diff options
Diffstat (limited to 'int10vga.h')
| -rw-r--r-- | int10vga.h | 31 |
1 files changed, 30 insertions, 1 deletions
@@ -5,6 +5,7 @@ #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" \ @@ -16,6 +17,11 @@ static uint8_t int10_get_video_mode(uint8_t *screenwidth, uint8_t *videopage); __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; +} + static inline uint16_t bda_get_word(unsigned int offset) { uint16_t __far *p = MK_FP(BIOS_DATA_AREA_SEGMENT, offset); return *p; @@ -26,10 +32,14 @@ static inline uint8_t bda_get_byte(unsigned int offset) { return *p; } +#define bda_get_ebda_segment() bda_get_word(0x0e) + #define bda_get_video_mode() bda_get_byte(0x49) #define bda_get_num_columns() bda_get_word(0x4a) #define bda_get_video_page_size() bda_get_word(0x4c) -//#define bda_get_tick_count() bda_get_dword(0x6c) +#define bda_get_cur_video_page() bda_get_word(0x62) + +#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) @@ -38,4 +48,23 @@ static inline uint16_t __far * get_video_char(uint8_t page, unsigned int x, unsi + ((y * bda_get_num_columns()) + x) * 2); } +static inline uint8_t __far * get_video_scanline(uint8_t mode, uint8_t page, unsigned int y) +{ + switch (mode) { + 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); + + default: + return 0; + } +} + + + #endif |