locore.s revision 4012
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 374012Sbde * $Id: locore.s,v 1.41 1994/10/26 21:52:25 bde Exp $ 384Srgrimes */ 394Srgrimes 404Srgrimes/* 41757Sdg * locore.s: FreeBSD machine support for the Intel 386 42757Sdg * originally from: locore.s, by William F. Jolitz 43757Sdg * 44757Sdg * Substantially rewritten by David Greenman, Rod Grimes, 45757Sdg * Bruce Evans, Wolfgang Solfrank, and many others. 464Srgrimes */ 474Srgrimes 482056Swollman#include "assym.s" /* system definitions */ 492056Swollman#include <machine/psl.h> /* processor status longword defs */ 502056Swollman#include <machine/pte.h> /* page table entry definitions */ 512056Swollman#include <sys/errno.h> /* error return codes */ 522056Swollman#include <machine/specialreg.h> /* x86 special registers */ 532056Swollman#include <machine/cputypes.h> /* x86 cpu type definitions */ 542056Swollman#include <sys/syscall.h> /* system call numbers */ 552056Swollman#include <machine/asmacros.h> /* miscellaneous asm macros */ 563489Sphk#include "apm.h" 573489Sphk#if NAPM > 0 583258Sdg#define ASM 593258Sdg#include <machine/apm_bios.h> 603258Sdg#include <machine/apm_segments.h> 613489Sphk#endif /* NAPM */ 624Srgrimes 634Srgrimes/* 64757Sdg * XXX 65757Sdg * 664Srgrimes * Note: This version greatly munged to avoid various assembler errors 674Srgrimes * that may be fixed in newer versions of gas. Perhaps newer versions 684Srgrimes * will have more pleasant appearance. 694Srgrimes */ 704Srgrimes 71200Sdg/* 724Srgrimes * PTmap is recursive pagemap at top of virtual address space. 734Srgrimes * Within PTmap, the page directory can be found (third indirection). 744Srgrimes */ 753861Sbde .globl _PTmap,_PTD,_PTDpde 76592Srgrimes .set _PTmap,PTDPTDI << PDRSHIFT 77592Srgrimes .set _PTD,_PTmap + (PTDPTDI * NBPG) 78757Sdg .set _PTDpde,_PTD + (PTDPTDI * PDESIZE) 79592Srgrimes 803861Sbde/* 813861Sbde * Sysmap is the base address of the kernel page tables. 823861Sbde * It is a bogus interface for kgdb and isn't used by the kernel itself. 833861Sbde */ 84608Srgrimes .set _Sysmap,_PTmap + (KPTDI * NBPG) 854Srgrimes 864Srgrimes/* 874Srgrimes * APTmap, APTD is the alternate recursive pagemap. 884Srgrimes * It's used when modifying another process's page tables. 894Srgrimes */ 90592Srgrimes .globl _APTmap,_APTD,_APTDpde 91592Srgrimes .set _APTmap,APTDPTDI << PDRSHIFT 92592Srgrimes .set _APTD,_APTmap + (APTDPTDI * NBPG) 93757Sdg .set _APTDpde,_PTD + (APTDPTDI * PDESIZE) 944Srgrimes 954Srgrimes/* 964Srgrimes * Access to each processes kernel stack is via a region of 974Srgrimes * per-process address space (at the beginning), immediatly above 984Srgrimes * the user process stack. 994Srgrimes */ 100570Srgrimes .set _kstack,USRSTACK 101134Sdg .globl _kstack 1024Srgrimes 103556Srgrimes/* 104556Srgrimes * Globals 105556Srgrimes */ 106556Srgrimes .data 107134Sdg 1083842Sdg .globl tmpstk 1093842Sdg .space 0x1000 /* space for tmpstk - temporary stack */ 1103842Sdgtmpstk: 1114012Sbde/* 1124012Sbde * Dummy frame at top of tmpstk to help debuggers print a nice stack trace. 