wcfb_bitblt
static void wcfb_bitblt(struct wcfb_softc *, int, int, int, int, int,
wcfb_bitblt(sc, x, y, x, y, wi, he, WC_ROP_COPY);
wcfb_bitblt(sc, x, y, x, y, wi, he, WC_ROP_XOR);
wcfb_bitblt(sc, x, y, x, y, wi, he, WC_ROP_XOR);
wcfb_bitblt(sc, xs, y, xd, y, width, height, WC_ROP_COPY);
wcfb_bitblt(sc, x, ys, x, yd, width, height, WC_ROP_COPY);