freebsd-skq/sys/i386/i386/locore.s
David Greenman 269312019a * Applied fixes from Bruce Evans to fix COW bugs, >1MB kernel loading,
profiling, and various protection checks that cause security holes
  and system crashes.
* Changed min/max/bcmp/ffs/strlen to be static inline functions
  - included from cpufunc.h in via systm.h. This change
  improves performance in many parts of the kernel - up to 5% in the
  networking layer alone. Note that this requires systm.h to be included
  in any file that uses these functions otherwise it won't be able to
  find them during the load.
* Fixed incorrect call to splx() in if_is.c
* Fixed bogus variable assignment to splx() in if_ed.c
1993-07-27 10:52:31 +00:00

2158 lines
47 KiB
ArmAsm

/*-
* 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.
*
* @(#)locore.s 7.3 (Berkeley) 5/13/91
*
* PATCHES MAGIC LEVEL PATCH THAT GOT US HERE
* -------------------- ----- ----------------------
* CURRENT PATCH LEVEL: 5 00158
* -------------------- ----- ----------------------
*
* 06 Aug 92 Pace Willisson Allow VGA memory to be mapped
* 28 Nov 92 Frank MacLachlan Aligned addresses and data
* on 32bit boundaries.
* 25 Mar 93 Kevin Lahey Add syscall counter for vmstat
* 20 Apr 93 Bruce Evans New npx-0.5 code
* 25 Apr 93 Bruce Evans Support new interrupt code (intr-0.1)
*/
/*
* locore.s: 4BSD machine support for the Intel 386
* Preliminary version
* Written by William F. Jolitz, 386BSD Project
*/
#include "assym.s"
#include "machine/psl.h"
#include "machine/pte.h"
#include "errno.h"
#include "machine/trap.h"
#include "machine/specialreg.h"
#include "i386/isa/debug.h"
#define KDSEL 0x10
#define SEL_RPL_MASK 0x0003
#define TRAPF_CS_OFF (13 * 4)
/*
* 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.
*/
.set IDXSHIFT,10
.set SYSTEM,0xFE000000 # virtual address of system start
/*note: gas copys sign bit (e.g. arithmetic >>), can't do SYSTEM>>22! */
.set SYSPDROFF,0x3F8 # Page dir index of System Base
/*
* Macros
*/
#define ALIGN_DATA .align 2
#define ALIGN_TEXT .align 2,0x90 /* 4-byte boundaries, NOP-filled */
#define SUPERALIGN_TEXT .align 4,0x90 /* 16-byte boundaries better for 486 */
#define GEN_ENTRY(name) ALIGN_TEXT; .globl name; name:
#define NON_GPROF_ENTRY(name) GEN_ENTRY(_/**/name)
#ifdef GPROF
/*
* ALTENTRY() must be before a corresponding ENTRY() so that it can jump
* over the mcounting.
*/
#define ALTENTRY(name) GEN_ENTRY(_/**/name); MCOUNT; jmp 2f
#define ENTRY(name) GEN_ENTRY(_/**/name); MCOUNT; 2:
/*
* The call to mcount supports the usual (bad) conventions. We allocate
* some data and pass a pointer to it although the 386BSD doesn't use
* the data. We set up a frame before calling mcount because that is
* the standard convention although it makes work for both mcount and
* callers.
*/
#define MCOUNT .data; ALIGN_DATA; 1:; .long 0; .text; \
pushl %ebp; movl %esp, %ebp; \
movl $1b,%eax; call mcount; popl %ebp
#else
/*
* ALTENTRY() has to align because it is before a corresponding ENTRY().
* ENTRY() has to align to because there may be no ALTENTRY() before it.
* If there is a previous ALTENTRY() then the alignment code is empty.
*/
#define ALTENTRY(name) GEN_ENTRY(_/**/name)
#define ENTRY(name) GEN_ENTRY(_/**/name)
#endif
/* NB: NOP now preserves registers so NOPs can be inserted anywhere */
/* XXX: NOP and FASTER_NOP are misleadingly named */
#ifdef BROKEN_HARDWARE_AND_OR_SOFTWARE /* XXX - rarely necessary */
#define FASTER_NOP pushl %eax ; inb $0x84,%al ; popl %eax
#define NOP pushl %eax ; inb $0x84,%al ; inb $0x84,%al ; popl %eax
#else
#define FASTER_NOP
#define NOP
#endif
/*
* PTmap is recursive pagemap at top of virtual address space.
* Within PTmap, the page directory can be found (third indirection).
*/
.set PDRPDROFF,0x3F7 # Page dir index of Page dir
.globl _PTmap, _PTD, _PTDpde, _Sysmap
.set _PTmap,0xFDC00000
.set _PTD,0xFDFF7000
.set _Sysmap,0xFDFF8000
.set _PTDpde,0xFDFF7000+4*PDRPDROFF
/*
* APTmap, APTD is the alternate recursive pagemap.
* It's used when modifying another process's page tables.
*/
.set APDRPDROFF,0x3FE # Page dir index of Page dir
.globl _APTmap, _APTD, _APTDpde
.set _APTmap,0xFF800000
.set _APTD,0xFFBFE000
.set _APTDpde,0xFDFF7000+4*APDRPDROFF
/*
* Access to each processes kernel stack is via a region of
* per-process address space (at the beginning), immediatly above
* the user process stack.
*/
.globl _kstack
.set _kstack, USRSTACK
.set PPDROFF,0x3F6
.set PPTEOFF,0x400-UPAGES # 0x3FE
/*****************************************************************************/
/* Globals */
/*****************************************************************************/
.data
.globl _boothowto, _bootdev, _curpcb
.globl __ucodesel,__udatasel
.globl _cpu, _cold, _atdevbase
_cpu: .long 0 # are we 386, 386sx, or 486
_cold: .long 1 # cold till we are not
_atdevbase: .long 0 # location of start of iomem in virtual
# .nonglobl _atdevphys (should be register or something)
_atdevphys: .long 0 # location of device mapping ptes (phys)
.globl _IdlePTD, _KPTphys
_IdlePTD: .long 0
_KPTphys: .long 0
.globl _cyloffset, _proc0paddr
_cyloffset: .long 0
_proc0paddr: .long 0
#ifdef SHOW_A_LOT
bit_colors:
.byte GREEN,RED,0,0
#endif
.space 512
tmpstk:
.text
/*****************************************************************************/
/* System Initialisation */
/*****************************************************************************/
/*
* btext: beginning of text section.
* Also the entry point (jumped to directly from the boot blocks).
*/
ENTRY(btext)
movw $0x1234, 0x472 # warm boot
jmp 1f
.space 0x500 # skip over warm boot shit
/*
* pass parameters on stack (howto, bootdev, unit, cyloffset)
* note: (%esp) is return address of boot
* ( if we want to hold onto /boot, it's physical %esp up to _end)
*/
1: movl 4(%esp),%eax
movl %eax,_boothowto-SYSTEM
movl 8(%esp),%eax
movl %eax,_bootdev-SYSTEM
movl 12(%esp),%eax
movl %eax, _cyloffset-SYSTEM
/*
* Finished with old stack; load new %esp now instead of later so
* we can trace this code without having to worry about the trace
* trap clobbering the memory test or the zeroing of the bss+bootstrap
* page tables.
*
* XXX - wdboot clears the bss after testing that this is safe.
* This is too wasteful - memory below 640K is scarce. The boot
* program should check:
* text+data <= &stack_variable - more_space_for_stack
* text+data+bss+pad+space_for_page_tables <= end_of_memory
* Oops, the gdt is in the carcass of the boot program so clearing
* the rest of memory is still not possible.
