static void write_font(unsigned char *buf, unsigned font_height)
{
unsigned char seq2, seq4, gc4, gc5, gc6;
unsigned i;
/* save registers
set_plane() modifies GC 4 and SEQ 2, so save them as well */
outport(VGA_SEQ_INDEX, 2);
seq2 = inport(VGA_SEQ_DATA);
outport(VGA_SEQ_INDEX, 4);
seq4 = inport(VGA_SEQ_DATA);
/* turn off even-odd addressing (set flat addressing)
assume: chain-4 addressing already off */
outport(VGA_SEQ_DATA, seq4 | 0x04);
outport(VGA_GC_INDEX, 4);
gc4 = inport(VGA_GC_DATA);
outport(VGA_GC_INDEX, 5);
gc5 = inport(VGA_GC_DATA);
/* turn off even-odd addressing */
outport(VGA_GC_DATA, gc5 & ~0x10);
outport(VGA_GC_INDEX, 6);
gc6 = inport(VGA_GC_DATA);
/* turn off even-odd addressing */
outport(VGA_GC_DATA, gc6 & ~0x02);
/* write font to plane P4 */
set_plane(2);
/* write font 0 */
for(i = 0; i < 256; i++)
{
//vmemwr(16384u * 0 + i * 32, buf, font_height);
memcpy((char*)buf, (char*)(i*32 + 0xA0000), font_height);
buf += font_height;
}
#if 0
/* write font 1 */
for(i = 0; i < 256; i++)
{
vmemwr(16384u * 1 + i * 32, buf, font_height);
buf += font_height;
}
#endif
/* restore registers */
outport(VGA_SEQ_INDEX, 2);
outport(VGA_SEQ_DATA, seq2);
outport(VGA_SEQ_INDEX, 4);
outport(VGA_SEQ_DATA, seq4);
outport(VGA_GC_INDEX, 4);
outport(VGA_GC_DATA, gc4);
outport(VGA_GC_INDEX, 5);
outport(VGA_GC_DATA, gc5);
outport(VGA_GC_INDEX, 6);
outport(VGA_GC_DATA, gc6);
}
void VGAWriteFont(uint8_t* buffer, uint8_t font_height) {
/* These are the registers we have to save and restore. */
uint8_t seq2, seq4, gc4, gc5, gc6;
outb(VGA_SEQ_INDEX, 2);
seq2 = inb(VGA_SEQ_DATA);
outb(VGA_SEQ_INDEX, 4);
seq4 = inb(VGA_SEQ_DATA);
/* turn off even-odd addressing (set flat addressing)
assume: chain-4 addressing already off */
outb(VGA_SEQ_DATA, seq4 | 0x04);
outb(VGA_GC_INDEX, 4);
gc4 = inb(VGA_GC_DATA);
outb(VGA_GC_INDEX, 5);
gc5 = inb(VGA_GC_DATA);
/* turn off even-odd addressing */
outb(VGA_GC_DATA, gc5 & ~0x10);
outb(VGA_GC_INDEX, 6);
gc6 = inb(VGA_GC_DATA);
/* Turn off even-odd addressing. */
outb(VGA_GC_DATA, gc6 & ~0x02);
/* Write font to plane P4. */
VGASetPlane(2);
/* Write font. */
for(size_t i = 0; i < 256; i++) {
vmemwr(16384u * 0 + i * 32, buffer, font_height);
buffer += font_height;
}
/* Restore registers. */
outb(VGA_SEQ_INDEX, 2);
outb(VGA_SEQ_DATA, seq2);
outb(VGA_SEQ_INDEX, 4);
outb(VGA_SEQ_DATA, seq4);
outb(VGA_GC_INDEX, 4);
outb(VGA_GC_DATA, gc4);
outb(VGA_GC_INDEX, 5);
outb(VGA_GC_DATA, gc5);
outb(VGA_GC_INDEX, 6);
outb(VGA_GC_DATA, gc6);
}