diff options
Diffstat (limited to 'int10vga.h')
| -rw-r--r-- | int10vga.h | 196 |
1 files changed, 169 insertions, 27 deletions
@@ -5,18 +5,6 @@ #define BIOS_DATA_AREA_SEGMENT 0x40 -// TODO Assuming screenwidth, videopage on ss rather than using far -static uint8_t int10_get_video_mode(uint8_t *screenwidth, uint8_t *videopage); -#pragma aux int10_get_video_mode = \ - "mov al, 0" \ - "mov ah, 0x0F" \ - "int 0x10" \ - "mov ss:[si], ah" \ - "mov ss:[di], bh" \ - __parm [si] [di] \ - __value [al] \ - __modify [ax bh] - static inline uint32_t bda_get_dword(unsigned int offset) { uint32_t __far *p = MK_FP(BIOS_DATA_AREA_SEGMENT, offset); return *p; @@ -43,29 +31,183 @@ static inline uint8_t bda_get_byte(unsigned int offset) { #define bda_get_tick_count() bda_get_dword(0x6c) #define bda_get_tick_count_lo() bda_get_word(0x6c) -static inline uint16_t __far * get_video_char(uint8_t page, unsigned int x, unsigned int y) -{ - return MK_FP(0xB800, (page * bda_get_video_page_size()) - + ((y * bda_get_num_columns()) + x) * 2); -} +enum videotype { + VIDEO_UNKNOWN, + VIDEO_TEXT, + VIDEO_CGA, + VIDEO_EGA, + VIDEO_VGA +}; + +struct modeinfo { + uint8_t mode; + uint8_t page; + enum videotype type; + + uint16_t pixels_width, pixels_height; + uint16_t bytes_per_line; + uint16_t odd_scanline_offset; + uint8_t bits_per_pixel; + uint8_t num_planes; -static inline uint8_t __far * get_video_scanline(uint8_t mode, uint8_t page, unsigned int y) + /** Pointer to video memory. */ + uint8_t __far * begin; +}; + +static void get_current_video_mode_info(struct modeinfo *info) { - switch (mode) { + uint16_t segment; + + info->mode = bda_get_video_mode() & ~0x80; + info->page = bda_get_cur_video_page(); + + info->odd_scanline_offset = 0; + + switch (info->mode) { + case 0: + case 1: + case 2: + case 3: // CGA text modes with 25 rows and variable columns + case 7: // MDA Mono text mode + info->type = VIDEO_TEXT; + info->pixels_width = bda_get_num_columns() * 8; + info->pixels_height = (bda_get_last_row()+1) * 8; + info->bytes_per_line = bda_get_num_columns() * 2; + info->bits_per_pixel = 2 * 8; + info->num_planes = 1; + segment = 0xB800; + break; + case 4: - case 5: - case 6: // CGA modes - // Scalines are 80 bytes long, however they are interleaved. - // Even numbered scanlines begin at 0, odd lines begin at 0x2000. - // So offset by y%2 * 0x2000. - return MK_FP(0xB800, (page * bda_get_video_page_size()) - + ((y/2) * 80) + (y%2) * 0x2000); + case 5: // CGA 320x200 4-color + info->type = VIDEO_CGA; + info->pixels_width = 320; + info->pixels_height = 200; + info->bytes_per_line = 80; + info->odd_scanline_offset = 0x2000; + info->bits_per_pixel = 2; + info->num_planes = 1; + segment = 0xB800; + break; + + case 6: // CGA 640x200 2-color + info->type = VIDEO_CGA; + info->pixels_width = 640; + info->pixels_height = 200; + info->bytes_per_line = 80; + info->odd_scanline_offset = 0x2000; + info->bits_per_pixel = 1; + info->num_planes = 1; + segment = 0xB800; + break; + + case 0xd: // EGA 320x200 16-color + info->type = VIDEO_EGA; + info->pixels_width = 320; + info->pixels_height = 200; + info->bytes_per_line = 40; + info->bits_per_pixel = 1; + info->num_planes = 4; + segment = 0xA000; + break; + + case 0xe: // EGA 640x200 16-color + info->type = VIDEO_EGA; + info->pixels_width = 640; + info->pixels_height = 200; + info->bytes_per_line = 80; + info->bits_per_pixel = 1; + info->num_planes = 4; + segment = 0xA000; + break; + + case 0xf: // EGA 640x350 4-color + info->type = VIDEO_EGA; + info->pixels_width = 640; + info->pixels_height = 350; + info->bytes_per_line = 80; + info->bits_per_pixel = 1; + info->num_planes = 2; + segment = 0xA000; + break; + + case 0x10: // EGA 640x350 16-color + info->type = VIDEO_EGA; + info->pixels_width = 640; + info->pixels_height = 350; + info->bytes_per_line = 80; + info->bits_per_pixel = 1; + info->num_planes = 4; + segment = 0xA000; + break; + + case 0x11: // VGA 640x480 2-color + case 0x12: // VGA 640x480 16-color + info->type = VIDEO_VGA; + info->pixels_width = 640; + info->pixels_height = 480; + info->bytes_per_line = 80; + info->bits_per_pixel = 1; + info->num_planes = 4; + segment = 0xA000; + break; + + case 0x13: // VGA 320x200 256-color + info->type = VIDEO_VGA; + info->pixels_width = 320; + info->pixels_height = 200; + info->bytes_per_line = 320; + info->bits_per_pixel = 8; + info->num_planes = 1; + segment = 0xA000; + break; + default: - return 0; + info->type = VIDEO_UNKNOWN; + // Let's put in some default coordinates at leas + info->pixels_width = 640; + info->pixels_height = 200; + segment = 0; + } + + info->begin = MK_FP(segment, info->page * bda_get_video_page_size()); +} + +static inline uint16_t __far * get_video_char(const struct modeinfo *info, unsigned int x, unsigned int y) +{ + return (uint16_t __far *) (info->begin + (y * info->bytes_per_line) + (x * 2)); +} + +static inline uint8_t __far * get_video_scanline(const struct modeinfo *info, unsigned int y) +{ + if (info->odd_scanline_offset) { + return info->begin + + (y%2 * info->odd_scanline_offset) + + (y/2 * info->bytes_per_line); + } else { + return info->begin + + (y * info->bytes_per_line); } } +struct videoregs { + uint16_t dummy; +}; +static void save_video_registers(struct videoregs *regs) +{ + // TODO +} + +static void restore_video_registers(struct videoregs *regs) +{ + // TODO +} + +static inline void vga_select_plane(unsigned plane) +{ + // TODO +} #endif |