#ifndef LIBRM_H
#define LIBRM_H
/* Drag in protected-mode segment selector values */
#include "virtaddr.h"
#include "realmode.h"
#ifndef ASSEMBLY
#include "stddef.h"
#include "string.h"
/*
* Data structures and type definitions
*
*/
/* Access to variables in .data16 and .text16 */
extern char *data16;
extern char *text16;
#define __data16( variable ) \
__attribute__ (( section ( ".data16" ) )) \
_data16_ ## variable __asm__ ( #variable )
#define __data16_array( variable, array ) \
__attribute__ (( section ( ".data16" ) )) \
_data16_ ## variable array __asm__ ( #variable )
#define __bss16( variable ) \
__attribute__ (( section ( ".bss16" ) )) \
_data16_ ## variable __asm__ ( #variable )
#define __bss16_array( variable, array ) \
__attribute__ (( section ( ".bss16" ) )) \
_data16_ ## variable array __asm__ ( #variable )
#define __text16( variable ) \
__attribute__ (( section ( ".text16.data" ) )) \
_text16_ ## variable __asm__ ( #variable )
#define __text16_array( variable, array ) \
__attribute__ (( section ( ".text16.data" ) )) \
_text16_ ## variable array __asm__ ( #variable )
#define __use_data16( variable ) \
( * ( ( typeof ( _data16_ ## variable ) * ) \
& ( data16 [ ( size_t ) & ( _data16_ ## variable ) ] ) ) )
#define __use_text16( variable ) \
( * ( ( typeof ( _text16_ ## variable ) * ) \
& ( text16 [ ( size_t ) & ( _text16_ ## variable ) ] ) ) )
#define __from_data16( pointer ) \
( ( unsigned int ) \
( ( ( void * ) (pointer) ) - ( ( void * ) data16 ) ) )
#define __from_text16( pointer ) \
( ( unsigned int ) \
( ( ( void * ) (pointer) ) - ( ( void * ) text16 ) ) )
/* Variables in librm.S, present in the normal data segment */
extern uint16_t rm_sp;
extern uint16_t rm_ss;
extern uint16_t __data16 ( rm_cs );
#define rm_cs __use_data16 ( rm_cs )
extern uint16_t __text16 ( rm_ds );
#define rm_ds __use_text16 ( rm_ds )
/* Functions that librm expects to be able to link to. Included here
* so that the compiler will catch prototype mismatches.
*/
extern void gateA20_set ( void );
/*
* librm_mgmt: functions for manipulating base memory and executing
* real-mode code.
*
* Full API documentation for these functions is in realmode.h.
*
*/
/* Macro for obtaining a physical address from a segment:offset pair. */
#define VIRTUAL(x,y) ( phys_to_virt ( ( ( x ) << 4 ) + ( y ) ) )
/* Copy to/from base memory */
static inline __attribute__ (( always_inline )) void
copy_to_real_librm ( unsigned int dest_seg, unsigned int dest_off,
void *src, size_t n ) {
memcpy ( VIRTUAL ( dest_seg, dest_off ), src, n );
}
static inline __attribute__ (( always_inline )) void
copy_from_real_librm ( void *dest, unsigned int src_seg,
unsigned int src_off, size_t n ) {
memcpy ( dest, VIRTUAL ( src_seg, src_off ), n );
}
#define put_real_librm( var, dest_seg, dest_off ) \
do { \
* ( ( typeof(var) * ) VIRTUAL ( dest_seg, dest_off ) ) = var; \
} while ( 0 )
#define get_real_librm( var, src_seg, src_off ) \
do { \
var = * ( ( typeof(var) * ) VIRTUAL ( src_seg, src_off ) ); \
} while ( 0 )
#define copy_to_real copy_to_real_librm
#define copy_from_real copy_from_real_librm
#define put_real put_real_librm
#define get_real get_real_librm
/**
* A pointer to a user buffer
*
* Even though we could just use a void *, we use an intptr_t so that
* attempts to use normal pointers show up as compiler warnings. Such
* code is actually valid for librm, but not for libkir (i.e. under
* KEEP_IT_REAL), so it's good to have the warnings even under librm.
