usb下载驱动安装

1.我买的板子是TQ6410，是用wince6.0启动的，现在打开secureCRT,接好电源和串口线，按住空格键，进入 下面的界面
Microsoft Windows CE Bootloader Common Library Version 1.4 Built Jan 14 2012 17:34:32
Microsoft Windows CE Bootloader for the EmbedSky TQ6410 Version 3.6 Built Jan 14 2012
DDRRAM capacity is 256MB
Press [ENTER] to launch image stored on boot media, or [SPACE] to enter boot monitor.
Initiating image launch in 1 seconds.
Ethernet Boot Loader Configuration:

----------- Connectivity Settings ------------
0) IP address  : [192.168.1.6]
1) Subnet mask : [255.255.255.0]
2) DHCP : [*Enabled]
3) Program DM9000A MAC address : [10:23:45:67:89:AB]
--------- Boot Configuration Section ---------
4) Reset to factory default configuration
5) Startup Action after Boot delay : [Launch Existing OS image from Storage]
6) Boot delay: 1 seconds
R) Read Configuration(TOC)
W) Write Configuration Data(TOC) Right Now
------- Kernel Booting Option Section --------
K) KITL Configuration           : [Disabled]
I) KITL Connection Mode         : [*Interrupt]
C) Force Clean Boot Option      : [*True]
H) Hive Clean on Boot-time      : [*False]
P) Format Partition on Boot-time: [*False]
------------- NAND Flash Section -------------
A) Erase All Blocks(Format FIL)
7) Format VFL (Format FIL + VFL Format)
8) Format FTL (Erase FTL Area + FTL Format)
M) MLC Low level test
--------- Download and Launch Section --------
S) Switch Boot Device : [SD/MMC]  
        { Options : *Ethernet, USB_DNW, SD/MMC }
J) Progress Bar Type : [CambridgeBlue]  
        { Options : Yellow,  Gray,  CambridgeBlue,  Deongaree,  Green,  reserve1,  reserve2, }
T) Download Target: [*Download to RAM]
D) Download or Program image(OS image will be launched)
B) Download and Write Logo Picture to NAND Storage
Q) SD Download or Program image(OS image will be launched)
L) LAUNCH existing Boot Media image
Enter your selection:

选什么才会 发现硬件，顺利安装USB下载驱动？

2.我的板子linux启动不起来，从SD卡启动，屏上显示如下图所示，是为什么？

先按5，选择USB_DNW,再按D下载镜像