1134012Sbde */ 1144012Sbde .long tmpstk+8 /* caller's %ebp */ 1154012Sbde .long _cpu_switch /* caller */ 1164012Sbde .long 0 /* %ebp == 0 should terminate trace */ 1174012Sbde .long _mvesp /* in case %ebp == 0 doesn't work ... */ 1184012Sbde .long 0x11111111, 0x22222222, 0x33333333, 0x44444444, 0x55555555 1193842Sdg 1203861Sbde .globl _boothowto,_bootdev 121134Sdg 1221998Swollman .globl _cpu,_cold,_atdevbase,_cpu_vendor,_cpu_id 1232783Ssos 124757Sdg_cpu: .long 0 /* are we 386, 386sx, or 486 */ 1252216Sbde_cpu_id: .long 0 /* stepping ID */ 1262216Sbde_cpu_vendor: .space 20 /* CPU origin code */ 127757Sdg_cold: .long 1 /* cold till we are not */ 128757Sdg_atdevbase: .long 0 /* location of start of iomem in virtual */ 129757Sdg_atdevphys: .long 0 /* location of device mapping ptes (phys) */ 1304Srgrimes 131757Sdg_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 132757Sdg 1333861Sbde .globl _IdlePTD 134757Sdg_IdlePTD: .long 0 /* phys addr of kernel PTD */ 1353861Sbde 136757Sdg_KPTphys: .long 0 /* phys addr of kernel page tables */ 1374Srgrimes 138757Sdg .globl _proc0paddr 139757Sdg_proc0paddr: .long 0 /* address of proc 0 address space */ 140134Sdg 141757Sdg#ifdef BDE_DEBUGGER 142757Sdg .globl _bdb_exists /* flag to indicate BDE debugger is available */ 1431321Sdg_bdb_exists: .long 0 144757Sdg#endif 1453489Sphk#if NAPM > 0 1463258Sdg .globl _apm_current_gdt_pdesc /* current GDT pseudo desc. */ 1473258Sdg_apm_current_gdt_pdesc: 1483314Sdg .word 0, 0, 0 149718Swollman 1503258Sdg .globl _bootstrap_gdt 1513258Sdg_bootstrap_gdt: 1523258Sdg .space SIZEOF_GDT * BOOTSTRAP_GDT_NUM 1533489Sphk#endif /* NAPM */ 154134Sdg 155556Srgrimes/* 156556Srgrimes * System Initialization 157556Srgrimes */ 1584Srgrimes .text 159134Sdg 160134Sdg/* 161200Sdg * btext: beginning of text section. 162200Sdg * Also the entry point (jumped to directly from the boot blocks). 163134Sdg */ 1641321SdgNON_GPROF_ENTRY(btext) 165757Sdg movw $0x1234,0x472 /* warm boot */ 1664Srgrimes jmp 1f 1673284Srgrimes /* 1683284Srgrimes * XXX now that we load at 1MB is this still really used? 1693284Srgrimes */ 1701321Sdg .org 0x500 /* space for BIOS variables */ 1714Srgrimes 1723284Srgrimes1: 1733384Srgrimes /* Set up a real frame, some day we will be doing returns */ 1743384Srgrimes pushl %ebp 1753384Srgrimes movl %esp, %ebp 1763384Srgrimes 1772512Sbde /* Don't trust what the BIOS gives for eflags. */ 1782512Sbde pushl $PSL_MBO 1792486Sdg popfl 1802486Sdg 1814Srgrimes /* 1823284Srgrimes * This code is called in different ways depending on what loaded 1833284Srgrimes * and started the kernel. This is used to detect how we get the 1843284Srgrimes * arguments from the other code and what we do with them. 1853284Srgrimes * 1863284Srgrimes * Old disk boot blocks: 1873284Srgrimes * (*btext)(howto, bootdev, cyloffset, esym); 1883284Srgrimes * [return address == 0, and can NOT be returned to] 1893284Srgrimes * [cyloffset was not supported by the FreeBSD boot code 1903284Srgrimes * and always passed in as 0] 1913284Srgrimes * [esym is also known as total in the boot code, and 1923284Srgrimes * was never properly supported by the FreeBSD boot code] 1933284Srgrimes * 1943284Srgrimes * Old diskless netboot code: 1953284Srgrimes * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 1963284Srgrimes * [return address != 0, and can NOT be returned to] 1973284Srgrimes * If we are being booted by this code it will NOT work, 1983284Srgrimes * so we are just going to halt if we find this case. 1993284Srgrimes * 2003284Srgrimes * New uniform boot code: 2013284Srgrimes * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 2023284Srgrimes * [return address != 0, and can be returned to] 2033284Srgrimes * 2043284Srgrimes * There may seem to be a lot of wasted arguments in here, but 2053384Srgrimes * that is so the newer boot code can still load very old kernels 2063384Srgrimes * and old boot code can load new kernels. 