locore.s revision 4600
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 374600Sphk * $Id: locore.s,v 1.44 1994/11/06 22:18:45 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 "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 1224600Sphk .globl _cpu,_cold,_atdevbase,_cpu_vendor,_cpu_id,_bootinfo 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 */ 1274600Sphk_bootinfo: .space BOOTINFO_SIZE /* the bootstrapper knew it! */ 128757Sdg_cold: .long 1 /* cold till we are not */ 129757Sdg_atdevbase: .long 0 /* location of start of iomem in virtual */ 130757Sdg_atdevphys: .long 0 /* location of device mapping ptes (phys) */ 1314Srgrimes 132757Sdg_KERNend: .long 0 /* phys addr end of kernel (just after bss) */ 133757Sdg 1343861Sbde .globl _IdlePTD 135757Sdg_IdlePTD: .long 0 /* phys addr of kernel PTD */ 1363861Sbde 137757Sdg_KPTphys: .long 0 /* phys addr of kernel page tables */ 1384Srgrimes 139757Sdg .globl _proc0paddr 140757Sdg_proc0paddr: .long 0 /* address of proc 0 address space */ 141134Sdg 142757Sdg#ifdef BDE_DEBUGGER 143757Sdg .globl _bdb_exists /* flag to indicate BDE debugger is available */ 1441321Sdg_bdb_exists: .long 0 145757Sdg#endif 1463489Sphk#if NAPM > 0 1473258Sdg .globl _apm_current_gdt_pdesc /* current GDT pseudo desc. */ 1483258Sdg_apm_current_gdt_pdesc: 1493314Sdg .word 0, 0, 0 150718Swollman 1513258Sdg .globl _bootstrap_gdt 1523258Sdg_bootstrap_gdt: 1533258Sdg .space SIZEOF_GDT * BOOTSTRAP_GDT_NUM 1543489Sphk#endif /* NAPM */ 155134Sdg 156556Srgrimes/* 157556Srgrimes * System Initialization 158556Srgrimes */ 1594Srgrimes .text 160134Sdg 161134Sdg/* 162200Sdg * btext: beginning of text section. 163200Sdg * Also the entry point (jumped to directly from the boot blocks). 164134Sdg */ 1651321SdgNON_GPROF_ENTRY(btext) 166757Sdg movw $0x1234,0x472 /* warm boot */ 1674Srgrimes jmp 1f 1683284Srgrimes /* 1693284Srgrimes * XXX now that we load at 1MB is this still really used? 1703284Srgrimes */ 1711321Sdg .org 0x500 /* space for BIOS variables */ 1724Srgrimes 1733284Srgrimes1: 1743384Srgrimes /* Set up a real frame, some day we will be doing returns */ 1753384Srgrimes pushl %ebp 1763384Srgrimes movl %esp, %ebp 1773384Srgrimes 1782512Sbde /* Don't trust what the BIOS gives for eflags. */ 1792512Sbde pushl $PSL_MBO 1802486Sdg popfl 1812486Sdg 1824217Sphk /* Don't trust what the BIOS gives for %fs and %gs. */ 1834217Sphk mov %ds, %ax 1844217Sphk mov %ax, %fs 1854217Sphk mov %ax, %gs 1864217Sphk 1874Srgrimes /* 1883284Srgrimes * This code is called in different ways depending on what loaded 1893284Srgrimes * and started the kernel. This is used to detect how we get the 1903284Srgrimes * arguments from the other code and what we do with them. 1913284Srgrimes * 1923284Srgrimes * Old disk boot blocks: 1933284Srgrimes * (*btext)(howto, bootdev, cyloffset, esym); 1943284Srgrimes * [return address == 0, and can NOT be returned to] 1953284Srgrimes * [cyloffset was not supported by the FreeBSD boot code 1963284Srgrimes * and always passed in as 0] 1973284Srgrimes * [esym is also known as total in the boot code, and 1983284Srgrimes * was never properly supported by the FreeBSD boot code] 1993284Srgrimes * 2003284Srgrimes * Old diskless netboot code: 2013284Srgrimes * (*btext)(0,0,0,0,&nfsdiskless,0,0,0); 2023284Srgrimes * [return address != 0, and can NOT be returned to] 2033284Srgrimes * If we are being booted by this code it will NOT work, 2043284Srgrimes * so we are just going to halt if we find this case. 2053284Srgrimes * 2063284Srgrimes * New uniform boot code: 2073284Srgrimes * (*btext)(howto, bootdev, 0, 0, 0, &bootinfo) 2083284Srgrimes * [return address != 0, and can be returned to] 2093284Srgrimes * 2103284Srgrimes * There may seem to be a lot of wasted arguments in here, but 2113384Srgrimes * that is so the newer boot code can still load very old kernels 2123384Srgrimes * and old boot code can load new kernels. 