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/* Copyright (C) 1994 Free Software Foundation, Inc.
Contributed by Joel Sherrill (jsherril@redstone-emh2.army.mil),
On-Line Applications Research Corporation.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
/* i386.h
*
* This file contains macros which are used to access i80386
* registers which are not addressable by C. This file contains
* functions which are useful to those developing target
* specific support routines.
*/
#ifndef i386_h__
#define i386_h__
typedef unsigned char unsigned8;
typedef unsigned short unsigned16;
typedef unsigned int unsigned32;
#define disable_intr( isrlevel ) \
{ (isrlevel) = 0; \
asm volatile ( "pushf ; \
pop %0 ; \
cli " \
: "=r" ((isrlevel)) : "0" ((isrlevel)) ); \
}
#define enable_intr( isrlevel ) \
{ asm volatile ( "push %0 ; \
popf " \
: "=r" ((isrlevel)) : "0" ((isrlevel)) ); \
}
#define delay( _microseconds ) \
{ \
unsigned32 _counter; \
\
_counter = (_microseconds); \
\
asm volatile ( "0: nop;" \
" mov %0,%0 ;" \
" loop 0" : "=c" (_counter) \
: "0" (_counter) \
); \
\
}
/* segment access functions */
static inline unsigned16 get_cs()
{
register unsigned16 segment = 0;
asm volatile ( "movw %%cs,%0" : "=r" (segment) : "0" (segment) );
return segment;
}
static inline unsigned16 get_ds()
{
register unsigned16 segment = 0;
asm volatile ( "movw %%ds,%0" : "=r" (segment) : "0" (segment) );
return segment;
}
static inline unsigned16 get_es()
{
register unsigned16 segment = 0;
asm volatile ( "movw %%es,%0" : "=r" (segment) : "0" (segment) );
return segment;
}
static inline unsigned16 get_ss()
{
register unsigned16 segment = 0;
asm volatile ( "movw %%ss,%0" : "=r" (segment) : "0" (segment) );
return segment;
}
static inline unsigned16 get_fs()
{
register unsigned16 segment = 0;
asm volatile ( "movw %%fs,%0" : "=r" (segment) : "0" (segment) );
return segment;
}
static inline unsigned16 get_gs()
{
register unsigned16 segment = 0;
asm volatile ( "movw %%gs,%0" : "=r" (segment) : "0" (segment) );
return segment;
}
/* i80x86 I/O instructions */
#define outport_byte( _port, _value ) \
{ register unsigned16 __port = _port; \
register unsigned8 __value = _value; \
\
asm volatile ( "outb %0,%1" : "=a" (__value), "=d" (__port) \
: "0" (__value), "1" (__port) \
); \
}
#define outport_word( _port, _value ) \
{ register unsigned16 __port = _port; \
register unsigned16 __value = _value; \
\
asm volatile ( "outw %0,%1" : "=a" (__value), "=d" (__port) \
: "0" (__value), "1" (__port) \
); \
}
#define outport_long( _port, _value ) \
{ register unsigned16 __port = _port; \
register unsigned32 __value = _value; \
\
asm volatile ( "outl %0,%1" : "=a" (__value), "=d" (__port) \
: "0" (__value), "1" (__port) \
); \
}
#define inport_byte( _port, _value ) \
{ register unsigned16 __port = _port; \
register unsigned8 __value = 0; \
\
asm volatile ( "inb %1,%0" : "=a" (__value), "=d" (__port) \
: "0" (__value), "1" (__port) \
); \
_value = __value; \
}
#define inport_word( _port, _value ) \
{ register unsigned16 __port = _port; \
register unsigned16 __value = 0; \
\
asm volatile ( "inw %1,%0" : "=a" (__value), "=d" (__port) \
: "0" (__value), "1" (__port) \
); \
_value = __value; \
}
#define inport_long( _port, _value ) \
{ register unsigned16 __port = _port; \
register unsigned32 __value = 0; \
\
asm volatile ( "inl %1,%0" : "=a" (__value), "=d" (__port) \
: "0" (__value), "1" (__port) \
); \
_value = __value; \
}
/* structures */
/* See Chapter 5 - Memory Management in i386 manual */
struct GDT_slot {
unsigned16 limit_0_15;
unsigned16 base_0_15;
unsigned8 base_16_23;
unsigned8 type_dt_dpl_p;
unsigned8 limit_16_19_granularity;
unsigned8 base_24_31;
};
/* See Chapter 9 - Exceptions and Interrupts in i386 manual
*
* NOTE: This is the IDT entry for interrupt gates ONLY.