2074Srgrimes */ 2083284Srgrimes 2093284Srgrimes /* 2103284Srgrimes * The old style disk boot blocks fake a frame on the stack and 2113284Srgrimes * did an lret to get here. The frame on the stack has a return 2123284Srgrimes * address of 0. 2133284Srgrimes */ 2143384Srgrimes cmpl $0,4(%ebp) 2153284Srgrimes je 2f /* olddiskboot: */ 2163284Srgrimes 2173284Srgrimes /* 2183284Srgrimes * We have some form of return address, so this is either the 2193284Srgrimes * old diskless netboot code, or the new uniform code. That can 2203284Srgrimes * be detected by looking at the 5th argument, it if is 0 we 2213284Srgrimes * we are being booted by the new unifrom boot code. 2223284Srgrimes */ 2233384Srgrimes cmpl $0,24(%ebp) 2243284Srgrimes je 1f /* newboot: */ 2253284Srgrimes 2263284Srgrimes /* 2273284Srgrimes * Seems we have been loaded by the old diskless boot code, we 2283284Srgrimes * don't stand a chance of running as the diskless structure 2293284Srgrimes * changed considerably between the two, so just halt. 2303284Srgrimes */ 2313284Srgrimes hlt 2323284Srgrimes 2333284Srgrimes /* 2343384Srgrimes * We have been loaded by the new uniform boot code. 2353384Srgrimes * Lets check the bootinfo version, and if we do not understand 2363384Srgrimes * it we return to the loader with a status of 1 to indicate this error 2373284Srgrimes */ 2383284Srgrimes1: /* newboot: */ 2393384Srgrimes movl 28(%ebp),%ebx /* &bootinfo.version */ 2403384Srgrimes movl BOOTINFO_VERSION(%ebx),%eax 2413384Srgrimes cmpl $1,%eax /* We only understand version 1 */ 2423384Srgrimes je 1f 2433384Srgrimes movl $1,%eax /* Return status */ 2443384Srgrimes leave 2453384Srgrimes ret 2463284Srgrimes 2473384Srgrimes1: 2483284Srgrimes /* 2493384Srgrimes * If we have a kernelname copy it in 2503384Srgrimes */ 2513384Srgrimes movl BOOTINFO_KERNELNAME(%ebx),%esi 2523384Srgrimes cmpl $0,%esi 2533384Srgrimes je 1f /* No kernelname */ 2543384Srgrimes lea _kernelname-KERNBASE,%edi 2553384Srgrimes movl $MAXPATHLEN,%ecx /* Brute force!!! */ 2563384Srgrimes cld 2573384Srgrimes rep 2583384Srgrimes movsb 2593384Srgrimes 2603384Srgrimes1: 2613426Srgrimes#ifdef NFS 2623384Srgrimes /* 2633384Srgrimes * If we have a nfs_diskless structure copy it in 2643384Srgrimes */ 2653384Srgrimes movl BOOTINFO_NFS_DISKLESS(%ebx),%esi 2663384Srgrimes cmpl $0,%esi 2673384Srgrimes je 2f 2683384Srgrimes lea _nfs_diskless-KERNBASE,%edi 2693384Srgrimes movl $NFSDISKLESS_SIZE,%ecx 2703384Srgrimes cld 2713384Srgrimes rep 2723384Srgrimes movsb 2733795Sphk lea _nfs_diskless_valid-KERNBASE,%edi 2743795Sphk movl $1,(%edi) 2753406Sdg#endif 2763384Srgrimes 2773384Srgrimes /* 2783284Srgrimes * The old style disk boot. 2793284Srgrimes * (*btext)(howto, bootdev, cyloffset, esym); 2803384Srgrimes * Note that the newer boot code just falls into here to pick 2813384Srgrimes * up howto and bootdev, cyloffset and esym are no longer used 2823284Srgrimes */ 2833284Srgrimes2: /* olddiskboot: */ 2843384Srgrimes movl 8(%ebp),%eax 285570Srgrimes movl %eax,_boothowto-KERNBASE 2863384Srgrimes movl 12(%ebp),%eax 287570Srgrimes movl %eax,_bootdev-KERNBASE 2882783Ssos 2893489Sphk#if NAPM > 0 2903258Sdg /* 2913258Sdg * Setup APM BIOS: 2923258Sdg * 2933258Sdg * APM BIOS initialization should be done from real mode or V86 mode. 2943258Sdg * 2953258Sdg * (by HOSOKAWA, Tatsumi <hosokawa@mt.cs.keio.ac.jp>) 2963258Sdg */ 2974Srgrimes 2983258Sdg /* 2993258Sdg * Copy APM initializer under 1MB boundary: 3003258Sdg * 3013258Sdg * APM initializer program must switch the CPU to real mode. 3023258Sdg * But FreeBSD kernel runs above 1MB boundary. So we must 3033258Sdg * copy the initializer code to conventional memory. 3043258Sdg */ 3053258Sdg movl _apm_init_image_size-KERNBASE, %ecx /* size */ 3063258Sdg lea _apm_init_image-KERNBASE, %esi /* source */ 3073258Sdg movl $ APM_OURADDR, %edi /* destination */ 3083258Sdg cld 3093258Sdg rep 3103258Sdg movsb 3113258Sdg 3123258Sdg /* get GDT base */ 3133258Sdg sgdt _apm_current_gdt_pdesc-KERNBASE 3143258Sdg 3153258Sdg /* copy GDT to _bootstrap_gdt */ 3163258Sdg xorl %ecx, %ecx 3173258Sdg movw _apm_current_gdt_pdesc-KERNBASE, %cx 3183258Sdg movl _apm_current_gdt_pdesc-KERNBASE+2, %esi 3193258Sdg lea _bootstrap_gdt-KERNBASE, %edi 3203258Sdg cld 3213258Sdg rep 3223258Sdg movsb 3233258Sdg 3243258Sdg /* setup GDT pseudo descriptor */ 3253258Sdg movw $(SIZEOF_GDT*BOOTSTRAP_GDT_NUM), %ax 3263258Sdg movw %ax, _apm_current_gdt_pdesc-KERNBASE 3273258Sdg leal _bootstrap_gdt-KERNBASE, %eax 3283258Sdg movl %eax, _apm_current_gdt_pdesc-KERNBASE+2 3293258Sdg 3303258Sdg /* load new GDTR */ 3313258Sdg lgdt _apm_current_gdt_pdesc-KERNBASE 3323258Sdg 3333258Sdg /* setup GDT for APM initializer */ 3343258Sdg lea _bootstrap_gdt-KERNBASE, %ecx 3353258Sdg movl $(APM_OURADDR), %eax /* use %ax for 15..0 */ 3363258Sdg movl %eax, %ebx 3373258Sdg shrl $16, %ebx /* use %bl for 23..16 */ 3383258Sdg /* use %bh for 31..24 */ 3393258Sdg#define APM_SETUP_GDT(index, attrib) \ 3403258Sdg movl $(index), %si ; \ 3413258Sdg lea 0(%ecx,%esi,8), %edx ; \ 3423258Sdg movw $0xffff, (%edx) ; \ 3433258Sdg movw %ax, 2(%edx) ; \ 3443258Sdg movb %bl, 4(%edx) ; \ 3453258Sdg movw $(attrib), 5(%edx) ; \ 3463258Sdg movb %bh, 7(%edx) 3473258Sdg 3483258Sdg APM_SETUP_GDT(APM_INIT_CS_INDEX , CS32_ATTRIB) 3493258Sdg APM_SETUP_GDT(APM_INIT_DS_INDEX , DS32_ATTRIB) 3503258Sdg APM_SETUP_GDT(APM_INIT_CS16_INDEX, CS16_ATTRIB) 3513258Sdg 3523258Sdg /* 3533258Sdg * Call the initializer: 3543258Sdg * 3553258Sdg * direct intersegment call to conventional memory code 3563258Sdg */ 3573258Sdg .byte 0x9a /* actually, lcall $APM_INIT_CS_SEL, $0 */ 3583258Sdg .long 0 3593258Sdg .word APM_INIT_CS_SEL 3603258Sdg 3613258Sdg movw %ax, _apm_version-KERNBASE 3623258Sdg movl %ebx, _apm_cs_entry-KERNBASE 3633258Sdg movw %cx, _apm_cs32_base-KERNBASE 3643258Sdg shrl $16, %ecx 3653258Sdg movw %cx, _apm_cs16_base-KERNBASE 3663258Sdg movw %dx, _apm_ds_base-KERNBASE 3673258Sdg movw %si, _apm_cs_limit-KERNBASE 3683258Sdg shrl $16, %esi 3693258Sdg movw %si, _apm_ds_limit-KERNBASE 3703258Sdg movw %di, _apm_flags-KERNBASE 3713489Sphk#endif /* NAPM */ 3723258Sdg 3731998Swollman /* Find out our CPU type. */ 3741321Sdg 3751998Swollman /* Try to toggle alignment check flag; does not exist on 386. */ 3761998Swollman