rem: con->module->fill_glyph(0, 0, con->columns, con->lines, ' ', con->attr);
add: con->module->clear(con->attr);
context: erase_screen(struct console_desc *con, erase_screen_mode mode){	switch (mode) {		case SCREEN_ERASE_WHOLE:			con->module->fill_glyph(0, 0, con->columns, con->lines, ' ', con->attr);			break;		case SCREEN_ERASE_UP:			con->module->fill_glyph(0, 0, con->columns, con->y + 1, ' ', con->attr);			break;		case SCREEN_ERASE_DOWN:			con->module->fill_glyph(con->y, 0, con->columns, con->lines - con->y, ' ', con->attr);			break;		default:			return;	}}