1/*
2 * Segment:offset types and macros
3 *
4 * Initially written by Michael Brown (mcb30).
5 */
6
7#ifndef SEGOFF_H
8#define SEGOFF_H
9
10#include <stdint.h>
11#include <io.h>
12
13/* Segment:offset structure.  Note that the order within the structure
14 * is offset:segment.
15 */
16typedef struct {
17	uint16_t offset;
18	uint16_t segment;
19} segoff_t;
20
21/* For PXE stuff */
22typedef segoff_t SEGOFF16_t;
23
24/* Macros for converting from virtual to segment:offset addresses,
25 * when we don't actually care which of the many isomorphic results we
26 * get.
27 */
28#ifdef DEBUG_SEGMENT
29uint16_t SEGMENT ( const void * const ptr ) {
30	uint32_t phys = virt_to_phys ( ptr );
31	if ( phys > 0xfffff ) {
32		printf ( "FATAL ERROR: segment address out of range\n" );
33	}
34	return phys >> 4;
35}
36#else
37#define SEGMENT(x) ( virt_to_phys ( x ) >> 4 )
38#endif
39#define OFFSET(x) ( virt_to_phys ( x ) & 0xf )
40#define SEGOFF(x) { OFFSET(x), SEGMENT(x) }
41#define VIRTUAL(x,y) ( phys_to_virt ( ( ( x ) << 4 ) + ( y ) ) )
42
43#endif /* SEGOFF_H */
44