freebsd-nq/sys/pc98/i386/locore.s

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/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)locore.s 7.3 (Berkeley) 5/13/91
* $Id$
*
* originally from: locore.s, by William F. Jolitz
*
* Substantially rewritten by David Greenman, Rod Grimes,
* Bruce Evans, Wolfgang Solfrank, Poul-Henning Kamp
* and many others.
*/
#include "apm.h"
1996-10-09 19:47:44 +00:00
#include "opt_cpu.h"
#include "opt_ddb.h"
#include "opt_userconfig.h"
#include <sys/errno.h>
#include <sys/syscall.h>
#include <sys/reboot.h>
#include <machine/asmacros.h>
#include <machine/cputypes.h>
#include <machine/psl.h>
#include <machine/pmap.h>
#include <machine/specialreg.h>
#include "assym.s"
/*
* XXX
*
* Note: This version greatly munged to avoid various assembler errors
* that may be fixed in newer versions of gas. Perhaps newer versions
* will have more pleasant appearance.
*/
/*
* PTmap is recursive pagemap at top of virtual address space.
* Within PTmap, the page directory can be found (third indirection).
*/
.globl _PTmap,_PTD,_PTDpde
.set _PTmap,(PTDPTDI << PDRSHIFT)
.set _PTD,_PTmap + (PTDPTDI * PAGE_SIZE)
.set _PTDpde,_PTD + (PTDPTDI * PDESIZE)
/*
* APTmap, APTD is the alternate recursive pagemap.
* It's used when modifying another process's page tables.
*/
.globl _APTmap,_APTD,_APTDpde
.set _APTmap,APTDPTDI << PDRSHIFT
.set _APTD,_APTmap + (APTDPTDI * PAGE_SIZE)
.set _APTDpde,_PTD + (APTDPTDI * PDESIZE)
/*
* Access to each processes kernel stack is via a region of
* per-process address space (at the beginning), immediately above
* the user process stack.
*/
.set _kstack,USRSTACK
.globl _kstack
/*
* Globals
*/
.data
ALIGN_DATA /* just to be sure */
.globl tmpstk
.space 0x2000 /* space for tmpstk - temporary stack */
tmpstk:
.globl _boothowto,_bootdev
.globl _cpu,_cpu_vendor,_cpu_id,_bootinfo
.globl _cpu_high, _cpu_feature
_cpu: .long 0 /* are we 386, 386sx, or 486 */
_cpu_id: .long 0 /* stepping ID */
_cpu_high: .long 0 /* highest arg to CPUID */
_cpu_feature: .long 0 /* features */
_cpu_vendor: .space 20 /* CPU origin code */
_bootinfo: .space BOOTINFO_SIZE /* bootinfo that we can handle */
_KERNend: .long 0 /* phys addr end of kernel (just after bss) */
physfree: .long 0 /* phys addr of next free page */
p0upa: .long 0 /* phys addr of proc0's UPAGES */
p0upt: .long 0 /* phys addr of proc0's UPAGES page table */
.globl _IdlePTD
_IdlePTD: .long 0 /* phys addr of kernel PTD */
_KPTphys: .long 0 /* phys addr of kernel page tables */
.globl _proc0paddr
_proc0paddr: .long 0 /* address of proc 0 address space */
#ifdef BDE_DEBUGGER
.globl _bdb_exists /* flag to indicate BDE debugger is present */
_bdb_exists: .long 0
#endif
/**********************************************************************
*
* Some handy macros
*
*/
#define R(foo) ((foo)-KERNBASE)
#define ALLOCPAGES(foo) \
movl R(physfree), %esi ; \
movl $((foo)*PAGE_SIZE), %eax ; \
addl %esi, %eax ; \
movl %eax, R(physfree) ; \
movl %esi, %edi ; \
movl $((foo)*PAGE_SIZE),%ecx ; \
xorl %eax,%eax ; \
cld ; \
rep ; \
stosb
/*
* fillkpt
* eax = page frame address
* ebx = index into page table
* ecx = how many pages to map
* base = base address of page dir/table
* prot = protection bits
*/
#define fillkpt(base, prot) \
shll $2,%ebx ; \
addl base,%ebx ; \
orl $PG_V,%eax ; \
orl prot,%eax ; \
1: movl %eax,(%ebx) ; \
addl $PAGE_SIZE,%eax ; /* increment physical address */ \
addl $4,%ebx ; /* next pte */ \
loop 1b
/*
* fillkptphys(prot)
* eax = physical address
* ecx = how many pages to map
* prot = protection bits
*/
#define fillkptphys(prot) \
movl %eax, %ebx ; \
shrl $PAGE_SHIFT, %ebx ; \
fillkpt(R(_KPTphys), prot)
.text
/**********************************************************************
*
* This is where the bootblocks start us, set the ball rolling...
