locore.s revision 3795
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 373795Sphk * $Id: locore.s,v 1.37 1994/10/20 00:07:47 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 106592Srgrimes .globl _boothowto,_bootdev,_curpcb 107134Sdg 1081998Swollman .globl _cpu,_cold,_atdevbase,_cpu_vendor,_cpu_id 1092783Ssos 1102783Ssos .globl _video_mode_ptr 1112783Ssos 112757Sdg_cpu: .long 0 /* are we 386, 386sx, or 486 */ 1132216Sbde_cpu_id: .long 0 /* stepping ID */ 1142216Sbde_cpu_vendor: .space 20 /* CPU origin code */ 1152783Ssos_video_mode_ptr: .long 0 116757Sdg_cold: .long 1 /* cold till we are not */ 117757Sdg_atdevbase: .long 0 /* location of start of iomem in virtual */ 118757Sdg_atdevphys: .long 0 /* location of device mapping ptes (phys) */ 1194Srgrimes 120757Sdg .globl _KERNend 121757Sdg_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 122757Sdg 123592Srgrimes .globl _IdlePTD,_KPTphys 124757Sdg_IdlePTD: .long 0 /* phys addr of kernel PTD */ 125757Sdg_KPTphys: .long 0 /* phys addr of kernel page tables */ 1264Srgrimes 127757Sdg .globl _proc0paddr 128757Sdg_proc0paddr: .long 0 /* address of proc 0 address space */ 129134Sdg 130757Sdg#ifdef BDE_DEBUGGER 131757Sdg .globl _bdb_exists /* flag to indicate BDE debugger is available */ 1321321Sdg_bdb_exists: .long 0 133757Sdg#endif 1343489Sphk#if NAPM > 0 1353258Sdg .globl _apm_current_gdt_pdesc /* current GDT pseudo desc. */ 1363258Sdg_apm_current_gdt_pdesc: 1373314Sdg .word 0, 0, 0 138718Swollman 1393258Sdg .globl _bootstrap_gdt 1403258Sdg_bootstrap_gdt: 1413258Sdg .space SIZEOF_GDT * BOOTSTRAP_GDT_NUM 1423489Sphk#endif /* NAPM */ 143757Sdg .globl tmpstk 144974Sdg .space 0x1000 1454Srgrimestmpstk: 146134Sdg 147134Sdg 148556Srgrimes/* 149556Srgrimes * System Initialization 150556Srgrimes */ 1514Srgrimes .text 152134Sdg 153134Sdg/* 154200Sdg * btext: beginning of text section. 155200Sdg * Also the entry point (jumped to directly from the boot blocks). 156134Sdg */ 1571321SdgNON_GPROF_ENTRY(btext) 158757Sdg movw $0x1234,0x472 /* warm boot */ 1594Srgrimes jmp 1f 1603284Srgrimes /* 1613284Srgrimes * XXX now that we load at 1MB is this still really used? 1623284Srgrimes */ 1631321Sdg .org 0x500 /* space for BIOS variables */ 1644Srgrimes 1653284Srgrimes1: 1663384Srgrimes /* Set up a real frame, some day we will be doing returns */ 1673384Srgrimes pushl %ebp 1683384Srgrimes movl %esp, %ebp 1693384Srgrimes 1702512Sbde /* Don't trust what the BIOS gives for eflags. */ 1712512Sbde pushl $PSL_MBO 1722486Sdg popfl 1732486Sdg 1744Srgrimes /* 1753284Srgrimes * This code is called in different ways depending on what loaded 1763284Srgrimes * and started the kernel. This is used to detect how we get the 1773284Srgrimes * arguments from the other code and what we do with them. 1783284Srgrimes * 1793284Srgrimes * Old disk boot blocks: 1803284Srgrimes * (*btext)(howto, bootdev, cyloffset, esym); 1813284Srgrimes * [return address == 0, and can NOT be returned to] 1823284Srgrimes * [cyloffset was not supported by the FreeBSD boot code 1833284Srgrimes * and always passed in as 0] 1843284Srgrimes * [esym is also known as total in the boot code, and 1853284Srgrimes * was never properly supported by the FreeBSD boot code] 1863284Srgrimes * 1873284Srgrimes * Old diskless netboot code: 1883284Srgrimes * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 1893284Srgrimes * [return address != 0, and can