/*
** @file	bios.h
**
** @author	Warren R. Carithers
**
** BIOS-related declarations
*/

#ifndef BIOS_H_
#define BIOS_H_

/*
** BIOS-related memory addresses
*/
#define BIOS_BDA 0x0400

/*
** Selected BIOS interrupt numbers
*/
#define BIOS_TIMER 0x08
#define BIOS_KBD 0x09
#define BIOS_VIDEO 0x10
#define BIOS_EQUIP 0x11
#define BIOS_MSIZ 0x12
#define BIOS_DISK 0x13
#define BIOS_SERIAL 0x14
#define BIOS_MISC 0x15
#define BIOS_KBDSVC 0x16
#define BIOS_PRTSVC 0x17
#define BIOS_BOOT 0x19
#define BIOS_RTCPCI 0x1a

// BIOS video commands (AH)
#define BV_W_ADV 0x0e

// BIOS disk commands (AH)
#define BD_RESET 0x00
#define BD_CHECK 0x01
#define BD_RDSECT 0x02
#define BD_WRSECT 0x03
#define BD_PARAMS 0x08

// BIOS disk commands with parameters (AX)
#define BD_READ(n) ((BD_RDSECT << 8) | (n))
#define BD_READ1 0x0201

// CMOS ports (used for masking NMIs)
#define CMOS_ADDR 0x70
#define CMOS_DATA 0x71

// important related commands
#define NMI_ENABLE 0x00
#define NMI_DISABLE 0x80

/*
** Physical Memory Map Table (0000:2D00 - 0000:7c00)
**
** Primarily used with the BIOS_MISC interrupt
*/
#define MMAP_SEG 0x02D0
#define MMAP_DISP 0x0000
#define MMAP_ADDR ((MMAP_SEG << 4) + MMAP_DISP)
#define MMAP_SECTORS 0x0a

#define MMAP_ENT 24 /* bytes per entry */
#define MMAP_MAX_ENTS (BOOT_ADDR - MMAP_ADDR - 4) / 24

#define MMAP_CODE 0xE820 /* int 0x15 code */
#define MMAP_MAGIC_NUM 0x534D4150 /* for 0xE820 interrupt */

#endif