I guess I will use this thread just for reporting my progress
Maybe someone else can use it.
I was able to read/write the flash of the DSP. I am using Ubuntu 18.04. After downloading the toolchain:
$ tar xf blackfin-toolchain-2014R1_45-RC2.x86_64.tar.bz2
$ cd opt/uClinux/bfin-linux-uclibc/bin
$ sudo ./bfin-jtag -q
You can also do it without sudo, but you probably (like me) would have to fiddle around with udev to get the right permissions on the device first
> cable OOCDLink-s
Connected to libftdi driver.
> detect
Should give you a list with some info on the device like ID, Manufacturer etc...
> initbus bf52x
> detectflash 0x20000000
Should give you a bunch of info on the flash, like voltages, timings, size, ...
> readmem 0x20000000 0x1000000 flash.bin
This will read the flash into flash.bin. I hope that command is correct, aspecially the size. Should be 16M as reported by detectflash, but according to the memory map of the Blackfin it has only 4 banks of 1M for flash... I don't get it, just hope it will work.
After that I connected the defect board, did the whole progress with bfin-jtag again but instead of reading I wrote the flash:
> flashmem 0x20000000 flash.bin
Edit: Don't do that! I guess I broke something in the DSP with that command Reading takes quite a long time (5 min or so) and writing is even slower...but it will hopefully do the job.
urjtag (which is bfin-jtag) should also support FT2232H directly by changing the cable name from OOCDLink-s to FT2232. I haven't tried it, because "never touch a running system".
I am a bit worried about the flash file. After compression there are only ~980kb left. There are quite a lot FF in there. I also attached the file, maybe it can help someone. I will get back here, when the flash process has finished, guess it will take nearly an hour.