NOT be returned to] 1903284Srgrimes * If we are being booted by this code it will NOT work, 1913284Srgrimes * so we are just going to halt if we find this case. 1923284Srgrimes * 1933284Srgrimes * New uniform boot code: 1943284Srgrimes * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 1953284Srgrimes * [return address != 0, and can be returned to] 1963284Srgrimes * 1973284Srgrimes * There may seem to be a lot of wasted arguments in here, but 1983384Srgrimes * that is so the newer boot code can still load very old kernels 1993384Srgrimes * and old boot code can load new kernels. 2004Srgrimes */ 2013284Srgrimes 2023284Srgrimes /* 2033284Srgrimes * The old style disk boot blocks fake a frame on the stack and 2043284Srgrimes * did an lret to get here. The frame on the stack has a return 2053284Srgrimes * address of 0. 2063284Srgrimes */ 2073384Srgrimes cmpl $0,4(%ebp) 2083284Srgrimes je 2f /* olddiskboot: */ 2093284Srgrimes 2103284Srgrimes /* 2113284Srgrimes * We have some form of return address, so this is either the 2123284Srgrimes * old diskless netboot code, or the new uniform code. That can 2133284Srgrimes * be detected by looking at the 5th argument, it if is 0 we 2143284Srgrimes * we are being booted by the new unifrom boot code. 2153284Srgrimes */ 2163384Srgrimes cmpl $0,24(%ebp) 2173284Srgrimes je 1f /* newboot: */ 2183284Srgrimes 2193284Srgrimes /* 2203284Srgrimes * Seems we have been loaded by the old diskless boot code, we 2213284Srgrimes * don't stand a chance of running as the diskless structure 2223284Srgrimes * changed considerably between the two, so just halt. 2233284Srgrimes */ 2243284Srgrimes hlt 2253284Srgrimes 2263284Srgrimes /* 2273384Srgrimes * We have been loaded by the new uniform boot code. 2283384Srgrimes * Lets check the bootinfo version, and if we do not understand 2293384Srgrimes * it we return to the loader with a status of 1 to indicate this error 2303284Srgrimes */ 2313284Srgrimes1: /* newboot: */ 2323384Srgrimes movl 28(%ebp),%ebx /* &bootinfo.version */ 2333384Srgrimes movl BOOTINFO_VERSION(%ebx),%eax 2343384Srgrimes cmpl $1,%eax /* We only understand version 1 */ 2353384Srgrimes je 1f 2363384Srgrimes movl $1,%eax /* Return status */ 2373384Srgrimes leave 2383384Srgrimes ret 2393284Srgrimes 2403384Srgrimes1: 2413284Srgrimes /* 2423384Srgrimes * If we have a kernelname copy it in 2433384Srgrimes */ 2443384Srgrimes movl BOOTINFO_KERNELNAME(%ebx),%esi 2453384Srgrimes cmpl $0,%esi 2463384Srgrimes je 1f /* No kernelname */ 2473384Srgrimes lea _kernelname-KERNBASE,%edi 2483384Srgrimes movl $MAXPATHLEN,%ecx /* Brute force!!! */ 2493384Srgrimes cld 2503384Srgrimes rep 2513384Srgrimes movsb 2523384Srgrimes 2533384Srgrimes1: 2543426Srgrimes#ifdef NFS 2553384Srgrimes /* 2563384Srgrimes * If we have a nfs_diskless structure copy it in 2573384Srgrimes */ 2583384Srgrimes movl BOOTINFO_NFS_DISKLESS(%ebx),%esi 2593384Srgrimes cmpl $0,%esi 2603384Srgrimes je 2f 2613384Srgrimes lea _nfs_diskless-KERNBASE,%edi 2623384Srgrimes movl $NFSDISKLESS_SIZE,%ecx 2633384Srgrimes cld 2643384Srgrimes rep 2653384Srgrimes movsb 2663795Sphk lea _nfs_diskless_valid-KERNBASE,%edi 2673795Sphk movl $1,(%edi) 2683406Sdg#endif 2693384Srgrimes 2703384Srgrimes /* 2713284Srgrimes * The old style disk boot. 2723284Srgrimes * (*btext)(howto, bootdev, cyloffset, esym); 2733384Srgrimes * Note that the newer boot code just falls into here to pick 