2134Srgrimes */ 2143284Srgrimes 2153284Srgrimes /* 2163284Srgrimes * The old style disk boot blocks fake a frame on the stack and 2173284Srgrimes * did an lret to get here. The frame on the stack has a return 2183284Srgrimes * address of 0. 2193284Srgrimes */ 2203384Srgrimes cmpl $0,4(%ebp) 2213284Srgrimes je 2f /* olddiskboot: */ 2223284Srgrimes 2233284Srgrimes /* 2243284Srgrimes * We have some form of return address, so this is either the 2253284Srgrimes * old diskless netboot code, or the new uniform code. That can 2263284Srgrimes * be detected by looking at the 5th argument, it if is 0 we 2273284Srgrimes * we are being booted by the new unifrom boot code. 2283284Srgrimes */ 2293384Srgrimes cmpl $0,24(%ebp) 2303284Srgrimes je 1f /* newboot: */ 2313284Srgrimes 2323284Srgrimes /* 2333284Srgrimes * Seems we have been loaded by the old diskless boot code, we 2343284Srgrimes * don't stand a chance of running as the diskless structure 2353284Srgrimes * changed considerably between the two, so just halt. 2363284Srgrimes */ 2373284Srgrimes hlt 2383284Srgrimes 2393284Srgrimes /* 2403384Srgrimes * We have been loaded by the new uniform boot code. 2413384Srgrimes * Lets check the bootinfo version, and if we do not understand 2423384Srgrimes * it we return to the loader with a status of 1 to indicate this error 2433284Srgrimes */ 2443284Srgrimes1: /* newboot: */ 2453384Srgrimes movl 28(%ebp),%ebx /* &bootinfo.version */ 2463384Srgrimes movl BOOTINFO_VERSION(%ebx),%eax 2473384Srgrimes cmpl $1,%eax /* We only understand version 1 */ 2483384Srgrimes je 1f 2493384Srgrimes movl $1,%eax /* Return status */ 2503384Srgrimes leave 2513384Srgrimes ret 2523284Srgrimes 2533384Srgrimes1: 2543284Srgrimes /* 2553384Srgrimes * If we have a kernelname copy it in 2563384Srgrimes */ 2573384Srgrimes movl BOOTINFO_KERNELNAME(%ebx),%esi 2583384Srgrimes cmpl $0,%esi 2593384Srgrimes je 1f /* No kernelname */ 2603384Srgrimes lea _kernelname-KERNBASE,%edi 2613384Srgrimes movl $MAXPATHLEN,%ecx /* Brute force!!! */ 2623384Srgrimes cld 2633384Srgrimes rep 2643384Srgrimes movsb 2653384Srgrimes 2663384Srgrimes1: 2674600Sphk /* 2684600Sphk * Copy the bootinfo structure 2694600Sphk */ 2704600Sphk movl %ebx,%esi 2714600Sphk lea _bootinfo-KERNBASE,%edi 2724600Sphk movl $BOOTINFO_SIZE,%ecx 2734600Sphk cld 2744600Sphk rep 2754600Sphk movsb 2764600Sphk 2773426Srgrimes#ifdef NFS 2783384Srgrimes /* 2793384Srgrimes * If we have a nfs_diskless structure copy it in 2803384Srgrimes */ 2813384Srgrimes movl BOOTINFO_NFS_DISKLESS(%ebx),%esi 2823384Srgrimes cmpl $0,%esi 2833384Srgrimes je 2f 2843384Srgrimes lea _nfs_diskless-KERNBASE,%edi 2853384Srgrimes movl $NFSDISKLESS_SIZE,%ecx 2863384Srgrimes cld 2873384Srgrimes rep 2883384Srgrimes movsb 2893795Sphk lea _nfs_diskless_valid-KERNBASE,%edi 2903795Sphk movl $1,(%edi) 2913406Sdg#endif 2923384Srgrimes 2933384Srgrimes /* 2943284Srgrimes * The old style disk boot. 