*
*/
NON_GPROF_ENTRY(btext)
#ifdef PC98
jmp 1f
.globl _pc98_system_parameter
.org 0x400
_pc98_system_parameter:
.space 0x240 /* skip over warm boot shit */
1:
/* save SYSTEM PARAMETER for resume (NS/T or other) */
movl $0xa1000,%esi
movl $0x100000,%edi
movl $0x0630,%ecx
cld
rep
movsb
#else /* IBM-PC */
#ifdef BDE_DEBUGGER
#ifdef BIOS_STEALS_3K
cmpl $0x0375c339,0x95504
#else
cmpl $0x0375c339,0x96104 /* XXX - debugger signature */
#endif
jne 1f
movb $1,R(_bdb_exists)
1:
#endif
/* Tell the bios to warmboot next time */
movw $0x1234,0x472
#endif /* PC98 */
/* Set up a real frame in case the double return in newboot is executed. */
pushl %ebp
movl %esp, %ebp
/* Don't trust what the BIOS gives for eflags. */
pushl $PSL_KERNEL
popfl
/*
* Don't trust what the BIOS gives for %fs and %gs. Trust the bootstrap
* to set %cs, %ds, %es and %ss.
*/
mov %ds, %ax
mov %ax, %fs
mov %ax, %gs
call recover_bootinfo
/* Get onto a stack that we can trust. */
/*
* XXX this step is delayed in case recover_bootinfo needs to return via
* the old stack, but it need not be, since recover_bootinfo actually
* returns via the old frame.
*/
movl $R(tmpstk),%esp
#ifdef PC98
testb $0x02,0x100620 /* pc98_machine_type & M_EPSON_PC98 */
jz 3f
cmpb $0x0b,0x100624 /* epson_machine_id <= 0x0b */
ja 3f
/* count up memory */
movl $0x100000,%eax /* next, talley remaining memory */
movl $(0xFFF-0x100),%ecx
1: movl 0(%eax),%ebx /* save location to check */
movl $0xa55a5aa5,0(%eax) /* write test pattern */
cmpl $0xa55a5aa5,0(%eax) /* does not check yet for rollover */
jne 2f
movl %ebx,0(%eax) /* restore memory */
addl $ PAGE_SIZE,%eax
loop 1b
2: subl $0x100000,%eax
shrl $17,%eax
movb %al,0x100401
3:
#endif
call identify_cpu
/* clear bss */
/*
* XXX this should be done a little earlier.
*
* XXX we don't check that there is memory for our bss and page tables
* before using it.
*
* XXX the boot program somewhat bogusly clears the bss. We still have
* to do it in case we were unzipped by kzipboot. Then the boot program
* only clears kzipboot's bss.
*
* XXX the gdt and idt are still somewhere in the boot program. We
* depend on the convention that the boot program is below 1MB and we
* are above 1MB to keep the gdt and idt away from the bss and page
* tables. The idt is only used if BDE_DEBUGGER is enabled.
*/
movl $R(_end),%ecx
movl $R(_edata),%edi
subl %edi,%ecx
xorl %eax,%eax
cld
rep
stosb
#if NAPM > 0
/*
* XXX it's not clear that APM can live in the current environonment.
* Only pc-relative addressing works.