pushfl 3771998Swollman popl %eax 3781998Swollman movl %eax,%ecx 3791998Swollman orl $PSL_AC,%eax 3801998Swollman pushl %eax 3811998Swollman popfl 3821998Swollman pushfl 3831998Swollman popl %eax 3841998Swollman xorl %ecx,%eax 3851998Swollman andl $PSL_AC,%eax 3861998Swollman pushl %ecx 3871998Swollman popfl 3881998Swollman 3891998Swollman testl %eax,%eax 3901998Swollman jnz 1f 3911998Swollman movl $CPU_386,_cpu-KERNBASE 392556Srgrimes jmp 2f 3931998Swollman 3941998Swollman1: /* Try to toggle identification flag; does not exist on early 486s. */ 3951998Swollman pushfl 3961998Swollman popl %eax 3971998Swollman movl %eax,%ecx 3981998Swollman xorl $PSL_ID,%eax 3991998Swollman pushl %eax 4001998Swollman popfl 4011998Swollman pushfl 4021998Swollman popl %eax 4031998Swollman xorl %ecx,%eax 4041998Swollman andl $PSL_ID,%eax 4051998Swollman pushl %ecx 4061998Swollman popfl 4071998Swollman 4081998Swollman testl %eax,%eax 4091998Swollman jnz 1f 4101998Swollman movl $CPU_486,_cpu-KERNBASE 4112495Spst 4122495Spst /* check for Cyrix 486DLC -- based on check routine */ 4132495Spst /* documented in "Cx486SLC/e SMM Programmer's Guide" */ 4142495Spst xorw %dx,%dx 4152495Spst cmpw %dx,%dx # set flags to known state 4162495Spst pushfw 4172495Spst popw %cx # store flags in ecx 4182495Spst movw $0xffff,%ax 4192495Spst movw $0x0004,%bx 4202495Spst divw %bx 4212495Spst pushfw 4222495Spst popw %ax 4232495Spst andw $0x08d5,%ax # mask off important bits 4242495Spst andw $0x08d5,%cx 4252495Spst cmpw %ax,%cx 4262495Spst 4272495Spst jnz 2f # if flags changed, Intel chip 4282495Spst 4292495Spst movl $CPU_486DLC,_cpu-KERNBASE # set CPU value for Cyrix 4302495Spst movl $0x69727943,_cpu_vendor-KERNBASE # store vendor string 4312495Spst movw $0x0078,_cpu_vendor-KERNBASE+4 4322495Spst 4332495Spst invd # Start with guaranteed clean cache 4342495Spst /* Disable caching of the ISA hole only. */ 4352495Spst movb $CCR0,%al # Configuration Register index (CCR0) 4362495Spst outb %al,$0x22 4372495Spst inb $0x23,%al 4383117Spst orb $(CCR0_NC1|CCR0_BARB),%al 4392495Spst outb %al,$0x23 4402495Spst invd 4411998Swollman jmp 2f 4421998Swollman 4431998Swollman1: /* Use the `cpuid' instruction. */ 4441998Swollman xorl %eax,%eax 4451998Swollman .byte 0x0f,0xa2 # cpuid 0 4461998Swollman movl %ebx,_cpu_vendor-KERNBASE # store vendor string 4471998Swollman movl %edx,_cpu_vendor+4-KERNBASE 4481998Swollman movl %ecx,_cpu_vendor+8-KERNBASE 4491998Swollman movb $0,_cpu_vendor+12-KERNBASE 4501998Swollman 4511998Swollman movl $1,%eax 4521998Swollman .byte 0x0f,0xa2 # cpuid 1 4531998Swollman movl %eax,_cpu_id-KERNBASE # store cpu_id 4541998Swollman rorl $8,%eax # extract family type 4551998Swollman andl $15,%eax 4561998Swollman cmpl $5,%eax 4571998Swollman jae 1f 4581998Swollman 4591998Swollman /* less than Pentium; must be 486 */ 4601998Swollman movl $CPU_486,_cpu-KERNBASE 4611998Swollman jmp 2f 4621998Swollman 4631998Swollman1: movl $CPU_586,_cpu-KERNBASE 464556Srgrimes2: 465556Srgrimes 4664Srgrimes /* 4674Srgrimes * Finished with old stack; load new %esp now instead of later so 4684Srgrimes * we can trace this code without having to worry about the trace 4694Srgrimes * trap clobbering the memory test or the zeroing of the bss+bootstrap 4704Srgrimes * page tables. 