2953284Srgrimes * (*btext)(howto, bootdev, cyloffset, esym); 2963384Srgrimes * Note that the newer boot code just falls into here to pick 2973384Srgrimes * up howto and bootdev, cyloffset and esym are no longer used 2983284Srgrimes */ 2993284Srgrimes2: /* olddiskboot: */ 3003384Srgrimes movl 8(%ebp),%eax 301570Srgrimes movl %eax,_boothowto-KERNBASE 3023384Srgrimes movl 12(%ebp),%eax 303570Srgrimes movl %eax,_bootdev-KERNBASE 3042783Ssos 3053489Sphk#if NAPM > 0 3063258Sdg /* 3073258Sdg * Setup APM BIOS: 3083258Sdg * 3093258Sdg * APM BIOS initialization should be done from real mode or V86 mode. 3103258Sdg * 3113258Sdg * (by HOSOKAWA, Tatsumi <hosokawa@mt.cs.keio.ac.jp>) 3123258Sdg */ 3134Srgrimes 3143258Sdg /* 3153258Sdg * Copy APM initializer under 1MB boundary: 3163258Sdg * 3173258Sdg * APM initializer program must switch the CPU to real mode. 3183258Sdg * But FreeBSD kernel runs above 1MB boundary. So we must 3193258Sdg * copy the initializer code to conventional memory. 3203258Sdg */ 3213258Sdg movl _apm_init_image_size-KERNBASE, %ecx /* size */ 3223258Sdg lea _apm_init_image-KERNBASE, %esi /* source */ 3233258Sdg movl $ APM_OURADDR, %edi /* destination */ 3243258Sdg cld 3253258Sdg rep 3263258Sdg movsb 3273258Sdg 3283258Sdg /* get GDT base */ 3293258Sdg sgdt _apm_current_gdt_pdesc-KERNBASE 3303258Sdg 3313258Sdg /* copy GDT to _bootstrap_gdt */ 3323258Sdg xorl %ecx, %ecx 3333258Sdg movw _apm_current_gdt_pdesc-KERNBASE, %cx 3343258Sdg movl _apm_current_gdt_pdesc-KERNBASE+2, %esi 3353258Sdg lea _bootstrap_gdt-KERNBASE, %edi 3363258Sdg cld 3373258Sdg rep 3383258Sdg movsb 3393258Sdg 3403258Sdg /* setup GDT pseudo descriptor */ 3413258Sdg movw $(SIZEOF_GDT*BOOTSTRAP_GDT_NUM), %ax 3423258Sdg movw %ax, _apm_current_gdt_pdesc-KERNBASE 3433258Sdg leal _bootstrap_gdt-KERNBASE, %eax 3443258Sdg movl %eax, _apm_current_gdt_pdesc-KERNBASE+2 3453258Sdg 3463258Sdg /* load new GDTR */ 3473258Sdg lgdt _apm_current_gdt_pdesc-KERNBASE 3483258Sdg 3493258Sdg /* setup GDT for APM initializer */ 3503258Sdg lea _bootstrap_gdt-KERNBASE, %ecx 3513258Sdg movl $(APM_OURADDR), %eax /* use %ax for 15..0 */ 3523258Sdg movl %eax, %ebx 3533258Sdg shrl $16, %ebx /* use %bl for 23..16 */ 3543258Sdg /* use %bh for 31..24 */ 3553258Sdg#define APM_SETUP_GDT(index, attrib) \ 3563258Sdg movl $(index), %si ; \ 3573258Sdg lea 0(%ecx,%esi,8), %edx ; \ 3583258Sdg movw $0xffff, (%edx) ; \ 3593258Sdg movw %ax, 2(%edx) ; \ 3603258Sdg movb %bl, 4(%edx) ; \ 3613258Sdg movw $(attrib), 5(%edx) ; \ 3623258Sdg movb %bh, 7(%edx) 3633258Sdg 3643258Sdg APM_SETUP_GDT(APM_INIT_CS_INDEX , CS32_ATTRIB) 3653258Sdg APM_SETUP_GDT(APM_INIT_DS_INDEX , DS32_ATTRIB) 3663258Sdg APM_SETUP_GDT(APM_INIT_CS16_INDEX, CS16_ATTRIB) 3673258Sdg 3683258Sdg /* 3693258Sdg * Call the initializer: 3703258Sdg * 3713258Sdg * direct intersegment call to conventional memory code 3723258Sdg */ 3733258Sdg .byte 0x9a /* actually, lcall $APM_INIT_CS_SEL, $0 */ 3743258Sdg .long 0 3753258Sdg .word APM_INIT_CS_SEL 3763258Sdg 3773258Sdg movw %ax, _apm_version-KERNBASE 3783258Sdg movl %ebx, _apm_cs_entry-KERNBASE 3793258Sdg movw %cx, _apm_cs32_base-KERNBASE 3803258Sdg shrl $16, %ecx 3813258Sdg movw %cx, _apm_cs16_base-KERNBASE 3823258Sdg movw %dx, _apm_ds_base-KERNBASE 3833258Sdg movw %si, _apm_cs_limit-KERNBASE 3843258Sdg shrl $16, %esi 3853258Sdg movw %si, _apm_ds_limit-KERNBASE 3863258Sdg movw %di, _apm_flags-KERNBASE 3873489Sphk#endif /* NAPM */ 3883258Sdg 3891998Swollman /* Find out our CPU type. */ 3901321Sdg 3911998Swollman /* Try to toggle alignment check flag; does not exist on 386. */ 3921998Swollman pushfl 3931998Swollman popl %eax 3941998Swollman movl %eax,%ecx 3951998Swollman orl $PSL_AC,%eax 3961998Swollman pushl %eax 3971998Swollman popfl 3981998Swollman pushfl 3991998Swollman popl %eax 4001998Swollman xorl %ecx,%eax 4011998Swollman andl $PSL_AC,%eax 4021998Swollman pushl %ecx 4031998Swollman popfl 4041998Swollman 4051998Swollman testl %eax,%eax 4061998Swollman jnz 1f 4071998Swollman movl $CPU_386,_cpu-KERNBASE 408556Srgrimes jmp 2f 4091998Swollman 4101998Swollman1: /* Try to toggle identification flag; does not exist on early 486s. */ 4111998Swollman pushfl 4121998Swollman popl %eax 4131998Swollman movl %eax,%ecx 4141998Swollman xorl $PSL_ID,%eax 4151998Swollman pushl %eax 4161998Swollman popfl 4171998Swollman pushfl 4181998Swollman popl %eax 4191998Swollman xorl %ecx,%eax 4201998Swollman andl $PSL_ID,%eax 4211998Swollman pushl %ecx 4221998Swollman popfl 4231998Swollman 4241998Swollman testl %eax,%eax 4251998Swollman jnz 1f 4261998Swollman movl $CPU_486,_cpu-KERNBASE 4272495Spst 4282495Spst /* check for Cyrix 486DLC -- based on check routine */ 4292495Spst /* documented in "Cx486SLC/e SMM Programmer's Guide" */ 4302495Spst xorw %dx,%dx 4312495Spst cmpw %dx,%dx # set flags to known state 4322495Spst pushfw 4332495Spst popw %cx # store flags in ecx 4342495Spst movw $0xffff,%ax 4352495Spst movw $0x0004,%bx 4362495Spst divw %bx 4372495Spst pushfw 4382495Spst popw %ax 4392495Spst andw $0x08d5,%ax # mask off important bits 4402495Spst andw $0x08d5,%cx 4412495Spst cmpw %ax,%cx 4422495Spst 4432495Spst jnz 2f # if flags changed, Intel chip 4442495Spst 4452495Spst movl $CPU_486DLC,_cpu-KERNBASE # set CPU value for Cyrix 4462495Spst movl $0x69727943,_cpu_vendor-KERNBASE # store vendor string 4472495Spst movw $0x0078,_cpu_vendor-KERNBASE+4 4482495Spst 4492495Spst invd # Start with guaranteed clean cache 4502495Spst /* Disable caching of the ISA hole only. */ 4512495Spst movb $CCR0,%al # Configuration Register index (CCR0) 4522495Spst outb %al,$0x22 4532495Spst inb $0x23,%al 4543117Spst orb $(CCR0_NC1|CCR0_BARB),%al 4552495Spst outb %al,$0x23 4562495Spst invd 4571998Swollman jmp 2f 4581998Swollman 4591998Swollman1: /* Use the `cpuid' instruction. */ 4601998Swollman xorl %eax,%eax 4611998Swollman .byte 0x0f,0xa2 # cpuid 0 4621998Swollman movl %ebx,_cpu_vendor-KERNBASE # store vendor string 4631998Swollman movl %edx,_cpu_vendor+4-KERNBASE 4641998Swollman movl %ecx,_cpu_vendor+8-KERNBASE 4651998Swollman movb $0,_cpu_vendor+12-KERNBASE 4661998Swollman 4671998Swollman movl $1,%eax 4681998Swollman .byte 0x0f,0xa2 # cpuid 1 4691998Swollman movl %eax,_cpu_id-KERNBASE # store cpu_id 4701998Swollman rorl $8,%eax # extract family type 4711998Swollman andl $15,%eax 4721998Swollman cmpl $5,%eax 4731998Swollman jae 1f 4741998Swollman 4751998Swollman /* less than Pentium; must be 486 */ 4761998Swollman movl $CPU_486,_cpu-KERNBASE 4771998Swollman jmp 2f 4781998Swollman 4791998Swollman1: movl $CPU_586,_cpu-KERNBASE 480556Srgrimes2: 481556Srgrimes 4824Srgrimes /* 4834Srgrimes * Finished with old stack; load new %esp now instead of later so 4844Srgrimes * we can trace this code without having to worry about the trace 4854Srgrimes * trap clobbering the memory test or the zeroing of the bss+bootstrap 4864Srgrimes * page tables. 