*/
call _apm_setup
#endif
call create_pagetables
#ifdef BDE_DEBUGGER
/*
* Adjust as much as possible for paging before enabling paging so that the
* adjustments can be traced.
*/
call bdb_prepare_paging
#endif
/* Now enable paging */
movl R(_IdlePTD), %eax
movl %eax,%cr3 /* load ptd addr into mmu */
movl %cr0,%eax /* get control word */
orl $CR0_PE|CR0_PG,%eax /* enable paging */
movl %eax,%cr0 /* and let's page NOW! */
#ifdef BDE_DEBUGGER
/*
* Complete the adjustments for paging so that we can keep tracing through
* initi386() after the low (physical) addresses for the gdt and idt become
* invalid.
*/
call bdb_commit_paging
#endif
pushl $begin /* jump to high virtualized address */
ret
/* now running relocated at KERNBASE where the system is linked to run */
begin:
/* set up bootstrap stack */
movl $_kstack+UPAGES*PAGE_SIZE,%esp /* bootstrap stack end location */
xorl %eax,%eax /* mark end of frames */
movl %eax,%ebp
movl _proc0paddr,%eax
movl _IdlePTD, %esi
movl %esi,PCB_CR3(%eax)
movl physfree, %esi
pushl %esi /* value of first for init386(first) */
call _init386 /* wire 386 chip for unix operation */
#ifdef PC98
#if defined(CYRIX_486DLC) && defined(I486_CPU)
/* Cyrix 486DLC/SLC/DLC2/SLC2 CPU */
cmpl $CPU_486DLC,_cpu
jne 1f
cli
movl %cr0,%eax
orl $0x40000000,%eax /* disable cache */
mov %eax,%cr0
.byte 0x0f,0x08 /* invd */
movb $0xc0,%al
outb %al,$0x22 /* Cyrix486[SD]LC cache controler index */
movb $0x02,%al /* CCR0 = 0x02 (disable cache 640K-1M) */
outb %al,$0x23 /* window */
movb $0xc6,%al
outb %al,$0x22
movb $0x00,%al
outb %al,$0x23 /* NCR1: enable cache in all area */
movb $0x00,%al
outb %al,$0x22 /* dummy window */
movb $0x00,%al
outb %al,$0x23 /* dummy write */
movl %cr0,%eax
andl $0x9fffffff,%eax /* enable cache !! */
movl %eax,%cr0
sti
1:
#endif
#if defined(IBM_486SLC) && defined(I486_CPU)
/* optimization */
cli
movl %cr0,%eax
orl $0x40000000,%eax # disable cache
mov %eax,%cr0
.byte 0x0f,0x08 # invd
movl $0x00000000,%edx
movl $0x00009c92,%eax # If using Intel-FPU,set "1c92" instead.
movl $0x00001000,%ecx
.byte 0x0f,0x30 # wrmsr
movl $0x000000d0,%edx # 13MB(0x0d) cache.(over1MB-14MB region)
movl $0x000003ff,%eax # 0-640KB cache. (64KB block * 10)
movl $0x00001001,%ecx
.byte 0x0f,0x30 # wrmsr
movl $0x00000000,%edx
movl $0x03000000,%eax # "3" means double-clock-mode. or set all-zero.
movl $0x00001002,%ecx
.byte 0x0f,0x30 # wrmsr
movl %cr0,%eax
andl $0x9fffffff,%eax # enable cache !!
