I assume that you have identified serial port connections on the board to to get the boot log. Looking at the photo there seem to be a few possible options, can you say where the connections are.?
~1cm above "HG658BZV Ver. A" in the photo you can see the 5 pin header, with the bar code sticker to the right. From left, Tx, Gnd, 3.3v, N/A, Rx. Serial settings: 115200baud, 8bits, 1stop bit, no parity.
Also can you say what the firmware version is shown by the HG658? If not the command "xdslcmd --version" should give it if you log in via telnet or on the serial port. It may also be shown on the start page of the web gui.
Telnet does not appear to be running. The status page of the gui:
Product type HG658c
Device ID F83DFF-Q8Y7NA9382600371
Hardware version HG658BZV VER.A
Software version V100R001C172B211
Batch number BC172P0.211.A2pv6F037g.d24b1
MAC Address 00:66:4B:32:CE:08
System up time 0 days 0 hours 1 minutes 43 seconds
I googled "CFE version 1.0.38-" and found information that indicated the bootloader is locked, i.e. it will not flash unsigned images. See
http://unlocka1.wordpress.com/prg_av/Regards,
Dermot.