*/
movl $ tmpstk-SYSTEM,%esp # bootstrap stack end location
#ifdef garbage
/* count up memory */
xorl %eax,%eax # start with base memory at 0x0
#movl $ 0xA0000/NBPG,%ecx # look every 4K up to 640K
movl $ 0xA0,%ecx # look every 4K up to 640K
1: movl (%eax),%ebx # save location to check
movl $0xa55a5aa5,(%eax) # write test pattern
/* flush stupid cache here! (with bcopy (0,0,512*1024) ) */
cmpl $0xa55a5aa5,(%eax) # does not check yet for rollover
jne 2f
movl %ebx,(%eax) # restore memory
addl $ NBPG,%eax
loop 1b
2: shrl $12,%eax
movl %eax,_Maxmem-SYSTEM
movl $0x100000,%eax # next, talley remaining memory
#movl $((0xFFF000-0x100000)/NBPG),%ecx
movl $(0xFFF-0x100),%ecx
1: movl (%eax),%ebx # save location to check
movl $0xa55a5aa5,(%eax) # write test pattern
cmpl $0xa55a5aa5,(%eax) # does not check yet for rollover
jne 2f
movl %ebx,(%eax) # restore memory
addl $ NBPG,%eax
loop 1b
2: shrl $12,%eax
movl %eax,_Maxmem-SYSTEM
#endif
/* find end of kernel image */
movl $_end-SYSTEM,%ecx
addl $ NBPG-1,%ecx
andl $~(NBPG-1),%ecx
movl %ecx,%esi
/* clear bss and memory for bootstrap pagetables. */
movl $_edata-SYSTEM,%edi
subl %edi,%ecx
addl $(UPAGES+5)*NBPG,%ecx
/*
* Virtual address space of kernel:
*
* text | data | bss | page dir | proc0 kernel stack | usr stk map | Sysmap
* 0 1 2 3 4
*/
xorl %eax,%eax # pattern
cld
rep
stosb
movl %esi,_IdlePTD-SYSTEM /*physical address of Idle Address space */
#define fillkpt \
1: movl %eax,(%ebx) ; \
addl $ NBPG,%eax ; /* increment physical address */ \
addl $4,%ebx ; /* next pte */ \
loop 1b ;
/*
* Map Kernel
* N.B. don't bother with making kernel text RO, as 386
* ignores R/W AND U/S bits on kernel access (only v works) !
*
* First step - build page tables
*/
movl %esi,%ecx # this much memory,
shrl $ PGSHIFT,%ecx # for this many pte s
addl $ UPAGES+4,%ecx # including our early context
cmpl $0xa0,%ecx # XXX - cover debugger pages
jae 1f
movl $0xa0,%ecx
1:
movl $PG_V|PG_KW,%eax # having these bits set,
lea (4*NBPG)(%esi),%ebx # physical address of KPT in proc 0,
movl %ebx,_KPTphys-SYSTEM # in the kernel page table,
fillkpt
/* map I/O memory map */
movl $0x100-0xa0,%ecx # for this many pte s,
movl $(0xa0000|PG_V|PG_UW),%eax # having these bits set,(perhaps URW?) XXX 06 Aug 92
movl %ebx,_atdevphys-SYSTEM # remember phys addr of ptes
fillkpt
/* map proc 0's kernel stack into user page table page */
movl $ UPAGES,%ecx # for this many pte s,
lea (1*NBPG)(%esi),%eax # physical address in proc 0
lea (SYSTEM)(%eax),%edx
movl %edx,_proc0paddr-SYSTEM # remember VA for 0th process init
orl $PG_V|PG_KW,%eax # having these bits set,
lea (3*NBPG)(%esi),%ebx # physical address of stack pt in proc 0
addl $(PPTEOFF*4),%ebx
fillkpt
/*
* Construct a page table directory
* (of page directory elements - pde's)
*/
/* install a pde for temporary double map of bottom of VA */
lea (4*NBPG)(%esi),%eax # physical address of kernel page table
orl $ PG_V|PG_UW,%eax # pde entry is valid XXX 06 Aug 92
movl %eax,(%esi) # which is where temp maps!
/* kernel pde's */
movl $ 3,%ecx # for this many pde s,
lea (SYSPDROFF*4)(%esi), %ebx # offset of pde for kernel
fillkpt
/* install a pde recursively mapping page directory as a page table! */
movl %esi,%eax # phys address of ptd in proc 0
orl $ PG_V|PG_UW,%eax # pde entry is valid XXX 06 Aug 92
movl %eax, PDRPDROFF*4(%esi) # which is where PTmap maps!
/* install a pde to map kernel stack for proc 0 */
lea (3*NBPG)(%esi),%eax # physical address of pt in proc 0
orl $PG_V|PG_KW,%eax # pde entry is valid
movl %eax,PPDROFF*4(%esi) # which is where kernel stack maps!
/* copy and convert stuff from old gdt and idt for debugger */
cmpl $0x0375c339,0x96104 # XXX - debugger signature
jne 1f
movb $1,_bdb_exists-SYSTEM
1:
pushal
subl $2*6,%esp
sgdt (%esp)
movl 2(%esp),%esi # base address of current gdt
movl $_gdt-SYSTEM,%edi
movl %edi,2(%esp)
movl $8*18/4,%ecx
rep # copy gdt
movsl
movl $_gdt-SYSTEM,-8+2(%edi) # adjust gdt self-ptr
movb $0x92,-8+5(%edi)
sidt 6(%esp)
movl 6+2(%esp),%esi # base address of current idt
movl 8+4(%esi),%eax # convert dbg descriptor to ...
movw 8(%esi),%ax
movl %eax,bdb_dbg_ljmp+1-SYSTEM # ... immediate offset ...
movl 8+2(%esi),%eax
movw %ax,bdb_dbg_ljmp+5-SYSTEM # ... and selector for ljmp
movl 24+4(%esi),%eax # same for bpt descriptor
movw 24(%esi),%ax
movl %eax,bdb_bpt_ljmp+1-SYSTEM
movl 24+2(%esi),%eax
movw %ax,bdb_bpt_ljmp+5-SYSTEM
movl $_idt-SYSTEM,%edi
movl %edi,6+2(%esp)
movl $8*4/4,%ecx
rep # copy idt
movsl
lgdt (%esp)
lidt 6(%esp)
addl $2*6,%esp
popal
/* load base of page directory, and enable mapping */
movl %esi,%eax # phys address of ptd in proc 0
orl $ I386_CR3PAT,%eax
movl %eax,%cr3 # load ptd addr into mmu
movl %cr0,%eax # get control word
/*
* XXX it is now safe to always (attempt to) set CR0_WP and to set up
* the page tables assuming it works, so USE_486_WRITE_PROTECT will go
* away. The special 386 PTE checking needs to be conditional on
* whatever distingiushes 486-only kernels from 386-486 kernels.
*/
#ifdef USE_486_WRITE_PROTECT
orl $CR0_PE|CR0_PG|CR0_WP,%eax # and let s page!
#else
orl $CR0_PE|CR0_PG,%eax # and let s page!