movl %eax,%cr0
sti
#endif
#ifdef CYRIX_5X86
/* CYRIX 5x86 CPU */
cli
outb %al,$0x50 # Reset NMI F/F
mov %cr0,%eax
orl $0x40000000,%eax # disable cache
movl %eax,%cr0
wbinvd # flush buffer
movb $0xc3,%al
outb %al,$0x22
inb $0x23,%al
movb $0x0c1,%al # CCR1
outb %al,$0x22
movb $0x00,%al # No SMM support
outb %al,$0x23
movb $0x0c2,%al # CCR2
outb %al,$0x22
#ifdef SUSP_HLT
movb $0x0a,%al # USE_WBAK, SUSP_HLT
#else
movb $0x02,%al # USE_WBAK
#endif
outb %al,$0x23
movb $0xc3,%al # CCR3
outb %al,$0x22 #
movb $0x10,%al # MAPEN0 (to access CCR4)
outb %al,$0x23
movb $0x0e8,%al # CCR4
outb %al,$0x22
movb $0x18, %al # DTE_EN, MEM_BYP
#ifdef FASTER_5X86_FPU
orb $0x20, %al # UNDOCUMENTED OPTION
#endif
#ifdef CX586_IO
orb $CX586_IO, %al
#endif
outb %al,$0x23
movb $0x020,%al # PCR0
outb %al,$0x22
xorb %al, %al
#ifdef RSTK_EN
orb $0x01, %al # Return Stack Enable
#endif
#ifdef BTB_EN
orb $0x02, %al # Branch Target Buffer enable
#endif
#ifdef LOOP_EN
orb $0x04, %al # Loop Enable
#endif
1997-01-11 08:59:45 +00:00
#ifndef DISABLE_5X86_LSSER
orb $0x80, %al # Reorder
#endif
outb %al,$0x23
movb $0x0c3,%al # CCR3
outb %al,$0x22
movb $0x00,%al
outb %al,$0x23
movb $0x80,%al # dummy
outb %al,$0x22
inb $0x23,%al
movl %cr0,%ebx
andl $0x0bfffffff,%ebx # enable cache
orl $0x020000000,%ebx # write back mode
movl %ebx,%cr0 # go!
outb %al,$0x52 # Set NMI F/F
sti
#endif /* CYRIX_5X86 */
#endif /* PC98 */
popl %esi
.globl __ucodesel,__udatasel
pushl $0 /* unused */
pushl __udatasel /* ss */
pushl $0 /* esp - filled in by execve() */
pushl $PSL_USER /* eflags (IOPL 0, int enab) */
pushl __ucodesel /* cs */
pushl $0 /* eip - filled in by execve() */
subl $(12*4),%esp /* space for rest of registers */
pushl %esp /* call main with frame pointer */
call _main /* autoconfiguration, mountroot etc */
addl $(13*4),%esp /* back to a frame we can return with */
/*
* now we've run main() and determined what cpu-type we are, we can
* enable write protection and alignment checking on i486 cpus and
* above.
*/
#if defined(I486_CPU) || defined(I586_CPU) || defined(I686_CPU)
cmpl $CPUCLASS_386,_cpu_class
je 1f
movl %cr0,%eax /* get control word */
orl $CR0_WP|CR0_AM,%eax /* enable i486 features */
movl %eax,%cr0 /* and do it */
1:
#endif
/*
* on return from main(), we are process 1
* set up address space and stack so that we can 'return' to user mode
*/
movl __ucodesel,%eax
movl __udatasel,%ecx
movl %cx,%ds
movl %cx,%es
movl %ax,%fs /* double map cs to fs */
movl %cx,%gs /* and ds to gs */
iret /* goto user! */
#define LCALL(x,y) .byte 0x9a ; .long y ; .word x
/*
* Signal trampoline, copied to top of user stack
*/
NON_GPROF_ENTRY(sigcode)
call SIGF_HANDLER(%esp)
lea SIGF_SC(%esp),%eax /* scp (the call may have clobbered the */
/* copy at 8(%esp)) */
pushl %eax
pushl %eax /* junk to fake return address */
movl $SYS_sigreturn,%eax /* sigreturn() */
LCALL(0x7,0) /* enter kernel with args on stack */
hlt /* never gets here */
.align 2,0x90 /* long word text-align */
_esigcode:
.data
.globl _szsigcode
_szsigcode:
.long _esigcode-_sigcode
.text
/**********************************************************************
*
* Recover the bootinfo passed to us from the boot program
*
*/
recover_bootinfo:
/*
* This code is called in different ways depending on what loaded
* and started the kernel. This is used to detect how we get the
* arguments from the other code and what we do with them.