4874Srgrimes * 4884Srgrimes * XXX - wdboot clears the bss after testing that this is safe. 4894Srgrimes * This is too wasteful - memory below 640K is scarce. The boot 4904Srgrimes * program should check: 4914Srgrimes * text+data <= &stack_variable - more_space_for_stack 4924Srgrimes * text+data+bss+pad+space_for_page_tables <= end_of_memory 4934Srgrimes * Oops, the gdt is in the carcass of the boot program so clearing 4944Srgrimes * the rest of memory is still not possible. 4954Srgrimes */ 496757Sdg movl $tmpstk-KERNBASE,%esp /* bootstrap stack end location */ 4974Srgrimes 498570Srgrimes/* 499570Srgrimes * Virtual address space of kernel: 500570Srgrimes * 501570Srgrimes * text | data | bss | [syms] | page dir | proc0 kernel stack | usr stk map | Sysmap 502974Sdg * pages: 1 UPAGES (2) 1 NKPT (7) 503570Srgrimes */ 504570Srgrimes 5054Srgrimes/* find end of kernel image */ 506570Srgrimes movl $_end-KERNBASE,%ecx 507757Sdg addl $NBPG-1,%ecx /* page align up */ 5084Srgrimes andl $~(NBPG-1),%ecx 5091321Sdg movl %ecx,%esi /* esi = start of free memory */ 510757Sdg movl %ecx,_KERNend-KERNBASE /* save end of kernel */ 5114Srgrimes 512757Sdg/* clear bss */ 513570Srgrimes movl $_edata-KERNBASE,%edi 514760Srgrimes subl %edi,%ecx /* get amount to clear */ 515757Sdg xorl %eax,%eax /* specify zero fill */ 5164Srgrimes cld 5174Srgrimes rep 5184Srgrimes stosb 5194Srgrimes 520608Srgrimes/* 521974Sdg * The value in esi is both the end of the kernel bss and a pointer to 522974Sdg * the kernel page directory, and is used by the rest of locore to build 523974Sdg * the tables. 524974Sdg * esi + 1(page dir) + 2(UPAGES) + 1(p0stack) + NKPT(number of kernel 525757Sdg * page table pages) is then passed on the stack to init386(first) as 526757Sdg * the value first. esi should ALWAYS be page aligned!! 527608Srgrimes */ 528757Sdg movl %esi,%ecx /* Get current first availiable address */ 529608Srgrimes 530757Sdg/* clear pagetables, page directory, stack, etc... */ 531757Sdg movl %esi,%edi /* base (page directory) */ 532974Sdg movl $((1+UPAGES+1+NKPT)*NBPG),%ecx /* amount to clear */ 533757Sdg xorl %eax,%eax /* specify zero fill */ 534757Sdg cld 535757Sdg rep 536757Sdg stosb 537757Sdg 538757Sdg/* physical address of Idle proc/kernel page directory */ 539570Srgrimes movl %esi,_IdlePTD-KERNBASE 5404Srgrimes 541592Srgrimes/* 542592Srgrimes * fillkpt 543592Srgrimes * eax = (page frame address | control | status) == pte 544592Srgrimes * ebx = address of page table 545592Srgrimes * ecx = how many pages to map 546592Srgrimes */ 5474Srgrimes#define fillkpt \ 5484Srgrimes1: movl %eax,(%ebx) ; \ 549570Srgrimes addl $NBPG,%eax ; /* increment physical address */ \ 5504Srgrimes addl $4,%ebx ; /* next pte */ \ 5514Srgrimes loop 1b ; 5524Srgrimes 5534Srgrimes/* 5544Srgrimes * Map Kernel 5554Srgrimes * 5564Srgrimes * First step - build page tables 5574Srgrimes */ 558757Sdg#if defined (KGDB) || defined (BDE_DEBUGGER) 559757Sdg movl _KERNend-KERNBASE,%ecx /* this much memory, */ 560757Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 561757Sdg#ifdef BDE_DEBUGGER 562757Sdg cmpl $0xa0,%ecx /* XXX - cover debugger pages */ 563200Sdg jae 1f 564200Sdg movl $0xa0,%ecx 565200Sdg1: 566757Sdg#endif /* BDE_DEBUGGER */ 5672512Sbde movl $PG_V|PG_KW,%eax /* kernel R/W, valid */ 568757Sdg lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 569757Sdg movl %ebx,_KPTphys-KERNBASE /* save in global */ 5704Srgrimes fillkpt 5714Srgrimes 572757Sdg#else /* !KGDB && !BDE_DEBUGGER */ 573757Sdg /* write protect kernel text (doesn't do a thing for 386's - only 486's) */ 574757Sdg movl $_etext-KERNBASE,%ecx /* get size of text */ 5753842Sdg addl $NBPG-1,%ecx /* round up to page */ 576757Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 577757Sdg movl $PG_V|PG_KR,%eax /* specify read only */ 5783842Sdg#if 0 5793842Sdg movl $_etext,%ecx /* get size of text */ 5803842Sdg subl $_btext,%ecx 5813842Sdg addl $NBPG-1,%ecx /* round up to page */ 5823842Sdg shrl $PGSHIFT,%ecx /* for this many PTEs */ 5833842Sdg movl $_btext-KERNBASE,%eax /* get offset to physical memory */ 5843842Sdg orl $PG_V|PG_KR,%eax /* specify read only */ 5853842Sdg#endif 586757Sdg lea ((1+UPAGES+1)*NBPG)(%esi),%ebx /* phys addr of kernel PT base */ 587757Sdg movl %ebx,_KPTphys-KERNBASE /* save in global */ 588757Sdg fillkpt 589757Sdg 590757Sdg /* data and bss are r/w */ 591757Sdg andl $PG_FRAME,%eax /* strip to just addr of bss */ 592757Sdg movl _KERNend-KERNBASE,%ecx /* calculate size */ 593757Sdg subl %eax,%ecx 594757Sdg shrl $PGSHIFT,%ecx 595757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 596757Sdg fillkpt 5971321Sdg#endif /* KGDB || BDE_DEBUGGER */ 598757Sdg 599757Sdg/* now initialize the page dir, upages, p0stack PT, and page tables */ 600757Sdg 601974Sdg movl $(1+UPAGES+1+NKPT),%ecx /* number of PTEs */ 602757Sdg movl %esi,%eax /* phys address of PTD */ 603757Sdg andl $PG_FRAME,%eax /* convert to PFN, should be a NOP */ 6042512Sbde orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 605757Sdg movl %esi,%ebx /* calculate pte offset to ptd */ 606757Sdg shrl $PGSHIFT-2,%ebx 607757Sdg addl %esi,%ebx /* address of page directory */ 608757Sdg addl $((1+UPAGES+1)*NBPG),%ebx /* offset to kernel page tables */ 609757Sdg fillkpt 6101321Sdg 6114Srgrimes/* map I/O memory map */ 6124Srgrimes 613757Sdg movl _KPTphys-KERNBASE,%ebx /* base of kernel page tables */ 614757Sdg lea (0xa0 * PTESIZE)(%ebx),%ebx /* hardwire ISA hole at KERNBASE + 0xa0000 */ 615757Sdg movl $0x100-0xa0,%ecx /* for this many pte s, */ 6161046Sdg movl $(0xa0000|PG_V|PG_KW|PG_N),%eax /* valid, kernel read/write, non-cacheable */ 617757Sdg movl %ebx,_atdevphys-KERNBASE /* save phys addr of ptes */ 6184Srgrimes fillkpt 6194Srgrimes 6204Srgrimes /* map proc 0's kernel stack into user page table page */ 6214Srgrimes 622757Sdg movl $UPAGES,%ecx /* for this many pte s, */ 623757Sdg lea (1*NBPG)(%esi),%eax /* physical address in proc 0 */ 624757Sdg lea (KERNBASE)(%eax),%edx /* change into virtual addr */ 625757Sdg movl %edx,_proc0paddr-KERNBASE /* save VA for proc 0 init */ 626757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 627757Sdg lea ((1+UPAGES)*NBPG)(%esi),%ebx /* addr of stack page table in proc 0 */ 628757Sdg addl $(KSTKPTEOFF * PTESIZE),%ebx /* offset to kernel stack PTE */ 6294Srgrimes fillkpt 6304Srgrimes 6314Srgrimes/* 632757Sdg * Initialize kernel page table directory 6334Srgrimes */ 6344Srgrimes /* install a pde for temporary double map of bottom of VA */ 635757Sdg movl _KPTphys-KERNBASE,%eax 636757Sdg orl $PG_V|PG_KW,%eax /* valid, kernel read/write */ 637757Sdg movl %eax,(%esi) /* which is where temp maps! */ 6384Srgrimes 639757Sdg /* initialize kernel pde's */ 640974Sdg movl $(NKPT),%ecx /* for this many PDEs */ 641757Sdg lea (KPTDI*PDESIZE)(%esi),%ebx /* offset of pde