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// Variable layouts of bios.
//
// Copyright (C) 2008 Kevin O'Connor <kevin@koconnor.net>
//
// This file may be distributed under the terms of the GNU GPLv3 license.
#ifndef __BIOSVAR_H
#define __BIOSVAR_H
#include "types.h" // u8
#include "farptr.h" // SET_SEG
#include "config.h" // CONFIG_*
#define PACKED __attribute__((packed))
/****************************************************************
* Bios Data Area (BDA)
****************************************************************/
struct ivec {
u16 offset;
u16 seg;
};
struct bios_data_area_s {
// 00:00
struct ivec ivecs[256];
// 30:00
// u8 stack[256];
// 40:00
u16 port_com[4];
u16 port_lpt[3];
u16 ebda_seg;
// 40:10
u16 equipment_list_flags;
u8 pad1;
u16 mem_size_kb;
u8 pad2;
u8 ps2_ctrl_flag;
u8 kbd_flag0;
u8 kbd_flag1;
u8 alt_keypad;
u16 kbd_buf_head;
u16 kbd_buf_tail;
// 40:1e
u8 kbd_buf[32];
u8 floppy_recalibration_status;
u8 floppy_motor_status;
// 40:40
u8 floppy_motor_counter;
u8 floppy_last_status;
u8 floppy_return_status[7];
u8 other1[0x7];
// 40:50
u8 other2[0x1c];
// 40:6c
u32 timer_counter;
// 40:70
u8 timer_rollover;
u8 other4[0x04];
u8 disk_count;
u8 disk_control_byte;
u8 port_disk;
u8 lpt_timeout[4];
u8 com_timeout[4];
// 40:80
u16 kbd_buf_start_offset;
u16 kbd_buf_end_offset;
u8 other5[7];
u8 floppy_last_data_rate;
u8 other6[3];
u8 floppy_harddisk_info;
// 40:90
u8 floppy_media_state[4];
u8 floppy_track0;
u8 floppy_track1;
u8 kbd_mode;
u8 kbd_led;
u32 ptr_user_wait_complete_flag;
u32 user_wait_timeout;
// 40:A0
u8 rtc_wait_flag;
} PACKED;
// BDA floppy_recalibration_status bitdefs
#define FRS_TIMEOUT (1<<7)
// BDA rtc_wait_flag bitdefs
#define RWS_WAIT_PENDING (1<<0)
#define RWS_WAIT_ELAPSED (1<<7)
// BDA floppy_media_state bitdefs
#define FMS_DRIVE_STATE_MASK (0x07)
#define FMS_MEDIA_DRIVE_ESTABLISHED (1<<4)
#define FMS_DOUBLE_STEPPING (1<<5)
#define FMS_DATA_RATE_MASK (0xc0)
// Accessor functions
#define GET_BDA(var) \
GET_FARVAR(0x0000, ((struct bios_data_area_s *)0)->var)
#define SET_BDA(var, val) \
SET_FARVAR(0x0000, ((struct bios_data_area_s *)0)->var, (val))
#define CLEARBITS_BDA(var, val) do { \
typeof(((struct bios_data_area_s *)0)->var) __val = GET_BDA(var); \
SET_BDA(var, (__val & ~(val))); \
} while (0)
#define SETBITS_BDA(var, val) do { \
typeof(((struct bios_data_area_s *)0)->var) __val = GET_BDA(var); \
SET_BDA(var, (__val | (val))); \
} while (0)
/****************************************************************
* Hard drive info
****************************************************************/
struct fdpt_s {
u16 cylinders;
u8 heads;
u8 a0h_signature;
u8 phys_sectors;
u16 precompensation;
u8 reserved;
u8 drive_control_byte;
u16 phys_cylinders;
u8 phys_heads;
u16 landing_zone;
u8 sectors;
u8 checksum;
} PACKED;
struct chs_s {
u16 heads; // # heads
u16 cylinders; // # cylinders
u16 spt; // # sectors / track
};
// DPTE definition
struct dpte_s {
u16 iobase1;
u16 iobase2;
u8 prefix;
u8 unused;
u8 irq;
u8 blkcount;
u8 dma;
u8 pio;
u16 options;
u16 reserved;
u8 revision;
u8 checksum;
};
struct ata_channel_s {
u8 iface; // ISA or PCI
u16 iobase1; // IO Base 1
u16 iobase2; // IO Base 2
u8 irq; // IRQ
} PACKED;
struct ata_device_s {
u8 type; // Detected type of ata (ata/atapi/none/unknown)
u8 device; // Detected type of attached devices (hd/cd/none)
u8 removable; // Removable device flag
u8 lock; // Locks for removable devices
u8 mode; // transfer mode : PIO 16/32 bits - IRQ - ISADMA - PCIDMA
u16 blksize; // block size