2743384Srgrimes * up howto and bootdev, cyloffset and esym are no longer used 2753284Srgrimes */ 2763284Srgrimes2: /* olddiskboot: */ 2773384Srgrimes movl 8(%ebp),%eax 278570Srgrimes movl %eax,_boothowto-KERNBASE 2793384Srgrimes movl 12(%ebp),%eax 280570Srgrimes movl %eax,_bootdev-KERNBASE 2812783Ssos 2822783Ssos /* get the BIOS video mode pointer */ 2832783Ssos movl $0x4a8, %ecx 2842783Ssos movl (%ecx), %eax 2852783Ssos movl %eax, %ecx 2862783Ssos shrl $12, %ecx 2872783Ssos andl $0xffff0000, %ecx 2882783Ssos andl $0x0000ffff, %eax 2892783Ssos orl %ecx, %eax 2902783Ssos movl (%eax), %eax 2912783Ssos movl %eax, %ecx 2922783Ssos shrl $12, %ecx 2932783Ssos andl $0xffff0000, %ecx 2942783Ssos andl $0x0000ffff, %eax 2952783Ssos orl %ecx, %eax 2962783Ssos addl $KERNBASE, %eax 2972783Ssos movl %eax, _video_mode_ptr-KERNBASE 2982783Ssos 2993489Sphk#if NAPM > 0 3003258Sdg /* 3013258Sdg * Setup APM BIOS: 3023258Sdg * 3033258Sdg * APM BIOS initialization should be done from real mode or V86 mode. 3043258Sdg * 3053258Sdg * (by HOSOKAWA, Tatsumi <hosokawa@mt.cs.keio.ac.jp>) 3063258Sdg */ 3074Srgrimes 3083258Sdg /* 3093258Sdg * Copy APM initializer under 1MB boundary: 3103258Sdg * 3113258Sdg * APM initializer program must switch the CPU to real mode. 3123258Sdg * But FreeBSD kernel runs above 1MB boundary. So we must 3133258Sdg * copy the initializer code to conventional memory. 3143258Sdg */ 3153258Sdg movl _apm_init_image_size-KERNBASE, %ecx /* size */ 3163258Sdg lea _apm_init_image-KERNBASE, %esi /* source */ 3173258Sdg movl $ APM_OURADDR, %edi /* destination */ 3183258Sdg cld 3193258Sdg rep 3203258Sdg movsb 3213258Sdg 3223258Sdg /* get GDT base */ 3233258Sdg sgdt _apm_current_gdt_pdesc-KERNBASE 3243258Sdg 3253258Sdg /* copy GDT to _bootstrap_gdt */ 3263258Sdg xorl %ecx, %ecx 3273258Sdg movw _apm_current_gdt_pdesc-KERNBASE, %cx 3283258Sdg movl _apm_current_gdt_pdesc-KERNBASE+2, %esi 3293258Sdg lea _bootstrap_gdt-KERNBASE, %edi 3303258Sdg cld 3313258Sdg rep 3323258Sdg movsb 3333258Sdg 3343258Sdg /* setup GDT pseudo descriptor */ 3353258Sdg movw $(SIZEOF_GDT*BOOTSTRAP_GDT_NUM), %ax 3363258Sdg movw %ax, _apm_current_gdt_pdesc-KERNBASE 3373258Sdg leal _bootstrap_gdt-KERNBASE, %eax 3383258Sdg movl %eax, _apm_current_gdt_pdesc-KERNBASE+2 3393258Sdg 3403258Sdg /* load new GDTR */ 3413258Sdg lgdt _apm_current_gdt_pdesc-KERNBASE 3423258Sdg 3433258Sdg /* setup GDT for APM initializer */ 3443258Sdg lea _bootstrap_gdt-KERNBASE, %ecx 3453258Sdg movl $(APM_OURADDR), %eax /* use %ax for 15..0 */ 3463258Sdg movl %eax, %ebx 3473258Sdg shrl $16, %ebx /* use %bl for 23..16 */ 3483258Sdg /* use %bh for 31..24 */ 3493258Sdg#define APM_SETUP_GDT(index, attrib) \ 3503258Sdg movl $(index), %si ; \ 3513258Sdg lea 0(%ecx,%esi,8), %edx ; \ 3523258Sdg movw $0xffff, (%edx) ; \ 3533258Sdg movw %ax, 2(%edx) ; \ 3543258Sdg movb %bl, 4(%edx) ; \ 3553258Sdg movw $(attrib), 5(%edx) ; \ 3563258Sdg movb %bh, 7(%edx) 3573258Sdg 3583258Sdg APM_SETUP_GDT(APM_INIT_CS_INDEX , CS32_ATTRIB) 3593258Sdg APM_SETUP_GDT(APM_INIT_DS_INDEX , DS32_ATTRIB) 3603258Sdg APM_SETUP_GDT(APM_INIT_CS16_INDEX, CS16_ATTRIB) 3613258Sdg 3623258Sdg /* 3633258Sdg * Call the initializer: 3643258Sdg * 3653258Sdg * direct intersegment call to conventional memory code 3663258Sdg */ 3673258Sdg .byte 0x9a /* actually, lcall $APM_INIT_CS_SEL, $0 */ 3683258Sdg .long 0 3693258Sdg .word APM_INIT_CS_SEL 3703258Sdg 3713258Sdg