does uclinux1.3 support usb?

Just to be more explicit about what wentao said earlier (in a different thread), if you want to get usb mass storage support working (usb-storage), you'll need to create a DMA zone in your memory setup. Modify arch/nios2nommu/mm/init.c, toward the bottom of the paging_init() function. I changed the zone creations to look like:

zones_size = (4*1024*1024) >> PAGE_SHIFT;
zones_size = ((end_mem - PAGE_OFFSET) >> PAGE_SHIFT) - zones_size;