for kernel */ 6424Srgrimes fillkpt 6434Srgrimes 6444Srgrimes /* install a pde recursively mapping page directory as a page table! */ 645757Sdg movl %esi,%eax /* phys address of ptd in proc 0 */ 646757Sdg orl $PG_V|PG_KW,%eax /* pde entry is valid */ 647757Sdg movl %eax,PTDPTDI*PDESIZE(%esi) /* which is where PTmap maps! */ 6484Srgrimes 6494Srgrimes /* install a pde to map kernel stack for proc 0 */ 650757Sdg lea ((1+UPAGES)*NBPG)(%esi),%eax /* physical address of pt in proc 0 */ 651757Sdg orl $PG_V|PG_KW,%eax /* pde entry is valid */ 652757Sdg movl %eax,KSTKPTDI*PDESIZE(%esi) /* which is where kernel stack maps! */ 6534Srgrimes 654757Sdg#ifdef BDE_DEBUGGER 6554Srgrimes /* copy and convert stuff from old gdt and idt for debugger */ 6564Srgrimes 657757Sdg cmpl $0x0375c339,0x96104 /* XXX - debugger signature */ 6584Srgrimes jne 1f 659570Srgrimes movb $1,_bdb_exists-KERNBASE 6604Srgrimes1: 6614Srgrimes pushal 6624Srgrimes subl $2*6,%esp 6634Srgrimes 6644Srgrimes sgdt (%esp) 665757Sdg movl 2(%esp),%esi /* base address of current gdt */ 666570Srgrimes movl $_gdt-KERNBASE,%edi 6674Srgrimes movl %edi,2(%esp) 6684Srgrimes movl $8*18/4,%ecx 6691688Sdg cld 670757Sdg rep /* copy gdt */ 6714Srgrimes movsl 672570Srgrimes movl $_gdt-KERNBASE,-8+2(%edi) /* adjust gdt self-ptr */ 6734Srgrimes movb $0x92,-8+5(%edi) 6744Srgrimes 6754Srgrimes sidt 6(%esp) 676757Sdg movl 6+2(%esp),%esi /* base address of current idt */ 677757Sdg movl 8+4(%esi),%eax /* convert dbg descriptor to ... */ 6784Srgrimes movw 8(%esi),%ax 679570Srgrimes movl %eax,bdb_dbg_ljmp+1-KERNBASE /* ... immediate offset ... */ 6804Srgrimes movl 8+2(%esi),%eax 681570Srgrimes movw %ax,bdb_dbg_ljmp+5-KERNBASE /* ... and selector for ljmp */ 682757Sdg movl 24+4(%esi),%eax /* same for bpt descriptor */ 6834Srgrimes movw 24(%esi),%ax 684570Srgrimes movl %eax,bdb_bpt_ljmp+1-KERNBASE 6854Srgrimes movl 24+2(%esi),%eax 686570Srgrimes movw %ax,bdb_bpt_ljmp+5-KERNBASE 6874Srgrimes 688570Srgrimes movl $_idt-KERNBASE,%edi 6894Srgrimes movl %edi,6+2(%esp) 6904Srgrimes movl $8*4/4,%ecx 6911688Sdg cld 692757Sdg rep /* copy idt */ 6934Srgrimes movsl 6944Srgrimes 6954Srgrimes lgdt (%esp) 6964Srgrimes lidt 6(%esp) 6974Srgrimes 6984Srgrimes addl $2*6,%esp 6994Srgrimes popal 7001321Sdg#endif /* BDE_DEBUGGER */ 7014Srgrimes 702592Srgrimes /* load base of page directory and enable mapping */ 703757Sdg movl %esi,%eax /* phys address of ptd in proc 0 */ 704757Sdg movl %eax,%cr3 /* load ptd addr into mmu */ 705757Sdg movl %cr0,%eax /* get control word */ 706757Sdg orl $CR0_PE|CR0_PG,%eax /* enable paging */ 707757Sdg movl %eax,%cr0 /* and let's page NOW! */ 7084Srgrimes 709757Sdg pushl $begin /* jump to high mem */ 7104Srgrimes ret 7114Srgrimes 712570Srgrimesbegin: /* now running relocated at KERNBASE where the system is linked to run */ 713757Sdg movl _atdevphys,%edx /* get pte PA */ 714757Sdg subl _KPTphys,%edx /* remove base of ptes, now have phys offset */ 715757Sdg shll $PGSHIFT-2,%edx /* corresponding to virt offset */ 716757Sdg addl $KERNBASE,%edx /* add virtual base */ 717570Srgrimes movl %edx,_atdevbase 7183728Sphk 7193861Sbde#include "sc.h" 7204031Sjoerg#include "vt.h" 7214031Sjoerg#if NSC > 0 || NVT > 0 7223728Sphk /* XXX: can't scinit relocate Crtat relative to atdevbase itself? */ 7233728Sphk .globl _Crtat /* XXX - locore should not know about */ 7243728Sphk movl _Crtat,%eax /* variables of device drivers (pccons)! */ 