Load usb module
 ----------------------

%lsmod    ;list loaded module

usb-uhci
ehci-hcd  ;Enhanced Host Controller ( EHCI ) -USB 2.0
usbcore   ;??

%modinfo  ( module-name )  ;module info.

%insmod   ( module-name )  ;?? fr. driver doc
or
%modprobe ( module-name )  ;?? fr. network

 Load usb-storage module
 -----------------------

%modprobe usb-storage

Because usb storage is be saw as an scsi-disk, so ..

 Load scsi-disk module
 -----------------------

%modprobe sd_mod ( or sd_mod.ko )
  
         / chk kernel config : CONFIG_BLK_DEV_SD=m ??  

[ok]

plug-in usb-flash & look

%fdisk -l ;list all disk
=>/dev/sd[a-p]* ;( sd )scsi disk

%mount dev target-dir

mount it done!