#endif
movl %eax,%cr0 # NOW!
pushl $begin # jump to high mem!
ret
begin: /* now running relocated at SYSTEM where the system is linked to run */
.globl _Crtat # XXX - locore should not know about
movl _Crtat,%eax # variables of device drivers (pccons)!
subl $0xfe0a0000,%eax
movl _atdevphys,%edx # get pte PA
subl _KPTphys,%edx # remove base of ptes, now have phys offset
shll $ PGSHIFT-2,%edx # corresponding to virt offset
addl $ SYSTEM,%edx # add virtual base
movl %edx, _atdevbase
addl %eax,%edx
movl %edx,_Crtat
/* set up bootstrap stack */
movl $ _kstack+UPAGES*NBPG-4*12,%esp # bootstrap stack end location
xorl %eax,%eax # mark end of frames
movl %eax,%ebp
movl _proc0paddr, %eax
movl %esi, PCB_CR3(%eax)
lea 7*NBPG(%esi),%esi # skip past stack.
pushl %esi
/* relocate debugger gdt entries */
movl $_gdt+8*9,%eax # adjust slots 9-17
movl $9,%ecx
reloc_gdt:
movb $0xfe,7(%eax) # top byte of base addresses, was 0,
addl $8,%eax # now SYSTEM>>24
loop reloc_gdt
cmpl $0,_bdb_exists
je 1f
int $3
1:
call _init386 # wire 386 chip for unix operation
movl $0,_PTD
call _main # autoconfiguration, mountroot etc
popl %esi
/*
* 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
# build outer stack frame
pushl %ecx # user ss
pushl $ USRSTACK # user esp
pushl %eax # user cs
pushl $0 # user ip
movl %cx,%ds
movl %cx,%es
movl %ax,%fs # double map cs to fs
movl %cx,%gs # and ds to gs
lret # goto user!
pushl $lretmsg1 /* "should never get here!" */
call _panic
lretmsg1:
.asciz "lret: toinit\n"
.set exec,59
.set exit,1
#define LCALL(x,y) .byte 0x9a ; .long y; .word x
/*
* Icode is copied out to process 1 and executed in user mode:
* execve("/sbin/init", argv, envp); exit(0);
* If the execve fails, process 1 exits and the system panics.
*/
NON_GPROF_ENTRY(icode)
pushl $0 # envp
# pushl $argv-_icode # gas fucks up again
movl $argv,%eax
subl $_icode,%eax
pushl %eax
# pushl $init-_icode
movl $init,%eax
subl $_icode,%eax
pushl %eax
pushl %eax # junk to fake return address
movl $exec,%eax
LCALL(0x7,0x0)
pushl %eax # execve failed, the errno will do for an
# exit code because errnos are < 128
pushl %eax # junk to fake return address
movl $exit,%eax
LCALL(0x7,0x0)
init:
.asciz "/sbin/init"
ALIGN_DATA
argv:
.long init+6-_icode # argv[0] = "init" ("/sbin/init" + 6)
.long eicode-_icode # argv[1] follows icode after copyout
.long 0
eicode:
.globl _szicode
_szicode:
.long _szicode-_icode
NON_GPROF_ENTRY(sigcode)
call 12(%esp)
lea 28(%esp),%eax # scp (the call may have clobbered the
# copy at 8(%esp))
# XXX - use genassym
pushl %eax
pushl %eax # junk to fake return address
movl $103,%eax # sigreturn()
LCALL(0x7,0) # enter kernel with args on stack
hlt # never gets here
.globl _szsigcode
_szsigcode:
.long _szsigcode-_sigcode
/*****************************************************************************/
/* support routines for GCC, general C-callable functions */
/*****************************************************************************/
ENTRY(__udivsi3)
movl 4(%esp),%eax
xorl %edx,%edx
divl 8(%esp)
ret
ENTRY(__divsi3)
movl 4(%esp),%eax
cltd
idivl 8(%esp)
ret
/*
* I/O bus instructions via C
*/
ENTRY(outb) # outb (port, val)
movl 4(%esp),%edx
NOP
movl 8(%esp),%eax
outb %al,%dx
NOP
ret
ENTRY(outw) # outw (port, val)
movl 4(%esp),%edx
NOP
movl 8(%esp),%eax
outw %ax,%dx
NOP
ret
ENTRY(outsb) # outsb(port,addr,cnt)
pushl %esi
movw 8(%esp),%dx
movl 12(%esp),%esi
movl 16(%esp),%ecx
cld
NOP
rep
outsb
NOP
movl %esi,%eax
popl %esi
ret
ENTRY(outsw) # outsw(port,addr,cnt)
pushl %esi
movw 8(%esp),%dx
movl 12(%esp),%esi
movl 16(%esp),%ecx
cld
NOP
rep
outsw
NOP
movl %esi,%eax
popl %esi
ret
ENTRY(inb) # val = inb (port)
movl 4(%esp),%edx
subl %eax,%eax # clr eax
NOP
inb %dx,%al
ret
ENTRY(inw) # val = inw (port)
movl 4(%esp),%edx
subl %eax,%eax # clr eax
NOP
inw %dx,%ax
ret
ENTRY(insb) # insb(port,addr,cnt)
pushl %edi
movw 8(%esp),%dx
movl 12(%esp),%edi
movl 16(%esp),%ecx
cld
NOP
rep
insb
NOP
movl %edi,%eax
popl %edi
ret
ENTRY(insw) # insw(port,addr,cnt)
pushl %edi
movw 8(%esp),%dx
movl 12(%esp),%edi
movl 16(%esp),%ecx
cld
NOP
rep
insw
NOP
movl %edi,%eax
popl %edi
ret
ENTRY(rtcin)
movl 4(%esp),%eax
outb %al,$0x70
subl %eax,%eax # clr eax
inb $0x71,%al
ret
/*
* bcopy family
*/
ENTRY(bzero) # void bzero(void *base, u_int cnt)
pushl %edi
movl 8(%esp),%edi
movl 12(%esp),%ecx
xorl %eax,%eax
shrl $2,%ecx
cld
rep
stosl
movl 12(%esp),%ecx
andl $3,%ecx
rep
stosb
popl %edi
ret
ENTRY(fillw) # fillw (pat,base,cnt)
pushl %edi
movl 8(%esp),%eax
movl 12(%esp),%edi
movl 16(%esp),%ecx
cld
rep
stosw
popl %edi
ret
ENTRY(bcopyb)
bcopyb:
pushl %esi
pushl %edi
movl 12(%esp),%esi
movl 16(%esp),%edi
movl 20(%esp),%ecx
cmpl %esi,%edi /* potentially overlapping? */
jnb 1f
cld /* nope, copy forwards */
rep
movsb
popl %edi
popl %esi
ret
ALIGN_TEXT
1:
addl %ecx,%edi /* copy backwards. */
addl %ecx,%esi
std
decl %edi
decl %esi
rep
movsb
popl %edi
popl %esi
cld
ret
ENTRY(bcopyw)
bcopyw:
pushl %esi
pushl %edi
movl 12(%esp),%esi
movl 16(%esp),%edi
movl 20(%esp),%ecx
cmpl %esi,%edi /* potentially overlapping? */
jnb 1f
cld /* nope, copy forwards */
shrl $1,%ecx /* copy by 16-bit words */
rep
movsw
adc %ecx,%ecx /* any bytes left? */
rep
movsb
popl %edi
popl %esi
ret
ALIGN_TEXT
1:
addl %ecx,%edi /* copy backwards */
addl %ecx,%esi
std
andl $1,%ecx /* any fractional bytes? */
decl %edi
decl %esi
rep
movsb
movl 20(%esp),%ecx /* copy remainder by 16-bit words */
shrl $1,%ecx
decl %esi
decl %edi
rep
movsw
popl %edi
popl %esi
cld
ret
ENTRY(bcopyx)
movl 16(%esp),%eax
cmpl $2,%eax
je bcopyw /* not _bcopyw, to avoid multiple mcounts */
cmpl $4,%eax
je bcopy
jmp bcopyb
/*
* (ov)bcopy (src,dst,cnt)
* ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
*/
ALTENTRY(ovbcopy)
ENTRY(bcopy)
bcopy:
pushl %esi
pushl %edi
movl 12(%esp),%esi
movl 16(%esp),%edi
movl 20(%esp),%ecx
cmpl %esi,%edi /* potentially overlapping? */
jnb 1f
cld /* nope, copy forwards */
shrl $2,%ecx /* copy by 32-bit words */
rep
movsl
movl 20(%esp),%ecx
andl $3,%ecx /* any bytes left? */
rep
movsb
popl %edi
popl %esi
ret
ALIGN_TEXT
1:
addl %ecx,%edi /* copy backwards */
addl %ecx,%esi
std
andl $3,%ecx /* any fractional bytes? */
decl %edi
decl %esi
rep
movsb
movl 20(%esp),%ecx /* copy remainder by 32-bit words */
shrl $2,%ecx
subl $3,%esi
subl $3,%edi
rep
movsl
popl %edi
popl %esi
cld
ret
ALTENTRY(ntohl)
ENTRY(htonl)
movl 4(%esp),%eax
#ifdef i486
/* XXX */
/* Since Gas 1.38 does not grok bswap this has been coded as the
* equivalent bytes. This can be changed back to bswap when we
* upgrade to a newer version of Gas */
/* bswap %eax */
.byte 0x0f
.byte 0xc8
#else
xchgb %al,%ah
roll $16,%eax
xchgb %al,%ah
#endif
ret
ALTENTRY(ntohs)
ENTRY(htons)
movzwl 4(%esp),%eax
xchgb %al,%ah
ret
#ifdef SHOW_A_LOT
/*
* 'show_bits' was too big when defined as a macro. The line length for some
* enclosing macro was too big for gas. Perhaps the code would have blown
* the cache anyway.
