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pvvx / TlsrComSwireWriter

TLSR826x/825x COM port Swire Writer
The Unlicense
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Bit errors while reading flash #9

Closed thxomas closed 5 months ago

thxomas commented 5 months ago

Hello,

Thanks for this RE work, it has been very valuable for my project (reversing hanshow firmware)

I extracted a flash firmware from a TLSR8359 using TLSR825xComFlasher.py and noticed strange bit errors in the extracted file. Same errors happen using ComSwireReader825x.py

After testing, I had to comment this line to keep bitmask at 0x20 in function sws_decode() and this fixed the errors :

https://github.com/pvvx/TlsrComSwireWriter/blob/b08c5ea35fde36316e5d644d45e255bca81f82f6/TLSR825xComFlasher.py#L83

I'm not sure if the bitmask change is intentional after 1st bit or a forgotten debug command or a 835x discrepancy. However, this info may be useful for somebody.

pvvx commented 5 months ago

It depends on the clock frequency

https://github.com/pvvx/TlsrTools/blob/master/DOCs/SWM_S.pdf