Before disassembling, need to understand the layout of the bin file.
Conclusions on just scanning the binary and strings
1) Layout of D2 firmware similar to U3
2) Layout of D2 firmware similar to M-bird rom !!!!
The firmware for M-bird XY-22 Player can be downloaded herehttp://www.m-bird.se/software/XY-22/XY22SMV1320.rom
M-bird XY-22 based on TCC76x (ARM 940T core)
Cowon U3 based on TCC77x (ARM 946 core)
Cowon D2 based on TTC78x (ARM 926/946 core)
My analysis suggest this is 'coz all three use a common format created by Telechips SDK for ARM. Possibly even the preloader is the similar for all three
These are encouraging signs....crack one and we are close to all!
I am sure many telechip licencees that are looking for smaller time to market will use their reference solution as is (including IRiver??)
I suggest the U3 progress ought to be relooked and taken forward 'coz my current knowledge (from iaudiophile forums) tells me that there is
***** NO RECOVERY MODE *****
U3 Page --> http://www.rockbox.org/twiki/bin/view/Main/IaudioU3Info