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/* $OpenBSD: gidt.S,v 1.4 1997/04/18 01:28:02 mickey Exp $ */
/*
* Copyright (c) 1997 Michael Shalayeff
* All rights reserved.
*
* 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 Michael Shalayeff.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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.
*
*/
.file "gidt.S"
#include <machine/asm.h>
#include <machine/psl.h>
#define _LOCORE
#include <machine/segments.h>
#include <machine/specialreg.h>
#include <machine/trap.h>
#include <debug_md.h>
#undef _LOCORE
#define addr32 .byte 0x67
#define data32 .byte 0x66
.data
.globl _Gdtr
.align 3
gdt:
/* 0x00 : null */
.space 8
/* 0x08 : flat code */
.word 0xFFFF # lolimit
.word 0 # lobase
.byte 0 # midbase
.byte SDT_MEMERAC | 0 | 0x80 # RXAC, dpl = 0, present
.byte 0xf | 0 | 0x40 | 0x80 # hilimit, xx, 32bit, 4k granularity
.byte 0 # hibase
/* 0x10 : flat data */
.word 0xFFFF # lolimit
.word 0 # lobase
.byte 0 # midbase
.byte SDT_MEMRWA | 0 | 0x80 # RWA, dpl = 0, present
.byte 0xf | 0 | 0x40 | 0x80 # hilimit, xx, 32bit, 4k granularity
.byte 0 # hibase
/* 0x18 : 16 bit code */
.word 0xFFFF # lolimit
.word (START & 0xffff) # lobase
.byte (START >> 16) & 0xff # midbase
.byte SDT_MEMERA | 0 | 0x80 # RXAC, dpl = 0, present
.byte 0xf | 0 | 0 | 0 # hilimit, xx, 16bit, byte granularity
.byte (START >> 20) & 0xff # hibase
/* 0x20 : 16 bit data */
.word 0xFFFF # lolimit
.word (START & 0xffff) # lobase
.byte (START >> 16) & 0xff # midbase
.byte SDT_MEMRWA | 0 | 0x80 # RXAC, dpl = 0, present
.byte 0xf | 0 | 0 | 0 # hilimit, xx, 16bit, byte granularity
.byte (START >> 20) & 0xff # hibase
_Gdtr: .word . - gdt - 1
.long gdt
.word 0
.globl _Idtr_real
.align 3
_Idtr_real:
.word 1023
.long 0
.globl _Idtr_reset
.align 3
_Idtr_reset:
.word 0
.long 0
.globl _Idtr_prot
.align 3
idt:
.space 32*8, 0 /* internal (0-31) */
/* Maskable interrupts (32-255) */
.space 32*8, 0 /* BIOS entry points (32-63) */
.space 16*8, 0 /* DOS entry points (64-80) */
_Idtr_prot:
.word . - idt - 1
.long idt
.text
#define IPROC(n) X/**/n
#define IBIOS(n) IPROC(bios/**/n)
#define IDOS(n) IPROC(dos/**/n)
.globl idt_init
idt_init:
pushl %edi
movl $idt, %edi
#define fixe(p) \
movl $ IPROC(p), %eax; \
stosw; /* lo offset handler */ \
movw $0x8, (%edi); /* handler %cs */ \
incl %edi; incl %edi; \
incl %edi; /* reserved */ \
movb $(0x80|SDT_SYS386TGT), (%edi); /* 32bit trap gate */ \
incl %edi; \
shrl $16, %eax; \
stosw; /* hi offset handler */
fixe(de); fixe(db); fixe(nmi); fixe(bp); fixe(of); fixe(br)
fixe(ud); fixe(nm); fixe(df); fixe(fo); fixe(ts); fixe(np)
fixe(ss); fixe(gp); fixe(pf); fixe(xx); fixe(mf); fixe(ac)
fixe(mc)
fixe(xx); fixe(xx); fixe(xx); fixe(xx); fixe(xx); fixe(xx)
fixe(xx); fixe(xx); fixe(xx); fixe(xx); fixe(xx); fixe(xx)
fixe(xx)
#define fixb(b) fixe(bios/**/b)
fixb(0); fixb(1); fixb(2); fixb(3); fixb(4); fixb(5)
fixb(6); fixb(7); fixb(8); fixb(9); fixb(10); fixb(11)
fixb(12); fixb(13); fixb(14); fixb(15); fixb(16); fixb(17)
fixb(18); fixb(19); fixb(20); fixb(21); fixb(22); fixb(23)
fixb(24); fixb(25); fixb(26); fixb(27); fixb(28); fixb(29)
fixb(30); fixb(31)
#define fixd(d) fixe(dos/**/b)
popl %edi
ret
#define IENTRY(name,type) \
IPROC(name): \
pushl $type ; \
jmp 1f
#define IENTRY_ERR(name,err,type) \
IPROC(name): \
pushl $err ; \
pushl $type ; \
jmp 1f
IPROC(xx):
pushl $1
pushl $T_RESERVED
jmp 1f
IENTRY_ERR(de,0,T_DIVIDE) /* #DE divide by zero */
IENTRY_ERR(db,0,T_TRCTRAP) /* #DB debug */