7253728Sphk subl $(KERNBASE+0xA0000),%eax 7264Srgrimes addl %eax,%edx 7274Srgrimes movl %edx,_Crtat 7283728Sphk#endif 7294Srgrimes 730757Sdg /* set up bootstrap stack - 48 bytes */ 731570Srgrimes movl $_kstack+UPAGES*NBPG-4*12,%esp /* bootstrap stack end location */ 732757Sdg xorl %eax,%eax /* mark end of frames */ 7334Srgrimes movl %eax,%ebp 734570Srgrimes movl _proc0paddr,%eax 735570Srgrimes movl %esi,PCB_CR3(%eax) 7364Srgrimes 737757Sdg#ifdef BDE_DEBUGGER 7384Srgrimes /* relocate debugger gdt entries */ 7394Srgrimes 740757Sdg movl $_gdt+8*9,%eax /* adjust slots 9-17 */ 7414Srgrimes movl $9,%ecx 7424Srgrimesreloc_gdt: 7431321Sdg movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */ 744757Sdg addl $8,%eax /* now KERNBASE>>24 */ 7454Srgrimes loop reloc_gdt 7464Srgrimes 7474Srgrimes cmpl $0,_bdb_exists 7484Srgrimes je 1f 7494Srgrimes int $3 7504Srgrimes1: 7511321Sdg#endif /* BDE_DEBUGGER */ 7524Srgrimes 753608Srgrimes /* 754608Srgrimes * Skip over the page tables and the kernel stack 755608Srgrimes */ 756974Sdg lea ((1+UPAGES+1+NKPT)*NBPG)(%esi),%esi 757608Srgrimes 758757Sdg pushl %esi /* value of first for init386(first) */ 759757Sdg call _init386 /* wire 386 chip for unix operation */ 7601549Srgrimes popl %esi 761200Sdg 7621549Srgrimes .globl __ucodesel,__udatasel 7631549Srgrimes 7641549Srgrimes pushl $0 /* unused */ 7651549Srgrimes pushl __udatasel /* ss */ 7661549Srgrimes pushl $0 /* esp - filled in by execve() */ 7672500Sdg pushl $PSL_USERSET /* eflags (ring 0, int enab) */ 7681549Srgrimes pushl __ucodesel /* cs */ 7691549Srgrimes pushl $0 /* eip - filled in by execve() */ 7701549Srgrimes subl $(12*4),%esp /* space for rest of registers */ 7711549Srgrimes 7721549Srgrimes pushl %esp /* call main with frame pointer */ 773757Sdg call _main /* autoconfiguration, mountroot etc */ 7744Srgrimes 7751549Srgrimes addl $(13*4),%esp /* back to a frame we can return with */ 7761549Srgrimes 777134Sdg /* 778570Srgrimes * now we've run main() and determined what cpu-type we are, we can 779570Srgrimes * enable WP mode on i486 cpus and above. 7801058Sdg */ 7811058Sdg#if defined(I486_CPU) || defined(I586_CPU) 7821058Sdg cmpl $CPUCLASS_386,_cpu_class 7831058Sdg je 1f 7841058Sdg movl %cr0,%eax /* get control word */ 7851058Sdg orl $CR0_WP,%eax /* enable write protect for all modes */ 7861058Sdg movl %eax,%cr0 /* and do it */ 7871058Sdg#endif 7881058Sdg /* 789134Sdg * on return from main(), we are process 1 790134Sdg * set up address space and stack so that we can 'return' to user mode 791134Sdg */ 7921058Sdg1: 7934Srgrimes movl __ucodesel,%eax 7944Srgrimes movl __udatasel,%ecx 7951549Srgrimes 7964Srgrimes movl %cx,%ds 7974Srgrimes movl %cx,%es 798757Sdg movl %ax,%fs /* double map cs to fs */ 799757Sdg movl %cx,%gs /* and ds to gs */ 8001549Srgrimes iret /* goto user! */ 8014Srgrimes 8021549Srgrimes#define LCALL(x,y) .byte 0x9a ; .long y ; .word x 8034Srgrimes 804200SdgNON_GPROF_ENTRY(sigcode) 805592Srgrimes call SIGF_HANDLER(%esp) 806757Sdg lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */ 807757Sdg /* copy at 8(%esp)) */ 8084Srgrimes pushl %eax 809757Sdg pushl %eax /* junk to fake return address */ 810757Sdg movl $103,%eax /* XXX sigreturn() */ 811757Sdg LCALL(0x7,0) /* enter kernel with args on stack */ 812757Sdg hlt /* never gets here */ 8134Srgrimes 8144Srgrimes .globl _szsigcode 8154Srgrimes_szsigcode: 8164Srgrimes .long _szsigcode-_sigcode 817