4714Srgrimes * 4724Srgrimes * XXX - wdboot clears the bss after testing that this is safe. 4734Srgrimes * This is too wasteful - memory below 640K is scarce. The boot 4744Srgrimes * program should check: 4754Srgrimes * text+data <= &stack_variable - more_space_for_stack 4764Srgrimes * text+data+bss+pad+space_for_page_tables <= end_of_memory 4774Srgrimes * Oops, the gdt is in the carcass of the boot program so clearing 4784Srgrimes * the rest of memory is still not possible. 4794Srgrimes */ 480757Sdg movl $tmpstk-KERNBASE,%esp /* bootstrap stack end location */ 4814Srgrimes 482570Srgrimes/* 483570Srgrimes * Virtual address space of kernel: 484570Srgrimes * 485570Srgrimes * text | data | bss | [syms] | page dir | proc0 kernel stack | usr stk map | Sysmap 486974Sdg * pages: 1 UPAGES (2) 1 NKPT (7) 487570Srgrimes */ 488570Srgrimes 4894Srgrimes/* find end of kernel image */ 490570Srgrimes movl $_end-KERNBASE,%ecx 491757Sdg addl $NBPG-1,%ecx /* page align up */ 4924Srgrimes andl $~(NBPG-1),%ecx 4931321Sdg movl %ecx,%esi /* esi = start of free memory */ 494757Sdg movl %ecx,_KERNend-KERNBASE /* save end of kernel */ 4954Srgrimes 496757Sdg/* clear bss */ 497570Srgrimes movl $_edata-KERNBASE,%edi 498760Srgrimes subl %edi,%ecx /* get amount to clear */ 499757Sdg xorl %eax,%eax /* specify zero fill */ 5004Srgrimes cld 5014Srgrimes rep 5024Srgrimes stosb 5034Srgrimes 504608Srgrimes/* 505974Sdg * The value in esi is both the end of the kernel bss and a pointer to 506974Sdg * the kernel page directory, and is used by the rest of locore to build 507974Sdg * the tables. 508974Sdg * esi + 1(page dir) + 2(UPAGES) + 1(p0stack) + NKPT(number of kernel 509757Sdg * page table pages) is then passed on the stack to init386(first) as 510757Sdg * the value first. esi should ALWAYS be page aligned!! 511608Srgrimes */ 512757Sdg movl %esi,%ecx /* Get current first availiable address */ 513608Srgrimes 514757Sdg/* clear pagetables, page directory, stack, etc... */ 515757Sdg movl %esi,%edi /* base (page directory) */ 516974Sdg movl $((1+UPAGES+1+NKPT)*NBPG),%ecx /* amount to clear */ 517757Sdg xorl %eax,%eax /* specify zero fill */ 518757Sdg cld 519757Sdg rep 520757Sdg stosb 521757Sdg 522757Sdg/* physical address of Idle proc/kernel page directory */ 523570Srgrimes movl %esi,_IdlePTD-KERNBASE 5244Srgrimes 525592Srgrimes/* 526592Srgrimes * fillkpt 527592Srgrimes * eax = (page frame address | control | status) == pte 528592Srgrimes * ebx = address of page table 529592Srgrimes * ecx = how many pages to map 530592Srgrimes */ 5314Srgrimes#define fillkpt \ 5324Srgrimes1: movl %eax,(%ebx) ; \ 533570Srgrimes addl $NBPG,%eax ; /* increment physical address */ \ 5344Srgrimes addl $4,%ebx ; /* next pte */ \ 5354Srgrimes loop 1b ; 5364Srgrimes 5374Srgrimes/* 5384Srgrimes * Map Kernel 5394Srgrimes * 5404Srgrimes * First step - build page tables 5414Srgrimes */ 542757Sdg#if defined (KGDB) || defined (BDE_DEBUGGER) 543757Sdg movl _KERNend-KERNBASE,%ecx /* this much memory, */ 544757Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 545757Sdg#ifdef BDE_DEBUGGER 546757Sdg cmpl $0xa0,%ecx /* XXX - cover debugger pages */ 547200Sdg jae 1f 548200Sdg movl $0xa0,%ecx 549200Sdg1: 550757Sdg#endif /* BDE_DEBUGGER */ 5512512Sbde movl $PG_V|PG_KW,%eax /* kernel R/W, valid */ 552757Sdg lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 553757Sdg