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#ifndef INT10_H
#define INT10_H
#include <stdint.h>
#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;
}
static inline uint16_t bda_get_word(unsigned int offset) {
uint16_t __far *p = MK_FP(BIOS_DATA_AREA_SEGMENT, offset);
return *p;
}
static inline uint8_t bda_get_byte(unsigned int offset) {
uint8_t __far *p = MK_FP(BIOS_DATA_AREA_SEGMENT, 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_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)
{
return MK_FP(0xB800, (page * bda_get_video_page_size())
+ ((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
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