*/
struct IDT_slot {
unsigned16 offset_0_15;
unsigned16 segment_selector;
unsigned8 reserved;
unsigned8 p_dpl;
unsigned16 offset_16_31;
};
struct DTR_load_save_format {
unsigned16 limit;
unsigned32 physical_address;
};
/* variables */
extern struct IDT_slot Interrupt_descriptor_table[ 256 ];
extern struct GDT_slot Global_descriptor_table[ 8192 ];
/* functions */
#ifdef CPU_INITIALIZE
#define EXTERN
#else
#undef EXTERN
#define EXTERN extern
#endif
void *Logical_to_physical(
unsigned16 segment,
void *address
);
void *Physical_to_logical(
unsigned16 segment,
void *address
);
/* complicated static inline functions */
#define get_GDTR( _gdtr_address ) \
{ \
void *_gdtr = (_gdtr_address); \
\
asm volatile( "sgdt (%0)" : "=r" (_gdtr) : "0" (_gdtr) ); \
}
#define get_GDT_slot( _gdtr_base, _segment, _slot_address ) \
{ \
register unsigned32 _gdt_slot = (_gdtr_base) + (_segment); \
register volatile void *_slot = (_slot_address); \
register unsigned32 _temporary = 0; \
\
asm volatile( "movl %%gs:(%0),%1 ; \
movl %1,(%2) ; \
movl %%gs:4(%0),%1 ; \
movl %1,4(%2)" \
: "=r" (_gdt_slot), "=r" (_temporary), "=r" (_slot) \
: "0" (_gdt_slot), "1" (_temporary), "2" (_slot) \
); \
}
#define set_GDT_slot( _gdtr_base, _segment, _slot_address ) \
{ \
register unsigned32 _gdt_slot = (_gdtr_base) + (_segment); \
register volatile void *_slot = (_slot_address); \
register unsigned32 _temporary = 0; \
\
asm volatile( "movl (%2),%1 ; \
movl %1,%%gs:(%0) ; \
movl 4(%2),%1 ; \
movl %1,%%gs:4(%0) \
" \
: "=r" (_gdt_slot), "=r" (_temporary), "=r" (_slot) \
: "0" (_gdt_slot), "1" (_temporary), "2" (_slot) \
); \
}
static inline void set_segment(
unsigned16 segment,
unsigned32 base,
unsigned32 limit
)
{
struct DTR_load_save_format gdtr;
volatile struct GDT_slot Gdt_slot;
volatile struct GDT_slot *gdt_slot = &Gdt_slot;
unsigned16 tmp_segment = 0;
unsigned32 limit_adjusted;
/* load physical address of the GDT */
get_GDTR( &gdtr );
gdt_slot->type_dt_dpl_p = 0x92; /* present, dpl=0, */
/* application=1, */
/* type=data read/write */
gdt_slot->limit_16_19_granularity = 0x40; /* 32 bit segment */
limit_adjusted = limit;
if ( limit > 4095 ) {
gdt_slot->limit_16_19_granularity |= 0x80; /* set granularity bit */
limit_adjusted /= 4096;
}
gdt_slot->limit_16_19_granularity |= (limit_adjusted >> 16) & 0xff;
gdt_slot->limit_0_15 = limit_adjusted & 0xffff;
gdt_slot->base_0_15 = base & 0xffff;
gdt_slot->base_16_23 = (base >> 16) & 0xff;
gdt_slot->base_24_31 = (base >> 24);
set_GDT_slot( gdtr.physical_address, segment, gdt_slot );
/* Now, reload all segment registers so the limit takes effect. */
asm volatile( "movw %%ds,%0 ; movw %0,%%ds
movw %%es,%0 ; movw %0,%%es
movw %%fs,%0 ; movw %0,%%fs
movw %%gs,%0 ; movw %0,%%gs
movw %%ss,%0 ; movw %0,%%ss"
: "=r" (tmp_segment)
: "0" (tmp_segment)
);
}
#endif
/* end of include file */
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