region 76 has a size of 2,486,272 bytes on my 3750, but does not exist on the 3450.
@voyager56
All experiment done with 37xx or in 34xx?
I just realize the dump region 43 from same unit with different firmware is much different.
@kunix
Can you share some hints on this matter (how to recover from 34xx) ?
I know - Спасение утопающих - дело самих утопающих.
But still ...
Finally I solved my problem very simple way - replace my region 41 with the same region dump from other unit. Now I have clone unit with LMT subscription. Funny, isn't.
Now I have unit with duplicated UnitID. This is no problem for me, but I was curious is it possible easy way to change UnitID. I discovered that it's possible. Even in a different ways. But at the moment I don't know how to retain HWID after this change.
sound good ...
I have my original backup before make any trial but once flashback the UnitID is recovered but not the model number.
Anyway in the last_id.bin still FF FF FF FF
I never had FFFFFFF in the last_id.bin, I had some "funny" situations, when in 34 region was different UnitID than in region 41. Then last_id.bin had number from 34 region, and each time I reloaded my unit, each time unit executed update.txt. I must remove micro SD to stop execution.
same funny I had.
now your unit also recovered the model number?
But now I'm investigating how to change UnitID and retain HWID.
And what I discovered:
UnitID stored in region 34 is decimal UnitID treated as "Unsigned long" and stored as Intel HEX. For example UnitID 1234567890 will be D2029649. In region 41 is applyed some "encryption". The bytes sequence stored in region 41 is the same bytes sequence from region 34 but XOR'ed with FF and then with C3 5A.
So the UnitID from region 34 (D2029649) in region 41 is stored like EEA7AAEC.
In region 41 from Nuvi 3490 there are 24 copies of this UnitID.
EDIT:
BTW in region 41 from unit which flashed from 3790 to 3490 there are 65 copies of UnitID.
NVRAM in 3490 is about 2MB and NVRAM in 3790 is about 6MB
Last edited by voyager56; 2nd December 2011 at 08:56 PM.
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