When I start my at91sam9m10g45 board,I can mount root FS normally.But I find I can't use some command as follow:

[root@Perlove /]# ifconfig
ifconfig: /proc/net/dev: No such file or directory
[root@Perlove /]# fdisk -l
fdisk: /proc/partitions: No such file or directory
Segmentation fault

When I connect my Udisk to this board,it reports:

[root@Perlove /]# usb 1-2: new high speed USB device using atmel-ehci and addres
s 2
usb 1-2: New USB device found, idVendor=1976, idProduct=6025
usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-2: Product: Flash Disk
usb 1-2: Manufacturer: CBM
usb 1-2: SerialNumber: 16102000080CF902
usb 1-2: configuration #1 chosen from 1 choice
scsi0 : SCSI emulation for USB Mass Storage devices
scsi 0:0:0:0: Direct-Access CBM Flash Disk 5.00 PQ: 0 ANSI: 2
sd 0:0:0:0: [sda] 2063872 512-byte hardware sectors: (1.05 GB/1007 MiB)
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

but I can't find sda or sda1 in /dev or elsewhere,thus I can't read or write my USB mass storage.

If you know the problem or the way to detect the problem ,please write to armboy@sohu.com.Thank you for your attention.