######################Motorola SB4200 Modem Serial Port Notes##########
#This Modem is running VxWorks, not Linux
#https://en.wikipedia.org/wiki/VxWorks
#At this point I do not have a shell on this machine
#I can see the boot process and can choose to 
#1 Boot from FLASH
#2 Network Boot 

###Usefull links###
http://thecablemodemguide.tripod.com/page27.htm
http://thecablemodemguide.tripod.com/page25.htm
https://wiki.openwrt.org/oldwiki/openwrtdocs/hardware/motorola/sb4200
https://forum.openwrt.org/viewtopic.php?id=25879
http://the-secrete-lab.blogspot.com/2011/04/hacking-cable-modems-for-higher-speeds.html

#I've found two very old posts that say that they have created openwrt images for this device
#saidly they both used MegaUpload to post the files, so they are long gone.
#This devices only has 2MB FLash and 8MB RAM, 
#So if anything can be done with it, it would have to be very streamlined.

#######IMAGES#####
http://thecablemodemguide.tripod.com/41004.jpg
https://goo.gl/photos/bDzL3EZC4JxuEgwbA
https://goo.gl/photos/FV4grBr8bBxudCDSA

#####Connect with serial port using Screen#####
#make sure you have permissions to access serial port
sudo usermod -a -G dialout <user> #logout and back in
#then connect
screen /dev/ttyUSB0 38400,cs8,-parenb,-cstopb,-hupcl

#####serial output######
SB4200











                            VxWorks System Boot


Copyright 1984-1996  Wind River Systems, Inc.





CPU: BCM3345
FLASH: Intel 28F160C3T
Version: 5.3.1
BSP version: 1.1/0
Creation date:




Press any key to stop auto-boot...
 0
auto-booting...

Bootrom version: SB4200-0.4.4.0-SCM06-NOSH
Validating image bs1
Validating image bs2
Comparing image 1 and 2
Booting from standalone image 1 at 0xBFC40000

Starting at 0xbfc40000...