'return' to user mode 784134Sdg */ 7851058Sdg1: 7864Srgrimes movl __ucodesel,%eax 7874Srgrimes movl __udatasel,%ecx 7881549Srgrimes 7894Srgrimes movl %cx,%ds 7904Srgrimes movl %cx,%es 791757Sdg movl %ax,%fs /* double map cs to fs */ 792757Sdg movl %cx,%gs /* and ds to gs */ 7931549Srgrimes iret /* goto user! */ 7944Srgrimes 7951549Srgrimes#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 7964Srgrimes 797200SdgNON_GPROF_ENTRY(sigcode) 798592Srgrimes call SIGF_HANDLER(%esp) 799757Sdg lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 800757Sdg /* copy at 8(%esp)) */ 8014Srgrimes pushl %eax 802757Sdg pushl %eax /* junk to fake return address */ 803757Sdg movl $103,%eax /* XXX sigreturn() */ 804757Sdg LCALL(0x7,0) /* enter kernel with args on stack */ 805757Sdg hlt /* never gets here */ 8064Srgrimes 8074Srgrimes .globl _szsigcode 8084Srgrimes_szsigcode: 8094Srgrimes .long _szsigcode-_sigcode 810