*
* Old disk boot blocks:
* (*btext)(howto, bootdev, cyloffset, esym);
* [return address == 0, and can NOT be returned to]
* [cyloffset was not supported by the FreeBSD boot code
* and always passed in as 0]
* [esym is also known as total in the boot code, and
* was never properly supported by the FreeBSD boot code]
*
* Old diskless netboot code:
* (*btext)(0,0,0,0,&nfsdiskless,0,0,0);
* [return address != 0, and can NOT be returned to]
* If we are being booted by this code it will NOT work,
* so we are just going to halt if we find this case.
*
* New uniform boot code:
* (*btext)(howto, bootdev, 0, 0, 0, &bootinfo)
* [return address != 0, and can be returned to]
*
* There may seem to be a lot of wasted arguments in here, but
* that is so the newer boot code can still load very old kernels
* and old boot code can load new kernels.
*/
/*
* The old style disk boot blocks fake a frame on the stack and
* did an lret to get here. The frame on the stack has a return
* address of 0.
*/
cmpl $0,4(%ebp)
je olddiskboot
/*
* We have some form of return address, so this is either the
* old diskless netboot code, or the new uniform code. That can
* be detected by looking at the 5th argument, if it is 0
* we are being booted by the new uniform boot code.
*/
cmpl $0,24(%ebp)
je newboot
/*
* Seems we have been loaded by the old diskless boot code, we
* don't stand a chance of running as the diskless structure
* changed considerably between the two, so just halt.
*/
hlt
/*
* We have been loaded by the new uniform boot code.
* Let's check the bootinfo version, and if we do not understand
* it we return to the loader with a status of 1 to indicate this error
*/
newboot:
movl 28(%ebp),%ebx /* &bootinfo.version */
movl BI_VERSION(%ebx),%eax
cmpl $1,%eax /* We only understand version 1 */
je 1f
movl $1,%eax /* Return status */
leave
/*
* XXX this returns to our caller's caller (as is required) since
* we didn't set up a frame and our caller did.
*/
ret
1:
/*
* If we have a kernelname copy it in
*/
movl BI_KERNELNAME(%ebx),%esi
cmpl $0,%esi
je 2f /* No kernelname */
movl $MAXPATHLEN,%ecx /* Brute force!!! */
movl $R(_kernelname),%edi
cmpb $'/',(%esi) /* Make sure it starts with a slash */
je 1f
movb $'/',(%edi)
incl %edi
decl %ecx
1:
cld
rep
movsb
2:
/*
* Determine the size of the boot loader's copy of the bootinfo
* struct. This is impossible to do properly because old versions
* of the struct don't contain a size field and there are 2 old
* versions with the same version number.
*/
movl $BI_ENDCOMMON,%ecx /* prepare for sizeless version */
testl $RB_BOOTINFO,8(%ebp) /* bi_size (and bootinfo) valid? */
je got_bi_size /* no, sizeless version */
movl BI_SIZE(%ebx),%ecx
got_bi_size:
/*
* Copy the common part of the bootinfo struct
*/
movl %ebx,%esi
movl $R(_bootinfo),%edi
cmpl $BOOTINFO_SIZE,%ecx
jbe got_common_bi_size
movl $BOOTINFO_SIZE,%ecx
got_common_bi_size:
cld
rep
movsb
#ifdef NFS
/*
* If we have a nfs_diskless structure copy it in
*/
movl BI_NFS_DISKLESS(%ebx),%esi
cmpl $0,%esi
je olddiskboot
movl $R(_nfs_diskless),%edi
movl $NFSDISKLESS_SIZE,%ecx
cld
rep
movsb
movl $R(_nfs_diskless_valid),%edi
movl $1,(%edi)
#endif
/*
* The old style disk boot.
