DMAMODE_LOOP
(char *)end - (char *)start, NULL, DMAMODE_READ | DMAMODE_LOOP,
DMAMODE_WRITE | DMAMODE_LOOP, BUS_DMA_NOWAIT);
DMAMODE_WRITE | DMAMODE_LOOP, BUS_DMA_NOWAIT);
DMAMODE_WRITE | DMAMODE_LOOP, BUS_DMA_NOWAIT);
DMAMODE_READ | DMAMODE_LOOP, BUS_DMA_NOWAIT);
(char *)start, NULL, DMAMODE_READ | DMAMODE_LOOP, BUS_DMA_NOWAIT);
(char *)start, NULL, DMAMODE_WRITE | DMAMODE_LOOP, BUS_DMA_NOWAIT);