segoff.h revision 1b8adde7ba7d5e04395c141c5400dc2cffd7d809
/*
* Segment:offset types and macros
*
* Initially written by Michael Brown (mcb30).
*/
#ifndef SEGOFF_H
#define SEGOFF_H
#include <stdint.h>
#include <io.h>
/* Segment:offset structure. Note that the order within the structure
* is offset:segment.
*/
typedef struct {
uint16_t offset;
uint16_t segment;
} segoff_t;
/* For PXE stuff */
typedef segoff_t SEGOFF16_t;
/* Macros for converting from virtual to segment:offset addresses,
* when we don't actually care which of the many isomorphic results we
* get.
*/
#ifdef DEBUG_SEGMENT
uint16_t SEGMENT ( const void * const ptr ) {
uint32_t phys = virt_to_phys ( ptr );
if ( phys > 0xfffff ) {
printf ( "FATAL ERROR: segment address out of range\n" );
}
return phys >> 4;
}
#else
#define SEGMENT(x) ( virt_to_phys ( x ) >> 4 )
#endif
#define OFFSET(x) ( virt_to_phys ( x ) & 0xf )
#define SEGOFF(x) { OFFSET(x), SEGMENT(x) }
#define VIRTUAL(x,y) ( phys_to_virt ( ( ( x ) << 4 ) + ( y ) ) )
#endif /* SEGOFF_H */