*/
ALIGN_TEXT
show_bits:
pushl %eax
SHOW_BIT(0)
SHOW_BIT(1)
SHOW_BIT(2)
SHOW_BIT(3)
SHOW_BIT(4)
SHOW_BIT(5)
SHOW_BIT(6)
SHOW_BIT(7)
SHOW_BIT(8)
SHOW_BIT(9)
SHOW_BIT(10)
SHOW_BIT(11)
SHOW_BIT(12)
SHOW_BIT(13)
SHOW_BIT(14)
SHOW_BIT(15)
popl %eax
ret
#endif /* SHOW_A_LOT */
/*****************************************************************************/
/* copyout and fubyte family */
/*****************************************************************************/
/*
* Access user memory from inside the kernel. These routines and possibly
* the math- and DOS emulators should be the only places that do this.
*
* We have to access the memory with user's permissions, so use a segment
* selector with RPL 3. For writes to user space we have to additionally
* check the PTE for write permission, because the 386 does not check
* write permissions when we are executing with EPL 0. The 486 does check
* this if the WP bit is set in CR0, so we can use a simpler version here.
*
* These routines set curpcb->onfault for the time they execute. When a
* protection violation occurs inside the functions, the trap handler
* returns to *curpcb->onfault instead of the function.
*/
ENTRY(copyout) # copyout (from_kernel, to_user, len)
movl _curpcb, %eax
movl $copyout_fault, PCB_ONFAULT(%eax)
pushl %esi
pushl %edi
pushl %ebx
movl 16(%esp), %esi
movl 20(%esp), %edi
movl 24(%esp), %ebx
orl %ebx, %ebx # nothing to do?
jz done_copyout
/*
* Check explicitly for non-user addresses. If 486 write protection
* is being used, this check is essential because we are in kernel
* mode so the h/w does not provide any protection against writing
* kernel addresses.
*
* Otherwise, it saves having to load and restore %es to get the
* usual segment-based protection (the destination segment for movs
* is always %es). The other explicit checks for user-writablility
* are not quite sufficient. They fail for the user area because
* we mapped the user area read/write to avoid having an #ifdef in
* vm_machdep.c. They fail for user PTEs and/or PTDs! (107
* addresses including 0xff800000 and 0xfc000000). I'm not sure if
* this can be fixed. Marking the PTEs supervisor mode and the
* PDE's user mode would almost work, but there may be a problem
* with the self-referential PDE.
*/
movl %edi, %eax
addl %ebx, %eax
jc copyout_fault
#define VM_END_USER_ADDRESS 0xFDBFE000 /* XXX */
cmpl $VM_END_USER_ADDRESS, %eax
ja copyout_fault
#ifndef USE_486_WRITE_PROTECT
/*
* We have to check each PTE for user write permission.
* The checking may cause a page fault, so it is important to set
* up everything for return via copyout_fault before here.
*/
/* compute number of pages */
movl %edi, %ecx
andl $0x0fff, %ecx
addl %ebx, %ecx
decl %ecx
shrl $IDXSHIFT+2, %ecx
incl %ecx
/* compute PTE offset for start address */
movl %edi, %edx
shrl $IDXSHIFT, %edx
andb $0xfc, %dl
1: /* check PTE for each page */
movb _PTmap(%edx), %al
andb $0x07, %al /* Pages must be VALID + USERACC + WRITABLE */
cmpb $0x07, %al
je 2f
/* simulate a trap */
pushl %edx
pushl %ecx
shll $IDXSHIFT, %edx
pushl %edx
call _trapwrite /* XXX trapwrite(addr) */
popl %edx
popl %ecx
popl %edx
orl %eax, %eax /* if not ok, return EFAULT */
jnz copyout_fault
2:
addl $4, %edx
decl %ecx
jnz 1b /* check next page */
#endif /* ndef USE_486_WRITE_PROTECT */
/* now copy it over */
/* bcopy (%esi, %edi, %ebx) */
cld
movl %ebx, %ecx
shrl $2, %ecx
rep
movsl
movb %bl, %cl
andb $3, %cl
rep
movsb
done_copyout:
popl %ebx
popl %edi
popl %esi
xorl %eax,%eax
movl _curpcb,%edx
movl %eax,PCB_ONFAULT(%edx)
ret
ALIGN_TEXT
copyout_fault:
popl %ebx
popl %edi
popl %esi
movl _curpcb, %edx
movl $0, PCB_ONFAULT(%edx)
movl $EFAULT, %eax
ret
ENTRY(copyin) # copyin (from_user, to_kernel, len)
movl _curpcb,%eax
movl $copyin_fault, PCB_ONFAULT(%eax)
pushl %esi
pushl %edi
movl 12(%esp),%esi # caddr_t from
movl 16(%esp),%edi # caddr_t to
movl 20(%esp),%ecx # size_t len
movb %cl,%al
shrl $2,%ecx # copy longword-wise
cld
gs
rep
movsl
movb %al,%cl
andb $3,%cl # copy remaining bytes
gs
rep
movsb
popl %edi
popl %esi
xorl %eax, %eax
movl _curpcb, %edx
movl %eax, PCB_ONFAULT(%edx)
ret
ALIGN_TEXT
copyin_fault:
popl %edi
popl %esi
movl _curpcb, %edx
movl $0, PCB_ONFAULT(%edx)
movl $EFAULT, %eax
ret
/*
* fu{byte,sword,word} : fetch a byte (sword, word) from user memory
*/
ALTENTRY(fuiword)
ENTRY(fuword)
movl _curpcb,%ecx
movl $fusufault,PCB_ONFAULT(%ecx)
movl 4(%esp),%edx
gs
movl (%edx),%eax
movl $0,PCB_ONFAULT(%ecx)
ret
ENTRY(fusword)
movl _curpcb,%ecx
movl $fusufault,PCB_ONFAULT(%ecx)
movl 4(%esp),%edx
gs
movzwl (%edx),%eax
movl $0,PCB_ONFAULT(%ecx)
ret
ALTENTRY(fuibyte)
ENTRY(fubyte)
movl _curpcb,%ecx
movl $fusufault,PCB_ONFAULT(%ecx)
movl 4(%esp),%edx
gs
movzbl (%edx),%eax
movl $0,PCB_ONFAULT(%ecx)
ret
ALIGN_TEXT
fusufault:
movl _curpcb,%ecx
xorl %eax,%eax
movl %eax,PCB_ONFAULT(%ecx)
decl %eax
ret
/*
* su{byte,sword,word}: write a byte (word, longword) to user memory
*/
#ifdef USE_486_WRITE_PROTECT
/*
* we only have to set the right segment selector.