movw %ax, _apm_version-KERNBASE 3723258Sdg movl %ebx, _apm_cs_entry-KERNBASE 3733258Sdg movw %cx, _apm_cs32_base-KERNBASE 3743258Sdg shrl $16, %ecx 3753258Sdg movw %cx, _apm_cs16_base-KERNBASE 3763258Sdg movw %dx, _apm_ds_base-KERNBASE 3773258Sdg movw %si, _apm_cs_limit-KERNBASE 3783258Sdg shrl $16, %esi 3793258Sdg movw %si, _apm_ds_limit-KERNBASE 3803258Sdg movw %di, _apm_flags-KERNBASE 3813489Sphk#endif /* NAPM */ 3823258Sdg 3831998Swollman /* Find out our CPU type. */ 3841321Sdg 3851998Swollman /* Try to toggle alignment check flag; does not exist on 386. */ 3861998Swollman pushfl 3871998Swollman popl %eax 3881998Swollman movl %eax,%ecx 3891998Swollman orl $PSL_AC,%eax 3901998Swollman pushl %eax 3911998Swollman popfl 3921998Swollman pushfl 3931998Swollman popl %eax 3941998Swollman xorl %ecx,%eax 3951998Swollman andl $PSL_AC,%eax 3961998Swollman pushl %ecx 3971998Swollman popfl 3981998Swollman 3991998Swollman testl %eax,%eax 4001998Swollman jnz 1f 4011998Swollman movl $CPU_386,_cpu-KERNBASE 402556Srgrimes jmp 2f 4031998Swollman 4041998Swollman1: /* Try to toggle identification flag; does not exist on early 486s. */ 4051998Swollman pushfl 4061998Swollman popl %eax 4071998Swollman movl %eax,%ecx 4081998Swollman xorl $PSL_ID,%eax 4091998Swollman pushl %eax 4101998Swollman popfl 4111998Swollman pushfl 4121998Swollman popl %eax 4131998Swollman xorl %ecx,%eax 4141998Swollman andl $PSL_ID,%eax 4151998Swollman pushl %ecx 4161998Swollman popfl 4171998Swollman 4181998Swollman testl %eax,%eax 4191998Swollman jnz 1f 4201998Swollman movl $CPU_486,_cpu-KERNBASE 4212495Spst 4222495Spst /* check for Cyrix 486DLC -- based on check routine */ 4232495Spst /* documented in "Cx486SLC/e SMM Programmer's Guide" */ 4242495Spst xorw %dx,%dx 4252495Spst cmpw %dx,%dx # set flags to known state 4262495Spst pushfw 4272495Spst popw %cx # store flags in ecx 4282495Spst movw $0xffff,%ax 4292495Spst movw $0x0004,%bx 4302495Spst divw %bx 4312495Spst pushfw 4322495Spst popw %ax 4332495Spst andw $0x08d5,%ax # mask off important bits 4342495Spst andw $0x08d5,%cx 4352495Spst cmpw %ax,%cx 4362495Spst 4372495Spst jnz 2f # if flags changed, Intel chip 4382495Spst 4392495Spst movl $CPU_486DLC,_cpu-KERNBASE # set CPU value for Cyrix 4402495Spst movl $0x69727943,_cpu_vendor-KERNBASE # store vendor string 4412495Spst movw $0x0078,_cpu_vendor-KERNBASE+4 4422495Spst 4432495Spst invd # Start with guaranteed clean cache 4442495Spst /* Disable caching of the ISA hole only. */ 4452495Spst movb $CCR0,%al # Configuration Register index (CCR0) 4462495Spst outb %al,$0x22 4472495Spst inb $0x23,%al 4483117Spst orb $(CCR0_NC1|CCR0_BARB),%al 4492495Spst outb %al,$0x23 4502495Spst invd 4511998Swollman jmp 2f 4521998Swollman 4531998Swollman1: /* Use the `cpuid' instruction. */ 4541998Swollman xorl %eax,%eax 4551998Swollman .byte 0x0f,0xa2 # cpuid 0 4561998Swollman movl %ebx,_cpu_vendor-KERNBASE # store vendor string 4571998Swollman movl %edx,_cpu_vendor+4-KERNBASE 4581998Swollman movl %ecx,_cpu_vendor+8-KERNBASE 4591998Swollman movb $0,_cpu_vendor+12-KERNBASE 4601998Swollman 4611998Swollman movl $1,%eax 4621998Swollman .byte 0x0f,0xa2 # cpuid 1 4631998Swollman movl %eax,_cpu_id-KERNBASE # store cpu_id 4641998Swollman rorl $8,%eax # extract family type 4651998Swollman andl $15,%eax 4661998Swollman cmpl $5,%eax 4671998Swollman jae 1f 4681998Swollman 4691998Swollman /* less than Pentium; must be 486 */ 4701998Swollman movl $CPU_486,_cpu-KERNBASE 4711998Swollman jmp 2f 4721998Swollman 4731998Swollman1: movl $CPU_586,_cpu-KERNBASE 474556Srgrimes2: 475556Srgrimes 4764Srgrimes /* 4774Srgrimes * Finished with old stack; load new %esp now instead of later so 4784Srgrimes * we can trace this code without having to worry about the trace 4794Srgrimes * trap clobbering the memory test or the zeroing of the bss+bootstrap 4804Srgrimes * page tables. 