* (*btext)(howto, bootdev, cyloffset, esym);
* Note that the newer boot code just falls into here to pick
* up howto and bootdev, cyloffset and esym are no longer used
*/
olddiskboot:
movl 8(%ebp),%eax
movl %eax,R(_boothowto)
movl 12(%ebp),%eax
movl %eax,R(_bootdev)
#if defined(USERCONFIG_BOOT) && defined(USERCONFIG)
#ifdef PC98
movl $0x90200, %esi
#else
movl $0x10200, %esi
#endif
movl $R(_userconfig_from_boot),%edi
movl $512,%ecx
cld
rep
movsb
#endif /* USERCONFIG_BOOT */
ret
/**********************************************************************
*
* Identify the CPU and initialize anything special about it
*
*/
identify_cpu:
/* Try to toggle alignment check flag; does not exist on 386. */
pushfl
popl %eax
movl %eax,%ecx
orl $PSL_AC,%eax
pushl %eax
popfl
pushfl
popl %eax
xorl %ecx,%eax
andl $PSL_AC,%eax
pushl %ecx
popfl
testl %eax,%eax
jnz 1f
movl $CPU_386,R(_cpu)
jmp 3f
1: /* Try to toggle identification flag; does not exist on early 486s. */
pushfl
popl %eax
movl %eax,%ecx
xorl $PSL_ID,%eax
pushl %eax
popfl
pushfl
popl %eax
xorl %ecx,%eax
andl $PSL_ID,%eax
pushl %ecx
popfl
testl %eax,%eax
jnz 1f
movl $CPU_486,R(_cpu)
/* check for Cyrix 486DLC -- based on check routine */
/* documented in "Cx486SLC/e SMM Programmer's Guide" */
xorw %dx,%dx
cmpw %dx,%dx # set flags to known state
pushfw
popw %cx # store flags in ecx
movw $0xffff,%ax
movw $0x0004,%bx
divw %bx
pushfw
popw %ax
andw $0x08d5,%ax # mask off important bits
andw $0x08d5,%cx
cmpw %ax,%cx
jnz 3f # if flags changed, Intel chip
movl $CPU_486DLC,R(_cpu) # set CPU value for Cyrix
movl $0x69727943,R(_cpu_vendor) # store vendor string
movw $0x0078,R(_cpu_vendor+4)
#ifndef CYRIX_CACHE_WORKS
/* Disable caching of the ISA hole only. */
invd
movb $CCR0,%al # Configuration Register index (CCR0)
outb %al,$0x22
inb $0x23,%al
orb $(CCR0_NC1|CCR0_BARB),%al
movb %al,%ah
movb $CCR0,%al
outb %al,$0x22
movb %ah,%al
outb %al,$0x23
invd
#else /* CYRIX_CACHE_WORKS */
/* Set cache parameters */
invd # Start with guaranteed clean cache
movb $CCR0,%al # Configuration Register index (CCR0)
outb %al,$0x22
inb $0x23,%al
andb $~CCR0_NC0,%al
#ifndef CYRIX_CACHE_REALLY_WORKS
orb $(CCR0_NC1|CCR0_BARB),%al
#else /* CYRIX_CACHE_REALLY_WORKS */
orb $CCR0_NC1,%al
#endif /* !CYRIX_CACHE_REALLY_WORKS */
movb %al,%ah
movb $CCR0,%al
outb %al,$0x22
movb %ah,%al
outb %al,$0x23
/* clear non-cacheable region 1 */
movb $(NCR1+2),%al
outb %al,$0x22
movb $NCR_SIZE_0K,%al
outb %al,$0x23
/* clear non-cacheable region 2 */
movb $(NCR2+2),%al
outb %al,$0x22
movb $NCR_SIZE_0K,%al
outb %al,$0x23
/* clear non-cacheable region 3 */
movb $(NCR3+2),%al
outb %al,$0x22
movb $NCR_SIZE_0K,%al
outb %al,$0x23
/* clear non-cacheable region 4 */
movb $(NCR4+2),%al
outb %al,$0x22
movb $NCR_SIZE_0K,%al