u8 translation; // type of translation
struct chs_s lchs; // Logical CHS
struct chs_s pchs; // Physical CHS
u32 sectors; // Total sectors count
} PACKED;
struct ata_s {
// ATA channels info
struct ata_channel_s channels[CONFIG_MAX_ATA_INTERFACES];
// ATA devices info
struct ata_device_s devices[CONFIG_MAX_ATA_DEVICES];
//
// map between (bios hd id - 0x80) and ata channels
u8 hdcount, hdidmap[CONFIG_MAX_ATA_DEVICES];
// map between (bios cd id - 0xE0) and ata channels
u8 cdcount, cdidmap[CONFIG_MAX_ATA_DEVICES];
// Buffer for DPTE table
struct dpte_s dpte;
// Count of transferred sectors and bytes
u16 trsfsectors;
u32 trsfbytes;
} PACKED;
// ElTorito Device Emulation data
struct cdemu_s {
u8 active;
u8 media;
u8 emulated_drive;
u8 controller_index;
u16 device_spec;
u32 ilba;
u16 buffer_segment;
u16 load_segment;
u16 sector_count;
// Virtual device
struct chs_s vdevice;
} PACKED;
/****************************************************************
* Extended Bios Data Area (EBDA)
****************************************************************/
struct extended_bios_data_area_s {
u8 size;
u8 other1[0x3c];
struct fdpt_s fdpt0;
struct fdpt_s fdpt1;
u8 other2[0xC4];
// ATA Driver data
struct ata_s ata;
// El Torito Emulation data
struct cdemu_s cdemu;
};
// Accessor functions
#define GET_EBDA(var) \
GET_FARVAR(EBDA_SEG, ((struct extended_bios_data_area_s *)0)->var)
#define SET_EBDA(var, val) \
SET_FARVAR(EBDA_SEG, ((struct extended_bios_data_area_s *)0)->var, (val))
/****************************************************************
* Initial Program Load (IPL)
****************************************************************/
// XXX - is this a standard, or just a bochs bios thing?
struct ipl_entry_s {
u16 type;
u16 flags;
u32 vector;
u32 description;
u32 reserved;
};
struct ipl_s {
struct ipl_entry_s table[8];
u16 count;
u16 sequence;
u8 pad[124];
};
#define IPL_TYPE_FLOPPY 0x01
#define IPL_TYPE_HARDDISK 0x02
#define IPL_TYPE_CDROM 0x03
#define IPL_TYPE_BEV 0x80
// Accessor functions
#define GET_IPL(var) \
GET_FARVAR(IPL_SEG, ((struct ipl_s *)0)->var)
#define SET_IPL(var, val) \
SET_FARVAR(IPL_SEG, ((struct ipl_s *)0)->var, (val))
/****************************************************************
* Registers saved/restored in romlayout.S
****************************************************************/
#define UREG(ER, R, RH, RL) union { u32 ER; struct { u16 R; u16 R ## _hi; }; struct { u8 RL; u8 RH; u8 R ## _hilo; u8 R ## _hihi; }; }
struct bregs {
u16 ds;
u16 es;
UREG(edi, di, di_hi, di_lo);
UREG(esi, si, si_hi, si_lo);
UREG(ebp, bp, bp_hi, bp_lo);
UREG(esp, sp, sp_hi, sp_lo);
UREG(ebx, bx, bh, bl);
UREG(edx, dx, dh, dl);
UREG(ecx, cx, ch, cl);
UREG(eax, ax, ah, al);
u16 ip;
u16 cs;
u16 flags;
} __attribute__((packed));
// bregs flags bitdefs
#define F_ZF (1<<6)
#define F_CF (1<<0)
static inline void
set_cf(struct bregs *regs, int cond)
{
if (cond)
regs->flags |= F_CF;
else
regs->flags &= ~F_CF;
}
/****************************************************************
* Bios Config Table
****************************************************************/
struct bios_config_table_s {
// XXX
u8 x;
};
extern struct bios_config_table_s BIOS_CONFIG_TABLE;
/****************************************************************
* Memory layout info
****************************************************************/
#define SEG_BIOS 0xf000
#define EBDA_SEG 0x9FC0
#define IPL_SEG 0x9FF0
#define EBDA_SIZE 1 // In KiB
#define BASE_MEM_IN_K (640 - EBDA_SIZE)
#endif // __BIOSVAR_H