*/
ALTENTRY(suiword)
ENTRY(suword)
movl _curpcb,%ecx
movl $fusufault,PCB_ONFAULT(%ecx)
movl 4(%esp),%edx
movl 8(%esp),%eax
gs
movl %eax,(%edx)
xorl %eax,%eax
movl %eax,PCB_ONFAULT(%ecx)
ret
ENTRY(susword)
movl _curpcb,%ecx
movl $fusufault,PCB_ONFAULT(%ecx)
movl 4(%esp),%edx
movw 8(%esp),%ax
gs
movw %ax,(%edx)
xorl %eax,%eax
movl %eax,PCB_ONFAULT(%ecx)
ret
ALTENTRY(suibyte)
ENTRY(subyte)
movl _curpcb,%ecx
movl $fusufault,PCB_ONFAULT(%ecx)
movl 4(%esp),%edx
movb 8(%esp),%al
gs
movb %al,(%edx)
xorl %eax,%eax
movl %eax,PCB_ONFAULT(%ecx)
ret
#else /* USE_486_WRITE_PROTECT */
/*
* here starts the trouble again: check PTE, twice if word crosses
* a page boundary.
*/
# XXX - page boundary crossing is not handled yet
ALTENTRY(suibyte)
ENTRY(subyte)
movl _curpcb, %ecx
movl $fusufault, PCB_ONFAULT(%ecx)
movl 4(%esp), %edx
movl %edx, %eax
shrl $IDXSHIFT, %edx
andb $0xfc, %dl
movb _PTmap(%edx), %dl
andb $0x7, %dl /* must be VALID + USERACC + WRITE */
cmpb $0x7, %dl
je 1f
/* simulate a trap */
pushl %eax
call _trapwrite
popl %edx
orl %eax, %eax
jnz fusufault
1:
movl 4(%esp), %edx
movl 8(%esp), %eax
gs
movb %al, (%edx)
xorl %eax, %eax
movl _curpcb, %ecx
movl %eax, PCB_ONFAULT(%ecx)
ret
ENTRY(susword)
movl _curpcb, %ecx
movl $fusufault, PCB_ONFAULT(%ecx)
movl 4(%esp), %edx
movl %edx, %eax
shrl $IDXSHIFT, %edx
andb $0xfc, %dl
movb _PTmap(%edx), %dl
andb $0x7, %dl /* must be VALID + USERACC + WRITE */
cmpb $0x7, %dl
je 1f
/* simulate a trap */
pushl %eax
call _trapwrite
popl %edx
orl %eax, %eax
jnz fusufault
1:
movl 4(%esp), %edx
movl 8(%esp), %eax
gs
movw %ax, (%edx)
xorl %eax, %eax
movl _curpcb, %ecx
movl %eax, PCB_ONFAULT(%ecx)
ret
ALTENTRY(suiword)
ENTRY(suword)
movl _curpcb, %ecx
movl $fusufault, PCB_ONFAULT(%ecx)
movl 4(%esp), %edx
movl %edx, %eax
shrl $IDXSHIFT, %edx
andb $0xfc, %dl
movb _PTmap(%edx), %dl
andb $0x7, %dl /* must be VALID + USERACC + WRITE */
cmpb $0x7, %dl
je 1f
/* simulate a trap */
pushl %eax
call _trapwrite
popl %edx
orl %eax, %eax
jnz fusufault
1:
movl 4(%esp), %edx
movl 8(%esp), %eax
gs
movl %eax, 0(%edx)
xorl %eax, %eax
movl _curpcb, %ecx
movl %eax, PCB_ONFAULT(%ecx)
ret
#endif /* USE_486_WRITE_PROTECT */
/*
* copyoutstr(from, to, maxlen, int *lencopied)
* copy a string from from to to, stop when a 0 character is reached.
* return ENAMETOOLONG if string is longer than maxlen, and
* EFAULT on protection violations. If lencopied is non-zero,
* return the actual length in *lencopied.
*/
#ifdef USE_486_WRITE_PROTECT
ENTRY(copyoutstr)
pushl %esi
pushl %edi
movl _curpcb, %ecx
movl $cpystrflt, PCB_ONFAULT(%ecx)
movl 12(%esp), %esi # %esi = from
movl 16(%esp), %edi # %edi = to
movl 20(%esp), %edx # %edx = maxlen
incl %edx
1:
decl %edx
jz 4f
/*
* gs override doesn't work for stosb. Use the same explicit check
* as in copyout(). It's much slower now because it is per-char.
* XXX - however, it would be faster to rewrite this function to use
* strlen() and copyout().
*/
cmpl $VM_END_USER_ADDRESS, %edi
jae cpystrflt
lodsb
gs
stosb
orb %al,%al
jnz 1b
/* Success -- 0 byte reached */
decl %edx
xorl %eax, %eax
jmp 6f
4:
/* edx is zero -- return ENAMETOOLONG */
movl $ENAMETOOLONG, %eax
jmp 6f
#else /* ndef USE_486_WRITE_PROTECT */
ENTRY(copyoutstr)
pushl %esi
pushl %edi
movl _curpcb, %ecx
movl $cpystrflt, PCB_ONFAULT(%ecx)
movl 12(%esp), %esi # %esi = from
movl 16(%esp), %edi # %edi = to
movl 20(%esp), %edx # %edx = maxlen
1:
/*
* It suffices to check that the first byte is in user space, because
* we look at a page at a time and the end address is on a page
* boundary.
*/
cmpl $VM_END_USER_ADDRESS, %edi
jae cpystrflt
movl %edi, %eax
shrl $IDXSHIFT, %eax
andb $0xfc, %al
movb _PTmap(%eax), %al
andb $7, %al
cmpb $7, %al
je 2f
/* simulate trap */
pushl %edx
pushl %edi
call _trapwrite
popl %edi
popl %edx
orl %eax, %eax
jnz cpystrflt
2: /* copy up to end of this page */
movl %edi, %eax
andl $0x0fff, %eax
movl $NBPG, %ecx
subl %eax, %ecx /* ecx = NBPG - (src % NBPG) */
cmpl %ecx, %edx
jge 3f
movl %edx, %ecx /* ecx = min (ecx, edx) */
3:
orl %ecx, %ecx
jz 4f
decl %ecx
decl %edx
lodsb
stosb
orb %al, %al
jnz 3b
/* Success -- 0 byte reached */
decl %edx
xorl %eax, %eax
jmp 6f
4: /* next page */
orl %edx, %edx
jnz 1b
/* edx is zero -- return ENAMETOOLONG */
movl $ENAMETOOLONG, %eax
jmp 6f
#endif /* USE_486_WRITE_PROTECT */
/*
* copyinstr(from, to, maxlen, int *lencopied)
* copy a string from from to to, stop when a 0 character is reached.
* return ENAMETOOLONG if string is longer than maxlen, and
* EFAULT on protection violations. If lencopied is non-zero,
* return the actual length in *lencopied.