outb %al,$0x23
/* enable caching in CR0 */
movl %cr0,%eax
andl $~(CR0_CD|CR0_NW),%eax
movl %eax,%cr0
invd
#endif /* !CYRIX_CACHE_WORKS */
jmp 3f
1: /* Use the `cpuid' instruction. */
xorl %eax,%eax
.byte 0x0f,0xa2 # cpuid 0
movl %eax,R(_cpu_high) # highest capability
movl %ebx,R(_cpu_vendor) # store vendor string
movl %edx,R(_cpu_vendor+4)
movl %ecx,R(_cpu_vendor+8)
movb $0,R(_cpu_vendor+12)
movl $1,%eax
.byte 0x0f,0xa2 # cpuid 1
movl %eax,R(_cpu_id) # store cpu_id
movl %edx,R(_cpu_feature) # store cpu_feature
rorl $8,%eax # extract family type
andl $15,%eax
cmpl $5,%eax
jae 1f
/* less than Pentium; must be 486 */
movl $CPU_486,R(_cpu)
jmp 3f
1:
/* a Pentium? */
cmpl $5,%eax
jne 2f
movl $CPU_586,R(_cpu)
jmp 3f
2:
/* Greater than Pentium...call it a Pentium Pro */
movl $CPU_686,R(_cpu)
3:
ret
/**********************************************************************
*
* Create the first page directory and its page tables.
*
*/
create_pagetables:
testl $CPUID_PGE, R(_cpu_feature)
jz 1f
movl %cr4, %eax
orl $CR4_PGE, %eax
movl %eax, %cr4
1:
/* Find end of kernel image (rounded up to a page boundary). */
movl $R(_end),%esi
/* include symbols in "kernel image" if they are loaded and useful */
#ifdef DDB
movl R(_bootinfo+BI_ESYMTAB),%edi
testl %edi,%edi
je over_symalloc
movl %edi,%esi
movl $KERNBASE,%edi
addl %edi,R(_bootinfo+BI_SYMTAB)
addl %edi,R(_bootinfo+BI_ESYMTAB)
over_symalloc:
#endif
addl $PAGE_MASK,%esi
andl $~PAGE_MASK,%esi
movl %esi,R(_KERNend) /* save end of kernel */
movl %esi,R(physfree) /* next free page is at end of kernel */
/* Allocate Kernel Page Tables */
ALLOCPAGES(NKPT)
movl %esi,R(_KPTphys)
/* Allocate Page Table Directory */
ALLOCPAGES(1)
movl %esi,R(_IdlePTD)
/* Allocate UPAGES */
ALLOCPAGES(UPAGES)
movl %esi,R(p0upa)
addl $KERNBASE, %esi
movl %esi, R(_proc0paddr)
/* Allocate proc0's page table for the UPAGES. */
ALLOCPAGES(1)
movl %esi,R(p0upt)
/* Map read-only from zero to the end of the kernel text section */
xorl %eax, %eax
#ifdef BDE_DEBUGGER
/* If the debugger is present, actually map everything read-write. */
cmpl $0,R(_bdb_exists)
jne map_read_write
#endif
xorl %edx,%edx
testl $CPUID_PGE, R(_cpu_feature)
jz 2f
orl $PG_G,%edx
2: movl $R(_etext),%ecx
addl $PAGE_MASK,%ecx
shrl $PAGE_SHIFT,%ecx
fillkptphys(%edx)
/* Map read-write, data, bss and symbols */
movl $R(_etext),%eax
addl $PAGE_MASK, %eax
andl $~PAGE_MASK, %eax
map_read_write:
movl $PG_RW,%edx
testl $CPUID_PGE, R(_cpu_feature)
jz 1f
orl $PG_G,%edx
1: movl R(_KERNend),%ecx
subl %eax,%ecx
shrl $PAGE_SHIFT,%ecx
fillkptphys(%edx)
/* Map page directory. */
movl R(_IdlePTD), %eax
movl $1, %ecx
fillkptphys($PG_RW)
/* Map proc0's page table for the UPAGES. */
movl R(p0upt), %eax
movl $1, %ecx
fillkptphys($PG_RW)