movl %ebx,_KPTphys-KERNBASE /* save in global */ 5544Srgrimes fillkpt 5554Srgrimes 556757Sdg#else /* !KGDB && !BDE_DEBUGGER */ 557757Sdg /* write protect kernel text (doesn't do a thing for 386's - only 486's) */ 558757Sdg movl $_etext-KERNBASE,%ecx /* get size of text */ 5593842Sdg addl $NBPG-1,%ecx /* round up to page */ 560757Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 561757Sdg movl $PG_V|PG_KR,%eax /* specify read only */ 5623842Sdg#if 0 5633842Sdg movl $_etext,%ecx /* get size of text */ 5643842Sdg subl $_btext,%ecx 5653842Sdg addl $NBPG-1,%ecx /* round up to page */ 5663842Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 5673842Sdg movl $_btext-KERNBASE,%eax /* get offset to physical memory */ 5683842Sdg orl $PG_V|PG_KR,%eax /* specify read only */ 5693842Sdg#endif 570757Sdg lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 571757Sdg movl %ebx,_KPTphys-KERNBASE /* save in global */ 572757Sdg fillkpt 573757Sdg 574757Sdg /* data and bss are r/w */ 575757Sdg andl $PG_FRAME,%eax /* strip to just addr of bss */ 576757Sdg movl _KERNend-KERNBASE,%ecx /* calculate size */ 577757Sdg subl %eax,%ecx 578757Sdg shrl $PGSHIFT,%ecx 579757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 580757Sdg fillkpt 5811321Sdg#endif /* KGDB || BDE_DEBUGGER */ 582757Sdg 583757Sdg/* now initialize the page dir, upages, p0stack PT, and page tables */ 584757Sdg 585974Sdg movl $(1+UPAGES+1+NKPT),%ecx /* number of PTEs */ 586757Sdg movl %esi,%eax /* phys address of PTD */ 587757Sdg andl $PG_FRAME,%eax /* convert to PFN, should be a NOP */ 5882512Sbde orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 589757Sdg movl %esi,%ebx /* calculate pte offset to ptd */ 590757Sdg shrl $PGSHIFT-2,%ebx 591757Sdg addl %esi,%ebx /* address of page directory */ 592757Sdg addl $((1+UPAGES+1)*NBPG),%ebx /* offset to kernel page tables */ 593757Sdg fillkpt 5941321Sdg 5954Srgrimes/* map I/O memory map */ 5964Srgrimes 597757Sdg movl _KPTphys-KERNBASE,%ebx /* base of kernel page tables */ 598757Sdg lea (0xa0 * PTESIZE)(%ebx),%ebx /* hardwire ISA hole at KERNBASE + 0xa0000 */ 599757Sdg movl $0x100-0xa0,%ecx /* for this many pte s, */ 6001046Sdg movl $(0xa0000|PG_V|PG_KW|PG_N),%eax /* valid, kernel read/write, non-cacheable */ 601757Sdg movl %ebx,_atdevphys-KERNBASE /* save phys addr of ptes */ 6024Srgrimes fillkpt 6034Srgrimes 6044Srgrimes /* map proc 0's kernel stack into user page table page */ 6054Srgrimes 606757Sdg movl $UPAGES,%ecx /* for this many pte s, */ 607757Sdg lea (1*NBPG)(%esi),%eax /* physical address in proc 0 */ 608757Sdg lea (KERNBASE)(%eax),%edx /* change into virtual addr */ 609757Sdg movl %edx,_proc0paddr-KERNBASE /* save VA for proc 0 init */ 610757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 611757Sdg lea ((1+UPAGES)*NBPG)(%esi),%ebx /* addr of stack page table in proc 0 */ 612757Sdg addl $(KSTKPTEOFF * PTESIZE),%ebx /* offset to kernel stack PTE */ 6134Srgrimes fillkpt 6144Srgrimes 6154Srgrimes/* 616757Sdg * Initialize kernel page table directory 6174Srgrimes */ 6184Srgrimes /* install a pde for temporary double map of bottom of VA */ 619757Sdg movl _KPTphys-KERNBASE,%eax 620757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 621757Sdg movl %eax,(%esi) /* which is where temp maps! */ 6224Srgrimes 623757Sdg /* initialize kernel pde's */ 624974Sdg movl $(NKPT),%ecx /* for this many PDEs */ 625757Sdg lea (KPTDI*PDESIZE)(%esi),%ebx /* offset of pde for kernel */ 6264Srgrimes fillkpt 6274Srgrimes 6284Srgrimes /* install a pde recursively mapping page directory as a page table! */ 629757Sdg movl %esi,%eax /* phys address of ptd in proc 0 */ 630757Sdg orl $PG_V|PG_KW,%eax /* pde entry is valid */ 631757Sdg movl %eax,PTDPTDI*PDESIZE(%esi) /* which is where PTmap maps! */ 6324Srgrimes 6334Srgrimes /* install a pde to map kernel stack for proc 0 */ 634757Sdg lea ((1+UPAGES)*NBPG)(%esi),%eax /* physical address of pt in proc 0 */ 635757Sdg orl $PG_V|PG_KW,%eax /* pde entry is valid */ 636757Sdg movl %eax,KSTKPTDI*PDESIZE(%esi) /* which is where kernel stack maps! */ 6374Srgrimes 638757Sdg#ifdef BDE_DEBUGGER 6394Srgrimes /* copy and convert stuff from old gdt and idt for debugger */ 6404Srgrimes 641757Sdg cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 6424Srgrimes jne 1f 643570Srgrimes movb $1,_bdb_exists-KERNBASE 6444Srgrimes1: 6454Srgrimes pushal 6464Srgrimes subl $2*6,%esp 6474Srgrimes 6484Srgrimes sgdt (%esp) 649757Sdg movl 2(%esp),%esi /* base address of current gdt */ 650570Srgrimes movl $_gdt-KERNBASE,%edi 6514Srgrimes movl %edi,2(%esp) 6524Srgrimes movl $8*18/4,%ecx 6531688Sdg cld 654757Sdg rep /* copy gdt */ 6554Srgrimes movsl 656570Srgrimes movl $_gdt-KERNBASE,-8+2(%edi) /* adjust gdt self-ptr */ 6574Srgrimes movb $0x92,-8+5(%edi) 6584Srgrimes 6594Srgrimes sidt 6(%esp) 660757Sdg movl 6+2(%esp),%esi /* base address of current idt */ 661757Sdg movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 6624Srgrimes movw 8(%esi),%ax 663570Srgrimes movl %eax,bdb_dbg_ljmp+1-KERNBASE /* ... immediate offset ... */ 6644Srgrimes movl 8+2(%esi),%eax 665570Srgrimes movw %ax,bdb_dbg_ljmp+5-KERNBASE /* ... and selector for ljmp */ 666757Sdg movl 24+4(%esi),%eax /* same for bpt descriptor */ 6674Srgrimes movw 24(%esi),%ax 668570Srgrimes movl %eax,bdb_bpt_ljmp+1-KERNBASE 6694Srgrimes movl 24+2(%esi),%eax 670570Srgrimes movw %ax,bdb_bpt_ljmp+5-KERNBASE 6714Srgrimes 672570Srgrimes movl $_idt-KERNBASE,%edi 6734Srgrimes movl %edi,6+2(%esp) 6744Srgrimes movl $8*4/4,%ecx 6751688Sdg cld 676757Sdg rep /* copy idt */ 6774Srgrimes movsl 6784Srgrimes 6794Srgrimes lgdt (%esp) 6804Srgrimes lidt 6(%esp) 6814Srgrimes 6824Srgrimes addl $2*6,%esp 6834Srgrimes popal 6841321Sdg#endif /* BDE_DEBUGGER */ 6854Srgrimes 686592Srgrimes /* load base of page directory and enable mapping */ 687757Sdg movl %esi,%eax /* phys address of ptd in proc 0 */ 688757Sdg movl %eax,%cr3 /* load ptd addr into mmu */ 689757Sdg movl %cr0,%eax /* get control word */ 690757Sdg orl $CR0_PE|CR0_PG,%eax /* enable paging */ 691757Sdg movl %eax,%cr0 /* and let's page NOW! */ 6924Srgrimes 693757Sdg pushl $begin /* jump to high mem */ 6944Srgrimes ret 6954Srgrimes 696570Srgrimesbegin: /* now running relocated at KERNBASE where the system is linked to run */ 697757Sdg movl _atdevphys,%edx /* get pte PA */ 698757Sdg subl _KPTphys,%edx /* remove base of ptes, now have phys offset */ 699757Sdg shll $PGSHIFT-2,%edx /* corresponding to virt offset */ 700757Sdg addl $KERNBASE,%edx /* add virtual base */ 701570Srgrimes movl %edx,_atdevbase 7023728Sphk 7033861Sbde#include "sc.h" 7043861Sbde#if NSC > 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