vgasrc/vgabios.h

#ifndef __VGABIOS_H
#define __VGABIOS_H

#include "types.h" // u8
#include "farptr.h" // struct segoff_s

// standard BIOS Video Parameter Table
struct VideoParam_s {
    u8 twidth;
    u8 theightm1;
    u8 cheight;
    u16 slength;
    u8 sequ_regs[4];
    u8 miscreg;
    u8 crtc_regs[25];
    u8 actl_regs[20];
    u8 grdc_regs[9];
} PACKED;

extern struct VideoParam_s video_param_table[29];

struct saveBDAstate {
    u8 video_mode;
    u16 video_cols;
    u16 video_pagesize;
    u16 crtc_address;
    u8 video_rows;
    u16 char_height;
    u8 video_ctl;
    u8 video_switches;
    u8 modeset_ctl;
    u16 cursor_type;
    u16 cursor_pos[8];
    u16 video_pagestart;
    u8 video_page;
    /* current font */
    struct segoff_s font0;
    struct segoff_s font1;
};

// Mode flags
#define MF_GRAYSUM    0x0002
#define MF_NOPALETTE  0x0008
#define MF_CUSTOMCRTC 0x0800
#define MF_LINEARFB   0x4000
#define MF_NOCLEARMEM 0x8000

// Memory model types
#define MM_TEXT            0x00
#define MM_CGA             0x01
#define MM_HERCULES        0x02
#define MM_PLANAR          0x03
#define MM_PACKED          0x04
#define MM_NON_CHAIN_4_256 0x05
#define MM_DIRECT          0x06
#define MM_YUV             0x07

struct vgamode_s {
    u8 memmodel;
    u16 width;
    u16 height;
    u8 depth;
    u8 cwidth;
    u8 cheight;
    u16 sstart;
};

// vgafonts.c
extern u8 vgafont8[];
extern u8 vgafont14[];
extern u8 vgafont16[];
extern u8 vgafont14alt[];
extern u8 vgafont16alt[];

// vgabios.c
extern int VgaBDF;
#define SET_VGA(var, val) SET_FARVAR(get_global_seg(), (var), (val))
struct carattr {
    u8 car, attr, use_attr;
};
struct cursorpos {
    u8 x, y, page;
};
u16 calc_page_size(u8 memmodel, u16 width, u16 height);
struct vgamode_s *get_current_mode(void);
void modeswitch_set_bda(int mode, int flags, struct vgamode_s *vmode_g);

// vgafb.c
void vgafb_scroll(int nblines, int attr
                  , struct cursorpos ul, struct cursorpos lr);
void vgafb_write_char(struct cursorpos cp, struct carattr ca);
struct carattr vgafb_read_char(struct cursorpos cp);
void vgafb_write_pixel(u8 color, u16 x, u16 y);
u8 vgafb_read_pixel(u16 x, u16 y);

// vbe.c
u32 VBE_total_memory;
u32 VBE_capabilities;
u32 VBE_framebuffer;
u16 VBE_win_granularity;
#define VBE_OEM_STRING "SeaBIOS VBE(C) 2011"
#define VBE_VENDOR_STRING "SeaBIOS Developers"
#define VBE_PRODUCT_STRING "SeaBIOS VBE Adapter"
#define VBE_REVISION_STRING "Rev. 1"
struct bregs;
void handle_104f(struct bregs *regs);

#endif // vgabios.h