*/
ENTRY(copyinstr)
pushl %esi
pushl %edi
movl _curpcb, %ecx
movl $cpystrflt, PCB_ONFAULT(%ecx)
movl 12(%esp), %esi # %esi = from
movl 16(%esp), %edi # %edi = to
movl 20(%esp), %edx # %edx = maxlen
incl %edx
1:
decl %edx
jz 4f
gs
lodsb
stosb
orb %al,%al
jnz 1b
/* Success -- 0 byte reached */
decl %edx
xorl %eax, %eax
jmp 6f
4:
/* edx is zero -- return ENAMETOOLONG */
movl $ENAMETOOLONG, %eax
jmp 6f
cpystrflt:
movl $EFAULT, %eax
6: /* set *lencopied and return %eax */
movl _curpcb, %ecx
movl $0, PCB_ONFAULT(%ecx)
movl 20(%esp), %ecx
subl %edx, %ecx
movl 24(%esp), %edx
orl %edx, %edx
jz 7f
movl %ecx, (%edx)
7:
popl %edi
popl %esi
ret
/*
* copystr(from, to, maxlen, int *lencopied)
*/
ENTRY(copystr)
pushl %esi
pushl %edi
movl 12(%esp), %esi # %esi = from
movl 16(%esp), %edi # %edi = to
movl 20(%esp), %edx # %edx = maxlen
incl %edx
1:
decl %edx
jz 4f
lodsb
stosb
orb %al,%al
jnz 1b
/* Success -- 0 byte reached */
decl %edx
xorl %eax, %eax
jmp 6f
4:
/* edx is zero -- return ENAMETOOLONG */
movl $ENAMETOOLONG, %eax
6: /* set *lencopied and return %eax */
movl 20(%esp), %ecx
subl %edx, %ecx
movl 24(%esp), %edx
orl %edx, %edx
jz 7f
movl %ecx, (%edx)
7:
popl %edi
popl %esi
ret
/*****************************************************************************/
/* Handling of special 386 registers and descriptor tables etc */
/*****************************************************************************/
/*
* void lgdt(struct region_descriptor *rdp);
*/
ENTRY(lgdt)
/* reload the descriptor table */
movl 4(%esp),%eax
lgdt (%eax)
/* flush the prefetch q */
jmp 1f
nop
1:
/* reload "stale" selectors */
movl $KDSEL,%eax
movl %ax,%ds
movl %ax,%es
movl %ax,%ss
/* reload code selector by turning return into intersegmental return */
movl (%esp),%eax
pushl %eax
# movl $KCSEL,4(%esp)
movl $8,4(%esp)
lret
/*
* void lidt(struct region_descriptor *rdp);
*/
ENTRY(lidt)
movl 4(%esp),%eax
lidt (%eax)
ret
/*
* void lldt(u_short sel)
*/
ENTRY(lldt)
lldt 4(%esp)
ret
/*
* void ltr(u_short sel)
*/
ENTRY(ltr)
ltr 4(%esp)
ret
ENTRY(ssdtosd) # ssdtosd(*ssdp,*sdp)
pushl %ebx
movl 8(%esp),%ecx
movl 8(%ecx),%ebx
shll $16,%ebx
movl (%ecx),%edx
roll $16,%edx
movb %dh,%bl
movb %dl,%bh
rorl $8,%ebx
movl 4(%ecx),%eax
movw %ax,%dx
andl $0xf0000,%eax
orl %eax,%ebx
movl 12(%esp),%ecx
movl %edx,(%ecx)
movl %ebx,4(%ecx)
popl %ebx
ret
ENTRY(tlbflush) # tlbflush()
movl %cr3,%eax
orl $ I386_CR3PAT,%eax
movl %eax,%cr3
ret
ENTRY(load_cr0) # load_cr0(cr0)
movl 4(%esp),%eax
movl %eax,%cr0
ret
ENTRY(rcr0) # rcr0()
movl %cr0,%eax
ret
ENTRY(rcr2) # rcr2()
movl %cr2,%eax
ret
ENTRY(rcr3) # rcr3()
movl %cr3,%eax
ret
ENTRY(load_cr3) # void load_cr3(caddr_t cr3)
movl 4(%esp),%eax
orl $ I386_CR3PAT,%eax
movl %eax,%cr3
ret
/*****************************************************************************/
/* setjump, longjump */
/*****************************************************************************/
ENTRY(setjmp)
movl 4(%esp),%eax
movl %ebx, (%eax) # save ebx
movl %esp, 4(%eax) # save esp
movl %ebp, 8(%eax) # save ebp
movl %esi,12(%eax) # save esi
movl %edi,16(%eax) # save edi
movl (%esp),%edx # get rta
movl %edx,20(%eax) # save eip
xorl %eax,%eax # return (0);
ret
ENTRY(longjmp)
movl 4(%esp),%eax
movl (%eax),%ebx # restore ebx
movl 4(%eax),%esp # restore esp
movl 8(%eax),%ebp # restore ebp
movl 12(%eax),%esi # restore esi
movl 16(%eax),%edi # restore edi
movl 20(%eax),%edx # get rta
movl %edx,(%esp) # put in return frame
xorl %eax,%eax # return (1);
incl %eax
ret
/*****************************************************************************/
/* Scheduling */
/*****************************************************************************/
/*
* The following primitives manipulate the run queues.
* _whichqs tells which of the 32 queues _qs
* have processes in them. Setrq puts processes into queues, Remrq
* removes them from queues. The running process is on no queue,
* other processes are on a queue related to p->p_pri, divided by 4
* actually to shrink the 0-127 range of priorities into the 32 available
* queues.
*/
.globl _whichqs,_qs,_cnt,_panic
.comm _noproc,4
.comm _runrun,4
/*
* Setrq(p)
*
* Call should be made at spl6(), and p->p_stat should be SRUN
*/
ENTRY(setrq)
movl 4(%esp),%eax
cmpl $0,P_RLINK(%eax) # should not be on q already
je set1
pushl $set2
call _panic
set1:
movzbl P_PRI(%eax),%edx
shrl $2,%edx
btsl %edx,_whichqs # set q full bit
shll $3,%edx
addl $_qs,%edx # locate q hdr
movl %edx,P_LINK(%eax) # link process on tail of q
movl P_RLINK(%edx),%ecx
movl %ecx,P_RLINK(%eax)
movl %eax,P_RLINK(%edx)
movl %eax,P_LINK(%ecx)
ret
set2: .asciz "setrq"
/*
* Remrq(p)
*
* Call should be made at spl6().
*/
ENTRY(remrq)
movl 4(%esp),%eax
movzbl P_PRI(%eax),%edx
shrl $2,%edx
btrl %edx,_whichqs # clear full bit, panic if clear already
jb rem1
pushl $rem3
call _panic
rem1:
pushl %edx
movl P_LINK(%eax),%ecx # unlink process
movl P_RLINK(%eax),%edx
movl %edx,P_RLINK(%ecx)
movl P_RLINK(%eax),%ecx
movl P_LINK(%eax),%edx
movl %edx,P_LINK(%ecx)
popl %edx
movl $_qs,%ecx
shll $3,%edx
addl %edx,%ecx
cmpl P_LINK(%ecx),%ecx # q still has something?
je rem2
shrl $3,%edx # yes, set bit as still full
btsl %edx,_whichqs
rem2:
movl $0,P_RLINK(%eax) # zap reverse link to indicate off list
ret
rem3: .asciz "remrq"
sw0: .asciz "swtch"
/*
* When no processes are on the runq, Swtch branches to idle
* to wait for something to come ready.
