step14 usb设备不能用，请高手赐教

以下是插入u盘后的显示
usb 1-1: new full speed USB device using s3c2410-ohci and address 4
usb 1-1: New USB device found, idVendor=0000, idProduct=0000
usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-1: Product: Removable Drive
usb 1-1: SerialNumber: 14270004100871000024
usb 1-1: configuration #1 chosen from 1 choice
scsi0 : SCSI emulation for USB Mass Storage devices
scsi 0:0:0:0: Direct-Access                               0    PQ: 0 ANSI: 0 CCS
sd 0:0:0:0: [sda] 7831552 512-byte hardware sectors: (4.00 GB/3.73 GiB)
sd 0:0:0:0: [sda] Write Protect is off
sd 0:0:0:0: [sda] Assuming drive cache: write through
sd 0:0:0:0: [sda] Assuming drive cache: write through
sda: sda1
sd 0:0:0:0: [sda] Attached SCSI removable disk
FAT: utf8 is not a recommended IO charset for FAT filesystems, filesystem will be case sensitive!
此外，usb鼠标也不能用。
向高手求解

烧写的是光盘的么？换一个u盘试试