/* Map proc0's UPAGES in the physical way ... */
movl R(p0upa), %eax
movl $UPAGES, %ecx
fillkptphys($PG_RW)
/* Map ISA hole */
movl $ISA_HOLE_START, %eax
movl $ISA_HOLE_LENGTH>>PAGE_SHIFT, %ecx
fillkptphys($PG_RW)
/* Map proc0s UPAGES in the special page table for this purpose ... */
movl R(p0upa), %eax
movl $KSTKPTEOFF, %ebx
movl $UPAGES, %ecx
fillkpt(R(p0upt), $PG_RW)
/* ... and put the page table in the pde. */
movl R(p0upt), %eax
movl $KSTKPTDI, %ebx
movl $1, %ecx
fillkpt(R(_IdlePTD), $PG_RW)
/* install a pde for temporary double map of bottom of VA */
movl R(_KPTphys), %eax
xorl %ebx, %ebx
movl $1, %ecx
fillkpt(R(_IdlePTD), $PG_RW)
/* install pde's for pt's */
movl R(_KPTphys), %eax
movl $KPTDI, %ebx
movl $NKPT, %ecx
fillkpt(R(_IdlePTD), $PG_RW)
/* install a pde recursively mapping page directory as a page table */
movl R(_IdlePTD), %eax
movl $PTDPTDI, %ebx
movl $1,%ecx
fillkpt(R(_IdlePTD), $PG_RW)
ret
#ifdef BDE_DEBUGGER
bdb_prepare_paging:
cmpl $0,R(_bdb_exists)
je bdb_prepare_paging_exit
subl $6,%esp
/*
* Copy and convert debugger entries from the bootstrap gdt and idt
* to the kernel gdt and idt. Everything is still in low memory.
* Tracing continues to work after paging is enabled because the
* low memory addresses remain valid until everything is relocated.
* However, tracing through the setidt() that initializes the trace
* trap will crash.
*/
sgdt (%esp)
movl 2(%esp),%esi /* base address of bootstrap gdt */
movl $R(_gdt),%edi
movl %edi,2(%esp) /* prepare to load kernel gdt */
movl $8*18/4,%ecx
cld
rep /* copy gdt */
movsl
movl $R(_gdt),-8+2(%edi) /* adjust gdt self-ptr */
movb $0x92,-8+5(%edi)
lgdt (%esp)
sidt (%esp)
movl 2(%esp),%esi /* base address of current idt */
movl 8+4(%esi),%eax /* convert dbg descriptor to ... */
movw 8(%esi),%ax
movl %eax,R(bdb_dbg_ljmp+1) /* ... immediate offset ... */
movl 8+2(%esi),%eax
movw %ax,R(bdb_dbg_ljmp+5) /* ... and selector for ljmp */
movl 24+4(%esi),%eax /* same for bpt descriptor */
movw 24(%esi),%ax
movl %eax,R(bdb_bpt_ljmp+1)
movl 24+2(%esi),%eax
movw %ax,R(bdb_bpt_ljmp+5)
movl $R(_idt),%edi
movl %edi,2(%esp) /* prepare to load kernel idt */
movl $8*4/4,%ecx
cld
rep /* copy idt */
movsl
lidt (%esp)
addl $6,%esp
bdb_prepare_paging_exit:
ret
/* Relocate debugger gdt entries and gdt and idt pointers. */
bdb_commit_paging:
cmpl $0,_bdb_exists
je bdb_commit_paging_exit
movl $_gdt+8*9,%eax /* adjust slots 9-17 */
movl $9,%ecx
reloc_gdt:
movb $KERNBASE>>24,7(%eax) /* top byte of base addresses, was 0, */
addl $8,%eax /* now KERNBASE>>24 */
loop reloc_gdt
subl $6,%esp
sgdt (%esp)
addl $KERNBASE,2(%esp)
lgdt (%esp)
sidt (%esp)
addl $KERNBASE,2(%esp)
lidt (%esp)
addl $6,%esp
int $3
bdb_commit_paging_exit:
ret
#endif /* BDE_DEBUGGER */