*/
ALIGN_TEXT
Idle:
sti
SHOW_STI
ALIGN_TEXT
idle_loop:
call _spl0
cmpl $0,_whichqs
jne sw1
hlt # wait for interrupt
jmp idle_loop
badsw:
pushl $sw0
call _panic
/*NOTREACHED*/
/*
* Swtch()
*/
SUPERALIGN_TEXT /* so profiling doesn't lump Idle with swtch().. */
ENTRY(swtch)
incl _cnt+V_SWTCH
/* switch to new process. first, save context as needed */
movl _curproc,%ecx
/* if no process to save, don't bother */
testl %ecx,%ecx
je sw1
movl P_ADDR(%ecx),%ecx
movl (%esp),%eax # Hardware registers
movl %eax, PCB_EIP(%ecx)
movl %ebx, PCB_EBX(%ecx)
movl %esp, PCB_ESP(%ecx)
movl %ebp, PCB_EBP(%ecx)
movl %esi, PCB_ESI(%ecx)
movl %edi, PCB_EDI(%ecx)
#ifdef NPX
/* have we used fp, and need a save? */
mov _curproc,%eax
cmp %eax,_npxproc
jne 1f
pushl %ecx /* h/w bugs make saving complicated */
leal PCB_SAVEFPU(%ecx),%eax
pushl %eax
call _npxsave /* do it in a big C function */
popl %eax
popl %ecx
1:
#endif
movl _CMAP2,%eax # save temporary map PTE
movl %eax,PCB_CMAP2(%ecx) # in our context
movl $0,_curproc # out of process
# movw _cpl, %ax
# movw %ax, PCB_IML(%ecx) # save ipl
/* save is done, now choose a new process or idle */
sw1:
cli
SHOW_CLI
movl _whichqs,%edi
2:
# XXX - bsf is sloow
bsfl %edi,%eax # find a full q
je Idle # if none, idle
# XX update whichqs?
swfnd:
btrl %eax,%edi # clear q full status
jnb 2b # if it was clear, look for another
movl %eax,%ebx # save which one we are using
shll $3,%eax
addl $_qs,%eax # select q
movl %eax,%esi
#ifdef DIAGNOSTIC
cmpl P_LINK(%eax),%eax # linked to self? (e.g. not on list)
je badsw # not possible
#endif
movl P_LINK(%eax),%ecx # unlink from front of process q
movl P_LINK(%ecx),%edx
movl %edx,P_LINK(%eax)
movl P_RLINK(%ecx),%eax
movl %eax,P_RLINK(%edx)
cmpl P_LINK(%ecx),%esi # q empty
je 3f
btsl %ebx,%edi # nope, set to indicate full
3:
movl %edi,_whichqs # update q status
movl $0,%eax
movl %eax,_want_resched
#ifdef DIAGNOSTIC
cmpl %eax,P_WCHAN(%ecx)
jne badsw
cmpb $ SRUN,P_STAT(%ecx)
jne badsw
#endif
movl %eax,P_RLINK(%ecx) /* isolate process to run */
movl P_ADDR(%ecx),%edx
movl PCB_CR3(%edx),%ebx
/* switch address space */
movl %ebx,%cr3
/* restore context */
movl PCB_EBX(%edx), %ebx
movl PCB_ESP(%edx), %esp
movl PCB_EBP(%edx), %ebp
movl PCB_ESI(%edx), %esi
movl PCB_EDI(%edx), %edi
movl PCB_EIP(%edx), %eax
movl %eax, (%esp)
movl PCB_CMAP2(%edx),%eax # get temporary map
movl %eax,_CMAP2 # reload temporary map PTE
movl %ecx,_curproc # into next process
movl %edx,_curpcb
pushl %edx # save p to return
/*
* XXX - 0.0 forgot to save it - is that why this was commented out in 0.1?
* I think restoring the cpl is unnecessary, but we must turn off the cli
* now that spl*() don't do it as a side affect.
*/
pushl PCB_IML(%edx)
sti
SHOW_STI
#if 0
call _splx
#endif
addl $4,%esp
/*
* XXX - 0.0 gets here via swtch_to_inactive(). I think 0.1 gets here in the
* same way. Better return a value.
*/
popl %eax # return (p);
ret
ENTRY(mvesp)
movl %esp,%eax
ret
/*
* struct proc *swtch_to_inactive(p) ; struct proc *p;
*
* At exit of a process, move off the address space of the
* process and onto a "safe" one. Then, on a temporary stack
* return and run code that disposes of the old state.
* Since this code requires a parameter from the "old" stack,
* pass it back as a return value.
*/
ENTRY(swtch_to_inactive)
popl %edx # old pc
popl %eax # arg, our return value
movl _IdlePTD,%ecx
movl %ecx,%cr3 # good bye address space
#write buffer?
movl $tmpstk-4,%esp # temporary stack, compensated for call
jmp %edx # return, execute remainder of cleanup
/*
* savectx(pcb, altreturn)
* Update pcb, saving current processor state and arranging
* for alternate return ala longjmp in swtch if altreturn is true.
*/
ENTRY(savectx)
movl 4(%esp), %ecx
movw _cpl, %ax
movw %ax, PCB_IML(%ecx)
movl (%esp), %eax
movl %eax, PCB_EIP(%ecx)
movl %ebx, PCB_EBX(%ecx)
movl %esp, PCB_ESP(%ecx)
movl %ebp, PCB_EBP(%ecx)
movl %esi, PCB_ESI(%ecx)
movl %edi, PCB_EDI(%ecx)
#ifdef NPX
/*
* If npxproc == NULL, then the npx h/w state is irrelevant and the
* state had better already be in the pcb. This is true for forks
* but not for dumps (the old book-keeping with FP flags in the pcb
* always lost for dumps because the dump pcb has 0 flags).
*
* If npxproc != NULL, then we have to save the npx h/w state to
* npxproc's pcb and copy it to the requested pcb, or save to the
* requested pcb and reload. Copying is easier because we would
* have to handle h/w bugs for reloading. We used to lose the
* parent's npx state for forks by forgetting to reload.
*/
mov _npxproc,%eax
testl %eax,%eax
je 1f
pushl %ecx
movl P_ADDR(%eax),%eax
leal PCB_SAVEFPU(%eax),%eax
pushl %eax
pushl %eax
call _npxsave
popl %eax
popl %eax
popl %ecx
pushl %ecx
pushl $108+8*2 /* XXX h/w state size + padding */
leal PCB_SAVEFPU(%ecx),%ecx
pushl %ecx
pushl %eax
call _bcopy
addl $12,%esp
popl %ecx
1:
#endif
movl _CMAP2, %edx # save temporary map PTE
movl %edx, PCB_CMAP2(%ecx) # in our context
cmpl $0, 8(%esp)
je 1f
movl %esp, %edx # relocate current sp relative to pcb
subl $_kstack, %edx # (sp is relative to kstack):
addl %edx, %ecx # pcb += sp - kstack;
movl %eax, (%ecx) # write return pc at (relocated) sp@
# this mess deals with replicating register state gcc hides
movl 12(%esp),%eax
movl %eax,12(%ecx)
movl 16(%esp),%eax
movl %eax,16(%ecx)
movl 20(%esp),%eax
movl %eax,20(%ecx)
movl 24(%esp),%eax
movl %eax,24(%ecx)
1:
xorl %eax, %eax # return 0
ret
/*
* addupc(int pc, struct uprof *up, int ticks):
* update profiling information for the user process.
