2630 FSIG/ext. FSIG/MCU checksum/what else? - GSM-Forum

krisha · 11-17-2008, 21:59

hi,

it don't happen often that i ask for help, but now i'm little bit stuck. It's a small project and I put a lot of time already on FSIG, extended FSIG etc.

Maybe someone has an idea or is interested in some information exchange

I think on JAF, when you do an unlock there is somehwere a procedure i also need to do.

The 2630 uses FSIG protection for the 1st megabyte - this is working (cloned). After the 1st MB there is another checksum (divided to ranges) which seems to be calculated in software (recalced/cloned). The 2630 also uses the MCU checksum (recalced/bypassed).

I recalculated/knock'ed out all 3 checksums, phone gets network, but after 30 seconds phone powers off. Why?

I also cloned JAF unlock, but this did not solve the problem. So it seems to be a code part NOT inside MCU. I also tried with PM (read after unlock and write back after own modification), but this also didn't solve the power down.

What else can it be? What does JAF do when it unlocks the 2630?

You also can contact me by PM if you don't want to publish the information :-)

thx!

krisha · 11-19-2008, 09:54

seems like FSIG is timing critical or MUST be done from RAM on 2630. On 3100 it doesn't seem to matter... (thx g3gg0 for pushing me to right direction :-) )

11-17-2008, 21:59	#1 (permalink)
krisha Junior Member Join Date: May 2005 Posts: 6 Member: 142832 Status: Offline Thanks Meter: 1	2630 FSIG/ext. FSIG/MCU checksum/what else? hi, it don't happen often that i ask for help, but now i'm little bit stuck. It's a small project and I put a lot of time already on FSIG, extended FSIG etc. Maybe someone has an idea or is interested in some information exchange I think on JAF, when you do an unlock there is somehwere a procedure i also need to do. The 2630 uses FSIG protection for the 1st megabyte - this is working (cloned). After the 1st MB there is another checksum (divided to ranges) which seems to be calculated in software (recalced/cloned). The 2630 also uses the MCU checksum (recalced/bypassed). I recalculated/knock'ed out all 3 checksums, phone gets network, but after 30 seconds phone powers off. Why? I also cloned JAF unlock, but this did not solve the problem. So it seems to be a code part NOT inside MCU. I also tried with PM (read after unlock and write back after own modification), but this also didn't solve the power down. What else can it be? What does JAF do when it unlocks the 2630? You also can contact me by PM if you don't want to publish the information :-) thx!

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11-19-2008, 09:54	#2 (permalink)
krisha Junior Member Join Date: May 2005 Posts: 6 Member: 142832 Status: Offline Thanks Meter: 1	seems like FSIG is timing critical or MUST be done from RAM on 2630. On 3100 it doesn't seem to matter... (thx g3gg0 for pushing me to right direction :-) )