 Teddy Boomk kudos Received
join:2007-01-29
Toronto, ON
kudos:5 | reply to mlord
Re: Upgrading Firmware on Thompson DCM475 said by mlord:So I'm pretty close to hook-up time. Once I get the new 'duino going, the first task is to rip the 02.08 firmware a few times via different sequences, and do binary compares to judge the reliability of the communications. Then try erasing and reprogramming just the 02.08 firmware, and do readback/verify again.
If that all works, I'll get hold of the 02.16 modem and snatch a copy of the latest firmware from it. Install the USBJTAG software and take a look at how cable modem flash is organized on other modems, it will help a lot. If you need a flash dump from a modem, I can pass that along..
In particular, what you'll find is that some of the firmware will be human readable. Try searching for "DCM" and "docsis" in a hex editor. If you've read the firmware properly you should find strings like that. When my friend read a DCM425 chip for me, the bytes always came out flipped:If I load 425-1.bin into USBJTAG and then inspect image0 I see the
string as follows:
CD4M525-.2803.-1118032S-.Sib.n
Flip the bits and I get:
DCM425-52.08.31-110823-SS.bin.
So maybe it is all just pairwise swapped?!?!  So I googled around a bit and found HEX Workshop, which conveniently has a byte swap feature. Not long after that I had a working ST52.08.31 image.
»www.hexworkshop.com/
Unfortunately no Sayal in Ottawa:
»www.sayal.com/zinc/zinc_contactus.asp
But there must be an electronics supply place.. Not sure about test clips, but they aren't that obscure, so the odds can't be too bad.
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electronicsguru.ca/for_sale/Cablemodems |
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 TSI GabePremium,VIP
join:2007-01-03
Chatham, ON
kudos:2 | That's called Endianness
»en.wikipedia.org/wiki/Endianness
x86 are little endian
While in this case is likely MIPS based which is usually big endian.
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TSI Gabe - TekSavvy Solutions Inc.
Authorized TSI employee ( »TekSavvy FAQ »Official support in the forum )
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Teddy Boomk kudos Received
join:2007-01-29
Toronto, ON
kudos:5 | said by TSI Gabe:That's called Endianness Thanks! I've heard of little endian and big endian before, and I probably even dealt with the ideas a little 15 years ago, but I sure didn't make the connection.
I mentioned that I'm an analog guy right? 
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electronicsguru.ca/for_sale/Cablemodems |
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