*/
typedef intptr_t userptr_t;
/**
* Add offset to user pointer
*
* @v ptr User pointer
* @v offset Offset
* @ret new_ptr New pointer value
*/
static inline __attribute__ (( always_inline )) userptr_t
userptr_add ( userptr_t ptr, off_t offset ) {
return ( ptr + offset );
}
/**
* Copy data to user buffer
*
* @v buffer User buffer
* @v offset Offset within user buffer
* @v src Source
* @v len Length
*/
static inline __attribute__ (( always_inline )) void
copy_to_user ( userptr_t buffer, off_t offset, const void *src, size_t len ) {
memcpy ( ( ( void * ) buffer + offset ), src, len );
}
/**
* Copy data from user buffer
*
* @v dest Destination
* @v buffer User buffer
* @v offset Offset within user buffer
* @v len Length
*/
static inline __attribute__ (( always_inline )) void
copy_from_user ( void *dest, userptr_t buffer, off_t offset, size_t len ) {
memcpy ( dest, ( ( void * ) buffer + offset ), len );
}
/**
* Copy data between user buffers
*
* @v dest Destination user buffer
* @v dest_off Offset within destination buffer
* @v src Source user buffer
* @v src_off Offset within source buffer
* @v len Length
*/
static inline __attribute__ (( always_inline )) void
memcpy_user ( userptr_t dest, off_t dest_off, userptr_t src, off_t src_off,
size_t len ) {
memcpy ( ( ( void * ) dest + dest_off ), ( ( void * ) src + src_off ),
len );
}
/**
* Copy data between user buffers, allowing for overlap
*
* @v dest Destination user buffer
* @v dest_off Offset within destination buffer
* @v src Source user buffer
* @v src_off Offset within source buffer
* @v len Length
*/
static inline __attribute__ (( always_inline )) void
memmove_user ( userptr_t dest, off_t dest_off, userptr_t src, off_t src_off,
size_t len ) {
memmove ( ( ( void * ) dest + dest_off ), ( ( void * ) src + src_off ),
len );
}
/**
* Fill user buffer with a constant byte
*
* @v buffer User buffer
* @v offset Offset within buffer
* @v c Constant byte with which to fill
* @v len Length
*/
static inline __attribute__ (( always_inline )) void
memset_user ( userptr_t buffer, off_t offset, int c, size_t len ) {
memset ( ( ( void * ) buffer + offset ), c, len );
}
/**
* Find length of NUL-terminated string in user buffer
*
* @v buffer User buffer
* @v offset Offset within buffer
* @ret len Length of string (excluding NUL)
*/
static inline __attribute__ (( always_inline )) size_t
strlen_user ( userptr_t buffer, off_t offset ) {
return strlen ( ( void * ) buffer + offset );
}
/**
* Find character in user buffer
*
* @v buffer User buffer
* @v offset Starting offset within buffer
* @v c Character to search for
* @v len Length of user buffer
* @ret offset Offset of character, or <0 if not found
*/
static inline __attribute__ (( always_inline )) off_t
memchr_user ( userptr_t buffer, off_t offset, int c, size_t len ) {
void *found;
found = memchr ( ( ( void * ) buffer + offset ), c, len );
return ( found ? ( found - ( void * ) buffer ) : -1 );
}
/**
* Convert virtual address to user buffer
*
* @v virtual Virtual address
* @ret buffer User buffer
*
* This constructs a user buffer from an ordinary pointer. Use it
* when you need to pass a pointer to an internal buffer to a function
* that expects a @c userptr_t.
*/
static inline __attribute__ (( always_inline )) userptr_t
virt_to_user ( void * virtual ) {
return ( ( intptr_t ) virtual );
}
/**
* Convert segment:offset address to user buffer
*
* @v segment Real-mode segment
* @v offset Real-mode offset
* @ret buffer User buffer
*/
static inline __attribute__ (( always_inline )) userptr_t
real_to_user ( unsigned int segment, unsigned int offset ) {
return virt_to_user ( VIRTUAL ( segment, offset ) );
}
/**
* Convert physical address to user buffer
*
* @v physical Physical address
* @ret buffer User buffer
*/
static inline __attribute__ (( always_inline )) userptr_t
phys_to_user ( physaddr_t physical ) {
return virt_to_user ( phys_to_virt ( physical ) );
}
/**
* Convert user buffer to physical address
*
* @v buffer User buffer
* @v offset Offset within user buffer
* @ret physical Physical address
*/
static inline __attribute__ (( always_inline )) physaddr_t
user_to_phys ( userptr_t buffer, off_t offset ) {
return virt_to_phys ( ( void * ) buffer + offset );
}
extern uint16_t copy_user_to_rm_stack ( userptr_t data, size_t size );
extern void remove_user_from_rm_stack ( userptr_t data, size_t size );
/* TEXT16_CODE: declare a fragment of code that resides in .text16 */
#define TEXT16_CODE( asm_code_str ) \
".section \".text16\", \"ax\", @progbits\n\t" \
".code16\n\t" \
asm_code_str "\n\t" \
".code32\n\t" \
".previous\n\t"
/* REAL_CODE: declare a fragment of code that executes in real mode */
#define REAL_CODE( asm_code_str ) \
"pushl $1f\n\t" \
"call real_call\n\t" \
"addl $4, %%esp\n\t" \
TEXT16_CODE ( "\n1:\n\t" \
asm_code_str \
"\n\t" \
"ret\n\t" )
/* PHYS_CODE: declare a fragment of code that executes in flat physical mode */
#define PHYS_CODE( asm_code_str ) \
"call _virt_to_phys\n\t" \
asm_code_str \
"call _phys_to_virt\n\t"
#endif /* ASSEMBLY */
#endif /* LIBRM_H */