IENTRY_ERR(nmi,0,T_NMI) /* NMI */
IENTRY_ERR(bp,0,T_BPTFLT) /* #BP breakpoint */
IENTRY_ERR(of,0,T_OFLOW) /* #OF overflow */
IENTRY_ERR(br,0,T_BOUND) /* #BR BOUND range exceeded */
IENTRY_ERR(ud,0,T_PRIVINFLT) /* #UD invalid opcode */
IENTRY_ERR(nm,0,T_DNA) /* #NM device not available */
IENTRY(df,T_DOUBLEFLT) /* #DF double fault */
IENTRY_ERR(fo,0,T_FPOPFLT) /* #FO coprocessor segment overrun */
IENTRY(ts,T_TSSFLT) /* #TS innvalid TSS */
IENTRY(np,T_SEGNPFLT) /* #NP segmant not present */
IENTRY(ss,T_STKFLT) /* #SS stack fault */
IENTRY(gp,T_PROTFLT) /* #GP general protection */
IENTRY(pf,T_PAGEFLT) /* #PF page fault */
IENTRY_ERR(mf,0,T_ARITHTRAP) /* #MF floating point error */
IENTRY(ac,T_ALIGNFLT) /* #AC alignment check */
IENTRY(mc,T_MACHK) /* #MC machine check */
.globl alltraps
1: /* save on jumps */
jmp alltraps
#define IBIOSENT(n) IBIOS(n): pushl $n; jmp BIOSh
IBIOSENT(0); IBIOSENT(1); IBIOSENT(2); IBIOSENT(3)
IBIOSENT(4); IBIOSENT(5); IBIOSENT(6); IBIOSENT(7)
IBIOSENT(8); IBIOSENT(9); IBIOSENT(10); IBIOSENT(11)
IBIOSENT(12); IBIOSENT(13); IBIOSENT(14); IBIOSENT(15)
IBIOSENT(16); IBIOSENT(17); IBIOSENT(18); IBIOSENT(19)
IBIOSENT(20); IBIOSENT(21); IBIOSENT(22); IBIOSENT(23)
IBIOSENT(24); IBIOSENT(25); IBIOSENT(26); IBIOSENT(27)
IBIOSENT(28); IBIOSENT(29); IBIOSENT(30); IBIOSENT(31)
/*
* entry point for BIOS real-mode interface
* all the magic for real-prot mode switching is here
*
* Call: %eax, %ecx, %edx, %ebx, %ebp, %esi, %ds, %di==real mode %es
* Return: %eax, %edx, %ecx, %eflags (as returned from BIOS)
*
*/
.globl BIOSh
BIOSh:
pushal
pushl %ds
pushl %es
/* save %eax */
movl %eax, 2f
/* save BIOS int vector */
movb 10*4(%esp), %al
movb %al, intno
/* setup 16bit labels in ljmps */
#ifdef GIDT_DEBUG
movl $0xb8000, %eax
movl $0x47314730, (%eax)
#endif
movl $0x20, %eax
# ljmp $0x18, $2f
.byte 0xea /* Change to 16bit mode */
.long 1f - START
.word 0x18
1:
movl %ax, %ds
#ifdef GIDT_DEBUG
data32
movl $(0xb8000 - START), %eax
data32
addr32
movl $0x4f314f30, (%eax)
#endif
movl %cr0, %eax /* disable prot mode memory management */
data32
andl $~CR0_PE, %eax
movl %eax, %cr0
# ljmp (START >> 16), $4f
.byte 0xea /* load real mode cs:ip */
.word 1f
.word (START >> 4)
1:
xorl %eax, %eax /* setup: %ds, %es, %ss */
movl %ax, %ds
movl %ax, %ss
movl %di, %es
#ifdef GIDT_DEBUG
data32
movl $0xb8004, %eax
data32
addr32
movl $0x47334732, (%eax)
#endif
addr32
data32
lidt _Idtr_real /* load idtr for DOS/BIOS operations */
data32
# movl Leax, %eax
.byte 0xb8
2: .long 0x90909090 /* restore %eax */
sti
int $0
intno = . - 1
movb %ah, %bh /* save flags to return to caller */
lahf
xchgb %ah, %bh
cli /* no maskable interrupts in prot mode */
addr32
data32
movl %eax, 2f /* save %eax */
#ifdef GIDT_DEBUG
data32
movl $0xb8004, %eax
data32
addr32
movl $0x4f334f32, (%eax)
#endif
addr32
data32
lgdt _C_LABEL(Gdtr) /* load the gdtr */
movl %cr0, %eax /* enable prot mode memory management */
data32
orl $CR0_PE, %eax
movl %eax, %cr0
data32
ljmp $0x08, $1f /* reload %cs, and flush pipeline */
1:
/* reload 32bit %ds, %ss, %es */
movl $0x10, %eax
movl %ax, %ds
movl %ax, %ss
#ifdef GIDT_DEBUG
movl $0xb8008, %eax
movl $0x47344733, (%eax)
#endif
/* load idtr for debugger and DOS/BIOS iface */
lidt _Idtr_prot
# movl Leax, %eax
.byte 0xb8
2: .long 0x90909090 /* eax */
/* pass BIOS return values back to caller */
movl %eax, 0x9*4(%esp)
movl %ecx, 0x8*4(%esp)
movl %edx, 0x7*4(%esp)
movb %bh , 0xd*4(%esp)
popl %es
popl %ds
popal
incl %esp; incl %esp; incl %esp; incl %esp
iret
|
