vga_set_indexed
vga_set_indexed(reg, VGA_CRTC_ADDRESS, VGA_CRTC_DATA, i, v);
vga_set_indexed(reg, VGA_SEQ_ADDRESS, VGA_SEQ_DATA, i, v);
vga_set_indexed(reg, VGA_GC_ADDRESS, VGA_GC_DATA, i, v);
void vga_set_indexed(int, int, int, uint8_t, uint8_t);