I have prepared a firmware and tutorial to Install Debian here, this time without the need for serial port. I have tested this, and it seems that everything works. But of course I will not be responsible if anything happens. If you think there are some missing, unclear or inaccurate steps, or if you doubt about something, then don’t install it. If you have anything to ask just email to yohanes [at] gmail.com, or just post your questions as comments.
NOTE: the web update method only works on agestar ncb3ast, other models can work by using serial port and latest patch for kernel source (2.6.29 or later).