diff options
Diffstat (limited to 'src/biosvar.h')
| -rw-r--r-- | src/biosvar.h | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/src/biosvar.h b/src/biosvar.h new file mode 100644 index 0000000..8b15f5b --- /dev/null +++ b/src/biosvar.h @@ -0,0 +1,184 @@ +// 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. + +#include "types.h" // u8 +#include "farptr.h" // SET_SEG + + +/**************************************************************** + * 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_com1, port_com2, port_com3, port_com4; + u16 port_lpt1, port_lpt2, port_lpt3; + u16 ebda_seg; + // 40:10 + u16 equipment_list_flags; + u8 pad1; + u16 mem_size_kb; + u8 pad2; + u8 ps2_ctrl_flag; + u16 kbd_flag; + 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[0x0f]; + // 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; +} __attribute__((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) ({ \ + SET_SEG(ES, 0x0000); \ + GET_VAR(ES, ((struct bios_data_area_s *)0)->var); }) +#define SET_BDA(var, val) do { \ + SET_SEG(ES, 0x0000); \ + SET_VAR(ES, ((struct bios_data_area_s *)0)->var, val); \ + } while (0) +#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) + + +/**************************************************************** + * Extended Bios Data Area (EBDA) + ****************************************************************/ + +struct extended_bios_data_area_s { + u8 size; + u8 other1[0x3c]; + + // FDPT - Can be splitted in data members if needed + u8 fdpt0[0x10]; + u8 fdpt1[0x10]; + + u8 other2[0xC4]; + + // ATA Driver data + //ata_t ata; + +#if BX_ELTORITO_BOOT + // El Torito Emulation data + cdemu_t cdemu; +#endif // BX_ELTORITO_BOOT +}; + + +/**************************************************************** + * Extended Bios Data Area (EBDA) + ****************************************************************/ + +#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_CF (1<<9) + +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 EBDA_SIZE 1 // In KiB +#define BASE_MEM_IN_K (640 - EBDA_SIZE) |