4814Srgrimes * 4824Srgrimes * XXX - wdboot clears the bss after testing that this is safe. 4834Srgrimes * This is too wasteful - memory below 640K is scarce. The boot 4844Srgrimes * program should check: 4854Srgrimes * text+data <= &stack_variable - more_space_for_stack 4864Srgrimes * text+data+bss+pad+space_for_page_tables <= end_of_memory 4874Srgrimes * Oops, the gdt is in the carcass of the boot program so clearing 4884Srgrimes * the rest of memory is still not possible. 4894Srgrimes */ 490757Sdg movl $tmpstk-KERNBASE,%esp /* bootstrap stack end location */ 4914Srgrimes 492570Srgrimes/* 493570Srgrimes * Virtual address space of kernel: 494570Srgrimes * 495570Srgrimes * text | data | bss | [syms] | page dir | proc0 kernel stack | usr stk map | Sysmap 496974Sdg * pages: 1 UPAGES (2) 1 NKPT (7) 497570Srgrimes */ 498570Srgrimes 4994Srgrimes/* find end of kernel image */ 500570Srgrimes movl $_end-KERNBASE,%ecx 501757Sdg addl $NBPG-1,%ecx /* page align up */ 5024Srgrimes andl $~(NBPG-1),%ecx 5031321Sdg movl %ecx,%esi /* esi = start of free memory */ 504757Sdg movl %ecx,_KERNend-KERNBASE /* save end of kernel */ 5054Srgrimes 506757Sdg/* clear bss */ 507570Srgrimes movl $_edata-KERNBASE,%edi 508760Srgrimes subl %edi,%ecx /* get amount to clear */ 509757Sdg xorl %eax,%eax /* specify zero fill */ 5104Srgrimes cld 5114Srgrimes rep 5124Srgrimes stosb 5134Srgrimes 514608Srgrimes/* 515974Sdg * The value in esi is both the end of the kernel bss and a pointer to 516974Sdg * the kernel page directory, and is used by the rest of locore to build 517974Sdg * the tables. 518974Sdg * esi + 1(page dir) + 2(UPAGES) + 1(p0stack) + NKPT(number of kernel 519757Sdg * page table pages) is then passed on the stack to init386(first) as 520757Sdg * the value first. esi should ALWAYS be page aligned!! 521608Srgrimes */ 522757Sdg movl %esi,%ecx /* Get current first availiable address */ 523608Srgrimes 524757Sdg/* clear pagetables, page directory, stack, etc... */ 525757Sdg movl %esi,%edi /* base (page directory) */ 526974Sdg movl $((1+UPAGES+1+NKPT)*NBPG),%ecx /* amount to clear */ 527757Sdg xorl %eax,%eax /* specify zero fill */ 528757Sdg cld 529757Sdg rep 530757Sdg stosb 531757Sdg 532757Sdg/* physical address of Idle proc/kernel page directory */ 533570Srgrimes movl %esi,_IdlePTD-KERNBASE 5344Srgrimes 535592Srgrimes/* 536592Srgrimes * fillkpt 537592Srgrimes * eax = (page frame address | control | status) == pte 538592Srgrimes * ebx = address of page table 539592Srgrimes * ecx = how many pages to map 540592Srgrimes */ 5414Srgrimes#define fillkpt \ 5424Srgrimes1: movl %eax,(%ebx) ; \ 543570Srgrimes addl $NBPG,%eax ; /* increment physical address */ \ 5444Srgrimes addl $4,%ebx ; /* next pte */ \ 5454Srgrimes loop 1b ; 5464Srgrimes 5474Srgrimes/* 5484Srgrimes * Map Kernel 5494Srgrimes * 5504Srgrimes * First step - build page tables 5514Srgrimes */ 552757Sdg#if defined (KGDB) || defined (BDE_DEBUGGER) 553757Sdg movl _KERNend-KERNBASE,%ecx /* this much memory, */ 554757Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 555757Sdg#ifdef BDE_DEBUGGER 556757Sdg cmpl $0xa0,%ecx /* XXX - cover debugger pages */ 557200Sdg jae 1f 558200Sdg movl $0xa0,%ecx 559200Sdg1: 560757Sdg#endif /* BDE_DEBUGGER */ 5612512Sbde movl $PG_V|PG_KW,%eax /* kernel R/W, valid */ 562757Sdg lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 563757Sdg movl %ebx,_KPTphys-KERNBASE /* save in global */ 5644Srgrimes fillkpt 5654Srgrimes 566757Sdg#else /* !KGDB && !BDE_DEBUGGER */ 567757Sdg /* write protect kernel text (doesn't do a thing for 386's - only 486's) */ 568757Sdg movl $_etext-KERNBASE,%ecx /* get size of text */ 569757Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 570757Sdg movl $PG_V|PG_KR,%eax /* specify read only */ 571757Sdg lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 572757Sdg movl %ebx,_KPTphys-KERNBASE /* save in global */ 573757Sdg fillkpt 574757Sdg 575757Sdg /* data and bss are r/w */ 576757Sdg andl $PG_FRAME,%eax /* strip to just addr of bss */ 577757Sdg movl _KERNend-KERNBASE,%ecx /* calculate size */ 578757Sdg subl %eax,%ecx 579757Sdg shrl $PGSHIFT,%ecx 580757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 581757Sdg fillkpt 5821321Sdg#endif /* KGDB || BDE_DEBUGGER */ 583757Sdg 584757Sdg/* now initialize the page dir, upages, p0stack PT, and page tables */ 585757Sdg 586974Sdg movl $(1+UPAGES+1+NKPT),%ecx /* number of PTEs */ 587757Sdg movl %esi,%eax /* phys address of PTD */ 588757Sdg andl $PG_FRAME,%eax /* convert to PFN, should be a NOP */ 5892512Sbde orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 590757Sdg movl %esi,%ebx /* calculate pte offset to ptd */ 591757Sdg shrl $PGSHIFT-2,%ebx 592757Sdg addl %esi,%ebx /* address of page directory */ 593757Sdg addl $((1+UPAGES+1)*NBPG),%ebx /* offset to kernel page tables */ 594757Sdg fillkpt 5951321Sdg 5964Srgrimes/* map I/O memory map */ 5974Srgrimes 598757Sdg movl _KPTphys-KERNBASE,%ebx /* base of kernel page tables */ 599757Sdg lea (0xa0 * PTESIZE)(%ebx),%ebx /* hardwire ISA hole at KERNBASE + 0xa0000 */ 600757Sdg movl $0x100-0xa0,%ecx /* for this many pte s, */ 6011046Sdg movl $(0xa0000|PG_V|PG_KW|PG_N),%eax /* valid, kernel read/write, non-cacheable */ 602757Sdg movl %ebx,_atdevphys-KERNBASE /* save phys addr of ptes */ 6034Srgrimes fillkpt 6044Srgrimes 6054Srgrimes /* map proc 0's kernel stack into user page table page */ 6064Srgrimes 607757Sdg movl $UPAGES,%ecx /* for this many pte s, */ 608757Sdg lea (1*NBPG)(%esi),%eax /* physical address in proc 0 */ 609757Sdg lea (KERNBASE)(%eax),%edx /* change into virtual addr */ 610757Sdg movl %edx,_proc0paddr-KERNBASE /* save VA for proc 0 init */ 611757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 612757Sdg lea ((1+UPAGES)*NBPG)(%esi),%ebx /* addr of stack page table in proc 0 */ 613757Sdg addl $(KSTKPTEOFF * PTESIZE),%ebx /* offset to kernel stack PTE */ 6144Srgrimes fillkpt 6154Srgrimes 6164Srgrimes/* 617757Sdg * Initialize kernel page table directory 6184Srgrimes */ 6194Srgrimes /* install a pde for temporary double map of bottom of VA */ 620757Sdg movl _KPTphys-KERNBASE,%eax 621757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 622757Sdg movl %eax,(%esi) /* which is where temp maps! */ 6234Srgrimes 624757Sdg /* initialize kernel pde's */ 625974Sdg movl $(NKPT),%ecx /* for this many PDEs */ 626757Sdg lea (KPTDI*PDESIZE)(%esi),%ebx /* offset of pde for kernel */ 6274Srgrimes fillkpt 6284Srgrimes 6294Srgrimes /* install a pde recursively mapping page directory as a page table! */ 630757Sdg movl %esi,%eax /* phys address of ptd in proc 0 */ 631757Sdg orl $PG_V|PG_KW,%eax /* pde entry is valid */ 632757Sdg movl %eax,PTDPTDI*PDESIZE(%esi) /* which is where PTmap maps! */ 6334Srgrimes 6344Srgrimes /* install a pde to map kernel stack for proc 0 */ 635757Sdg lea ((1+UPAGES)*NBPG)(%esi),%eax /* physical address of pt in proc 0 */ 636757Sdg orl $PG_V|PG_KW,%eax /* pde entry is valid */ 637757Sdg movl %eax,KSTKPTDI*PDESIZE(%esi) /* which is where kernel stack maps! */ 6384Srgrimes 639757Sdg#ifdef BDE_DEBUGGER 6404Srgrimes /* copy and convert stuff from old gdt and idt for debugger */ 6414Srgrimes 642757Sdg cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 6434Srgrimes jne 1f 644570Srgrimes movb $1,_bdb_exists-KERNBASE 6454Srgrimes1: 6464Srgrimes pushal 6474Srgrimes subl $2*6,%esp 6484Srgrimes 6494Srgrimes sgdt (%esp) 650757Sdg movl 2(%esp),%esi /* base address of current gdt */ 651570Srgrimes movl $_gdt-KERNBASE,%edi 6524Srgrimes movl %edi,2(%esp) 6534Srgrimes movl $8*18/4,%ecx 6541688Sdg cld 655757Sdg rep /* copy gdt */ 6564Srgrimes movsl 657570Srgrimes movl $_gdt-KERNBASE,-8+2(%edi) /* adjust gdt self-ptr */ 6584Srgrimes movb $0x92,-8+5(%edi) 6594Srgrimes 6604Srgrimes sidt 6(%esp) 661757Sdg movl 6+2(%esp),%esi /* base address of current idt */ 662757Sdg movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 6634Srgrimes movw 8(%esi),%ax 664570Srgrimes movl %eax,bdb_dbg_ljmp+1-KERNBASE /* ... immediate offset ... */ 6654Srgrimes movl 8+2(%esi),%eax 666570Srgrimes movw %ax,bdb_dbg_ljmp+5-KERNBASE /* ... and selector for ljmp */ 667757Sdg movl 24+4(%esi),%eax /* same for bpt descriptor */ 6684Srgrimes movw 24(%esi),%ax 669570Srgrimes movl %eax,bdb_bpt_ljmp+1-KERNBASE 6704Srgrimes movl 24+2(%esi),%eax 671570Srgrimes movw %ax,bdb_bpt_ljmp+5-KERNBASE 6724Srgrimes 673570Srgrimes movl $_idt-KERNBASE,%edi 6744Srgrimes movl %edi,6+2(%esp) 6754Srgrimes movl $8*4/4,%ecx 6761688Sdg cld 677757Sdg rep /* copy idt */ 6784Srgrimes movsl 6794Srgrimes 6804Srgrimes lgdt (%esp) 6814Srgrimes lidt 6(%esp) 6824Srgrimes 6834Srgrimes addl $2*6,%esp 6844Srgrimes popal 6851321Sdg#endif /* BDE_DEBUGGER */ 6864Srgrimes 687592Srgrimes /* load base of page directory and enable mapping */ 688757Sdg movl %esi,%eax /* phys address of ptd in proc 0 */ 689757Sdg movl %eax,%cr3 /* load ptd addr into mmu */ 690757Sdg movl %cr0,%eax /* get control word */ 691757Sdg orl $CR0_PE|CR0_PG,%eax /* enable paging */ 692757Sdg movl %eax,%cr0 /* and let's page NOW! */ 6934Srgrimes 694757Sdg pushl $begin /* jump to high mem */ 6954Srgrimes ret 6964Srgrimes 697570Srgrimesbegin: /* now running relocated at KERNBASE where the system is linked to run */ 698757Sdg movl _atdevphys,%edx /* get pte PA */ 699757Sdg subl _KPTphys,%edx /* remove base of ptes, now have phys offset */ 700757Sdg shll $PGSHIFT-2,%edx /* corresponding to virt offset */ 701757Sdg addl $KERNBASE,%edx /* add virtual base */ 702570Srgrimes movl %edx,_atdevbase 7033728Sphk 7043728Sphk#if N_SC > 0 7053728Sphk /* XXX: can't scinit relocate Crtat relative to atdevbase itself? */ 7063728Sphk .globl _Crtat /* XXX - locore should not know about */ 7073728Sphk movl _Crtat,%eax /* variables of device drivers (pccons)! */ 7083728Sphk subl $(KERNBASE+0xA0000),%eax 7094Srgrimes addl %eax,%edx 7104Srgrimes movl %edx,_Crtat 7113728Sphk#endif 7124Srgrimes 713757Sdg /* set up bootstrap stack - 48 bytes */ 714570Srgrimes movl $_kstack+UPAGES*NBPG-4*12,%esp /* bootstrap stack end location */ 715757Sdg xorl %eax,%eax /* mark end of frames */ 7164Srgrimes movl %eax,%ebp 717570Srgrimes movl _proc0paddr,%eax 718570Srgrimes movl %esi,PCB_CR3(%eax) 7194Srgrimes 720757Sdg#ifdef BDE_DEBUGGER 7214Srgrimes /* relocate debugger gdt entries */ 7224Srgrimes 723757Sdg movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 7244Srgrimes movl $9,%ecx 7254Srgrimesreloc_gdt: 7261321Sdg movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 727757Sdg addl $8,%eax /* now KERNBASE>>24 */ 7284Srgrimes loop reloc_gdt 7294Srgrimes 7304Srgrimes cmpl $0,_bdb_exists 7314Srgrimes je 1f 7324Srgrimes int $3 7334Srgrimes1: 7341321Sdg#endif /* BDE_DEBUGGER */ 7354Srgrimes 736608Srgrimes /* 737608Srgrimes * Skip over the page tables and the kernel stack 738608Srgrimes */ 739974Sdg lea ((1+UPAGES+1+NKPT)*NBPG)(%esi),%esi 740608Srgrimes 741757Sdg pushl %esi /* value of first for init386(first) */ 742757Sdg call _init386 /* wire 386 chip for unix operation */ 7431549Srgrimes popl %esi 744200Sdg 7451549Srgrimes .globl __ucodesel,__udatasel 7461549Srgrimes 7471549Srgrimes pushl $0 /* unused */ 7481549Srgrimes pushl __udatasel /* ss */ 7491549Srgrimes pushl $0 /* esp - filled in by execve() */ 7502500Sdg pushl $PSL_USERSET /* eflags (ring 0, int enab) */ 7511549Srgrimes pushl __ucodesel /* cs */ 7521549Srgrimes pushl $0 /* eip - filled in by execve() */ 7531549Srgrimes subl $(12*4),%esp /* space for rest of registers */ 7541549Srgrimes 7551549Srgrimes pushl %esp /* call main with frame pointer */ 756757Sdg call _main /* autoconfiguration, mountroot etc */ 7574Srgrimes 7581549Srgrimes addl $(13*4),%esp /* back to a frame we can return with */ 7591549Srgrimes 760134Sdg /* 761570Srgrimes * now we've run main() and determined what cpu-type we are, we can 762570Srgrimes * enable WP mode on i486 cpus and above. 7631058Sdg */ 7641058Sdg#if defined(I486_CPU) || defined(I586_CPU) 7651058Sdg cmpl $CPUCLASS_386,_cpu_class 7661058Sdg je 1f 7671058Sdg movl %cr0,%eax /* get control word */ 7681058Sdg orl $CR0_WP,%eax /* enable write protect for all modes */ 7691058Sdg movl %eax,%cr0 /* and do it */ 7701058Sdg#endif 7711058Sdg /* 772134Sdg * on return from main(), we are process 1 773134Sdg * set up address space and stack so that we can 'return' to user mode 774134Sdg */ 7751058Sdg1: 7764Srgrimes movl __ucodesel,%eax 7774Srgrimes movl __udatasel,%ecx 7781549Srgrimes 7794Srgrimes movl %cx,%ds 7804Srgrimes movl %cx,%es 781757Sdg movl %ax,%fs /* double map cs to fs */ 782757Sdg movl %cx,%gs /* and ds to gs */ 7831549Srgrimes iret /* goto user! */ 7844Srgrimes 7851549Srgrimes#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 7864Srgrimes 787200SdgNON_GPROF_ENTRY(sigcode) 788592Srgrimes call SIGF_HANDLER(%esp) 789757Sdg lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 790757Sdg /* copy at 8(%esp)) */ 7914Srgrimes pushl %eax 792757Sdg pushl %eax /* junk to fake return address */ 793757Sdg movl $103,%eax /* XXX sigreturn() */ 794757Sdg LCALL(0x7,0) /* enter kernel with args on stack */ 795757Sdg hlt /* never gets here */ 7964Srgrimes 7974Srgrimes .globl _szsigcode 7984Srgrimes_szsigcode: 7994Srgrimes .long _szsigcode-_sigcode 800