PC：Personal Computer（这里用的Win7）
CM：Cable MODEM（芯片：BCM93349DCM）
一、预置条件
1、PC上已安装TFTP Server，比如tftpd32；
2、PC上已安装USB转串口驱动，可以通过串口与CM通信；
3、PC上已有编译好的CM Fireware。
二、网络连接
1、PC与CM分别通过串口和网口相连；
2、手工设置PC固定IP，比如192.168.100.2；
3、在PC端打开tftpd32，设置好路径和服务器接口。
三、升级过程
通过串口操作，有4步：设置IP建立通信--使用TFTP上传Fireware--升级--重启。
粗体蓝字是要输入的信息，不需要修改的直接回车继续。
Enter '1', '2', or 'p' within 2 seconds or take default...
p
Board IP Address [10.3.45.189]: 192.168.100.1
Board IP Mask [255.255.255.0]:
Board IP Gateway [10.3.45.254]: 192.168.100.2
Board MAC Address [00:10:18:ff:ff:ff]:
Internal/External phy? (e/i)[i]
Init EMAC...
Autonegotiation... successful
Main Menu:
==========
b) Boot from flash
g) Download and run from RAM
d) Download and save to flash
e) Erase flash sector
m) Set mode
s) Store bootloader parameters to flash
i) Re-init ethernet
r) Read memory
w) Write memory
j) Jump to arbitrary address
z) Reset
d
TFTP Get Selected
Board TFTP Server IP Address [10.3.45.42]: 192.168.100.2
Enter filename [DVB-C8000BG_GD_cm.bin]: ecram_sto.bin
Destination: a0b00000
Starting TFTP of ecram_sto.bin from 192.168.100.2
Getting ecram_sto.bin using octet mode
Init EMAC...
Autonegotiation... successful
Tftp timeout...
..................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
Tftp complete
Received 1021660 bytes
Image 3 Program Header:
Signature: 3349
Control: 0005
Major Rev: 0003
Minor Rev: 0000
Build Time: 2015/3/20 01:57:01 Z
File Length: 1021568 bytes
Load Address: 80010000
Filename: ecram_sto.bin
HCS: 342e
CRC: 9556335e
CRC Verified
Destination image
0 = bootloader
1/2 = CM image
3 = specify flash offset
4 = asymmetric image 2
5 = alternate image 1 (SPI flash block 1)
(0-3)[2]: 1
Image 1 Program Header:
Signature: 3349
Control: 0005
Major Rev: 0003
Minor Rev: 0000
Build Time: 2015/3/19 02:15:36 Z
File Length: 1021358 bytes
Load Address: 80010000
Filename: ecram_sto.bin
HCS: 6267
CRC: fbb8d0fa
Found image 1 at offset 20000
Erasing before writing at offset 20000...
SpiFlashWrite: Writing flash at 00020000
Store parameters to flash? [n]
Main Menu:
==========
b) Boot from flash
g) Download and run from RAM
d) Download and save to flash
e) Erase flash sector
m) Set mode
s) Store bootloader parameters to flash
i) Re-init ethernet
r) Read memory
w) Write memory
j) Jump to arbitrary address
z) Reset
w) Write memory
j) Jump to arbitrary address
z) Reset
z
升级成功并重启。
四、严重注意
升级时CM和PC的IP都是手动配置！
CM IP = Board IP
PC IP = Board TFTP Server IP
因为CM启动时按p进入升级模式，就不会再启动DHCP模块了，所以CM不会通过DHCP给PC分配IP地址。