*/
ENTRY(addupc)
pushl %ebp
movl %esp,%ebp
movl 12(%ebp),%edx /* up */
movl 8(%ebp),%eax /* pc */
subl PR_OFF(%edx),%eax /* pc -= up->pr_off */
jl L1 /* if (pc < 0) return */
shrl $1,%eax /* praddr = pc >> 1 */
imull PR_SCALE(%edx),%eax /* praddr *= up->pr_scale */
shrl $15,%eax /* praddr = praddr << 15 */
andl $-2,%eax /* praddr &= ~1 */
cmpl PR_SIZE(%edx),%eax /* if (praddr > up->pr_size) return */
ja L1
/* addl %eax,%eax /* praddr -> word offset */
addl PR_BASE(%edx),%eax /* praddr += up-> pr_base */
movl 16(%ebp),%ecx /* ticks */
movl _curpcb,%edx
movl $proffault,PCB_ONFAULT(%edx)
addl %ecx,(%eax) /* storage location += ticks */
movl $0,PCB_ONFAULT(%edx)
L1:
leave
ret
ALIGN_TEXT
proffault:
/* if we get a fault, then kill profiling all together */
movl $0,PCB_ONFAULT(%edx) /* squish the fault handler */
movl 12(%ebp),%ecx
movl $0,PR_SCALE(%ecx) /* up->pr_scale = 0 */
leave
ret
# To be done:
ENTRY(astoff)
ret
/*****************************************************************************/
/* Trap handling */
/*****************************************************************************/
/*
* Trap and fault vector routines
*
* XXX - debugger traps are now interrupt gates so at least bdb doesn't lose
* control. The sti's give the standard losing behaviour for ddb and kgdb.
*/
#define IDTVEC(name) ALIGN_TEXT; .globl _X/**/name; _X/**/name:
#define TRAP(a) pushl $(a) ; jmp alltraps
#ifdef KGDB
# define BPTTRAP(a) sti; pushl $(a) ; jmp bpttraps
#else
# define BPTTRAP(a) sti; TRAP(a)
#endif
IDTVEC(div)
pushl $0; TRAP(T_DIVIDE)
IDTVEC(dbg)
#ifdef BDBTRAP
BDBTRAP(dbg)
#endif
pushl $0; BPTTRAP(T_TRCTRAP)
IDTVEC(nmi)
pushl $0; TRAP(T_NMI)
IDTVEC(bpt)
#ifdef BDBTRAP
BDBTRAP(bpt)
#endif
pushl $0; BPTTRAP(T_BPTFLT)
IDTVEC(ofl)
pushl $0; TRAP(T_OFLOW)
IDTVEC(bnd)
pushl $0; TRAP(T_BOUND)
IDTVEC(ill)
pushl $0; TRAP(T_PRIVINFLT)
IDTVEC(dna)
pushl $0; TRAP(T_DNA)
IDTVEC(dble)
TRAP(T_DOUBLEFLT)
/*PANIC("Double Fault");*/
IDTVEC(fpusegm)
pushl $0; TRAP(T_FPOPFLT)
IDTVEC(tss)
TRAP(T_TSSFLT)
/*PANIC("TSS not valid");*/
IDTVEC(missing)
TRAP(T_SEGNPFLT)
IDTVEC(stk)
TRAP(T_STKFLT)
IDTVEC(prot)
TRAP(T_PROTFLT)
IDTVEC(page)
TRAP(T_PAGEFLT)
IDTVEC(rsvd)
pushl $0; TRAP(T_RESERVED)
IDTVEC(fpu)
#ifdef NPX
/*
* Handle like an interrupt so that we can call npxintr to clear the
* error. It would be better to handle npx interrupts as traps but
* this is difficult for nested interrupts.
*/
pushl $0 /* dummy error code */
pushl $T_ASTFLT
pushal
nop /* silly, the bug is for popal and it only
* bites when the next instruction has a
* complicated address mode */
pushl %ds
pushl %es /* now the stack frame is a trap frame */
movl $KDSEL,%eax
movl %ax,%ds
movl %ax,%es
pushl _cpl
pushl $0 /* dummy unit to finish building intr frame */
incl _cnt+V_TRAP
call _npxintr
jmp doreti
#else
pushl $0; TRAP(T_ARITHTRAP)
#endif
/* 17 - 31 reserved for future exp */
IDTVEC(rsvd0)
pushl $0; TRAP(17)
IDTVEC(rsvd1)
pushl $0; TRAP(18)
IDTVEC(rsvd2)
pushl $0; TRAP(19)
IDTVEC(rsvd3)
pushl $0; TRAP(20)
IDTVEC(rsvd4)
pushl $0; TRAP(21)
IDTVEC(rsvd5)
pushl $0; TRAP(22)
IDTVEC(rsvd6)
pushl $0; TRAP(23)
IDTVEC(rsvd7)
pushl $0; TRAP(24)
IDTVEC(rsvd8)
pushl $0; TRAP(25)
IDTVEC(rsvd9)
pushl $0; TRAP(26)
IDTVEC(rsvd10)
pushl $0; TRAP(27)
IDTVEC(rsvd11)
pushl $0; TRAP(28)
IDTVEC(rsvd12)
pushl $0; TRAP(29)
IDTVEC(rsvd13)
pushl $0; TRAP(30)
IDTVEC(rsvd14)
pushl $0; TRAP(31)
SUPERALIGN_TEXT
alltraps:
pushal
nop
pushl %ds
pushl %es
movl $KDSEL,%eax
movl %ax,%ds
movl %ax,%es
calltrap:
incl _cnt+V_TRAP
call _trap
/*
* Return through doreti to handle ASTs. Have to change trap frame
* to interrupt frame.
*/
movl $T_ASTFLT,4+4+32(%esp) /* new trap type (err code not used) */
pushl _cpl
pushl $0 /* dummy unit */
jmp doreti
#ifdef KGDB
/*
* This code checks for a kgdb trap, then falls through
* to the regular trap code.
*/
SUPERALIGN_TEXT
bpttraps:
pushal
nop
pushl %es
pushl %ds
movl $KDSEL,%eax
movl %ax,%ds
movl %ax,%es
testb $SEL_RPL_MASK,TRAPF_CS_OFF(%esp)
# non-kernel mode?
jne calltrap # yes
call _kgdb_trap_glue
jmp calltrap
#endif
/*
* Call gate entry for syscall
*/
SUPERALIGN_TEXT
IDTVEC(syscall)
pushfl # only for stupid carry bit and more stupid wait3 cc kludge
# XXX - also for direction flag (bzero, etc. clear it)
pushal # only need eax,ecx,edx - trap resaves others
nop
movl $KDSEL,%eax # switch to kernel segments
movl %ax,%ds
movl %ax,%es
incl _cnt+V_SYSCALL # kml 3/25/93
call _syscall
/*
* Return through doreti to handle ASTs. Have to change syscall frame
* to interrupt frame.
*
* XXX - we should have set up the frame earlier to avoid the
* following popal/pushal (not much can be done to avoid shuffling
* the flags). Consistent frames would simplify things all over.
*/
movl 32+0(%esp),%eax /* old flags, shuffle to above cs:eip */
movl 32+4(%esp),%ebx /* `int' frame should have been ef, eip, cs */
movl 32+8(%esp),%ecx
movl %ebx,32+0(%esp)
movl %ecx,32+4(%esp)
movl %eax,32+8(%esp)
popal
nop
pushl $0 /* dummy error code */
pushl $T_ASTFLT
pushal
nop
movl __udatasel,%eax /* switch back to user segments */
pushl %eax /* XXX - better to preserve originals? */
pushl %eax
pushl _cpl
pushl $0
jmp doreti
/*****************************************************************************/
/* include generated interrupt vectors and ISA intr code */
/*****************************************************************************/
#include "i386/isa/vector.s"
#include "i386/isa/icu.s"